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Sample records for muscle mass influence

  1. Subclinical hypothyroidism has little influences on muscle mass or strength in elderly people.

    Science.gov (United States)

    Moon, Min Kyong; Lee, You Jin; Choi, Sung Hee; Lim, Soo; Yang, Eun Joo; Lim, Jae-Young; Paik, Nam-Jong; Kim, Ki Woong; Park, Kyong Soo; Jang, Hak C; Cho, Bo Youn; Park, Young Joo

    2010-08-01

    Sarcopenia, the age-related decline in muscle mass, affects the muscle strength and muscle quality, and these changes decrease functional capacity. The prevalence of thyroid dysfunction increases with age, and changes in thyroid hormone level lead to neuromuscular deficits. We investigated the effects of subclinical hypothyroidism on the muscle mass, strength or quality in elderly people. One thousand one hundred eighteen subjects aged > or = 65 yr were randomly selected from a local population and classified into a euthyroid (280 men and 358 women), subclinically hypothyroid (61 men and 75 women), or overtly hypothyroid (7 men and 16 women) group. Although women with subclinical hypothyroidism had a higher prevalence of sarcopenia, defined according to the ratio of appendicular skeletal muscle mass to the square of height, muscle mass, strength or quality did not differ in relation to thyroid status in men or in women. Multivariate analysis including age, diabetes, hypertension, acute coronary event, alcohol, smoking, presence of pain, physical activity score, and lipid profile, showed that thyroid-stimulating hormone level was not associated with muscle mass, strength or quality. In conclusion, subclinical hypothyroidism has little influences on muscle mass, strength or quality, and may not be associated with sarcopenia.

  2. The influence of different muscle mass measurements on the diagnosis of cancer cachexia.

    Science.gov (United States)

    Blauwhoff-Buskermolen, Susanne; Langius, Jacqueline A E; Becker, Annemarie; Verheul, Henk M W; de van der Schueren, Marian A E

    2017-08-01

    Progressive loss of muscle mass is a major characteristic of cancer cachexia. Consensus definitions for cachexia provide different options to measure muscle mass. This study describes the effect of different methods to determine muscle mass on the diagnosis of cancer cachexia. In addition, the association of cachexia with other features of cachexia, quality of life, and survival was explored. Prior to chemotherapy, cachexia was assessed by weight loss, body mass index, and muscle mass measurements, the latter by mid-upper arm muscle area (MUAMA), computed tomography (CT) scans, and bio-electrical impedance analysis (BIA). In addition, appetite, inflammation, muscle strength, fatigue, quality of life, and survival were measured, and associations with cachexia were explored. Included were 241 patients with advanced cancer of the lung (36%), colon/rectum (31%), prostate (18%), or breast (15%). Mean age was 64 ± 10 years; 54% was male. Prevalence of low muscle mass was as follows: 13% with MUAMA, 59% with CT, and 93% with BIA. In turn, the prevalence of cachexia was 37, 43, and 48%, whereby weight loss >5% was the most prominent component of being defined cachectic. Irrespective of type of muscle measurement, patients with cachexia presented more often with anorexia, inflammation, low muscle strength, and fatigue and had lower quality of life. Patients with cachexia had worse overall survival compared with patients without cachexia: HRs 2.00 (1.42-2.83) with MUAMA, 1.64 (1.15-2.34) with CT, and 1.50 (1.05-2.14) with BIA. Although the prevalence of low muscle mass in patients with cancer depended largely on the type of muscle measurement, this had little influence on the diagnosis of cancer cachexia (as the majority of patients was already defined cachectic based on weight loss). New studies are warranted to further elucidate the additional role of muscle measurements in the diagnosis of cachexia and the association with clinical outcomes. © 2017 The Authors

  3. Insulin Resistance Negatively Influences the Muscle-Dependent IGF-1-Bone Mass Relationship in Premenarcheal Girls.

    Science.gov (United States)

    Kindler, J M; Pollock, N K; Laing, E M; Jenkins, N T; Oshri, A; Isales, C; Hamrick, M; Lewis, R D

    2016-01-01

    IGF-1 promotes bone growth directly and indirectly through its effects on skeletal muscle. Insulin and IGF-1 share a common cellular signaling process; thus, insulin resistance may influence the IGF-1-muscle-bone relationship. We sought to determine the effect of insulin resistance on the muscle-dependent relationship between IGF-1 and bone mass in premenarcheal girls. This was a cross-sectional study conducted at a university research center involving 147 girls ages 9 to 11 years. Glucose, insulin, and IGF-1 were measured from fasting blood samples. Homeostasis model assessment of insulin resistance (HOMA-IR) was calculated from glucose and insulin. Fat-free soft tissue (FFST) mass and bone mineral content (BMC) were measured by dual-energy x-ray absorptiometry. Our primary outcome was BMC/height. In our path model, IGF-1 predicted FFST mass (b = 0.018; P = .001), which in turn predicted BMC/height (b = 0.960; P IGF-1 predicted BMC/height (b = 0.001; P = .002), but not after accounting for the mediator of this relationship, FFST mass. The HOMA-IR by IGF-1 interaction negatively predicted FFST mass (b = -0.044; P = .034). HOMA-IR had a significant and negative effect on the muscle-dependent relationship between IGF-1 and BMC/height (b = -0.151; P = .047). Lean body mass is an important intermediary factor in the IGF-1-bone relationship. For this reason, bone development may be compromised indirectly via suboptimal IGF-1-dependent muscle development in insulin-resistant children.

  4. Muscle strength and regional lean body mass influence on mineral bone health in young male adults.

    Science.gov (United States)

    Guimarães, Bianca Rosa; Pimenta, Luciana Duarte; Massini, Danilo Alexandre; Dos Santos, Daniel; Siqueira, Leandro Oliveira da Cruz; Simionato, Astor Reis; Dos Santos, Luiz Gustavo Almeida; Neiva, Cassiano Merussi; Pessôa Filho, Dalton Muller

    2018-01-01

    The relationship between muscle strength and bone mineral content (BMC) and bone mineral density (BMD) is supposed from the assumption of the mechanical stress influence on bone tissue metabolism. However, the direct relationship is not well established in younger men, since the enhancement of force able to produce effective changes in bone health, still needs to be further studied. This study aimed to analyze the influence of muscle strength on BMC and BMD in undergraduate students. Thirty six men (24.9 ± 8.6 y/o) were evaluated for regional and whole-body composition by dual energy X-ray absorptiometry (DXA). One repetition maximum tests (1RM) were assessed on flat bench-press (BP), lat-pull down (LPD), leg-curl (LC), knee extension (KE), and leg-press 45° (LP45) exercises. Linear regression modelled the relationships of BMD and BMC to the regional body composition and 1RM values. Measurements of dispersion and error (R2adj and standard error of estimate (SEE)) were tested, setting ρ at ≤0.05. The BMD mean value for whole-body was 1.12±0.09 g/cm2 and BMC attained 2477.9 ± 379.2 g. The regional lean mass (LM) in upper-limbs (UL) (= 6.80±1.21 kg) was related to BMC and BMD for UL (R2adj = 0.74, pBMC and BMD for LL (R2adj = 0.68, pBMC (R2adj = 0.47, pBMC (R2adj = 0.36, pBMC and BMD in young men, strengthening the relationship between force and LM, and suggesting both to parametrizes bone mineral health.

  5. Does Skeletal Muscle Mass Influence Breast Cancer? Evaluating Mammary Tumorigenesis and Progression Genetically Hyper-Muscular Mice

    National Research Council Canada - National Science Library

    Zimmers, Teresa

    2006-01-01

    .... Mice lacking the skeletal muscle-specific muscle growth inhibitor myostatin and mice expressing a dominant negative form of the myostatin receptor, Activin Receptor Type IIB, display heightened muscle mass...

  6. The Influence of Body Mass Index, Sex, & Muscle Activation on Pressure Distribution During Lateral Falls on the Hip.

    Science.gov (United States)

    Pretty, Steven P; Martel, Daniel R; Laing, Andrew C

    2017-12-01

    Hip fracture incidence rates are influenced by body mass index (BMI) and sex, likely through mechanistic pathways that influence dynamics of the pelvis-femur system during fall-related impacts. The goal of this study was to extend our understanding of these impact dynamics by investigating the effects of BMI, sex, and local muscle activation on pressure distribution over the hip region during lateral impacts. Twenty participants underwent "pelvis-release experiments" (which simulate a lateral fall onto the hip), including muscle-'relaxed' and 'contracted' trials. Males and low-BMI individuals exhibited 44 and 55% greater peak pressure, as well as 66 and 56% lower peripheral hip force, compared to females and high-BMI individuals, respectively. Local muscle activation increased peak force by 10%, contact area by 17%, and peripheral hip force by 11% compared to relaxed trials. In summary, males and low-BMI individuals exhibited more concentrated loading over the greater trochanter. Muscle activation increased peak force, but this force was distributed over a larger area, preventing increased localized loading over the greater trochanter. These findings suggest potential value in incorporating sex, gender, and muscle activation-specific force distributions as inputs into computational tissue-level models, and have implications for the design of personalized protective devices including wearable hip protectors.

  7. Does Skeletal Muscle Mass Influence Breast Cancer? Evaluating Mammary Tumorigenesis and Progression Genetically Hyper-Muscular Mice

    Science.gov (United States)

    2006-07-01

    the skeletal muscle-specific muscle growth inhibitor myostatin and mice expressing a dominant negative form of the myostatin receptor, Activin...and rates of breast cancer initiation and progression. 15. SUBJECT TERMS Breast cancer, skeletal muscle, myostatin , MPA, DMBA, Activin receptor 16...including interleukins, Insulin-like Growth Factor (IGF) isoforms, IGF-binding proteins and myostatin . To determine the effect of skeletal muscle mass

  8. Influence of blood flow occlusion on the development of peripheral and central fatigue during small muscle mass handgrip exercise.

    Science.gov (United States)

    Broxterman, R M; Craig, J C; Smith, J R; Wilcox, S L; Jia, C; Warren, S; Barstow, T J

    2015-09-01

    Critical power represents an important threshold for neuromuscular fatigue development and may, therefore, dictate intensities for which exercise tolerance is determined by the magnitude of fatigue accrued. Peripheral fatigue appears to be constant across O2 delivery conditions for large muscle mass exercise, but this consistency is equivocal for smaller muscle mass exercise. We sought to determine the influence of blood flow occlusion during handgrip exercise on neuromuscular fatigue development and to examine the relationship between neuromuscular fatigue development and W '. Blood flow occlusion influenced the development of both peripheral and central fatigue, thus providing further evidence that the magnitude of peripheral fatigue is not constant across O2 delivery conditions for small muscle mass exercise. W ' appears to be related to the magnitude of fatigue accrued during exercise, which may explain the reported consistency of intramuscular metabolic perturbations and work performed for severe-intensity exercise. The influence of the muscle metabolic milieu on peripheral and central fatigue is currently unclear. Moreover, the relationships between peripheral and central fatigue and the curvature constant (W ') have not been investigated. Six men (age: 25 ± 4 years, body mass: 82 ± 10 kg, height: 179 ± 4 cm) completed four constant power handgrip tests to exhaustion under conditions of control exercise (Con), blood flow occlusion exercise (Occ), Con with 5 min post-exercise blood flow occlusion (Con + Occ), and Occ with 5 min post-exercise blood flow occlusion (Occ + Occ). Neuromuscular fatigue measurements and W ' were obtained for each subject. Each trial resulted in significant peripheral and central fatigue. Significantly greater peripheral (79.7 ± 5.1% vs. 22.7 ± 6.0%) and central (42.6 ± 3.9% vs. 4.9 ± 2.0%) fatigue occurred for Occ than for Con. In addition, significantly greater peripheral (83.0 ± 4.2% vs. 69.0 ± 6.2%) and central

  9. Influence of step-height and body mass on gastrocnemius muscle fascicle behavior during stair ascent.

    NARCIS (Netherlands)

    Spanjaard, M.; Reeves, N.D.; van Dieen, J.H.; Baltzopoulos, V.; Maganaris, C.N.

    2008-01-01

    To better understand the role of the ankle plantar flexor muscles in stair negotiation, we examined the effects of manipulation of kinematic and kinetic constraints on the behavior of the gastrocnemius medialis (GM) muscle during stair ascent. Ten subjects ascended a four-step staircase at four

  10. LOW MID-UPPER ARM CIRCUMFERENCE AND MORTALITY IN OLDER PERSONS: THE INFLUENCE OF FAT AND MUSCLE MASS

    NARCIS (Netherlands)

    Delmonico, M.J.; Harris, T.B.; Visser, M.; Park, S.W.; Conroy, M.B.; Velasquez-Mieyer, P.; Boudreau, R.; Manini, T.M.; Nevitt, M.; Newman, A.B.; Goodpaster, B.H.

    2009-01-01

    Background: Sarcopenia is thought to be accompanied by increased muscle fat infiltration. However, no longitudinal studies have examined concomitant changes in muscle mass, strength, or fat infiltration in older adults. Objective: We present longitudinal data on age-related changes in leg

  11. Influence of amino acids, dietary protein, and physical activity on muscle mass development in humans

    DEFF Research Database (Denmark)

    Dideriksen, Kasper; Reitelseder, Søren; Holm, Lars

    2013-01-01

    intake. Ingestion of excess protein exerts an unwanted load to the body and therefore, it is important to find the least amount of protein that provides the maximal hypertrophic stimulus. Hence, research has focused on revealing the relationship between protein intake (dose) and its resulting stimulation...... response dependent on the characteristics of the protein ingested. The effect of protein intake on muscle protein accretion can further be stimulated by prior exercise training. In the ageing population, physical training may counteract the development of "anabolic resistance" and restore the beneficial...

  12. Nutritional interventions to preserve skeletal muscle mass

    NARCIS (Netherlands)

    Backx, Evelien M.P.

    2016-01-01

    Muscle mass is the main predictor for muscle strength and physical function. The amount of muscle mass can decline rapidly during periods of reduced physical activity or during periods of energy intake restriction. For athletes, it is important to maintain muscle mass, since the loss of muscle is

  13. Influence of muscle strength, physical activity and weight on bone mass in a population-based sample of 1004 elderly women.

    Science.gov (United States)

    Gerdhem, P; Ringsberg, K A M; Akesson, K; Obrant, K J

    2003-09-01

    High physical activity level has been associated with high bone mass and low fracture risk and is therefore recommended to reduce fractures in old age. The aim of this study was to estimate the effect of potentially modifiable variables, such as physical activity, muscle strength, muscle mass and weight, on bone mass in elderly women. The influence of isometric thigh muscle strength, self-estimated activity level, body composition and weight on bone mineral density (dual energy X-ray absorptiometry; DXA) in total body, hip and spine was investigated. Subjects were 1004 women, all 75 years old, taking part in the Malmö Osteoporosis Prospective Risk Assessment (OPRA) study. Physical activity and muscle strength accounted for 1-6% of the variability in bone mass, whereas weight, and its closely associated variables lean mass and fat mass, to a much greater extent explained the bone mass variability. We found current body weight to be the variable with the most substantial influence on the total variability in bone mass (15-32% depending on skeletal site) in a forward stepwise regression model. Our findings suggest that in elderly women, the major fracture-preventive effect of physical activity is unlikely to be mediated through increased bone mass. Retaining or even increasing body weight is likely to be beneficial to the skeleton, but an excess body weight increase may have negative effects on health. Nevertheless, training in elderly women may have advantages by improving balance, co-ordination and mobility and therefore decreasing the risk of fractures.

  14. Muscle Mass and Weight Gain Nutritional Supplements

    Science.gov (United States)

    Campbell, Bill

    There are numerous sports supplements available that claim to increase lean body mass. However, for these sports supplements to exert any favorable changes in lean body mass, they must influence those factors regulating skeletal muscle hypertrophy (i.e., satellite cell activity, gene transcription, protein translation). If a given sports supplement does favorably influence one of these regulatory factors, the result is a positive net protein balance (in which protein synthesis exceeds protein breakdown). Sports supplement categories aimed at eliciting a positive net protein balance include anabolic hormone enhancers, nutrient timing pre- and postexercise workout supplements, anticatabolic supplements, and nitric oxide boosters. Of all the sports supplements available, only a few have been subject to multiple clinical trials with repeated favorable outcomes relative to increasing lean body mass. This chapter focuses on these supplements and others that have a sound theoretical rationale in relation to increasing lean body mass.

  15. Influence of combined resistance training and healthy diet on muscle mass in healthy elderly women: a randomized controlled trial.

    Science.gov (United States)

    Strandberg, Emelie; Edholm, Peter; Ponsot, Elodie; Wåhlin-Larsson, Britta; Hellmén, Erik; Nilsson, Andreas; Engfeldt, Peter; Cederholm, Tommy; Risérus, Ulf; Kadi, Fawzi

    2015-10-15

    The delivery of efficient nonpharmacological treatment to prevent the loss of muscle mass in older adults is a major challenge, and information on the combined effects of training and diet is particularly important. Here we aimed to evaluate the effects of 24 wk of resistance training combined with a healthy dietary approach (n-6/n-3 ratio healthy and physically active older women (65-70 years). The three-armed randomized controlled trial included a resistance training + healthy diet group (RT-HD), a resistance training group (RT), and controls (CON). All subjects included in the study were physically active and had low levels of serum inflammatory markers. In accordance with the dietary goals, the n-6/n-3 ratio dietary intake significantly decreased only in RT-HD by 42%. An increase in 1 repetition maximum in leg extension occurred in RT (+20.4%) and RT-HD (+20.8%), but not in CON. Interestingly, leg lean mass significantly increased only in RT-HD (+1.8%). While there were no changes in serum C-reactive protein and IL-6 levels, a significant decrease in serum level of the pro-inflammatory precursor arachidonic acid (-5.3 ± 9.4%) together with an increase in serum n-3 docosahexaenoic acid (+8.3%) occurred only in RT-HD. Altogether, this study demonstrates that the effects of resistance training on muscle mass in healthy older adults can be optimized by the adoption of a healthy diet. Copyright © 2015 the American Physiological Society.

  16. CORRELATIONS BETWEEN MUSCLE MASS, MUSCLE STRENGTH, PHYSICAL PERFORMANCE, AND MUSCLE FATIGUE RESISTANCE IN COMMUNITY-DWELLING ELDERLY SUBJECTS

    Directory of Open Access Journals (Sweden)

    Elizabeth

    2016-03-01

    Full Text Available Objective: To determine the correlations between muscle mass, muscle strength, physical performance, and muscle fatigue resistance in community-dwelling elderly people in order to elucidate factors which contribute to elderly’s performance of daily activities. Methods: A cross-sectional study was conducted on community-dwelling elderly in Bandung from September to December 2014. One hundred and thirty elderly, 60 years old or above, were evaluated using bioelectrical impedance analysis to measure muscle mass; grip strength to measure muscle strength and muscle fatigue resistance; habitual gait speed to measure physical performance; and Global Physical Activity Questionnaire (GPAQ to assess physical activity. Results: There were significant positive correlations between muscle mass (r=0,27, p=0,0019, muscle strength (r=0,26, p=0,0024, and physical performance (r=0,32, p=0,0002 with muscle fatigue resistance. Physical performance has the highest correlation based on multiple regression test (p=0,0025. In association with muscle mass, the physical activity showed a significant positive correlation (r=0,42, p=0,0000. Sarcopenia was identified in 19 (14.61% of 130 subjects. Conclusions: It is suggested that muscle mass, muscle strength, and physical performance influence muscle fatigue resistance.

  17. Low Muscle Mass and Breast Cancer Survival

    Science.gov (United States)

    In a new study, researchers compared the risk of death for women with breast cancer who had low skeletal muscle mass, or sarcopenia, at diagnosis and women who had adequate muscle mass. Learn what they found and what it might mean for patients in this Cancer Currents blog post.

  18. Does Skeletal Muscle Mass Influence Breast Cancer? Evaluating Mammary Tumorigenesis and Progression in Genetically Hyper-Muscular Mice

    Science.gov (United States)

    2007-07-01

    muscle growth inhibitor myostatin and mice expressing a dominant negative form of the myostatin receptor (MLC-dnActRIIB mice). Mammary cancer was...hypermuscular mice and the results are pending. In the interim we used genetic and pharmacological inhibition of the myostatin pathway to potentially...metabolic syndrome induced by the tumor. However, despite increasing normal muscle growth, myostatin inhibition failed to protect mice from cancer

  19. Assessment of the influence of body composition on bone mass in children and adolescents based on a functional analysis of the muscle-bone relationship.

    Science.gov (United States)

    Golec, Joanna; Chlebna-Sokół, Danuta

    2014-01-01

    The functional model of skeletal development considers the mechanical factor to be the most important skeletal modulant. The aim of the study was a functional analysis of the bone-muscle relationship in children with low and normal bone mass. The study involved 149 children with low and 99 children with normal bone mass (control group). All patients underwent a densitometry examination (DXA). Low bone mass was diagnosed if the Z-score was below values of Z-scores for all parameters in children with low bone mass as compared to the control group. Children with low bone mass had lower content of adipose and muscle tissue and a marked deficit of muscle tissue with regard to height (which according to mechanostat theory leads to lower muscle-generated strain on bones). This group of children had also lower TBBMC/LBM Z-scores, which indicates greater fracture susceptibility. 1. Functional analysis, which showed associations between bone and muscle tissues, can be useful for diagnosing and monitoring skeletal system disorders as well as making therapeutic decisions.2. The study emphasizes the role of proper nutrition and physical activities, which contribute to proper body composition, in the prevention of bone mineralization disorders in childhood and adolescence. 3. The study showed the inadequacy of the classic reference ranges used in interpreting DXA data in children and demonstrated the usefulness of continuous variables for that purpose.

  20. Influence of Nordic Walking Training on Muscle Strength and the Electromyographic Activity of the Lower Body in Women With Low Bone Mass

    Directory of Open Access Journals (Sweden)

    Ossowski Zbigniew

    2016-06-01

    Full Text Available Introduction. Osteoporosis and osteopenia are related to changes in the quantity and quality of skeletal muscle and contribute to a decreased level of muscle strength. The purpose of this study was to evaluate the impact of Nordic walking training on muscle strength and the electromyographic (EMG activity of the lower body in women with low bone mass. Material and methods. The participants of the study were 27 women with low bone mass. The sample was randomly divided into two groups: a control group and an experimental group. Women from the experimental group participated in 12 weeks of regular Nordic walking training. Functional strength was assessed with a 30-second chair stand test. The EMG activities of the gluteus maximus (GMax, rectus femoris (RF, biceps femoris (BF, soleus (SOL, and lumbar (LB muscles were measured using a surface electromyogram. Results. Nordic walking training induced a significant increase in the functional strength (p = 0.006 of the lower body and activity of GMax (p = 0.013 and a decrease in body mass (p = 0.006 in women with reduced bone mass. There was no statistically significant increase in the EMG activities of the RF, BF, SOL, or LB muscles. The study did not indicate any significant changes in functional muscle strength, the EMG activity of the lower body, or anthropometry in women from the control group. Conclusions. Nordic walking training induces positive changes in lower body strength and the electromyographic activity of the gluteus maximus as well as a decrease in body mass in women with low bone mass.

  1. Muscle strength rather than muscle mass is associated with osteoporosis in older Chinese adults

    Directory of Open Access Journals (Sweden)

    Yixuan Ma

    2018-02-01

    Conclusion: Based on our study, muscle strength rather than muscle mass is negatively associated with OS in older people; thus, we should pay more attention to muscle strength training in the early stage of the OS.

  2. Influence of aging on isometric muscle strength, fat-free mass and electromyographic signal power of the upper and lower limbs in women

    Science.gov (United States)

    Amaral, Josária F.; Alvim, Felipe C.; Castro, Eliane A.; Doimo, Leonice A.; Silva, Marcus V.; Novo, José M.

    2014-01-01

    Background Aging is a multifactorial process that leads to changes in the quantity and quality of skeletal muscle and contributes to decreased levels of muscle strength. Objective This study sought to investigate whether the isometric muscle strength, fat-free mass (FFM) and power of the electromyographic (EMG) signal of the upper and lower limbs of women are similarly affected by aging. Method The sample consisted of 63 women, who were subdivided into three groups (young (YO) n=33, 24.7±3.5 years; middle age (MA) n=15, 58.6±4.2 years; and older adults (OA). n=15, 72.0±4.2 years). Isometric strength was recorded simultaneously with the capture of the electrical activity of the flexor muscles of the fingers and the vastus lateralis during handgrip and knee extension tests, respectively. FFM was assessed using dual-energy X-ray absorptiometry. Results The handgrip strength measurements were similar among groups (p=0.523), whereas the FFM of the upper limbs was lower in group OA compared to group YO (p=0.108). The RMSn values of the hand flexors were similar among groups (p=0.754). However, the strength of the knee extensors, the FFM of the lower limbs and the RMSn values of the vastus lateralis were lower in groups MA (p=0.014, p=0.006 and p=0.013, respectively) and OA (p=0.000, p=0.000 and pisometric muscle strength in MLG and electromyographic activity of the lower limbs are more pronounced with the aging process of the upper limb. PMID:24676705

  3. Double standards in body evaluation? The influence of identification with body stimuli on ratings of attractiveness, body fat, and muscle mass.

    Science.gov (United States)

    Voges, Mona M; Giabbiconi, Claire-Marie; Schöne, Benjamin; Waldorf, Manuel; Hartmann, Andrea S; Vocks, Silja

    2017-10-20

    Although it is well documented that women evaluate their own body differently from other bodies, it remains unclear whether this discrepancy is based on double standards because of identity or on objective differences between these bodies. The aim of this study was therefore to test whether women apply double standards depending on a body's identity when evaluating the same bodies presented with different faces. Average-weight women (N = 104) rated body attractiveness, body fat, and muscle mass of thin, average-weight, overweight, athletic, and hypermuscular bodies with either another female's face or their own face. With their own face, subjects rated overweight bodies as more unattractive, higher in body fat and lower in muscle mass than with another female's face. However, for non-overweight bodies, body ratings did not differ depending on body identity. Based on the self-deprecating double standards for overweight bodies, a body-related identity bias might be considered in theoretical models of body image. Level of evidence Level V, descriptive study.

  4. Integrated expression analysis of muscle hypertrophy identifies Asb2 as a negative regulator of muscle mass

    Science.gov (United States)

    Davey, Jonathan R.; Watt, Kevin I.; Parker, Benjamin L.; Chaudhuri, Rima; Ryall, James G.; Cunningham, Louise; Qian, Hongwei; Sartorelli, Vittorio; Chamberlain, Jeffrey; James, David E.

    2016-01-01

    The transforming growth factor-β (TGF-β) signaling network is a critical regulator of skeletal muscle mass and function and, thus, is an attractive therapeutic target for combating muscle disease, but the underlying mechanisms of action remain undetermined. We report that follistatin-based interventions (which modulate TGF-β network activity) can promote muscle hypertrophy that ameliorates aging-associated muscle wasting. However, the muscles of old sarcopenic mice demonstrate reduced response to follistatin compared with healthy young-adult musculature. Quantitative proteomic and transcriptomic analyses of young-adult muscles identified a transcription/translation signature elicited by follistatin exposure, which included repression of ankyrin repeat and SOCS box protein 2 (Asb2). Increasing expression of ASB2 reduced muscle mass, thereby demonstrating that Asb2 is a TGF-β network–responsive negative regulator of muscle mass. In contrast to young-adult muscles, sarcopenic muscles do not exhibit reduced ASB2 abundance with follistatin exposure. Moreover, preventing repression of ASB2 in young-adult muscles diminished follistatin-induced muscle hypertrophy. These findings provide insight into the program of transcription and translation events governing follistatin-mediated adaptation of skeletal muscle attributes and identify Asb2 as a regulator of muscle mass implicated in the potential mechanistic dysfunction between follistatin-mediated muscle growth in young and old muscles. PMID:27182554

  5. Muscle Strength and Muscle Mass in Older Patients during Hospitalization: The EMPOWER Study

    Science.gov (United States)

    Van Ancum, Jeanine M.; Scheerman, Kira; Pierik, Vincent D.; Numans, Siger T.; Verlaan, Sjors; Smeenk, Hanne E.; Slee-Valentijn, Monique; Kruizinga, Roeliene C.; Meskers, Carel G.M.; Maier, Andrea B.

    2017-01-01

    Background Low muscle strength and muscle mass are associated with an increased length of hospital stay and higher mortality rate in inpatients. To what extent hospitalization affects muscle strength and muscle mass is unclear. Objective We aimed to assess muscle strength and muscle mass at admission and during hospitalization in older patients and its relation with being at risk of geriatric conditions. Methods The EMPOWER study included patients aged 70 years and older, admitted to 4 wards of the VU University Medical Center in the Netherlands between April and December 2015. At admission, patients were screened for being at risk of 4 geriatric conditions: delirium, falls, malnutrition, and functional disability. At admission and at discharge, muscle strength and muscle mass were assessed. Results A total of 373 patients (mean age, standard deviation [SD]: 79.6, 6.38 years) were included at admission, and 224 patients (mean age, SD: 80.1, 6.32 years) at discharge. At admission, lower muscle strength in both female and male patients and low muscle mass in male patients were associated with being at risk of a higher cumulative number of geriatric conditions. Muscle strength increased during hospitalization, but no change in muscle mass was observed. Changes in muscle measures were not associated with being at risk of geriatric conditions. Discussion Older patients with lower muscle strength and muscle mass at admission were at risk of a higher cumulative number of geriatric conditions. However, being at risk of geriatric conditions did not forecast further decrease in muscle strength and muscle mass during hospitalization PMID:28817825

  6. Chronic exercise preserves lean muscle mass in masters athletes.

    Science.gov (United States)

    Wroblewski, Andrew P; Amati, Francesca; Smiley, Mark A; Goodpaster, Bret; Wright, Vonda

    2011-09-01

    Aging is commonly associated with a loss of muscle mass and strength, resulting in falls, functional decline, and the subjective feeling of weakness. Exercise modulates the morbidities of muscle aging. Most studies, however, have examined muscle-loss changes in sedentary aging adults. This leaves the question of whether the changes that are commonly associated with muscle aging reflect the true physiology of muscle aging or whether they reflect disuse atrophy. This study evaluated whether high levels of chronic exercise prevents the loss of lean muscle mass and strength experienced in sedentary aging adults. A cross-section of 40 high-level recreational athletes ("masters athletes") who were aged 40 to 81 years and trained 4 to 5 times per week underwent tests of health/activity, body composition, quadriceps peak torque (PT), and magnetic resonance imaging of bilateral quadriceps. Mid-thigh muscle area, quadriceps area (QA), subcutaneous adipose tissue, and intramuscular adipose tissue were quantified in magnetic resonance imaging using medical image processing, analysis, and visualization software. One-way analysis of variance was used to examine age group differences. Relationships were evaluated using Spearman correlations. Mid-thigh muscle area (P = 0.31) and lean mass (P = 0.15) did not increase with age and were significantly related to retention of mid-thigh muscle area (P lean mass (P = 0.4) and PT. This study contradicts the common observation that muscle mass and strength decline as a function of aging alone. Instead, these declines may signal the effect of chronic disuse rather than muscle aging. Evaluation of masters athletes removes disuse as a confounding variable in the study of lower-extremity function and loss of lean muscle mass. This maintenance of muscle mass and strength may decrease or eliminate the falls, functional decline, and loss of independence that are commonly seen in aging adults.

  7. Influence of muscle geometry on shortening speed of fibre, aponeurosis and muscle

    NARCIS (Netherlands)

    Zuurbier, C. J.; Huijing, P. A.

    1992-01-01

    The influence of muscle geometry on muscle shortening of the gastrocnemius medialis muscle (GM) of the rat was studied. Using cinematography, GM geometry was studied during isokinetic concentric activity at muscle lengths ranging from 85 to 105% of the optimum muscle length. The shortening speed of

  8. Effect of transcutaneous electrical muscle stimulation on postoperative muscle mass and protein synthesis

    DEFF Research Database (Denmark)

    Vinge, O; Edvardsen, L; Jensen, F

    1996-01-01

    In an experimental study, 13 patients undergoing major elective abdominal surgery were given postoperative transcutaneous electrical muscle stimulation (TEMS) to the quadriceps femoris muscle on one leg; the opposite leg served as control. Changes in cross-sectional area (CSA) and muscle protein ...... protein synthesis and muscle mass after abdominal surgery and should be evaluated in other catabolic states with muscle wasting.......In an experimental study, 13 patients undergoing major elective abdominal surgery were given postoperative transcutaneous electrical muscle stimulation (TEMS) to the quadriceps femoris muscle on one leg; the opposite leg served as control. Changes in cross-sectional area (CSA) and muscle protein...... synthesis were assessed by computed tomography and ribosome analysis of percutaneous muscle biopsies before surgery and on the sixth postoperative day. The percentage of polyribosomes in the ribosome suspension decreased significantly (P

  9. Novel biomarkers of changes in muscle mass or muscle pathology

    DEFF Research Database (Denmark)

    Arvanitidis, Athanasios

    healthy individuals and patients with different myopathy diseases, describe the underlying mechanisms of muscle conditions and possibly putative response to an intervention. There were three different studies where biomarkers were applied in this thesis. Study I involved 51 myositis patients (28...

  10. Counteracting age-related loss of skeletal muscle mass

    DEFF Research Database (Denmark)

    Bechshøft, Rasmus; Reitelseder, Søren; Højfeldt, Grith

    2016-01-01

    Background Aging is associated with decreased muscle mass and functional capacity, which in turn decrease quality of life. The number of citizens over the age of 65 years in the Western world will increase by 50 % over the next four decades, and this demographic shift brings forth new challenges...... at both societal and individual levels. Only a few longitudinal studies have been reported, but whey protein supplementation seems to improve muscle mass and function, and its combination with heavy strength training appears even more effective. However, heavy resistance training may reduce adherence...... Intervention Study will generate scientific evidence and recommendations to counteract age-related loss of skeletal muscle mass in elderly individuals....

  11. Inflammatory markers and loss of muscle mass (sarcopenia) and strength

    NARCIS (Netherlands)

    Schaap, Laura A; Pluijm, Saskia M F; Deeg, Dorly J H; Visser, Marjolein

    PURPOSE: The objective of this study was to investigate whether high levels of serum interleukin (IL)-6, C-reactive protein (CRP), and alpha1-antichymotrypsin (ACT) were associated with the loss of muscle strength or muscle mass (sarcopenia) in older persons. SUBJECTS: The study included 986 men and

  12. Association between muscle mass and a single measurement of ...

    African Journals Online (AJOL)

    cause mortality significantly. It is strongly associated with the risk of heart attack, coronary artery disease, cardiovascular disease, stroke and liver disease. The relationship between muscle mass and a diagnosis of hypertension in a sample of ...

  13. Regulation of skeletal muscle oxidative capacity and muscle mass by SIRT3.

    Directory of Open Access Journals (Sweden)

    Ligen Lin

    Full Text Available We have previously reported that the expression of mitochondrial deacetylase SIRT3 is high in the slow oxidative muscle and that the expression of muscle SIRT3 level is increased by dietary restriction or exercise training. To explore the function of SIRT3 in skeletal muscle, we report here the establishment of a transgenic mouse model with muscle-specific expression of the murine SIRT3 short isoform (SIRT3M3. Calorimetry study revealed that the transgenic mice had increased energy expenditure and lower respiratory exchange rate (RER, indicating a shift towards lipid oxidation for fuel usage, compared to control mice. The transgenic mice exhibited better exercise performance on treadmills, running 45% further than control animals. Moreover, the transgenic mice displayed higher proportion of slow oxidative muscle fibers, with increased muscle AMPK activation and PPARδ expression, both of which are known regulators promoting type I muscle fiber specification. Surprisingly, transgenic expression of SIRT3M3 reduced muscle mass up to 30%, likely through an up-regulation of FOXO1 transcription factor and its downstream atrophy gene MuRF-1. In summary, these results suggest that SIRT3 regulates the formation of oxidative muscle fiber, improves muscle metabolic function, and reduces muscle mass, changes that mimic the effects of caloric restriction.

  14. TAK1 regulates skeletal muscle mass and mitochondrial function

    Science.gov (United States)

    Hindi, Sajedah M.; Sato, Shuichi; Xiong, Guangyan; Bohnert, Kyle R.; Gibb, Andrew A.; Gallot, Yann S.; McMillan, Joseph D.; Hill, Bradford G.

    2018-01-01

    Skeletal muscle mass is regulated by a complex array of signaling pathways. TGF-β–activated kinase 1 (TAK1) is an important signaling protein, which regulates context-dependent activation of multiple intracellular pathways. However, the role of TAK1 in the regulation of skeletal muscle mass remains unknown. Here, we report that inducible inactivation of TAK1 causes severe muscle wasting, leading to kyphosis, in both young and adult mice.. Inactivation of TAK1 inhibits protein synthesis and induces proteolysis, potentially through upregulating the activity of the ubiquitin-proteasome system and autophagy. Phosphorylation and enzymatic activity of AMPK are increased, whereas levels of phosphorylated mTOR and p38 MAPK are diminished upon inducible inactivation of TAK1 in skeletal muscle. In addition, targeted inactivation of TAK1 leads to the accumulation of dysfunctional mitochondria and oxidative stress in skeletal muscle of adult mice. Inhibition of TAK1 does not attenuate denervation-induced muscle wasting in adult mice. Finally, TAK1 activity is highly upregulated during overload-induced skeletal muscle growth, and inactivation of TAK1 prevents myofiber hypertrophy in response to functional overload. Overall, our study demonstrates that TAK1 is a key regulator of skeletal muscle mass and oxidative metabolism. PMID:29415881

  15. Increasing Muscle Mass Improves Vascular Function in Obese (db/db) Mice

    Science.gov (United States)

    Qiu, Shuiqing; Mintz, James D.; Salet, Christina D.; Han, Weihong; Giannis, Athanassios; Chen, Feng; Yu, Yanfang; Su, Yunchao; Fulton, David J.; Stepp, David W.

    2014-01-01

    Background A sedentary lifestyle is an independent risk factor for cardiovascular disease and exercise has been shown to ameliorate this risk. Inactivity is associated with a loss of muscle mass, which is also reversed with isometric exercise training. The relationship between muscle mass and vascular function is poorly defined. The aims of the current study were to determine whether increasing muscle mass by genetic deletion of myostatin, a negative regulator of muscle growth, can influence vascular function in mesenteric arteries from obese db/db mice. Methods and Results Myostatin expression was elevated in skeletal muscle of obese mice and associated with reduced muscle mass (30% to 50%). Myostatin deletion increased muscle mass in lean (40% to 60%) and obese (80% to 115%) mice through increased muscle fiber size (PMyostatin deletion decreased adipose tissue in lean mice, but not obese mice. Markers of insulin resistance and glucose tolerance were improved in obese myostatin knockout mice. Obese mice demonstrated an impaired endothelial vasodilation, compared to lean mice. This impairment was improved by superoxide dismutase mimic Tempol. Deletion of myostatin improved endothelial vasodilation in mesenteric arteries in obese, but not in lean, mice. This improvement was blunted by nitric oxide (NO) synthase inhibitor l‐NG‐nitroarginine methyl ester (l‐NAME). Prostacyclin (PGI2)‐ and endothelium‐derived hyperpolarizing factor (EDHF)‐mediated vasodilation were preserved in obese mice and unaffected by myostatin deletion. Reactive oxygen species) was elevated in the mesenteric endothelium of obese mice and down‐regulated by deletion of myostatin in obese mice. Impaired vasodilation in obese mice was improved by NADPH oxidase inhibitor (GKT136901). Treatment with sepiapterin, which increases levels of tetrahydrobiopterin, improved vasodilation in obese mice, an improvement blocked by l‐NAME. Conclusions Increasing muscle mass by genetic deletion of

  16. Relation between body mass index percentile and muscle strength ...

    African Journals Online (AJOL)

    Relation between body mass index percentile and muscle strength and endurance. ... Egyptian Journal of Medical Human Genetics ... They were divided into three groups according to their body mass index percentile where group (a) is equal to or more than 5% percentile yet less than 85% percentile, group (b) is equal to ...

  17. Skeletal muscle mass and exercise performance in stable ambulatory patients with heart failure.

    Science.gov (United States)

    Lang, C C; Chomsky, D B; Rayos, G; Yeoh, T K; Wilson, J R

    1997-01-01

    The purpose of this study was to determine whether skeletal muscle atrophy limits the maximal exercise capacity of stable ambulatory patients with heart failure. Body composition and maximal exercise capacity were measured in 100 stable ambulatory patients with heart failure. Body composition was assessed by using dual-energy X-ray absorption. Peak exercise oxygen consumption (VO2peak) and the anaerobic threshold were measured by using a Naughton treadmill protocol and a Medical Graphics CardioO2 System. VO2peak averaged 13.4 +/- 3.3 ml.min-1.kg-1 or 43 +/- 12% of normal. Lean body mass averaged 52.9 +/- 10.5 kg and leg lean mass 16.5 +/- 3.6 kg. Leg lean mass correlated linearly with VO2peak (r = 0.68, P < 0.01), suggesting that exercise performance is influences by skeletal muscle mass. However, lean body mass was comparable to levels noted in 1,584 normal control subjects, suggesting no decrease in muscle mass. Leg muscle mass was comparable to levels noted in 34 normal control subjects, further supporting this conclusion. These findings suggest that exercise intolerance in stable ambulatory patients with heart failure is not due to skeletal muscle atrophy.

  18. Correlation between Body Mass Index, Gender, and Skeletal Muscle Mass Cut off Point in Bandung

    OpenAIRE

    Richi Hendrik Wattimena; Vitriana; Irma Ruslina Defi

    2017-01-01

    Objective: To determine the average skeletal muscle mass (SMM) value in young adults as a reference population; to analyze the correlation of gender, and body mass index to the cut off point; and to determine skeletal muscle mass cut off points of population in Bandung, Indonesia. Methods: This was a cross-sectional study involving 199 participants, 122 females and 77 males. The sampling technique used was the multistage random sampling. The participants were those who lived in four ma...

  19. [Variation of muscle mass and weight in critical patient].

    Science.gov (United States)

    Valls-Matarín, J; del Cotillo-Fuente, M; Grané-Mascarell, N; Quintana, S

    2015-01-01

    Quantify the muscle mass and body weight variation in critically ill patients and to identify associated factors. A descriptive follow-up study. Data for demographic variables, body weight, fluid balance, daily kilocalories, the amount of sedation and muscle relaxants received and motor physiotherapy applied were collected. Three consecutive measurements were performed in the brachial biceps and quadriceps rectus by using ultrasound, upon admission and every 5 days until discharge. 68 patients were included. Average age was of 73.5 [57-78,5] years. The median length of stay was 9.5 [5.5 -15] days. The median 16 (SD=5.7) daily kilocalories per kg/weight, 91.2% received sedation, 44.1% received muscle relaxants and 20% received physiotherapy. The patients presented a muscle wasting of 4.9 (SD=3.9)mm, p <.001 in the brachial biceps and 5.6 (SD=4.8)mm, p <.001 in the quadriceps rectus. Regression analysis selected the length of stay and the muscle relaxants are the most influential variables in the brachial biceps muscle wasting (R2=0.4), and length of stay as the most influential in the quadriceps rectus muscle wasting (R2=0.3). Patient's mean body weight on admission was of 81.1 (SD=15)kg and 81.2 (SD=14.2)kg on discharge, p=.95. The critically ill patient presents a significant muscle waste related with the length of stay and the treatment received with muscle relaxants. Patients are being discharged with a similar body weight to which they were admitted but with a significant reduction of muscle mass. Copyright © 2014 Elsevier España, S.L.U. y SEEIUC. All rights reserved.

  20. Middle cerebral artery blood velocity depends on cardiac output during exercise with a large muscle mass

    NARCIS (Netherlands)

    Ide, K.; Pott, F.; van Lieshout, J. J.; Secher, N. H.

    1998-01-01

    We tested the hypothesis that pharmacological reduction of the increase in cardiac output during dynamic exercise with a large muscle mass would influence the cerebral blood velocity/perfusion. We studied the relationship between changes in cerebral blood velocity (transcranial Doppler), rectus

  1. Myoglobin plasma level related to muscle mass and fiber composition: a clinical marker of muscle wasting?

    Science.gov (United States)

    Weber, Marc-André; Kinscherf, Ralf; Krakowski-Roosen, Holger; Aulmann, Michael; Renk, Hanna; Künkele, Annette; Edler, Lutz; Kauczor, Hans-Ulrich; Hildebrandt, Wulf

    2007-08-01

    Progressive muscle wasting is a central feature of cancer-related cachexia and has been recognized as a determinant of poor prognosis and quality of life. However, until now, no easily assessable clinical marker exists that allows to predict or to track muscle wasting. The present study evaluated the potential of myoglobin (MG) plasma levels to indicate wasting of large locomotor muscles and, moreover, to reflect the loss of MG-rich fiber types, which are most relevant for daily performance. In 17 cancer-cachectic patients (weight loss 22%) and 27 age- and gender-matched healthy controls, we determined plasma levels of MG and creatine kinase (CK), maximal quadriceps muscle cross-sectional area (CSA) by magnetic resonance imaging, muscle morphology and fiber composition in biopsies from the vastus lateralis muscle, body cell mass (BCM) by impedance technique as well as maximal oxygen uptake (VO(2)max). In cachectic patients, plasma MG, muscle CSA, BCM, and VO(2)max were 30-35% below control levels. MG showed a significant positive correlation to total muscle CSA (r = 0.65, p max as an important functional readout. CK plasma levels appear to be less reliable because prolonged increases are observed in even subclinical myopathies or after exercise. Notably, cancer-related muscle wasting was not associated with increases in plasma MG or CK in this study.

  2. Correlates of increased lean muscle mass in women with polycystic ovary syndrome.

    Science.gov (United States)

    Carmina, E; Guastella, E; Longo, R A; Rini, G B; Lobo, R A

    2009-10-01

    Muscle mass plays an important role in determining cardiovascular and metabolic risks in polycystic ovary syndrome (PCOS). In addition, whether lean mass influences carotid intima-media thickness (IMT) in PCOS has not been assessed. Prospective investigation. Ninety-five women with PCOS were age- and weight-matched to 90 ovulatory controls. All women had dual X-ray absorptiometry for lean, fat and bone mass, and bone mass density (BMD). Serum testosterone, sex hormone-binding globulin, insulin, and glucose and carotid IMT were determined. Free androgen index (FAI) and insulin resistance (by QUICKI) were calculated. In PCOS, waist circumference and insulin were higher and QUICKI lower than in controls (Plean mass were higher in PCOS compared to controls (PPCOS (PPCOS patients had abnormal (> or = 0.9 mm) values. Lean mass correlated with fat parameters, insulin, QUICKI, and FAI, but not with total testosterone; and after adjustments for insulin and QUICKI, lean mass still correlated with fat mass (PLean mass correlated with IMT (Plean mass independently of insulin. Bone mass correlated with lean and fat mass, but not with insulin or androgen. PCOS patients with 'pathological' IMT values had higher % trunk fat, lean mass, and insulin, lower QUICKI, and higher testosterone and FAI compared with those with normal IMT. Lean mass is increased in PCOS, while bone mass is similar to that of matched controls. The major correlates of lean mass are fat mass and insulin but not androgen. Lean mass also correlated with IMT, and although influenced by insulin, small changes in IMT may partially reflect changes in muscle mass, while clearly abnormal values relate to more severe abnormalities of PCOS.

  3. Muscle hypertrophy: a narrative review on training principles for increasing muscle mass

    OpenAIRE

    Howe, Louis; Read, Paul; Waldron, Mark

    2017-01-01

    Developing muscle cross-sectional area has the potential to enhance performance for many athletes. Because emerging evidence challenges traditional beliefs regarding the prescription of hypertrophy-focused training programs, this review provides an overview of the current literature relating, specifically, to programming variables. Evidence-based recommendations are provided for the design of effective resistance-training programs, with the goal of increasing an athlete's skeletal muscle mass.

  4. Muscle mass as a target to reduce fatigue in patients with advanced cancer.

    Science.gov (United States)

    Neefjes, Elisabeth C W; van den Hurk, Renske M; Blauwhoff-Buskermolen, Susanne; van der Vorst, Maurice J D L; Becker-Commissaris, Annemarie; de van der Schueren, Marian A E; Buffart, Laurien M; Verheul, Henk M W

    2017-08-01

    Cancer-related fatigue (CRF) reduces quality of life and the activity level of patients with cancer. Cancer related fatigue can be reduced by exercise interventions that may concurrently increase muscle mass. We hypothesized that low muscle mass is directly related to higher CRF. A total of 233 patients with advanced cancer starting palliative chemotherapy for lung, colorectal, breast, or prostate cancer were studied. The skeletal muscle index (SMI) was calculated as the patient's muscle mass on level L3 or T4 of a computed tomography scan, adjusted for height. Fatigue was assessed with the Functional Assessment of Chronic Illness Therapy-fatigue questionnaire (cut-off for fatigue fatigue score was 36 (interquartile range 26-44). A higher SMI on level L3 was significantly associated with less CRF for men (B 0.447, P 0.004) but not for women (B - 0.401, P 0.090). No association between SMI on level T4 and the Functional Assessment of Chronic Illness Therapy-fatigue score was found (n = 82). The association between SMI and CRF may lead to the suggestion that male patients may be able to reduce fatigue by exercise interventions aiming at an increased muscle mass. In women with advanced cancer, CRF is more influenced by other causes, because it is not significantly related to muscle mass. To further reduce CRF in both men and women with cancer, multifactorial assessments need to be performed in order to develop effective treatment strategies. © 2017 The Authors. Journal of Cachexia, Sarcopenia and Muscle published by John Wiley & Sons Ltd on behalf of the Society on Sarcopenia, Cachexia and Wasting Disorders.

  5. The Regulation of Muscle Mass by Endogenous Glucocorticoids

    Directory of Open Access Journals (Sweden)

    Daniel L Marks

    2015-02-01

    Full Text Available Glucocorticoids are highly conserved fundamental regulators of energy homeostasis. In response to stress in the form of perceived danger or acute inflammation, glucocorticoids are released from the adrenal gland, rapidly mobilizing energy from carbohydrate, fat and protein stores. In the case of inflammation, mobilized protein is critical for the rapid synthesis of acute phase reactants and an efficient immune response to infection. While adaptive in response to infection, chronic mobilization can lead to a p rofound depletion of energy stores. Skeletal muscle represents the major body store of protein, and can become substantially atrophied under conditions of chronic inflammation. Glucocorticoids elicit the atrophy of muscle by increasing the rate of protein degradation by the ubiquitin-proteasome system and autophagy lysosome system. Protein synthesis is also suppressed at the level of translational initiation, preventing the production of new myofibrillar protein. Glucocorticoids also antagonize the action of anabolic regulators such as insulin further exacerbating the loss of protein and muscle mass. The loss of muscle mass in the context of chronic disease is a key feature of cachexia and contributes substantially to morbidity and mortality. A growing body of evidence demonstrates that glucocorticoid signaling is a common mediator of wasting, irrespective of the underlying initiator or disease state. This review will highlight fundamental mechanisms of glucocorticoid signaling and detail the mechanisms of glucocorticoid-induced muscle atrophy. Additionally, the evidence for glucocorticoids as a driver of muscle wasting in numerous disease states will be discussed. Given the burden of wasting diseases and the nodal nature of glucocorticoid signaling, effective anti-glucocorticoid therapy would be a valuable clinical tool. Therefore, the progress and potential pitfalls in the development of glucocorticoid antagonists for muscle wasting will

  6. Diagnostic ultrasound estimates of muscle mass and muscle quality discriminate between women with and without sarcopenia

    Directory of Open Access Journals (Sweden)

    Catheeja eIsmail

    2015-10-01

    Full Text Available Introduction: Age-related changes in muscle mass and muscle tissue composition contribute to diminished strength in older adults. The objectives of this study are to examine if an assessment method using mobile diagnostic ultrasound augments well-known determinants of lean body mass (LBM to aid sarcopenia staging, and if a sonographic measure of muscle quality is associated with muscle performance.Methods: Twenty community-dwelling female subjects participated in the study (age = 43.4 ±20.9 years; BMI: 23.8, interquartile range: 8.5. Dual energy X-ray absorptiometry (DXA and diagnostic ultrasound morphometry were used to estimate LBM. Muscle tissue quality was estimated via the echogenicity using grayscale histogram analysis. Peak force was measured with grip dynamometry and scaled for body size. Bivariate and multiple regression analyses were used to determine the association of the predictor variables with appendicular lean mass (aLM/ht2, and examine the relationship between scaled peak force values and muscle echogenicity. The sarcopenia LBM cut point value of 6.75 kg/m2 determined participant assignment into the Normal LBM and Low LBM subgroups.Results: The selected LBM predictor variables were body mass index (BMI, ultrasound morphometry, and age. Although BMI exhibited a significant positive relationship with aLM/ht2 (adj. R2 = .61, p < .001, the strength of association improved with the addition of ultrasound morphometry and age as predictor variables (adj. R2 = .85, p < .001. Scaled peak force was associated with age and echogenicity (adj. R2 = .53, p < .001, but not LBM. The Low LBM subgroup of women (n = 10 had higher scaled peak force, lower BMI, and lower echogenicity values in comparison to the Normal LBM subgroup (n = 10; p < .05.Conclusions: Diagnostic ultrasound morphometry values are associated with LBM, and improve the BMI predictive model for aLM/ht2 in women. In addition, ultrasound proxy measures of muscle quality are more

  7. The adipokine leptin increases skeletal muscle mass and significantly alters skeletal muscle miRNA expression profile in aged mice

    International Nuclear Information System (INIS)

    Hamrick, Mark W.; Herberg, Samuel; Arounleut, Phonepasong; He, Hong-Zhi; Shiver, Austin; Qi, Rui-Qun; Zhou, Li; Isales, Carlos M.

    2010-01-01

    Research highlights: → Aging is associated with muscle atrophy and loss of muscle mass, known as the sarcopenia of aging. → We demonstrate that age-related muscle atrophy is associated with marked changes in miRNA expression in muscle. → Treating aged mice with the adipokine leptin significantly increased muscle mass and the expression of miRNAs involved in muscle repair. → Recombinant leptin therapy may therefore be a novel approach for treating age-related muscle atrophy. -- Abstract: Age-associated loss of muscle mass, or sarcopenia, contributes directly to frailty and an increased risk of falls and fractures among the elderly. Aged mice and elderly adults both show decreased muscle mass as well as relatively low levels of the fat-derived hormone leptin. Here we demonstrate that loss of muscle mass and myofiber size with aging in mice is associated with significant changes in the expression of specific miRNAs. Aging altered the expression of 57 miRNAs in mouse skeletal muscle, and many of these miRNAs are now reported to be associated specifically with age-related muscle atrophy. These include miR-221, previously identified in studies of myogenesis and muscle development as playing a role in the proliferation and terminal differentiation of myogenic precursors. We also treated aged mice with recombinant leptin, to determine whether leptin therapy could improve muscle mass and alter the miRNA expression profile of aging skeletal muscle. Leptin treatment significantly increased hindlimb muscle mass and extensor digitorum longus fiber size in aged mice. Furthermore, the expression of 37 miRNAs was altered in muscles of leptin-treated mice. In particular, leptin treatment increased the expression of miR-31 and miR-223, miRNAs known to be elevated during muscle regeneration and repair. These findings suggest that aging in skeletal muscle is associated with marked changes in the expression of specific miRNAs, and that nutrient-related hormones such as leptin

  8. The adipokine leptin increases skeletal muscle mass and significantly alters skeletal muscle miRNA expression profile in aged mice

    Energy Technology Data Exchange (ETDEWEB)

    Hamrick, Mark W., E-mail: mhamrick@mail.mcg.edu [Department of Cellular Biology and Anatomy, Institute of Molecular Medicine and Genetics, Medical College of Georgia, Augusta, GA (United States); Department of Orthopaedic Surgery, Institute of Molecular Medicine and Genetics, Medical College of Georgia, Augusta, GA (United States); Herberg, Samuel; Arounleut, Phonepasong [Department of Cellular Biology and Anatomy, Institute of Molecular Medicine and Genetics, Medical College of Georgia, Augusta, GA (United States); Department of Orthopaedic Surgery, Institute of Molecular Medicine and Genetics, Medical College of Georgia, Augusta, GA (United States); He, Hong-Zhi [Henry Ford Immunology Program, Henry Ford Health System, Detroit, MI (United States); Department of Dermatology, Henry Ford Health System, Detroit, MI (United States); Shiver, Austin [Department of Cellular Biology and Anatomy, Institute of Molecular Medicine and Genetics, Medical College of Georgia, Augusta, GA (United States); Department of Orthopaedic Surgery, Institute of Molecular Medicine and Genetics, Medical College of Georgia, Augusta, GA (United States); Qi, Rui-Qun [Henry Ford Immunology Program, Henry Ford Health System, Detroit, MI (United States); Department of Dermatology, Henry Ford Health System, Detroit, MI (United States); Zhou, Li [Henry Ford Immunology Program, Henry Ford Health System, Detroit, MI (United States); Department of Dermatology, Henry Ford Health System, Detroit, MI (United States); Department of Internal Medicine, Henry Ford Health System, Detroit, MI (United States); Isales, Carlos M. [Department of Cellular Biology and Anatomy, Institute of Molecular Medicine and Genetics, Medical College of Georgia, Augusta, GA (United States); Department of Orthopaedic Surgery, Institute of Molecular Medicine and Genetics, Medical College of Georgia, Augusta, GA (United States); others, and

    2010-09-24

    Research highlights: {yields} Aging is associated with muscle atrophy and loss of muscle mass, known as the sarcopenia of aging. {yields} We demonstrate that age-related muscle atrophy is associated with marked changes in miRNA expression in muscle. {yields} Treating aged mice with the adipokine leptin significantly increased muscle mass and the expression of miRNAs involved in muscle repair. {yields} Recombinant leptin therapy may therefore be a novel approach for treating age-related muscle atrophy. -- Abstract: Age-associated loss of muscle mass, or sarcopenia, contributes directly to frailty and an increased risk of falls and fractures among the elderly. Aged mice and elderly adults both show decreased muscle mass as well as relatively low levels of the fat-derived hormone leptin. Here we demonstrate that loss of muscle mass and myofiber size with aging in mice is associated with significant changes in the expression of specific miRNAs. Aging altered the expression of 57 miRNAs in mouse skeletal muscle, and many of these miRNAs are now reported to be associated specifically with age-related muscle atrophy. These include miR-221, previously identified in studies of myogenesis and muscle development as playing a role in the proliferation and terminal differentiation of myogenic precursors. We also treated aged mice with recombinant leptin, to determine whether leptin therapy could improve muscle mass and alter the miRNA expression profile of aging skeletal muscle. Leptin treatment significantly increased hindlimb muscle mass and extensor digitorum longus fiber size in aged mice. Furthermore, the expression of 37 miRNAs was altered in muscles of leptin-treated mice. In particular, leptin treatment increased the expression of miR-31 and miR-223, miRNAs known to be elevated during muscle regeneration and repair. These findings suggest that aging in skeletal muscle is associated with marked changes in the expression of specific miRNAs, and that nutrient

  9. The influence of experimentally induced pain on shoulder muscle activity

    DEFF Research Database (Denmark)

    Diederichsen, L.P.; Winther, A.; Dyhre-Poulsen, P.

    2009-01-01

    healthy men (range 22-27 years), with no history of shoulder or cervical problems, were included in the study. Pain was induced by 5% hypertonic saline injections into the supraspinatus muscle or subacromially. Seated in a shoulder machine, subjects performed standardized concentric abduction (0A degrees......Muscle function is altered in painful shoulder conditions. However, the influence of shoulder pain on muscle coordination of the shoulder has not been fully clarified. The aim of the present study was to examine the effect of experimentally induced shoulder pain on shoulder muscle function. Eleven...... muscles. EMG was recorded before pain, during pain and after pain had subsided and pain intensity was continuously scored on a visual analog scale (VAS). During abduction, experimentally induced pain in the supraspinatus muscle caused a significant decrease in activity of the anterior deltoid, upper...

  10. Appendicular Skeletal Muscle Mass Reference Values and the Peak Muscle Mass to Identify Sarcopenia among Iranian Healthy Population.

    Science.gov (United States)

    Shafiee, Gita; Ostovar, Afshin; Heshmat, Ramin; Keshtkar, Abbas Ali; Sharifi, Farshad; Shadman, Zhaleh; Nabipour, Iraj; Soltani, Akbar; Larijani, Bagher

    2018-01-01

    Sacopenia is a common problem in elderly with the adverse outcomes. The objective of this study was to estimate the peak appendicular skeletal muscle mass (ASM) and age of its attainment by sex among the Iranian population. A total of 691 men and women aged 18-94 years participated in this cross-sectional, population-based study in Bushehr, Iran. ASM was measured by dual X-ray absorptiometry. Cutoff points for men and women were established considering two standard deviations (SDs) below the mean values of the skeletal muscle index (SMI) for young reference groups. The relationship between ASM and age was described by the second-degree regression models. Two SDs below the mean SMIs of reference groups were as cutoff values of low muscle mass in Iranian population. The peak ASM values were 21.35 ± 0.12 Kg and 13.68 ± 0.10 Kg, and the age at peak ASM were 26 (24-28) years and 34 (33-35) years for men and women, respectively. Mean and SD of SMI in those ages were 7.01 ± 0.02 Kg/m 2 and 5.44 ± 0.02 Kg/m 2 among men and women, respectively. Calculated cutoff values of low muscle mass among the Iranian population were 7.0 Kg/m 2 and 5.4 Kg/m 2 among men and women, respectively. Iranian reference values of SMI for both genders were similar to Asia Working Group for Sarcopenia recommendation and lower than the United States and European values. Further studies from different nations and the Middle East countries are needed to obtain reference values for populations, enabling the researchers for comparison and also more valid reports on sarcopenia prevalence.

  11. Psoas muscle cross-sectional area as a measure of whole body lean muscle mass in maintenance hemodialysis patients

    Science.gov (United States)

    Morrell, Glen R.; Ikizler, Talat A.; Chen, Xiaorui; Heilbrun, Marta E.; Wei, Guo; Boucher, Robert; Beddhu, Srinivasan

    2016-01-01

    Objective We investigate whether psoas or paraspinous muscle area measured on a single L4–5 image is a useful measure of whole lean body mass compared to dedicated mid-thigh magnetic resonance imaging (MRI). Design Observational study. Setting Outpatient dialysis units and a research clinic. Subjects 105 adult participants on maintenance hemodialysis. No control group was used. Exposure variables Psoas muscle area, paraspinous muscle area, and mid-thigh muscle area (MTMA) were measured by MRI. Main outcome measure Lean body mass was measured by dual-energy absorptiometry (DEXA) scan. Results In separate multivariable linear regression models, psoas, paraspinous, and mid-thigh muscle area were associated with increase in lean body mass. In separate multivariate logistic regression models, c-statistics for diagnosis of sarcopenia (defined as lean body mass) were 0.69 for paraspinous muscle area, 0.81 for psoas muscle area, and 0.89 for mid-thigh muscle area. With sarcopenia defined as lean body mass, the corresponding c-statistics were 0.71, 0.92, and 0.94. Conclusions We conclude that psoas muscle area provides a good measure of whole body muscle mass, better than paraspinous muscle area but slightly inferior to mid thigh measurement. Hence, in body composition studies a single axial MR image at the L4–L5 level can be used to provide information on both fat and muscle and may eliminate the need for time-consuming measurement of muscle area in the thigh. PMID:26994780

  12. Comparison of muscle/lean mass measurement methods: correlation with functional and biochemical testing.

    Science.gov (United States)

    Buehring, B; Siglinsky, E; Krueger, D; Evans, W; Hellerstein, M; Yamada, Y; Binkley, N

    2018-03-01

    DXA-measured lean mass is often used to assess muscle mass but has limitations. Thus, we compared DXA lean mass with two novel methods-bioelectric impedance spectroscopy and creatine (methyl-d3) dilution. The examined methodologies did not measure lean mass similarly and the correlation with muscle biomarkers/function varied. Muscle function tests predict adverse health outcomes better than lean mass measurement. This may reflect limitations of current mass measurement methods. Newer approaches, e.g., bioelectric impedance spectroscopy (BIS) and creatine (methyl-d3) dilution (D3-C), may more accurately assess muscle mass. We hypothesized that BIS and D3-C measured muscle mass would better correlate with function and bone/muscle biomarkers than DXA measured lean mass. Evaluations of muscle/lean mass, function, and serum biomarkers were obtained in older community-dwelling adults. Mass was assessed by DXA, BIS, and orally administered D3-C. Grip strength, timed up and go, and jump power were examined. Potential muscle/bone serum biomarkers were measured. Mass measurements were compared with functional and serum data using regression analyses; differences between techniques were determined by paired t tests. Mean (SD) age of the 112 (89F/23M) participants was 80.6 (6.0) years. The lean/muscle mass assessments were correlated (.57-.88) but differed (p Lean mass measures were unrelated to the serum biomarkers measured. These three methodologies do not similarly measure muscle/lean mass and should not be viewed as being equivalent. Functional tests assessing maximal muscle strength/power (grip strength and jump power) correlated with all mass measures whereas gait speed was not. None of the selected serum measures correlated with mass. Efforts to optimize muscle mass assessment and identify their relationships with health outcomes are needed.

  13. Relationship of interleukin-6 and tumor necrosis factor-alpha with muscle mass and muscle strength in elderly men and women : the Health ABC Study

    NARCIS (Netherlands)

    Visser, Marjolein; Pahor, Marco; Taaffe, Dennis R; Goodpaster, Bret H; Simonsick, Eleanor M; Newman, Anne B; Nevitt, Michael; Harris, Tamara B

    BACKGROUND: A decline in muscle mass and muscle strength characterizes normal aging. As clinical and animal studies show a relationship between higher cytokine levels and low muscle mass, the aim of this study was to investigate whether markers of inflammation are associated with muscle mass and

  14. Fat-Free Mass and Skeletal Muscle Mass Five Years After Bariatric Surgery.

    Science.gov (United States)

    Davidson, Lance E; Yu, Wen; Goodpaster, Bret H; DeLany, James P; Widen, Elizabeth; Lemos, Thaisa; Strain, Gladys W; Pomp, Alfons; Courcoulas, Anita P; Lin, Susan; Janumala, Isaiah; Thornton, John C; Gallagher, Dympna

    2018-07-01

    This study investigated changes in fat-free mass (FFM) and skeletal muscle 5 years after surgery in participants from the Longitudinal Assessment of Bariatric Surgery-2 trial. A three-compartment model assessed FFM, and whole-body magnetic resonance imaging (MRI) quantified skeletal muscle mass prior to surgery (T0) and 1 year (T1), 2 years (T2), and 5 years (T5) postoperatively in 93 patients (85% female; 68% Caucasian; age 44.2 ± 11.6 years) who underwent gastric bypass (RYGB), sleeve gastrectomy, or adjustable gastric band. Repeated-measures mixed models were used to analyze the data. Significant weight loss occurred across all surgical groups in females from T0 to T1. FFM loss from T0 to T1 was greater after RYGB (mean ± SE: -6.9 ± 0.6 kg) than adjustable gastric band (-3.5 ± 1.4 kg; P FFM (-3.3 ± 0.7 kg; P FFM loss while maintaining FFM and skeletal muscle from T1 to T5. Between 1 and 5 years following common bariatric procedures, FFM and skeletal muscle are maintained or decrease minimally. The changes observed in FFM and muscle during the follow-up phase may be consistent with aging. © 2018 The Obesity Society.

  15. Association of low back pain with muscle stiffness and muscle mass of the lumbar back muscles, and sagittal spinal alignment in young and middle-aged medical workers.

    Science.gov (United States)

    Masaki, Mitsuhiro; Aoyama, Tomoki; Murakami, Takashi; Yanase, Ko; Ji, Xiang; Tateuchi, Hiroshige; Ichihashi, Noriaki

    2017-11-01

    Muscle stiffness of the lumbar back muscles in low back pain (LBP) patients has not been clearly elucidated because quantitative assessment of the stiffness of individual muscles was conventionally difficult. This study aimed to examine the association of LBP with muscle stiffness assessed using ultrasonic shear wave elastography (SWE) and muscle mass of the lumbar back muscle, and spinal alignment in young and middle-aged medical workers. The study comprised 23 asymptomatic medical workers [control (CTR) group] and 9 medical workers with LBP (LBP group). Muscle stiffness and mass of the lumbar back muscles (lumbar erector spinae, multifidus, and quadratus lumborum) in the prone position were measured using ultrasonic SWE. Sagittal spinal alignment in the standing and prone positions was measured using a Spinal Mouse. The association with LBP was investigated by multiple logistic regression analysis with a forward selection method. The analysis was conducted using the shear elastic modulus and muscle thickness of the lumbar back muscles, and spinal alignment, age, body height, body weight, and sex as independent variables. Multiple logistic regression analysis showed that muscle stiffness of the lumbar multifidus muscle and body height were significant and independent determinants of LBP, but that muscle mass and spinal alignment were not. Muscle stiffness of the lumbar multifidus muscle in the LBP group was significantly higher than that in the CTR group. The results of this study suggest that LBP is associated with muscle stiffness of the lumbar multifidus muscle in young and middle-aged medical workers. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. A low muscle mass increases mortality in compensated cirrhotic patients with sepsis.

    Science.gov (United States)

    Lucidi, Cristina; Lattanzi, Barbara; Di Gregorio, Vincenza; Incicco, Simone; D'Ambrosio, Daria; Venditti, Mario; Riggio, Oliviero; Merli, Manuela

    2018-05-01

    Severe infections and muscle wasting are both associated to poor outcome in cirrhosis. A possible synergic effect of these two entities in cirrhotic patients has not been previously investigated. We aimed at analysing if a low muscle mass may deteriorate the outcome of cirrhotic patients with sepsis. Consecutive cirrhotic patients hospitalized for sepsis were enrolled in the study. Patients were classified for the severity of liver impairment (Child-Pugh class) and for the presence of "low muscle mass" (mid-arm muscle circumferencelow muscle mass. In patients with and without low muscle mass, severity of liver disease and characteristics of infections were similar. Mortality tended to be higher in patients with low muscle mass (47% vs 26%, P = .06). A multivariate analysis selected low muscle mass (P low muscle mass compared with those without (50% vs 16%; P = .01). The mortality rate and the incidence of complications in malnourished patients classified in Child-Pugh A-B were similar to those Child-Pugh C. Low muscle mass worsen prognosis in cirrhotic patients with severe infections. This is particularly evident in patients with Child A-B cirrhosis in whom the coexistence of low muscle mass and sepsis caused a negative impact on mortality similar to that observable in all Child C patients with sepsis. © 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  17. Alfacalcidol improves muscle power, muscle function and balance in elderly patients with reduced bone mass.

    Science.gov (United States)

    Schacht, E; Ringe, Johann D

    2012-01-01

    We investigated the effect of daily therapy with 1 mcg alfacalcidol (Doss(®)-TEVA/AWD-pharma) on muscle power, muscle function, balance performance and fear of falls in an open, multi-centered, uncontrolled, prospective study on a cohort of patients with reduced bone mass. Among the 2,097 participants, 87.1% were post-menopausal women and 12.9% were men. Mean age was 74.8 years and mean body mass index (BMI) 26.3 kg/m². A total of 75.3% of the study population had osteoporosis, 81% a diagnosis of "increased risk of falls" and 70.1% had a creatinine clearance (CrCl) of power tests at onset and after 3 and 6 months: the timed up and go test (TUG) and the chair rising test (CRT). At baseline and after 6 months, participants performed the tandem gait test (TGT) and filled out a questionnaire evaluating fear of falling. Successful performance in the muscle tests is associated with a significantly lower risk of falls and non-vertebral fractures in elderly patients (successful test performance: TUG ≤ 10 s (sec), CRT ≤ 10 s, TGT ≥ 8 steps). A significant improvement in the performance of the two muscle tests was proved already after 3 months of treatment with alfacalcidol and further increased by the end of the therapeutic intervention. There were significant increases in the number of participants able to successfully perform the tests: 24.6% at baseline and 46.3% at the end of trial for the TUG (P balance test (TGT) increased from 36.0% at onset to 58.6% at the end of the trial (P power, muscle function and balance and reduces fear of falls. The significant improvement in the three muscle and balance tests and fear of falls may have a preventative effect on falls and fractures. We suggest that the quantitative risk tests used in this study could be reliable surrogate parameters for the risk of falls and fractures in elderly patients.

  18. Relationship between oxidative stress and muscle mass loss in early postmenopause: an exploratory study.

    Science.gov (United States)

    Zacarías-Flores, Mariano; Sánchez-Rodríguez, Martha A; García-Anaya, Oswaldo Daniel; Correa-Muñoz, Elsa; Mendoza-Núñez, Víctor Manuel

    2018-04-09

    Endocrine changes due to menopause have been associated to oxidative stress and muscle mass loss. The study objective was to determine the relationship between both variables in early postmenopause. An exploratory, cross-sectional study was conducted in 107 pre- and postmenopausal women (aged 40-57 years). Levels of serum lipid peroxides and uric acid and enzymes superoxide dismutase and glutathione peroxidase, as well as total plasma antioxidant capacity were measured as oxidative stress markers. Muscle mass using bioelectrical impedance and muscle strength using dynamometry were also measured. Muscle mass, skeletal muscle index, fat-free mass, and body mass index were calculated. More than 90% of participants were diagnosed with overweight or obesity. Postmenopausal women had lower values of muscle mass and strength markers, with a negative correlation between lipid peroxide level and skeletal muscle index (r= -0.326, p<.05), and a positive correlation between uric acid and skeletal muscle index (r=0.295, p<.05). A multivariate model including oxidative stress markers, age, and waist circumference showed lipid peroxide level to be the main contributor to explain the decrease in skeletal muscle mass in postmenopause, since for every 0.1μmol/l increase in lipid peroxide level, skeletal muscle index decreases by 3.03 units. Our findings suggest an association between increased oxidative stress and muscle mass loss in early postmenopause. Copyright © 2018 SEEN y SED. Publicado por Elsevier España, S.L.U. All rights reserved.

  19. Influence of temperature on muscle recruitment and muscle function in vivo.

    Science.gov (United States)

    Rome, L C

    1990-08-01

    Temperature has a large influence on the maximum velocity of shortening (Vmax) and maximum power output of muscle (Q10 = 1.5-3). In some animals, maximum performance and maximum sustainable performance show large temperature sensitivities, because these parameters are dependent solely on mechanical power output of the muscles. The mechanics of locomotion (sarcomere length excursions and muscle-shortening velocities, V) at a given speed, however, are precisely the same at all temperatures. Animals compensate for the diminished power output of their muscles at low temperatures by compressing their recruitment order into a narrower range of locomotor speeds, that is, recruiting more muscle fibers and faster fiber types at a given speed. By examining V/Vmax, I calculate that fish at 10 degrees C must recruit 1.53-fold greater fiber cross section than at 20 degrees C. V/Vmax also appears to be an important design constraint in muscle. It sets the lowest V and the highest V over which a muscle can be used effectively. Because the Vmax of carp slow red muscle has a Q10 of 1.6 between 10 and 20 degrees C, the slow aerobic fibers can be used over a 1.6-fold greater range of swim speeds at the warmer temperature. In some species of fish, Vmax can be increased during thermal acclimation, enabling animals to swim at higher speeds.

  20. The effect Mat Pilates practice on muscle mass in elderly women

    Directory of Open Access Journals (Sweden)

    Leliz Cristina Sampaio Queiroz

    2016-01-01

    Full Text Available Objective: to verify that the Mat Pilates practice increases muscle mass in elderly women. Methods: quasi-experimental study with primary data collection and with a convenience sample. The muscle mass of 43 elderly was evaluated for 11 weeks, by calculating the arm muscle area, before and after the intervention. Results:statistically significant difference was observed (p<0.002 between the average value of the arm muscle area, before (35.56cm2 and after the exercises (42.72cm2. Conclusion: mat Pilates program generates positive effect on increasing the muscle mass of elderly.

  1. Creatine Loading Does Not Preserve Muscle Mass or Strength During Leg Immobilization in Healthy, Young Males

    NARCIS (Netherlands)

    Backx, Evelien M.P.; Hangelbroek, Roland; Snijders, Tim; Verscheijden, Marie Louise; Verdijk, Lex B.; Groot, de Lisette C.P.G.M.; Loon, van Luc J.C.

    2017-01-01

    Background: A short period of leg immobilization leads to rapid loss of muscle mass and strength. Creatine supplementation has been shown to increase lean body mass in active individuals and can be used to augment gains in muscle mass and strength during prolonged resistance-type exercise

  2. The Influence of High-Frequency Gravitational Waves Upon Muscles

    International Nuclear Information System (INIS)

    Moy, Lawrence S.; Baker, Robert M. L. Jr

    2007-01-01

    The objective of this paper is to present a theory for the possible influence of high-frequency gravitational waves or HFGWs and pulsed micro-current electromagnetic waves or EMs on biological matter specifically on muscle cells and myofibroblasts. The theory involves consideration of the natural frequency of contractions and relaxations of muscles, especially underlying facial skin, and the possible influence of HFGWs on that process. GWs pass without attenuation through all material thus conventional wisdom would dictate that GWs would have no influence on biological matter. On the other hand, GWs can temporarily modify a gravitational field in some locality if they are of high frequency and such a modification might have an influence in changing the skin muscles' natural frequency. Prior to the actual laboratory generation of HFGWs their influence can be emulated by micro-current EM pulses to the skin and some evidence presented here on that effect may predict the influence of HFGWs. We believe that the HFGW pulsations lead to increased muscle activity and may serve to reverse the aging process. A novel theoretical framework concerning these relaxation phenomena is one result of the paper. Another result is the analysis of the possible delivery system of the FBAR-generated HFGWs, the actual power of the generated HFGWs, and the system's application to nanostructural modification of the skin or muscle cells. It is concluded that a series of non-evasive experiments, which are identified, will have the potential to test theory by detecting and analyzing the possible HFGWs change in polarization, refraction, etc. after their interaction with the muscle cells

  3. Correlation between Body Mass Index, Gender, and Skeletal Muscle Mass Cut off Point in Bandung

    Directory of Open Access Journals (Sweden)

    Richi Hendrik Wattimena

    2017-09-01

    Full Text Available Objective: To determine the average skeletal muscle mass (SMM value in young adults as a reference population; to analyze the correlation of gender, and body mass index to the cut off point; and to determine skeletal muscle mass cut off points of population in Bandung, Indonesia. Methods: This was a cross-sectional study involving 199 participants, 122 females and 77 males. The sampling technique used was the multistage random sampling. The participants were those who lived in four major regions in Bandung, Indonesia: Sukajadi, Cicadas, Buah Batu, and Cibaduyut. Results: The average appendicular skeletal mass index (ASMI in females and males based on body mass index (BMI were identified. The average ASMI values for normal BMI in females was 5.982±0.462 kg/m2 while the average ASMI values normal BMI for males was 7.581±0.744 kg/m2 Conclusions: A correlation between BMI and ASMI that was considered statistically significant was found in females (0.7712; p<0.05 and a very significant correlation was seen in males (0.870; p<0.05. The cut off points were defined by the normal BMI, which were 5.059 for females and 6.093 for males.

  4. Supplemental protein in support of muscle mass and health: advantage whey.

    Science.gov (United States)

    Devries, Michaela C; Phillips, Stuart M

    2015-03-01

    Skeletal muscle is an integral body tissue playing key roles in strength, performance, physical function, and metabolic regulation. It is essential for athletes to ensure that they have optimal amounts of muscle mass to ensure peak performance in their given sport. However, the role of maintaining muscle mass during weight loss and as we age is an emerging concept, having implications in chronic disease prevention, functional capacity, and quality of life. Higher-protein diets have been shown to: (1) promote gains in muscle mass, especially when paired with resistance training; (2) spare muscle mass loss during caloric restriction; and (3) attenuate the natural loss of muscle mass that accompanies aging. Protein quality is important to the gain and maintenance of muscle mass. Protein quality is a function of protein digestibility, amino acid content, and the resulting amino acid availability to support metabolic function. Whey protein is one of the highest-quality proteins given its amino acid content (high essential, branched-chain, and leucine amino acid content) and rapid digestibility. Consumption of whey protein has a robust ability to stimulate muscle protein synthesis. In fact, whey protein has been found to stimulate muscle protein synthesis to a greater degree than other proteins such as casein and soy. This review examines the existing data supporting the role for protein consumption, with an emphasis on whey protein, in the regulation of muscle mass and body composition in response to resistance training, caloric restriction, and aging. © 2015 Institute of Food Technologists®

  5. Baseline muscle mass is a poor predictor of functional overload-induced gain in the mouse model

    Directory of Open Access Journals (Sweden)

    Audrius Kilikevicius

    2016-11-01

    Full Text Available Genetic background contributes substantially to individual variability in muscle mass. Muscle hypertrophy in response to resistance training can also vary extensively. However, it is less clear if muscle mass at baseline is predictive of the hypertrophic response.The aim of this study was to examine the effect of genetic background on variability in muscle mass at baseline and in the adaptive response of the mouse fast- and slow-twitch muscles to overload. Males of eight laboratory mouse strains: C57BL/6J (B6, n=17, BALB/cByJ (n=7, DBA/2J (D2, n=12, B6.A-(rs3676616-D10Utsw1/Kjn (B6.A, n=9, C57BL/6J-Chr10A/J/NaJ (B6.A10, n=8, BEH+/+ (n=11, BEH (n=12 and DUHi (n=12, were studied. Compensatory growth of soleus and plantaris muscles was triggered by a 4-week overload induced by synergist unilateral ablation. Muscle weight in the control leg (baseline varied from 5.2±07 mg soleus and 11.4±1.3 mg plantaris in D2 mice to 18.0±1.7 mg soleus in DUHi and 43.7±2.6 mg plantaris in BEH (p<0.001 for both muscles. In addition, soleus in the B6.A10 strain was ~40% larger (p<0.001 compared to the B6. Functional overload increased muscle weight, however, the extent of gain was strain-dependent for both soleus (p<0.01 and plantaris (p<0.02 even after accounting for the baseline differences. For the soleus muscle, the BEH strain emerged as the least responsive, with a 1.3-fold increase, compared to a 1.7-fold gain in the most responsive D2 strain, and there was no difference in the gain between the B6.A10 and B6 strains. The BEH strain appeared the least responsive in the gain of plantaris as well, 1.3-fold, compared to ~1.5-fold gain in the remaining strains. We conclude that variation in muscle mass at baseline is not a reliable predictor of that in the overload-induced gain. This suggests that a different set of genes influence variability in muscle mass acquired in the process of normal development, growth and maintenance, and in the process of adaptive

  6. A New Equation to Estimate Muscle Mass from Creatinine and Cystatin C.

    Directory of Open Access Journals (Sweden)

    Sun-wook Kim

    Full Text Available With evaluation for physical performance, measuring muscle mass is an important step in detecting sarcopenia. However, there are no methods to estimate muscle mass from blood sampling.To develop a new equation to estimate total-body muscle mass with serum creatinine and cystatin C level, we designed a cross-sectional study with separate derivation and validation cohorts. Total body muscle mass and fat mass were measured using dual-energy x-ray absorptiometry (DXA in 214 adults aged 25 to 84 years who underwent physical checkups from 2010 to 2013 in a single tertiary hospital. Serum creatinine and cystatin C levels were also examined.Serum creatinine was correlated with muscle mass (P < .001, and serum cystatin C was correlated with body fat mass (P < .001 after adjusting glomerular filtration rate (GFR. After eliminating GFR, an equation to estimate total-body muscle mass was generated and coefficients were calculated in the derivation cohort. There was an agreement between muscle mass calculated by the novel equation and measured by DXA in both the derivation and validation cohort (P < .001, adjusted R2 = 0.829, β = 0.95, P < .001, adjusted R2 = 0.856, β = 1.03, respectively.The new equation based on serum creatinine and cystatin C levels can be used to estimate total-body muscle mass.

  7. Muscle Mass Depletion Associated with Poor Outcome of Sepsis in the Emergency Department.

    Science.gov (United States)

    Lee, YoonJe; Park, Hyun Kyung; Kim, Won Young; Kim, Myung Chun; Jung, Woong; Ko, Byuk Sung

    2018-05-08

    Muscle mass depletion has been suggested to predict morbidity and mortality in various diseases. However, it is not well known whether muscle mass depletion is associated with poor outcome in sepsis. We hypothesized that muscle mass depletion is associated with poor outcome in sepsis. Retrospective observational study was conducted in an emergency department during a 9-year period. Medical records of 627 patients with sepsis were reviewed. We divided the patients into 2 groups according to 28-day mortality and compared the presence of muscle mass depletion assessed by the cross-sectional area of the psoas muscle at the level of the third lumbar vertebra on abdomen CT scans. Univariate and multivariate logistic regression analyses were conducted to examine the association of scarcopenia on the outcome of sepsis. A total of 274 patients with sepsis were finally included in the study: 45 (16.4%) did not survive on 28 days and 77 patients (28.1%) were identified as having muscle mass depletion. The presence of muscle mass depletion was independently associated with 28-day mortality on multivariate logistic analysis (OR 2.79; 95% CI 1.35-5.74, p = 0.01). Muscle mass depletion evaluated by CT scan was associated with poor outcome of sepsis patients. Further studies on the appropriateness of specific treatment for muscle mass depletion with sepsis are needed. © 2018 S. Karger AG, Basel.

  8. Relationships of 35 lower limb muscles to height and body mass quantified using MRI.

    Science.gov (United States)

    Handsfield, Geoffrey G; Meyer, Craig H; Hart, Joseph M; Abel, Mark F; Blemker, Silvia S

    2014-02-07

    Skeletal muscle is the most abundant tissue in the body and serves various physiological functions including the generation of movement and support. Whole body motor function requires adequate quantity, geometry, and distribution of muscle. This raises the question: how do muscles scale with subject size in order to achieve similar function across humans? While much of the current knowledge of human muscle architecture is based on cadaver dissection, modern medical imaging avoids limitations of old age, poor health, and limited subject pool, allowing for muscle architecture data to be obtained in vivo from healthy subjects ranging in size. The purpose of this study was to use novel fast-acquisition MRI to quantify volumes and lengths of 35 major lower limb muscles in 24 young, healthy subjects and to determine if muscle size correlates with bone geometry and subject parameters of mass and height. It was found that total lower limb muscle volume scales with mass (R(2)=0.85) and with the height-mass product (R(2)=0.92). Furthermore, individual muscle volumes scale with total muscle volume (median R(2)=0.66), with the height-mass product (median R(2)=0.61), and with mass (median R(2)=0.52). Muscle volume scales with bone volume (R(2)=0.75), and muscle length relative to bone length is conserved (median s.d.=2.1% of limb length). These relationships allow for an arbitrary subject's individual muscle volumes to be estimated from mass or mass and height while muscle lengths may be estimated from limb length. The dataset presented here can further be used as a normative standard to compare populations with musculoskeletal pathologies. © 2013 Published by Elsevier Ltd.

  9. Non-Hodgkin lymphoma in skeletal muscle manifesting as homogeneous masses with CT attenuation similar to muscle

    International Nuclear Information System (INIS)

    Panicek, D.M.; Lautin, J.L.; Schwartz, L.H.; Castellino, R.A.

    1997-01-01

    Two cases are presented of masses in muscle due to non-Hodgkin lymphoma (NHL) that were homogeneous and isoattenuating to normal muscle on CT. In each case, the mass was clinically suspected of representing soft tissue sarcoma. However, the masses were relatively inapparent on CT, being visible predominantly as mass effect - an appearance unlike that of soft tissue sarcomas. It is important to be aware that NHL in muscle can be difficult to detect at CT, even with intravenous contrast enhancement; therefore, a clinically apparent mass should not be dismissed on the basis of an apparently unremarkable CT scan of the region. Such findings should suggest the diagnosis of NHL rather than sarcoma. (orig.)

  10. Influence of socioeconomic factors in muscle dysmorphia

    Directory of Open Access Journals (Sweden)

    Mercedes Rizo-Baeza

    2018-05-01

    Full Text Available Abstract: Introduction and objective: In muscle dysmorphia (MD the patient thinks he is smaller and less muscular than he really is. As in other addictive diseases, its prevention and early diagnosis are the key to avoid associated disorders. It is established as an objective to determine if there are associated socio-demographic factors. Material and methods: Cross-sectional observational study of 140 men, between 16-45 years old, who practice bodybuilding in gyms of different socioeconomic levels, at least 6 months prior to the study, 4 days / week, 1 hour / day, who signed the informed consent and without chronic illness. The main variable was the presence of symptoms of DM using the muscle appearance satisfaction scale (44 patients and the secondary variables were age, coexistence, children, educational level and monthly income. Frequencies were used in the qualitative variables, and averages and standard deviations in the quantitative variables, in the bivariate analysis of the Chisquare test and the t-student test respectively and the binary logistic regression (presence / absence of MD to eliminate confounding factors, the probabilities were calculated associated Results: The gymnasts have an average age of 26.1 (SD = 7.1 years; the majority live with their parents (56.4%; they do not have children (89.3%; the academic levels are balanced and the economic income is mostly low / medium (79.3%. In the bivariate analysis, is observed a higher risk at a younger age (p = 0.027 and when they live with their parents (limit of significance. Significance is not observed with the variables having children, educational level or economic income. In the binary logistic regression these meanings are lost, although the graphic representation of the probability in relation with age seems to be a risk factor, as well as living with the parents or as a couple. Conclusion: Among men who practice bodybuilding, it is usually a risk to suffer MD, to be younger

  11. The Intriguing Regulators of Muscle Mass in Sarcopenia and Muscular Dystrophy

    OpenAIRE

    Sakuma, Kunihiro; Aoi, Wataru; Yamaguchi, Akihiko

    2014-01-01

    Recent advances in our understanding of the biology of muscle have led to new interest in the pharmacological treatment of muscle wasting. Loss of muscle mass and increased intramuscular fibrosis occur in both sarcopenia and muscular dystrophy. Several regulators (mammalian target of rapamycin, serum response factor, atrogin-1, myostatin, etc.) seem to modulate protein synthesis and degradation or transcription of muscle-specific genes during both sarcopenia and muscular dystrophy. This revie...

  12. Comparison of skeletal muscle mass to fat-free mass ratios among different ethnic groups.

    Science.gov (United States)

    Abe, T; Bemben, M G; Kondo, M; Kawakami, Y; Fukunaga, T

    2012-01-01

    Asians seem to have less skeletal muscle mass (SMM) than other ethnic groups, but it is not clear whether relative SMM, i.e., SMM / height square or SMM to fat-free mass (FFM) ratio, differs among different ethnic groups at the same level of body mass index (BMI). To compare the SMM to fat-free mass (FFM) ratio as well as anthropometric variables and body composition among 3 ethnic groups. Three hundred thirty-nine Japanese, 343 Brazilian, and 183 German men and women were recruited for this cross-sectional study. Muscle thickness (MTH) and subcutaneous fat thickness (FTH) were measured by ultrasound at nine sites on the anterior and posterior aspects of the body. FTH was used to estimate the body density, from which fat mass and fat-free mass (FFM) was calculated by using Brozek equation. Total SMM was estimated from ultrasound-derived prediction equations. Percentage body fat was similar among the ethnic groups in men, while Brazilians were higher than Japanese in women. In German men and women, absolute SMM and FFM were higher than in their Japanese and Brazilians counterparts. SMM index and SMM:FFM ratios were similar among the ethnic groups in women, excluding SMM:FFM ratio in Brazilian. In men, however, these relative values (SMM index and SMM:FFM ratio) were still higher in Germans. After adjusting for age and BMI, the SMM index and SMM:FFM ratios were lower in Brazilian men and women compared with the other two ethnic groups, while the SMM index and SMM:FFM ratios were similar in Japanese and German men and women, excluding SMM:FFM ratio in women. Our results suggest that relative SMM is not lower in Asian populations compared with European populations after adjusted by age and BMI.

  13. Influence of muscle groups' activation on proximal femoral growth tendency.

    Science.gov (United States)

    Yadav, Priti; Shefelbine, Sandra J; Pontén, Eva; Gutierrez-Farewik, Elena M

    2017-12-01

    Muscle and joint contact force influence stresses at the proximal growth plate of the femur and thus bone growth, affecting the neck shaft angle (NSA) and femoral anteversion (FA). This study aims to illustrate how different muscle groups' activation during gait affects NSA and FA development in able-bodied children. Subject-specific femur models were developed for three able-bodied children (ages 6, 7, and 11 years) using magnetic resonance images. Contributions of different muscle groups-hip flexors, hip extensors, hip adductors, hip abductors, and knee extensors-to overall hip contact force were computed. Specific growth rate for the growth plate was computed, and the growth was simulated in the principal stress direction at each element in the growth front. The predicted growth indicated decreased NSA and FA (of about [Formula: see text] over a four-month period) for able-bodied children. Hip abductors contributed the most, and hip adductors, the least, to growth rate. All muscles groups contributed to a decrease in predicted NSA ([Formula: see text]0.01[Formula: see text]-0.04[Formula: see text] and FA ([Formula: see text]0.004[Formula: see text]-[Formula: see text]), except hip extensors and hip adductors, which showed a tendency to increase the FA ([Formula: see text]0.004[Formula: see text]-[Formula: see text]). Understanding influences of different muscle groups on long bone growth tendency can help in treatment planning for growing children with affected gait.

  14. Creatine Supplementation and Skeletal Muscle Metabolism for Building Muscle Mass- Review of the Potential Mechanisms of Action.

    Science.gov (United States)

    Farshidfar, Farnaz; Pinder, Mark A; Myrie, Semone B

    2017-01-01

    Creatine, a very popular supplement among athletic populations, is of growing interest for clinical applications. Since over 90% of creatine is stored in skeletal muscle, the effect of creatine supplementation on muscle metabolism is a widely studied area. While numerous studies over the past few decades have shown that creatine supplementation has many favorable effects on skeletal muscle physiology and metabolism, including enhancing muscle mass (growth/hypertrophy); the underlying mechanisms are poorly understood. This report reviews studies addressing the mechanisms of action of creatine supplementation on skeletal muscle growth/hypertrophy. Early research proposed that the osmotic effect of creatine supplementation serves as a cellular stressor (osmosensing) that acts as an anabolic stimulus for protein synthesis signal pathways. Other reports indicated that creatine directly affects muscle protein synthesis via modulations of components in the mammalian target of rapamycin (mTOR) pathway. Creatine may also directly affect the myogenic process (formation of muscle tissue), by altering secretions of myokines, such as myostatin and insulin-like growth factor-1, and expressions of myogenic regulatory factors, resulting in enhanced satellite cells mitotic activities and differentiation into myofiber. Overall, there is still no clear understanding of the mechanisms of action regarding how creatine affects muscle mass/growth, but current evidence suggests it may exert its effects through multiple approaches, with converging impacts on protein synthesis and myogenesis. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  15. Bio-impedance analysis for appendicular skeletal muscle mass assessment in (pre-) frail elderly people

    NARCIS (Netherlands)

    Baar, van H.; Hulshof, P.J.M.; Tieland, C.A.B.; Groot, de C.P.G.M.

    2015-01-01

    Background & aims Screening populations for skeletal muscle mass (SMM) is important for early detection of sarcopenia. Our aim was to develop an age specific bio-impedance (BI) prediction equation for the assessment of appendicular skeletal muscle mass (ASMM) in (pre-) frail elderly people aged

  16. Relationship of Muscle Mass Determined by DEXA with Spirometric Results in Healthy Individuals.

    Science.gov (United States)

    Martín Holguera, Rafael; Turrión Nieves, Ana Isabel; Rodríguez Torres, Rosa; Alonso, María Concepción

    2017-07-01

    Muscle mass maybe a determining factor in the variability of spirometry results in individuals of the same sex and age who have similar anthropometric characteristics. The aim of this study was to determine the association between spirometric results from healthy individuals and their muscle mass assessed by dual energy X-ray absorptiometry (DEXA). A sample of 161 women and 144 men, all healthy non-smokers, was studied. Ages ranged from18 to77years. For each subject, spirometry results and total and regional lean mass values obtained by full body DEXA were recorded. A descriptive analysis of the variables and a regression analysis were performed to study the relationship between spirometric variables and lean body mass, correcting for age and body mass index (BMI). In both sexes all muscle mass variables correlated positively and significantly with spirometric variables, and to a greater extent in men. After partial adjustment of correlations by age and BMI, the factor which best explains the spirometric variables is the total lean body mass in men, and trunk lean body mass in women. In men, muscle mass in the lower extremities is most closely associated with spirometric results. In women, it is the muscle mass of the trunk. In both sexes muscle mass mainly affects FEV 1 . Copyright © 2016 SEPAR. Publicado por Elsevier España, S.L.U. All rights reserved.

  17. Differences among skeletal muscle mass indices derived from height-, weight-, and body mass index-adjusted models in assessing sarcopenia

    Science.gov (United States)

    Kim, Kyoung Min; Jang, Hak Chul; Lim, Soo

    2016-01-01

    Aging processes are inevitably accompanied by structural and functional changes in vital organs. Skeletal muscle, which accounts for 40% of total body weight, deteriorates quantitatively and qualitatively with aging. Skeletal muscle is known to play diverse crucial physical and metabolic roles in humans. Sarcopenia is a condition characterized by significant loss of muscle mass and strength. It is related to subsequent frailty and instability in the elderly population. Because muscle tissue is involved in multiple functions, sarcopenia is closely related to various adverse health outcomes. Along with increasing recognition of the clinical importance of sarcopenia, several international study groups have recently released their consensus on the definition and diagnosis of sarcopenia. In practical terms, various skeletal muscle mass indices have been suggested for assessing sarcopenia: appendicular skeletal muscle mass adjusted for height squared, weight, or body mass index. A different prevalence and different clinical implications of sarcopenia are highlighted by each definition. The discordances among these indices have emerged as an issue in defining sarcopenia, and a unifying definition for sarcopenia has not yet been attained. This review aims to compare these three operational definitions and to introduce an optimal skeletal muscle mass index that reflects the clinical implications of sarcopenia from a metabolic perspective. PMID:27334763

  18. Growth hormone mitigates loss of periosteal bone formation and muscle mass in disuse osteopenic rats

    DEFF Research Database (Denmark)

    Grubbe, M-C; Thomsen, Jesper Skovhus; Nyengaard, J R

    2014-01-01

    Growth hormone (GH) is a potent anabolic agent capable of increasing both bone and muscle mass. The aim was to investigate whether GH could counteract disuse-induced loss of bone and muscle mass in a rat model. Paralysis was induced by injecting 4 IU Botox (BTX) into the muscles of the right hind...... of periosteal BFR/BS (2-fold increase vs. BTX, Pmuscle mass (+29% vs. BTX, Pmuscle CSA (+11%, P=0.064). In conclusion, GH mitigates disuse......BMD, -13%, Pmuscle mass (-69%, Pmuscle cell cross sectional area (CSA) (-73%, P

  19. Influence of Passive Muscle Tension on Electromechanical Delay in Humans

    Science.gov (United States)

    Lacourpaille, Lilian; Hug, François; Nordez, Antoine

    2013-01-01

    Background Electromechanical delay is the time lag between onsets of muscle activation and muscle force production and reflects both electro-chemical processes and mechanical processes. The aims of the present study were two-fold: to experimentally determine the slack length of each head of the biceps brachii using elastography and to determine the influence of the length of biceps brachii on electromechanical delay and its electro-chemical/mechanical processes using very high frame rate ultrasound. Methods/Results First, 12 participants performed two passive stretches to evaluate the change in passive tension for each head of the biceps brachii. Then, they underwent two electrically evoked contractions from 120 to 20° of elbow flexion (0°: full extension), with the echographic probe maintained over the muscle belly and the myotendinous junction of biceps brachii. The slack length was found to occur at 95.5 ± 6.3° and 95.3 ± 8.2° of the elbow joint angle for the long and short heads of the biceps brachii, respectively. The electromechanical delay was significantly longer at 120° (16.9 ± 3.1 ms; p0.95). Conclusion In contrast to previous observations on gastrocnemius medialis, the onset of muscle motion and the onset of myotendinous junction motion occurred simultaneously regardless of the length of the biceps brachii. That suggests that the between-muscles differences reported in the literature cannot be explained by different muscle passive tension but instead may be attributable to muscle architectural differences. PMID:23308153

  20. mTOR as a Key Regulator in Maintaining Skeletal Muscle Mass

    Directory of Open Access Journals (Sweden)

    Mee-Sup Yoon

    2017-10-01

    Full Text Available Maintenance of skeletal muscle mass is regulated by the balance between anabolic and catabolic processes. Mammalian target of rapamycin (mTOR is an evolutionarily conserved serine/threonine kinase, and is known to play vital roles in protein synthesis. Recent findings have continued to refine our understanding of the function of mTOR in maintaining skeletal muscle mass. mTOR controls the anabolic and catabolic signaling of skeletal muscle mass, resulting in the modulation of muscle hypertrophy and muscle wastage. This review will highlight the fundamental role of mTOR in skeletal muscle growth by summarizing the phenotype of skeletal-specific mTOR deficiency. In addition, the evidence that mTOR is a dual regulator of anabolism and catabolism in skeletal muscle mass will be discussed. A full understanding of mTOR signaling in the maintenance of skeletal muscle mass could help to develop mTOR-targeted therapeutics to prevent muscle wasting.

  1. Normal Weight but Low Muscle Mass and Abdominally Obese: Implications for the Cardiometabolic Risk Profile in Chronic Obstructive Pulmonary Disease.

    Science.gov (United States)

    Beijers, Rosanne J H C G; van de Bool, Coby; van den Borst, Bram; Franssen, Frits M E; Wouters, Emiel F M; Schols, Annemie M W J

    2017-06-01

    It is well established that low muscle mass affects physical performance in chronic obstructive pulmonary disease (COPD). We hypothesize that combined low muscle mass and abdominal obesity may also adversely influence the cardiometabolic risk profile in COPD, even in those with normal weight. The cardiometabolic risk profile and the responsiveness to 4 months high-intensity exercise training was assessed in normal-weight patients with COPD with low muscle mass stratified by abdominal obesity. This is a cross-sectional study including 81 clinically stable patients with COPD (age 62.5 ± 8.2 years; 50.6% males; forced expiratory volume in 1 second 55.1 ± 19.5 percentage predicted) with fat-free mass index risk profile. Triglycerides showed a significant decrease, while the HOMA-IR increased. Abdominal obesity is highly prevalent in normal-weight patients with COPD with low muscle mass who showed an increased cardiometabolic risk compared with patients without abdominal obesity. This cardiometabolic risk profile was not altered after 4 months of exercise training. Copyright © 2017 AMDA – The Society for Post-Acute and Long-Term Care Medicine. Published by Elsevier Inc. All rights reserved.

  2. High risk of malnutrition is associated with low muscle mass in older hospitalized patients - a prospective cohort study.

    Science.gov (United States)

    Pierik, Vincent D; Meskers, Carel G M; Van Ancum, Jeanine M; Numans, Siger T; Verlaan, Sjors; Scheerman, Kira; Kruizinga, Roeliene C; Maier, Andrea B

    2017-06-05

    Malnutrition, low muscle strength and muscle mass are highly prevalent in older hospitalized patients and associated with adverse outcomes. Malnutrition may be a risk factor for developing low muscle mass. We aimed to investigate the association between the risk of malnutrition and 1) muscle strength and muscle mass at admission and 2) the change of muscle strength and muscle mass during hospitalization in older patients. The EMPOWER study included 378 patients aged seventy years or older who were acutely or electively admitted to four different wards of an academic teaching hospital in Amsterdam. Patients were grouped into low risk of malnutrition and high risk of malnutrition based on the Short Nutritional Assessment Questionnaire (SNAQ) score and were assessed for hand grip strength and muscle mass using hand held dynamometry respectively bioelectrical impedance analysis (BIA) within 48 h after admission and at day seven, or earlier at the day of discharge. Muscle mass was expressed as skeletal muscle mass, appendicular lean mass, fat free mass and the skeletal muscle index. The mean age of the patients was 79.7 years (SD 6.39), 48.9% were female. At admission, being at high risk of malnutrition was significantly associated with lower muscle mass (Odds Ratio, 95% CI, 0.90, 0.85-0.96), but not with muscle strength. Muscle strength and muscle mass did not change significantly during hospitalization in both groups. In older hospitalized patients, a high risk of malnutrition is associated with lower muscle mass at admission, but not with muscle strength nor with change of either muscle strength or muscle mass during hospitalization.

  3. Influence on muscle oxygenation to EMG parameters at different skeletal muscle contraction

    Science.gov (United States)

    Zhang, Li; Song, Gaoqing

    2010-02-01

    The purpose of this study is to investigate the influence of muscle oxygenation on EMG parameters during isometric and incremental exercises and to observe the relationship between EMG parameters and muscle oxygenation. Twelve rowers took part in the tests. Near infrared spectrometer was utilized for measurements of muscle oxygenation on lateral quadriceps. sEMG measurement is performed for EMG parameters during isometric and incremental exercises. Results indicated that Oxy-Hb decrease significantly correlated with IEMG, E/T ratio and frequency of impulse signal during 1/3 MVC and 2/3 MVC isometric exercise, and it is also correlated with IEMG, E/T ratio and frequency of impulse signal. Increase of IEMG occurred at the time after Oxy-Hb decrease during incremental exercise and highly correlated with BLa. It is concluded that no matter how heavy the intensity is, Oxy-Hb dissociation may play an important role in affecting EMG parameters of muscle fatigue during isometric exercise. 2) EMG parameters may be influenced by Oxy-Hb dissociation and blood lactate concentration during dynamic exercise.

  4. Osteocalcin is necessary and sufficient to maintain muscle mass in older mice

    Directory of Open Access Journals (Sweden)

    Paula Mera

    2016-10-01

    Full Text Available Objective: A decrease in muscle protein turnover and therefore in muscle mass is a hallmark of aging. Because the circulating levels of the bone-derived hormone osteocalcin decline steeply during aging in mice, monkeys and humans we asked here whether this hormone might regulate muscle mass as mice age. Methods: We examined muscle mass and strength in mice lacking osteocalcin (Ocn−/− or its receptor in all cells (Gprc6a−/− or specifically in myofibers (Gprc6aMck−/− as well as in 9 month-old WT mice receiving exogenous osteocalcin for 28 days. We also examined protein synthesis in WT and Gprc6a−/− mouse myotubes treated with osteocalcin. Results: We show that osteocalcin signaling in myofibers is necessary to maintain muscle mass in older mice in part because it promotes protein synthesis in myotubes without affecting protein breakdown. We further show that treatment with exogenous osteocalcin for 28 days is sufficient to increase muscle mass of 9-month-old WT mice. Conclusion: This study uncovers that osteocalcin is necessary and sufficient to prevent age-related muscle loss in mice. Author Video: Author Video Watch what authors say about their articles Keywords: Osteocalcin, Muscle mass, Aging

  5. Improved skeletal muscle mass and strength after heavy strength training in very old individuals

    DEFF Research Database (Denmark)

    Bechshøft, Rasmus Leidesdorff; Malmgaard-Clausen, Nikolaj Mølkjær; Gliese, Bjørn

    2017-01-01

    , muscle fiber type distribution and size did not differ significantly between groups. We conclude that in protein supplemented very old individuals, heavy resistance training can increase muscle mass and strength, and that the relative improvement in mass is more pronounced when initial muscle mass is low.......Age-related loss of muscle mass and function represents personal and socioeconomic challenges. The purpose of this study was to determine the adaptation of skeletal musculature in very old individuals (83 + years) performing 12 weeks of heavy resistance training (3 ×/week) (HRT) compared to a non....... The increase in CSA is correlated inversely with the baseline level of CSA (R2 = 0.43, P muscle isometric strength, isokinetic peak torque and power increased significantly only in HRT by 10–15%, whereas knee extension one-repetition maximum (1 RM) improved by 91%. Physical functional tests...

  6. Skeletal muscle mass recovery from atrophy in IL-6 knockout mice.

    Science.gov (United States)

    Washington, T A; White, J P; Davis, J M; Wilson, L B; Lowe, L L; Sato, S; Carson, J A

    2011-08-01

    Skeletal muscle interleukin-6 (IL-6) expression is induced by continuous contraction, overload-induced hypertrophy and during muscle regeneration. The loss of IL-6 can alter skeletal muscle's growth and extracellular matrix remodelling response to overload-induced hypertrophy. Insulin-like growth factor-1 (IGF-1) gene expression and related signalling through Akt/mTOR is a critical regulator of muscle mass. The significance of IL-6 expression during the recovery from muscle atrophy is unclear. This study's purpose was to determine the effect of IL-6 loss on mouse gastrocnemius (GAS) muscle mass during recovery from hindlimb suspension (HS)-induced atrophy. Female C57BL/6 [wild type (WT)] and IL-6 knockout (IL-6 KO) mice at 10 weeks of age were assigned to control, HS or HS followed by normal cage ambulation groups. GAS muscle atrophy was induced by 10 days of HS. HS induced a 20% loss of GAS mass in both WT and IL-6 KO mice. HS+7 days of recovery restored WT GAS mass to cage-control values. GAS mass from IL-6 KO mice did not return to cage-control values until HS+14 days of recovery. Both IGF-1 mRNA expression and Akt/mTOR signalling were increased in WT muscle after 1 day of recovery. In IL-6 KO muscle, IGF-1 mRNA expression was decreased and Akt/mTOR signalling was not induced after 1 day of recovery. MyoD and myogenin mRNA expression were both induced in WT muscle after 1 day of recovery, but not in IL-6 KO muscle.   Muscle IL-6 expression appears important for the initial growth response during the recovery from disuse. © 2011 The Authors. Acta Physiologica © 2011 Scandinavian Physiological Society.

  7. Relation between body mass index percentile and muscle strength ...

    African Journals Online (AJOL)

    Noha Abdel Kader Abdel Kader Hasan

    2016-02-01

    Feb 1, 2016 ... Abstract Background: Muscle strength and endurance in children are very important to develop physical .... the Faculty of Physical Therapy, Cairo university, was used to ..... [9] Noelle G. Quantification of muscle fatigue in cerebral palsy and ... Bouckaert J. Physical fitness and physical activity in obese and.

  8. Association between healthy diet and exercise and greater muscle mass in older adults.

    Science.gov (United States)

    Kim, Jinhee; Lee, Yunhwan; Kye, Seunghee; Chung, Yoon-Sok; Kim, Kwang-Min

    2015-05-01

    To examine the association between healthy diet and exercise, individually and combined, and low muscle mass in older Korean adults. Population-based cross-sectional study from the Fourth and Fifth Korea National Health and Nutrition Examination Surveys from 2008 to 2011. Community. Nationally representative sample aged 65 and older (1,486 men, 1,799 women) in the Republic of Korea. A food frequency questionnaire was used to determine frequency of food group consumption (meat, fish, eggs, legumes; vegetables; fruits). Participation in exercise (aerobic and resistance) was based on self-report. Combined healthy lifestyle factors were calculated as the number of recommendations met regarding consumption of food groups and exercise performed. Appendicular skeletal muscle mass (ASM) was measured using dual-energy X-ray absorptiometry, and low muscle mass was defined using the variable of ASM adjusted for weight. Logistic regression analysis was performed to examine the association between healthy lifestyle factors and low muscle mass, adjusting for sociodemographic characteristics and health-related variables. In women, after controlling for covariates, vegetable consumption (odds ratio (OR)=0.52, 95% confidence interval (CI)=0.30-0.89) and aerobic exercise (OR=0.62, 95% CI=0.39-1.00) were inversely associated with low muscle mass. Also, the odds of low muscle mass was lower in women with three or more healthy lifestyle factors versus none (OR=0.45, 95% CI=0.23-0.87). In men, there were no associations between food group consumption and exercise and low muscle mass. Older women who exercise and consume a healthy diet have lower odds of low muscle mass. Engaging in multiple healthy behaviors may be important in preventing low muscle mass in late life. © 2015, Copyright the Authors Journal compilation © 2015, The American Geriatrics Society.

  9. Decreased muscle mass in Korean subjects with intracranial arterial stenosis: The Kangbuk Samsung Health Study.

    Science.gov (United States)

    Jung, Ho-Jung; Jung, Hwanseok; Lee, Taeyoung; Kim, Jongho; Park, Jongsin; Kim, Hacsoo; Cho, Junghwan; Lee, Won-Young; Park, Sung-Woo; Rhee, Eun-Jung; Oh, Hyung-Geun

    2017-01-01

    Intracranial arterial stenosis (ICAS) is a common cause of ischemic stroke in Asians. Decreased muscle mass is one of the major causes of chronic disease in adults. The purpose of this study was to analyze the relationship between muscle mass and ICAS in Korean adults. For this study, we selected a total of 10,530 participants (mean age, 43.3 years; 8558 men) in a health screening program, for whom transcranial Doppler (TCD) ultrasound was used to detect >50% ICAS based on criteria modified from the stroke outcomes and neuroimaging of intracranial atherosclerosis trial. Body composition was evaluated by bioelectrical impedance analysis (BIA). Skeletal muscle index (SMI) was calculated with muscle mass/weight (kg) * 100. Among the total patient population, 322 (3.1%) subjects had ICAS. Subjects with ICAS were older, and had higher mean values for fasting glucose, body mass index and blood pressure compared with those without ICAS. Subjects with ICAS had significantly lower muscle mass, SMI and higher percent body fat compared with those without ICAS. In logistic regression analysis, the subjects in the highest tertile of muscle mass had the lowest odds ratio for ICAS with the lowest tertile group of muscle mass as the reference group even after adjusting for age, systolic blood pressure, fasting blood glucose, sex, smoking and exercise (OR 0.650, 95% CI 0.442-0.955). Subjects with ICAS had significantly decreased muscle mass compared with those without ICAS in Korean adults. The risk for ICAS was lower in subjects with higher muscle mass. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  10. Muscle Structure Influences Utrophin Expression in mdx Mice

    Science.gov (United States)

    Banks, Glen B.; Combs, Ariana C.; Odom, Guy L.; Bloch, Robert J.; Chamberlain, Jeffrey S.

    2014-01-01

    Duchenne muscular dystrophy (DMD) is a severe muscle wasting disorder caused by mutations in the dystrophin gene. To examine the influence of muscle structure on the pathogenesis of DMD we generated mdx4cv:desmin double knockout (dko) mice. The dko male mice died of apparent cardiorespiratory failure at a median age of 76 days compared to 609 days for the desmin−/− mice. An ∼2.5 fold increase in utrophin expression in the dko skeletal muscles prevented necrosis in ∼91% of 1a, 2a and 2d/x fiber-types. In contrast, utrophin expression was reduced in the extrasynaptic sarcolemma of the dko fast 2b fibers leading to increased membrane fragility and dystrophic pathology. Despite lacking extrasynaptic utrophin, the dko fast 2b fibers were less dystrophic than the mdx4cv fast 2b fibers suggesting utrophin-independent mechanisms were also contributing to the reduced dystrophic pathology. We found no overt change in the regenerative capacity of muscle stem cells when comparing the wild-type, desmin−/−, mdx4cv and dko gastrocnemius muscles injured with notexin. Utrophin could form costameric striations with α-sarcomeric actin in the dko to maintain the integrity of the membrane, but the lack of restoration of the NODS (nNOS, α-dystrobrevin 1 and 2, α1-syntrophin) complex and desmin coincided with profound changes to the sarcomere alignment in the diaphragm, deposition of collagen between the myofibers, and impaired diaphragm function. We conclude that the dko mice may provide new insights into the structural mechanisms that influence endogenous utrophin expression that are pertinent for developing a therapy for DMD. PMID:24922526

  11. 52 Genetic Loci Influencing Myocardial Mass

    DEFF Research Database (Denmark)

    van der Harst, Pim; van Setten, Jessica; Verweij, Niek

    2016-01-01

    BACKGROUND: Myocardial mass is a key determinant of cardiac muscle function and hypertrophy. Myocardial depolarization leading to cardiac muscle contraction is reflected by the amplitude and duration of the QRS complex on the electrocardiogram (ECG). Abnormal QRS amplitude or duration reflect cha...

  12. Sarcopenia and Predictors of Skeletal Muscle Mass in Elderly Men With and Without Obesity

    Directory of Open Access Journals (Sweden)

    Katja Stoever MA

    2017-06-01

    Full Text Available Objectives: The aim of this study was to determine the variables which show the highest association with muscle mass and to identify the most important predictors for muscle mass in elderly men with and without sarcopenia. Methods: A total of 71 men participated, aged ≥65 years. Sarcopenia was assessed using the definition of the European Working Group on Sarcopenia in Older People with determining skeletal muscle index (SMI, hand-grip strength (HGS, and Short Physical Performance Battery. In addition, maximum strength at upper and lower extremities and physical activity were measured. Results: Strong correlations existed between SMI and gait speed, HGS, maximum isometric strength at leg and chest press. Physical activity showed low correlations with muscle strength. Regression analysis revealed HGS and gait speed as key predictors for SMI. Discussion: The recommendation is measuring gait speed and HGS in clinical practice at first followed by measuring muscle mass for determining sarcopenia.

  13. Delayed recovery of skeletal muscle mass following hindlimb immobilization in mTOR heterozygous mice.

    Directory of Open Access Journals (Sweden)

    Susan M Lang

    Full Text Available The present study addressed the hypothesis that reducing mTOR, as seen in mTOR heterozygous (+/- mice, would exaggerate the changes in protein synthesis and degradation observed during hindlimb immobilization as well as impair normal muscle regrowth during the recovery period. Atrophy was produced by unilateral hindlimb immobilization and data compared to the contralateral gastrocnemius. In wild-type (WT mice, the gradual loss of muscle mass plateaued by day 7. This response was associated with a reduction in basal protein synthesis and development of leucine resistance. Proteasome activity was consistently elevated, but atrogin-1 and MuRF1 mRNAs were only transiently increased returning to basal values by day 7. When assessed 7 days after immobilization, the decreased muscle mass and protein synthesis and increased proteasome activity did not differ between WT and mTOR(+/- mice. Moreover, the muscle inflammatory cytokine response did not differ between groups. After 10 days of recovery, WT mice showed no decrement in muscle mass, and this accretion resulted from a sustained increase in protein synthesis and a normalization of proteasome activity. In contrast, mTOR(+/- mice failed to fully replete muscle mass at this time, a defect caused by the lack of a compensatory increase in protein synthesis. The delayed muscle regrowth of the previously immobilized muscle in the mTOR(+/- mice was associated with a decreased raptor•4EBP1 and increased raptor•Deptor binding. Slowed regrowth was also associated with a sustained inflammatory response (e.g., increased TNFα and CD45 mRNA during the recovery period and a failure of IGF-I to increase as in WT mice. These data suggest mTOR is relatively more important in regulating the accretion of muscle mass during recovery than the loss of muscle during the atrophy phase, and that protein synthesis is more sensitive than degradation to the reduction in mTOR during muscle regrowth.

  14. Delayed recovery of skeletal muscle mass following hindlimb immobilization in mTOR heterozygous mice.

    Science.gov (United States)

    Lang, Susan M; Kazi, Abid A; Hong-Brown, Ly; Lang, Charles H

    2012-01-01

    The present study addressed the hypothesis that reducing mTOR, as seen in mTOR heterozygous (+/-) mice, would exaggerate the changes in protein synthesis and degradation observed during hindlimb immobilization as well as impair normal muscle regrowth during the recovery period. Atrophy was produced by unilateral hindlimb immobilization and data compared to the contralateral gastrocnemius. In wild-type (WT) mice, the gradual loss of muscle mass plateaued by day 7. This response was associated with a reduction in basal protein synthesis and development of leucine resistance. Proteasome activity was consistently elevated, but atrogin-1 and MuRF1 mRNAs were only transiently increased returning to basal values by day 7. When assessed 7 days after immobilization, the decreased muscle mass and protein synthesis and increased proteasome activity did not differ between WT and mTOR(+/-) mice. Moreover, the muscle inflammatory cytokine response did not differ between groups. After 10 days of recovery, WT mice showed no decrement in muscle mass, and this accretion resulted from a sustained increase in protein synthesis and a normalization of proteasome activity. In contrast, mTOR(+/-) mice failed to fully replete muscle mass at this time, a defect caused by the lack of a compensatory increase in protein synthesis. The delayed muscle regrowth of the previously immobilized muscle in the mTOR(+/-) mice was associated with a decreased raptor•4EBP1 and increased raptor•Deptor binding. Slowed regrowth was also associated with a sustained inflammatory response (e.g., increased TNFα and CD45 mRNA) during the recovery period and a failure of IGF-I to increase as in WT mice. These data suggest mTOR is relatively more important in regulating the accretion of muscle mass during recovery than the loss of muscle during the atrophy phase, and that protein synthesis is more sensitive than degradation to the reduction in mTOR during muscle regrowth.

  15. Deficits in muscle strength, mass, quality and mobility in people with chronic obstructive pulmonary disease

    DEFF Research Database (Denmark)

    Roig, Marc; Eng, Janice J; MacIntyre, Donna L

    2011-01-01

    PURPOSE: Midthigh intramuscular fat (IF), a feature of reduced muscle quality, is an important predictor of self-reported mobility loss in the elderly. This study compared measures of muscle strength, mass, IF, and mobility in patients with chronic obstructive pulmonary disease (COPD) and healthy...

  16. Levator claviculae muscle presenting as a hard clavicular mass: imaging study

    International Nuclear Information System (INIS)

    Ruiz Santiago, F.; Lopez Milena, G.; Tristan Fernandez, J.M.; Chamorro Santos, C.

    2001-01-01

    We report a case of levator claviculae muscle presenting clinically as a hard mass in the clavicular area due to angular deformity of this bone. To our knowledge, this is the first report where the anomalous muscle shows this clinical presentation. (orig.)

  17. Alterations in molecular muscle mass regulators after 8 days immobilizing Special Forces mission

    DEFF Research Database (Denmark)

    Jespersen, J. G.; Mikkelsen, Ulla Ramer; Nedergaard, A.

    2015-01-01

    In military operations, declined physical capacity can endanger the life of soldiers. During special support and reconnaissance (SSR) missions, Special Forces soldiers sustain 1-2 weeks full-body horizontal immobilization, which impairs muscle strength and performance. Adequate muscle mass and st...

  18. Immobilization/remobilization and the regulation of muscle mass

    Science.gov (United States)

    Almon, R. R.

    1983-01-01

    The relationship between animal body weight and the wet and dry weights of the soleus and EDL muscles was derived. Procedures were examined for tissue homogenization, fractionation, protein determination and DNA determination. A sequence of procedures and buffers were developed to carry out all analyses on one small muscle. This would yield a considerable increase in analytical strength associated with paired statistics. The proposed casting procedure which was to be used for immobilization was reexamined.

  19. The Impact of Low Muscle Mass Definition on the Prevalence of Sarcopenia in Older Australians

    Directory of Open Access Journals (Sweden)

    Solomon Yu

    2014-01-01

    Full Text Available Background. Sarcopenia is the presence of low muscle mass and low muscle function. The aim of this study was to establish cutoffs for low muscle mass using three published methods and to compare the prevalence of sarcopenia in older Australians. Methods. Gender specific cutoffs levels were identified for low muscle mass using three different methods. Low grip strength was determined using established cutoffs of <30 kg for men and <20 kg for women to estimate the prevalence of sarcopenia. Results. Gender specific cutoffs levels for low muscle mass identified were (a <6.89 kg/m2 for men and <4.32 kg/m2 for women, <2 standard deviation (SD of a young reference population; (b <7.36 kg/m2 for men and <5.81 kg/m2 for women from the lowest 20% percentile of the older group; and (c <−2.15 for men and <−1.42 for women from the lowest 20% of the residuals of linear regressions of appendicular skeletal mass, adjusted for fat mass and height. Prevalence of sarcopenia in older (65 years and older people by these three methods for men was 2.5%, 6.2%, and 6.4% and for women 0.3%, 9.3%, and 8.5%, respectively. Conclusions. Sarcopenia is common but consensus on the best method to confirm low muscle mass is required.

  20. Myostatin inhibition in muscle, but not adipose tissue, decreases fat mass and improves insulin sensitivity.

    Directory of Open Access Journals (Sweden)

    Tingqing Guo

    Full Text Available Myostatin (Mstn is a secreted growth factor expressed in skeletal muscle and adipose tissue that negatively regulates skeletal muscle mass. Mstn(-/- mice have a dramatic increase in muscle mass, reduction in fat mass, and resistance to diet-induced and genetic obesity. To determine how Mstn deletion causes reduced adiposity and resistance to obesity, we analyzed substrate utilization and insulin sensitivity in Mstn(-/- mice fed a standard chow. Despite reduced lipid oxidation in skeletal muscle, Mstn(-/- mice had no change in the rate of whole body lipid oxidation. In contrast, Mstn(-/- mice had increased glucose utilization and insulin sensitivity as measured by indirect calorimetry, glucose and insulin tolerance tests, and hyperinsulinemic-euglycemic clamp. To determine whether these metabolic effects were due primarily to the loss of myostatin signaling in muscle or adipose tissue, we compared two transgenic mouse lines carrying a dominant negative activin IIB receptor expressed specifically in adipocytes or skeletal muscle. We found that inhibition of myostatin signaling in adipose tissue had no effect on body composition, weight gain, or glucose and insulin tolerance in mice fed a standard diet or a high-fat diet. In contrast, inhibition of myostatin signaling in skeletal muscle, like Mstn deletion, resulted in increased lean mass, decreased fat mass, improved glucose metabolism on standard and high-fat diets, and resistance to diet-induced obesity. Our results demonstrate that Mstn(-/- mice have an increase in insulin sensitivity and glucose uptake, and that the reduction in adipose tissue mass in Mstn(-/- mice is an indirect result of metabolic changes in skeletal muscle. These data suggest that increasing muscle mass by administration of myostatin antagonists may be a promising therapeutic target for treating patients with obesity or diabetes.

  1. Prevalence of skeletal muscle mass loss and its association with swallowing function after cardiovascular surgery.

    Science.gov (United States)

    Wakabayashi, Hidetaka; Takahashi, Rimiko; Watanabe, Naoko; Oritsu, Hideyuki; Shimizu, Yoshitaka

    2017-06-01

    The aim of this study was to assess the prevalence of skeletal muscle mass loss and its association with swallowing function in patients with dysphagia after cardiovascular surgery. A retrospective cohort study was performed in 65 consecutive patients with dysphagia after cardiovascular surgery who were prescribed speech therapy. Skeletal muscle index (SMI) was calculated as total psoas muscle area assessed via abdominal computed tomography divided by height squared. Cutoff values were 6.36 cm 2 /m 2 for men and 3.92 cm 2 /m 2 for women. The Food Intake Level Scale (FILS) was used to assess the swallowing function. Univariate and ordered logistic regression analyses were applied to examine the associations between skeletal muscle mass loss and dysphagia. The study included 50 men and 15 women (mean age 73 ± 8 y). The mean SMI was 4.72 ± 1.37 cm 2 /m 2 in men and 3.33 ± 1.42 cm 2 /m 2 in women. Skeletal muscle mass loss was found in 53 (82%) patients. Twelve had tracheostomy cannula. Thirteen were non-oral feeding (FILS levels 1-3), 5 were oral food intake and alternative nutrition (levels 4-6), and 47 were oral food intake alone (levels 7-9) at discharge. The FILS at discharge was significantly lower in patients with skeletal muscle mass loss. Ordered logistic regression analysis of swallowing function showed that skeletal muscle mass loss and tracheostomy cannula were associated independently with the FILS at discharge. The prevalence of skeletal muscle mass loss is very high, and skeletal muscle mass loss is associated with swallowing function. Copyright © 2017 Elsevier Inc. All rights reserved.

  2. Adiposity, muscle mass and muscle strength in relation to functional decline in older persons.

    NARCIS (Netherlands)

    Schaap, L.A.; Koster, A.; Visser, M.

    2013-01-01

    Aging is associated with changes in body composition and muscle strength. This review aimed to determine the relation between different body composition measures and muscle strength measures and functional decline in older men and women. By use of relevant databases (PubMed, Embase, and CINAHL) and

  3. Total body skeletal muscle mass: estimation by creatine (methyl-d3) dilution in humans

    Science.gov (United States)

    Walker, Ann C.; O'Connor-Semmes, Robin L.; Leonard, Michael S.; Miller, Ram R.; Stimpson, Stephen A.; Turner, Scott M.; Ravussin, Eric; Cefalu, William T.; Hellerstein, Marc K.; Evans, William J.

    2014-01-01

    Current methods for clinical estimation of total body skeletal muscle mass have significant limitations. We tested the hypothesis that creatine (methyl-d3) dilution (D3-creatine) measured by enrichment of urine D3-creatinine reveals total body creatine pool size, providing an accurate estimate of total body skeletal muscle mass. Healthy subjects with different muscle masses [n = 35: 20 men (19–30 yr, 70–84 yr), 15 postmenopausal women (51–62 yr, 70–84 yr)] were housed for 5 days. Optimal tracer dose was explored with single oral doses of 30, 60, or 100 mg D3-creatine given on day 1. Serial plasma samples were collected for D3-creatine pharmacokinetics. All urine was collected through day 5. Creatine and creatinine (deuterated and unlabeled) were measured by liquid chromatography mass spectrometry. Total body creatine pool size and muscle mass were calculated from D3-creatinine enrichment in urine. Muscle mass was also measured by magnetic resonance imaging (MRI), dual-energy x-ray absorptiometry (DXA), and traditional 24-h urine creatinine. D3-creatine was rapidly absorbed and cleared with variable urinary excretion. Isotopic steady-state of D3-creatinine enrichment in the urine was achieved by 30.7 ± 11.2 h. Mean steady-state enrichment in urine provided muscle mass estimates that correlated well with MRI estimates for all subjects (r = 0.868, P creatine dose determined by urine D3-creatinine enrichment provides an estimate of total body muscle mass strongly correlated with estimates from serial MRI with less bias than total lean body mass assessment by DXA. PMID:24764133

  4. Influence of Unweighting on Insulin Signal Transduction in Muscle

    Science.gov (United States)

    Tischler, Marc E.

    2002-01-01

    Unweighting of the juvenile soleus muscle is characterized by an increased binding capacity for insulin relative to muscle mass due to sparing of the receptors during atrophy. Although carbohydrate metabolism and protein degradation in the unweighted muscle develop increased sensitivity to insulin in vivo, protein synthesis in vivo and system A amino acid transport in vitro do not appear to develop such an enhanced response. The long-term goal is to identify the precise nature of this apparent resistance in the insulin signal transduction pathway and to consider how reduced weight-bearing may elicit this effect, by evaluating specific components of the insulin signalling pathway. Because the insulin-signalling pathway has components in common with the signal transduction pathway for insulin-like growth factor (IGF-1) and potentially other growth factors, the study could have important implications in the role of weight-bearing function on muscle growth and development. Since the insulin signalling pathway diverges following activation of insulin receptor tyrosine kinase, the immediate specific aims will be to study the receptor tyrosine kinase (IRTK) and those branches, which lead to phosphorylation of insulin receptor substrate-1 (IRS-1) and of Shc protein. To achieve these broader objectives, we will test in situ, by intramuscular injection, the responses of glucose transport, system A amino acid transport and protein synthesis to insulin analogues for which the receptor has either a weaker or much stronger binding affinity compared to insulin. Studies will include: (1) estimation of the ED(sub 50) for each analogue for these three processes; (2) the effect of duration (one to four days) of unweighting on the response of each process to all analogues tested; (3) the effect of unweighting and the analogues on IRTK activity; and (4) the comparative effects of unweighting and analogue binding on the tyrosine phosphorylation of IRTK, IRS-1, and Shc protein.

  5. The Effects of Muscle Mass on Homocyst(e)ine Levels in Plasma and Urine.

    Science.gov (United States)

    Malinow, M René; Lister, Craig L; DE Crée, Carl

    The present study was designed to examine the relationship between homocyst(e)ine (H[e]) levels and muscle mass. Two experimental groups each of 24 Caucasian males, one consisting of higher-muscle mass subjects (HMM) and the other of lower-muscle mass subjects (LMM) participated in this study. Muscle mass was estimated from 24-hour urine collections of creatinine (Crt). Muscle mass was 40.3 ± 15.9 kg in HMM and 37.2 ± 11.4 kg in LMM (P= 0.002). Mean plasma H(e) levels in HMM were 10.29 ± 2.9 nmol/mL, and in LMM were 10.02 ± 2.4 nmol/L (Not significant, [NS]). Urinary H(e) levels (UH[e]) were 9.95 ± 4.3 nmol/mL and 9.22 ± 2.9 nmol/mL for HMM and LMM, respectively (NS). Plasma H(e) levels correlated well with UH(e) (HMM: r= 0.58, P= 0.009; LMM: r= 0.66, P= 0.004). Muscle mass and was not correlated to either plasma H(e) or UH(e). However, in HMM trends were identified for body mass to be correlated with UH(e) (r= 0.39, P= 0.10) and UCrt (r= 0.41, P= 0.08). Surprisingly, in HMM plasma and UCrt were only weakly correlated (r= 0.44, P= 0.06). Our results do not support a causal relationship between the amount of muscle mass and H(e) levels in plasma or urine.

  6. Effect of Body Mass Index on Postural Balance and Muscle Strength in Children Aged 8-10 years

    Directory of Open Access Journals (Sweden)

    Lucky Prasetiowati

    2017-04-01

    Full Text Available Background:Childhood overweight and obesity, which are considered as global epidemic, can be assessed using Body Mass Index (BMI. BMI difference can lead to anatomic changes due to an increased body load. This increase might also affect motor performance, including changes in postural balance and muscle strength. Aims and Objectives: to explain the influence of BMI on postural balance and lower limb muscle strength and to assess the correlation between those two variables in children aged 8-10 years. Material and methods:The sample consisted of 63 children aged 8-10 years, which were divided in 3 groups: BMI-normal, BMI-overweight, and BMI-obese. The postural balance was assessed using single leg balance test on MatScan and the Center Of Pressure (COP area was recorded. Isometric muscle strength of hip extensor and knee extensor were measured using a hand-held dynamometer. Results: Obese children had significantly largerCOP area than overweight (p = 0.004 and normal weight children (p = 0.000.There were no significant differences in hip extensor muscle strength between obese children with overweight and normal weight children (p=0.527. The absolute knee extensor muscle strength in obese group was significantly higher than the overweight and normal group (p = 0.003. However the relative muscle strength of lower limb for obese children was significantly lower than for normal weight. There was no significant correlation between absolute hip extensor and knee extensor muscles strength with COP area. Conclusion: Obese children have decreased postural balance and increased absolute knee extensormuscle strength significantly when compared to overweight and normal children. There is no significant correlation between postural balance and muscle strength.

  7. Variability in muscle dysmorphia symptoms: the influence of weight training.

    Science.gov (United States)

    Thomas, Liam S; Tod, David A; Lavallee, David E

    2011-03-01

    The purpose of this study was to examine the influence of a weight training session on muscle dysmorphia symptoms in young men who regularly weight trained. Using a within-subjects crossover design, 30 men (mean ± SD; 20.93 ± 2.60 years, 86.87 ± 10.59 kg, and 1.76 ± 0.01 m) were randomly allocated to 1 of 2 groups, and completed the Muscle Dysmorphic Disorder Inventory twice, once each on 2 separate days. One day 1, group 1 completed the questionnaire after a weight training session and group 2 on a rest day. One day 2, group 1 completed the questionnaire on a rest day and group 2 after a weight training session. The mean score for drive for size was significantly higher on a rest day (18.00) than on a training day (15.87; p = 0.001, d = 1.03). The mean score for appearance intolerance was significantly higher on a rest day (10.10) compared with that on a training day (8.97; p = 0.001, d = 0.69). The mean score for functional impairment was significantly higher on a rest day (10.20) than on a training day (9.47; p = 0.037, d = 0.40). These results provide evidence that muscle dysmorphia symptoms have state-like properties and may be influenced by situational variables. The results may indicate that strength and conditioning specialists and mental health professionals need to observe clients over time and take into account environmental variables before making decisions about the presence or absence of the condition.

  8. Influence of exercise contraction mode and protein supplementation on human skeletal muscle satellite cell content and muscle fiber growth

    DEFF Research Database (Denmark)

    Farup, Jean; Rahbek, Stine Klejs; Riis, Simon

    2014-01-01

    -specific association between emergence of satellite cells (SCs), muscle growth, and remodeling in response to 12 wk unilateral resistance training performed as eccentric (Ecc) or concentric (Conc) resistance training ± whey protein (Whey, 19.5 g protein + 19.5 g glucose) or placebo (Placebo, 39 g glucose......Skeletal muscle satellite cells (SCs) are involved in remodeling and hypertrophy processes of skeletal muscle. However, little knowledge exists on extrinsic factors that influence the content of SCs in skeletal muscle. In a comparative human study, we investigated the muscle fiber type......) supplementation. Muscle biopsies (vastus lateralis) were analyzed for fiber type-specific SCs, myonuclei, and fiber cross-sectional area (CSA). Following training, SCs increased with Conc in both type I and type II fibers (P

  9. The impact of low muscle mass definition on the prevalence of sarcopenia in older Australians.

    Science.gov (United States)

    Yu, Solomon; Appleton, Sarah; Adams, Robert; Chapman, Ian; Wittert, Gary; Visvanathan, Thavarajah; Visvanathan, Renuka

    2014-01-01

    Sarcopenia is the presence of low muscle mass and low muscle function. The aim of this study was to establish cutoffs for low muscle mass using three published methods and to compare the prevalence of sarcopenia in older Australians. Gender specific cutoffs levels were identified for low muscle mass using three different methods. Low grip strength was determined using established cutoffs of standard deviation (SD) of a young reference population; (b) <7.36 kg/m(2) for men and <5.81 kg/m(2) for women from the lowest 20% percentile of the older group; and (c) <-2.15 for men and <-1.42 for women from the lowest 20% of the residuals of linear regressions of appendicular skeletal mass, adjusted for fat mass and height. Prevalence of sarcopenia in older (65 years and older) people by these three methods for men was 2.5%, 6.2%, and 6.4% and for women 0.3%, 9.3%, and 8.5%, respectively. Sarcopenia is common but consensus on the best method to confirm low muscle mass is required.

  10. Mechanistic Links Underlying the Impact of C-Reactive Protein on Muscle Mass in Elderly

    Directory of Open Access Journals (Sweden)

    Britta Wåhlin-Larsson

    2017-11-01

    Full Text Available Background/Aims: Mechanisms underlying the relationship between systemic inflammation and age-related decline in muscle mass are poorly defined. The purpose of this work was to investigate the relationship between the systemic inflammatory marker CRP and muscle mass in elderly and to identify mechanisms by which CRP mediates its effects on skeletal muscle, in-vitro. Methods: Muscle mass and serum CRP level were determined in a cohort of 118 older women (67±1.7 years. Human muscle cells were differentiated into myotubes and were exposed to CRP. The size of myotubes was determined after immunofluorescent staining using troponin. Muscle protein synthesis was assessed using stable isotope tracers and key signalling pathways controlling protein synthesis were determined using western-blotting. Results: We observed an inverse relationship between circulating CRP level and muscle mass (β= -0.646 (95% CI: -0.888, -0.405 p<0.05 and demonstrated a reduction (p < 0.05 in the size of human myotubes exposed to CRP for 72 h. We next showed that this morphological change was accompanied by a CRP-mediated reduction (p < 0.05 in muscle protein fractional synthetic rate of human myotubes exposed to CRP for 24 h. We also identified a CRP-mediated increased phosphorylation (p<0.05 of regulators of cellular energy stress including AMPK and downstream targets, raptor and ACC-β, together with decreased phosphorylation of Akt and rpS6, which are important factors controlling protein synthesis. Conclusion: This work established for the first time mechanistic links by which chronic elevation of CRP can contribute to age-related decline in muscle function.

  11. Locomotion and muscle mass measures in a murine model of collagen-induced arthritis

    NARCIS (Netherlands)

    Hartog, A.; Hulsman, J.; Garssen, J.

    2009-01-01

    Background: Rheumatoid arthritis (RA) is characterized by chronic poly-arthritis, synovial hyperplasia, erosive synovitis, progressive cartilage and bone destruction accompanied by a loss of body cell mass. This loss of cell mass, known as rheumatoid cachexia, predominates in the skeletal muscle and

  12. Influence of Lower Extremity Muscle Size and Quality on Stair-Climb Performance in Career Firefighters.

    Science.gov (United States)

    Kleinberg, Craig R; Ryan, Eric D; Tweedell, Andrew J; Barnette, Timothy J; Wagoner, Chad W

    2016-06-01

    The purpose of this study was to examine the influence of lower extremity muscular size and quality on stair-climb performance (SCP) in career firefighters. Forty-six male career firefighters (age = 37.0 ± 7.2 years; stature = 180.2 ± 6.9 cm; body mass = 108.0 ± 19.8 kg) volunteered for this study. Panoramic ultrasound images of the vastus lateralis and rectus femoris were obtained to determine cross-sectional area (CSA) and echo intensity (EI) of each muscle. The CSA of each muscle was then summed together and normalized to body mass (CSA/BM [QCSA]). Additionally, EI was averaged across both muscles (QEI). Participants then performed a timed and weighted SCP assessment where they ascended and descended 26 stairs 4 times as quickly as possible while wearing a weighted vest (22.73 kg) to simulate the weight of their self-contained breathing apparatus and turnout gear. Bivariate correlations and stepwise regression analyses were used to examine the relationships among variables and the relative contributions of QCSA and QEI to SCP. Partial correlations were used to examine the relationship between QCSA and SCP and QEI and SCP while controlling for age and body mass index (BMI). The results indicated that QCSA and QEI were significantly related to SCP before (r = -0.492, p = 0.001; r = 0.363, p = 0.013, respectively) and after accounting for age and BMI (r = -0.324, p = 0.032; r = 0.413, p = 0.005, respectively). Both QCSA and QEI contributed significantly to the prediction of SCP (r = 0.560, p < 0.001). These findings indicate that lower extremity muscle size and quality are important contributors to critical firefighting tasks, which have been shown to be improved with resistance training.

  13. Peak muscle mass in young men and sarcopenia in the ageing male

    DEFF Research Database (Denmark)

    Nielsen, Morten Frost Munk; Nielsen, T L; Brixen, K

    2015-01-01

    of sarcopenia in men. INTRODUCTION: The ageing population increases the prevalence of sarcopenia. Estimation of normative data on muscle mass in young men during the peak of anabolic hormones is necessary for the diagnosis of sarcopenia in ageing males. The purposes of this study were to provide population......The prevalence of sarcopenia increases with age. The diagnosis of sarcopenia relies in part on normative data on muscle mass, but these data are lacking. This study provides population-based reference data on muscle mass in young men, and these results may be used clinically for the diagnosis......-based reference data on lean body mass (LBM) in young men during the time of peak levels of GH/IGF-1 and testosterone and further to apply the reference data on a population-based sample of men aged 60-74 years to estimate the prevalence of sarcopenia. METHODS: This is a cross-sectional, population-based single...

  14. Growth hormone mitigates loss of periosteal bone formation and muscle mass in disuse osteopenic rats.

    Science.gov (United States)

    Grubbe, M-C; Thomsen, J S; Nyengaard, J R; Duruox, M; Brüel, A

    2014-12-01

    Growth hormone (GH) is a potent anabolic agent capable of increasing both bone and muscle mass. The aim was to investigate whether GH could counteract disuse-induced loss of bone and muscle mass in a rat model. Paralysis was induced by injecting 4 IU Botox (BTX) into the muscles of the right hind limb. Sixty female Wistar rats, 14 weeks old, were divided into the following groups: baseline, controls, BTX, BTX+GH, and GH. GH was given at a dosage of 5 mg/kg/d for 4 weeks. Compared with controls, BTX resulted in lower periosteal bone formation rate (BFR/BS,-79%, Pbone mineral density (aBMD, -13%, Pbone volume (BV/TV, -26%, Pbone strength (-12%, Pbone strength was found. In addition, GH partly prevented loss of muscle mass (+29% vs. BTX, P<0.001), and tended to prevent loss of muscle CSA (+11%, P=0.064). In conclusion, GH mitigates disuse-induced loss of periosteal BFR/BS at the mid-femur and rectus femoris muscle mass.

  15. Ultrasonography to Measure Swallowing Muscle Mass and Quality in Older Patients With Sarcopenic Dysphagia.

    Science.gov (United States)

    Ogawa, Nami; Mori, Takashi; Fujishima, Ichiro; Wakabayashi, Hidetaka; Itoda, Masataka; Kunieda, Kenjiro; Shigematsu, Takashi; Nishioka, Shinta; Tohara, Haruka; Yamada, Minoru; Ogawa, Sumito

    2018-06-01

    Sarcopenic dysphagia is characterized by difficulty swallowing due to a loss of whole-body skeletal and swallowing muscle mass and function. However, no study has reported on swallowing muscle mass and quality in patients with sarcopenic dysphagia. To compare the differences in swallowing muscle mass and quality between sarcopenic and nonsarcopenic dysphagia. A cross-sectional study was performed in 55 older patients, who had been recommended to undergo dysphagia assessment and/or rehabilitation. Sarcopenic dysphagia was diagnosed using a diagnostic algorithm for sarcopenic dysphagia. The thickness and area of tongue muscle and geniohyoid muscle (coronal plane and sagittal plane), and the echo-intensity of the tongue and geniohyoid muscles were examined by ultrasound. The study participants included 31 males and 24 females (mean age of 82 ± 7 years), with 14 having possible sarcopenic dysphagia, 22 probable sarcopenic dysphagia, and 19 without sarcopenic dysphagia. The group with sarcopenic dysphagia had a significantly lower cross-sectional area and area of brightness of the tongue muscle than that observed in the group without sarcopenic dysphagia. The most specific factor for identifying the presence of sarcopenic dysphagia was tongue muscle area (sensitivity, 0.389; specificity, 0.947; cut-off value, 1536.0), while the factor with the highest sensitivity was geniohyoid muscle area brightness in sagittal sections (sensitivity, 0.806; specificity, 0.632; cut-off value, 20.1). Multivariate logistic regression analysis showed that the area of the tongue muscle and its area of brightness were independent risk factors for sarcopenic dysphagia. However, geniohyoid sagittal muscle area and area of brightness showed no significant independent association with sarcopenic dysphagia. Tongue muscle mass in patients with sarcopenic dysphagia was smaller than that in patients without the condition. Sarcopenic dysphagia was also associated with increased intensity of the

  16. Tinetti mobility test is related to muscle mass and strength in non-institutionalized elderly people.

    Science.gov (United States)

    Curcio, Francesco; Basile, Claudia; Liguori, Ilaria; Della-Morte, David; Gargiulo, Gaetano; Galizia, Gianluigi; Testa, Gianluca; Langellotto, Assunta; Cacciatore, Francesco; Bonaduce, Domenico; Abete, Pasquale

    2016-12-01

    Elderly people are characterized by a high prevalence of falls and sarcopenia. However, the relationship among Tinetti mobility test (TMT) score, a powerful tool to detect elderly people at risk of falls, and sarcopenia is still not thoroughly investigated. Thus, to determine the relationship between TMT score and muscle mass and strength, 337 elderly participants (mean age 77.1 ± 6.9 years) admitted to comprehensive geriatric assessment were enrolled. TMT score, muscle mass by bioimpedentiometer, and muscle strength by grip strength were evaluated. Muscle mass progressively decreased as TMT score decreased (from 15.3 ± 3.7 to 8.8 ± 1.8 kg/m 2 ; p for trend strength decreased progressively as Tinetti score decreased (from 34.7 ± 8.0 to 23.7 ± 8.7 kg; p for trend 0.001). Linear regression analysis demonstrated that TMT score is linearly related with muscle mass (y = 4.5x + 0.4, r = 0.61; p strength (y = 14.0x + 0.8, r = 0.53; p strength (r = 0.39, p = 0.046). The present study indicates that TMT score is significantly related to muscle mass and strength in non-institutionalized elderly participants. This evidence suggests that TMT score, together with evaluation of muscle mass and strength, may identify sarcopenic elderly participants at high risk of falls.

  17. Effect of anabolic steroids on skeletal muscle mass during hindlimb suspension

    Science.gov (United States)

    Tsika, R. W.; Herrick, R. E.; Baldwin, K. M.

    1987-01-01

    The effect of treatment with an anabolic steroid (nandrolone decanoate) on the muscle mass of plantaris and soleus of a rats in hindlimb suspension, and on the isomyosin expression in these muscles, was investigated in young female rats divided into four groups: normal control (NC), normal steroid (NS), normal suspension (N-sus), and suspension steroid (sus-S). Steroid treatment of suspended animals (sus-S vs N-sus) was found to partially spare body weight and muscle weight, as well as myofibril content of plantaris (but not soleus), but did not modify the isomyosin pattern induced by suspension. In normal rats (NS vs NC), steroid treatment did enhance body weight and plantaris muscle weight; the treatment did not alter isomyosin expression in either muscle type.

  18. Low muscle mass--tall and obese children a special genre of obesity.

    Science.gov (United States)

    Ralt, Dina

    2007-01-01

    The prevalence of over-weight and obesity has increased markedly in the last two decades and vast international resources have been directed toward researching these issues. Obesity would appear to be a problem that is easy to resolve: just eat less and move more. However, this very common condition has turned out to be extremely troublesome, and in some cases even insolvable. A perspective is presented here suggesting that some of the insoluble cases of obesity are the result of an inborn condition of a very low muscle mass. The interplay between less muscle and more fat tissue is discussed from physiological and environmental perspectives with an emphasis on the early years of childhood. It is proposed that these interactions lead to bodily economic decisions sliding between thrift or prodigal strategies. The thrift strategy results not only in obesity and less physical activity but also in other maladies which the body is unable to manage. What leads to obesity (less muscle, more fat) in the medial population will result in morbid obesity when the children are short of muscle tissue from the start. Attempts to lessen the consequences of low muscle mass, which might be very difficult at adulthood, can be more fruitful if initiated at childhood. Early recognition of the ailment is thus crucial. Based on studies demonstrating a 'rivalry' between muscle build-up and height growth at childhood, it is postulated that among the both taller and more obese children the percentage of children with lower muscle mass will be significant. A survey of the height and BMI (Body Mass Index) of Israeli fifth graders supports this postulation. A special, body/muscle-building gymnastics program for children is suggested as a potential early intervention to partially prevent this type of almost irreversible ill progress of obesity.

  19. Delayed Recovery of Skeletal Muscle Mass following Hindlimb Immobilization in mTOR Heterozygous Mice

    OpenAIRE

    Lang, Susan M.; Kazi, Abid A.; Hong-Brown, Ly; Lang, Charles H.

    2012-01-01

    The present study addressed the hypothesis that reducing mTOR, as seen in mTOR heterozygous (+/-) mice, would exaggerate the changes in protein synthesis and degradation observed during hindlimb immobilization as well as impair normal muscle regrowth during the recovery period. Atrophy was produced by unilateral hindlimb immobilization and data compared to the contralateral gastrocnemius. In wild-type (WT) mice, the gradual loss of muscle mass plateaued by day 7. This response was associated ...

  20. Impaired physical function, loss of muscle mass and assessment of biomechanical properties in critical ill patients

    DEFF Research Database (Denmark)

    Poulsen, Jesper Brøndum

    2012-01-01

    Intensive care unit (ICU) admission is associated with muscle weakness and ICU survivors report sustained limitation of physical capacity for years after discharge. Limited information is available on the underlying biomechanical properties responsible for this muscle function impairment. A plaus......Intensive care unit (ICU) admission is associated with muscle weakness and ICU survivors report sustained limitation of physical capacity for years after discharge. Limited information is available on the underlying biomechanical properties responsible for this muscle function impairment....... A plausible contributor to the accentuated catabolic drive in ICU patients is a synergistic response to inflammation and inactivity leading to loss of muscle mass. As these entities are predominantly present in the early phase of ICU stay, interventions employed during this time frame may exhibit the greatest...... potential to counteract loss of muscle mass. Despite the obvious clinical significance of muscle atrophy for the functional impairment observed in ICU survivors, no preventive therapies have been identified as yet. The overall aim of the present dissertation is to characterize aspects of physical function...

  1. The loss of skeletal muscle strength, mass, and quality in older adults : the health, aging and body composition study

    NARCIS (Netherlands)

    Goodpaster, Bret H; Park, Seok Won; Harris, Tamara B; Kritchevsky, Steven B; Nevitt, Michael; Schwartz, Ann V; Simonsick, Eleanor M; Tylavsky, Frances A; Visser, Marjolein; Newman, Anne B

    2006-01-01

    BACKGROUND: The loss of muscle mass is considered to be a major determinant of strength loss in aging. However, large-scale longitudinal studies examining the association between the loss of mass and strength in older adults are lacking. METHODS: Three-year changes in muscle mass and strength were

  2. Creatinine excretion rate, a marker of muscle mass, is related to clinical outcome in patients with chronic systolic heart failure

    NARCIS (Netherlands)

    ter Maaten, Jozine M.; Damman, Kevin; Hillege, Hans L.; Bakker, Stephan J.; Anker, Stefan D.; Navis, Gerjan; Voors, Adriaan A.

    2014-01-01

    Aims In chronic heart failure (CHF), low body mass as a reflection of low muscle mass has been associated with poor outcome. Urinary creatinine excretion rate (CER) is an established marker of muscle mass, but has not been investigated in CHF. This study aims to evaluate urinary CER as a marker of

  3. Relative Skeletal Muscle Mass Is Associated with Development of Metabolic Syndrome

    Directory of Open Access Journals (Sweden)

    Byung Sam Park

    2013-12-01

    Full Text Available BackgroundVisceral adiposity is related to insulin resistance. Skeletal muscle plays a central role in insulin-mediated glucose disposal; however, little is known about the association between muscle mass and metabolic syndrome (MS. This study is to clarify the clinical role of skeletal muscle mass in development of MS.MethodsA total of 1,042 subjects were enrolled. Subjects with prior MS and chronic diseases were excluded. After 24 months, development of MS was assessed using NCEP-ATP III criteria. Skeletal muscle mass (SMM; kg, body fat mass (BFM; kg, and visceral fat area (VFA; cm2 were obtained from bioelectrical analysis. Then, the following values were calculated as follows: percent of SMM (SMM%; %: SMM (kg/weight (kg, skeletal muscle index (SMI; kg/m2: SMM (kg/height (m2, skeletal muscle to body fat ratio (MFR: SMM (kg/BFM (kg, and skeletal muscle to visceral fat ratio (SVR; kg/cm2: SMM (kg/VFA (cm2.ResultsAmong 838 subjects, 88 (10.5% were newly diagnosed with MS. Development of MS increased according to increasing quintiles of BMI, SMM, VFA, and SMI, but was negatively associated with SMM%, MFR, and SVR. VFA was positively associated with high waist circumference (WC, high blood pressure (BP, dysglycemia, and high triglyceride (TG. In contrast, MFR was negatively associated with high WC, high BP, dysglycemia, and high TG. SVR was negatively associated with all components of MS.ConclusionRelative SMM ratio to body composition, rather than absolute mass, may play a critical role in development of MS and could be used as a strong predictor.

  4. The influence of strenuous muscle stimulation on the menarche.

    Science.gov (United States)

    Yabuuchi, F; Ichikawa, Y; Arakawa, M; Chiba, G

    1984-03-01

    Nowadays, the average age at which menarche begins is lowering by three to four years every century, that is, four months every decade, according to both Japanese, and European and American annual changes of the average age. It emerged that the menarche shows a tendency to occur later in female gymnasts, because of the influence of strenuous muscle stimulation, and the fact that a higher level of technic is required in gymnastic games each year. These conclusions have been drawn from replies submitted to a questionnaire distributed among a relatively small number of gymnasts who participated in the competitions including the Inter High School Championship and the World Cup Championship. For example, at the age of 14, the percentage of women who had menstruated is almost 100% among women in general, but only 24% among World Cup Championship gymnasts, the average age at menarche of the latter being later than that of the former by as many as 3 years. At the age of 16, the percentage of women who had menstruated is 100% among women in general, but on the other hand, it is only 60% among World Cup Championship gymnasts, in other words, only a low percentage of women, of the latter group, had menstruated. Finally in our study, we established that the age at menarche of gymnasts is three or five years later than that of women in general. From our study, we concluded that the excessive burden imposed on muscles might cause an abnormal menstrual cycle, and the influence on menstruation would be considerable.

  5. Within-Winter Flexibility in Muscle Masses, Myostatin, and Cellular Aerobic Metabolic Intensity in Passerine Birds.

    Science.gov (United States)

    Swanson, David L; King, Marisa O; Culver, William; Zhang, Yufeng

    Metabolic rates of passerine birds are flexible traits that vary both seasonally and among and within winters. Seasonal variation in summit metabolic rates (M sum = maximum thermoregulatory metabolism) in birds is consistently correlated with changes in pectoralis muscle and heart masses and sometimes with variation in cellular aerobic metabolic intensity, so these traits might also be associated with shorter-term, within-winter variation in metabolic rates. To determine whether these mechanisms are associated with within-winter variation in M sum , we examined the effects of short-term (ST; 0-7 d), medium-term (MT; 14-30 d), and long-term (LT; 30-yr means) temperature variables on pectoralis muscle and heart masses, pectoralis expression of the muscle-growth inhibitor myostatin and its metalloproteinase activators TLL-1 and TLL-2, and pectoralis and heart citrate synthase (CS; an indicator of cellular aerobic metabolic intensity) activities for two temperate-zone resident passerines, house sparrows (Passer domesticus) and dark-eyed juncos (Junco hyemalis). For both species, pectoralis mass residuals were positively correlated with ST temperature variables, suggesting that cold temperatures resulted in increased turnover of pectoralis muscle, but heart mass showed little within-winter variation for either species. Pectoralis mRNA and protein expression of myostatin and the TLLs were only weakly correlated with ST and MT temperature variables, which is largely consistent with trends in muscle masses for both species. Pectoralis and heart CS activities showed weak and variable trends with ST temperature variables in both species, suggesting only minor effects of temperature variation on cellular aerobic metabolic intensity. Thus, neither muscle or heart masses, regulation by the myostatin system, nor cellular aerobic metabolic intensity varied consistently with winter temperature, suggesting that other factors regulate within-winter metabolic variation in these birds.

  6. Artistic versus rhythmic gymnastics: effects on bone and muscle mass in young girls.

    Science.gov (United States)

    Vicente-Rodriguez, G; Dorado, C; Ara, I; Perez-Gomez, J; Olmedillas, H; Delgado-Guerra, S; Calbet, J A L

    2007-05-01

    We compared 35 prepubertal girls, 9 artistic gymnasts and 13 rhythmic gymnasts with 13 nonphysically active controls to study the effect of gymnastics on bone and muscle mass. Lean mass, bone mineral content and areal density were measured by dual energy X-ray absorptiometry, and physical fitness was also assessed. The artistic gymnasts showed a delay in pubertal development compared to the other groups (partistic gymnasts had a 16 and 17 % higher aerobic power and anaerobic capacity, while the rhythmic group had a 14 % higher anaerobic capacity than the controls, respectively (all partistic gymnasts had higher lean mass (partistic and the rhythmic gymnasts (partistic group compared to the other groups. Lean mass strongly correlated with bone mineral content (r=0.84, partistic gymnastic participation is associated with delayed pubertal development, enhanced physical fitness, muscle mass, and bone density in prepubertal girls, eliciting a higher osteogenic stimulus than rhythmic gymnastic.

  7. Rainfall influence on styles of mass movement

    Science.gov (United States)

    Anderson, S. P.; Rengers, F. K.; Foster, M. A.; Winchell, E. W.; Anderson, R. S.

    2017-12-01

    Precipitation characteristics influence whether hillslope materials move in rain-splash driven hops, shallow landslides, or in deep-seated failures. While one might expect a particular style of slope failure to dominate in a region, we report on multiple distinctive mass movements on a single ridge, each associated with different weather events. This suggests that understanding climate regulation of denudation rates and hillslope morphology requires quantifying both triggering hydro-climates, and the corresponding hillslope response to the full spectrum of events. We explore these connections on Dakota Ridge, a hogback at the eastern margin of the Colorado Front Range. The dipslope of Dakota Ridge has generated slumps, debris flows, and an earthflow over the last 4 years; Pleistocene-era deep-seated landslides are also evident. We document mass-movements along a 1 km long segment of Dakota Ridge. Weeklong precipitation and flooding in September 2013 produced slumps, each of which displaced 50-100 m3 of mobile regolith several meters downslope, and some of which triggered shallow, relatively non-erosive debris flows. By contrast, a similar precipitation total over the month of May 2015 mobilized an earthflow. The 10 m wide earthflow displaced mobile regolith downslope as much as 10 m over its 150 m length. These recent landslides are dwarfed by a 400 m wide deep-seated landslide that controls slope morphology from ridge crest to toe. Exposure ages (10Be) suggest a late-Pleistocene age for this feature. Although the September 2013 storm produced record-setting rainfall totals at daily, monthly and annual timescales (e.g., annual exceedance probability of <1/1000 for daily totals), the failures from that event, while numerous, were the smallest of all the landslides in the study area. These observations raise the question: what hydro-climatic conditions produce deep-seated, bedrock involved slope failures? Recent storms suggest that within mobile regolith, individual

  8. Psoas Muscle Cross-sectional Area as a Measure of Whole-body Lean Muscle Mass in Maintenance Hemodialysis Patients.

    Science.gov (United States)

    Morrell, Glen R; Ikizler, Talat A; Chen, Xiaorui; Heilbrun, Marta E; Wei, Guo; Boucher, Robert; Beddhu, Srinivasan

    2016-07-01

    We investigate whether psoas or paraspinous muscle area measured on a single L4-L5 image is a useful measure of whole lean body mass (LBM) compared to dedicated midthigh magnetic resonance imaging (MRI). Observational study. Outpatient dialysis units and a research clinic. One hundred five adult participants on maintenance hemodialysis. No control group was used. Psoas muscle area, paraspinous muscle area, and midthigh muscle area (MTMA) were measured by magnetic resonance imaging. LBM was measured by dual-energy absorptiometry scan. In separate multivariable linear regression models, psoas, paraspinous, and MTMA were associated with increase in LBM. In separate multivariate logistic regression models, C statistics for diagnosis of sarcopenia (defined as <25th percentile of LBM) were 0.69 for paraspinous muscle area, 0.81 for psoas muscle area, and 0.89 for MTMA. With sarcopenia defined as <10th percentile of LBM, the corresponding C statistics were 0.71, 0.92, and 0.94. We conclude that psoas muscle area provides a good measure of whole-body muscle mass, better than paraspinous muscle area but slightly inferior to midthigh measurement. Hence, in body composition studies a single axial MR image at the L4-L5 level can be used to provide information on both fat and muscle and may eliminate the need for time-consuming measurement of muscle area in the thigh. Copyright © 2016 National Kidney Foundation, Inc. Published by Elsevier Inc. All rights reserved.

  9. Acetyl group availability influences phosphocreatine degradation even during intense muscle contraction.

    Science.gov (United States)

    Timmons, James A; Constantin-Teodosiu, Dumitru; Poucher, Simon M; Greenhaff, Paul L

    2004-12-15

    We previously established that activation of the pyruvate dehydrogenase complex (PDC) using dichloroacetate (DCA) reduced the reliance on substrate-level phosphorylation (SLP) at the onset of exercise, with normal and reduced blood flow. PDC activation also reduced fatigue development during contraction with reduced blood flow. Since these observations, several studies have re-evaluated our observations. One study demonstrated a performance benefit without a reduction in SLP, raising a question mark over PDC's role in the regulation of ATP regeneration and our interpretation of fatigue mechanisms. Using a model of muscle contraction similar to the conflicting study (i.e. tetanic rather than twitch stimulation), we re-examined this question. Using canine skeletal muscle, one group was infused with saline while the other was pretreated with 300 mg (kg body mass)(-1) DCA. Muscle biopsies were taken at rest, peak tension (1 min) and after 6 min of tetanic electrical stimulation (75 ms on-925 ms off per second) and blood flow was limited to 25% of normal values observed during contraction. DCA reduced phosphocreatine (PCr) degradation by 40% during the first minute of contraction, but did not prevent the almost complete depletion of PCr stores at 6 min, while muscle fatigue did not differ between the two groups. During intermittent tetanic stimulation PCr degradation was 75% greater than with our previous 3 Hz twitch contraction protocol, despite a similar rate of oxygen consumption at 6 min. Thus, in the present study enhanced acetyl group availability altered the time course of PCr utilization but did not prevent the decline towards depletion. Consistent with our earlier conclusions, DCA pretreatment reduces muscle fatigue only when SLP is attenuated. The present study and our met-analysis indicates that enhanced acetyl group availability results in a readily measurable reduction in SLP when the initial rate of PCr utilization is approximately 1 mmol (kg dry mass)(-1

  10. Strain in shock-loaded skeletal muscle and the time scale of muscular wobbling mass dynamics.

    Science.gov (United States)

    Christensen, Kasper B; Günther, Michael; Schmitt, Syn; Siebert, Tobias

    2017-10-16

    In terrestrial locomotion, muscles undergo damped oscillations in response to limb impacts with the ground. Muscles are also actuators that generate mechanical power to allow locomotion. The corresponding elementary contractile process is the work stroke of an actin-myosin cross-bridge, which may be forcibly detached by superposed oscillations. By experimentally emulating rat leg impacts, we found that full activity and non-fatigue must meet to possibly prevent forcible cross-bridge detachment. Because submaximal muscle force represents the ordinary locomotor condition, our results show that forcible, eccentric cross-bridge detachment is a common, physiological process even during isometric muscle contractions. We also calculated the stiffnesses of the whole muscle-tendon complex and the fibre material separately, as well as Young's modulus of the latter: 1.8 MPa and 0.75 MPa for fresh, fully active and passive fibres, respectively. Our inferred Young's modulus of the tendon-aponeurosis complex suggests that stiffness in series to the fibre material is determined by the elastic properties of the aponeurosis region, rather than the tendon material. Knowing these stiffnesses and the muscle mass, the complex' eigenfrequency for responses to impacts can be quantified, as well as the size-dependency of this time scale of muscular wobbling mass dynamics.

  11. Assessment of respiratory muscle strength in children according to the classification of body mass index

    Directory of Open Access Journals (Sweden)

    George Jung da Rosa

    2014-06-01

    Full Text Available OBJECTIVE: To assess and compare the respiratory muscle strength among eutrophic, overweight and obese school children, as well as to identify anthropometric and respiratory variables related to the results.METHODS: Cross-sectional survey with healthy schoolchildren aged 7-9 years old, divided into three groups: Normal weight, Overweight and Obese. The International Study of Asthma and Allergies in Childhood (ISAAC questionnaire was applied. The body mass index (BMI was evaluated, as well as the forced expiratory volume in one second (FEV1 with a portable digital device. The maximal inspiratory and expiratory pressures (MIP and MEP were measured by a digital manometer. Comparisons between the groups were made by Kruskal-Wallis test. Spearman's correlation coefficient was used to analyze the correlations among the variables.RESULTS: MIP of eutrophic school children was higher than MIP found in overweight (p=0.043 and obese (p=0.013 children. MIP was correlated with BMI percentile and weight classification (r=-0.214 and r=-0.256 and MEP was correlated with height (r=0.328. Both pressures showed strong correlation with each other in all analyses (r≥0.773, and less correlation with FEV1 (MIP - r=0.362 and MEP - r=0.494. FEV1 correlated with MEP in all groups (r: 0.429 - 0.569 and with MIP in Obese Group (r=0.565. Age was correlated with FEV1 (r=0.578, MIP (r=0.281 and MEP (r=0.328.CONCLUSIONS: Overweight and obese children showed lower MIP values, compared to eutrophic ones. The findings point to the influence of anthropometric variables on respiratory muscle strength in children.

  12. The influence of lower leg configurations on muscle force variability.

    Science.gov (United States)

    Ofori, Edward; Shim, Jaeho; Sosnoff, Jacob J

    2018-04-11

    The maintenance of steady contractions is required in many daily tasks. However, there is little understanding of how various lower limb configurations influence the ability to maintain force. The purpose of the current investigation was to examine the influence of joint angle on various lower-limb constant force contractions. Nineteen adults performed knee extension, knee flexion, and ankle plantarflexion isometric force contractions to 11 target forces, ranging from 2 to 95% maximal voluntary contraction (MVC) at 2 angles. Force variability was quantified with mean force, standard deviation, and the coefficient of variation of force output. Non-linearities in force output were quantified with approximate entropy. Curve fitting analyses were performed on each set of data from each individual across contractions to further examine whether joint angle interacts with global functions of lower-limb force variability. Joint angle had significant effects on the model parameters used to describe the force-variability function for each muscle contraction (p force output were more explained by force level in smaller angle conditions relative to the larger angle conditions (p force production. Biomechanical factors, such as joint angle, along with neurophysiological factors should be considered together in the discussion of the dynamics of constant force production. Copyright © 2018 Elsevier Ltd. All rights reserved.

  13. Mind-muscle connection training principle: influence of muscle strength and training experience during a pushing movement.

    Science.gov (United States)

    Calatayud, Joaquin; Vinstrup, Jonas; Jakobsen, Markus D; Sundstrup, Emil; Colado, Juan Carlos; Andersen, Lars L

    2017-07-01

    To investigate the effect of different attentional focus conditions on muscle activity during the push-up exercise and to assess the possible influence of muscle strength and training experience. Eighteen resistance-trained men performed 1RM bench press testing and were familiarized with the procedure during the first session. In the second session, three different conditions were randomly performed: regular push-up and push-up focusing on using the pectoralis major and triceps brachii muscles, respectively. Surface electromyography (EMG) was recorded and analyzed (EMG normalized to max; nEMG) for the triceps brachii and pectoralis major muscles. Participants had on average 8 (SD 6) years of training experience and 1RM of 1.25 (SD 0.28) kg per kg bodyweight. Focusing on using pectoralis major increased activity in this muscle by 9% nEMG (95% CI 5-13; Cohen's d 0.60) compared with the regular condition. Triceps activity was not significantly influenced by triceps focus although borderline significant, with a mean difference of 5% nEMG (95% CI 0-10; Cohen's d 0.30). However, years of training experience was positively associated with the ability to selectively activate the triceps (β = 0.41, P = 0.04), but not the pectoralis. Bench press 1RM was not significantly associated with the ability to selectively activate the muscles. Pectoralis activity can be increased when focusing on using this muscle during push-ups, whereas the ability to do this for the triceps is dependent on years of training experience. Maximal muscle strength does not appear to be a decisive factor for the ability to selectively activate these muscles.

  14. Role of Protein Carbonylation in Skeletal Muscle Mass Loss Associated with Chronic Conditions

    Directory of Open Access Journals (Sweden)

    Esther Barreiro

    2016-05-01

    Full Text Available Muscle dysfunction, characterized by a reductive remodeling of muscle fibers, is a common systemic manifestation in highly prevalent conditions such as chronic heart failure (CHF, chronic obstructive pulmonary disease (COPD, cancer cachexia, and critically ill patients. Skeletal muscle dysfunction and impaired muscle mass may predict morbidity and mortality in patients with chronic diseases, regardless of the underlying condition. High levels of oxidants may alter function and structure of key cellular molecules such as proteins, DNA, and lipids, leading to cellular injury and death. Protein oxidation including protein carbonylation was demonstrated to modify enzyme activity and DNA binding of transcription factors, while also rendering proteins more prone to proteolytic degradation. Given the relevance of protein oxidation in the pathophysiology of many chronic conditions and their comorbidities, the current review focuses on the analysis of different studies in which the biological and clinical significance of the modifications induced by reactive carbonyls on proteins have been explored so far in skeletal muscles of patients and animal models of chronic conditions such as COPD, disuse muscle atrophy, cancer cachexia, sepsis, and physiological aging. Future research will elucidate the specific impact and sites of reactive carbonyls on muscle protein content and function in human conditions.

  15. Anti-myostatin antibody increases muscle mass and strength and improves insulin sensitivity in old mice.

    Science.gov (United States)

    Camporez, João-Paulo G; Petersen, Max C; Abudukadier, Abulizi; Moreira, Gabriela V; Jurczak, Michael J; Friedman, Glenn; Haqq, Christopher M; Petersen, Kitt Falk; Shulman, Gerald I

    2016-02-23

    Sarcopenia, or skeletal muscle atrophy, is a debilitating comorbidity of many physiological and pathophysiological processes, including normal aging. There are no approved therapies for sarcopenia, but the antihypertrophic myokine myostatin is a potential therapeutic target. Here, we show that treatment of young and old mice with an anti-myostatin antibody (ATA 842) for 4 wk increased muscle mass and muscle strength in both groups. Furthermore, ATA 842 treatment also increased insulin-stimulated whole body glucose metabolism in old mice, which could be attributed to increased insulin-stimulated skeletal muscle glucose uptake as measured by a hyperinsulinemic-euglycemic clamp. Taken together, these studies provide support for pharmacological inhibition of myostatin as a potential therapeutic approach for age-related sarcopenia and metabolic disease.

  16. Leg blood flow is impaired during small muscle mass exercise in patients with COPD

    DEFF Research Database (Denmark)

    Iepsen, Ulrik Winning; Munch, Gregers Druedal Wibe; Rugbjerg, Mette

    2017-01-01

    to both endothelium-independent (SNP) and endothelium-dependent (ACh) stimulation. The results suggests that leg muscle blood flow is impaired during small muscle mass exercise in patients with COPD possibly due to impaired formation of prostacyclin and increased levels of endothelin-1.......Skeletal muscle blood flow is regulated to match the oxygen demand and dysregulation could contribute to exercise intolerance in patients with COPD. We measured leg hemodynamics and metabolites from vasoactive compounds in muscle interstitial fluid and plasma at rest, during one-legged knee...... the formation of interstitial prostacyclin (vasodilator) was only increased in the controls. There was no difference between groups in the nitrite/nitrate levels (vasodilator) in plasma or interstitial fluid during exercise. Moreover, patients and controls showed similar vasodilatory capacity in response...

  17. The influence of external compression on muscle blood flow during exercise

    International Nuclear Information System (INIS)

    Styf, J.

    1990-01-01

    Intramuscular pressures and muscle blood flow were measured in the anterior tibial muscle during dynamic concentric exercise in 14 subjects. Pressures were recorded by the microcapillary infusion method and muscle blood flow by the 133-Xenon clearance technique. Muscle blood flow during constant exercise decreased from 34.5 (SD = 10.3) to 10.6 (SD = 4.9) ml/100 g/min (P less than 0.001) when muscle relaxation pressure was increased from 13.5 (SD = 2.7) to 39.9 (SD = 9.0) mm Hg by external compression. Muscle relaxation pressure during exercise is the intramuscular pressure between contractions. External compression of the lower limb during exercise impedes muscle blood flow by increasing muscle relaxation pressure. The experimental model seems suitable to study the influence of external compression by knee braces on intramuscular pressure during exercise

  18. The Influence of Protein Supplementation on Muscle Hypertrophy

    Science.gov (United States)

    Fardi, A.; Welis, W.

    2018-04-01

    The problem of this study was the lack of knowledge about nutrition, so the use of protein supplements to support the occurrence of muscle hypertrophy is not optimal. The use of natural supplements is a substitute of the manufacturer's supplements. The purpose of this study was to determine the effect of natural protein supplementation to muscle hypertrophy.The method of the research was a quasi experiment. There are 26 subject and were divided two group. Instrument of this research is to use tape measure and skinfold to measure muscle rim and thickness of fat in arm and thigh muscle. Then to calculate the circumference of the arm and thigh muscles used the formula MTC - (3.14 x TSF). MTC is the arm muscle or thigh muscle and TSF is the thickness of the muscles of the arm or thigh muscles. Data analysis technique used was t test at 5% significant level. The result of the research showed that average score of arm muscle hypertrophy at pretest control group was 255.61 + 17.69 mm and posttest average score was 263.48.58 + 17.21 mm and average score of thigh muscle hypertrophy at pretest control group was 458.32 + 8.72 mm and posttest average score was 468.78 + 11.54 mm. Average score of arm muscle hypertrophy at pretest experiment group was 252.67 + 16.05 mm and posttest average score was 274.58 ± 16.89 mm and average score of thigh muscle hypertrophy at pretest experiment group was 459.49 ± 6.99 mm and posttest average score was 478.70 + 9.05 mm. It can be concluded that there was a significant effect of natural protein supplementation on muscle hypertrophy.

  19. Tissue Selective Androgen Receptor Modulators (SARMs) Increase Pelvic Floor Muscle Mass in Ovariectomized Mice.

    Science.gov (United States)

    Ponnusamy, Suriyan; Sullivan, Ryan D; Thiyagarajan, Thirumagal; Tillmann, Heather; Getzenberg, Robert H; Narayanan, Ramesh

    2017-03-01

    Stress urinary incontinence (SUI), a prevalent condition, is represented by an involuntary leakage of urine that results, at least in part, from weakened or damaged pelvic floor muscles and is triggered by physical stress. Current treatment options are limited with no oral therapies available. The pelvic floor is rich in androgen receptor and molecules with anabolic activity including selective androgen receptor modulators (SARMs) may serve as therapeutic options for individuals with SUI. In this study, two SARMs (GTx-024 and GTx-027) were evaluated in a post-menopausal animal model in order to determine their effect on pelvic floor muscles. Female C57BL/6 mice were ovariectomized and their pelvic muscles allowed to regress. The animals were then treated with vehicle or doses of GTx-024 or GTx-027. Animal total body weight, lean body mass, and pelvic floor muscle weights were measured along with the expression of genes associated with muscle catabolism. Treatment with the SARMs resulted in a restoration of the pelvic muscles to the sham-operated weight. Coordinately, the induction of genes associated with muscle catabolism was inhibited. Although a trend was observed towards an increase in total lean body mass in the SARM-treated groups, no significant differences were detected. Treatment of an ovariectomized mouse model with SARMs resulted in an increase in pelvic floor muscles, which may translate to an improvement of symptoms associated with SUI and serves as the basis for evaluating their clinical use. J. Cell. Biochem. 118: 640-646, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  20. Loss of mass and performance in skeletal muscle tissue: a continuum model

    Directory of Open Access Journals (Sweden)

    Giantesio Giulia

    2018-02-01

    Full Text Available We present a continuum hyperelastic model which describes the mechanical response of a skeletal muscle tissue when its strength and mass are reduced by aging. Such a reduction is typical of a geriatric syndrome called sarcopenia. The passive behavior of the material is described by a hyperelastic, polyconvex, transversely isotropic strain energy function, and the activation of the muscle is modeled by the so called active strain approach. The loss of ability of activating of an elder muscle is then obtained by lowering of some percentage the active part of the stress, while the loss of mass is modeled through a multiplicative decomposition of the deformation gradient. The obtained stress-strain relations are graphically represented and discussed in order to study some of the effects of sarcopenia.

  1. Premature loss of muscle mass and function in type 2 diabetes.

    Science.gov (United States)

    Guerrero, N; Bunout, D; Hirsch, S; Barrera, G; Leiva, L; Henríquez, S; De la Maza, M P

    2016-07-01

    Muscle mass and function are among the most relevant factors that contribute to an optimal quality of life, and are strong predictors of mortality in the elderly. Loss of lean tissues and deterioration of muscle function have been described as one of the many complications of type 2 diabetes mellitus (DM2), but most studies do not isolate age as an intervening factor. To study whether adult DM2 patients up to 60years of age have decreased muscle mass and function compared with healthy non-diabetic (ND) subjects of similar age. Appendicular fat-free mass (ApFFM) by dual X-ray absorptiometry (DEXA), handgrip strength (HS), quadriceps strength (QS), 12 min walking capacity (12MW) and the Timed Up and Go test (TUG) were measured in 100 DM2 patients and 39 ND controls. Muscle quality, or the ratio between lean mass and muscle strength of upper and lower limbs, and the functional limitations associated with pain and stiffness assessed according to the Western Ontario and McMaster Universities Arthrosis Index (WOMAC) were also recorded. Specific tests were performed to rule out microvascular diabetic complications (retinal and peripheral nerves), metabolic control, kidney function and vitamin D status and examine their association with ApFFM and function. ApFFM was significantly higher among DM2 female patients and lower among diabetic men. However opposite results were obtained when individual values were corrected for body mass index (BMI), specifically among women, who were more likely to be obese. As for muscle strength and global functionality tests, significantly better performances in TUG, 12MW, QS and HS were observed among ND subjects of both sexes. These differences prevailed even after excluding diabetic patients with microvascular complications as well as those with more than 10years of diabetes. Muscle quality was also significantly better among ND women. Higher scores of pain and stiffness in the WOMAC scale correlated with 12MW and TUG in both groups but

  2. Strength Exercise Improves Muscle Mass and Hepatic Insulin Sensitivity in Obese Youth

    NARCIS (Netherlands)

    Van Der Heijden, Gert-Jan; Wang, Zhiyue J.; Chu, Zili; Toffolo, Gianna; Manesso, Erica; Sauer, Pieter J. J.; Sunehag, Agneta L.

    VAN DER HEIJDEN, G.-J., Z. J. WANG, Z. CHU, G. TOFFOLO, E. MANESSO, P. J. J. SAUER, and A. L. SUNEHAG. Strength Exercise Improves Muscle Mass and Hepatic Insulin Sensitivity in Obese Youth. Med. Sci. Sports Exerc., Vol. 42, No. 11, pp. 1973-1980, 2010. Introduction: Data on the metabolic effects of

  3. Postoperative loss of skeletal muscle mass, complications and quality of life in patients undergoing cardiac surgery

    NARCIS (Netherlands)

    van Venrooij, Lenny M. W.; Verberne, Hein J.; de Vos, Rien; Borgmeijer-Hoelen, Mieke M. M. J.; van Leeuwen, Paul A. M.; de Mol, Bas A. J. M.

    2012-01-01

    Objective: The objective of this study was to describe postoperative undernutrition in terms of postoperative losses of appendicular skeletal muscle mass (ASMM) with respect to complications, quality of life, readmission, and 1-y mortality after cardiac surgery. Methods: Patients undergoing cardiac

  4. Strength Exercise Improves Muscle Mass and Hepatic Insulin Sensitivity in Obese Youth

    NARCIS (Netherlands)

    Van Der Heijden, Gert-Jan; Wang, Zhiyue J.; Chu, Zili; Toffolo, Gianna; Manesso, Erica; Sauer, Pieter J. J.; Sunehag, Agneta L.

    2010-01-01

    VAN DER HEIJDEN, G.-J., Z. J. WANG, Z. CHU, G. TOFFOLO, E. MANESSO, P. J. J. SAUER, and A. L. SUNEHAG. Strength Exercise Improves Muscle Mass and Hepatic Insulin Sensitivity in Obese Youth. Med. Sci. Sports Exerc., Vol. 42, No. 11, pp. 1973-1980, 2010. Introduction: Data on the metabolic effects of

  5. Low vitamin D and high parathyroid hormone levels as determinants of loss of muscle strength and muscle mass (sarcopenia) : the Longitudinal Aging Study Amsterdam

    NARCIS (Netherlands)

    Visser, Marjolein; Deeg, Dorly J H; Lips, Paul

    2003-01-01

    The age-related change in hormone concentrations has been hypothesized to play a role in the loss of muscle mass and muscle strength with aging, also called sarcopenia. The aim of this prospective study was to investigate whether low serum 25-hydroxyvitamin D (25-OHD) and high serum PTH

  6. Signalling pathways regulating muscle mass in ageing skeletal muscle. The role of the IGF1-Akt-mTOR-FoxO pathway

    NARCIS (Netherlands)

    Sandri, M.; Barberi, L.; Bijlsma, A.Y.; Blaauw, B.; Dyar, K.A.; Milan, G.; Mammucari, C.; Meskers, C.G.M.; Pallafacchina, G.; Paoli, A.; Pion, D.; Roceri, M.; Romanello, V.; Serrano, A.L.; Toniolo, L.; Larsson, L.; Maier, A.B.; Munoz-Canoves, P.; Musaro, A.; Pende, M.; Reggiani, C.; Rizzuto, R.; Schiaffino, S.

    2013-01-01

    During ageing skeletal muscles undergo a process of structural and functional remodelling that leads to sarcopenia, a syndrome characterized by loss of muscle mass and force and a major cause of physical frailty. To determine the causes of sarcopenia and identify potential targets for interventions

  7. The influence of experimentally induced pain on shoulder muscle activity

    DEFF Research Database (Denmark)

    Diederichsen, L.P.; Winther, A.; Dyhre-Poulsen, P.

    2009-01-01

    muscles. EMG was recorded before pain, during pain and after pain had subsided and pain intensity was continuously scored on a visual analog scale (VAS). During abduction, experimentally induced pain in the supraspinatus muscle caused a significant decrease in activity of the anterior deltoid, upper......-105A degrees) at a speed of approximately 120A degrees/s, controlled by a metronome. During abduction, electromyographic (EMG) activity was recorded by intramuscular wire electrodes inserted in two deeply located shoulder muscles and by surface-electrodes over six superficially located shoulder...... trapezius and the infraspinatus and an increase in activity of lower trapezius and latissimus dorsi muscles. Following subacromial injection a significantly increased muscle activity was seen in the lower trapezius, the serratus anterior and the latissimus dorsi muscles. In conclusion, this study shows...

  8. Age associated declines in muscle mass, strength, power, and physical performance: impact on fear of falling and quality of life

    Science.gov (United States)

    SUMMARY: This 3 year longitudinal study among older adults showed that declining muscle mass, strength, power, and physical performance are independent contributing factors to increased fear of falling, while declines of muscle mass and physical performance contribute to deterioration of quality of ...

  9. Pro-inflammatory capacity of classically activated monocytes relates positively to muscle mass and strength.

    Science.gov (United States)

    Beenakker, Karel G M; Westendorp, Rudi G J; de Craen, Anton J M; Slagboom, Pieternella E; van Heemst, Diana; Maier, Andrea B

    2013-08-01

    In mice, monocytes that exhibit a pro-inflammatory profile enter muscle tissue after muscle injury and are crucial for clearance of necrotic tissue and stimulation of muscle progenitor cell proliferation and differentiation. The aim of this study was to test if pro-inflammatory capacity of classically activated (M1) monocytes relates to muscle mass and strength in humans. This study included 191 male and 195 female subjects (mean age 64.2 years (SD 6.4) and 61.9 ± 6.4, respectively) of the Leiden Longevity Study. Pro-inflammatory capacity of M1 monocytes was assessed by ex vivo stimulation of whole blood with Toll-like receptor (TLR) 4 agonist lipopolysaccharide (LPS) and TLR-2/1 agonist tripalmitoyl-S-glycerylcysteine (Pam₃Cys-SK₄), both M1 phenotype activators. Cytokines that stimulate M1 monocyte response (IFN-γ and GM-CSF) as well as cytokines that are secreted by M1 monocytes (IL-6, TNF-α, IL-12, and IL-1β) were measured. Analyses were adjusted for age, height, and body fat mass. Upon stimulation with LPS, the cytokine production capacity of INF-γ, GM-CSF, and TNF-α was significantly positively associated with lean body mass, appendicular lean mass and handgrip strength in men, but not in women. Upon stimulation with Pam₃Cys-SK₄, IL-6; TNF-α; and Il-1β were significantly positively associated with lean body mass and appendicular lean in women, but not in men. Taken together, this study shows that higher pro-inflammatory capacity of M1 monocytes upon stimulation is associated with muscle characteristics and sex dependent. © 2013 John Wiley & Sons Ltd and the Anatomical Society.

  10. Relationship between Handgrip Strength and Muscle Mass in Female Survivors of Breast Cancer: A Mediation Analysis.

    Science.gov (United States)

    Benavides-Rodríguez, Lorena; García-Hermoso, Antonio; Rodrigues-Bezerra, Diogo; Izquierdo, Mikel; Correa-Bautista, Jorge Enrique; Ramírez-Vélez, Robinson

    2017-07-04

    This study explored the mediating factors of sarcopenia in a group of women survivors of breast cancer in Bogotá, Colombia. This was a descriptive cross-sectional study with 98 women survivors of breast cancer, who were registered with the SIMMON (Integrated Synergies to Improve Oncological Management in Colombia) Foundation. Body weight, height, and waist circumference (WC) were measured, and body mass index (BMI) was calculated. Body composition (percentage of fat and muscle mass) was evaluated via four-pole bioelectrical impedance analysis. Sarcopenia was defined as low muscle mass plus low grip strength or low gait speed (European Working Group on Sarcopenia in Older People (EWGSOP) criteria). A "causal" mediation analysis with the Baron & Kenny procedure (PROCESS ® macro, Columbus, OH, USA) was used to explore variables related to sarcopenia. Analyses were performed with the IBM SPSS 21 statistical package (SPSS Inc., Chicago, IL, USA). The significance level of the results obtained in the hypothesis contrast was p < 0.05. The mean age of the sample was 65.5 ± 5.9 years, with a BMI of 27.8 ± 4.7 kg/m². The prevalence of sarcopenia was 22.4%. Linear regression models suggest a partial mediation of anthropometric parameters (body mass, body mass index and waist circumference) in the association between handgrip strength and muscle mass. In conclusion, one in every five women survivors of breast cancer had sarcopenia. The findings seem to emphasize the importance of obesity prevention in women survivors of breast cancer, suggesting that high handgrip strength may not relate closely to greater muscle mass and therefore would not exclude the risk of sarcopenia.

  11. Influence of Cryotherapy on muscle strength: A Literaturae Review

    Directory of Open Access Journals (Sweden)

    Gilvaney Gomes Pereira

    2013-01-01

    Full Text Available The objective of this study was to verify the behavior of muscle strength before cryotherapy use through a literature review. To write this review it was performed the analysis of works with descriptive-analytical approach about the interference of cryotherapy in the muscle strength, and the total of the studies collected was 15. After analysis of collected studies of scientific sources it was verified that there were controversies in the researches found about the muscle strength increased or reduction. It is necessary to conduct new studies that will elucidate physiological effects of ice on the muscle strength.

  12. INFLUENCE OF CRYOTHERAPY ON MUSCLE STRENGTH: A LITERATURE REVIEW

    Directory of Open Access Journals (Sweden)

    Gilvaney Gomes Pereira

    2013-01-01

    Full Text Available The objective of this study was to verify the behavior of muscle strength before cryotherapy use through a literature review. To write this review it was performed the analysis of works with descriptive-analytical approach about the interference of cryotherapy in the muscle strength, and the total of the studies collected was 15. After analysis of collected studies of scientific sources it was verified that there were controversies in the researches found about the muscle strength increased or reduction. It is necessary to conduct new studies that will elucidate physiological effects of ice on the muscle strength.

  13. Experiments for obtaining field influence mass particles.

    CERN Document Server

    Yahalomi, E

    2010-01-01

    Analyzing time dilation experiments the existence of a universal field interacting with moving mass particles is obtained. It is found that mass particle changes its properties depend on its velocity relative to this universal scalar field and not on its velocity relative to the laboratory. High energy proton momentum, energy and mass were calculated obtaining new results. Experiments in high energy accelerators are suggested as additional proofs for the existence of this universal field. This universal field may explain some results of other high energy experiments.

  14. Health worries: analysis of mass media influence

    OpenAIRE

    Beléndez, Marina; Martín Llaguno, Marta; Suriá Martínez, Raquel; Hernández-Ruiz, Alejandra

    2004-01-01

    Póster presentado en 18th Annual Conference of the European Health Psychology Society, 21-24 June 2004, Helsinki, Finland. During the last years, mass media have centred on health and illness information more than ever before and stories about health risks fill up newspapers, magazines, TV programmes and internet sites. Recently, much of these informations are focused on emergent health risks, such as genetically modified food. In western countries, mass media appear as one of the main ...

  15. Effect of restriction vegan diet's on muscle mass, oxidative status, and myocytes differentiation: A pilot study.

    Science.gov (United States)

    Vanacore, Daniela; Messina, Giovanni; Lama, Stefania; Bitti, Giuseppe; Ambrosio, Pasqualina; Tenore, Giancarlo; Messina, Antonietta; Monda, Vincenzo; Zappavigna, Silvia; Boccellino, Mariarosaria; Novellino, Ettore; Monda, Marcellino; Stiuso, Paola

    2018-01-10

    This study was conceived to evaluate the effects of three different diets on body composition, metabolic parameters, and serum oxidative status. We enrolled three groups of healthy men (omnivores, vegetarians, and vegans) with similar age, weight and BMI, and we observed a significant decrease in muscle mass index and lean body mass in vegan compared to vegetarian and omnivore groups, and higher serum homocysteine levels in vegetarians and vegans compared to omnivores. We studied whether serum from omnivore, vegetarian, and vegan subjects affected oxidative stress, growth and differentiation of both cardiomyoblast cell line H9c2 and H-H9c2 (H9c2 treated with H 2 O 2 to induce oxidative damage). We demonstrated that vegan sera treatment of both H9c2 and H-H9c2 cells induced an increase of TBARS values and cell death and a decrease of free NO 2- compared to vegetarian and omnivorous sera. Afterwards, we investigated the protective effects of vegan, vegetarian, and omnivore sera on the morphological changes induced by H 2 O 2 in H9c2 cell line. We showed that the omnivorous sera had major antioxidant and differentiation properties compared to vegetarian and vegan sera. Finally, we evaluated the influence of the three different groups of sera on MAPKs pathway and our data suggested that ERK expression increased in H-H9c2 cells treated with vegetarian and vegan sera and could promote cell death. The results obtained in this study demonstrated that restrictive vegan diet could not prevent the onset of metabolic and cardiovascular diseases nor protect by oxidative damage. © 2018 Wiley Periodicals, Inc.

  16. Muscle mass, BMI, and mortality among adults in the United States: A population-based cohort study.

    Science.gov (United States)

    Abramowitz, Matthew K; Hall, Charles B; Amodu, Afolarin; Sharma, Deep; Androga, Lagu; Hawkins, Meredith

    2018-01-01

    The level of body-mass index (BMI) associated with the lowest risk of death remains unclear. Although differences in muscle mass limit the utility of BMI as a measure of adiposity, no study has directly examined the effect of muscle mass on the BMI-mortality relationship. Body composition was measured by dual-energy x-ray absorptiometry in 11,687 participants of the National Health and Nutrition Examination Survey 1999-2004. Low muscle mass was defined using sex-specific thresholds of the appendicular skeletal muscle mass index (ASMI). Proportional hazards models were created to model associations with all-cause mortality. At any level of BMI ≥22, participants with low muscle mass had higher body fat percentage (%TBF), an increased likelihood of diabetes, and higher adjusted mortality than other participants. Increases in %TBF manifested as 30-40% smaller changes in BMI than were observed in participants with preserved muscle mass. Excluding participants with low muscle mass or adjustment for ASMI attenuated the risk associated with low BMI, magnified the risk associated with high BMI, and shifted downward the level of BMI associated with the lowest risk of death. Higher ASMI was independently associated with lower mortality. Effects were similar in never-smokers and ever-smokers. Additional adjustment for waist circumference eliminated the risk associated with higher BMI. Results were unchanged after excluding unintentional weight loss, chronic illness, early mortality, and participants performing muscle-strengthening exercises or recommended levels of physical activity. Muscle mass mediates associations of BMI with adiposity and mortality and is inversely associated with the risk of death. After accounting for muscle mass, the BMI associated with the greatest survival shifts downward toward the normal range. These results provide a concrete explanation for the obesity paradox.

  17. The influence of flow redistribution on working rat muscle oxygenation.

    NARCIS (Netherlands)

    Hoofd, L.J.C.; Degens, H.

    2009-01-01

    We applied a theoretical model of muscle tissue O2 transport to investigate the effects of flow redistribution on rat soleus muscle oxygenation. The situation chosen was the anaerobic threshold where redistribution of flow is expected to have the largest impact. In the basic situation all

  18. Protein needs in athletes and dietary-nutrition guidelines to gain muscle mass

    Directory of Open Access Journals (Sweden)

    Aritz Urdampilleta

    2014-05-01

    Full Text Available One of the most important effects of strength training is muscular hypertrophy. Athletes should optimize their nutritional management in order to compensate their own genetic limitations. The aim of this review is to analyze the scientific evidence concerning protein intake as a tool to achieve muscle hypertrophy. Depending on the expenditure and energy intake of athlete, a daily protein ranging between 10-15% of total dietary intake is needed. However in sports diets, it is preferable to estimate the amount of protein needed per kilogram of body weight in each individual. In this regard athletes should ingest an amount between 1.2 g and 1.8 g of proteins/kg of body mass/day to maintain their lean mass. In order to increase muscle mass (0.5 kg/week, athletes should take between 1.6 g and 1.8 g of protein/kg/day with an increase of 400-500 kcal in their daily diet. These needs will depend on the sport, muscular catabolic status, the athlete’s lean mass and glycogen stores. Protein needs will increase if muscle and liver glycogen stores are empty. Excess of protein intake (more than 2 g/kg/day, with full glycogen stores, does not benefit the athlete and could cause an increase in circulating ketones and urea, thereby producing an early dehydration.

  19. Impact of fat mass distribution body shapes on muscles strength and the joints pain

    Directory of Open Access Journals (Sweden)

    Zerf Mohammed

    2016-01-01

    Full Text Available Our study focuses on fat mass distribution body shapes type as measured to determine their effect on skeletal muscle strengthening lumbar extensors (upper and lower limbs where our background confirms that every girl has a natural body type of rectangle, apple, pear, or hourglass. It is good for her to know which type of body shape she is, so she can learn what exercises to do, whereas similar studies suggest that it is much better to challenge weight problems with exercise and dietary measures before resorting to figure shaping. For this purpose, our study was carried out with a total of thirty students, females listed in the Institute of Physical Education and Sport, University of Mostaganem, aged between 20 and 23 years; their homogeneity was based on age, sex, and academic specialty, classified based on the body mass index (BMI into two groups (normal and overweight and based on their body shape′s type into three groups (9 pear shape, 10 rectangle shape, and 11 hourglass shape as a protocol experimental to examine the impact of fat mass distribution body shapes type on lumbar extensor strength. Based on our data analysis, we confirm that the pear and the rectangle shape affect the strength lumbar extensors due to body weight distribution which increases the risks relating to the skeletal muscles. Weight gain is a factor contributing to the weakness of skeletal muscles. However, the body shape explains the anomalies of the distribution of fat mass and BMI risk observed in our sample in the lower and upper part of the body recorded by the values of Killy test and endurance of trunk, the case of the pear and the rectangle shape back pain, which are consisting in excess of the body fat distributed in comparison with less percentage of muscle mass. Whereas this difference can affect the pelvic position.

  20. Ultrasonographic evaluation of the calf muscle mass and architecture in elderly patients with and without sarcopenia.

    Science.gov (United States)

    Kuyumcu, Mehmet Emin; Halil, Meltem; Kara, Özgür; Çuni, Bledjan; Çağlayan, Gökhan; Güven, Serdar; Yeşil, Yusuf; Arık, Güneş; Yavuz, Burcu Balam; Cankurtaran, Mustafa; Özçakar, Levent

    2016-01-01

    To sonographically assess the muscle mass and architecture of sarcopenic elderly subjects, and to explore the utility of ultrasound (US) measurements in predicting sarcopenia. One hundred elderly subjects were enrolled in this cross-sectional study. Mean age value of our study population was 73.08±6.18years. The diagnosis of sarcopenia was confirmed by measuring fat-free mass index (using bioelectrical impedance analysis) and handgrip strength. Calf circumference was measured and US evaluations comprised bilateral gastrocnemius muscle (MG) thickness, fascicle length and pennate angles; subcutaneous fat and dermis thicknesses in the calf. Bilateral muscle thickness and fascicle length values were significantly lower in patients with sarcopenia (both psarcopenia (all values>76.92%). Gastrocnemius muscle thickness and fascicle length values are lower in sarcopenic elderly and these two parameters can serve as alternative measurements for predicting/quantifying sarcopenia. Calf circumference measurements alone may not be appropriate for assessing sarcopenia. Instead, US imaging can conveniently be used to evaluate different compartments of the musculoskelal system in (sarcopenic) elderly. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  1. Platelet-Derived Growth Factor BB Influences Muscle Regeneration in Duchenne Muscle Dystrophy.

    Science.gov (United States)

    Piñol-Jurado, Patricia; Gallardo, Eduard; de Luna, Noemi; Suárez-Calvet, Xavier; Sánchez-Riera, Carles; Fernández-Simón, Esther; Gomis, Clara; Illa, Isabel; Díaz-Manera, Jordi

    2017-08-01

    Duchenne muscular dystrophy (DMD) is characterized by a progressive loss of muscle fibers, and their substitution by fibrotic and adipose tissue. Many factors contribute to this process, but the molecular pathways related to regeneration and degeneration of muscle are not completely known. Platelet-derived growth factor (PDGF)-BB belongs to a family of growth factors that regulate proliferation, migration, and differentiation of mesenchymal cells. The role of PDGF-BB in muscle regeneration in humans has not been studied. We analyzed the expression of PDGF-BB in muscle biopsy samples from controls and patients with DMD. We performed in vitro experiments to understand the effects of PDGF-BB on myoblasts involved in the pathophysiology of muscular dystrophies and confirmed our results in vivo by treating the mdx murine model of DMD with repeated i.m. injections of PDGF-BB. We observed that regenerating and necrotic muscle fibers in muscle biopsy samples from DMD patients expressed PDGF-BB. In vitro, PDGF-BB attracted myoblasts and activated their proliferation. Analysis of muscles from the animals treated with PDGF-BB showed an increased population of satellite cells and an increase in the number of regenerative fibers, with a reduction in inflammatory infiltrates, compared with those in vehicle-treated mice. Based on our results, PDGF-BB may play a protective role in muscular dystrophies by enhancing muscle regeneration through activation of satellite cell proliferation and migration. Copyright © 2017 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

  2. Proteome-wide muscle protein fractional synthesis rates predict muscle mass gain in response to a selective androgen receptor modulator in rats.

    Science.gov (United States)

    Shankaran, Mahalakshmi; Shearer, Todd W; Stimpson, Stephen A; Turner, Scott M; King, Chelsea; Wong, Po-Yin Anne; Shen, Ying; Turnbull, Philip S; Kramer, Fritz; Clifton, Lisa; Russell, Alan; Hellerstein, Marc K; Evans, William J

    2016-03-15

    Biomarkers of muscle protein synthesis rate could provide early data demonstrating anabolic efficacy for treating muscle-wasting conditions. Androgenic therapies have been shown to increase muscle mass primarily by increasing the rate of muscle protein synthesis. We hypothesized that the synthesis rate of large numbers of individual muscle proteins could serve as early response biomarkers and potentially treatment-specific signaling for predicting the effect of anabolic treatments on muscle mass. Utilizing selective androgen receptor modulator (SARM) treatment in the ovariectomized (OVX) rat, we applied an unbiased, dynamic proteomics approach to measure the fractional synthesis rates (FSR) of 167-201 individual skeletal muscle proteins in triceps, EDL, and soleus. OVX rats treated with a SARM molecule (GSK212A at 0.1, 0.3, or 1 mg/kg) for 10 or 28 days showed significant, dose-related increases in body weight, lean body mass, and individual triceps but not EDL or soleus weights. Thirty-four out of the 94 proteins measured from the triceps of all rats exhibited a significant, dose-related increase in FSR after 10 days of SARM treatment. For several cytoplasmic proteins, including carbonic anhydrase 3, creatine kinase M-type (CK-M), pyruvate kinase, and aldolase-A, a change in 10-day FSR was strongly correlated (r(2) = 0.90-0.99) to the 28-day change in lean body mass and triceps weight gains, suggesting a noninvasive measurement of SARM effects. In summary, FSR of multiple muscle proteins measured by dynamics of moderate- to high-abundance proteins provides early biomarkers of the anabolic response of skeletal muscle to SARM. Copyright © 2016 the American Physiological Society.

  3. Hormonal and lifestyle determinants of appendicular skeletal muscle mass in men: the MINOS study.

    Science.gov (United States)

    Szulc, Pawel; Duboeuf, François; Marchand, François; Delmas, Pierre D

    2004-08-01

    Aging-related sarcopenia is characterized by a loss of muscle mass and strength and increased fatigability. However, studies of its determinants in elderly men are scarce. We investigated risk factors for sarcopenia in a large cohort of men. We analyzed 845 men aged 45-85 y who belonged to the MINOS cohort. Lifestyle factors (physical activity, tobacco smoking, alcohol intake, caffeine intake) were evaluated by using a standardized questionnaire. Appendicular skeletal muscle mass (ASM) was estimated by using dual-energy X-ray absorptiometry. The relative appendicular skeletal muscle mass index (RASM) was calculated as ASM/body height(2.3). Apparent free testosterone concentration (AFTC) and free testosterone index (FTI) were calculated on the basis of concentrations of total testosterone and sex hormone-binding globulin. RASM decreased with age (r = -0.29, P values for AFTC, FTI, or 25-hydroxycholecalciferol [25(OH)D] were >2 SDs below the mean for young men had significantly lower RASM than did men with higher values. Men with sarcopenia, defined as the lowest quartile of RASM in the studied cohort (normal RASM, weighed significantly less, smoked more, and spent significantly less time on leisure-time activities. Sarcopenic men also had lower values for testosterone, AFTC, FTI, and 25(OH)D. In elderly men, low physical activity, tobacco smoking, thinness, low testosterone (AFTC and FTI), and decreased 25(OH)D concentrations are risk factors for sarcopenia.

  4. Depression Is Associated With Muscle Mass And Strength In Patients With End Stage Renal Disease

    Directory of Open Access Journals (Sweden)

    Young Rim Song

    2012-06-01

    Full Text Available Depression is the most common psychiatric complication in patients with end-stage renal disease (ESRD. Sarcopenia, defined as loss of muscle mass and strength, is expected to be associated with depression, because both are closely linked to physical inactivity and functional impairment. We investigated the association of sarcopenia with depression in patients with ESRD. A total of 115 patients undergoing hemodialysis (HD were included in this study. Muscle mass was assessed by lean tissue index (LTI using portable whole body bioimpedance spectroscopy, and muscle strength was measured with handgrip strength (HGS. Depression was defined as Beck Depression Inventory-II (BDI-II score ≥16. About 60% of prevalent HD patients had depression. Compared to subjects without depression, depressed patients had a higher prevalence of sarcopenia (45.5 vs. 8.2%, p<0.001 and significantly increased serum IL-6 and hs-CRP level. However, (prealbumin and body mass index (BMI failed to correlate with BDI-II. HGS and LTI had a consistent negative effect on BDI-II even after adjusting other parameters including inflammation. In multivariate analysis, lower , increased IL-6 and β2-microglobulin,and sarcopenia were significant predictors for depression; sarcopenia was most powerful [odds ratio 9.01, 95% CI 3.60-12.22, p=0.001]. In conclusion, the prevalence of sarcopenia and depression was considerably high and and the presence of sarcopenia was an important predictor for depression.

  5. Retardation of muscle growth in castrated male mice: further ...

    African Journals Online (AJOL)

    Retardation of muscle growth in castrated male mice was studied as an evidence for the influence of hormones on the development of muscle mass. Male albino mice were castrated at 28days of age by open castration method. The weights and the muscle mass indices (mg muscle weight per gram body weight) of the ...

  6. Age- and gender-dependent values of skeletal muscle mass in healthy children and adolescents

    OpenAIRE

    Webber, Colin E.; Barr, Ronald D.

    2011-01-01

    Background Skeletal muscle mass (SMM) can be extracted from whole-body scans obtained by X-ray-based dual-photon absorptiometry (DXA). There is a need to establish expected age-dependent values for children and adolescents. Methods Appendicular lean tissue mass (ALM) was extracted from whole-body DXA scans in 140 healthy children and adolescents (68 females and 72 males). Whole-body SMM was calculated from ALM using equations developed by Kim et al. (Am J Clin Nutr 84:1014–1020, 2006). Age-de...

  7. The influence of muscle physiology and advanced technology on sports performance.

    Science.gov (United States)

    Neptune, Richard R; McGowan, Craig P; Fiandt, John M

    2009-01-01

    Muscle mechanical output such as force and power are governed by highly nonlinear intrinsic muscle properties associated with different muscle fiber types and are influenced by training and age. Many of the interactions between these properties pose trade-offs such that an individual's anthropometrics and muscle morphology may allow an athlete to excel in one sport but not in others. Advanced modeling and simulation techniques are powerful tools to gain insight into performance limits, optimal equipment designs, and mechanisms that may lead to injury. Recent technological innovations have produced faster running tracks, bicycles, speed skates, and swimming pools. This review discusses the influence of intrinsic muscle properties in sports and how advanced technology can be used to extend the limits of human performance.

  8. Measurement of Muscle Protein Fractional Synthetic Rate by Capillary Gas Chromatography/Combustion Isotope Ratio Mass Spectrometry

    OpenAIRE

    Yarasheski, Kevin E.; Smith, Kenneth; Rennie, Michael J.; Bier, Dennis M.

    1992-01-01

    The measurement of skeletal muscle protein fractional synthetic rate using an infusion of (1-13C)leucine and measuring the isotopic abundance of the tracer in skeletal muscle protein by preparative gas chromatography (GC)/ninhydrin isotope ratio mass spectrometry (IRMS) is laborious and subject to errors owing to contamination by 12C. The purpose of this study was to compare muscle (13C)leucine enrichment measured with the conventional preparative GC/ninhydrin IRMS approach to a new, continuo...

  9. Time-Course of Muscle Mass Loss, Damage, and Proteolysis in Gastrocnemius following Unloading and Reloading: Implications in Chronic Diseases

    Science.gov (United States)

    Chacon-Cabrera, Alba; Lund-Palau, Helena; Gea, Joaquim; Barreiro, Esther

    2016-01-01

    Background Disuse muscle atrophy is a major comorbidity in patients with chronic diseases including cancer. We sought to explore the kinetics of molecular mechanisms shown to be involved in muscle mass loss throughout time in a mouse model of disuse muscle atrophy and recovery following immobilization. Methods Body and muscle weights, grip strength, muscle phenotype (fiber type composition and morphometry and muscle structural alterations), proteolysis, contractile proteins, systemic troponin I, and mitochondrial content were assessed in gastrocnemius of mice exposed to periods (1, 2, 3, 7, 15 and 30 days) of non-invasive hindlimb immobilization (plastic splint, I cohorts) and in those exposed to reloading for different time-points (1, 3, 7, 15, and 30 days, R cohorts) following a seven-day period of immobilization. Groups of control animals were also used. Results Compared to non-exposed controls, muscle weight, limb strength, slow- and fast-twitch cross-sectional areas, mtDNA/nDNA, and myosin content were decreased in mice of I cohorts, whereas tyrosine release, ubiquitin-proteasome activity, muscle injury and systemic troponin I levels were increased. Gastrocnemius reloading following splint removal improved muscle mass loss, strength, fiber atrophy, injury, myosin content, and mtDNA/nDNA, while reducing ubiquitin-proteasome activity and proteolysis. Conclusions A consistent program of molecular and cellular events leading to reduced gastrocnemius muscle mass and mitochondrial content and reduced strength, enhanced proteolysis, and injury, was seen in this non-invasive mouse model of disuse muscle atrophy. Unloading of the muscle following removal of the splint significantly improved the alterations seen during unloading, characterized by a specific kinetic profile of molecular events involved in muscle regeneration. These findings have implications in patients with chronic diseases including cancer in whom physical activity may be severely compromised. PMID

  10. Muscle mass decline, arterial stiffness, white matter hyperintensity, and cognitive impairment: Japan Shimanami Health Promoting Program study.

    Science.gov (United States)

    Kohara, Katsuhiko; Okada, Yoko; Ochi, Masayuki; Ohara, Maya; Nagai, Tokihisa; Tabara, Yasuharu; Igase, Michiya

    2017-08-01

    There is a close association between frailty and cognitive impairment. However, the underlying contribution of sarcopenia to the development of cognitive impairment is unclear. We investigated the possible association between muscle mass decline and cognitive impairment in a cross-sectional study of 1518 subjects aged 55 years or above. We also evaluated arterial stiffness and white matter hyperintensities (WMHs) as possible underlying mechanisms for this association. Two sarcopenic indices were measured: thigh muscle cross-sectional area (CSA; calculated by computed tomography) and skeletal muscle mass (bioelectric impedance). Muscle mass decline was defined as either the bottom 10% or 20% of participants for each sex. Cognitive function was assessed using the Touch Panel-type Dementia Assessment Scale, and brachial-ankle pulse wave velocity was measured as an index of arterial stiffness. Both sarcopenic indices were modestly but significantly associated with brachial-ankle pulse wave velocity in male and female subjects. The presence of WMHs was significantly associated with low thigh muscle CSA in men and with low skeletal muscle mass in women. The Touch Panel-type Dementia Assessment Scale score was modestly but significantly and positively associated with thigh muscle CSA in men and skeletal muscle mass in women. Muscle mass decline in the bottom 10% of participants on both sarcopenic indices was significantly and independently related to cognitive impairment in women. Lower sarcopenic indices are significantly related to lower cognitive scores. Arterial stiffness and WMHs could account, at least in part, for this association. © 2017 The Authors. Journal of Cachexia, Sarcopenia and Muscle published by John Wiley & Sons Ltd on behalf of the Society on Sarcopenia, Cachexia and Wasting Disorders.

  11. Estimation of thigh muscle mass with magnetic resonance imaging in older adults and people with chronic obstructive pulmonary disease.

    Science.gov (United States)

    Mathur, Sunita; Takai, Karen Pr; Macintyre, Donna L; Reid, Darlene

    2008-02-01

    Quantifying muscle mass is an essential part of physical therapy assessment, particularly in older adults and in people with chronic conditions associated with muscle atrophy. The purposes of this study were to examine the relationship between muscle cross-sectional area (CSA) and volume by use of magnetic resonance imaging (MRI) and to compare anthropometric estimations of midthigh CSA with measurements obtained from MRI. Twenty older adults who were healthy and 20 people with chronic obstructive pulmonary disease (COPD), matched for age, sex, and body mass index, underwent MRI to obtain measurements of thigh muscle CSA and volume. Anthropometric measurements (skinfold thickness and thigh circumference) were used to estimate midthigh CSA. Muscle volumes were significantly lower in the people with COPD than in the older adults who were healthy. Moderate to high correlations were found between midthigh CSA and volume in both groups (r=.61-.94). Anthropometric measurements tended to overestimate midthigh CSA in both the people with COPD (estimated CSA=64.9+/-17.8; actual CSA=48.3+/-10.2 cm(2)) and the older adults who were healthy (estimated quadriceps femoris muscle CSA=65.0+/-14.0; actual CSA=56.8+/-13.5 cm(2)). Furthermore, the estimated quadriceps femoris muscle CSAs were not sensitive enough to detect a difference in muscle size between people with COPD and controls. Thigh circumference alone was not different between groups and showed only low to moderate correlations with muscle volume (r=.19-.47). Muscle CSA measured from a single slice provides a good indication of volume, but the most representative slice should be chosen on the basis of the muscle group of interest. Thigh circumference is not correlated with muscle volume and, therefore, should not be used as an indicator of muscle size. The development of population-specific reference equations for estimating muscle CSA from anthropometric measurements is warranted.

  12. Supplementing Breakfast with a Vitamin D and Leucine-Enriched Whey Protein Medical Nutrition Drink Enhances Postprandial Muscle Protein Synthesis and Muscle Mass in Healthy Older Men.

    Science.gov (United States)

    Chanet, Audrey; Verlaan, Sjors; Salles, Jérôme; Giraudet, Christophe; Patrac, Véronique; Pidou, Véronique; Pouyet, Corinne; Hafnaoui, Nordine; Blot, Adeline; Cano, Noël; Farigon, Nicolas; Bongers, Anke; Jourdan, Marion; Luiking, Yvette; Walrand, Stéphane; Boirie, Yves

    2017-12-01

    Background: A promising strategy to help older adults preserve or build muscle mass is to optimize muscle anabolism through providing an adequate amount of high-quality protein at each meal. Objective: This "proof of principle" study investigated the acute effect of supplementing breakfast with a vitamin D and leucine-enriched whey protein medical nutrition drink on postprandial muscle protein synthesis and longer-term effect on muscle mass in healthy older adults. Methods: A randomized, placebo-controlled, double-blind study was conducted in 24 healthy older men [mean ± SD: age 71 ± 4 y; body mass index (in kg/m 2 ) 24.7 ± 2.8] between September 2012 and October 2013 at the Unit of Human Nutrition, University of Auvergne, Clermont-Ferrand, France. Participants received a medical nutrition drink [test group; 21 g leucine-enriched whey protein, 9 g carbohydrates, 3 g fat, 800 IU cholecalciferol (vitamin D 3 ), and 628 kJ] or a noncaloric placebo (control group) before breakfast for 6 wk. Mixed muscle protein fractional synthesis rate (FSR) was measured at week 0 in the basal and postprandial state, after study product intake with a standardized breakfast with the use of l-[ 2 H 5 ]-phenylalanine tracer methodology. The longer-term effect of the medical nutrition drink was evaluated by measurement of appendicular lean mass, representing skeletal muscle mass at weeks 0 and 6, by dual-energy X-ray absorptiometry. Results: Postprandial FSR (0-240 min) was higher in the test group than in the control group [estimate of difference (ED): 0.022%/h; 95% CI: 0.010%/h, 0.035%/h; ANCOVA, P = 0.001]. The test group gained more appendicular lean mass than the control group after 6 wk (ED: 0.37 kg; 95% CI: 0.03, 0.72 kg; ANCOVA, P = 0.035), predominantly as leg lean mass (ED: 0.30 kg; 95% CI: 0.03, 0.57 kg; ANCOVA, P = 0.034). Conclusions: Supplementing breakfast with a vitamin D and leucine-enriched whey protein medical nutrition drink stimulated postprandial muscle protein

  13. Skeletal muscle mass and quality as risk factors for postoperative outcome after open colon resection for cancer

    NARCIS (Netherlands)

    Boer, B. C.; de Graaff, F.; Brusse-Keizer, M.; Bouman, D. E.; Slump, C. H.; Slee-Valentijn, M.; Klaase, J. M.

    The prevalence of colorectal cancer in the elderly is increasing and, therefore, surgical interventions with a risk of potential complications are more frequently performed. This study investigated the role of low skeletal muscle mass (sarcopenia), muscle quality, and the sarcopenic obesity as

  14. Loss of Muscle Mass During Chemotherapy Is Predictive for Poor Survival of Patients With Metastatic Colorectal Cancer

    NARCIS (Netherlands)

    Blauwhoff-Buskermolen, Susanne; Versteeg, Kathelijn S.; de van der Schueren, Marian A. E.; den Braver, Nicole R.; Berkhof, Johannes; Langius, Jacqueline A. E.; Verheul, Henk M. W.

    2016-01-01

    Low muscle mass is present in approximately 40% of patients with metastatic colorectal cancer (mCRC) and may be associated with poor outcome. We studied change in skeletal muscle during palliative chemotherapy in patients with mCRC and its association with treatment modifications and overall

  15. The influence of fat infiltration of back extensor muscles on osteoporotic vertebral fractures.

    Science.gov (United States)

    So, Kwang-Young; Kim, Dae-Hee; Choi, Dong-Hyuk; Kim, Choong-Young; Kim, Jeong-Seok; Choi, Yong-Soo

    2013-12-01

    Retrospective study. To investigate the influence of fat infiltration at low back extensor muscles on osteoporotic vertebral fracture. In persons with stronger back muscles, the risk of osteoporotic vertebral fractures will likely be lower than in those persons with weaker back muscles. However, the degree of influence of fat infiltration of the back extensor muscle on osteoporotic vertebral fracture remains controversial. Two hundred and thirty-seven patients who had undergone lumbar spine magnetic resonance imaging and bone mineral density (BMD) were enrolled in this study. The amount of low back extensor muscle was determined using the pseudocoloring technique on an axial view of the L3 level. The patients were divided into two groups: osteoporotic vertebral fracture group (group A) and non-fracture group (group B). The amount of low back extensor muscle is compared with BMD, degenerative change of disc, osteophyte grade of facet joint and promontory angle to reveal the association between these factors. A negative correlation is found between age and the amount of low back extensor muscle (p=0.001). The amount of low back extensor muscle in group A and group B was 60.3%±14.5% and 64.2%±9.3% respectively, thus showing a significantly smaller amount of low back extensor muscle in the osteoporotic vertebral fracture group (p=0.015). Fat infiltration of low back extensor muscle was increased in osteoporotic vertebral fracture patients. Therefore, fat infiltration of low back extensor muscle in an elderly person may be a risk factor of osteoporotic vertebral fracture.

  16. The effects of dietary protein intake on appendicular lean mass and muscle function in elderly men

    DEFF Research Database (Denmark)

    Mitchell, Cameron J; Milan, Amber M; Mitchell, Sarah M

    2017-01-01

    Background: The Recommended Daily Allowance (RDA) for protein intake in the adult population is widely promoted as 0.8 g · kg-1 · d-1 Aging may increase protein requirements, particularly to maintain muscle mass.Objective: We investigated whether controlled protein consumption at the current RDA...... or twice the RDA (2RDA) affects skeletal muscle mass and physical function in elderly men.Design: In this parallel-group randomized trial, 29 men aged >70 y [mean ± SD body mass index (in kg/m2): 28.3 ± 4.2] were provided with a complete diet containing either 0.8 (RDA) or 1.6 (2RDA) g protein · kg-1 · d-1...... energy balance (mean ± SD RDA: 209 ± 213 kcal/d; 2RDA 145 ± 214 kcal/d; P= 0.427 for difference between the groups). In comparison with RDA, whole-body lean mass increased in 2RDA (P = 0.001; 1.49 ± 1.30 kg, P

  17. Female hormones: do they influence muscle and tendon protein metabolism?

    DEFF Research Database (Denmark)

    Hansen, Mette

    2018-01-01

    (or lack of female hormones) on skeletal muscle protein turnover at rest and in response to exercise. This review is primarily based on data from human trials. Many elderly post-menopausal women experience physical disabilities and loss of independence related to sarcopenia, which reduces life quality...

  18. Influence of synchronous and sequential stimulation on muscle fatigue

    NARCIS (Netherlands)

    Thomsen, M.; Thomsen, M.; Veltink, Petrus H.

    1997-01-01

    In acute experiments the sciatic nerve of the rat is electrically stimulated to induce fatigue in the medial Gastrocnemius muscle. Fatigue tests are carried out using intermittent stimulation of different compartments (sequential) or a single compartment (synchronous) of the sciatic nerve. The

  19. Texture-modified diets are associated with decreased muscle mass in older adults admitted to a rehabilitation ward.

    Science.gov (United States)

    Shimizu, Akio; Maeda, Keisuke; Tanaka, Kei; Ogawa, Mei; Kayashita, Jun

    2018-05-01

    Texture-modified diets (TMD) have significantly lower energy and protein content than normal diets. Therefore, TMD can cause malnutrition and loss of muscle mass. However, few studies have reported the relationship between TMD and decreased skeletal muscle mass. The aim of the present study was to clarify the association between TMD and decreased skeletal muscle mass. We reviewed data of 188 older adult patients who were admitted to a rehabilitation hospital. TMD were defined based on the Japanese Dysphagia Diet Criteria 2013 proposed by the Japanese Society of Dysphagia Rehabilitation. The Mini Nutritional Assessment-Short Form was used to assess nutritional status; dual-energy X-ray absorptiometry was used to measure the skeletal muscle mass index, and the cut-off values for decreased skeletal muscle mass index were based on the Asian Working Group for Sarcopenia; the Functional Independence Measure was used to evaluate activities of daily living. The patients' mean age was 80.6 ± 7.5 years, and 62% were women. A total of 22 patients (11.7%) consumed TMD. A total of 104 patients (55.3%) had decreased skeletal muscle mass, and approximately 90% of them consumed TMD. Decreased skeletal muscle mass index (odds ratio 7.199, 95% confidence interval 1.489-34.805, P ≤ 0.01) and Functional Independence Measure scores (odds ratio 0.972, 95% confidence interval 0.952-0.992, P ≤ 0.01) were independently related to TMD in the multivariate analysis. The TMD group was associated with decreased skeletal muscle mass. Future, prospective studies are necessary to investigate causality. Geriatr Gerontol Int 2018; 18: 698-704. © 2017 Japan Geriatrics Society.

  20. A mouse anti-myostatin antibody increases muscle mass and improves muscle strength and contractility in the mdx mouse model of Duchenne muscular dystrophy and its humanized equivalent, domagrozumab (PF-06252616), increases muscle volume in cynomolgus monkeys.

    Science.gov (United States)

    St Andre, Michael; Johnson, Mark; Bansal, Prashant N; Wellen, Jeremy; Robertson, Andrew; Opsahl, Alan; Burch, Peter M; Bialek, Peter; Morris, Carl; Owens, Jane

    2017-11-09

    The treatments currently approved for Duchenne muscular dystrophy (DMD), a progressive skeletal muscle wasting disease, address the needs of only a small proportion of patients resulting in an urgent need for therapies that benefit all patients regardless of the underlying mutation. Myostatin is a member of the transforming growth factor-β (TGF-β) family of ligands and is a negative regulator of skeletal muscle mass. Loss of myostatin has been shown to increase muscle mass and improve muscle function in both normal and dystrophic mice. Therefore, myostatin blockade via a specific antibody could ameliorate the muscle weakness in DMD patients by increasing skeletal muscle mass and function, thereby reducing patients' functional decline. A murine anti-myostatin antibody, mRK35, and its humanized analog, domagrozumab, were developed and their ability to inhibit several TGB-β ligands was measured using a cell-based Smad-activity reporter system. Normal and mdx mice were treated with mRK35 to examine the antibody's effect on body weight, lean mass, muscle weights, grip strength, ex vivo force production, and fiber size. The humanized analog (domagrozumab) was tested in non-human primates (NHPs) for changes in skeletal muscle mass and volume as well as target engagement via modulation of circulating myostatin. Both the murine and human antibodies are specific and potent inhibitors of myostatin and GDF11. mRK35 is able to increase body weight, lean mass, and muscle weights in normal mice. In mdx mice, mRK35 significantly increased body weight, muscle weights, grip strength, and ex vivo force production in the extensor digitorum longus (EDL) muscle. Further, tibialis anterior (TA) fiber size was significantly increased. NHPs treated with domagrozumab demonstrated a dose-dependent increase in lean mass and muscle volume and exhibited increased circulating levels of myostatin demonstrating target engagement. We demonstrated that the potent anti-myostatin antibody mRK35 and

  1. The Mass Media Influence on the Impact of Health Policy

    Directory of Open Access Journals (Sweden)

    Cătălin BABA

    2007-02-01

    Full Text Available The theme of this study is a distinct examination of the issues regarding health policy, social representations and mass media. The analysis of the mass media influence on the impact of health policy leads to a portrayal of the related programs and the way they are received by citizens through mass media. Owing to the mass media quality to be an indicator of democracy it is very important to study its role in setting people daily agenda considering how it is able to maintain and create trends merely through recurrent messages. The issues frequently conveyed by media industry influences citizens’ interest with regard to community, producing effects on public policy. We must bear in mind that the more persistent in media they are, the more relevant for community this issues will be. The authors of the study put forward a method through which diverse programmes can be analysed. A comparative analysis of mass media and citizens’ social representations and its findings provide information about the influence between them. According to agenda setting theory and many international studies on health policy the authors conclude that mass media institution highly influence the impact of the health policy in health. Moreover, it is important to mention that the impact refers to all the stages of a policy-making: beginning with the problem identification and ending with the evaluation of the implementation process.

  2. Lack of skeletal muscle IL-6 influences hepatic glucose metabolism in mice during prolonged exercise

    DEFF Research Database (Denmark)

    Bertholdt, Lærke; Gudiksen, Anders; Schwartz, Camilla Lindgren

    2017-01-01

    The liver is essential in maintaining and regulating glucose homeostasis during prolonged exercise. IL-6 has been shown to be secreted from skeletal muscle during exercise and has been suggested to signal to the liver. Therefore, the aim of this study was to investigate the role of skeletal muscle...... IL-6 on hepatic glucose regulation and substrate choice during prolonged exercise. Skeletal muscle-specific IL-6 knockout (IL-6 MKO) mice (age, 12-14 wk) and littermate lox/lox (Control) mice were either rested (Rest) or completed a single bout of exercise for 10, 60, or 120 min, and the liver....... Furthermore, IL-6 MKO mice had higher hepatic pyruvate dehydrogenase (PDH)Ser232 and PDHSer300 phosphorylation than control mice at rest. In conclusion, hepatic gluconeogenic capacity in mice is increased during prolonged exercise independent of muscle IL-6. Furthermore, Skeletal muscle IL-6 influences...

  3. Lean muscle mass in classic or ovulatory PCOS: association with central obesity and insulin resistance.

    Science.gov (United States)

    Mario, F M; do Amarante, F; Toscani, M K; Spritzer, P M

    2012-10-01

    This age-matched case-control study assessed total and segmental lean muscle mass in classic or ovulatory polycystic ovary syndrome (PCOS) patients and investigated whether lean mass is associated with hormone and metabolic features. Participants underwent anthropometric and clinical evaluation. Habitual physical activity was assessed with a digital pedometer, and body composition by dual-energy X-ray absorptiometry. Laboratory measurements included total cholesterol, cholesterol fractions, triglycerides, glucose, total serum testosterone, serum insulin, estradiol, luteinizing hormone, and SHBG. Energy intake was calculated using a food frequency questionnaire. Classic PCOS patients had higher body mass index (BMI), waist circumference, testosterone and lipid accumulation product values than ovulatory PCOS and controls. Energy consumption, homeostasis model assessment index, SHBG, free androgen index and triglycerides, total and trunk lean mass were higher only in classic PCOS women vs. controls. Arm, leg, trunk, total or limb lean masses were not correlated with hormone levels in any of the groups. However, in PCOS women lipid accumulation product was positively correlated with total (r=0.56, p=0.001), trunk (r=0.59, p=0.001), arm (r=0.54, p=0.001), leg (r=0.44, p=0.03) and limb (r=0.48, p=0.001) lean masses. BMI was positively correlated with all lean mass segments and independently associated with total lean mass. Lipid accumulation product and BMI were independently associated with trunk lean mass variation. The increase in lean mass in classic PCOS appears to be associated with insulin resistance and central obesity rather than with energy intake, physical activity or androgens. © J. A. Barth Verlag in Georg Thieme Verlag KG Stuttgart · New York.

  4. Initial Presentation of Renal Cell Carcinoma as a Metastatic Mass within the Masseter Muscle: A Case Report and Literature Review

    Energy Technology Data Exchange (ETDEWEB)

    Bae, Kyung Eun; Lee, Han Bee; Cho, Woo Ho; Kim, Jae Hyung; Lee, Ji Hae; Kang, Min Jin [Dept. of Radiology, Sanggye Paik Hospital, Inje University College of Medicine, Seoul (Korea, Republic of); Kim, Hyun Jung [Dept. of Pathology, Sanggye Paik Hospital, Inje University College of Medicine, Seoul (Korea, Republic of)

    2012-02-15

    Renal cell carcinoma (RCC) is often concomitant with distant metastasis, and these metastases are the first sign of an otherwise occult primary. Whereas metastasis of RCC to the head and neck has been reported, metastasis to the masseter muscle, which is composed of skeletal muscle, is quite rare. We now report the case of a 66-year-old man who had a past history of pulmonary tuberculosis, with RCC metastasis of a well-defined intensely enhancing hypervascular mass in the masseter muscle as the initial presentation. We present the imaging findings of this case and a literature review about radiologic differential diagnosis of intramasseteric masses.

  5. Type VI collagen turnover-related peptides—novel serological biomarkers of muscle mass and anabolic response to loading in young men

    DEFF Research Database (Denmark)

    Nedergaard, Anders; Sun, Shu; Karsdal, Morten A

    2013-01-01

    Immobilization-induced loss of muscle mass is a complex phenomenon with several parallels to sarcopenic and cachectic muscle loss. Muscle is a large organ with a protein turnover that is orders of magnitude larger than most other tissues. Thus, we hypothesize that muscle loss and regain is reflec...

  6. The role of fat mass and skeletal muscle mass in knee osteoarthritis is different for men and women: the NEO study

    NARCIS (Netherlands)

    Visser, A.W. de; Mutsert, R. de; Loef, M.; Cessie, S. le; Heijer, M. den; Bloem, J.L.; Reijnierse, M.; Rosendaal, F.R.; Kloppenburg, M.; Assendelft, W.J.J.; Smit, J.W.A.; et al.,

    2014-01-01

    OBJECTIVE: To investigate if the amount of fat mass (FM) or skeletal muscle mass (SMM) is more strongly associated with knee osteoarthritis (OA), in both men and women. METHODS: The Netherlands Epidemiology of Obesity (NEO) study is a population-based cohort aged 45-65 years, including 5313

  7. Influence of wheel size on muscle activity and tri-axial accelerations during cross-country mountain biking.

    Science.gov (United States)

    Hurst, Howard Thomas; Sinclair, Jonathan; Atkins, Stephen; Rylands, Lee; Metcalfe, John

    2017-07-01

    This study aimed to investigate the influence of different mountain bike wheel diameters on muscle activity and whether larger diameter wheels attenuate muscle vibrations during cross-country riding. Nine male competitive mountain bikers (age 34.7 ± 10.7 years; stature 177.7 ± 5.6 cm; body mass 73.2 ± 8.6 kg) participated in the study. Riders performed one lap at race pace on 26, 27.5 and 29 inch wheeled mountain bikes. sEMG and acceleration (RMS) were recorded for the full lap and during ascent and descent phases at the gastrocnemius, vastus lateralis, biceps brachii and triceps brachii. No significant main effects were found by wheel size for each of the four muscle groups for sEMG or acceleration during the full lap and for ascent and descent (P > .05). When data were analysed between muscle groups, significant differences were found between biceps brachii and triceps brachii (P biking. However, more activity was observed in the biceps brachii during 26 inch wheel descending. This is possibly due to an increased need to manoeuvre the front wheel over obstacles.

  8. The influence of lumbar extensor muscle fatigue on lumbar-pelvic coordination during weightlifting.

    Science.gov (United States)

    Hu, Boyi; Ning, Xiaopeng

    2015-01-01

    Lumbar muscle fatigue is a potential risk factor for the development of low back pain. In this study, we investigated the influence of lumbar extensor muscle fatigue on lumbar-pelvic coordination patterns during weightlifting. Each of the 15 male subjects performed five repetitions of weightlifting tasks both before and after a lumbar extensor muscle fatiguing protocol. Lumbar muscle electromyography was collected to assess fatigue. Trunk kinematics was recorded to calculate lumbar-pelvic continuous relative phase (CRP) and CRP variability. Results showed that fatigue significantly reduced the average lumbar-pelvic CRP value (from 0.33 to 0.29 rad) during weightlifting. The average CRP variability reduced from 0.17 to 0.15 rad, yet this change ws statistically not significant. Further analyses also discovered elevated spinal loading during weightlifting after the development of lumbar extensor muscle fatigue. Our results suggest that frequently experienced lumbar extensor muscle fatigue should be avoided in an occupational environment. Lumbar extensor muscle fatigue generates more in-phase lumbar-pelvic coordination patterns and elevated spinal loading during lifting. Such increase in spinal loading may indicate higher risk of back injury. Our results suggest that frequently experienced lumbar muscle fatigue should be avoided to reduce the risk of LBP.

  9. Housing system influences abundance of Pax3 and Pax7 in postnatal chicken skeletal muscles.

    Science.gov (United States)

    Yin, H D; Li, D Y; Zhang, L; Yang, M Y; Zhao, X L; Wang, Y; Liu, Y P; Zhu, Q

    2014-06-01

    Paired box (Pax) proteins 3 and 7 are associated with activation of muscle satellite cells and play a major role in hyperplastic and hypertrophic growth in postnatal skeletal muscle fibers. The objective of this study was to evaluate the effect of housing system on abundance of Pax3 and Pax7 in postnatal chicken skeletal muscles. At 42 d, 1,200 chickens with similar BW were randomly assigned to cage, pen, and free-range group. The mRNA abundance was measured in pectoralis major and thigh muscle at d 56, 70, and 84, and the protein expression was quantified at d 84. Increases in mRNA abundance of PAX3 and PAX7 with age were less pronounced in caged system chickens than in pen and free-range chickens from d 56 to 84, and free-range chickens showed a more pronounced increase in gene expression with age compared with penned chickens. At d 84, quantities of PAX3 and PAX7 mRNA and protein were highest in both pectoralis major and thigh muscle of chickens raised in the free-range group, lowest in penned chickens, and intermediate in caged chickens (P system may influence muscle fiber muscle accretion by coordinating the expression of Pax3 and Pax7 in adult chicken skeletal muscles. Poultry Science Association Inc.

  10. Mass media influence on students' professional illusion formation

    Directory of Open Access Journals (Sweden)

    Ermakov V.A.

    2016-11-01

    Full Text Available this article presents mass media activities as a possible source of professional socialization, adequateness of social process informative display in the sphere of young people professional identity. It describes pattern distortion of occupational structure, presents the problem of mass media inadequate influence on students’ understanding about the choice and perspectives of their profession. The main factors which help to create student’s understanding about their professional future are examined.

  11. Relative muscle mass and the risk of incident type 2 diabetes: A cohort study.

    Directory of Open Access Journals (Sweden)

    Sungwoo Hong

    Full Text Available The association between relative muscle mass (RMM and incidence of type 2 diabetes (T2DM is largely unknown. We examined whether RMM predicted development of T2DM in an apparently young healthy population.This cohort study was comprised of 113,913 men and 89,854 women, free of T2DM at baseline, who underwent a health checkup examination and were followed-up annually or biennially for an average of 2.9 years. We used skeletal muscle mass index (SMI as an indicator of RMM. SMI (% [total skeletal muscle mass (kg/body weight (kg×100] was estimated using a bioelectrical impedance analyzer. The study outcome was incident T2DM, defined as fasting serum glucose ≥126 mg/dL, HbA1C ≥6.5%, or use of medication for T2DM.During 589,098.8 person-years of follow-up, 4,264 individuals developed T2DM (incidence rate, 7.2 per 1000 person-years. Median age (range at baseline was 39.1 years (18.1-87.1. RMM was negatively associated with incidence of T2DM in a dose-response manner. The multivariate-adjusted hazard ratios (95% CIs for incident T2DM comparing quartiles 3, 2 and 1 of RMM to the highest quartile were 1.32 (1.14-1.52, 1.63 (1.42-1.86, and 2.21 (1.94-2.51, respectively, for males and 1.18 (0.88-1.58, 1.46 (1.11-1.91, and 1.96 (01.51-2.53 for females (P for trend <0.001; 0.011. This association was stronger in younger or premenopausal subjects.RMM was negatively associated with development of T2DM in a large sample of young and middle-aged Korean adults. Further research is required to determine whether preservation of muscle mass through intervention affects the risk of T2DM.

  12. Leg muscle mass and composition in relation to lower extremity performance in men and women aged 70 to 79 : the health, aging and body composition study

    NARCIS (Netherlands)

    Visser, Marjolein; Kritchevsky, Stephen B; Goodpaster, Bret H; Newman, Anne B; Nevitt, Michael; Stamm, Elizabeth; Harris, Tamara B

    OBJECTIVES: The loss of muscle mass with aging, or sarcopenia, is hypothesized to be associated with the deterioration of physical function. Our aim was to determine whether low leg muscle mass and greater fat infiltration in the muscle were associated with poor lower extremity performance (LEP).

  13. The effect of individualized nutritional counseling on muscle mass and treatment outcome in patients with metastatic colorectal cancer undergoing chemotherapy: a randomized controlled trial protocol

    NARCIS (Netherlands)

    van der Werf, Anne; Blauwhoff-Buskermolen, Susanne; Langius, Jacqueline A. E.; Berkhof, Johannes; Verheul, Henk M. W.; de van der Schueren, Marian A. E.

    2015-01-01

    A low muscle mass is prevalent in patients with metastatic colorectal cancer (mCRC) and has been associated with poor treatment outcome. Chemotherapeutic treatment has an additional unfavorable effect on muscle mass. Sufficient protein intake and physical activity are known to induce muscle protein

  14. Compensating effect of minor portal hypertension on the muscle mass loss-related poor prognosis in cirrhosis.

    Science.gov (United States)

    Maruyama, Hitoshi; Kobayashi, Kazufumi; Kiyono, Soichiro; Ogasawara, Sadahisa; Suzuki, Eichiro; Ooka, Yoshihiko; Chiba, Tetsuhiro; Yamaguchi, Tadashi

    2017-01-01

    Background: To examine the influence of the severity of portal hemodynamic abnormality on the prognosis of cirrhosis with respect to the muscle mass loss (MML). Methods: The study involved a subgroup analysis in 98 cirrhosis patients (63.5 ± 11.8 years) who prospectively underwent both Doppler ultrasound and hepatic venous catheterization. The prognostic influence of MML diagnosed by computed tomography using the L3 skeletal muscle index was evaluated (median observation period, 32.7 months). Results: The cumulative survival rate showed difference between patients with MML (n = 34; 82.2%/1year, 41.2%/3years and 36.1%/5years) and those without (n = 64; 92.1%/1year, 74.9%/3years and 69.4%/5years; P = 0.005). When divided with respect to the portal velocity, the survival rate showed differences between patients with and without MML in the cohort 12 mmHg. However, in the cohort with HVPG ≤ 12 mmHg, survival rate showed no difference between patients with MML (n=10; 100%/1year, 61.9%/3years and 61.9%/5years) and those without (n=19; 93.8%/1year, 71.2%/3years and 59.4%/5years; p = 0.493) Conclusion: Lower HVPG has a compensating effect on the MML-induced poor prognosis of cirrhosis. Care should be taken in the evaluation of the influence of MML in consideration of the severity of portal hypertension.

  15. Per meal dose and frequency of protein consumption is associated with lean mass and muscle performance.

    Science.gov (United States)

    Loenneke, Jeremy P; Loprinzi, Paul D; Murphy, Caoileann H; Phillips, Stuart M

    2016-12-01

    It has been hypothesized that for older adults evenly distributing consumption of protein at 30-40 g per meal throughout the day may result in more favorable retention of lean mass and muscular strength. Such a thesis has not, to our knowledge, been tested outside of short-term studies or acute measures of muscle protein synthesis. To examine whether the number of times an individual consumed a minimum of 30 g of protein at a meal is associated with leg lean mass and knee extensor strength. Data from the 1999-2002 NHANES were used, with 1081 adults (50-85 y) constituting the analytic sample. A "multiple pass" 24-h dietary interview format was used to collect detailed information about the participants' dietary intake. Knee extensor strength was assessed objectively using the Kin Com MP dynamometer. Leg lean mass was estimated from whole-body dual-energy X-ray absorptiometry (DXA) scans. Participants with 1 vs. 0 (β adjusted  = 23.6, p = 0.002) and 2 vs. 0 (β adjusted  = 51.1, p = 0.001) meals of ≥30 g protein/meal had greater strength and leg lean mass (1 vs. 0, β adjusted  = 1160, p frequency with leg lean mass and strength plateaued at ∼45 g protein/meal for those consuming 2 vs. 0 meals above the evaluated protein/meal threshold. However, for those with only 1 meal at or above the evaluated threshold, the response plateaued at 30 g/meal. Leg lean mass mediated the relationship between protein frequency and strength, with the proportion of the total effect mediated being 64%. We found that more frequent consumption of meals containing between 30 and 45 g protein/meal produced the greatest association with leg lean mass and strength. Thus, the consumption of 1-2 daily meals with protein content from 30 to 45 g may be an important strategy for increasing and/or maintaining lean body mass and muscle strength with aging. Copyright © 2016 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.

  16. Reduced bone mass and muscle strength in male 5α-reductase type 1 inactivated mice.

    Directory of Open Access Journals (Sweden)

    Sara H Windahl

    Full Text Available Androgens are important regulators of bone mass but the relative importance of testosterone (T versus dihydrotestosterone (DHT for the activation of the androgen receptor (AR in bone is unknown. 5α-reductase is responsible for the irreversible conversion of T to the more potent AR activator DHT. There are two well established isoenzymes of 5α-reductase (type 1 and type 2, encoded by separate genes (Srd5a1 and Srd5a2. 5α-reductase type 2 is predominantly expressed in male reproductive tissues whereas 5α-reductase type 1 is highly expressed in liver and moderately expressed in several other tissues including bone. The aim of the present study was to investigate the role of 5α-reductase type 1 for bone mass using Srd5a1⁻/⁻ mice. Four-month-old male Srd5a1⁻/⁻ mice had reduced trabecular bone mineral density (-36%, p<0.05 and cortical bone mineral content (-15%, p<0.05 but unchanged serum androgen levels compared with wild type (WT mice. The cortical bone dimensions were reduced in the male Srd5a1⁻/⁻ mice as a result of a reduced cortical periosteal circumference compared with WT mice. T treatment increased the cortical periosteal circumference (p<0.05 in orchidectomized WT mice but not in orchidectomized Srd5a1⁻/⁻ mice. Male Srd5a1⁻/⁻ mice demonstrated a reduced forelimb muscle grip strength compared with WT mice (p<0.05. Female Srd5a1⁻/⁻ mice had slightly increased cortical bone mass associated with elevated circulating levels of androgens. In conclusion, 5α-reductase type 1 inactivated male mice have reduced bone mass and forelimb muscle grip strength and we propose that these effects are due to lack of 5α-reductase type 1 expression in bone and muscle. In contrast, the increased cortical bone mass in female Srd5a1⁻/⁻ mice, is an indirect effect mediated by elevated circulating androgen levels.

  17. The influence of foot arch on ankle joint torques andon sEMG signal amplitude in selected lower leg muscles

    Directory of Open Access Journals (Sweden)

    Żebrowska Kinga

    2016-09-01

    Full Text Available Introduction: This study sought to assess the influence of proper foot arch on electromyographic activity of selected lower limb muscles. The aim of this work was to evaluate the effects of foot arch on the activity of selected muscles and to determine whether electromyography might help to identify types of flat feet resulting from muscle- or ligament-related causes.

  18. Resistance Exercise Impacts Lean Muscle Mass in Women with Polycystic Ovary Syndrome.

    Science.gov (United States)

    Kogure, Gislaine Satyko; Miranda-Furtado, Cristiana Libardi; Silva, Rafael Costa; Melo, Anderson Sanches; Ferriani, Rui Alberto; De Sá, Marcos Felipe Silva; Dos Reis, Rosana Maria

    2016-04-01

    This study investigated the effects of progressive resistance training (PRT) on lean muscle mass (LMM) in women with or without polycystic ovary syndrome (PCOS) and its effects on metabolic factors and concentrations of related steroid hormones. This was a nonrandomized, therapeutic, open, single-arm study. All in all, 45 sedentary women with PCOS and 52 without (non-PCOS), 18-37 yr of age, with body mass indexes (BMI) of 18-39.9 kg·m(-2) of all races and social status, performed PRT three times a week for 4 months. Before and after PRT, the concentrations of hormones and metabolic factors and waist circumference were measured. LMM and total body fat percentage were determined using dual-energy x-ray absorptiometry. Clinical characteristics, LMM, and fasting glucose were adjusted for confounding covariables and compared using general linear mixed models. Each patient's menstrual history was taken before study enrollment and after PRT. PRT resulted in reduced plasma testosterone and fasting glucose levels. After PRT, the androstenedione concentration increased and the sex hormone-binding globulin concentration decreased in women with PCOS. The waist circumference was reduced (P lean mass (LM)/height2, increased in women with PCOS (P = 0.04). Women with PCOS showed increased muscle mass indexes of appendicular LM/height2 (P = 0.03) and LM/height2 (P women with PCOS (P = 0.01) at the baseline and after PRT. To our knowledge, this is the first report to show that resistance exercise alone can improve hyperandrogenism, reproductive function, and body composition by decreasing visceral fat and increasing LMM, but it has no metabolic impact on women with PCOS.

  19. Is increase in bone mineral content caused by increase in skeletal muscle mass/strength in adult patients with GH-treated GH deficiency? A systematic literature analysis

    DEFF Research Database (Denmark)

    Klefter, O.; Feldt-Rasmussen, U.

    2009-01-01

    to a muscle modulating effect, and if treatment with GH would primarily increase muscle mass and strength with a secondary increase in BMD/BMC, thus supporting the present physiological concept that mass and strength of bones are mainly determined by dynamic loads from the skeletal muscles. METHOD: We...... performed a systematic literature analysis, including 51 clinical trials published between 1996 and 2008, which had studied the development in muscle mass, muscle strength, BMD, and/or BMC in GH-treated adult GHD patients. RESULTS: GH therapy had an anabolic effect on skeletal muscle. The largest increase...... in muscle mass occurred during the first 12 months of therapy. Most trials measuring BMD/BMC reported significant increases from baseline values. The significant increases in BMD/BMC occurred after 12-18 months of treatment, i.e. usually later than the increases in muscle parameters. Only seven trials...

  20. Is increase in bone mineral content caused by increase in skeletal muscle mass/strength in adult patients with GH-treated GH deficiency?

    DEFF Research Database (Denmark)

    Klefter, Oliver; Feldt-Rasmussen, Ulla

    2009-01-01

    to a muscle modulating effect, and if treatment with GH would primarily increase muscle mass and strength with a secondary increase in BMD/BMC, thus supporting the present physiological concept that mass and strength of bones are mainly determined by dynamic loads from the skeletal muscles. METHOD: We...... performed a systematic literature analysis, including 51 clinical trials published between 1996 and 2008, which had studied the development in muscle mass, muscle strength, BMD, and/or BMC in GH-treated adult GHD patients. RESULTS: GH therapy had an anabolic effect on skeletal muscle. The largest increase...... in muscle mass occurred during the first 12 months of therapy. Most trials measuring BMD/BMC reported significant increases from baseline values. The significant increases in BMD/BMC occurred after 12-18 months of treatment, i.e. usually later than the increases in muscle parameters. Only seven trials...

  1. A dietary supplementation with leucine and antioxidants is capable to accelerate muscle mass recovery after immobilization in adult rats.

    Directory of Open Access Journals (Sweden)

    Isabelle Savary-Auzeloux

    Full Text Available Prolonged inactivity induces muscle loss due to an activation of proteolysis and decreased protein synthesis; the latter is also involved in the recovery of muscle mass. The aim of the present work was to explore the evolution of muscle mass and protein metabolism during immobilization and recovery and assess the effect of a nutritional strategy for counteracting muscle loss and facilitating recovery. Adult rats (6-8 months were subjected to unilateral hindlimb casting for 8 days (I0-I8 and then permitted to recover for 10 to 40 days (R10-R40. They were fed a Control or Experimental diet supplemented with antioxidants/polyphenols (AOX (I0 to I8, AOX and leucine (AOX + LEU (I8 to R15 and LEU alone (R15 to R40. Muscle mass, absolute protein synthesis rate and proteasome activities were measured in gastrocnemius muscle in casted and non-casted legs in post prandial (PP and post absorptive (PA states at each time point. Immobilized gastrocnemius protein content was similarly reduced (-37% in both diets compared to the non-casted leg. Muscle mass recovery was accelerated by the AOX and LEU supplementation (+6% AOX+LEU vs. Control, P<0.05 at R40 due to a higher protein synthesis both in PA and PP states (+23% and 31% respectively, Experimental vs. Control diets, P<0.05, R40 without difference in trypsin- and chymotrypsin-like activities between diets. Thus, this nutritional supplementation accelerated the recovery of muscle mass via a stimulation of protein synthesis throughout the entire day (in the PP and PA states and could be a promising strategy to be tested during recovery from bed rest in humans.

  2. Relationship between lifting performance and skeletal muscle mass in elite powerlifters.

    Science.gov (United States)

    Ye, X; Loenneke, J P; Fahs, C A; Rossow, L M; Thiebaud, R S; Kim, D; Bemben, M G; Abe, T

    2013-08-01

    Aim of the study was to examine the relationship between whole body skeletal muscle mass (SMM) and powerlifting performance in elite powerlifters. Twenty elite male powerlifters, including 4 world champions, volunteered. Muscle thickness (MTH) and subcutaneous fat thickness (FTH) were measured by ultrasound at 9 sites on the anterior and posterior aspects of the body. FTH was used to estimate body fat and fat-free mass and SMM was estimated from ultrasound-derived prediction equations. Best lifting performance in the squat (SQ), bench press (BP), and dead lift (DL) was recorded from competition performance. Significant strong correlations (Pwide range of weight classes (56kg-145kg) and there were no significant correlation between the SMM and those performances (r=0.21 for SQ and r=0.12 for BP). However, the DL/SMM ratio was negatively correlated to DL performance (r=-0.47, P<0.05). SMM is a good predictor of powerlifting performance throughout all weight classes.

  3. INFLUENCE OF MASS GAIN DURING GESTATION ON MILK ...

    African Journals Online (AJOL)

    S. Afr. J. Anim ScL 4, 7l-74(1974). INFLUENCE OF MASS GAIN DURING GESTATION ON MILK PRODUCTION OF EWES. P. le Roux. Iubtopos Resarch Station, hivate Bag K 5137. Buhtttyo. Receipt of MS. 2.8.73. OPffiMMING; INVLOED VAN MASSATOENAUE GEDUREI{DE DRAGTIGHEID OP MELKPRODUKSIE vAN ...

  4. Influence of Bone and Muscle Injuries on the Osteogenic Potential of Muscle Progenitors: Contribution of Tissue Environment to Heterotopic Ossification.

    Science.gov (United States)

    Molligan, Jeremy; Mitchell, Reed; Schon, Lew; Achilefu, Samuel; Zahoor, Talal; Cho, Young; Loube, Jeffery; Zhang, Zijun

    2016-06-01

    : By using surgical mouse models, this study investigated how the tissue environment influences the osteogenic potential of muscle progenitors (m-progenitors) and potentially contributes to heterotopic ossification (HO). Injury was induced by clamping the gluteus maximus and medius (group M) or osteotomy of greater trochanter (group O) on the right hip, as well as combined muscle injury and osteotomy of greater trochanter (group M+O). The gluteus maximus and medius of the operated hips were harvested at days 1, 3, 5, and 10 for isolation of m-progenitors. The cells were cultured in an osteogenic medium for 3 weeks, and osteogenesis was evaluated by matrix mineralization and the expression of osteogenesis-related genes. The expression of type I collagen, RUNX2 (runt-related transcription factor 2), and osteocalcin by the m-progenitors of group M+O was significantly increased, compared with groups M and O. Osteogenic m-progenitors in group O increased the expression of bone morphogenetic protein 2 and also bone morphogenetic protein antagonist differential screening-selected gene aberrative in neuroblastoma. On histology, there was calcium deposition mostly in the muscles of group M+O harvested at day 10. CD56, representing myogenic progenitors, was highly expressed in the m-progenitors isolated from group M (day 10), but m-progenitors of group M+O (day 10) exhibited the highest expression of platelet-derived growth factor receptor α (PDGFR-α), a marker of muscle-derived mesenchymal stem cells (M-MSCs). The expressions of PDGFR-α and RUNX2 were colocalized in osteogenic m-progenitors. The data indicate that the tissue environment simulated in the M+O model is a favorable condition for HO formation. Most likely, M-MSCs, rather than myogenic progenitors, in the m-progenitors participate in HO formation. The prevalence of traumatic heterotopic ossification (HO) is high in war injury. The pathogenesis of HO is still unknown. This study clarified the contribution of a

  5. Influence of exercise and aging on extracellular matrix composition in the skeletal muscle stem cell niche.

    Science.gov (United States)

    Garg, Koyal; Boppart, Marni D

    2016-11-01

    Skeletal muscle is endowed with a remarkable capacity for regeneration, primarily due to the reserve pool of muscle resident satellite cells. The satellite cell is the physiologically quiescent muscle stem cell that resides beneath the basal lamina and adjacent to the sarcolemma. The anatomic location of satellite cells is in close proximity to vasculature where they interact with other muscle resident stem/stromal cells (e.g., mesenchymal stem cells and pericytes) through paracrine mechanisms. This mini-review describes the components of the muscle stem cell niche, as well as the influence of exercise and aging on the muscle stem cell niche. Although exercise promotes ECM reorganization and stem cell accumulation, aging is associated with dense ECM deposition and loss of stem cell function resulting in reduced regenerative capacity and strength. An improved understanding of the niche elements will be valuable to inform the development of therapeutic interventions aimed at improving skeletal muscle regeneration and adaptation over the life span. Copyright © 2016 the American Physiological Society.

  6. Low appendicular skeletal muscle mass (ASM) with limited mobility and poor health outcomes in middle-aged African Americans.

    Science.gov (United States)

    Malmstrom, Theodore K; Miller, Douglas K; Herning, Margaret M; Morley, John E

    2013-09-01

    Recent efforts to provide a consensus definition propose that sarcopenia be considered a clinical syndrome associated with the loss of both skeletal muscle mass and muscle function that occurs with aging. Validation of sarcopenia definitions that include both low muscle mass and poor muscle function is needed. In the population-based African American Health (AAH) study (N = 998 at baseline/wave 1), muscle mass and mobility were evaluated in a clinical testing center in a subsample of N = 319 persons (ages 52-68) at wave 4 (2004). Muscle mass was measured using dual energy x-ray absorptiometry and mobility by a 6-min walk test and 4-m gait walk test. Height corrected appendicular skeletal mass (ASM; 9.0 ± 1.5 in n = 124 males, 8.3 ± 2.2 in n = 195 females) was computed as total lean muscle mass in arms and legs (kilograms) divided by the square of height (meters). Cross-sectional and longitudinal (6-year) associations of low ASM (bottom 25 % AAH sample; ASM with limited mobility (4-m gait walk ≤1 m/s or 6-min walk ASM with limited mobility was associated with IADL difficulties (p = .008) and frailty (p = .040) but not with ADL difficulties or falls in cross-sectional analyses; and with ADL difficulties (p = .022), IADL difficulties (p = .006), frailty (p = .039), and mortality (p = .003) but not with falls in longitudinal analyses adjusted for age and gender. Low ASM alone was marginally associated with mortality (p = .085) but not with other outcomes in cross-sectional or longitudinal analyses. Low ASM with limited mobility is associated with poor health outcomes among late middle-aged African Americans.

  7. Sarcomere lattice geometry influences cooperative myosin binding in muscle.

    Directory of Open Access Journals (Sweden)

    Bertrand C W Tanner

    2007-07-01

    Full Text Available In muscle, force emerges from myosin binding with actin (forming a cross-bridge. This actomyosin binding depends upon myofilament geometry, kinetics of thin-filament Ca(2+ activation, and kinetics of cross-bridge cycling. Binding occurs within a compliant network of protein filaments where there is mechanical coupling between myosins along the thick-filament backbone and between actin monomers along the thin filament. Such mechanical coupling precludes using ordinary differential equation models when examining the effects of lattice geometry, kinetics, or compliance on force production. This study uses two stochastically driven, spatially explicit models to predict levels of cross-bridge binding, force, thin-filament Ca(2+ activation, and ATP utilization. One model incorporates the 2-to-1 ratio of thin to thick filaments of vertebrate striated muscle (multi-filament model, while the other comprises only one thick and one thin filament (two-filament model. Simulations comparing these models show that the multi-filament predictions of force, fractional cross-bridge binding, and cross-bridge turnover are more consistent with published experimental values. Furthermore, the values predicted by the multi-filament model are greater than those values predicted by the two-filament model. These increases are larger than the relative increase of potential inter-filament interactions in the multi-filament model versus the two-filament model. This amplification of coordinated cross-bridge binding and cycling indicates a mechanism of cooperativity that depends on sarcomere lattice geometry, specifically the ratio and arrangement of myofilaments.

  8. Creatine monohydrate supplementation does not increase muscle strength, lean body mass, or muscle phosphocreatine in patients with myotonic dystrophy type 1.

    Science.gov (United States)

    Tarnopolsky, Mark; Mahoney, Douglas; Thompson, Terry; Naylor, Heather; Doherty, Timothy J

    2004-01-01

    Creatine monohydrate (CrM) supplementation may increase strength in some types of muscular dystrophy. A recent study in myotonic muscular dystrophy type 1 (DM1) did not find a significant treatment effect, but measurements of muscle phosphocreatine (PCr) were not performed. We completed a randomized, double-blind, cross-over trial using 34 genetically confirmed adult DM1 patients without significant cognitive impairment. Participants received CrM (5 g, approximately 0.074 g/kg daily) and a placebo for each 4-month phase with a 6-week wash-out. Spirometry, manual muscle testing, quantitative isometric strength testing of handgrip, foot dorsiflexion, and knee extension, handgrip and foot dorsiflexion endurance, functional tasks, activity of daily living scales, body composition (total, bone, and fat-free mass), serum creatine kinase activity, serum creatinine concentration and clearance, and liver function tests were completed before and after each intervention, and muscle PCr/beta-adenosine triphosphate (ATP) ratios of the forearm flexor muscles were completed at the end of each phase. CrM supplementation did not increase any of the outcome measurements except for plasma creatinine concentration (but not creatinine clearance). Thus, CrM supplementation at 5 g daily does not have any effects on muscle strength, body composition, or activities of daily living in patients with DM1, perhaps because of a failure of the supplementation to increase muscle PCr/beta-ATP content.

  9. Genes Whose Gain or Loss-Of-Function Increases Skeletal Muscle Mass in Mice: A Systematic Literature Review

    Directory of Open Access Journals (Sweden)

    Sander A. J. Verbrugge

    2018-05-01

    Full Text Available Skeletal muscle mass differs greatly in mice and humans and this is partially inherited. To identify muscle hypertrophy candidate genes we conducted a systematic review to identify genes whose experimental loss or gain-of-function results in significant skeletal muscle hypertrophy in mice. We found 47 genes that meet our search criteria and cause muscle hypertrophy after gene manipulation. They are from high to small effect size: Ski, Fst, Acvr2b, Akt1, Mstn, Klf10, Rheb, Igf1, Pappa, Ppard, Ikbkb, Fstl3, Atgr1a, Ucn3, Mcu, Junb, Ncor1, Gprasp1, Grb10, Mmp9, Dgkz, Ppargc1a (specifically the Ppargc1a4 isoform, Smad4, Ltbp4, Bmpr1a, Crtc2, Xiap, Dgat1, Thra, Adrb2, Asb15, Cast, Eif2b5, Bdkrb2, Tpt1, Nr3c1, Nr4a1, Gnas, Pld1, Crym, Camkk1, Yap1, Inhba, Tp53inp2, Inhbb, Nol3, Esr1. Knock out, knock down, overexpression or a higher activity of these genes causes overall muscle hypertrophy as measured by an increased muscle weight or cross sectional area. The mean effect sizes range from 5 to 345% depending on the manipulated gene as well as the muscle size variable and muscle investigated. Bioinformatical analyses reveal that Asb15, Klf10, Tpt1 are most highly expressed hypertrophy genes in human skeletal muscle when compared to other tissues. Many of the muscle hypertrophy-regulating genes are involved in transcription and ubiquitination. Especially genes belonging to three signaling pathways are able to induce hypertrophy: (a Igf1-Akt-mTOR pathway, (b myostatin-Smad signaling, and (c the angiotensin-bradykinin signaling pathway. The expression of several muscle hypertrophy-inducing genes and the phosphorylation of their protein products changes after human resistance and high intensity exercise, in maximally stimulated mouse muscle or in overloaded mouse plantaris.

  10. Relation between body mass index percentile and muscle strength and endurance

    Directory of Open Access Journals (Sweden)

    Noha Abdel Kader Abdel Kader Hasan

    2016-10-01

    Conclusion: The study shows that the BMI of children had a positive correlation with the muscle strength of quadriceps, triceps, and abdominal muscles while a negative correlation with the endurance time of these muscles.

  11. The relationship between passive stiffness and evoked twitch properties: the influence of muscle CSA normalization

    International Nuclear Information System (INIS)

    Ryan, E D; Thompson, B J; Sobolewski, E J; Herda, T J; Costa, P B; Walter, A A; Cramer, J T

    2011-01-01

    Passive stiffness measurements are often used as a clinical tool to examine a muscle's passive lengthening characteristics. The purpose of this study was to examine the relationship between passive stiffness and evoked twitch properties prior to and following normalization of passive stiffness to muscle cross-sectional area (CSA). Ten healthy volunteers (mean ± SD age = 23 ± 3 year) performed passive range of motion, evoked twitch, and muscle CSA assessments of the plantar flexor muscles. Passive stiffness was determined from the slope of the final 5° of the angle–torque curve. Peak twitch torque (PTT) and rate of torque development (RTD) were determined via transcutaneous electrical stimulation, and muscle CSA was assessed using a peripheral quantitative computed tomography scanner. Pearson product moment correlation coefficients (r) were used to assess the relationships between passive stiffness and PTT and RTD and normalized passive stiffness (passive stiffness . muscle CSA −1 ) and PTT and RTD. Significant positive relationships were observed between passive stiffness and PTT (P = 0.003, r = 0.828) and RTD (P = 0.003, r = 0.825). There were no significant relationships between normalized passive stiffness and PTT (P = 0.290, r = 0.372) or RTD (P = 0.353, r = 0.329) demonstrating that stiffness did not account for a significant portion of the variance in twitch properties. Passive stiffness was largely influenced by the amount of muscle tissue in this study. Future studies that examine muscle stiffness and its relationship with performance measures, among different populations, and following various interventions may consider normalizing stiffness measurements to muscle CSA

  12. The influence of wheelchair propulsion technique on upper extremity muscle demand: a simulation study.

    Science.gov (United States)

    Rankin, Jeffery W; Kwarciak, Andrew M; Richter, W Mark; Neptune, Richard R

    2012-11-01

    The majority of manual wheelchair users will experience upper extremity injuries or pain, in part due to the high force requirements, repetitive motion and extreme joint postures associated with wheelchair propulsion. Recent studies have identified cadence, contact angle and peak force as important factors for reducing upper extremity demand during propulsion. However, studies often make comparisons between populations (e.g., able-bodied vs. paraplegic) or do not investigate specific measures of upper extremity demand. The purpose of this study was to use a musculoskeletal model and forward dynamics simulations of wheelchair propulsion to investigate how altering cadence, peak force and contact angle influence individual muscle demand. Forward dynamics simulations of wheelchair propulsion were generated to emulate group-averaged experimental data during four conditions: 1) self-selected propulsion technique, and while 2) minimizing cadence, 3) maximizing contact angle, and 4) minimizing peak force using biofeedback. Simulations were used to determine individual muscle mechanical power and stress as measures of muscle demand. Minimizing peak force and cadence had the lowest muscle power requirements. However, minimizing peak force increased cadence and recovery power, while minimizing cadence increased average muscle stress. Maximizing contact angle increased muscle stress and had the highest muscle power requirements. Minimizing cadence appears to have the most potential for reducing muscle demand and fatigue, which could decrease upper extremity injuries and pain. However, altering any of these variables to extreme values appears to be less effective; instead small to moderate changes may better reduce overall muscle demand. Copyright © 2012 Elsevier Ltd. All rights reserved.

  13. The Influence of Ambulatory Aid on Lower-Extremity Muscle Activation During Gait.

    Science.gov (United States)

    Sanders, Michael; Bowden, Anton E; Baker, Spencer; Jensen, Ryan; Nichols, McKenzie; Seeley, Matthew K

    2018-05-10

    Foot and ankle injuries are common and often require a nonweight-bearing period of immobilization for the involved leg. This nonweight-bearing period usually results in muscle atrophy for the involved leg. There is a dearth of objective data describing muscle activation for different ambulatory aids that are used during the aforementioned nonweight-bearing period. To compare activation amplitudes for 4 leg muscles during (1) able-bodied gait and (2) ambulation involving 3 different ambulatory aids that can be used during the acute phase of foot and ankle injury care. Within-subject, repeated measures. University biomechanics laboratory. Sixteen able-bodied individuals (7 females and 9 males). Each participant performed able-bodied gait and ambulation using 3 different ambulatory aids (traditional axillary crutches, knee scooter, and a novel lower-leg prosthesis). Muscle activation amplitude quantified via mean surface electromyography amplitude throughout the stance phase of ambulation. Numerous statistical differences (P < .05) existed for muscle activation amplitude between the 4 observed muscles, 3 ambulatory aids, and able-bodied gait. For the involved leg, comparing the 3 ambulatory aids: (1) knee scooter ambulation resulted in the greatest vastus lateralis activation, (2) ambulation using the novel prosthesis and traditional crutches resulted in greater biceps femoris activation than knee scooter ambulation, and (3) ambulation using the novel prosthesis resulted in the greatest gastrocnemius activation (P < .05). Generally speaking, muscle activation amplitudes were most similar to able-bodied gait when subjects were ambulating using the knee scooter or novel prosthesis. Type of ambulatory aid influences muscle activation amplitude. Traditional axillary crutches appear to be less likely to mitigate muscle atrophy during the nonweighting, immobilization period that often follows foot or ankle injuries. Researchers and clinicians should consider

  14. Prognostic significance of low skeletal muscle mass compared with protein-energy malnutrition in liver cirrhosis.

    Science.gov (United States)

    Nishikawa, Hiroki; Enomoto, Hirayuki; Ishii, Akio; Iwata, Yoshinori; Miyamoto, Yuho; Ishii, Noriko; Yuri, Yukihisa; Takata, Ryo; Hasegawa, Kunihiro; Nakano, Chikage; Nishimura, Takashi; Yoh, Kazunori; Aizawa, Nobuhiro; Sakai, Yoshiyuki; Ikeda, Naoto; Takashima, Tomoyuki; Iijima, Hiroko; Nishiguchi, Shuhei

    2017-09-01

    To investigate the impact of low skeletal muscle mass (LSMM) on survival as compared with protein-energy malnutrition (PEM) in patients with liver cirrhosis (LC). A total of 206 individuals with LC were analyzed. We retrospectively examined the impact of LSMM, as defined by psoas muscle mass at the third lumber on computed tomography, on survival as compared with PEM. In terms of comparison of the effects of LSMM and PEM on survival, we used time-dependent receiver operating characteristics (ROC) analysis. Our study cohort included 115 men and 91 women with a median age of 67 years. There were 140 patients with Child-Pugh A, 62 with Child-Pugh B, and 4 with Child-Pugh C. A total of 117 patients (56.8%) had LSMM and 52 patients (25.2%) had PEM. The proportion of PEM in patients with LSMM (31.62%, 37/117) was significantly higher than in patients without LSMM (16.85%, 15/89) (P = 0.0229). In the multivariate analysis for the entire cohort, the presence of hepatocellular carcinoma, lower body mass index, presence of LSMM, lower triglyceride value, poorer renal function, and higher des-γ-carboxy prothrombin value were found to be significant adverse predictors linked to overall survival, while presence of PEM tended to be significant. In the time-dependent ROC analysis, all area under the ROCs for survival in LSMM at each time point were higher than those in PEM except for Child-Pugh B patients. In this comparison of LSMM and PEM on clinical outcomes in LC patients, it was shown that LSMM may have stronger prognostic impact than PEM. © 2016 The Japan Society of Hepatology.

  15. The Effect of a 12-Week Omega-3 Supplementation on Body Composition, Muscle Strength and Physical Performance in Elderly Individuals with Decreased Muscle Mass

    Directory of Open Access Journals (Sweden)

    Roma Krzymińska-Siemaszko

    2015-08-01

    Full Text Available The aim of the study was to assess the effect of a polyunsaturated omega-3 fatty acids (PUFA supplementation on the parameters of body composition, muscle strength and physical performance in elderly people with decreased muscle mass (DMM. Fifty three elderly people with an ALM index (the ratio of appendicular lean mass to squared height either below (−2SD: low muscle mass-LMM or between (−1SD and −2SD: the risk of LMM-rLMM the ALM index for the young Polish reference population were randomly assigned to PUFA-treated groups (LMM-PUFA, rLMM-PUFA or control groups (LMM-control, rLMM-control. PUFA-treated groups received capsules containing 1.3 g of PUFA and 10 mg of vitamin E, while the control groups received 11 mg of vitamin E daily for 12 weeks. Body composition (BIA analysis, muscle strength (hand grip measured with dynamometer and physical performance (Timed Up and Go test-TUG were assessed before and after supplementation. No statistically significant differences were observed either in muscle mass or in the hand grip and TUG in any group. The post-pre difference (mean ± SD in ALM index was as follows (kg/m2: LMM-PUFA: 0.00 ± 0.30, rLMM-PUFA: 0.00 ± 0.22, LMM-control: 0.03 ± 0.36, rLMM-control: –0.03 ± 0.20. In our study, a 12 week supplementation of PUFA did not affect the evaluated parameters in elderly individuals with DMM.

  16. Associations between lower extremity muscle mass and metabolic parameters related to obesity in Japanese obese patients with type 2 diabetes

    Directory of Open Access Journals (Sweden)

    Hidetaka Hamasaki

    2015-05-01

    Full Text Available Background. Age-related loss of muscle mass (sarcopenia increases the incidence of obesity in the elderly by reducing physical activity. This sarcopenic obesity may become self-perpetuating, increasing the risks for metabolic syndrome, disability, and mortality. We investigated the associations of two sarcopenic indices, the ratio of lower extremity muscle mass to body weight (L/W ratio and the ratio of lower extremity muscle mass to upper extremity muscle mass (L/U ratio, with metabolic parameters related to obesity in patients with type 2 diabetes and obesity.Methods. Of 148 inpatients with type 2 diabetes treated between October 2013 and April 2014, we recruited 26 with obesity but no physical disability. Daily physical activity was measured by a triaxial accelerometer during a period of hospitalization, and which was also evaluated by our previously reported non-exercise activity thermogenesis questionnaire. We measured body composition by bioelectrical impedance and investigated the correlations of L/W and L/U ratios with body weight, body mass index (BMI, waist circumference (WC, waist-to-hip ratio (WHR, visceral fat area, subcutaneous fat area, serum lipid profile, and daily physical activity.Results. The L/W ratio was significantly and negatively correlated with BMI, WC, WHR, body fat mass, body fat percentage, subcutaneous fat area, and serum free fatty acid concentration, was positively correlated with daily physical activity: the locomotive non-exercise activity thermogenesis score, but was not correlated with visceral fat area. The L/U ratio was significantly and positively correlated with serum high-density lipoprotein cholesterol.Conclusions. High L/W and L/U ratios, indicative of relatively preserved lower extremity muscle mass, were predictive of improved metabolic parameters related to obesity. Preserved muscle fitness in obesity, especially of the lower extremities, may prevent sarcopenic obesity and lower associated risks for

  17. Low skeletal muscle mass outperforms the Charlson Comorbidity Index in risk prediction in patients undergoing pancreatic resections.

    Science.gov (United States)

    Wagner, D; Marsoner, K; Tomberger, A; Haybaeck, J; Haas, J; Werkgartner, G; Cerwenka, H; Bacher, H; Mischinger, H J; Kornprat, P

    2018-05-01

    Low skeletal muscle mass is a known predictor of morbidity and mortality in patients undergoing major pancreatic surgeries. We sought to combine low skeletal muscle mass with established risk predictors to improve their prognostic capacity for postoperative outcome and morbidity. As established parameters to predict preoperative mortality risk for patients, the ASA classification and the Charlson Comorbidity Index (CCI) were used. The Hounsfield Units Average Calculation (HUAC) was measured to define low skeletal muscle mass in 424 patients undergoing pancreatic resections for malignancies. Patients in the lowest sex-adjusted quartile for HUAC were defined as having low skeletal muscle mass (muscle wasting). Multivariable Cox regression analysis was utilized to identify preoperative risk factors associated with postoperative morbidity. Median patient age was 63 years (19-87), 47.9% patients were male, and half the cohort had multiple comorbidities (Charlson Comorbidity Index [CCI]>6, 63.2%), 30-day mortality was 5.8% (n = 25). Median HUAC was 19.78 HU (IQR: 15.94-23.54) with 145 patients (34.2%) having low skeletal muscle mass. Preoperative frailty defined by low skeletal muscle mass was associated with an increased risk for postoperative complications (OR 1.55, CI 95% 0.98-2.45, p = 0.014), and a higher 30-day mortality (HR 5.17, CI 95% 1.57-16.69, p = 0.004). With an AUC of 0.85 HUAC showed the highest predictability for 30-day mortality (CI 95% 0.78-0.91, p = 0.0001). Patients with CCI ≥6 and low skeletal muscle mass defined by the HUAC had a 9.78 higher risk of dying in the immediate postoperative phase (HR 9.78, CI 95% 2.98-12.2, p = 0.0001). Low skeletal muscle mass predicts postoperative mortality and complications best and it should be incorporated to conventional risk scores to identify high risk patients. Copyright © 2018 Elsevier Ltd, BASO ~ The Association for Cancer Surgery, and the European Society of Surgical Oncology. All rights

  18. Effects of progressive strength training on muscle mass in type 2 diabetes mellitus patients determined by computed tomography

    International Nuclear Information System (INIS)

    Cauza, E.; Strehblow, C.; Hanusch-Enserer, U.; Fasching, P.; Metz-Schimmerl, S.; Strasser, B.; Kostner, K.; Dunstan, D.; Haber, P.

    2009-01-01

    To examine the effect of a 4-month progressive strength training program on muscle and fat mass assessed by computed tomography (CT) in type 2 diabetes mellitus (T2DM) patients, and to assess the relationships of changes in muscle cross-section area (CSA) with glycaemic control. Twenty adults (mean age ± SE: 56.4 ± 0.9 a) with T2DM participated in a supervised strength training program for 4 months 3 days/week. Muscle and fat areas of the quadriceps muscle were estimated by CT volumetry before and immediately after the training. Glycaemic (HbA1c) and anthropometric (BMI, skinfolds) measurements were assessed at 0 and 4 months, respectively. After strength training, muscle strength increased significantly in all measured muscle groups. Quadriceps size (CSA of the muscle) was increased by 2.4 % (from 7.99 ± 0.3 cm 3 to 8.18 ± 0.3 cm 3 , p = 0.003) for the right extremity, 3.9 % (from 8.1 ± 0.4 cm 3 to 8.41 ± 0.5 cm 3 , p = 0.04) for the left side. Fat tissue CSA reduced from 0.66 ± 0.1 cm 3 to 0.56 ± 0.12 cm 3 for the right leg (15.3 % reduction) and from 0.58 ± 0.12 cm 3 to 0.37 ± 0.13 cm 3 for the left leg (35.8 % reduction), resulting in a mean fat CSA reduction of 24.8 %. Fat mass assessed by skin folds was significantly reduced and lean body mass was significantly increased. The change in muscle CSA was not correlated with the changes in HbA1c or muscle strength. Strength training significantly improves both muscle mass and the muscle to fat ratio in T2DM. However, changes in muscle observed with computed tomography were not related to changes observed in HbA1c with training. (author) [de

  19. Inferring Social Influence of Anti-Tobacco Mass Media Campaign.

    Science.gov (United States)

    Zhan, Qianyi; Zhang, Jiawei; Yu, Philip S; Emery, Sherry; Xie, Junyuan

    2017-07-01

    Anti-tobacco mass media campaigns are designed to influence tobacco users. It has been proved that campaigns will produce users' changes in awareness, knowledge, and attitudes, and also produce meaningful behavior change of audience. Anti-smoking television advertising is the most important part in the campaign. Meanwhile, nowadays, successful online social networks are creating new media environment, however, little is known about the relation between social conversations and anti-tobacco campaigns. This paper aims to infer social influence of these campaigns, and the problem is formally referred to as the Social Influence inference of anti-Tobacco mass mEdia campaigns (Site) problem. To address the Site problem, a novel influence inference framework, TV advertising social influence estimation (Asie), is proposed based on our analysis of two real anti-tobacco campaigns. Asie divides audience attitudes toward TV ads into three distinct stages: 1) cognitive; 2) affective; and 3) conative. Audience online reactions at each of these three stages are depicted by Asie with specific probabilistic models based on the synergistic influences from both online social friends and offline TV ads. Extensive experiments demonstrate the effectiveness of Asie.

  20. Phenotype selection reveals coevolution of muscle glycogen and protein and PTEN as a gate keeper for the accretion of muscle mass in adult female mice.

    Directory of Open Access Journals (Sweden)

    Mandy Sawitzky

    Full Text Available We have investigated molecular mechanisms for muscle mass accretion in a non-inbred mouse model (DU6P mice characterized by extreme muscle mass. This extreme muscle mass was developed during 138 generations of phenotype selection for high protein content. Due to the repeated trait selection a complex setting of different mechanisms was expected to be enriched during the selection experiment. In muscle from 29-week female DU6P mice we have identified robust increases of protein kinase B activation (AKT, Ser-473, up to 2-fold if compared to 11- and 54-week DU6P mice or controls. While a number of accepted effectors of AKT activation, including IGF-I, IGF-II, insulin/IGF-receptor, myostatin or integrin-linked kinase (ILK, were not correlated with this increase, phosphatase and tensin homologue deleted on chromosome 10 (PTEN was down-regulated in 29-week female DU6P mice. In addition, higher levels of PTEN phosphorylation were found identifying a second mechanism of PTEN inhibition. Inhibition of PTEN and activation of AKT correlated with specific activation of p70S6 kinase and ribosomal protein S6, reduced phosphorylation of eukaryotic initiation factor 2α (eIF2α and higher rates of protein synthesis in 29-week female DU6P mice. On the other hand, AKT activation also translated into specific inactivation of glycogen synthase kinase 3ß (GSK3ß and an increase of muscular glycogen. In muscles from 29-week female DU6P mice a significant increase of protein/DNA was identified, which was not due to a reduction of protein breakdown or to specific increases of translation initiation. Instead our data support the conclusion that a higher rate of protein translation is contributing to the higher muscle mass in mid-aged female DU6P mice. Our results further reveal coevolution of high protein and high glycogen content during the selection experiment and identify PTEN as gate keeper for muscle mass in mid-aged female DU6P mice.

  1. Usefulness of circuit training at home for improving bone mass and muscle mass while losing fat mass in undergraduate female students.

    Science.gov (United States)

    Takahata, Yoko

    2018-05-09

    The purpose of this study was to determine whether or not circuit training at home affects the calcaneus quantitative ultrasound status as well as other indices of body composition among undergraduate female students. Forty-one adolescents were recruited (18.5 ± 0.6 years old). The stiffness index of the calcaneus, broadband ultrasound attenuation of the calcaneus, speed of sound of the calcaneus, and body frame index. This was a three-month intervention study, so the measurements were conducted at baseline, 2 months later, and 3 months later while the subjects underwent circuit training at home. The subjects were divided into two groups: namely, the exercising group and non-exercising group. In the exercising group, broadband ultrasound attenuation of the calcaneus was higher 2 months later (p = 0.033) as well as 3 months later (p = 0.036), and the speed of sound of the calcaneus was higher 3 months later (p = 0.018). In addition, the muscle mass was strongly positively correlated with the calcaneus QUS-SOS (p = 0.004), while the body fat percentage was a strongly negatively correlated with the calcaneus QUS-BUA (p = 0.043). In the non-exercising group, the stiffness index of the calcaneus was higher 2 months later (p = 0.002) as well as 3 months later (p = 0.002). Furthermore, the body percentage was strongly positively correlated with the calcaneus QUS-SI (p = 0.009). These findings suggest that the calcaneus quantitative ultrasound status and muscle mass while losing fat mass may be improved by means of a simple exercise regimen within a short period among undergraduate female students.

  2. Age-Associated Loss of OPA1 in Muscle Impacts Muscle Mass, Metabolic Homeostasis, Systemic Inflammation, and Epithelial Senescence.

    Science.gov (United States)

    Tezze, Caterina; Romanello, Vanina; Desbats, Maria Andrea; Fadini, Gian Paolo; Albiero, Mattia; Favaro, Giulia; Ciciliot, Stefano; Soriano, Maria Eugenia; Morbidoni, Valeria; Cerqua, Cristina; Loefler, Stefan; Kern, Helmut; Franceschi, Claudio; Salvioli, Stefano; Conte, Maria; Blaauw, Bert; Zampieri, Sandra; Salviati, Leonardo; Scorrano, Luca; Sandri, Marco

    2017-06-06

    Mitochondrial dysfunction occurs during aging, but its impact on tissue senescence is unknown. Here, we find that sedentary but not active humans display an age-related decline in the mitochondrial protein, optic atrophy 1 (OPA1), that is associated with muscle loss. In adult mice, acute, muscle-specific deletion of Opa1 induces a precocious senescence phenotype and premature death. Conditional and inducible Opa1 deletion alters mitochondrial morphology and function but not DNA content. Mechanistically, the ablation of Opa1 leads to ER stress, which signals via the unfolded protein response (UPR) and FoxOs, inducing a catabolic program of muscle loss and systemic aging. Pharmacological inhibition of ER stress or muscle-specific deletion of FGF21 compensates for the loss of Opa1, restoring a normal metabolic state and preventing muscle atrophy and premature death. Thus, mitochondrial dysfunction in the muscle can trigger a cascade of signaling initiated at the ER that systemically affects general metabolism and aging. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.

  3. Ratio of muscle mass to fat mass assessed by bioelectrical impedance analysis is significantly correlated with liver fat accumulation in patients with type 2 diabetes mellitus.

    Science.gov (United States)

    Kurinami, Noboru; Sugiyama, Seigo; Morita, Ayami; Yoshida, Akira; Hieshima, Kunio; Miyamoto, Fumio; Kajiwara, Keizo; Jinnouch, Katsunori; Jinnouchi, Tomio; Jinnouchi, Hideaki

    2018-05-01

    Obesity and ectopic fat accumulation are important conditions of type 2 diabetes mellitus (T2DM). Our aim was to determine whether bioelectrical impedance body composition analysis combined with blood test results could estimate liver ectopic fat accumulation in patients with treatment-naïve T2DM. Subjects were 119 untreated T2DM patients. Computed tomography scans were performed to calculate the liver to spleen attenuation ratio (L/S ratio) as a measure of liver fat accumulation, with excess liver fat accumulation defined as an L/S ratio analysis using InBody770. The Nagelkerke R 2 test showed that the muscle mass/fat mass ratio (muscle/fat ratio) was the most suitable variable among anthropometric factors and body component indexes for estimating liver fat accumulation. The muscle/fat ratio was significantly correlated with the L/S ratio (ρ = 0.4386, P analysis showed that the muscle/fat ratio (odds ratio 0.40, 95% confidence interval 0.22-0.73, P ratio 1.06, 95% confidence interval 1.02-1.10, P analysis, the cutoff value of the muscle/fat ratio for excess liver fat accumulation was 2.34. In patients with treatment-naïve T2DM, the muscle/fat ratio and ALT are useful for estimating the presence of excess liver fat accumulation in daily clinical practice. Copyright © 2018. Published by Elsevier B.V.

  4. Motor unit recruitment strategies and muscle properties determine the influence of synaptic noise on force steadiness

    Science.gov (United States)

    Dideriksen, Jakob L.; Negro, Francesco; Enoka, Roger M.

    2012-01-01

    Motoneurons receive synaptic inputs from tens of thousands of connections that cause membrane potential to fluctuate continuously (synaptic noise), which introduces variability in discharge times of action potentials. We hypothesized that the influence of synaptic noise on force steadiness during voluntary contractions is limited to low muscle forces. The hypothesis was examined with an analytical description of transduction of motor unit spike trains into muscle force, a computational model of motor unit recruitment and rate coding, and experimental analysis of interspike interval variability during steady contractions with the abductor digiti minimi muscle. Simulations varied contraction force, level of synaptic noise, size of motor unit population, recruitment range, twitch contraction times, and level of motor unit short-term synchronization. Consistent with the analytical derivations, simulations and experimental data showed that force variability at target forces above a threshold was primarily due to low-frequency oscillations in neural drive, whereas the influence of synaptic noise was almost completely attenuated by two low-pass filters, one related to convolution of motoneuron spike trains with motor unit twitches (temporal summation) and the other attributable to summation of single motor unit forces (spatial summation). The threshold force above which synaptic noise ceased to influence force steadiness depended on recruitment range, size of motor unit population, and muscle contractile properties. This threshold was low (motor unit recruitment and muscle properties of a typical muscle are tuned to limit the influence of synaptic noise on force steadiness to low forces and that the inability to produce a constant force during stronger contractions is mainly attributable to the common low-frequency oscillations in motoneuron discharge rates. PMID:22423000

  5. Park7 expression influences myotube size and myosin expression in muscle.

    Directory of Open Access Journals (Sweden)

    Hui Yu

    Full Text Available Callipyge sheep exhibit postnatal muscle hypertrophy due to the up-regulation of DLK1 and/or RTL1. The up-regulation of PARK7 was identified in hypertrophied muscles by microarray analysis and further validated by quantitative PCR. The expression of PARK7 in hypertrophied muscle of callipyge lambs was confirmed to be up-regulated at the protein level. PARK7 was previously identified to positively regulate PI3K/AKT pathway by suppressing the phosphatase activity of PTEN in mouse fibroblasts. The purpose of this study was to investigate the effects of PARK7 in muscle growth and protein accretion in response to IGF1. Primary myoblasts isolated from Park7 (+/+ and Park7 (-/- mice were used to examine the effect of differential expression of Park7. The Park7 (+/+ myotubes had significantly larger diameters and more total sarcomeric myosin expression than Park7 (-/- myotubes. IGF1 treatment increased the mRNA abundance of Myh4, Myh7 and Myh8 between 20-40% in Park7 (+/+ myotubes relative to Park7 (-/-. The level of AKT phosphorylation was increased in Park7 (+/+ myotubes at all levels of IGF1 supplementation. After removal of IGF1, the Park7 (+/+ myotubes maintained higher AKT phosphorylation through 3 hours. PARK7 positively regulates the PI3K/AKT pathway by inhibition of PTEN phosphatase activity in skeletal muscle. The increased PARK7 expression can increase protein synthesis and result in myotube hypertrophy. These results support the hypothesis that elevated expression of PARK7 in callipyge muscle would increase levels of AKT activity to cause hypertrophy in response to the normal IGF1 signaling in rapidly growing lambs. Increasing expression of PARK7 could be a novel mechanism to increase protein accretion and muscle growth in livestock or help improve muscle mass with disease or aging.

  6. Imaging mass spectrometry reveals fiber-specific distribution of acetylcarnitine and contraction-induced carnitine dynamics in rat skeletal muscles.

    Science.gov (United States)

    Furuichi, Yasuro; Goto-Inoue, Naoko; Manabe, Yasuko; Setou, Mitsutoshi; Masuda, Kazumi; Fujii, Nobuharu L

    2014-10-01

    Carnitine is well recognized as a key regulator of long-chain fatty acyl group translocation into the mitochondria. In addition, carnitine, as acetylcarnitine, acts as an acceptor of excess acetyl-CoA, a potent inhibitor of pyruvate dehydrogenase. Here, we provide a new methodology for accurate quantification of acetylcarnitine content and determination of its localization in skeletal muscles. We used matrix-assisted laser desorption/ionization imaging mass spectrometry (MALDI-IMS) to visualize acetylcarnitine distribution in rat skeletal muscles. MALDI-IMS and immunohistochemistry of serial cross-sections showed that acetylcarnitine was enriched in the slow-type muscle fibers. The concentration of ATP was lower in muscle regions with abundant acetylcarnitine, suggesting a relationship between acetylcarnitine and metabolic activity. Using our novel method, we detected an increase in acetylcarnitine content after muscle contraction. Importantly, this increase was not detected using traditional biochemical assays of homogenized muscles. We also demonstrated that acetylation of carnitine during muscle contraction was concomitant with glycogen depletion. Our methodology would be useful for the quantification of acetylcarnitine and its contraction-induced kinetics in skeletal muscles. Copyright © 2014 Elsevier B.V. All rights reserved.

  7. Sociocultural and Individual Influences on Muscle Gain and Weight Loss Strategies among Adolescent Boys and Girls

    Science.gov (United States)

    Ricciardelli, Lina A.; McCabe, Marita P.

    2003-01-01

    The study examined the role of body dissatisfaction, body image importance, sociocultural influences (media and parent and peer encouragement), self-esteem and negative affect on body change strategies to decrease weight and increase muscles in adolescent boys and girls. Surveys were administered to 587 boys and 598 girls aged between 11 and 15…

  8. Influence of Lumbar Muscle Fatigue on Trunk Adaptations during Sudden External Perturbations

    Science.gov (United States)

    Abboud, Jacques; Nougarou, François; Lardon, Arnaud; Dugas, Claude; Descarreaux, Martin

    2016-01-01

    Introduction: When the spine is subjected to perturbations, neuromuscular responses such as reflex muscle contractions contribute to the overall balance control and spinal stabilization mechanisms. These responses are influenced by muscle fatigue, which has been shown to trigger changes in muscle recruitment patterns. Neuromuscular adaptations, e.g., attenuation of reflex activation and/or postural oscillations following repeated unexpected external perturbations, have also been described. However, the characterization of these adaptations still remains unclear. Using high-density electromyography (EMG) may help understand how the nervous system chooses to deal with an unknown perturbation in different physiological and/or mechanical perturbation environments. Aim: To characterize trunk neuromuscular adaptations following repeated sudden external perturbations after a back muscle fatigue task using high-density EMG. Methods: Twenty-five healthy participants experienced a series of 15 sudden external perturbations before and after back muscle fatigue. Erector spinae muscle activity was recorded using high-density EMG. Trunk kinematics during perturbation trials were collected using a 3-D motion analysis system. A two-way repeated measure ANOVA was conducted to assess: (1) the adaptation effect across trials; (2) the fatigue effect; and (3) the interaction effect (fatigue × adaptation) for the baseline activity, the reflex latency, the reflex peak and trunk kinematic variables (flexion angle, velocity and time to peak velocity). Muscle activity spatial distribution before and following the fatigue task was also compared using t-tests for dependent samples. Results: An attenuation of muscle reflex peak was observed across perturbation trials before the fatigue task, but not after. The spatial distribution of muscle activity was significantly higher before the fatigue task compared to post-fatigue trials. Baseline activity showed a trend to higher values after muscle

  9. Influence of lumbar muscle fatigue on trunk adaptations during sudden external perturbations

    Directory of Open Access Journals (Sweden)

    Jacques Abboud

    2016-11-01

    Full Text Available IntroductionWhen the spine is subjected to perturbations, neuromuscular responses such as reflex muscle contractions contribute to the overall balance control and spinal stabilization mechanisms. These responses are influenced by muscle fatigue, which has been shown to trigger changes in muscle recruitment patterns. Neuromuscular adaptations, e.g. attenuation of reflex activation and/or postural oscillations following repeated unexpected external perturbations, have also been described. However, the characterization of these adaptations still remains unclear. Using high-density electromyography (EMG may help understand how the nervous system chooses to deal with an unknown perturbation in different physiological and/or mechanical perturbation environments. AimTo characterize trunk neuromuscular adaptations following repeated sudden external perturbations after a back muscle fatigue task using high-density EMG.MethodsTwenty-five healthy participants experienced a series of 15 sudden external perturbations before and after back muscle fatigue. Erector spinae muscle activity was recorded using high-density EMG. Trunk kinematics during perturbation trials were collected using a 3-D motion analysis system. A two-way repeated measure ANOVA was conducted to assess 1 the adaptation effect across trials, 2 the fatigue effect, and 3 the interaction effect (fatigue x adaptation for the baseline activity, the reflex latency, the reflex peak and trunk kinematic variables (flexion angle, velocity and time to peak velocity. Muscle activity spatial distribution before and following the fatigue task was also compared using t-tests for dependent samples. ResultsAn attenuation of muscle reflex peak was observed across perturbation trials before the fatigue task, but not after. The spatial distribution of muscle activity was significantly higher before the fatigue task compared to post-fatigue trials. Baseline activity showed a trend to higher values after muscle

  10. Effects of exercise improves muscle strength and fat mass in patients with high fracture risk: A randomized control trial

    Directory of Open Access Journals (Sweden)

    Ding-Cheng Chan

    2018-07-01

    Full Text Available Background: The deterioration of the musculoskeletal system imposes significant impact on physical activity. Exercise is an important strategy which minimizes these changes. It is not clear which type of exercise provides better improvement on low physical performance, low muscle mass and low strength of sarcopenia. We aim to develop an integrated care (IC model and compare its relative efficacy in limb fat free mass, muscle strength, and physical performance with low extremities exercise (LEE in community dwelling older adults with high risk of fractures (Fracture Risk Assessment Tool (FRAX® ≧3% for hip fracture, ≧20% for major osteoporotic fracture or 1-min osteoporosis risk test (≧1 point or fall (≧2 falls in previous year. Methods: Patients were assigned randomized to participate in either IC or LEE group (n = 55 each for 3 months. All participants received education including home-based exercise. The IC group consisted of different modalities of exercise while the LEE group performed machine-based low extremities exercise. Fat free mass, muscle strength, and physical performance were measured at their baseline and 3-months follow-up. Results: Mean age was 73.8 ± 7 years with 69.1% women. Entire cohort demonstrated significant increment in fat free mass, muscle strength (4 indicators and physical performance (3 indicators. However, between group differences were not significant. Conclusion: With regular supervise exercise; both groups are equally effective in decreasing fat mass and increasing physical performance, muscle mass and strength. However, the IC group required fewer resources and thus more financially feasible in a community setting. Keywords: Bone mineral density, Gender differences, Integrated care, Low extremities exercise, Muscle strength

  11. Molecules in motion: influences of diffusion on metabolic structure and function in skeletal muscle.

    Science.gov (United States)

    Kinsey, Stephen T; Locke, Bruce R; Dillaman, Richard M

    2011-01-15

    Metabolic processes are often represented as a group of metabolites that interact through enzymatic reactions, thus forming a network of linked biochemical pathways. Implicit in this view is that diffusion of metabolites to and from enzymes is very fast compared with reaction rates, and metabolic fluxes are therefore almost exclusively dictated by catalytic properties. However, diffusion may exert greater control over the rates of reactions through: (1) an increase in reaction rates; (2) an increase in diffusion distances; or (3) a decrease in the relevant diffusion coefficients. It is therefore not surprising that skeletal muscle fibers have long been the focus of reaction-diffusion analyses because they have high and variable rates of ATP turnover, long diffusion distances, and hindered metabolite diffusion due to an abundance of intracellular barriers. Examination of the diversity of skeletal muscle fiber designs found in animals provides insights into the role that diffusion plays in governing both rates of metabolic fluxes and cellular organization. Experimental measurements of metabolic fluxes, diffusion distances and diffusion coefficients, coupled with reaction-diffusion mathematical models in a range of muscle types has started to reveal some general principles guiding muscle structure and metabolic function. Foremost among these is that metabolic processes in muscles do, in fact, appear to be largely reaction controlled and are not greatly limited by diffusion. However, the influence of diffusion is apparent in patterns of fiber growth and metabolic organization that appear to result from selective pressure to maintain reaction control of metabolism in muscle.

  12. Influence of experimental occlusal discrepancy on masticatory muscle activity during clenching.

    Science.gov (United States)

    Baba, K; Ai, M; Mizutani, H; Enosawa, S

    1996-01-01

    The influence of the experimental occlusal discrepancy on masticatory muscle activity was investigated on 12 subjects. Specially designed occlusal interferences were fabricated and various occlusal states were simulated with their aid. Subjects were asked to carry out eccentric clenching efforts and electromyographic activity of the masseter plus the anterior and posterior temporal muscles was measured. When compared with clenching on the unaltered natural dentition, clenching on the experimental interferences resulted in distinct patterns in the jaw elevator muscles, and the most characteristic change was observed when clenching effort was exerted on the experimental non-working side interference. Electromyographic activity in the anterior and posterior temporal muscles was decreased on the working side and increased on the non-working side and originally unilateral activity pattern with clear dominance on the working side was altered to a bilateral pattern, while that of the masseter muscles remained uninfluenced. Resultant bilateral activity in the anterior and posterior temporal muscles is thought to cause a superior movement of the working side condyle and an inferior movement of the non-working side condyle.

  13. Polymorphisms of muscle genes are associated with bone mass and incident osteoporotic fractures in Caucasians

    DEFF Research Database (Denmark)

    Harsløf, Torben; Frost, M; Nielsen, T L

    2013-01-01

    The interaction between muscle and bone is complex. The aim of this study was to investigate if variations in the muscle genes myostatin (MSTN), its receptor (ACVR2B), myogenin (MYOG), and myoD1 (MYOD1) were associated with fracture risk, bone mineral density (BMD), bone mineral content (BMC......), and lean body mass. We analyzed two independent cohorts: the Danish Osteoporosis Prevention Study (DOPS), comprising 2,016 perimenopausal women treated with hormone therapy or not and followed for 10 years, and the Odense Androgen Study (OAS), a cross-sectional, population-based study on 783 men aged 20......-29 years. Nine tag SNPs in the four genes were investigated. In the DOPS, individuals homozygous for the variant allele of the MSTN SNP rs7570532 had an increased risk of any osteoporotic fracture, with an HR of 1.82 (95 % CI 1.15-2.90, p = 0.01), and of nonvertebral osteoporotic fracture, with an HR of 2...

  14. Circulating levels of TNF-alpha and IL-6-relation to truncal fat mass and muscle mass in healthy elderly individuals and in patients with type-2 diabetes

    DEFF Research Database (Denmark)

    Pedersen, Maria; Bruunsgaard, Helle; Weis, Nina

    2003-01-01

    The purpose of the current study was to test the hypothesis that an altered fat distribution in elderly healthy subjects and in patients with type-2 diabetes contributes to high circulating levels of interleukin (IL)-6 and tumor necrotic factor (TNF)-alpha, which secondly is related to lower muscle...... mass. Twenty young controls, (20-35 yr), 20 healthy elderly subjects (65-80 yr) and 16 elderly patients with type 2 diabetes (65-80 yr) were included in a cross sectional study. Plasma levels of TNF-alpha and IL-6 were measured after an overnight fast. Dual-energy X-ray absorptiometry and total body...... potassium counting measured truncal fat, appendicular skeletal muscle mass (ASM) and body cell mass (BCM), respectively. TNF-alpha, IL-6 and the relative truncal fat mass were higher in elderly compared with young controls. ASM was lower in diabetic men than in young controls and BCM was lower in elderly...

  15. The influence of various risk factors on the strength of pelvic floor muscle in women

    Directory of Open Access Journals (Sweden)

    Parezanović-Ilić Katarina

    2017-01-01

    Full Text Available Background/Aim. Damage of any element of pelvic floor leads to its functional damages, reflected in the occurrence of urinary incontinence, prolapse of pelvic organs, fecal incontinence and sexual dysfunction. Basic aim of our paper was to investigate the influence of various risk factors on pelvic floor muscle strength in women. Methods. The study included 90 female patients and examined how age, job, body weight and height, number of deliveries, sports activities, incontinence occurrence, previous prolapse-caused gynecological surgeries, other gynecological surgeries and other conservatively treated gynecological diseases influence the value of pelvic floor muscle strength. Pelvic floor muscle strength was measured using vaginal dynamometer. Results. Univariate regression analysis showed that parameters such as age, demanding job, body height, number of deliveries, sports activities, prolapse-caused gynecological surgeries, other gynecological surgeries and other gynecological diseases were in positive correlation with the values of pelvic floor muscle strength. In multivariate regression model, incontinence and gynecological operation of prolapse were singled out as independent risk factors. Conclusion. If risk factors that cause damage to pelvic floor muscle are known, it is possible to prevent the damages and improve the quality of women's life.

  16. Leg strength and lean mass symmetry influences kicking performance in Australian football.

    Science.gov (United States)

    Hart, Nicolas H; Nimphius, Sophia; Spiteri, Tania; Newton, Robert U

    2014-01-01

    Differential loading patterns during game-based participation may produce or exacerbate strength imbalances between the lower limbs. It is currently unknown whether such imbalances are functionally beneficial or detrimental to performance. This study assessed the influence of lower limb strength and lean mass symmetry on kicking accuracy in Australian Football. Thirty-one Australian footballers were required to perform a kicking assessment, producing ten drop punt kicks over twenty metres to a player target. Athletes were subsequently separated into accurate (n = 15) and inaccurate (n = 16) groups, with lower-body lean mass assessed using whole body DXA scans, and lower-body strength assessed using an isometric protocol. Accurate kickers demonstrated significantly higher relative lean mass (~8% to 16%; p = 0. 001 to 0.004) and significantly lower relative fat mass (~21% to 40%; p = 0.001 to 0.024) than inaccurate kickers. Accurate kickers did not contain any significant difference in lean mass or unilateral strength between lower limbs. Inaccurate kickers displayed significant asymmetry in lean mass (~3%; p ≤ 0.003), producing significant imbalances in strength (~8%; p ≤ 0.002) highlighting a deficiency in their support leg. Greater relative strength and improved lower limb symmetry in strength and muscularity could increase the capacity of an athlete to be technically proficient in favour of greater accuracy. Key PointsStrength deficits in the support leg may lead to inaccurate kicking outcomes.An asymmetry of 3% in lean mass generated an 8% imbalance in leg strength.Greater levels of relative lower-body strength and muscle mass are associated with improved kicking accuracy performance.

  17. Testosterone therapy increased muscle mass and lipid oxidation in aging men

    DEFF Research Database (Denmark)

    Frederiksen, Louise; Højlund, Kurt; Hougaard, David M

    2011-01-01

    The indication for testosterone therapy in aging hypogonadal men without hypothalamic, pituitary, or testicular disease remains to be elucidated. The aim of this study was to investigate the effect of testosterone therapy on insulin sensitivity, substrate metabolism, body composition, and lipids...... lipid oxidation (b = 5.65 mg/min/m(2), p = 0.045) increased and basal glucose oxidation (b = -9.71 mg/min/m(2), p = 0.046) decreased in response to testosterone therapy even when corrected for changes in LBM. No significant changes in insulin-stimulated Rd was observed (b = -0.01mg/min/m(2), p = 0.......92). Testosterone therapy increased muscle mass and lipid oxidation in aging men with low normal bioavailable testosterone levels; however, our data did not support an effect of testosterone on whole-body insulin sensitivity using the euglycemic hyperinsulinemic clamp technique....

  18. Influence of tip mass on dynamic behavior of cracked cantilever pipe conveying fluid with moving mass

    International Nuclear Information System (INIS)

    Yoon, Han Ik; Son, In Soo

    2005-01-01

    In this paper, we studied about the effect of the open crack and a tip mass on the dynamic behavior of a cantilever pipe conveying fluid with a moving mass. The equation of motion is derived by using Lagrange's equation and analyzed by numerical method. The cantilever pipe is modelled by the Euler-Bernoulli beam theory. The crack section is represented by a local flexibility matrix connecting two undamaged pipe segments. The influences of the crack, the moving mass, the tip mass and its moment of inertia, the velocity of fluid, and the coupling of these factors on the vibration mode, the frequency, and the tip-displacement of the cantilever pipe are analytically clarified

  19. Muscle quality, aerobic fitness and fat mass predict lower-extremity physical function in community-dwelling older adults.

    Science.gov (United States)

    Misic, Mark M; Rosengren, Karl S; Woods, Jeffrey A; Evans, Ellen M

    2007-01-01

    Muscle mass, strength and fitness play a role in lower-extremity physical function (LEPF) in older adults; however, the relationships remain inadequately characterized. This study aimed to examine the relationships between leg mineral free lean mass (MFLM(LEG)), leg muscle quality (leg strength normalized for MFLM(LEG)), adiposity, aerobic fitness and LEPF in community-dwelling healthy elderly subjects. Fifty-five older adults (69.3 +/- 5.5 years, 36 females, 19 males) were assessed for leg strength using an isokinetic dynamometer, body composition by dual energy X-ray absorptiometry and aerobic fitness via a treadmill maximal oxygen consumption test. LEPF was assessed using computerized dynamic posturography and stair ascent/descent, a timed up-and-go task and a 7-meter walk with and without an obstacle. Muscle strength, muscle quality and aerobic fitness were similarly correlated with static LEPF tests (r range 0.27-0.40, p < 0.05); however, the strength of the independent predictors was not robust with explained variance ranging from 9 to 16%. Muscle quality was the strongest correlate of all dynamic LEPF tests (r range 0.54-0.65, p < 0.001). Using stepwise linear regression analysis, muscle quality was the strongest independent predictor of dynamic physical function explaining 29-42% of the variance (p < 0.001), whereas aerobic fitness or body fat mass explained 5-6% of the variance (p < 0.05) depending on performance measure. Muscle quality is the most important predictor, and aerobic fitness and fat mass are secondary predictors of LEPF in community-dwelling older adults. These findings support the importance of exercise, especially strength training, for optimal body composition, and maintenance of strength and physical function in older adults.

  20. Mass media influence spreading in social networks with community structure

    Science.gov (United States)

    Candia, Julián; Mazzitello, Karina I.

    2008-07-01

    We study an extension of Axelrod's model for social influence, in which cultural drift is represented as random perturbations, while mass media are introduced by means of an external field. In this scenario, we investigate how the modular structure of social networks affects the propagation of mass media messages across a society. The community structure of social networks is represented by coupled random networks, in which two random graphs are connected by intercommunity links. Considering inhomogeneous mass media fields, we study the conditions for successful message spreading and find a novel phase diagram in the multidimensional parameter space. These findings show that social modularity effects are of paramount importance for designing successful, cost-effective advertising campaigns.

  1. The role of mTOR signaling in the regulation of protein synthesis and muscle mass during immobilization in mice

    Science.gov (United States)

    You, Jae-Sung; Anderson, Garrett B.; Dooley, Matthew S.; Hornberger, Troy A.

    2015-01-01

    ABSTRACT The maintenance of skeletal muscle mass contributes substantially to health and to issues associated with the quality of life. It has been well recognized that skeletal muscle mass is regulated by mechanically induced changes in protein synthesis, and that signaling by mTOR is necessary for an increase in protein synthesis and the hypertrophy that occurs in response to increased mechanical loading. However, the role of mTOR signaling in the regulation of protein synthesis and muscle mass during decreased mechanical loading remains largely undefined. In order to define the role of mTOR signaling, we employed a mouse model of hindlimb immobilization along with pharmacological, mechanical and genetic means to modulate mTOR signaling. The results first showed that immobilization induced a decrease in the global rates of protein synthesis and muscle mass. Interestingly, immobilization also induced an increase in mTOR signaling, eIF4F complex formation and cap-dependent translation. Blocking mTOR signaling during immobilization with rapamycin not only impaired the increase in eIF4F complex formation, but also augmented the decreases in global protein synthesis and muscle mass. On the other hand, stimulating immobilized muscles with isometric contractions enhanced mTOR signaling and rescued the immobilization-induced decrease in global protein synthesis through a rapamycin-sensitive mechanism that was independent of ribosome biogenesis. Unexpectedly, the effects of isometric contractions were also independent of eIF4F complex formation. Similar to isometric contractions, overexpression of Rheb in immobilized muscles enhanced mTOR signaling, cap-dependent translation and global protein synthesis, and prevented the reduction in fiber size. Therefore, we conclude that the activation of mTOR signaling is both necessary and sufficient to alleviate the decreases in protein synthesis and muscle mass that occur during immobilization. Furthermore, these results indicate

  2. The Role of Muscle Mass, Muscle Quality, and Body Composition in Risk for the Metabolic Syndrome and Functional Decline in Older Adults: Topical Collection on Nutrition, Obesity, and Diabetes

    NARCIS (Netherlands)

    R.T. Mankowski (Robert T.); S.D. Anton (Stephen D.); M. Aubertin-Leheudre (Mylene)

    2015-01-01

    textabstractAbstract Age-related body composition changes include both loss of muscle mass (sarcopenia) and increase in fat mass, which jointly contribute to a decline in metabolic functions. Muscle quality is positively related to functional capacity and a lower risk for the development of the

  3. Contribution of Heritability and Epigenetic Factors to Skeletal Muscle Mass Variation in United Kingdom Twins.

    Science.gov (United States)

    Livshits, Gregory; Gao, Fei; Malkin, Ida; Needhamsen, Maria; Xia, Yudong; Yuan, Wei; Bell, Christopher G; Ward, Kirsten; Liu, Yuan; Wang, Jun; Bell, Jordana T; Spector, Tim D

    2016-06-01

    Skeletal muscle mass (SMM) is one of the major components of human body composition, with deviations from normal values often leading to sarcopenia. Our major aim was to conduct a genome-wide DNA methylation study in an attempt to identify potential genomic regions associated with SMM. This was a mixed cross-sectional and longitudinal study. Community-based study. A total of 1550 middle-aged United Kingdom twins (monozygotic [MZ] and dizygotic [DZ]), 297 of which were repeatedly measured participated in the study. Appendicular lean mass assessed using dual-energy X-ray absorptiometry technology, and methylated DNA immunoprecipitation sequencing DNA methylation profiling genome-wide were obtained from each individual. Heritability estimate of SMM, with simultaneous adjustment for covariates obtained using variance decomposition analysis, was h(2) = 0.809 ± 0.050. After quality control and analysis of longitudinal stability, the DNA methylation data comprised of 723 029 genomic sites, with positive correlations between repeated measurements (Rrepeated = 0.114-0.905). Correlations between MZ and DZ twins were 0.51 and 0.38 at a genome-wide average, respectively, and clearly increased with Rrepeated. Testing for DNA methylation association with SMM in 50 discordant MZ twins revealed 36 081 nominally significant results, of which the top-ranked 134 signals (P 0.40) were subjected to replication in the sample of 1196 individuals. Seven SMM methylation association signals replicated at a false discovery rate less than 0.1, and these were located in or near genes DNAH12, CAND1, CYP4F29P, and ZFP64, which have previously been highlighted in muscle-related studies. Adjusting for age, smoking, and blood cell heterogeneity did not alter significance of these associations. This epigenome-wide study, testing longitudinally stable methylation sites, discovered and replicated a number of associations between DNA methylation at CpG loci and SMM. Four replicated signals were

  4. Influence of diet on the incorporation of labelled amino acids in muscles of calves

    International Nuclear Information System (INIS)

    Kumar, P.; Hansen, R.J.; Black, A.L.

    1974-01-01

    Experiments were conducted to study the influence of diet on the incorporation of labelled amino acids into the semitendinosus and biceps femoris muscles of calves after 48 h administration of isotope through jugular vein. 14 C or 3 H-labelled tyrosine and 14 C or 3 H-histidine were used as tracers. The results suggest that the incorporation into myofibrillar protein fraction of both the muscles was at least two fold greater on good diets as compared to all forage ration. Similar trend was also recorded with the plasma protein fraction at both 24 and 48 h after injection. (author)

  5. Influence of diet on the incorporation of labelled amino acids in muscles of calves

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, P; Hansen, R J; Black, A L [California Univ., Davis (USA). Dept. of Physiological Sciences

    1974-12-01

    Experiments were conducted to study the influence of diet on the incorporation of labeled amino acids into the semitendinosus and biceps femoris muscles of calves after 48 h administration of isotope through jugular vein. /sup 14/C or /sup 3/H-labelled tyrosine and /sup 14/C or /sup 3/H-histidine were used as tracers. The results suggest that the incorporation into myofibrillar protein fraction of both the muscles was at least two fold greater on good diets as compared to all forage ration. Similar trend was also recorded with the plasma protein fraction at both 24 and 48 h after injection.

  6. Electrically Stimulated Antagonist Muscle Contraction Increased Muscle Mass and Bone Mineral Density of One Astronaut - Initial Verification on the International Space Station.

    Science.gov (United States)

    Shiba, Naoto; Matsuse, Hiroo; Takano, Yoshio; Yoshimitsu, Kazuhiro; Omoto, Masayuki; Hashida, Ryuki; Tagawa, Yoshihiko; Inada, Tomohisa; Yamada, Shin; Ohshima, Hiroshi

    2015-01-01

    Musculoskeletal atrophy is one of the major problems of extended periods of exposure to weightlessness such as on the International Space Station (ISS). We developed the Hybrid Training System (HTS) to maintain an astronaut's musculoskeletal system using an electrically stimulated antagonist to resist the volitional contraction of the agonist instead of gravity. The present study assessed the system's orbital operation capability and utility, as well as its preventative effect on an astronaut's musculoskeletal atrophy. HTS was attached to the non-dominant arm of an astronaut staying on the ISS, and his dominant arm without HTS was established as the control (CTR). 10 sets of 10 reciprocal elbow curls were one training session, and 12 total sessions of training (3 times per week for 4 weeks) were performed. Pre and post flight ground based evaluations were performed by Biodex (muscle performance), MRI (muscle volume), and DXA (BMD, lean [muscle] mass, fat mass). Pre and post training inflight evaluations were performed by a hand held dynamometer (muscle force) and a measuring tape (upper arm circumference). The experiment was completed on schedule, and HTS functioned well without problems. Isokinetic elbow extension torque (Nm) changed -19.4% in HTS, and -21.7% in CTR. Isokinetic elbow flexion torque changed -23.7% in HTS, and there was no change in CTR. Total Work (Joule) of elbow extension changed -8.3% in HTS, and +0.3% in CTR. For elbow flexion it changed -23.3% in HTS and -32.6% in CTR. Average Power (Watts) of elbow extension changed +22.1% in HTS and -8.0% in CTR. For elbow flexion it changed -6.5% in HTS and -4.8% in CTR. Triceps muscle volume according to MRI changed +11.7% and that of biceps was +2.1% using HTS, however -0.1% and -0.4% respectively for CTR. BMD changed +4.6% in the HTS arm and -1.2% for CTR. Lean (muscle) mass of the arm changed only +10.6% in HTS. Fat mass changed -12.6% in HTS and -6.4% in CTR. These results showed the orbital operation

  7. Electrically Stimulated Antagonist Muscle Contraction Increased Muscle Mass and Bone Mineral Density of One Astronaut - Initial Verification on the International Space Station.

    Directory of Open Access Journals (Sweden)

    Naoto Shiba

    Full Text Available Musculoskeletal atrophy is one of the major problems of extended periods of exposure to weightlessness such as on the International Space Station (ISS. We developed the Hybrid Training System (HTS to maintain an astronaut's musculoskeletal system using an electrically stimulated antagonist to resist the volitional contraction of the agonist instead of gravity. The present study assessed the system's orbital operation capability and utility, as well as its preventative effect on an astronaut's musculoskeletal atrophy.HTS was attached to the non-dominant arm of an astronaut staying on the ISS, and his dominant arm without HTS was established as the control (CTR. 10 sets of 10 reciprocal elbow curls were one training session, and 12 total sessions of training (3 times per week for 4 weeks were performed. Pre and post flight ground based evaluations were performed by Biodex (muscle performance, MRI (muscle volume, and DXA (BMD, lean [muscle] mass, fat mass. Pre and post training inflight evaluations were performed by a hand held dynamometer (muscle force and a measuring tape (upper arm circumference.The experiment was completed on schedule, and HTS functioned well without problems. Isokinetic elbow extension torque (Nm changed -19.4% in HTS, and -21.7% in CTR. Isokinetic elbow flexion torque changed -23.7% in HTS, and there was no change in CTR. Total Work (Joule of elbow extension changed -8.3% in HTS, and +0.3% in CTR. For elbow flexion it changed -23.3% in HTS and -32.6% in CTR. Average Power (Watts of elbow extension changed +22.1% in HTS and -8.0% in CTR. For elbow flexion it changed -6.5% in HTS and -4.8% in CTR. Triceps muscle volume according to MRI changed +11.7% and that of biceps was +2.1% using HTS, however -0.1% and -0.4% respectively for CTR. BMD changed +4.6% in the HTS arm and -1.2% for CTR. Lean (muscle mass of the arm changed only +10.6% in HTS. Fat mass changed -12.6% in HTS and -6.4% in CTR.These results showed the orbital

  8. INFLUENCE OF STRENGTH TRAINING PROGRAM ON ISOMETRIC MUSCLE STRENGTH IN YOUNG ATHLETES

    Directory of Open Access Journals (Sweden)

    Dragan Radovanovic

    2007-10-01

    Full Text Available Strength training, or resistance training, is a form of physical conditioning used to increase the ability to resist force. Since muscular strength is required for success in many sports, it is logical to assume that stronger and more powerful young athletes will achieve better results. The aim of the study was to examine the effects of strength training on young athletes. An eight-week strength training program for developing muscle strength was performed in this study. Training protocol was designed specifically for young adolescent’s athletes. The program consisted of exercises for lower and upper body, abdominal and lower back muscles. The programs did not involve the maximal (1-3 repetitions maximum and other very hard intensity exercises that may had negative effect on young athletes. The results showed that strength training program had positive effects on maximal isometric muscle force (Fmax and motor skill. The increase presents the combined influence of strength training and growth.

  9. Deficiency of heat shock transcription factor 1 suppresses heat stress-associated increase in slow soleus muscle mass of mice.

    Science.gov (United States)

    Ohno, Y; Egawa, T; Yokoyama, S; Nakai, A; Sugiura, T; Ohira, Y; Yoshioka, T; Goto, K

    2015-12-01

    Effects of heat shock transcription factor 1 (HSF1) deficiency on heat stress-associated increase in slow soleus muscle mass of mice were investigated. Both HSF1-null and wild-type mice were randomly assigned to control and heat-stressed groups. Mice in heat-stressed group were exposed to heat stress (41 °C for 60 min) in an incubator without anaesthesia. Significant increase in wet and dry weights, and protein content of soleus muscle in wild-type mice was observed seven days after the application of the heat stress. However, heat stress had no impact on soleus muscle mass in HSF1-null mice. Neither type of mice exhibited much effect of heat stress on HSF mRNA expression (HSF1, HSF2 and HSF4). On the other hand, heat stress upregulated heat shock proteins (HSPs) at the mRNA (HSP72) and protein (HSP72 and HSP110) levels in wild-type mice, but not in HSF1-null mice. The population of Pax7-positive nuclei relative to total myonuclei of soleus muscle in wild-type mice was significantly increased by heat stress, but not in HSF1-null mice. Furthermore, the absence of HSF1 gene suppressed heat stress-associated phosphorylation of Akt and p70 S6 kinase (p-p70S6K) in soleus muscle. Heat stress-associated increase in skeletal muscle mass may be induced by HSF1 and/or HSF1-mediated stress response that activates muscle satellite cells and Akt/p70S6K signalling pathway. © 2015 Scandinavian Physiological Society. Published by John Wiley & Sons Ltd.

  10. Effects of exercise improves muscle strength and fat mass in patients with high fracture risk: A randomized control trial.

    Science.gov (United States)

    Chan, Ding-Cheng; Chang, Chirn-Bin; Han, Der-Sheng; Hong, Cian-Hui; Hwang, Jawl-Shan; Tsai, Keh-Sung; Yang, Rong-Sen

    2017-10-26

    The deterioration of the musculoskeletal system imposes significant impact on physical activity. Exercise is an important strategy which minimizes these changes. It is not clear which type of exercise provides better improvement on low physical performance, low muscle mass and low strength of sarcopenia. We aim to develop an integrated care (IC) model and compare its relative efficacy in limb fat free mass, muscle strength, and physical performance with low extremities exercise (LEE) in community dwelling older adults with high risk of fractures (Fracture Risk Assessment Tool (FRAX ® )) ≧3% for hip fracture, ≧20% for major osteoporotic fracture or 1-min osteoporosis risk test (≧1 point) or fall (≧2 falls in previous year). Patients were assigned randomized to participate in either IC or LEE group (n = 55 each) for 3 months. All participants received education including home-based exercise. The IC group consisted of different modalities of exercise while the LEE group performed machine-based low extremities exercise. Fat free mass, muscle strength, and physical performance were measured at their baseline and 3-months follow-up. Mean age was 73.8 ± 7 years with 69.1% women. Entire cohort demonstrated significant increment in fat free mass, muscle strength (4 indicators) and physical performance (3 indicators). However, between group differences were not significant. With regular supervise exercise; both groups are equally effective in decreasing fat mass and increasing physical performance, muscle mass and strength. However, the IC group required fewer resources and thus more financially feasible in a community setting. Copyright © 2017. Published by Elsevier B.V.

  11. Cross-training in birds: cold and exercise training produce similar changes in maximal metabolic output, muscle masses and myostatin expression in house sparrows (Passer domesticus)

    Science.gov (United States)

    Zhang, Yufeng; Eyster, Kathleen; Liu, Jin-Song; Swanson, David L.

    2015-01-01

    ABSTRACT Maximal metabolic outputs for exercise and thermogenesis in birds presumably influence fitness through effects on flight and shivering performance. Because both summit (Msum, maximum thermoregulatory metabolic rate) and maximum (MMR, maximum exercise metabolic rate) metabolic rates are functions of skeletal muscle activity, correlations between these measurements and their mechanistic underpinnings might occur. To examine whether such correlations occur, we measured the effects of experimental cold and exercise training protocols for 3 weeks on body (Mb) and muscle (Mpec) masses, basal metabolic rate (BMR), Msum, MMR, pectoralis mRNA and protein expression for myostatin, and mRNA expression of TLL-1 and TLL-2 (metalloproteinase activators of myostatin) in house sparrows (Passer domesticus). Both training protocols increased Msum, MMR, Mb and Mpec, but BMR increased with cold training and decreased with exercise training. No significant differences occurred for pectoralis myostatin mRNA expression, but cold and exercise increased the expression of TLL-1 and TLL-2. Pectoralis myostatin protein levels were generally reduced for both training groups. These data clearly demonstrate cross-training effects of cold and exercise in birds, and are consistent with a role for myostatin in increasing pectoralis muscle mass and driving organismal increases in metabolic capacities. PMID:25987736

  12. Cross-training in birds: cold and exercise training produce similar changes in maximal metabolic output, muscle masses and myostatin expression in house sparrows (Passer domesticus).

    Science.gov (United States)

    Zhang, Yufeng; Eyster, Kathleen; Liu, Jin-Song; Swanson, David L

    2015-07-01

    Maximal metabolic outputs for exercise and thermogenesis in birds presumably influence fitness through effects on flight and shivering performance. Because both summit (Msum, maximum thermoregulatory metabolic rate) and maximum (MMR, maximum exercise metabolic rate) metabolic rates are functions of skeletal muscle activity, correlations between these measurements and their mechanistic underpinnings might occur. To examine whether such correlations occur, we measured the effects of experimental cold and exercise training protocols for 3 weeks on body (Mb) and muscle (Mpec) masses, basal metabolic rate (BMR), Msum, MMR, pectoralis mRNA and protein expression for myostatin, and mRNA expression of TLL-1 and TLL-2 (metalloproteinase activators of myostatin) in house sparrows (Passer domesticus). Both training protocols increased Msum, MMR, Mb and Mpec, but BMR increased with cold training and decreased with exercise training. No significant differences occurred for pectoralis myostatin mRNA expression, but cold and exercise increased the expression of TLL-1 and TLL-2. Pectoralis myostatin protein levels were generally reduced for both training groups. These data clearly demonstrate cross-training effects of cold and exercise in birds, and are consistent with a role for myostatin in increasing pectoralis muscle mass and driving organismal increases in metabolic capacities. © 2015. Published by The Company of Biologists Ltd.

  13. Low vitamin D status is associated with reduced muscle mass and impaired physical performance in frail elderly people

    NARCIS (Netherlands)

    Tieland, C.A.B.; Brouwer, E.M.; Nienaber-Rousseau, C.; Loon, van L.J.C.; Groot, de C.P.G.M.

    2013-01-01

    Background/Objectives: Serum 25-hydroxyvitamin D (25(OH)D) status has been associated with muscle mass, strength and physical performance in healthy elderly people. Yet, in pre-frail and frail elderly people this association has not been studied. The objective of this study was to explore the

  14. The impact of dietary protein or amino acid supplementation on muscle mass and strength in elderly people

    NARCIS (Netherlands)

    Tieland, M.; Franssen, R.; Dullemeijer, C.; Dronkelaar, van C.; Kim, H.K.; Ispoglou, T.; Zhu, K.; Prince, R.L.; Loon, van L.J.C.; Groot, de Lisette C.P.G.M.

    2017-01-01

    Objectives: Increasing protein or amino acid intake has been promoted as a promising strategy to increase muscle mass and strength in elderly people, however, long-term intervention studies show inconsistent findings. Therefore, we aim to determine the impact of protein or amino acid

  15. Low skeletal muscle mass is associated with increased hospital expenditure in patients undergoing cancer surgery of the alimentary tract

    NARCIS (Netherlands)

    J.L.A. van Vugt (Jeroen); S. Büttner (Stefan); S. Levolger (S.); R.R.J. Coebergh van den Braak (Robert); M. Suker (Mustafa); M.P. Gaspersz (Marcia); R.W.F. de Bruin (Ron); C. Verhoef (Kees); Van Eijck, C.H.C. (Casper H. C.); Bossche, N. (Niek); B. Groot Koerkamp (Bas); J.N.M. IJzermans (Jan)

    2017-01-01

    textabstractBackground: Low skeletal muscle mass is associated with poor postoperative outcomes in cancer patients. Furthermore, it is associated with increased healthcare costs in the United States. We investigated its effect on hospital expenditure in a Western-European healthcare system, with

  16. Basic Training of Student’s Outdoor Club Increases Muscle Mass after Five Weeks of Exercise in Males

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    Novie Salsabila

    2015-03-01

    Full Text Available Background: Aerobic and anaerobic exercises, may lead to increase muscle mass. The aim of this study was to determine the change in muscle mass during basic training of students’ outdoor club. Methods: This was an observational analytic study to college students who joined basic training of students’ outdoor club for 19 weeks. Subjects consisted of 17 male and 15 female students, measured five times consecutively by using Body Fat/Hydration monitor scale, with Bioelectrical Impedance Analysis principle. Data collection was performed five times, from February to July 2012 in Bandung. Statistical analysis was processed using Analysis of Variance (ANOVA. Results: The result in males showed the mean 43.35±3.15 on the initial measurement. The muscle mass further increased significantly after five, ten, fifteen, and nineteen weeks of exercise (43.73±3.18 (p0.05; 38.08±1.67 (p>0.05 ; 38.23±1.52 (p>0.05 ; 38.61±1.52 (p<0.05 vs 37.77±2.00 respectively. Conclusion: Basic training of student’s outdoor club increases muscle mass significantly after five weeks of exercise in males, but not in females

  17. Measurement of Muscle Protein Fractional Synthetic Rate by Capillary Gas Chromatography/Combustion Isotope Ratio Mass Spectrometry

    Science.gov (United States)

    Yarasheski, Kevin E.; Smith, Kenneth; Rennie, Michael J.; Bier, Dennis M.

    2014-01-01

    The measurement of skeletal muscle protein fractional synthetic rate using an infusion of (1-13C)leucine and measuring the isotopic abundance of the tracer in skeletal muscle protein by preparative gas chromatography (GC)/ninhydrin isotope ratio mass spectrometry (IRMS) is laborious and subject to errors owing to contamination by 12C. The purpose of this study was to compare muscle (13C)leucine enrichment measured with the conventional preparative GC/ninhydrin IRMS approach to a new, continuous-flow technique using capillary GC/combustion IRMS. Quadriceps muscles were removed from four Sprague–Dawley rats after each was infused at a different rate with (1-13C)leucine for 6–8 h. Muscle leucine enrichment (at.% excess) measured by both methods differed by less than 4%, except at low (13C)leucine enrichments (IRMS was used to assess muscle (13C)leucine enrichment and fractional muscle protein synthesis rate in ten normal young men and women infused with (1,2-13C2)leucine for 12–14 h. This approach reduced the variability of the isotope abundance measure and gave estimates of muscle protein synthesis rate (0.050 ± 0.011% h−1 (mean ± SEM); range = 0.023–0.147% h−1) that agree with published values determined using the standard analytical approach. The measurement of (13C)leucine enrichment from skeletal muscle protein by capillary GC/combustion IRMS provides a simple, acceptable and practical alternative to preparative GC/ninhydrin IRMS. PMID:1420371

  18. Reference Centile Curves for Body Fat Percentage, Fat-free Mass, Muscle Mass and Bone Mass Measured by Bioelectrical Impedance in Asian Indian Children and Adolescents.

    Science.gov (United States)

    Chiplonkar, Shashi; Kajale, Neha; Ekbote, Veena; Mandlik, Rubina; Parthasarathy, Lavanya; Borade, Ashwin; Patel, Pinal; Patel, Prerna; Khadilkar, Vaman; Khadilkar, Anuradha

    2017-12-15

    To create gender-specific percentile curves for percent body fat (%BF) by Bio electrical Impedance Analysis (BIA) for screening adiposity and risk of hypertension in Indian children and generate reference curves for percent fat-free mass (%FFM), muscle mass (%LM) and bone mineral content (BMC) by using bioelectrical impedance. Secondary analysis of data from previous multicenter cross-sectional studies. Private schools from five regions of India. A random sample of 3850 healthy school children (2067 boys) (5-17 yr) from private schools in five major Indian cities. Anthropometry, blood pressure (BP) and body composition were measured by bioelectrical impedance. Reference curves were generated by the LMS method. %BF, %FFM, %LM, BMC and BP. Median %BF increased by 6% from 5 to 13 years of age and declined (around 2%) up to 17 years in boys. In girls, %BF increased by 8% from 5 to 14 years and thereafter declined by 3%. Based upon the risk of hypertension, the new cut-offs of 75th and 85th percentile of %BF were proposed for detecting over fatness and excess fatness in children. Median %FFM was 90% at 5 yrs and decreased till 12 years, and then showed a slight increase to 84% at 17 yrs in boys. In girls, it was 86% at 5 yrs and decreased till 15 yrs, and plateaued at 71.8% at 17 yrs. Reference curves for percent body fat for Indian children would be useful to screen children for health risk in clinical set up.

  19. MALDI imaging mass spectrometry: Discrimination of pathophysiological regions in traumatized skeletal muscle by characteristic peptide signatures

    OpenAIRE

    Klein, O.; Strohschein, K.; Nebrich, G.; Oetjen, J.; Trede, D.; Thiele, H.; Alexandrov, T.; Giavalisco, P.; Duda, G.N.; Roth, P. von; Geissler, S.; Klose, J.; Winkler, T.

    2014-01-01

    Due to formation of fibrosis and the loss of contractile muscle tissue, severe muscle injuries often result in insufficient healing marked by a significant reduction of muscle force and motor activity. Our previous studies demonstrated that the local transplantation of mesenchymal stromal cells into an injured skeletal muscle of the rat improves the functional outcome of the healing process. Since, due to the lack of sufficient markers, the accurate discrimination of pathophysiological region...

  20. Changes in lower limb muscle function and muscle mass following exercise-based interventions in patients with chronic obstructive pulmonary disease: A review of the English-language literature.

    Science.gov (United States)

    De Brandt, Jana; Spruit, Martijn A; Hansen, Dominique; Franssen, Frits Me; Derave, Wim; Sillen, Maurice Jh; Burtin, Chris

    2018-05-01

    Chronic obstructive pulmonary disease (COPD) patients often experience lower limb muscle dysfunction and wasting. Exercise-based training has potential to improve muscle function and mass, but literature on this topic is extensive and heterogeneous including numerous interventions and outcome measures. This review uses a detailed systematic approach to investigate the effect of this wide range of exercise-based interventions on muscle function and mass. PUBMED and PEDro databases were searched. In all, 70 studies ( n = 2504 COPD patients) that implemented an exercise-based intervention and reported muscle strength, endurance, or mass in clinically stable COPD patients were critically appraised. Aerobic and/or resistance training, high-intensity interval training, electrical or magnetic muscle stimulation, whole-body vibration, and water-based training were investigated. Muscle strength increased in 78%, muscle endurance in 92%, and muscle mass in 88% of the cases where that specific outcome was measured. Despite large heterogeneity in exercise-based interventions and outcome measures used, most exercise-based trials showed improvements in muscle strength, endurance, and mass in COPD patients. Which intervention(s) is (are) best for which subgroup of patients remains currently unknown. Furthermore, this literature review identifies gaps in the current knowledge and generates recommendations for future research to enhance our knowledge on exercise-based interventions in COPD patients.

  1. Determining the influence of muscle operating length on muscle performance during frog swimming using a bio-robotic model

    International Nuclear Information System (INIS)

    Clemente, Christofer J; Richards, Christopher

    2012-01-01

    Frogs are capable of impressive feats of jumping and swimming. Recent work has shown that anuran hind limb muscles can operate at lengths longer than the ‘optimal length’. To address the implications of muscle operating length on muscle power output and swimming mechanics, we built a robotic frog hind limb model based upon Xenopus laevis. The model simulated the force–length and force–velocity properties of vertebrate muscle, within the skeletal environment. We tested three muscle starting lengths, representing long, optimal and short starting lengths. Increasing starting length increased maximum muscle power output by 27% from 98.1 W kg −1 when muscle begins shortening from the optimal length, to 125.1 W kg −1 when the muscle begins at longer initial lengths. Therefore, longer starting lengths generated greater hydrodynamic force for extended durations, enabling faster swimming speeds of the robotic frog. These swimming speeds increased from 0.15 m s −1 at short initial muscle lengths, to 0.39 m s −1 for the longest initial lengths. Longer starting lengths were able to increase power as the muscle's force–length curve was better synchronized with the muscle's activation profile. We further dissected the underlying components of muscle force, separating force–length versus force–velocity effects, showing a transition from force–length limitations to force–velocity limitations as starting length increased. (paper)

  2. What's So Special about FGF19-Unique Effects Reported on Skeletal Muscle Mass and Function.

    Science.gov (United States)

    Glass, David J

    2017-08-01

    In a recent study published in Nature Medicine, Benoit et al. (2017) reported unique effects of FGF19 on mouse skeletal muscle: FGF19 induced skeletal muscle hypertrophy and blocked muscle atrophy, acting via FGF receptors and ßKlotho, while a related FGF21 hormone was ineffective. Copyright © 2017 Elsevier Inc. All rights reserved.

  3. Impact of Weight Loss on Physical Function with Changes in Strength, Muscle Mass, and Muscle Fat Infiltration in Overweight to Moderately Obese Older Adults: A Randomized Clinical Trial

    Directory of Open Access Journals (Sweden)

    Adam J. Santanasto

    2011-01-01

    Full Text Available Purpose. Evaluate the effects of weight loss on muscle mass and area, muscle fat infiltration, strength, and their association with physical function. Methods. Thirty-six overweight to moderately obese, sedentary older adults were randomized into either a physical activity plus weight loss (PA+WL or physical activity plus successful aging health education (PA+SA program. Measurements included body composition by dual-energy X-ray absorptiometry, computerized tomography, knee extensor strength, and short physical performance battery (SPPB. Results. At 6 months, PA+WL lost greater thigh fat and muscle area compared to PA+SA. PA+WL lost 12.4% strength; PA+SA lost 1.0%. Muscle fat infiltration decreased significantly in PA+WL and PA+SA. Thigh fat area decreased 6-fold in comparison to lean area in PA+WL. Change in total SPPB score was strongly inversely correlated with change in fat but not with change in lean or strength. Conclusion. Weight loss resulted in additional improvements in function over exercise alone, primarily due to loss of body fat.

  4. Lower Jump Power Rather Than Muscle Mass Itself is Associated with Vertebral Fracture in Community-Dwelling Elderly Korean Women.

    Science.gov (United States)

    Lee, Eun Young; Lee, Su Jin; Kim, Kyoung Min; Seo, Da Hea; Lee, Seung Won; Choi, Han Sol; Kim, Hyeon Chang; Youm, Yoosik; Kim, Chang Oh; Rhee, Yumie

    2017-06-01

    Sarcopenia is considered to be a risk factor for osteoporotic fracture, which is a major health problem in elderly women. In this study, we aimed to investigate the association of sarcopenia, with regard to muscle mass and function, with prevalent vertebral fracture in community-dwelling elderly women. We recruited 1281 women aged 64 to 87 years from the Korean Urban Rural Elderly cohort study. Muscle mass and function were measured using bioimpedance analysis and jumping mechanography. Skeletal muscle index (SMI) and jump power were used as an indicator of muscle mass and function, respectively. Among the participants, we observed 282 (18.9%) vertebral fractures and 564 (44.0%) osteoporosis. Although age, body mass index, and prevalence of osteoporosis increased as both SMI and jump power decreased, prevalence of vertebral fracture increased only when jump power decreased. In univariate analysis, compared with the highest quartile of jump power, the lowest quartile had a significant odds ratio of 2.80 (95% CI 1.79-4.36) for vertebral fracture. This association between jump power and vertebral fracture remained significant, with an odds ratio of 3.04 (95% CI 1.77-5.23), even after adjusting for other risk factors including age, bone mineral density, previous fracture, and cognitive function. In contrast, there was no association between SMI and vertebral fracture. Based on our results, low jump power, but not SMI, is associated with vertebral fracture in community-dwelling elderly Korean women. This finding suggests that jump power may have a more important role than muscle mass itself for osteoporotic fracture.

  5. Contraction-induced increases in Na+-K+-ATPase mRNA levels in human skeletal muscle are not amplified by activation of additional muscle mass

    DEFF Research Database (Denmark)

    Nordsborg, Nikolai; Thomassen, Martin; Lundby, Carsten

    2005-01-01

    The present study tested the hypothesis that exercise with a large compared with a small active muscle mass results in a higher contraction-induced increase in Na+-K+-ATPase mRNA expression due to greater hormonal responses. Furthermore, the relative abundance of Na+-K+-ATPase subunit a1, a2, a3, a......% of the a2 expression, and no reliable detection of a3 and a4 was possible. In conclusion, activation of additional muscle mass does not result in a higher exercise-induced increase in Na+-K+-ATPase subunit-specific mRNA.......4, ß1, ß2, and ß3 mRNA in human skeletal muscle was investigated. On two occasions, eight subjects performed one-legged knee extension exercise (L) or combined one-legged knee extension and bilateral arm cranking (AL) for 5.00, 4.25, 3.50, 2.75, and 2.00 min separated by 3 min of rest. Leg exercise...

  6. Influence of chronic stress and oclusal interference on masseter muscle pain in rat.

    Science.gov (United States)

    Simonić-Kocijan, Suncana; Uhac, Ivone; Braut, Vedrana; Kovac, Zoran; Pavicić, Daniela Kovacević; Fugosić, Vesna; Urek, Miranda Muhvić

    2009-09-01

    This study aimed to investigate the individual effects of chronic stress and occlusal interference, as well as their combined influence on masseter muscle pain. Experiments were performed on 28 male Wistar rats. Animals were submitted to chronic stress procedure, exposed to occlusal interference, or exposed to both mantioned procedures. At the end of the procedure animals were submitted to orofacial formalin test, and nociceptive behavioral response was evaluated. Statisticaly significant difference of nociceptive behavioral response in chronicaly stressed rats and in the animals with occlusal interference in comparation to the control group were not obtained (p > 0.05). In contrast, nociceptive behavioral response was significantly increased in rats submitted to both of experimental procedures (p occlusal interference and chronic stress influence masseter muscle pain.

  7. Dietary fat influences the expression of contractile and metabolic genes in rat skeletal muscle.

    Directory of Open Access Journals (Sweden)

    Wataru Mizunoya

    Full Text Available Dietary fat plays a major role in obesity, lipid metabolism, and cardiovascular diseases. To determine whether the intake of different types of dietary fats affect the muscle fiber types that govern the metabolic and contractile properties of the skeletal muscle, we fed male Wistar rats with a 15% fat diet derived from different fat sources. Diets composed of soybean oil (n-6 polyunsaturated fatty acids (PUFA-rich, fish oil (n-3 PUFA-rich, or lard (low in PUFAs were administered to the rats for 4 weeks. Myosin heavy chain (MyHC isoforms were used as biomarkers to delineate the skeletal muscle fiber types. Compared with soybean oil intake, fish oil intake showed significantly lower levels of the fast-type MyHC2B and higher levels of the intermediate-type MyHC2X composition in the extensor digitorum longus (EDL muscle, which is a fast-type dominant muscle. Concomitantly, MyHC2X mRNA levels in fish oil-fed rats were significantly higher than those observed in the soybean oil-fed rats. The MyHC isoform composition in the lard-fed rats was an intermediate between that of the fish oil and soybean oil-fed rats. Mitochondrial uncoupling protein 3, pyruvate dehydrogenase kinase 4, and porin mRNA showed significantly upregulated levels in the EDL of fish oil-fed rats compared to those observed in soybean oil-fed and lard-fed rats, implying an activation of oxidative metabolism. In contrast, no changes in the composition of MyHC isoforms was observed in the soleus muscle, which is a slow-type dominant muscle. Fatty acid composition in the serum and the muscle was significantly influenced by the type of dietary fat consumed. In conclusion, dietary fat affects the expression of genes related to the contractile and metabolic properties in the fast-type dominant skeletal muscle, where the activation of oxidative metabolism is more pronounced after fish oil intake than that after soybean oil intake.

  8. MALDI imaging mass spectrometry: discrimination of pathophysiological regions in traumatized skeletal muscle by characteristic peptide signatures.

    Science.gov (United States)

    Klein, Oliver; Strohschein, Kristin; Nebrich, Grit; Oetjen, Janina; Trede, Dennis; Thiele, Herbert; Alexandrov, Theodore; Giavalisco, Patrick; Duda, Georg N; von Roth, Philipp; Geissler, Sven; Klose, Joachim; Winkler, Tobias

    2014-10-01

    Due to formation of fibrosis and the loss of contractile muscle tissue, severe muscle injuries often result in insufficient healing marked by a significant reduction of muscle force and motor activity. Our previous studies demonstrated that the local transplantation of mesenchymal stromal cells into an injured skeletal muscle of the rat improves the functional outcome of the healing process. Since, due to the lack of sufficient markers, the accurate discrimination of pathophysiological regions in injured skeletal muscle is inadequate, underlying mechanisms of the beneficial effects of mesenchymal stromal cell transplantation on primary trauma and trauma adjacent muscle area remain elusive. For discrimination of these pathophysiological regions, formalin-fixed injured skeletal muscle tissue was analyzed by MALDI imaging MS. By using two computational evaluation strategies, a supervised approach (ClinProTools) and unsupervised segmentation (SCiLS Lab), characteristic m/z species could be assigned to primary trauma and trauma adjacent muscle regions. Using "bottom-up" MS for protein identification and validation of results by immunohistochemistry, we could identify two proteins, skeletal muscle alpha actin and carbonic anhydrase III, which discriminate between the secondary damage on adjacent tissue and the primary traumatized muscle area. Our results underscore the high potential of MALDI imaging MS to describe the spatial characteristics of pathophysiological changes in muscle. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Administration of soluble activin receptor 2B increases bone and muscle mass in a mouse model of osteogenesis imperfecta

    Science.gov (United States)

    DiGirolamo, Douglas J.; Singhal, Vandana; Chang, Xiaoli; Lee, Se-Jin; Germain-Lee, Emily L.

    2015-01-01

    Osteogenesis imperfecta (OI) comprises a group of heritable connective tissue disorders generally defined by recurrent fractures, low bone mass, short stature and skeletal fragility. Beyond the skeletal complications of OI, many patients also report intolerance to physical activity, fatigue and muscle weakness. Indeed, recent studies have demonstrated that skeletal muscle is also negatively affected by OI, both directly and indirectly. Given the well-established interdependence of bone and skeletal muscle in both physiology and pathophysiology and the observations of skeletal muscle pathology in patients with OI, we investigated the therapeutic potential of simultaneous anabolic targeting of both bone and skeletal muscle using a soluble activin receptor 2B (ACVR2B) in a mouse model of type III OI (oim). Treatment of 12-week-old oim mice with ACVR2B for 4 weeks resulted in significant increases in both bone and muscle that were similar to those observed in healthy, wild-type littermates. This proof of concept study provides encouraging evidence for a holistic approach to treating the deleterious consequences of OI in the musculoskeletal system. PMID:26161291

  10. The influence of thyroarytenoid and cricothyroid muscle activation on vocal fold stiffness and eigenfrequencies

    OpenAIRE

    Yin, Jun; Zhang, Zhaoyan

    2013-01-01

    The influence of the thyroarytenoid (TA) and cricothyroid (CT) muscle activation on vocal fold stiffness and eigenfrequencies was investigated in a muscularly controlled continuum model of the vocal folds. Unlike the general understanding that vocal fold fundamental frequency was determined by vocal fold tension, this study showed that vocal fold eigenfrequencies were primarily determined by vocal fold stiffness. This study further showed that, with reference to the resting state of zero stra...

  11. Influence of Chronic Stress and Oclusal Interference on Masseter Muscle Pain in Rat

    OpenAIRE

    Simonić-Kocijan, Sunčana; Uhač, Ivone; Braut, Vedrana; Kovač, Zoran; Kovačević Pavičić, Daniela; Fugošić, Vesna; Muhvić Urek, Miranda

    2009-01-01

    This study aimed to investigate the individual effects of chronic stress and occlusal interference, as well as their combined influence on masseter muscle pain. Experiments were performed on 28 male Wistar rats. Animals were submitted to chronic stress procedure, exposed to occlusal interference, or exposed to both mantioned procedures. At the end of the procedure animals were submitted to orofacial formalin test, and nociceptive behavioral response was evaluated. Statisticaly significant dif...

  12. Quantitative analysis of veterinary drugs in bovine muscle and milk by liquid chromatography quadrupole time-of-flight mass spectrometry.

    Science.gov (United States)

    Saito-Shida, Shizuka; Sakai, Takatoshi; Nemoto, Satoru; Akiyama, Hiroshi

    2017-07-01

    A simple and reliable multiresidue method for quantitative determination of veterinary drugs in bovine muscle and milk using liquid chromatography quadrupole time-of-flight mass spectrometry (LC-QTOF-MS) was developed. Critical MS parameters such as capillary voltage, cone voltage, collision energy, desolvation gas temperature and extraction mass window were carefully optimised to obtain the best possible sensitivity. Analytical samples were prepared using extraction with acetonitrile and hexane in the presence of anhydrous sodium sulphate and acetic acid, followed by ODS cartridge clean-up. The developed method was validated for 82 veterinary drugs in bovine muscle and milk at spike levels of 0.01 and 0.1 mg kg - 1 . With the exception of cefoperazone and phenoxymethylpenicillin, all these compounds exhibited sufficient signal intensity at 0.01 μg ml -1 (equivalent to 0.01 mg kg - 1 ), indicating the high sensitivity of the developed method. For most targets, the determined accuracies were within 70-120%, with repeatability and reproducibility being below 20% at both levels. Except for sulfathiazole in bovine muscle, no interfering peaks at target compound retention times were detected in the blank extract, indicating that the developed method is highly selective. The absence of sulfathiazole in bovine muscle was confirmed by simultaneous acquisition at low and high collision energies to afford exact masses of molecular adduct and fragment ions. Satisfactory linearity was observed for all compounds, with matrix effects being negligible for most targets in bovine muscle and milk at both spike levels. Overall, the results suggest that the developed LC-QTOF-MS method is suitable for routine regulatory-purpose analysis of veterinary drugs in bovine muscle and milk.

  13. Identification of skeletal muscle mass depletion across age and BMI groups in health and disease--there is need for a unified definition.

    Science.gov (United States)

    Bosy-Westphal, A; Müller, M J

    2015-03-01

    Although reduced skeletal muscle mass is a major predictor of impaired physical function and survival, it remains inconsistently diagnosed to a lack of standardized diagnostic approaches that is reflected by the variable combination of body composition indices and cutoffs. In this review, we summarized basic determinants of a normal lean mass (age, gender, fat mass, body region) and demonstrate limitations of different lean mass parameters as indices for skeletal muscle mass. A unique definition of lean mass depletion should be based on an indirect or direct measure of skeletal muscle mass normalized for height (fat-free mass index (FFMI), appendicular or lumbal skeletal muscle index (SMI)) in combination with fat mass. Age-specific reference values for FFMI or SMI are more advantageous because defining lean mass depletion on the basis of total FFMI or appendicular SMI could be misleading in the case of advanced age due to an increased contribution of connective tissue to lean mass. Mathematical modeling of a normal lean mass based on age, gender, fat mass, ethnicity and height can be used in the absence of risk-defined cutoffs to identify skeletal muscle mass depletion. This definition can be applied to identify different clinical phenotypes like sarcopenia, sarcopenic obesity or cachexia.

  14. Low relative skeletal muscle mass (sarcopenia) in older persons is associated with functional impairment and physical disability.

    Science.gov (United States)

    Janssen, Ian; Heymsfield, Steven B; Ross, Robert

    2002-05-01

    To establish the prevalence of sarcopenia in older Americans and to test the hypothesis that sarcopenia is related to functional impairment and physical disability in older persons. Cross-sectional survey. Nationally representative cross-sectional survey using data from the Third National Health and Nutrition Examination Survey (NHANES III). Fourteen thousand eight hundred eighteen adult NHANES III participants aged 18 and older. The presence of sarcopenia and the relationship between sarcopenia and functional impairment and disability were examined in 4,504 adults aged 60 and older. Skeletal muscle mass was estimated from bioimpedance analysis measurements and expressed as skeletal muscle mass index (SMI = skeletal muscle mass/body mass x 100). Subjects were considered to have a normal SMI if their SMI was greater than -one standard deviation above the sex-specific mean for young adults (aged 18-39). Class I sarcopenia was considered present in subjects whose SMI was within -one to -two standard deviations of young adult values, and class II sarcopenia was present in subjects whose SMI was below -two standard deviations of young adult values. The prevalence of class I and class II sarcopenia increased from the third to sixth decades but remained relatively constant thereafter. The prevalence of class I (59% vs 45%) and class II (10% vs 7%) sarcopenia was greater in the older (> or = 60 years) women than in the older men (P normal SMI, respectively. Some of the associations between class II sarcopenia and functional impairment remained significant after adjustment for age, race, body mass index, health behaviors, and comorbidity. Reduced relative skeletal muscle mass in older Americans is a common occurrence that is significantly and independently associated with functional impairment and disability, particularly in older women. These observations provide strong support for the prevailing view that sarcopenia may be an important and potentially reversible cause of

  15. Predicting skeletal muscle mass from dual-energy X-ray absorptiometry in Japanese prepubertal children.

    Science.gov (United States)

    Midorikawa, T; Ohta, M; Hikihara, Y; Torii, S; Sakamoto, S

    2017-10-01

    We aimed to develop regression-based prediction equations for estimating total and regional skeletal muscle mass (SMM) from measurements of lean soft tissue mass (LSTM) using dual-energy X-ray absorptiometry (DXA) and investigate the validity of these equations. In total, 144 healthy Japanese prepubertal children aged 6-12 years were divided into 2 groups: the model development group (62 boys and 38 girls) and the validation group (26 boys and 18 girls). Contiguous MRI images with a 1-cm slice thickness were obtained from the first cervical vertebra to the ankle joints as reference data. The SMM was calculated from the summation of the digitized cross-sectional areas. Total and regional LSTM was measured using DXA. Strong significant correlations were observed between the site-matched SMM (total, arms, trunk and legs) measured by MRI and the LSTM obtained by DXA in the model development group for both boys and girls (R 2 adj =0.86-0.97, Pprediction equations were applied to the validation group, the measured total (boys 9.47±2.21 kg; girls 8.18±2.62 kg) and regional SMM were very similar to the predicted values for both boys (total SMM 9.40±2.39 kg) and girls (total SMM 8.17±2.57 kg). The results of the Bland-Altman analysis for the validation group did not indicate any bias for either boys or girls with the exception of the arm region for the girls. These results suggest that the DXA-derived prediction equations are precise and accurate for the estimation of total and regional SMM in Japanese prepubertal boys and girls.

  16. Age- and gender-dependent values of skeletal muscle mass in healthy children and adolescents.

    Science.gov (United States)

    Webber, Colin E; Barr, Ronald D

    2012-03-01

    Skeletal muscle mass (SMM) can be extracted from whole-body scans obtained by X-ray-based dual-photon absorptiometry (DXA). There is a need to establish expected age-dependent values for children and adolescents. Appendicular lean tissue mass (ALM) was extracted from whole-body DXA scans in 140 healthy children and adolescents (68 females and 72 males). Whole-body SMM was calculated from ALM using equations developed by Kim et al. (Am J Clin Nutr 84:1014-1020, 2006). Age-dependent patterns of increase in SMM were derived by fitting SMM values to equations that consisted of the sum of two logistic expressions, one accounting for SMM changes during growth and the other for SMM changes during puberty. Normal ranges were defined so that 95% of the SMM values were included. The reproducibility of SMM measurements was obtained from whole-body DXA scans repeated on three occasions in each of a separate group of 32 normal children with repositioning between scans. Normal ranges are presented as equations describing the age-dependent pattern of increase in SMM as well as population standard deviations that increased steadily with age. For 15 children below age 10, SMM reproducibility (95% CI) was 149 g (119-199 g) while for 17 children and adolescents over age 10, reproducibility was 170 g (138-223 g). DXA-based measurements of SMM in children and adolescents are reproducible and can be expressed in terms of age-dependent Z scores.

  17. Genetic and Environmental Influences on Pulmonary Function and Muscle Strength: The Chinese Twin Study of Aging

    DEFF Research Database (Denmark)

    Tian, Xiaocao; Xu, Chunsheng; Wu, Yili

    2017-01-01

    Genetic and environmental influences on predictors of decline in daily functioning, including forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC), handgrip, and five-times-sit-to-stand test (FTSST), have not been addressed in the aging Chinese population. We performed classical twin...... was moderate for FEV1, handgrip, and FTSST (55-60%) but insignificant for FVC. Only FVC showed moderate control, with shared environmental factors accounting for about 50% of the total variance. In contrast, all measures of pulmonary function and muscle strength showed modest influences from the unique...

  18. Pre-hospital dietary intake correlates with muscle mass at the time of fracture in older hip fractured patients

    Directory of Open Access Journals (Sweden)

    Riccardo eCalvani

    2014-11-01

    Full Text Available Background. Failure to meet an adequate dietary intake is involved in the pathogenesis of sarcopenia and osteoporosis, which in turn increase the risk for falls and fractures, respectively. Older people with hip fracture are often protein-malnourished at hospitalization. Whether low protein-energy intake is associated with muscle atrophy in hip fractured patients is presently unknown. This information is necessary for the development of novel strategies to manage this especially vulnerable patient population. The aim of this study was therefore to explore the relationship between dietary intake and muscle mass in older hip fractured patients.Methods. Analyses were conducted in hip fractured elderly admitted to an orthopedic and trauma surgery ward (University Hospital. Muscle mass was estimated by bioelectrical impedance analysis within 24 h from admission. Dietary information was collected via 24-h dietary recall and nutrient intakes calculated by a nutrition software.Results. Among 62 hip fractured patients (mean age 84.6±7.6 years, 84% women, the average energy intake was 929.2±170.3 Kcal/day, with higher values reported by men (1.046.8±231.4 Kcal/day relative to women (906.5±148.3 Kcal/day; p=0.01. Absolute and normalized protein intake was 50.0±13.5 g/day and 0.88±0.27 g/kg (body weight/day, respectively, with no gender differences. A positive correlation was determined between total energy intake and muscle mass (r=0.384; p=0.003. Similarly, protein and leucine consumption was positively correlated with muscle mass (r=0.367 and 0.311, respectively; p=0.005 for both.Conclusions. A low intake of calories, protein and leucine is associated with reduced muscle mass in hip fractured elderly. Given the relevance of sarcopenia as a risk factor for adverse outcomes in this patient population, our findings highlight the importance of a comprehensive dietary assessment for the detection of nutritional deficits predisposing to or aggravating

  19. Influence of Body Weight on Bone Mass, Architecture, and Turnover

    Science.gov (United States)

    Iwaniec, Urszula T.; Turner, Russell T.

    2016-01-01

    Weight-dependent loading of the skeleton plays an important role in establishing and maintaining bone mass and strength. This review focuses on mechanical signaling induced by body weight as an essential mechanism for maintaining bone health. In addition, the skeletal effects of deviation from normal weight are discussed. The magnitude of mechanical strain experienced by bone during normal activities is remarkably similar among vertebrates, regardless of size, supporting the existence of a conserved regulatory mechanism, or mechanostat, that senses mechanical strain. The mechanostat functions as an adaptive mechanism to optimize bone mass and architecture based on prevailing mechanical strain. Changes in weight, due to altered mass, weightlessness (spaceflight), and hypergravity (modeled by centrifugation), induce an adaptive skeletal response. However, the precise mechanisms governing the skeletal response are incompletely understood. Furthermore, establishing whether the adaptive response maintains the mechanical competence of the skeleton has proven difficult, necessitating development of surrogate measures of bone quality. The mechanostat is influenced by regulatory inputs to facilitate non-mechanical functions of the skeleton, such as mineral homeostasis, as well as hormones and energy/nutrient availability that support bone metabolism. While the skeleton is very capable of adapting to changes in weight, the mechanostat has limits. At the limits, extreme deviations from normal weight and body composition are associated with impaired optimization of bone strength to prevailing body size. PMID:27352896

  20. Interfacial Properties of Methylcelluloses: The Influence of Molar Mass

    Directory of Open Access Journals (Sweden)

    Pauline L. Nasatto

    2014-12-01

    Full Text Available The interfacial interactions of four methylcelluloses having the same average degree of substitution and distribution of methyl groups, but different molar masses, are studied at ambient temperature and at very low polymer concentrations. Firstly, the surface tension σ at the water/air interface is determined for the progressive addition of methylcellulose up to 100 mg/L; σ starts to decrease over 1 mg/L up to the critical aggregation concentration (CAC at 10 mg/L. The curves describing the influence of polymer concentration on σ are independent of the molar mass at equilibrium. Secondly, the adsorption of methylcellulose on silica particles is estimated from ζ-potential measurements. The data are interpreted in terms of an increase of the adsorbed layer thickness at the interface when the molar mass of methylcellulose increases. It is concluded that methylcellulose is adsorbed, forming trains and loops at the interface based on the equilibrium between surface free energy and solvent quality.

  1. The Influence of Mass Media and Interpersonal Communication on Societal and Personal Risk Judgments.

    Science.gov (United States)

    Coleman, Cynthia-Lou.

    1993-01-01

    Examines the influence of mass media, interpersonal channels, and self-efficacy on risk judgment. Confirms that mass media channels influence social-level risk judgments. Finds that personal-level risk was influenced to some degree by mass media channels and that interpersonal channels and self-efficacy account for some variance on social-level…

  2. Influence of short-term unweighing and reloading on running kinetics and muscle activity.

    Science.gov (United States)

    Sainton, Patrick; Nicol, Caroline; Cabri, Jan; Barthelemy-Montfort, Joëlle; Berton, Eric; Chavet, Pascale

    2015-05-01

    In running, body weight reduction is reported to result in decreased lower limb muscle activity with no change in the global activation pattern (Liebenberg et al. in J Sports Sci 29:207-214). Our study examined the acute effects on running mechanics and lower limb muscle activity of short-term unweighing and reloading conditions while running on a treadmill with a lower body positive pressure (LBPP) device. Eleven healthy males performed two randomized running series of 9 min at preferred speed. Each series included three successive running conditions of 3 min [at 100 % body weight (BW), 60 or 80 % BW, and 100 % BW]. Vertical ground reaction force and center of mass accelerations were analyzed together with surface EMG activity recorded from six major muscles of the left lower limb for the first and last 30 s of each running condition. Effort sensation and mean heart rate were also recorded. In both running series, the unloaded running pattern was characterized by a lower step frequency (due to increased flight time with no change in contact time), lower impact and active force peaks, and also by reduced loading rate and push-off impulse. Amplitude of muscle activity overall decreased, but pre-contact and braking phase extensor muscle activity did not change, whereas it was reduced during the subsequent push-off phase. The combined neuro-mechanical changes suggest that LBPP technology provides runners with an efficient support during the stride. The after-effects recorded after reloading highlight the fact that 3 min of unweighing may be sufficient for updating the running pattern.

  3. Skeletal muscle mass and body fat in relation to successful ageing of older adults: The multi-national MEDIS study.

    Science.gov (United States)

    Tyrovolas, Stefanos; Haro, Josep-Maria; Mariolis, Anargiros; Piscopo, Suzanne; Valacchi, Giuseppe; Bountziouka, Vassiliki; Anastasiou, Foteini; Zeimbekis, Akis; Tyrovola, Dimitra; Foscolou, Alexandra; Gotsis, Efthimios; Metallinos, George; Tur, Josep-Antoni; Matalas, Antonia; Lionis, Christos; Polychronopoulos, Evangelos; Panagiotakos, Demosthenes

    2016-01-01

    The determinants that promote successful ageing still remain unknown. The aim of the present work was to evaluate the role of skeletal muscle mass and body fat percentage (BF%), in the level of successful ageing. during 2005-2011, 2663 older (aged 65-100 years) from 21 Mediterranean islands and the rural Mani region (Peloponnesus) of Greece were voluntarily enrolled in the study. Appendicular skeletal muscle mass (ASM), skeletal muscle mass index (SMI) and BF% were calculated using population formulas. Dietary habits, energy intake, expenditure and energy balance were derived throughout standard procedures. A successful ageing index ranging from 0 to 10 was used. The mean ASM mass was 24±6.0kg, the SMI was 0.84±0.21 and the BF% was 44%. Females had lower SMI and higher BF% in comparison with males, respectively [(SMI: 0.66±0.09 vs. 1.03±0.11; BF%: 51% vs. 34%, (pageing, while changes in BF% [b-coefficient (95% CI): -0.04 (-0.05 to -0.03)] were inversely associated with successful ageing. Results from sensitivity analysis showed that the effects of variations on body composition were consistent, less pronounced in the positive energy balance group and more pronounced among the oldest old. Body composition changes seem to be associated with lower quality of life in the older adults, as measured through successful ageing. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  4. High insulin-like growth factor-binding protein-1 (IGFBP-1) is associated with low relative muscle mass in older women

    DEFF Research Database (Denmark)

    Stilling, Frej; Wallenius, Sara; Michaëlsson, Karl

    2017-01-01

    . In the present study we investigate the association between serum IGFBP-1 and muscle mass. Design Cross-sectional analysis of 4908 women, between 55 and 85 years old, participating in the Swedish Mammography Cohort-Clinical. Methods We defined low relative muscle mass (LRMM) as an appendicular lean mass divided...... relative muscle mass. High IGFBP-1 may be a marker of a catabolic state.......Objective Skeletal muscles serve several important roles in maintaining good health. Insulin-like growth factor-1 (IGF-1) is a promoter of protein synthesis in skeletal muscle. Its binding protein, Insulin-like growth factor-binding protein-1 (IGFBP-1) can be one determinant of IGF-1 activity...

  5. Influence of hamstring muscles extensibility on spinal curvatures and pelvic tilt in highly trained cyclists.

    Science.gov (United States)

    Muyor, José M; Alacid, Fernando; López-Miñarro, Pedro A

    2011-09-01

    The purpose of this study was to determine the influence of hamstring muscles extensibility in standing, maximal trunk flexion with knees extended and on the bicycle in lower handlebar-hands position of highly trained cyclists. Ninety-six cyclists were recruited for the study (mean ± SD, age: 30.36 ± 5.98 years). Sagittal spinal curvatures and pelvic tilt were measured in the standing position, maximal trunk flexion with knees extended (sit-and-reach test) and while sitting on a bicycle in lower handlebar-hand position using a Spinal Mouse system. Hamstring muscles extensibility was determined in both legs by passive straight leg raise test (PSLR). The sample was divided into three groups according to PSLR angle: (1) reduced extensibility (PSLR hamstring extensibility group (PSLR = 80º - 90º; n = 35), and (3) high hamstring extensibility (PSLR = > 90º; n = 31). ANOVA analysis showed significant differences among groups for thoracic (p hamstring muscles extensibility influence the thoracic and pelvic postures when maximal trunk flexion with knees extended is performed, but not when cyclists are seated on their bicycles.

  6. Muscle structure, sarcomere length and influences on meat quality: A review.

    Science.gov (United States)

    Ertbjerg, Per; Puolanne, Eero

    2017-10-01

    The basic contractile unit of muscle, the sarcomere, will contract as the muscle goes into rigor post-mortem. Depending on the conditions, such as the rate of pH decline, the cooling rate and the mechanical restraints on the muscles, this longitudinal shortening will result in various post-mortem sarcomere lengths as well as lateral differences in the distances between the myosin and actin filaments. This shortening is underlying the phenomena described as rigor contraction, thaw rigor, cold shortening and heat shortening. The shortening in combination with the molecular architecture of the sarcomere as defined by the myosin filaments and their S-1 and S-2 units, the interaction with the actin filaments, and the boundaries formed by the Z-disks will subsequently influence basic meat quality traits including tenderness and water-holding capacity. Biochemical reactions from proteolysis and glycogen metabolism interrelate with the sarcomere length in a complex manner. The sarcomere length is also influencing the eating quality of cooked meat and the water-holding in meat products. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Influence of early pH decline on calpain activity in porcine muscle

    DEFF Research Database (Denmark)

    Pomponio, Luigi; Ertbjerg, Per; Karlsson, Anders H

    2010-01-01

    myofibril fragmentation at 24 h post-mortem was observed, which was no longer evident in the later phase of the tenderization process. In conclusion, the rate of early pH decline influenced l-calpain activity and the rate but not the extent of myofibrillar degradation, suggesting an early effect......This study investigated the influence of post-mortem pH decline on calpain activity and myofibrillar degradation.From 80 pigs, 30 Longissimus dorsi (LD) muscles were selected on the basis of pH values at 3 h post-mortem and classified into groups of 10 as fast, intermediate and slow pH decline...... measured. A faster decrease in pH resulted in reduced level of l-calpain activity and increased autolysis of the enzyme, and hence an earlier loss of activity due to activation of l-calpain in muscles with a fast pH decline. Paralleling the l-calpain activation in muscles with a fast pH decline a higher...

  8. Slow movement resistance training using body weight improves muscle mass in the elderly: A randomized controlled trial.

    Science.gov (United States)

    Tsuzuku, S; Kajioka, T; Sakakibara, H; Shimaoka, K

    2018-04-01

    To examine the effect of a 12-week slow movement resistance training using body weight as a load (SRT-BW) on muscle mass, strength, and fat distribution in healthy elderly people. Fifty-three men and 35 women aged 70 years old or older without experience in resistance training participated, and they were randomly assigned to a SRT-BW group or control group. The control group did not receive any intervention, but participants in this group underwent a repeat measurement 12 weeks later. The SRT-BW program consisted of 3 different exercises (squat, tabletop push-up, and sit-up), which were designed to stimulate anterior major muscles. Initially, these exercises were performed by 2 sets of 10 repetitions, and subsequently, the number of repetitions was increased progressively by 2 repetitions every 4 weeks. Participants were instructed to perform each eccentric and concentric phase of movement slowly (spending 4 seconds on each movement), covering the full range of motion. We evaluated muscle mass, strength, and fat distribution at baseline and after 12 weeks of training. Changes over 12 weeks were significantly greater in the SRT-BW group than in the control group, with a decrease in waist circumference, hip circumference, and abdominal preperitoneal and subcutaneous fat thickness, and an increase in thigh muscle thickness, knee extension strength, and hip flexion strength. In conclusion, relatively short-term SRT-BW was effective in improving muscle mass, strength, and fat distribution in healthy elderly people. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  9. Recumbent vs. upright bicycles: 3D trajectory of body centre of mass, limb mechanical work, and operative range of propulsive muscles.

    Science.gov (United States)

    Telli, Riccardo; Seminati, Elena; Pavei, Gaspare; Minetti, Alberto Enrico

    2017-03-01

    Recumbent bicycles (RB) are high performance, human-powered vehicles. In comparison to normal/upright bicycles (NB) the RB may allow individuals to reach higher speeds due to aerodynamic advantages. The purpose of this investigation was to compare the non-aerodynamic factors that may potentially influence the performance of the two bicycles. 3D body centre of mass (BCoM) trajectory, its symmetries, and the components of the total mechanical work necessary to sustain cycling were assessed through 3D kinematics and computer simulations. Data collected at 50, 70, 90 110 rpm during stationary cycling were used to drive musculoskeletal modelling simulation and estimate muscle-tendon length. Results demonstrated that BCoM trajectory, confined in a 15-mm side cube, changed its orientation, maintaining a similar pattern across all cadences in both bicycles. RB displayed a reduced additional mechanical external power (16.1 ± 9.7 W on RB vs. 20.3 ± 8.8 W on NB), a greater symmetry on the progression axis, and no differences in the internal mechanical power compared to NB. Simulated muscle activity revealed small significant differences for only selected muscles. On the RB, quadriceps and gluteus demonstrated greater shortening, while biceps femoris, iliacus, and psoas exhibited greater stretch; however, aerodynamics still remains the principal benefit.

  10. Influence of acute static stretching on the behavior of maximum muscle strength

    Directory of Open Access Journals (Sweden)

    Carmen Lúcia Borges Bastos

    2014-06-01

    Full Text Available The aim of this study was to compare the influence of acute static stretching on maximal muscle strength (1RM. The non-probabilistic sample consisted of 30 subjects split into two groups: static stretching (SS= 15 and without stretching group (WS= 15. Muscle strength evaluation (1RM was conducted with a Dynamometer model 32527pp400 Pound push / pull devices coupled in knee extension (KE and bench press (BP. The Wilcoxon test for intragroup comparisons and the Kruskal-Wallis test for comparisons between groups (p< 0.05 were selected. There were no significant differences (p> 0.05 between the SS and WS in exercise KE and BP. Therefore, it can be concluded that there was no reduction in the performance of 1RM performing the exercises KE and BP when preceded by static stretching.

  11. Spring or string: does tendon elastic action influence wing muscle mechanics in bat flight?

    Science.gov (United States)

    Konow, Nicolai; Cheney, Jorn A; Roberts, Thomas J; Waldman, J Rhea S; Swartz, Sharon M

    2015-10-07

    Tendon springs influence locomotor movements in many terrestrial animals, but their roles in locomotion through fluids as well as in small-bodied mammals are less clear. We measured muscle, tendon and joint mechanics in an elbow extensor of a small fruit bat during ascending flight. At the end of downstroke, the tendon was stretched by elbow flexion as the wing was folded. At the end of upstroke, elastic energy was recovered via tendon recoil and extended the elbow, contributing to unfurling the wing for downstroke. Compared with a hypothetical 'string-like' system lacking series elastic compliance, the tendon spring conferred a 22.5% decrease in muscle fascicle strain magnitude. Our findings demonstrate tendon elastic action in a small flying mammal and expand our understanding of the occurrence and action of series elastic actuator mechanisms in fluid-based locomotion. © 2015 The Author(s).

  12. Influence of glutamate-evoked pain and sustained elevated muscle activity on blood oxygenation in the human masseter muscle.

    Science.gov (United States)

    Suzuki, Shunichi; Arima, Taro; Kitagawa, Yoshimasa; Svensson, Peter; Castrillon, Eduardo

    2017-12-01

    This study aimed to investigate the effect of glutamate-evoked masseter muscle pain on intramuscular oxygenation during rest and sustained elevated muscle activity (SEMA). Seventeen healthy individuals participated in two sessions in which they were injected with glutamate and saline in random order. Each session was divided into three, 10-min periods. During the first (period 1) and the last (period 3) 10-min periods, participants performed five intercalated 1-min bouts of masseter SEMA with 1-min periods of 'rest'. At onset of the second 10-min period, glutamate (0.5 ml, 1 M; Ajinomoto, Tokyo, Japan) or isotonic saline (0.5 ml; 0.9%) was injected into the masseter muscle and the participants kept the muscle relaxed in a resting position for 10 min (period 2). The hemodynamic characteristics of the masseter muscle were recorded simultaneously during the experiment by a laser blood-oxygenation monitor. The results demonstrated that glutamate injections caused significant levels of self-reported pain in the masseter muscle; however, this nociceptive input did not have robust effects on intramuscular oxygenation during rest or SEMA tasks. Interestingly, these findings suggest an uncoupling between acute nociceptive activity and hemodynamic parameters in both resting and low-level active jaw muscles. Further studies are needed to explore the pathophysiological significance of blood-flow changes for persistent jaw-muscle pain conditions. © 2017 Eur J Oral Sci.

  13. Propeptide-mediated inhibition of myostatin increases muscle mass through inhibiting proteolytic pathways in aged mice.

    Science.gov (United States)

    Collins-Hooper, Henry; Sartori, Roberta; Macharia, Raymond; Visanuvimol, Korntip; Foster, Keith; Matsakas, Antonios; Flasskamp, Hannah; Ray, Steve; Dash, Philip R; Sandri, Marco; Patel, Ketan

    2014-09-01

    Mammalian aging is accompanied by a progressive loss of skeletal muscle, a process called sarcopenia. Myostatin, a secreted member of the transforming growth factor-β family of signaling molecules, has been shown to be a potent inhibitor of muscle growth. Here, we examined whether muscle growth could be promoted in aged animals by antagonizing the activity of myostatin through the neutralizing activity of the myostatin propeptide. We show that a single injection of an AAV8 virus expressing the myostatin propeptide induced an increase in whole body weights and all muscles examined within 7 weeks of treatment. Our cellular studies demonstrate that muscle enlargement was due to selective fiber type hypertrophy, which was accompanied by a shift toward a glycolytic phenotype. Our molecular investigations elucidate the mechanism underpinning muscle hypertrophy by showing a decrease in the expression of key genes that control ubiquitin-mediated protein breakdown. Most importantly, we show that the hypertrophic muscle that develops as a consequence of myostatin propeptide in aged mice has normal contractile properties. We suggest that attenuating myostatin signaling could be a very attractive strategy to halt and possibly reverse age-related muscle loss. © The Author 2014. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  14. Genetic variations in the androgen receptor are associated with steroid concentrations and anthropometrics but not with muscle mass in healthy young men.

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    Hélène De Naeyer

    Full Text Available OBJECTIVE: The relationship between serum testosterone (T levels, muscle mass and muscle force in eugonadal men is incompletely understood. As polymorphisms in the androgen receptor (AR gene cause differences in androgen sensitivity, no straightforward correlation can be observed between the interindividual variation in T levels and different phenotypes. Therefore, we aim to investigate the relationship between genetic variations in the AR, circulating androgens and muscle mass and function in young healthy male siblings. DESIGN: 677 men (25-45 years were recruited in a cross-sectional, population-based sibling pair study. METHODS: Relations between genetic variation in the AR gene (CAGn, GGNn, SNPs, sex steroid levels (by LC-MS/MS, body composition (by DXA, muscle cross-sectional area (CSA (by pQCT, muscle force (isokinetic peak torque, grip strength and anthropometrics were studied using linear mixed-effect modelling. RESULTS: Muscle mass and force were highly heritable and related to age, physical activity, body composition and anthropometrics. Total T (TT and free T (FT levels were positively related to muscle CSA, whereas estradiol (E2 and free E2 (FE2 concentrations were negatively associated with muscle force. Subjects with longer CAG repeat length had higher circulating TT, FT, and higher E2 and FE2 concentrations. Weak associations with TT and FT were found for the rs5965433 and rs5919392 SNP in the AR, whereas no association between GGN repeat polymorphism and T concentrations were found. Arm span and 2D:4D finger length ratio were inversely associated, whereas muscle mass and force were not associated with the number of CAG repeats. CONCLUSIONS: Age, physical activity, body composition, sex steroid levels and anthropometrics are determinants of muscle mass and function in young men. Although the number of CAG repeats of the AR are related to sex steroid levels and anthropometrics, we have no evidence that these variations in the AR

  15. Effects of high-intensity exercise and protein supplement on muscle mass in ADL dependent older people with and without malnutrition: a randomized controlled trial.

    Science.gov (United States)

    Carlsson, M; Littbrand, H; Gustafson, Y; Lundin-Olsson, L; Lindelöf, N; Rosendahl, E; Håglin, L

    2011-08-01

    Loss of muscle mass is common among old people living in institutions but trials that evaluate interventions aimed at increasing the muscle mass are lacking. Objective, participants and intervention: This randomized controlled trial was performed to evaluate the effect of a high-intensity functional exercise program and a timed protein-enriched drink on muscle mass in 177 people aged 65 to 99 with severe physical or cognitive impairments, and living in residential care facilities. Three-month high-intensity exercise was compared with a control activity and a protein-enriched drink was compared with a placebo drink. A bioelectrical impedance spectrometer (BIS) was used in the evaluation. The amount of muscle mass and body weight (BW) were followed-up at three and six months and analyzed in a 2 x 2 factorial ANCOVA, using the intention to treat principle, and controlling for baseline values. At 3-month follow-up there were no differences in muscle mass and BW between the exercise and the control group or between the protein and the placebo group. No interaction effects were seen between the exercise and nutritional intervention. Long-term negative effects on muscle mass and BW was seen in the exercise group at the 6-month follow-up. A three month high-intensity functional exercise program did not increase the amount of muscle mass and an intake of a protein-enriched drink immediately after the exercise did not induce any additional effect on muscle mass. There were negative long-term effects on muscle mass and BW, indicating that it is probably necessary to compensate for an increased energy demand when offering a high-intensity exercise program.

  16. Increase in relative skeletal muscle mass over time and its inverse association with metabolic syndrome development: a 7-year retrospective cohort study.

    Science.gov (United States)

    Kim, Gyuri; Lee, Seung-Eun; Jun, Ji Eun; Lee, You-Bin; Ahn, Jiyeon; Bae, Ji Cheol; Jin, Sang-Man; Hur, Kyu Yeon; Jee, Jae Hwan; Lee, Moon-Kyu; Kim, Jae Hyeon

    2018-02-05

    Skeletal muscle mass was negatively associated with metabolic syndrome prevalence in previous cross-sectional studies. The aim of this study was to investigate the impact of baseline skeletal muscle mass and changes in skeletal muscle mass over time on the development of metabolic syndrome in a large population-based 7-year cohort study. A total of 14,830 and 11,639 individuals who underwent health examinations at the Health Promotion Center at Samsung Medical Center, Seoul, Korea were included in the analyses of baseline skeletal muscle mass and those changes from baseline over 1 year, respectively. Skeletal muscle mass was estimated by bioelectrical impedance analysis and was presented as a skeletal muscle mass index (SMI), a body weight-adjusted appendicular skeletal muscle mass value. Using Cox regression models, hazard ratio for developing metabolic syndrome associated with SMI values at baseline or changes of SMI over a year was analyzed. During 7 years of follow-up, 20.1% of subjects developed metabolic syndrome. Compared to the lowest sex-specific SMI tertile at baseline, the highest sex-specific SMI tertile showed a significant inverse association with metabolic syndrome risk (adjusted hazard ratio [AHR] = 0.61, 95% confidence interval [CI] 0.54-0.68). Furthermore, compared with SMI changes metabolic syndrome development were 0.87 (95% CI 0.78-0.97) for 0-1% changes and 0.67 (0.56-0.79) for > 1% changes in SMI over 1 year after additionally adjusting for baseline SMI and glycometabolic parameters. An increase in relative skeletal muscle mass over time has a potential preventive effect on developing metabolic syndrome, independently of baseline skeletal muscle mass and glycometabolic parameters.

  17. Image resolution influence on determination of resin injection rock mass

    Science.gov (United States)

    Wang, Weixing; Hakami, Eva

    2006-01-01

    In the context of nuclear waste repositories, an important approach to understanding brittle rock mass behavior to integrate new and powerful observational and numerical methods with multi-functional 3-D imaging and visualization techniques. Since 1994, Swedish Nuclear Fuel and Waste Management Company (SKB) have identified the need for a better understanding of radionuclide transport and retention processes in fractured rock. As a cooperation project between Sweden and China, we sampled a number of rock specimens for analyze rock fracture network by optical image technique. The samples are resin injected, in which way; opened fractures can be seen clearly by means of UV (Ultraviolet) light illumination. In the study period, we used different optical focuses to obtain the images from the same samples; we found that Image resolution influences on porosity determination of resin injected rock mass. This paper presents and discusses the six issues based on our research results: (1) Fracture porosity increases as camera focus distance decreases; (2) Porosity increases as illumination increases in resin injected fracture images; (3) To roughly estimate the porosity, the low resolution image can be used; (4) To collect more details of fracture information, the high resolution image is needed; (5) The resolution of image should be determined based on the aim of fracture analysis; (6) To acquire high resolution image, constructing a special illumination (standard) box maybe helpful to avoid light reflection and diffusion.

  18. Clinical effectiveness of protein and amino acid supplementation on building muscle mass in elderly people: a meta-analysis.

    Directory of Open Access Journals (Sweden)

    Zhe-rong Xu

    Full Text Available A major reason for the loss of mobility in elderly people is the gradual loss of lean body mass known as sarcopenia. Sarcopenia is associated with a lower quality of life and higher healthcare costs. The benefit of strategies that include nutritional intervention, timing of intervention, and physical exercise to improve muscle loss unclear as finding from studies investigating this issue have been inconsistent. We have performed a systematic review and meta-analysis to assess the ability of protein or amino acid supplementation to augment lean body mass or strength of leg muscles in elderly patients.Nine studies met the inclusion criteria of being a prospective comparative study or randomized controlled trial (RCT that compared the efficacy of an amino acid or protein supplement intervention with that of a placebo in elderly people (≥ 65 years for the improvement of lean body mass (LBM, leg muscle strength or reduction associated with sarcopenia.The overall difference in mean change from baseline to the end of study in LBM between the treatment and placebo groups was 0.34 kg which was not significant (P = 0.386. The overall differences in mean change from baseline in double leg press and leg extension were 2.14 kg (P = 0.748 and 2.28 kg (P = 0.265, respectively, between the treatment group and the placebo group.These results indicate that amino acid/protein supplements did not increase lean body mass gain and muscle strength significantly more than placebo in a diverse elderly population.

  19. Effect of strength training and short-term detraining on muscle mass in women aged over 50 years old

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    Maryam Delshad

    2013-01-01

    Full Text Available Background: The loss of muscle mass is associated with aging. The aim of this study was to determine the effects of resistance training and detraining on muscle mass in elderly women. Methods: Twenty post-menopausal women aged ≥50 years old were enrolled. Matching for age, they were randomly assigned into control and resistance training group (RT. The intervention consisted of three sets of 10 repetitions for 10 movements with Thera-Band tubing (based on 80-100% 10-RM, three times a week, for 12 weeks and thereafter, four weeks detraining. Skinfold thickness was determined by caliper. Percentage of body fat was estimated from skinfold thickness (triceps and subscapular by McArdle method. Fat mass (FM and fat-free mass (FFM were calculated. Range of motion for trunk flexion and extension was determined. Results: During 12 weeks of intervention, significant increases were observed in 1-RM of biceps curl, FFM, trunk flexion and extension and significant decreases during four weeks detraining in RT group. The RT group demonstrated significant decreases during resistance training and increases during detraining in skinfold thickness. FFM, trunk flexion, and extension decreased and skinfold thickness, %FM, and weight of body fat increased in the control group (P < 0.05. Conclusions: Resistance training with Thera-Band enhanced strength and muscle endurance in elderly women and a 4-week detraining period had an adverse effect on muscle power. This suggests that a strength training program is an effective intervention to prevent functional reductions, and can contribute to improve neuromuscular function in older adults.

  20. Muscle mass and physical recovery in ICU: innovations for targeting of nutrition and exercise.

    Science.gov (United States)

    Wischmeyer, Paul E; Puthucheary, Zudin; San Millán, Iñigo; Butz, Daniel; Grocott, Michael P W

    2017-08-01

    We have significantly improved hospital mortality from sepsis and critical illness in last 10 years; however, over this same period we have tripled the number of 'ICU survivors' going to rehabilitation. Furthermore, as up to half the deaths in the first year following ICU admission occur post-ICU discharge, it is unclear how many of these patients ever returned home or a meaningful quality of life. For those who do survive, recent data reveals many 'ICU survivors' will suffer significant functional impairment or post-ICU syndrome (PICS). Thus, new innovative metabolic and exercise interventions to address PICS are urgently needed. These should focus on optimal nutrition and lean body mass (LBM) assessment, targeted nutrition delivery, anabolic/anticatabolic strategies, and utilization of personalized exercise intervention techniques, such as utilized by elite athletes to optimize preparation and recovery from critical care. New data for novel LBM analysis technique such as computerized tomography scan and ultrasound analysis of LBM are available showing objective measures of LBM now becoming more practical for predicting metabolic reserve and effectiveness of nutrition/exercise interventions. 13C-Breath testing is a novel technique under study to predict infection earlier and predict over-feeding and under-feeding to target nutrition delivery. New technologies utilized routinely by athletes such as muscle glycogen ultrasound also show promise. Finally, the role of personalized cardiopulmonary exercise testing to target preoperative exercise optimization and post-ICU recovery are becoming reality. New innovative techniques are demonstrating promise to target recovery from PICS utilizing a combination of objective LBM and metabolic assessment, targeted nutrition interventions, personalized exercise interventions for prehabilitation and post-ICU recovery. These interventions should provide hope that we will soon begin to create more 'survivors' and fewer victim's post

  1. Type VI collagen turnover-related peptides-novel serological biomarkers of muscle mass and anabolic response to loading in young men.

    Science.gov (United States)

    Nedergaard, Anders; Sun, Shu; Karsdal, Morten A; Henriksen, Kim; Kjær, Michael; Lou, Yunyun; He, Yi; Zheng, Qinlong; Suetta, Charlotte

    2013-12-01

    Immobilization-induced loss of muscle mass is a complex phenomenon with several parallels to sarcopenic and cachectic muscle loss. Muscle is a large organ with a protein turnover that is orders of magnitude larger than most other tissues. Thus, we hypothesize that muscle loss and regain is reflected by peptide biomarkers derived from type VI collagen processing released in the circulation. In order to test this hypothesis, we set out to develop an ELISA assay against an type VI collagen N-terminal globular domain epitope (IC6) and measured the levels of IC6 and an MMP-generated degradation fragment of collagen 6, (C6M) in a human immobilization-remobilization study setup with young (n = 11) and old (n = 9) men. They were subjected to 2 weeks of unilateral lower limb immobilization followed by 4 weeks of remobilization including thrice weekly resistance training, using the contralateral leg as internal controls. Subjects were sampled for strength, quadriceps muscle volume and blood at baseline (PRE), post-immobilization (2W), and post-remobilization (4W). Blood were subsequently analyzed for levels of the C6M and IC6 biomarkers. We subsequently tested if there was any correlation between C6M, IC6, or the C6M/IC6 ratio and muscle mass or strength at baseline. We also tested whether there was any relation between these biomarkers and changes in muscle mass or strength with immobilization or remobilization. The model produced significant loss of muscle mass and strength in the immobilized leg. This loss was bigger in young subjects than in elderly, but whereas the young recovered almost fully, the elderly had limited regrowth of muscle. We found a significant correlation between IC6 and muscle mass at baseline in young subjects (R (2) = 0.6563, p = 0.0045), but none in the elderly. We also found a significant correlation between C6M measured at the 4W time point and the change in muscle mass during remobilization, again only manifesting in the young

  2. Differences in Muscle Activity During Cable Resistance Training Are Influenced by Variations in Handle Types.

    Science.gov (United States)

    Rendos, Nicole K; Heredia Vargas, Héctor M; Alipio, Taislaine C; Regis, Rebeca C; Romero, Matthew A; Signorile, Joseph F

    2016-07-01

    Rendos, NK, Heredia Vargas, HM, Alipio, TC, Regis, RC, Romero, MA, and Signorile, JF. Differences in muscle activity during cable resistance training are influenced by variations in handle types. J Strength Cond Res 30(7): 2001-2009, 2016-There has been a recent resurgence in the use of cable machines for resistance training allowing movements that more effectively simulate daily activities and sports-specific movements. By necessity, these devices require a machine/human interface through some type of handle. Considerable data from material handling, industrial engineering, and exercise training studies indicate that handle qualities, especially size and shape, can significantly influence force production and muscular activity, particularly of the forearm muscles, which affect the critical link in activities that require object manipulation. The purpose for this study was to examine the influence of three different handle conditions: standard handle (StandH), ball handle with the cable between the index and middle fingers (BallIM), and ball handle with the cable between the middle and ring fingers (BallMR), on activity levels (rmsEMG) of the triceps brachii lateral and long heads (TriHLat, TriHLong), brachioradialis (BR), flexor carpi radialis (FCR), extensor carpi ulnaris, and extensor digitorum (ED) during eight repetitions of standing triceps pushdown performed from 90° to 0° elbow flexion at 1.5 s per contractile stage. Handle order was randomized. No significant differences were seen for triceps or BR rmsEMG across handle conditions; however, relative patterns of activation did vary for the forearm muscles by handle condition, with more coordinated activation levels for the FCR and ED during the ball handle conditions. In addition, the rmsEMG for the ED was significantly higher during the BallIM than any other condition and during the BallMR than the StandH. These results indicate that the use of ball handles with the cable passing between different fingers

  3. Lean body mass and muscle function in head and neck cancer patients and healthy individuals - results from the DAHANCA 25 study

    DEFF Research Database (Denmark)

    Lønbro, Simon; Dalgas, Ulrik; Primdahl, Hanne

    2013-01-01

    Abstract Introduction. Loss of lean body mass is common following radiotherapy in patients with head and neck squamous cell carcinoma (HNSCC) and may reduce maximal muscle strength and functional performance. However, the associations between lean body mass, muscle strength and functional...... m max gait speed, 30 s chair rise, 30 s arm curl, stair climb) from HNSCC patients from the DAHANCA 25 trials and data from 24 healthy individuals were included. Results. Lean body mass and maximal muscle strength were significantly associated according to the gender and age-adjusted linear...... regression model (p regression analyses showed that HNSCC patients expressed significant lower levels of the investigated variables after radiotherapy...

  4. Assessment of muscle mass, risk of falls and fear of falling in elderly people with diabetic neuropathy

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    Hudson Azevedo Pinheiro

    Full Text Available Abstract Objective : To assess muscle mass, risk of falls and fear of falling in elderly adults with diabetic neuropathy (DNP. Methods : 50 elderly patients with diabetes mellitus (DM and diabetic neuropathy (NPD participated in this study. Risk of falling was assessed using the Berg Balance Scale (BBS. Fear of falling was assessed by means of the Falls Efficacy Scale-International (FES-I. Muscle mass was assessed by tetrapolar bioimpedance analysis (BIA and Janssen's equation. Subjects were divided into two groups: one with a history of falls in the six months before study enrollment (G1 and the other without history of falls (G2. Results : There were statistically significant differences between G1 and G2 regarding lean body mass (p < 0.05, risk of falls as measured by the BBS (p < 0.01, and fear of falling as measured by the FES-I (p < 0.01. In addition, there was a significant correlation between the BBS and BIA (r = 0.45 and p < 0.01, showing that the greater the lean body mass, the lower the risk of falling. Conclusions : We found an association between lean mass, risk of falls and fear of falling in elderly adults with DNP and a history of falls from own height.

  5. The association of low muscle mass with soluble receptor for advanced glycation end products (sRAGE): The Korean Sarcopenic Obesity Study (KSOS).

    Science.gov (United States)

    Kim, Tae Nyun; Park, Man Sik; Lee, Eun Joo; Chung, Hye Soo; Yoo, Hye Jin; Kang, Hyun Joo; Song, Wook; Baik, Sei Hyun; Choi, Kyung Mook

    2018-03-01

    Advanced glycation end products (AGEs) are accumulated with aging in various tissues of humans. The soluble receptor for AGEs (sRAGE) exerts a protective role against the development of aging-related chronic disorders by neutralizing the action of AGEs. We investigated the implication of sRAGE on low muscle mass in Asian men and women. This cross-sectional study included a 390-participant, nondiabetic subcohort recruited within the framework of the Korean Sarcopenic Obesity Study, an ongoing prospective cohort study. Low muscle mass was defined based on the distribution of appendicular skeletal muscle mass divided by body mass index, as proposed by the Foundation for the National Institutes Sarcopenia Project. Serum sRAGE levels were significantly lower in participants with low muscle mass than in participants without low muscle mass (0.76 [0.60-1.00] ng/mL vs 0.87 [0.67-1.15] ng/mL, P = .005). In age- and sex-adjusted correlation analyses, appendicular skeletal muscle mass divided by body mass index was associated with sRAGE (r = 0.109, P = .037). Furthermore, decreased circulating levels of sRAGE are independently associated with low muscle mass (odds ratio = 0.254, P = .002) after adjusting for confounding factors, including insulin resistance and inflammatory markers. The present study shows that a low circulating level of sRAGE may be an independent risk factor for the presence of low muscle mass. Copyright © 2017 John Wiley & Sons, Ltd.

  6. Vitamin D and muscle trophicity.

    Science.gov (United States)

    Domingues-Faria, Carla; Boirie, Yves; Walrand, Stéphane

    2017-05-01

    We review recent findings on the involvement of vitamin D in skeletal muscle trophicity. Vitamin D deficiencies are associated with reduced muscle mass and strength, and its supplementation seems effective to improve these parameters in vitamin D-deficient study participants. Latest investigations have also evidenced that vitamin D is essential in muscle development and repair. In particular, it modulates skeletal muscle cell proliferation and differentiation. However, discrepancies still exist about an enhancement or a decrease of muscle proliferation and differentiation by the vitamin D. Recently, it has been demonstrated that vitamin D influences skeletal muscle cell metabolism as it seems to regulate protein synthesis and mitochondrial function. Finally, apart from its genomic and nongenomic effects, recent investigations have demonstrated a genetic contribution of vitamin D to muscle functioning. Recent studies support the importance of vitamin D in muscle health, and the impact of its deficiency in regard to muscle mass and function. These 'trophic' properties are of particular importance for some specific populations such as elderly persons and athletes, and in situations of loss of muscle mass or function, particularly in the context of chronic diseases.

  7. Feasibility of resistance training in adult McArdle patients: clinical outcomes and muscle strength and mass benefits.

    Science.gov (United States)

    Santalla, Alfredo; Munguía-Izquierdo, Diego; Brea-Alejo, Lidia; Pagola-Aldazábal, Itziar; Díez-Bermejo, Jorge; Fleck, Steven J; Ara, Ignacio; Lucia, Alejandro

    2014-01-01

    We analyzed the effects of a 4-month resistance (weight lifting) training program followed by a 2-month detraining period in 7 adult McArdle patients (5 female) on: muscle mass (assessed by DXA), strength, serum creatine kinase (CK) activity and clinical severity. Adherence to training was ≥84% in all patients and no major contraindication or side effect was noted during the training or strength assessment sessions. The training program had a significant impact on total and lower extremities' lean mass (P training by +855 g (95% confidence interval (CI): 30, 1679) and +547 g (95%CI: 116, 978), respectively, and significantly decreasing with detraining. Body fat showed no significant changes over the study period. Bench press and half-squat performance, expressed as the highest value of average muscle power (W) or force (N) in the concentric-repetition phase of both tests showed a consistent increase over the 4-month training period, and decreased with detraining. Yet muscle strength and power detraining values were significantly higher than pre-training values, indicating that a training effect was still present after detraining. Importantly, all the participants, with no exception, showed a clear gain in muscle strength after the 4-month training period, e.g., bench press: +52 W (95% CI: 13, 91); half-squat: +173 W (95% CI: 96, 251). No significant time effect (P > 0.05) was noted for baseline or post strength assessment values of serum CK activity, which remained essentially within the range reported in our laboratory for McArdle patients. All the patients changed to a lower severity class with training, such that none of them were in the highest disease severity class (3) after the intervention and, as such, they did not have fixed muscle weakness after training. Clinical improvements were retained, in all but one patient, after detraining, such that after detraining all patients were classed as class 1 for disease severity.

  8. The influence of controlled nutrition intensity on the muscle fiber characteristics in fattening pigs

    Directory of Open Access Journals (Sweden)

    Luboš Brzobohatý

    2015-03-01

    Full Text Available The aim of this study was to evaluate the influence of controlled nutrition on the selected muscle fibres indicators and carcass value in pork. The test included 72 hybrid pigs of the D x (LWD x L genotype of a balanced sex (barrows/gilts. Animals were divided into two groups; the 1st (control group was fed ad libitum, while the nutrition of the 2nd (experimental group was restricted upon reaching 80 kg of live weight. The nutritional restriction was achieved by feeding the animals with maximum dose of CFM up to 2.8 kg*day-1 (corresponding to 36.4 MJ ME*day-1, 46.76 g NS*day-1 and 23.52 g LYS*day-1. From the obtained results it is evident that the daily feed intake restriction corresponds with greater number of the MLLT muscle fibers as well as with a higher IIB type muscle fibers share, higher lean meat share and a higher shoulder proportion in the carcass.

  9. Influence of Synchronized Dead Point Elimination Crank on Cyclist Muscle Fatigue

    Directory of Open Access Journals (Sweden)

    Abdul Aziz Khadijah Akmal

    2016-01-01

    Full Text Available The aim of this study was to investigate the influence of newly proposed bicycle’s crank to crank angle setting on the Vastus Lateralis (VL and Bicep Femoris (BF muscle activity during cycling. Procedures of Conconi Test were used throughout the experiment for the data collection purpose. The muscles activities were recorded using surface electromyography and software LabChart7. The raw data were further processed in time (Root-Mean-Square, RMS and frequency (Mean Power Frequency, MPF domain. It was found that 0° crank to crank setting (similar to conventional crank to crank angle setting caused the prime mover VL (Normalized RMS = 0.119 to fatigue more than BF (Normalized RMS = 0.102. This setting is expected to decrease the cycling performance. In addition, −5° is the best crank to crank angle setting that causes least fatigue to both VL and BF. In short, to increase the cycling performance by avoiding the fatigue to the main muscles, −5° is the suggested as setting angle for the proposed crank design.

  10. Association between muscle mass and adipo-metabolic profile: a cross-sectional study in older subjects

    Directory of Open Access Journals (Sweden)

    Perna S

    2015-02-01

    Full Text Available Simone Perna,1,* Davide Guido,2,* Mario Grassi,2 Mariangela Rondanelli1 1Department of Public Health, Experimental and Forensic Medicine, School of Medicine, Endocrinology and Nutrition Unit, University of Pavia, Azienda di Servizi alla Persona di Pavia, Pavia, Italy; 2Medical and Genomic Statistics Unit, Department of Brain and Behavioral Sciences, University of Pavia, Pavia, Italy *These authors contributed equally to this work Background: Sarcopenia, the decrease in muscle mass and function, may lead to various negative health outcomes in elderly. The association among sarcopenia with adiposity and metabolic markers has rarely been studied in the elderly population, with controversial results. The aim of this study is to evaluate this relationship in older subjects.Methods: A cross-sectional study was conducted in 290 elderly patients, focusing on the possible association between muscle mass loss, assessed by relative skeletal muscle mass (RSMM, and an adipo-metabolic profile (AMP defined by adiposity and metabolic biochemical markers. Measurements of body composition were assessed by dual energy X-ray absorptiometry. Biochemical parameters, such as albumin, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, total cholesterol, triglycerides, C-reactive protein, and homocysteine and its related markers (folate and vitamin B12 were measured. Using canonical correlation analysis and structural equation modeling, an individual score of AMP was created and correlated with RSMM.Results: The AMP–RSMM correlation was equal to +0.642 (95% confidence interval, +0.512 to +0.773; P<0.001. Hence, a negative association between sarcopenia severity and adiposity/metabolic biochemical markers was highlighted.Conclusion: This study contained a novel way to examine the relationship between the variables of interest based on a composite index of adiposity and metabolic conditions. Results shed light on the orientation and magnitude of

  11. Ratio of Dietary n-6/n-3 Polyunsaturated Fatty Acids Independently Related to Muscle Mass Decline in Hemodialysis Patients.

    Directory of Open Access Journals (Sweden)

    Te-Chih Wong

    Full Text Available n-3 polyunsaturated fatty acids (PUFAs might be useful nutritional strategy for treating patients with sarcopenia. We evaluated the effect of the intake of dietary n-3 PUFAs on the skeletal muscle mass (SMM, appendicular skeletal muscle mass (ASM, and its determinants in patients receiving standard hemodialysis (HD treatment for the management of end stage renal disease.In this cross-sectional study, data of 111 HD patients were analyzed. Anthropometric and bioelectrical impedance measurements used to estimate the muscle mass were performed the day of dialysis immediately after the dialysis session. Routine laboratory and 3-day dietary data were also collected. The cutoff value of adequate intake (AI for both n-3 PUFAs and alpha-linolenic acid (ALA was 1.6 g/day and 1.1 g/day for men and women, respectively.The mean age, mean dietary n-3 PUFAs intake, ALA intake, ratio of n-6/n-3 PUFAs intake, SMM, and ASM of patients were 61.4 ± 10.4 years, 2.0 ± 1.3 g/day, 1.5 ± 1.0 g/day, 9.5 ± 6.7 g/day, 23.9 ± 5.5 kg, and 17.5 ± 4.5 kg, respectively. A higher SMM and ASM significantly observed in patients who achieved an AI of n-3 PUFAs. Similar trends appeared to be observed among those patients who achieved the AI of ALA, but the difference was not significantly, except for ASM (P = 0.047. No relevant differences in demographics, laboratory and nutritional parameters were observed, regardless of whether the patients achieved an AI of n-3 PUFAs. Multivariate analysis showed that the BMI and equilibrated Kt/V were independent determinants of the muscle mass. Moreover, the ratio of n-6/n-3 PUFAs was an independent risk determinant of reduced ASM in HD patients.Patients with an AI of n-3 PUFAs had better total-body SMM and ASM. A higher dietary ratio of n-6/n-3 PUFAs seemed to be associated with a reduced muscle mass in HD patients.

  12. Ratio of Dietary n-6/n-3 Polyunsaturated Fatty Acids Independently Related to Muscle Mass Decline in Hemodialysis Patients.

    Science.gov (United States)

    Wong, Te-Chih; Chen, Yu-Tong; Wu, Pei-Yu; Chen, Tzen-Wen; Chen, Hsi-Hsien; Chen, Tso-Hsiao; Yang, Shwu-Huey

    2015-01-01

    n-3 polyunsaturated fatty acids (PUFAs) might be useful nutritional strategy for treating patients with sarcopenia. We evaluated the effect of the intake of dietary n-3 PUFAs on the skeletal muscle mass (SMM), appendicular skeletal muscle mass (ASM), and its determinants in patients receiving standard hemodialysis (HD) treatment for the management of end stage renal disease. In this cross-sectional study, data of 111 HD patients were analyzed. Anthropometric and bioelectrical impedance measurements used to estimate the muscle mass were performed the day of dialysis immediately after the dialysis session. Routine laboratory and 3-day dietary data were also collected. The cutoff value of adequate intake (AI) for both n-3 PUFAs and alpha-linolenic acid (ALA) was 1.6 g/day and 1.1 g/day for men and women, respectively. The mean age, mean dietary n-3 PUFAs intake, ALA intake, ratio of n-6/n-3 PUFAs intake, SMM, and ASM of patients were 61.4 ± 10.4 years, 2.0 ± 1.3 g/day, 1.5 ± 1.0 g/day, 9.5 ± 6.7 g/day, 23.9 ± 5.5 kg, and 17.5 ± 4.5 kg, respectively. A higher SMM and ASM significantly observed in patients who achieved an AI of n-3 PUFAs. Similar trends appeared to be observed among those patients who achieved the AI of ALA, but the difference was not significantly, except for ASM (P = 0.047). No relevant differences in demographics, laboratory and nutritional parameters were observed, regardless of whether the patients achieved an AI of n-3 PUFAs. Multivariate analysis showed that the BMI and equilibrated Kt/V were independent determinants of the muscle mass. Moreover, the ratio of n-6/n-3 PUFAs was an independent risk determinant of reduced ASM in HD patients. Patients with an AI of n-3 PUFAs had better total-body SMM and ASM. A higher dietary ratio of n-6/n-3 PUFAs seemed to be associated with a reduced muscle mass in HD patients.

  13. Low vitamin D status is associated with reduced muscle mass and impaired physical performance in frail elderly people.

    Science.gov (United States)

    Tieland, M; Brouwer-Brolsma, E M; Nienaber-Rousseau, C; van Loon, L J C; De Groot, L C P G M

    2013-10-01

    Serum 25-hydroxyvitamin D (25(OH)D) status has been associated with muscle mass, strength and physical performance in healthy elderly people. Yet, in pre-frail and frail elderly people this association has not been studied. The objective of this study was to explore the association between vitamin D intake and serum 25(OH)D status with muscle mass, strength and physical performance in a pre-frail and frail elderly population. This cross-sectional study included 127 pre-frail and frail elderly people in The Netherlands. Whole body and appendicular lean mass (ALM) (dual energy X-ray absorptiometry), leg strength (one repetition maximum), handgrip strength and physical performance (short physical performance battery) were measured, and blood samples were collected for the assessment of serum 25(OH)D status (liquid chromatography-tandem mass spectrometry). In addition, habitual dietary intake (3-day food records) and physical activity data (accelerometers) were collected. In total, 53% of the participants had a serum 25(OH)D level below 50  nmol/l. After adjustment for confounding factors, 25(OH)D status was associated with ALM (β=0.012, P=0.05) and with physical performance (β=0.020, PVitamin D intake was associated with physical performance (β=0.18, P0.05). In this frail elderly population, 25(OH)D status is low and suggests a modest association with reduced ALM and impaired physical performance. In addition, vitamin D intake tended to be associated with impaired physical performance. Our findings highlight the need for well-designed intervention trials to assess the impact of vitamin D supplementation on 25(OH)D status, muscle mass and physical performance in pre-frail and frail elderly people.

  14. Physical activity as intervention for age-related loss of muscle mass and function

    DEFF Research Database (Denmark)

    Eriksen, Christian Skou; Garde, Ellen; Reislev, Nina Linde

    2016-01-01

    insights into training-induced promotion of functional ability and independency after retirement and will help to formulate national recommendations regarding physical activity schemes for the growing population of older individuals in western societies. Results will be published in scientific peer......INTRODUCTION: Physical and cognitive function decline with age, accelerating during the 6th decade. Loss of muscle power (force×velocity product) is a dominant physical determinant for loss of functional ability, especially if the lower extremities are affected. Muscle strength training is known...... to maintain or even improve muscle power as well as physical function in older adults, but the optimal type of training for beneficial long-term training effects over several years is unknown. Moreover, the impact of muscle strength training on cognitive function and brain structure remains speculative...

  15. Protein supplementation increases muscle mass gain during prolonged resistance-type exercise training in frail elderly people: a randomized double-blind, placebo-controlled trial

    NARCIS (Netherlands)

    Tieland, C.A.B.; Dirks, M.L.; Zwaluw, van der N.L.; Verdijk, L.; Rest, van de O.; Groot, de C.P.G.M.; Loon, van L.C.

    2012-01-01

    Objectives Protein supplementation has been proposed as an effective dietary strategy to augment the skeletal muscle adaptive response to prolonged resistance-type exercise training in elderly people. Our objective was to assess the impact of protein supplementation on muscle mass, strength, and

  16. Low muscle mass is associated with metabolic syndrome only in nonobese young adults: the Korea National Health and Nutrition Examination Survey 2008-2010.

    Science.gov (United States)

    Kim, Byung Chul; Kim, Mee Kyoung; Han, Kyungdo; Lee, Sae-Young; Lee, Seung-Hwan; Ko, Seung-Hyun; Kwon, Hyuk-Sang; Merchant, Anwar T; Yim, Hyeon Woo; Lee, Won-Chul; Park, Yong Gyu; Park, Yong-Moon

    2015-12-01

    Little is known about the relationship between body composition and metabolic risk factors in young adults. We hypothesized that low muscle mass (LMM) is associated with metabolic syndrome (MetS) and its components in young adults and that the associations vary by obesity. A cross-sectional analysis was conducted using the Korea National Health and Nutrition Examination Survey data. In total, 5300 young adults aged 19 to 39 years were evaluated. Low muscle mass was defined as an appendicular skeletal muscle mass/weight less than 1 SD below the mean for each participant's corresponding sex and age group. Obesity was defined as a body mass index greater than or equal to 25 kg/m2. The prevalence of LMM was higher in obese than nonobese participants (37.6% vs. 9.6%). In the nonobese participants, the prevalence of MetS, high waist circumference, high triglycerides, and high blood pressure was significantly greater in the LMM group than in the high muscle mass group. In the nonobese group, compared with high muscle mass participants, those with LMM had odds ratios for MetS of 3.6 (95% confidence interval, 1.48-8.76; P young adults with LMM may have a high risk of MetS, especially when they are nonobese. Interventions aimed at increasing muscle mass at younger ages may have the potential to reduce MetS. Published by Elsevier Inc.

  17. Influences of Fascicle Length During Isometric Training on Improvement of Muscle Strength.

    Science.gov (United States)

    Tanaka, Hiroki; Ikezoe, Tome; Umehara, Jun; Nakamura, Masatoshi; Umegaki, Hiroki; Kobayashi, Takuya; Nishishita, Satoru; Fujita, Kosuke; Araki, Kojiro; Ichihashi, Noriaki

    2016-11-01

    Tanaka, H, Ikezoe, T, Umehara, J, Nakamura, M, Umegaki, H, Kobayashi, T, Nishishita, S, Fujita, K, Araki, K, and Ichihashi, N. Influences of fascicle length during isometric training on improvement of muscle strength. J Strength Cond Res 30(11): 3249-3255, 2016-This study investigated whether low-intensity isometric training would elicit a greater improvement in maximum voluntary contraction (MVC) at the same fascicle length, rather than the joint angle, adopted during training. Sixteen healthy women (21.8 ± 1.5 years) were randomly divided into an intervention group and a control group. Before (Pre) and after (Post) training, isometric plantarflexion MVCs were measured every 10° through the range of ankle joint position from 20° dorsiflexion to 30° plantarflexion (i.e., 6 ankle angles). Medial gastrocnemius fascicle length was also measured at each position, using B-mode ultrasound under 3 conditions of muscle activation: at rest, 30%MVC at respective angles, and MVC. Plantarflexion resistance training at an angle of 20° plantarflexion was performed 3 days a week for 4 weeks at 30%MVC using 3 sets of twenty 3-second isometric contractions. Maximum voluntary contraction in the intervention group increased at 0 and 10° plantarflexion (0°; Pre: 81.2 ± 26.5 N·m, Post: 105.0 ± 21.6 N·m, 10°; Pre: 63.0 ± 23.6 N·m, Post: 81.3 ± 20.3 N·m), which was not the angle used in training (20°). However, the fascicle length adopted in training at 20° plantarflexion and 30%MVC was similar to the value at 0 or 10° plantarflexion at MVC. Low-intensity isometric training at a shortened muscle length may be effective for improving MVC at a lengthened muscle length because of specificity of the fascicle length than the joint angle.

  18. Influence of Baseline Psychological Health on Muscle Pain During Atorvastatin Treatment.

    Science.gov (United States)

    Zaleski, Amanda L; Taylor, Beth A; Pescatello, Linda S; Dornelas, Ellen A; White, Charles Michael; Thompson, Paul D

    3-hydroxy-3-methylglutaryl coenzyme A reductase reductase inhibitors (statins) are generally well tolerated, with statin-associated muscle symptoms (SAMS) the most common side effect (~10%) seen in statin users. However, studies and clinical observations indicate that many of the self-reported SAMS appear to be nonspecific (ie, potentially not attributable to statins). Mental health and well-being influence self-perception of pain, so we sought to assess the effect of baseline well-being and depression on the development of muscle pain with 6 months of atorvastatin 80 mg/d (ATORVA) or placebo in healthy, statin-naive adults. The Psychological General Well-being Index (n = 83) and Beck Depression Inventory (n = 55) questionnaires were administered at baseline in participants (aged 59.5 ± 1.2 years) from the effect of Statins on Skeletal Muscle Function and Performance (STOMP) trial (NCT00609063). Muscle pain (Short-Form McGill Pain Questionnaire [SF-MPQ]), pain that interferes with daily life (Brief Pain Inventory [BPI]), and pain severity (BPI) were then measured before, throughout, and after treatment. At baseline, there were no differences in well-being (Psychological General Well-being Index), depression (Beck Depression Inventory), or pain measures (SF-MPQ and BPI) (P values ≥ .05) between the placebo and ATORVA groups. Baseline well-being correlated negatively with baseline BPI pain severity (r = -0.290, P = .008). Baseline depression correlated with baseline pain (SF-MPQ; r = 0.314, P = .020). Baseline well-being and depression did not predict the change in pain severity or interference after 6 months among the total sample or between groups (P values ≥ .05). Baseline well-being and depression were not significant predictors of pain after 6 months of ATORVA (P values ≥ .05). Thus, they do not appear to increase the risk of SAMS in otherwise healthy adults.

  19. The dance’s influence on muscle strength of lower limbs on the elderly

    Directory of Open Access Journals (Sweden)

    Joseane Rodrigues da Silva

    2011-09-01

    Full Text Available The aim of this study was to evaluate the influence of dance in the lower limb muscle strength on the elderly. This research has a qualitative-quantitative aproach. The sample was composed by ten elderly of both sexes, who practiced ballroom dancing classes during twelve weeks. The evaluation was performed before and after the classes and it was composed by a questionnaire with personal data and medical history, “test stand and sit in 30 seconds” and a semi-structured interview with a guiding question regarding the perception of muscular strength of the elderly. The quantitative analysis was performed using the Student’s t-test with a significance level of p<0,05%. The qualitative analysis was made according directions proposed by Minayo (1994. The evaluation of muscle strength measured by the test of sitting and standing up, showed that four participants had a decreased and six had an increase in the number of movements executed, but not existed a significant statistical difference between the values before and after intervention (p=0,1934. However, the speech of the participants showed an improvement on the perception in relation muscle strength, mobility, joviality and self-esteem. It suggests that the effect of the dance, performed in the frequency used in this study, has an effect on the well-being and psychosocial sphere of the elderly. Playful activities in physical therapy performed by groups, bringing benefits, however, it should not be an isolated activity, it should be associated with a specific training to improve muscle strength related to the needs of each elderly.

  20. Interleukin-6 production in contracting human skeletal muscle is influenced by pre-exercise muscle glycogen content

    DEFF Research Database (Denmark)

    Steensberg, A; Febbraio, M A; Osada, T

    2001-01-01

    1. Prolonged exercise results in a progressive decline in glycogen content and a concomitant increase in the release of the cytokine interleukin-6 (IL-6) from contracting muscle. This study tests the hypothesis that the exercise-induced IL-6 release from contracting muscle is linked to the intram......1. Prolonged exercise results in a progressive decline in glycogen content and a concomitant increase in the release of the cytokine interleukin-6 (IL-6) from contracting muscle. This study tests the hypothesis that the exercise-induced IL-6 release from contracting muscle is linked...... to the intramuscular glycogen availability. 2. Seven men performed 5 h of a two-legged knee-extensor exercise, with one leg with normal, and one leg with reduced, muscle glycogen content. Muscle biopsies were obtained before (pre-ex), immediately after (end-ex) and 3 h into recovery (3 h rec) from exercise in both...... legs. In addition, catheters were placed in one femoral artery and both femoral veins and blood was sampled from these catheters prior to exercise and at 1 h intervals during exercise and into recovery. 3. Pre-exercise glycogen content was lower in the glycogen-depleted leg compared with the control...

  1. Visceral obesity, fat mass/muscle mass ratio and atherogenic dyslipidemia: cross-sectional study. Riobamba, Ecuador

    Directory of Open Access Journals (Sweden)

    Tomas Marcelo Nicolalde Cifuentes

    2015-10-01

    Full Text Available Introduction: The distribution and composition of fat mass is associated with different metabolic risks. The predominance of brown visceral fat is associated with risk factors for cardiovascular disease (CVD, such as: high triglycerides and apolipoprotein B, increased LDL cholesterol, ratio triglycerides/low HDL cholesterol elevated (atherogenic dyslipidemia indicator, insulin resistance, hyperinsulinemia and cardiovascular risk (CVR. Sarcopenia and obesity may act synergistically in functional and metabolic disorders. The aim of this study was to determine the relationship between visceral obesity, fat mass/muscular mass ratio and atherogenic dyslipidemia in adult individuals in order to determine the association pattern between these variables and set strategies for focused attention.Material and Methods: In a sample of 307 subjects of both sexes (21-71 years there was measured atherogenic dyslipidemia as the ratio of triglyceride/HDL cholesterol, visceral obesity measured by bio impedance as the relative score of visceral fat, and the ratio fat mass/lean mass.Results: A cluster analysis was performed to establish the structure of association between these variables with different risk groups. Three groups were identified: the first had visceral obesity with an average relative level of visceral fat of 13.6, the second group with an average of 8.9 and in the third group were placed individuals with the lowest visceral obesity score averaging 6.5. As for the fat mass/lean mas ratio the first two groups had a similar average of this index with a value of 1.56 and 1.69 respectively and the third group with the lowest average value of 1.3. Group 1 presented visceral obesity and impaired fat mass/lean mass ratio and had a high value of triglyceride/HDL ratio 4.1. Group 2 without visceral obesity and a deterioration in the relative fat mass/lean mass ratio had a triglyceride/HDL cholesterol of 3.6 and Group 3; not recorded visceral obesity or

  2. Effect of modified fasting therapy on body weight, fat and muscle mass, and blood chemistry in patients with obesity.

    Science.gov (United States)

    Kim, Koh-Woon; Song, Mi-Yeon; Chung, Seok-Hee; Chung, Won-Seok

    2016-02-01

    The aim of this study was to investigate the effects and safety of modified fasting therapy using fermented medicinal herbs and exercise on body weight, fat and muscle mass, and blood chemistry in obese subjects. Twenty-six patients participated in a 14-day fast, during which they ingested a supplement made from fermented medicinal herbs and carbohydrates (intake: 400-600 kcal/d). The schedule included 7 prefasting relief days and 14 days of stepwise reintroduction of food. The patients also took part in an exercise program that incorporated Qigong, weight training, and walking exercises. The efficacy of treatments was observed by assessing body fat mass and muscle mass, and alanine aminotransferase (ALT), aspartate aminotransferase (AST), cholesterol, and triglycerides in each study period. Specific symptoms or side effects were reported. Body weight and body fat mass both decreased significantly by (5.16 ± 0.95) and (3.89 ± 0.79) kg (both P fasting therapy using fermented medicinal herbs and exercise could be effective and safe on obese patients.

  3. Lack of independent effect of type 2 diabetes beyond characteristic comorbidities and medications on small muscle mass exercising muscle blood flow and exercise tolerance.

    Science.gov (United States)

    Poitras, Veronica J; Bentley, Robert F; Hopkins-Rosseel, Diana H; LaHaye, Stephen A; Tschakovsky, Michael E

    2015-08-01

    Persons with type 2 diabetes (T2D) are believed to have reduced exercise tolerance; this may be partly due to impaired exercising muscle blood flow (MBF). Whether there is an impact of T2D on exercising MBF within the typical constellation of comorbidities (hypertension, dyslipidemia, obesity) and their associated medications has not been investigated. We tested the hypothesis that small muscle mass exercise tolerance is reduced in persons with T2D versus Controls (matched for age, body mass index, fitness, comorbidities, non-T2D medications) and that this is related to blunted MBF. Eight persons with T2D and eight controls completed a forearm critical force (fCFimpulse) test as a measure of exercise tolerance (10-min intermittent maximal effort forearm contractions; the average contraction impulse in the last 30 sec quantified fCFimpulse). Forearm blood flow (FBF; ultrasound) and mean arterial pressure (MAP; finger photoplethysmography) were measured; forearm vascular conductance (FVK) was calculated. Data are means ± SD, T2D versus Control. fCFimpulse was not different between groups (136.9 ± 47.3  N·sec vs. 163.1 ± 49.7 N·sec, P = 0.371) nor was the ∆FBF from rest to during exercise at fCFimpulse (502.9 ± 144.6 vs. 709.1 ± 289.2 mL/min, P = 0.092), or its determinants ∆FVK and ∆MAP (both P > 0.05), although there was considerable interindividual variability. ∆FBF was strongly related to fCFimpulse (r = 0.727, P = 0.002), providing support for the relationship between oxygen delivery and exercise tolerance. We conclude that small muscle mass exercising MBF and exercise tolerance are not impaired in representative persons with T2D versus appropriately matched controls. This suggests that peripheral vascular control impairment does not contribute to reduced exercise tolerance in this population. © 2015 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of the American Physiological Society and

  4. Comparison between clinical significance of height-adjusted and weight-adjusted appendicular skeletal muscle mass.

    Science.gov (United States)

    Furushima, Taishi; Miyachi, Motohiko; Iemitsu, Motoyuki; Murakami, Haruka; Kawano, Hiroshi; Gando, Yuko; Kawakami, Ryoko; Sanada, Kiyoshi

    2017-02-13

    This study aimed to compare relationships between height- or weight-adjusted appendicular skeletal muscle mass (ASM/Ht 2 or ASM/Wt) and risk factors for cardiometabolic diseases or osteoporosis in Japanese men and women. Subjects were healthy Japanese men (n = 583) and women (n = 1218). The study population included a young group (310 men and 357 women; age, 18-40 years) and a middle-aged and elderly group (273 men and 861 women; age, ≥41 years). ASM was measured by dual-energy X-ray absorptiometry. The reference values for class 1 and 2 sarcopenia in each sex were defined as values one and two standard deviations below the sex-specific means of the young group, respectively. The reference values for class 1 and 2 sarcopenia defined by ASM/Ht 2 were 7.77 and 6.89 kg/m 2 in men and 6.06 and 5.31 kg/m 2 in women, respectively. The reference values for ASM/Wt were 35.0 and 32.0% in men and 29.6 and 26.4% in women, respectively. In both men and women, ASM/Wt was negatively correlated with higher triglycerides (TG) and positively correlated with serum high-density lipoprotein cholesterol (HDL-C), but these associations were not found in height-adjusted ASM. In women, TG, systolic blood pressure, and diastolic blood pressure in sarcopenia defined by ASM/Wt were significantly higher than those in normal subjects, but these associations were not found in sarcopenia defined by ASM/Ht 2 . Whole-body and regional bone mineral density in sarcopenia defined by ASM/Ht 2 were significantly lower than those in normal subjects, but these associations were not found in sarcopenia defined by ASM/Wt. Weight-adjusted definition was able to identify cardiometabolic risk factors such as TG and HDL-C while height-adjusted definition could identify factors for osteoporosis.

  5. Maternal obesity influences the relationship between location of neonate fat mass and total fat mass.

    Science.gov (United States)

    Hull, H R; Thornton, J; Paley, C; Navder, K; Gallagher, D

    2015-08-01

    It is suggested that maternal obesity perpetuates offspring obesity to future generations. To determine whether location of neonate fat mass (FM: central vs. peripheral) is related to total neonate FM and whether maternal obesity influences this relationship. Neonate body composition and skin-fold thicknesses were assessed in healthy neonates (n = 371; 1-3 days old). Linear regression models examined the relationship between total FM and location of FM (central vs. peripheral). Location of FM was calculated by skin-folds: peripheral was the sum of (biceps and triceps)/2 and central was represented by the subscapular skin-fold. A significant interaction was found for location of FM and maternal obesity. Holding all predictors constant, in offspring born to non-obese mothers, a 0.5 mm increase in central FM predicted a 15 g greater total FM, whereas a 0.5 mm increase in peripheral FM predicted a 66 g greater total FM. However, in offspring born to obese mothers, a 0.5 mm increase in central FM predicted a 56 g total FM, whereas a 0.5 mm increase in peripheral FM predicted a 14 g greater total FM. The relationship between total FM and location of FM is influenced by maternal obesity. © 2014 The Authors. Pediatric Obesity © 2014 World Obesity.

  6. Muscle glycogen content and glucose uptake during exercise in humans: influence of prior exercise and dietary manipulation

    DEFF Research Database (Denmark)

    Steensberg, Adam; van Hall, Gerrit; Keller, Charlotte

    2002-01-01

    on two occasions: one after 60 min of two-legged cycling (16 h prior to the experimental trial) followed by a high carbohydrate diet (HCHO) and the other after the same exercise followed by a low carbohydrate diet (LCHO) (Series 2). Muscle glycogen was decreased by 40 % when comparing the pre-exercised......There are many factors that can influence glucose uptake by contracting skeletal muscle during exercise and although one may be intramuscular glycogen content, this relationship is at present not fully elucidated. To test the hypothesis that muscle glycogen concentration influences glucose uptake...... during exercise, 13 healthy men were studied during two series of experiments. Seven men completed 4 h of two-legged knee extensor exercise 16 h after reducing of muscle glycogen by completing 60 min of single-legged cycling (Series 1). A further six men completed 3 h of two-legged knee extensor exercise...

  7. Mechanical muscle function and lean body mass during supervised strength training and testosterone therapy in aging men with low-normal testosterone levels

    DEFF Research Database (Denmark)

    Kvorning, Thue; Christensen, Louise L; Madsen, Klavs

    2013-01-01

    To examine the effect of strength training and testosterone therapy on mechanical muscle function and lean body mass (LBM) in aging men with low-normal testosterone levels in a randomized, double-blind, placebo-controlled 24-week study.......To examine the effect of strength training and testosterone therapy on mechanical muscle function and lean body mass (LBM) in aging men with low-normal testosterone levels in a randomized, double-blind, placebo-controlled 24-week study....

  8. Sports Mass Age Therapy on the Reduction of Delayed Onset Muscle Soreness of the Quadriceps Femoris

    Directory of Open Access Journals (Sweden)

    Boguszewski Dariusz

    2014-12-01

    Full Text Available Purpose. Massage therapy is one of most commonly applied treatments during athletic training. The aim of this study was to assess the effectiveness of sports massage therapy on reducing post-exercise quadriceps muscle soreness. Methods. A sample of 29 women aged 24-26 years was divided into an experimental group (n = 15 receiving classic sports massage therapy and a control group (n = 14 given no treatment. An exercise session consisting of five sets of deep squat jumps was administered after which lower limb power as assessed via the vertical jump test. Muscle soreness was assessed using the visual analogue scale (VAS and exercise intensity with the Borg Rating of Perceived Exertion Scale. Subsequent measurements of lower limb power and muscle soreness were performed 24, 48, 72 and 96 h after the exercise session. Differences between the measurements were assessed by the Friedman and least significant difference tests while between-group comparisons involved the Mann-Whitney U test. Results. The largest decrease in lower limb power was observed between the first measurement after the exercise session and 24 h later (p < 0.01. The smallest decrease in power was observed in the massage group. The highest levels of muscle soreness were noted 24 h post-exercise in the massage group and 48 h post-exercise in the control group. The experimental group showed a decrease in muscle soreness in each subsequent measurement, with the results close to zero on the VAS 96 h postexercise. Conclusions. Massage therapy quickened recovery and improved muscle efficiency post-exercise and may serve as an effective treatment of muscle soreness. The analgesic effect of massage suggests it should be widely applied in sport, physical therapy and rehabilitation.

  9. Sex and race/ethnic disparities in the cross-sectional association between depressive symptoms and muscle mass: the Multi-ethnic Study of Atherosclerosis.

    Science.gov (United States)

    Remigio-Baker, Rosemay A; Allison, Matthew A; Schreiner, Pamela J; Carnethon, Mercedes R; Nettleton, Jennifer A; Mujahid, Mahasin S; Szklo, Moyses; Crum, Rosa M; Leuotsakos, Jeannie-Marie; Franco, Manuel; Jensky, Nicole; Golden, Sherita Hill

    2015-09-18

    The cross-sectional area of total muscle mass has been reported to decrease by about 40% for those 20-60 years of age. Depressive symptoms may discourage motivation to engage in physical activity such as strength training shown to negate muscle loss. Inflammation related to depressive symptoms may also contribute to muscle atrophy. Physiological differences by sex and race/ethnicity may also modify the association between depression and muscle mass. Evidence on the relationship between depression (or depressive symptoms) and adiposity has been mounting; however, little is known about the depressive symptoms-muscle mass association. We sought to determine the association between elevated depressive symptoms (EDS) and lean muscle mass and whether this varies by sex and race/ethnicity. Evaluating 1605 adults (45-84 years of age) from the Multi-ethnic Study of Atherosclerosis Abdominal Body Composition, Inflammation and Cardiovascular Disease Study, we examined the cross-sectional association between EDS (Center for Epidemiologic Studies for Depression Scale score≥16 and/or antidepressant use) and computed tomography-measured abdominal lean muscle mass using linear regression. Muscles were evaluated as a whole and by functionality (locomotion vs. stabilization/posture). Covariates included height, body mass index, sociodemographics, comorbidities, inflammatory markers and health behaviors (pack-years of smoking, alcohol locomotion compared to men, total intentional exercise, daily caloric intake). Sex and race/ethnicity were assessed as potential modifiers. Statistical significance was at a pdepressive symptoms had 5.9 cm2 lower lean muscle mass for locomotion compared to men without EDS, fully-adjusted (CI=-10.5, -1.4, p=0.011). This was statistically significantly different from the null finding among women (interaction p=0.05). Chinese participants with EDS had 10.2 cm2 lower abdominal lean muscle mass for locomotion compared to those without EDS (fully

  10. Factors influencing treatment results of definitive radiotherapy following transurethral surgery for muscle-invasive bladder cancer

    International Nuclear Information System (INIS)

    Abe, Tatsuyuki; Kanehira Chihiro

    1999-01-01

    To determine the prognostic factors influencing the outcome of bladder cancer patients treated with definitive radiotherapy following transurethral tumor resection (TURBT). From March 1977 through August 1991, 83 patients with muscle-invasive bladder cancer were treated with TURBT (as thoroughly as possible) and definitive radiotherapy (median total dose: 64 Gy, median fractional dose: 2 Gy). Cystectomy was performed when possible for the residual or recurrent invasive cancer following radiotherapy. The median follow-up period was 76 months. The overall survival (OS) and bladder-preserving survival (BPS) rates at 5 years were 38% and 28%, respectively. Univariate analysis indicated that depth of invasion (T2 vs T3), tumor diameter (<3 cm vs. ≥3 cm), and visible (R1) or not visible (R0) residual tumor after TURBT influenced both OS and BPS. In multivariate analysis, absence of visible residual tumor after TURBT was the only significant prognostic factor related to OS (p<0.001) and BPS (p=0.002). Five-year OS and BPS were 54% and 43% in T2-3R0 and 14% and 7% in T2-3R1, respectively. Absence of visible residual tumor after TURBT was significantly associated with better overall survival and bladder-preserving survival for muscle-invasive bladder cancer patients treated with definitive radiotherapy following TURBT. (author)

  11. Influence of experimental hyperthyroidism on skeletal muscle metabolism in the rat.

    Science.gov (United States)

    van Hardeveld, C; Kassenaar, A A

    1977-05-01

    In this study hind-limb perfusion was used to investigate the influence of thyroid hormones on some metabolic parameters in the skeletal muscle of the rat. Daily injection of 20 microng L-thyroxine (T4) per 100 g b. w. for a week caused a 25% increase in oxygen consumption. Further enlargement of the T4 dose had little additive effect. In the dose range 20--80 microng T4/100g b.w., no important changes occurred in lactate production or glucose consumption. Only at the highest T4 dose did the glucose consumption increase significantly. The most profound effect of T4 was on lipolysis. A daily dose of 20 microng T4/100 g b. w. gave a doubling of glycerol production rate, the maximum occuring at a dose of 40 microng T4/100 g b. w. Inactivation of the nervous system was without influence on the T4-induced increase in oxygen consumption. However, the T4-induced elevation of lipolysis disappeared after abolition of the nervous activity. This raises the possibility that the T4 effect on lipolysis in skeletal muscle is a potentiation of catecholamine effects. The T4-induced oxygen consumption increase might be dependent not on the lipolytic process but rather on other energy-consuming cell processes.

  12. Longitudinal, lateral and transverse axes of forearm muscles influence the crosstalk in the mechanomyographic signals during isometric wrist postures.

    Science.gov (United States)

    Islam, Md Anamul; Sundaraj, Kenneth; Ahmad, R Badlishah; Sundaraj, Sebastian; Ahamed, Nizam Uddin; Ali, Md Asraf

    2014-01-01

    In mechanomyography (MMG), crosstalk refers to the contamination of the signal from the muscle of interest by the signal from another muscle or muscle group that is in close proximity. The aim of the present study was two-fold: i) to quantify the level of crosstalk in the mechanomyographic (MMG) signals from the longitudinal (Lo), lateral (La) and transverse (Tr) axes of the extensor digitorum (ED), extensor carpi ulnaris (ECU) and flexor carpi ulnaris (FCU) muscles during isometric wrist flexion (WF) and extension (WE), radial (RD) and ulnar (UD) deviations; and ii) to analyze whether the three-directional MMG signals influence the level of crosstalk between the muscle groups during these wrist postures. Twenty, healthy right-handed men (mean ± SD: age = 26.7±3.83 y; height = 174.47±6.3 cm; mass = 72.79±14.36 kg) participated in this study. During each wrist posture, the MMG signals propagated through the axes of the muscles were detected using three separate tri-axial accelerometers. The x-axis, y-axis, and z-axis of the sensor were placed in the Lo, La, and Tr directions with respect to muscle fibers. The peak cross-correlations were used to quantify the proportion of crosstalk between the different muscle groups. The average level of crosstalk in the MMG signals generated by the muscle groups ranged from: 34.28-69.69% for the Lo axis, 27.32-52.55% for the La axis and 11.38-25.55% for the Tr axis for all participants and their wrist postures. The Tr axes between the muscle groups showed significantly smaller crosstalk values for all wrist postures [F (2, 38) = 14-63, pmovement research, especially for the examination of muscle mechanics during various types of the wrist postures.

  13. Non-neural Muscle Weakness Has Limited Influence on Complexity of Motor Control during Gait

    Directory of Open Access Journals (Sweden)

    Marije Goudriaan

    2018-01-01

    Full Text Available Cerebral palsy (CP and Duchenne muscular dystrophy (DMD are neuromuscular disorders characterized by muscle weakness. Weakness in CP has neural and non-neural components, whereas in DMD, weakness can be considered as a predominantly non-neural problem. Despite the different underlying causes, weakness is a constraint for the central nervous system when controlling gait. CP demonstrates decreased complexity of motor control during gait from muscle synergy analysis, which is reflected by a higher total variance accounted for by one synergy (tVAF1. However, it remains unclear if weakness directly contributes to higher tVAF1 in CP, or whether altered tVAF1 reflects mainly neural impairments. If muscle weakness directly contributes to higher tVAF1, then tVAF1 should also be increased in DMD. To examine the etiology of increased tVAF1, muscle activity data of gluteus medius, rectus femoris, medial hamstrings, medial gastrocnemius, and tibialis anterior were measured at self-selected walking speed, and strength data from knee extensors, knee flexors, dorsiflexors and plantar flexors, were analyzed in 15 children with CP [median (IQR age: 8.9 (2.2], 15 boys with DMD [8.7 (3.1], and 15 typical developing (TD children [8.6 (2.7]. We computed tVAF1 from 10 concatenated steps with non-negative matrix factorization, and compared tVAF1 between the three groups with a Mann-Whiney U-test. Spearman's rank correlation coefficients were used to determine if weakness in specific muscle groups contributed to altered tVAF1. No significant differences in tVAF1 were found between DMD [tVAF1: 0.60 (0.07] and TD children [0.65 (0.07], while tVAF1 was significantly higher in CP [(0.74 (0.09] than in the other groups (both p < 0.005. In CP, weakness in the plantar flexors was related to higher tVAF1 (r = −0.72. In DMD, knee extensor weakness related to increased tVAF1 (r = −0.50. These results suggest that the non-neural weakness in DMD had limited influence on

  14. Beyond Body Mass Index. Is the Body Cell Mass Index (BCMI) a useful prognostic factor to describe nutritional, inflammation and muscle mass status in hospitalized elderly?: Body Cell Mass Index links in elderly.

    Science.gov (United States)

    Rondanelli, Mariangela; Talluri, Jacopo; Peroni, Gabriella; Donelli, Chiara; Guerriero, Fabio; Ferrini, Krizia; Riggi, Emilia; Sauta, Elisabetta; Perna, Simone; Guido, Davide

    2018-06-01

    The aim of this study was to establish the effectiveness of Body Cell Mass Index (BCMI) as a prognostic index of (mal)nutrition, inflammation and muscle mass status in the elderly. A cross-sectional observational study has been conducted on 114 elderly patients (80 women and 34 men), with mean age equal to 81.07 ± 6.18 years. We performed a multivariate regression model by Structural Equation Modelling (SEM) framework. We detected the effects over a Mini Nutritional Assessment (MNA) stratification, by performing a multi-group multivariate regression model (via SEM) in two MNA nutritional strata, less and bigger (or equal) than 17. BCMI had a significant effect on albumin (β = +0.062, P = 0.001), adjusting for the other predictors of the model as Body Mass Index (BMI), age, sex, fat mass and cognitive condition. An analogous result is maintained in MNAelderly patients. Copyright © 2017 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.

  15. Influence of parity, type of delivery, and physical activity level on pelvic floor muscles in postmenopausal women.

    Science.gov (United States)

    Varella, Larissa Ramalho Dantas; Torres, Vanessa Braga; Angelo, Priscylla Helouyse Melo; Eugênia de Oliveira, Maria Clara; Matias de Barros, Alef Cavalcanti; Viana, Elizabel de Souza Ramalho; Micussi, Maria Thereza de Albuquerque Barbosa Cabral

    2016-03-01

    [Purpose] The aim of the present study was to assess the influence of parity, type of delivery, and physical activity level on pelvic floor muscles in postmenopausal women. [Subjects and Methods] This was an observational analytic cross-sectional study with a sample of 100 postmenopausal women, aged between 45 and 65 years, divided into three groups according to menopausal stage: hysterectomized and early and late postmenopause. Patients were assessed for sociodemographic and gyneco-obstetric factors and subjected to a muscle strength test and perineometry. Descriptive statistics, ANOVA, Kruskal-Wallis and multiple regression were applied. [Results] The results showed homogeneity in sociodemographic and anthropometric characteristics. There was no difference in pelvic floor muscle function among the three groups. Type of delivery, parity and physical activity level showed no influence on muscle function. [Conclusion] The findings demonstrate that parity, type of delivery, and physical activity level had no influence on pelvic floor muscle pressure in postmenopausal women. One hypothesis to explain these results is the fact that the decline in muscle function in postmenopausal women is related to the female aging process.

  16. Butyryl-cholinesterase is related to muscle mass and strength. A new biomarker to identify elderly subjects at risk of sarcopenia.

    Science.gov (United States)

    Cacciatore, Francesco; Della-Morte, David; Basile, Claudia; Curcio, Francesco; Liguori, Ilaria; Roselli, Mario; Gargiulo, Gaetano; Galizia, Gianluigi; Bonaduce, Domenico; Abete, Pasquale

    2015-01-01

    To determine the relationship between Butyryl-cholinesterase (α-glycoprotein synthesized in the liver, b-CHE) and muscle mass and strength. Muscle mass by bioimpedentiometer and muscle strength by grip strength were evaluated in 337 elderly subjects (mean age: 76.2 ± 6.7 years) admitted to comprehensive geriatric assessment. b-CHE levels were lower in sarcopenic than in nonsarcopenic elderly subjects (p elderly subjects. Thus, b-CHE may be considered to be a fair biomarker for identifying elderly subjects at risk of sarcopenia.

  17. BACK MUSCLES STRENGTH DEVELOPMENT BY MEANS OF INCREASE AND DECREASE OF EFFORT LOAD DURING GIANT SETS IN BODYBUILDING FOR MASSES

    Directory of Open Access Journals (Sweden)

    TIMNEA OLIVIA

    2013-01-01

    Full Text Available Abstract The aim of the study is to highlight methodological issues on the back muscle strength development by combining methodological procedures in masses bodybuilding.Methods. The study was conducted in three stages over a period of two months (March-April 2011, performing three workouts per week, monitoring the effective use of strength exercises to develop back muscles in the same muscle area by means of giant sets during workouts. In this context, we conducted a case study in "Tonik Fitness Club" in Bucharest, applied to two athletes of 28 and 34 years old. We recorded subjects’ evolutions during the training session, using statistical and mathematical method and graphical representation method.Results. The study content highlights the training programs depending on muscle zone and the specific methodological aspects, the weekly training program per muscle groups, the stages of study carrying out, the test and control trials applied in terms of anthropometric measurements and of back muscle strength development, and the application of the methodical procedure of effort load increase and decrease within the giant sets in a training micro-cycle.Discussion. The study focused on the training programs over two months, monitoring statistically the development of back muscle strength through the application of the procedure of effort load increase and decrease during giant sets in bodybuilding for masses. From the analysis of training programs content we noticed that three giant sets of exercises were used, performed in four series; each exercise within the giant sets was applied by means of the procedure of increasing and decreasing effort load. Study results emphasize the anthropometric measurement results: the study subjects have the age mean of 24.75, with a size of 175.2 cm and a weight of 83.75 kg at initial testing and a decrease by 2.12 kg in final testing. Regarding the chest perimeter, the inspiration is averaging 89.5 in initial

  18. Factors which modulate the rates of skeletal muscle mass loss in non-small cell lung cancer patients: a pilot study.

    Science.gov (United States)

    Atlan, Philippe; Bayar, Mohamed Amine; Lanoy, Emilie; Besse, Benjamin; Planchard, David; Ramon, Jordy; Raynard, Bruno; Antoun, Sami

    2017-11-01

    Advanced non-small cell lung cancer (NSCLC) is associated with weight loss which may reflect skeletal muscle mass (SMM) and/or total adipose tissue (TAT) depletion. This study aimed to describe changes in body composition (BC) parameters and to identify the factors unrelated to the tumor which modulate them. SMM, TAT, and the proportion of SMM to SMM + TAT were assessed with computed tomography. Estimates of each BC parameter at follow-up initiation and across time were derived from a mixed linear model of repeated measurements with a random intercept and a random slope. The same models were used to assess the independent effect of gender, age, body mass index (BMI), and initial values on changes in each BC parameter. Sixty-four patients with stage III or IV NSCLC were reviewed. The mean ± SD decreases in body weight and SMM were respectively 59 ± 3 g/week (P SMM to SMM + TAT, estimated at 37 ± 2% at baseline. SMM loss was influenced by initial BMI (P SMM values (P = 0.0002): the higher the initial BMI or SMM values, the greater the loss observed. Weight loss was greater when the initial weight was heavier (P SMM wasting in NSCLC is lower when initial SMM and BMI values are low. These exploratory findings after our attempt to better understand the intrinsic factors associated with muscle mass depletion need to be confirmed in larger studies.

  19. Dexamethasone and BCAA Failed to Modulate Muscle Mass and mTOR Signaling in GH-Deficient Rats.

    Science.gov (United States)

    Nishida, Hikaru; Ikegami, Ayaka; Kaneko, Chiaki; Kakuma, Hitomi; Nishi, Hisano; Tanaka, Noriko; Aoyama, Michiko; Usami, Makoto; Okimura, Yasuhiko

    2015-01-01

    Branched-chain amino acids (BCAAs) and IGF-I, the secretion of which is stimulated by growth hormone (GH), prevent muscle atrophy. mTOR plays a pivotal role in the protective actions of BCAA and IGF-1. The pathway by which BCAA activates mTOR is different from that of IGF-1, which suggests that BCAA and GH work independently. We tried to examine whether BCAA exerts a protective effect against dexamethasone (Dex)-induced muscle atrophy independently of GH using GH-deficient spontaneous dwarf rats (SDRs). Unexpectedly, Dex did not induce muscle atrophy assessed by the measurement of cross-sectional area (CSA) of the muscle fibers and did not increase atrogin-1, MuRF1 and REDD1 expressions, which are activated during protein degradation. Glucocorticoid (GR) mRNA levels were higher in SDRs compared to GH-treated SDRs, indicating that the low expression of GR is not the reason of the defect of Dex's action in SDRs. BCAA did not stimulate the phosphorylation of p70S6K or 4E-BP1, which stimulate protein synthesis. BCAA did not decrease the mRNA level of atrogin-1 or MuRF1. These findings suggested that Dex failed to modulate muscle mass and that BCAA was unable to activate mTOR in SDRs because these phosphorylations of p70S6K and 4E-BP1 and the reductions of these mRNAs are regulated by mTOR. In contrast, after GH supplementation, these responses to Dex were normalized and muscle fiber CSA was decreased by Dex. BCAA prevented the Dex-induced decrease in CSA. BCAA increased the phosphorylation of p70S6K and decreased the Dex-induced elevations of atrogin-1 and Bnip3 mRNAs. However, the amount of mTORC1 components including mTOR was not decreased in the SDRs compared to the normal rats. These findings suggest that GH increases mTORC1 activity but not its content to recover the action of BCAA in SDRs and that GH is required for actions of Dex and BCAA in muscles.

  20. Dexamethasone and BCAA Failed to Modulate Muscle Mass and mTOR Signaling in GH-Deficient Rats.

    Directory of Open Access Journals (Sweden)

    Hikaru Nishida

    Full Text Available Branched-chain amino acids (BCAAs and IGF-I, the secretion of which is stimulated by growth hormone (GH, prevent muscle atrophy. mTOR plays a pivotal role in the protective actions of BCAA and IGF-1. The pathway by which BCAA activates mTOR is different from that of IGF-1, which suggests that BCAA and GH work independently. We tried to examine whether BCAA exerts a protective effect against dexamethasone (Dex-induced muscle atrophy independently of GH using GH-deficient spontaneous dwarf rats (SDRs. Unexpectedly, Dex did not induce muscle atrophy assessed by the measurement of cross-sectional area (CSA of the muscle fibers and did not increase atrogin-1, MuRF1 and REDD1 expressions, which are activated during protein degradation. Glucocorticoid (GR mRNA levels were higher in SDRs compared to GH-treated SDRs, indicating that the low expression of GR is not the reason of the defect of Dex's action in SDRs. BCAA did not stimulate the phosphorylation of p70S6K or 4E-BP1, which stimulate protein synthesis. BCAA did not decrease the mRNA level of atrogin-1 or MuRF1. These findings suggested that Dex failed to modulate muscle mass and that BCAA was unable to activate mTOR in SDRs because these phosphorylations of p70S6K and 4E-BP1 and the reductions of these mRNAs are regulated by mTOR. In contrast, after GH supplementation, these responses to Dex were normalized and muscle fiber CSA was decreased by Dex. BCAA prevented the Dex-induced decrease in CSA. BCAA increased the phosphorylation of p70S6K and decreased the Dex-induced elevations of atrogin-1 and Bnip3 mRNAs. However, the amount of mTORC1 components including mTOR was not decreased in the SDRs compared to the normal rats. These findings suggest that GH increases mTORC1 activity but not its content to recover the action of BCAA in SDRs and that GH is required for actions of Dex and BCAA in muscles.

  1. Circulating levels of TNF-alpha and IL-6-relation to truncal fat mass and muscle mass in healthy elderly individuals and in patients with type-2 diabetes

    DEFF Research Database (Denmark)

    Pedersen, Maria; Bruunsgaard, Helle; Weis, Nina

    2003-01-01

    The purpose of the current study was to test the hypothesis that an altered fat distribution in elderly healthy subjects and in patients with type-2 diabetes contributes to high circulating levels of interleukin (IL)-6 and tumor necrotic factor (TNF)-alpha, which secondly is related to lower muscle...... mass. Twenty young controls, (20-35 yr), 20 healthy elderly subjects (65-80 yr) and 16 elderly patients with type 2 diabetes (65-80 yr) were included in a cross sectional study. Plasma levels of TNF-alpha and IL-6 were measured after an overnight fast. Dual-energy X-ray absorptiometry and total body...... to lower ASM and BCM in elderly men both in a univariate regression analysis and a multivariate regression analysis. In conclusion, high plasma levels of TNF-alpha and IL-6 in elderly healthy people and in patients with type 2 diabetes are associated with increased truncal fat mass, suggesting...

  2. Intestinal Microbiota Is Influenced by Gender and Body Mass Index.

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    Carmen Haro

    Full Text Available Intestinal microbiota changes are associated with the development of obesity. However, studies in humans have generated conflicting results due to high inter-individual heterogeneity in terms of diet, age, and hormonal factors, and the largely unexplored influence of gender. In this work, we aimed to identify differential gut microbiota signatures associated with obesity, as a function of gender and changes in body mass index (BMI. Differences in the bacterial community structure were analyzed by 16S sequencing in 39 men and 36 post-menopausal women, who had similar dietary background, matched by age and stratified according to the BMI. We observed that the abundance of the Bacteroides genus was lower in men than in women (P 33. In fact, the abundance of this genus decreased in men with an increase in BMI (P<0.001, Q<0.001. However, in women, it remained unchanged within the different ranges of BMI. We observed a higher presence of Veillonella (84.6% vs. 47.2%; X2 test P = 0.001, Q = 0.019 and Methanobrevibacter genera (84.6% vs. 47.2%; X2 test P = 0.002, Q = 0.026 in fecal samples in men compared to women. We also observed that the abundance of Bilophila was lower in men compared to women regardless of BMI (P = 0.002, Q = 0.041. Additionally, after correcting for age and sex, 66 bacterial taxa at the genus level were found to be associated with BMI and plasma lipids. Microbiota explained at P = 0.001, 31.17% variation in BMI, 29.04% in triglycerides, 33.70% in high-density lipoproteins, 46.86% in low-density lipoproteins, and 28.55% in total cholesterol. Our results suggest that gut microbiota may differ between men and women, and that these differences may be influenced by the grade of obesity. The divergence in gut microbiota observed between men and women might have a dominant role in the definition of gender differences in the prevalence of metabolic and intestinal inflammatory diseases.

  3. Hypertrophy Stimulation at the Onset of Type I Diabetes Maintains the Soleus but Not the EDL Muscle Mass in Wistar Rats

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    Marco A. S. Fortes

    2017-10-01

    Full Text Available Diabetes mellitus induces a reduction in skeletal muscle mass and strength. Strength training is prescribed as part of treatment since it improves glycemic control and promotes increase of skeletal muscle mass. The mechanisms involved in overload-induced muscle hypertrophy elicited at the establishment of the type I diabetic state was investigated in Wistar rats. The purpose was to examine whether the overload-induced hypertrophy can counteract the hypotrophy associated to the diabetic state. The experiments were performed in oxidative (soleus or glycolytic (EDL muscles. PI3K/Akt/mTOR protein synthesis pathway was evaluated 7 days after overload-induced hypertrophy of soleus and of EDL muscles. The mRNA expression of genes associated with different signaling pathways that control muscle hypertrophy was also evaluated: mechanotransduction (FAK, Wnt/β-catenin, myostatin, and follistatin. The soleus and EDL muscles when submitted to overload had similar hypertrophic responses in control and diabetic animals. The increase of absolute and specific twitch and tetanic forces had the same magnitude as muscle hypertrophic response. Hypertrophy of the EDL muscle from diabetic animals mostly involved mechanical loading-stimulated PI3K/Akt/mTOR pathway besides the reduced activation of AMP-activated protein kinase (AMPK and decrease of myostatin expression. Hypertrophy was more pronounced in the soleus muscle of diabetic animals due to a more potent activation of rpS6 and increased mRNA expression of insulin-like growth factor-1 (IGF-1, mechano-growth factor (MGF and follistatin, and decrease of myostatin, MuRF-1 and atrogin-1 contents. The signaling changes enabled the soleus muscle mass and force of the diabetic rats to reach the values of the control group.

  4. Hypertrophy Stimulation at the Onset of Type I Diabetes Maintains the Soleus but Not the EDL Muscle Mass in Wistar Rats

    Science.gov (United States)

    Fortes, Marco A. S.; Scervino, Maria V. M.; Marzuca-Nassr, Gabriel N.; Vitzel, Kaio F.; da Justa Pinheiro, Carlos H.; Curi, Rui

    2017-01-01

    Diabetes mellitus induces a reduction in skeletal muscle mass and strength. Strength training is prescribed as part of treatment since it improves glycemic control and promotes increase of skeletal muscle mass. The mechanisms involved in overload-induced muscle hypertrophy elicited at the establishment of the type I diabetic state was investigated in Wistar rats. The purpose was to examine whether the overload-induced hypertrophy can counteract the hypotrophy associated to the diabetic state. The experiments were performed in oxidative (soleus) or glycolytic (EDL) muscles. PI3K/Akt/mTOR protein synthesis pathway was evaluated 7 days after overload-induced hypertrophy of soleus and of EDL muscles. The mRNA expression of genes associated with different signaling pathways that control muscle hypertrophy was also evaluated: mechanotransduction (FAK), Wnt/β-catenin, myostatin, and follistatin. The soleus and EDL muscles when submitted to overload had similar hypertrophic responses in control and diabetic animals. The increase of absolute and specific twitch and tetanic forces had the same magnitude as muscle hypertrophic response. Hypertrophy of the EDL muscle from diabetic animals mostly involved mechanical loading-stimulated PI3K/Akt/mTOR pathway besides the reduced activation of AMP-activated protein kinase (AMPK) and decrease of myostatin expression. Hypertrophy was more pronounced in the soleus muscle of diabetic animals due to a more potent activation of rpS6 and increased mRNA expression of insulin-like growth factor-1 (IGF-1), mechano-growth factor (MGF) and follistatin, and decrease of myostatin, MuRF-1 and atrogin-1 contents. The signaling changes enabled the soleus muscle mass and force of the diabetic rats to reach the values of the control group. PMID:29123487

  5. The Influence of External Load on Quadriceps Muscle and Tendon Dynamics during Jumping.

    Science.gov (United States)

    Earp, Jacob E; Newton, Robert U; Cormie, Prue; Blazevich, Anthony J

    2017-11-01

    Tendons possess both viscous (rate-dependent) and elastic (rate-independent) properties that determine tendon function. During high-speed movements external loading increases both the magnitude (FT) and rate (RFDT) of tendon loading. The influence of external loading on muscle and tendon dynamics during maximal vertical jumping was explored. Ten resistance-trained men performed parallel-depth, countermovement vertical jumps with and without additional load (0%, 30%, 60%, and 90% of maximum squat lift strength), while joint kinetics and kinematics, quadriceps tendon length (LT) and patellar tendon FT and RFDT were estimated using integrated ultrasound, motion analysis and force platform data and muscle tendon modelling. Estimated FT and RFDT, but not peak LT, increased with external loading. Temporal comparisons between 0% and 90% loads revealed that FT was greater with 90% loading throughout the majority of the movement (11%-81% and 87%-95% movement duration). However, RFDT was greater with 90% load only during the early movement initiation phase (8%-15% movement duration) but was greater in the 0% load condition later in the eccentric phase (27%-38% movement duration). LT was longer during the early movement (12%-23% movement duration) but shorter in the late eccentric and early concentric phases (48%-55% movement duration) with 90% load. External loading positively influenced peak FT and RFDT but tendon strain appeared unaffected, suggesting no additive effect of external loading on patellar tendon lengthening during human jumping. Temporal analysis revealed that external loading resulted in a large initial RFDT that may have caused dynamic stiffening of the tendon and attenuated tendon strain throughout the movement. These results suggest that external loading influences tendon lengthening in both a load- and movement-dependent manner.

  6. Influence of genotype on contractile protein differentiation in different bovine muscles during foetal life

    OpenAIRE

    Gagnière , Hélène; Ménissier , François; Geay , Yves; Picard , Brigitte

    2000-01-01

    International audience; The purpose of this work was to compare muscle fibre differentiation in two genetic types: "normal charolais" and double-muscled (DM) "INRA 95" cattles displaying muscle hypertrophy. Six muscles with different contractile and metabolic characteristics in adult animal: Masseter, Diaphragma (Di), Biceps femoris (BF), Longissimus thoracis, Semitendinosus and Cutaneus trunci (CT) were excised from 60 to 260-day-old fœtuses of both genotypes. These muscles present different...

  7. Skeletal muscle growth dynamics and the influence of first-feeding diet in Atlantic cod larvae (Gadus morhua L.

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    Tu A. Vo

    2016-11-01

    Full Text Available Dynamics between hypertrophy (increase in cell size and hyperplasia (increase in cell numbers of white and red muscle in relation to body size [standard length (SL], and the influence of the first-feeding diets on muscle growth were investigated in Atlantic cod larvae (Gadus morhua. Cod larvae were fed copepod nauplii or rotifers of different nutritional qualities from 4 to 29 days post hatching (dph, Artemia nauplii from 20 to 40 dph and a formulated diet from 36 to 60 dph. The short period of feeding with cultivated copepod nauplii had a positive effect on both muscle hyperplasia and hypertrophy after the copepod/rotifer phase (19 dph, and a positive long term effect on muscle hypertrophy (60 dph. The different nutritional qualities of rotifers did not significantly affect muscle growth. We suggest here a model of the dynamics between hyperplasia and hypertrophy of red and white muscle fibre cells in relation to cod SL (4 to 30 mm, where the different red and white muscle growth phases clearly coincided with different metamorphosis stages in cod larvae. These shifts could be included as biomarkers for the different stages of development during metamorphosis. The main dietary muscle effect was that hypertrophic growth of red muscle fibres was stronger in cod larvae that were fed copepods than in larvae that were fed rotifers, both in relation to larval age and size. Red muscle fibres are directly involved in larval locomotory performance, but may also play an important role in the larval myogenesis. This can have a long term effect on growth potential and fish performance.

  8. Molecular regulation of high muscle mass in developing Blonde d'Aquitaine cattle foetuses

    Directory of Open Access Journals (Sweden)

    Isabelle Cassar-Malek

    2017-10-01

    Full Text Available The Blonde d'Aquitaine (BA is a French cattle breed with enhanced muscularity, partly attributable to a MSTN mutation. The BA m. Semitendinosus has a faster muscle fibre isoform phenotype comprising a higher proportion of fast type IIX fibres compared to age-matched Charolais (CH. To better understand the molecular network of modifications in BA compared to CH muscle, we assayed the transcriptomes of the m. Semitendinosus at 110, 180, 210 and 260 days postconception (dpc. We used a combination of differential expression (DE and regulatory impact factors (RIF to compare and contrast muscle gene expression between the breeds. Prominently developmentally regulated genes in both breeds reflected the replacement of embryonic myosin isoforms (MYL4, MYH3 with adult isoforms (MYH1 and the upregulation of mitochondrial metabolism (CKMT2, AGXT2L1 in preparation for birth. However, the transition to a fast, glycolytic muscle phenotype in the MSTN mutant BA is detectable through downregulation of various slow twitch subunits (TNNC1, MYH7, TPM3, CSRP3 beyond 210 dpc, and a small but consistent genome-wide reduction in mRNA encoding the mitoproteome. Across the breeds, NRIP2 is the regulatory gene possessing a network change most similar to that of MSTN.

  9. MSTN genotypes in Thoroughbred horses influence skeletal muscle gene expression and racetrack performance.

    Science.gov (United States)

    McGivney, Beatrice A; Browne, John A; Fonseca, Rita G; Katz, Lisa M; Machugh, David E; Whiston, Ronan; Hill, Emmeline W

    2012-12-01

    Myostatin, encoded by the MSTN gene, is a member of the TGF-β superfamily that regulates skeletal muscle development. A MSTN SNP significantly associated with Thoroughbred horse racing phenotypes has recently been identified as well as significant reductions in Thoroughbred skeletal muscle gene expression for three transcripts 400-1500 base pairs downstream of the MSTN gene following a period of training. Together, these findings indicate that MSTN genotypes may influence MSTN gene expression. To investigate this, MSTN mRNA expression was measured in biopsies from the middle gluteal muscle from 60 untrained yearling Thoroughbreds (C/C, n = 15; C/T, n = 28; T/T, n = 17) using two independent real-time qRT-PCR assays. MSTN gene expression was also evaluated in a subset (N = 33) of these animals using samples collected after a ten-month period of training. A significant association was observed between genotype and mRNA abundance for the untrained horses (assay I, P = 0.0237; assay II, P = 0.003559), with the C/C cohort having the highest MSTN mRNA levels, the T/T group the lowest levels and the C/T group intermediate levels. Following training, there was a significant decrease in MSTN mRNA (-3.35-fold; P = 6.9 × 10(-7) ), which was most apparent for the C/C cohort (-5.88-fold, P = 0.001). These data demonstrate the tight relationship between phenotype, genotype and gene expression at the MSTN gene in Thoroughbred racehorses. © 2012 The Authors, Animal Genetics © 2012 Stichting International Foundation for Animal Genetics.

  10. The influence of muscle pennation angle and cross-sectional area on contact forces in the ankle joint.

    Science.gov (United States)

    Sopher, Ran S; Amis, Andrew A; Davies, D Ceri; Jeffers, Jonathan Rt

    2017-01-01

    Data about a muscle's fibre pennation angle and physiological cross-sectional area are used in musculoskeletal modelling to estimate muscle forces, which are used to calculate joint contact forces. For the leg, muscle architecture data are derived from studies that measured pennation angle at the muscle surface, but not deep within it. Musculoskeletal models developed to estimate joint contact loads have usually been based on the mean values of pennation angle and physiological cross-sectional area. Therefore, the first aim of this study was to investigate differences between superficial and deep pennation angles within each muscle acting over the ankle and predict how differences may influence muscle forces calculated in musculoskeletal modelling. The second aim was to investigate how inter-subject variability in physiological cross-sectional area and pennation angle affects calculated ankle contact forces. Eight cadaveric legs were dissected to excise the muscles acting over the ankle. The mean surface and deep pennation angles, fibre length and physiological cross-sectional area were measured. Cluster analysis was applied to group the muscles according to their architectural characteristics. A previously validated OpenSim model was used to estimate ankle muscle forces and contact loads using architecture data from all eight limbs. The mean surface pennation angle for soleus was significantly greater (54%) than the mean deep pennation angle. Cluster analysis revealed three groups of muscles with similar architecture and function: deep plantarflexors and peroneals, superficial plantarflexors and dorsiflexors. Peak ankle contact force was predicted to occur before toe-off, with magnitude greater than five times bodyweight. Inter-specimen variability in contact force was smallest at peak force. These findings will help improve the development of experimental and computational musculoskeletal models by providing data to estimate force based on both surface and deep

  11. Influence of light-quark masses in dynamical scale breaking

    International Nuclear Information System (INIS)

    Barcelos Neto, J.; Chanda, R.

    1984-01-01

    It is demonstrated that light quark masses may significantly contribute to the logarithmic scale breaking in deep inelastic electromagnetic lepton-nucleon scattering. This is mainly due to the combination of scale variables together with large 'current' masses for u and d quarks, recently reported in the literature. Upper limits for current masses of u and d quarks, using positivity properties of the forward electromagnetic structure function F 2 of the nucleon are also estimated. (Author) [pt

  12. Influence of Skeletal Muscle Carnosine Content on Fatigue during Repeated Resistance Exercise in Recreationally Active Women

    Science.gov (United States)

    Varanoske, Alyssa N.; Hoffman, Jay R.; Church, David D.; Baker, Kayla M.; Dodd, Sarah J.; Coker, Nicholas A.; Oliveira, Leonardo P.; Dawson, Virgil L.; Stout, Jeffrey R.

    2017-01-01

    Carnosine is a naturally occurring intramuscular dipeptide that is thought to attenuate fatigue during high-intensity exercise. Carnosine content is influenced by various factors, including gender and diet. Despite research reporting that carnosine content is lower in women compared to men and lower in vegetarians compared to omnivores, no investigations have examined carnosine content in women based on dietary protein intake and its effect on muscle fatigue. Twenty recreationally active women were assigned to either a high (HI; n = 5), moderate (MOD; n = 10), or low (LO; n = 5) group based upon intramuscular carnosine content of the vastus lateralis. Each participant underwent two unilateral maximal voluntary isometric contractions (MVIC) of the knee extensors separated by an isokinetic exercise protocol consisting of five sets of 50 repeated maximal unilateral contractions. Magnitude-based inferences were used to analyze group differences. Percent decline in rate of force development and peak torque (PT) during the MVICs and changes in PT and mean torque during the muscle-fatiguing protocol were lower in HI compared to both MOD and LO. Additionally, absolute and relative dietary protein intake were greater in HI compared to MOD or LO. Results indicated that greater intramuscular carnosine content was reflective of greater dietary protein intake and that individuals with higher carnosine content displayed a greater attenuation of fatigue compared to those with lower carnosine. PMID:28880219

  13. Influence of mental workload on muscle endurance, fatigue, and recovery during intermittent static work.

    Science.gov (United States)

    Mehta, Ranjana K; Agnew, Michael J

    2012-08-01

    Most occupational tasks involve some level of mental/cognitive processing in addition to physical work; however, the etiology of work-related musculoskeletal disorders (WMSDs) due to these demands remains unclear. The aim of this study was to quantify the interactive effects of physical and mental workload on muscle endurance, fatigue, and recovery during intermittent work. Twelve participants, balanced by gender, performed intermittent static shoulder abductions to exhaustion at 15, 35, and 55% of individual maximal voluntary contraction (MVC), in the absence (control) and presence (concurrent) of a mental arithmetic task. Changes in muscular capacity were determined using endurance time, strength decline, electromyographic (EMG) fatigue indicators, muscle oxygenation, and heart rate measures. Muscular recovery was quantified through changes in strength and physiological responses. Mental workload was associated with shorter endurance times, specifically at 35% MVC, and greater strength decline. EMG and oxygenation measures showed similar changes during fatigue manifestation during concurrent conditions compared to the control, despite shorter endurance times. Moreover, decreased heart rate variability during concurrent demand conditions indicated increased mental stress. Although strength recovery was not influenced by mental workload, a slower heart rate recovery was observed after concurrent demand conditions. The findings from this study provide fundamental evidence that physical capacity (fatigability and recovery) is adversely affected by mental workload. Thus, it is critical to determine or evaluate occupational demands based on modified muscular capacity (due to mental workload) to reduce risk of WMSD development.

  14. The Influence of Radiographic Severity on the Relationship between Muscle Strength and Joint Loading in Obese Knee Osteoarthritis Patients

    Directory of Open Access Journals (Sweden)

    Jens Aaboe

    2011-01-01

    Full Text Available Objective. To investigate the relationship between knee muscle strength and the external knee adduction moment during walking in obese knee osteoarthritis patients and whether disease severity influences this relationship. Methods. This cross-sectional study included 136 elderly obese (BMI>30 adults with predominant medial knee osteoarthritis. Muscle strength, standing radiographic severity as measured by the Kellgren and Lawrence scale, and the peak external knee adduction moment were measured at self-selected walking speed. Results. According to radiographic severity, patients were classified as “less severe” (KL 1-2, N=73 or “severe” (KL 3-4, N=63. A significant positive association was demonstrated between the peak knee adduction moment and hamstring muscle strength in the whole cohort (P=.047. However, disease severity did not influence the relationship between muscle strength and dynamic medial knee joint loading. Severe patients had higher peak knee adduction moment and more varus malalignment (P<.001. Conclusion. Higher hamstring muscle strength relates to higher estimates of dynamic knee joint loading in the medial compartment. No such relationship existed for quadriceps muscle strength. Although cross sectional, the results suggest that hamstrings function should receive increased attention in future studies and treatments that aim at halting disease progression.

  15. Impact of low skeletal muscle mass and density on short and long-term outcome after resection of stage I-III colorectal cancer.

    Science.gov (United States)

    van Vugt, Jeroen L A; Coebergh van den Braak, Robert R J; Lalmahomed, Zarina S; Vrijland, Wietske W; Dekker, Jan W T; Zimmerman, David D E; Vles, Wouter J; Coene, Peter-Paul L O; IJzermans, Jan N M

    2018-06-06

    Preoperative low skeletal muscle mass and density are associated with increased postoperative morbidity in patients undergoing curative colorectal cancer (CRC) surgery. However, the long-term effects of low skeletal muscle mass and density remain uncertain. Patients with stage I-III CRC undergoing surgery, enrolled in a prospective observational cohort study, were included. Skeletal muscle mass and density were measured on CT. Patients with high and low skeletal muscle mass and density were compared regarding postoperative complications, disease-free survival (DFS), overall survival (OS), and cancer-specific survival (CSS). In total, 816 patients (53.9% males, median age 70) were included; 50.4% had low skeletal muscle mass and 64.1% low density. The severe postoperative complication rate was significantly higher in patients with low versus high skeletal muscle and density (20.9% versus 13.6%, p = 0.006; 20.0% versus 11.8%, p = 0.003). Low skeletal muscle mass (OR 1.91, p = 0.018) and density (OR 1.87, p = 0.045) were independently associated with severe postoperative complications. Ninety-day mortality was higher in patients with low skeletal muscle mass and density compared with patients with high skeletal muscle mass and density (3.6% versus 1.7%, p = 0.091; 3.4% versus 1.0%, p = 0.038). No differences in DFS were observed. After adjustment for covariates such as age and comorbidity, univariate differences in OS and CSS diminished. Low skeletal muscle mass and density are associated with short-term, but not long-term, outcome in patients undergoing CRC surgery. These findings recommend putting more emphasis on preoperative management of patients at risk for surgical complications, but do not support benefit for long-term outcome. Copyright © 2018 Elsevier Ltd, BASO ~ The Association for Cancer Surgery, and the European Society of Surgical Oncology. All rights reserved.

  16. Influence of Lateral Muscle Loading in the Proximal Femur after Fracture Stabilization with a Trochanteric Gamma Nail (TGN)

    Science.gov (United States)

    Sitthiseripratip, Kriskrai; Mahaisavariya, Banchong; Suwanprateeb, Jintamai; Bohez, Erik; Vander Sloten, Jos

    The purpose of this study was to investigate the influence of lateral muscle loading on the stress/strain distributions of the trochanteric Gamma nail (TGN) fixation within the healed, trochanteric and subtrochanteric femoral fractures by means of a finite element method. The effect of three muscle groups, the abductors (ABD), the vastus lateralis (VL) and the iliotibial band (ITB), were investigated. The analytical results showed that addition of lateral muscle forces, iliotibial band and vastus lateralis, produced compensation of forces and reduction of bending moments in the bone and in the trochanteric Gamma nail especially in the lateral aspect. The iliotibial band produced a higher impact as compared to the vastus lateralis. Therefore in the finite element analysis of the proximal femur with the trochanteric Gamma nail fracture fixation should include the lateral muscle forces to simulate load condition with maximal physiological relevance to the closed nailing technique.

  17. Influence of pre-exercise muscle glycogen content on exercise-induced transcriptional regulation of metabolic genes

    DEFF Research Database (Denmark)

    Pilegaard, Henriette; Keller, Charlotte; Steensberg, Adam

    2002-01-01

    Transcription of metabolic genes is transiently induced during recovery from exercise in skeletal muscle of humans. To determine whether pre-exercise muscle glycogen content influences the magnitude and/or duration of this adaptive response, six male subjects performed one-legged cycling exercise...... to lower muscle glycogen content in one leg and then, the following day, completed 2.5 h low intensity two-legged cycling exercise. Nuclei and mRNA were isolated from biopsies obtained from the vastus lateralis muscle of the control and reduced glycogen (pre-exercise glycogen = 609 +/- 47 and 337 +/- 33...... mmol kg(-1) dry weight, respectively) legs before and after 0, 2 and 5 h of recovery. Exercise induced a significant (P glycogen leg only. Although PDK4...

  18. Influence of different sports on fat mass and lean mass in growing girls

    Directory of Open Access Journals (Sweden)

    Esther Ubago-Guisado

    2017-06-01

    Conclusion: Impact sports (football, basketball, and handball and low-impact sports (swimming provide an appropriate development of lean mass in growing girls. We can conclude that people practicing sports at early ages ensure a lower fat mass and higher lean mass compared to those who do not practice. These results may be useful as a preventive method of adult obesity.

  19. The Influence of the Mass Media on Young People as a Problem of Russian Pedagogy

    Science.gov (United States)

    Zapesotskii, A. S.

    2011-01-01

    An analysis of the influence of the mass media on the moral state of Russian society discerns negative consequences of that influence, and sees the mass media (particularly television) as involved in the cultural degradation of the population. It argues in favor of state, social, and pedagogical controls to facilitate a more positive role of the…

  20. Creation of a contusion injury in rabbit skeletal muscle using a drop-mass technique

    Directory of Open Access Journals (Sweden)

    Margaret N. Deane

    2013-08-01

    Full Text Available This study reports our experience in developing a simple, minor injury. After reviewing the literature, a ‘drop-mass’ method was selected where a 201 g, elongated oval-shaped weight was dropped up to 15 times through a 1 m tube onto the left vastus lateralis of New Zealand white rabbits. To determine the extent of injury and degree of healing, biopsies were obtained six days after injury from the healing vastus lateralis of each animal. The tissue was fixed in formal saline, embedded in wax, cut and stained with haematoxylin and eosin (H&E and phosphotungstic acid haematoxylin (PTAH and examined by light microscopy (LM. The ‘optimal’ injury was created after seven drops, where quite severe, mild and moderately severe trauma was caused to muscle in the juxta-bone, mid and sub-dermal regions respectively. In each region, the muscle exhibited features of healing six days after injury. The ‘drop-mass’ technique appears to cause a contusion within a single muscle of at least three degrees of severity. This previously unreported observation is of particular importance to other researchers wishing to investigate contusion injury in other animal models.

  1. The effect of protein intake and resistance training on muscle mass in acutely ill old medical patients - A randomized controlled trial

    DEFF Research Database (Denmark)

    Buhl, Sussi F; Andersen, Aino L; Andersen, Jens Rikardt

    2016-01-01

    admission and a daily protein supplement (18.8 g protein) and resistance training 3 times per week the 12 weeks following discharge. Muscle mass was assessed by Dual-energy X-ray Absorptiometry. Muscle strength was assessed by Hand Grip Strength and Chair Stand Test. Functional ability was assessed...... mass (unadjusted: β-coefficient = -1.28 P = 0.32, adjusted for gender: β-coefficient = -0.02 P = 0.99, adjusted for baseline lean mass: β-coefficient = -0.31 P = 0.80). The de Morton Mobility Index significantly increased in the Control Group (β-coefficient = -11.43 CI: 0.72-22.13, P = 0.04). No other...... differences were found. CONCLUSION: No significant effect on muscle mass was observed in this group of acutely ill old medical patients. High compliance was achieved with the dietary intervention, but resistance training was challenging. Clinical trials identifier NCT02077491....

  2. Age-related differences in lean mass, protein synthesis and skeletal muscle markers of proteolysis after bed rest and exercise rehabilitation.

    Science.gov (United States)

    Tanner, Ruth E; Brunker, Lucille B; Agergaard, Jakob; Barrows, Katherine M; Briggs, Robert A; Kwon, Oh Sung; Young, Laura M; Hopkins, Paul N; Volpi, Elena; Marcus, Robin L; LaStayo, Paul C; Drummond, Micah J

    2015-09-15

    Bed rest-induced muscle loss and impaired muscle recovery may contribute to age-related sarcopenia. It is unknown if there are age-related differences in muscle mass and muscle anabolic and catabolic responses to bed rest. A secondary objective was to determine if rehabilitation could reverse bed rest responses. Nine older and fourteen young adults participated in a 5-day bed rest challenge (BED REST). This was followed by 8 weeks of high intensity resistance exercise (REHAB). Leg lean mass (via dual-energy X-ray absorptiometry; DXA) and strength were determined. Muscle biopsies were collected during a constant stable isotope infusion in the postabsorptive state and after essential amino acid (EAA) ingestion on three occasions: before (PRE), after bed rest and after rehabilitation. Samples were assessed for protein synthesis, mTORC1 signalling, REDD1/2 expression and molecular markers related to muscle proteolysis (MURF1, MAFBX, AMPKα, LC3II/I, Beclin1). We found that leg lean mass and strength decreased in older but not younger adults after bedrest (P protein synthesis increased before bed rest in both age groups (P protein synthesis rates and increased MAFBX mRNA, p-AMPKα and the LC3II/I ratio (P protein synthesis and a marginal increase in proteolytic markers. Finally, rehabilitation restored bed rest-induced deficits in lean mass and strength in older adults. © 2015 The Authors. The Journal of Physiology © 2015 The Physiological Society.

  3. Effects of Eight Months of Whole-Body Vibration Training on the Muscle Mass and Functional Capacity of Elderly Women.

    Science.gov (United States)

    Santin-Medeiros, Fernanda; Rey-López, Juan P; Santos-Lozano, Alejandro; Cristi-Montero, Carlos S; Garatachea Vallejo, Nuria

    2015-07-01

    Few intervention studies have used whole-body vibration (WBV) training in the elderly, and there is inconclusive evidence about its health benefits. We examined the effect of 8 months of WBV training on muscle mass and functional capacity in elderly women. A total of 37 women (aged 82.4 ± 5.7 years) voluntarily participated in this study. Subjects were randomly assigned to a vibration group (n = 19) or a control group (n = 18). The vibration group trained on a vertical vibration platform twice a week. The control group was requested not to change their habitual lifestyle. The quadriceps femoris muscle cross-sectional area was determined by magnetic resonance imaging. All participants were evaluated by a battery of tests (Senior Fitness Test) to determine their functional capacity, as well as handgrip strength and balance/gait. General linear repeated-measure analysis of variance (group by time) was performed to examine the effect of the intervention on the outcomes variables. After 8 months, nonstatistically significant differences in the quadriceps CSA (pre-training: 8,516.16 ± 1,271.78 mm² and post-training: 8,671.63 ± 1,389.03 mm²) (p > 0.05) were found in the WBV group (Cohen's d: -0.12), whereas the CON group significantly decreased muscle mass (pre-training: 9,756.18 ± 1,420.07 mm² and post-training: 9,326.82 ± 1,577.53 mm²), with moderate effect size evident (Cohen's d: 0.29). In both groups, no changes were observed in the functional capacity, handgrip strength and balance/gait. The WBV training could prevent the loss of quadriceps CSA in elderly women.

  4. Alternate Mediterranean diet score is positively associated with skeletal muscle mass index in middle-aged adults.

    Science.gov (United States)

    Tian, Hui-Yuan; Qiu, Rui; Jing, Li-Peng; Chen, Zhan-Yong; Chen, Geng-Dong; Chen, Yu-Ming

    2017-04-01

    Researches have suggested Mediterranean diet might lower the risk of chronic diseases, but data on skeletal muscle mass (SMM) are limited. This community-based cross-sectional study examined the association between the alternate Mediterranean diet score (aMDS) and SMM in 2230 females and 1059 males aged 40-75 years in Guangzhou, China. General information and habitual dietary information were assessed in face-to-face interviews conducted during 2008-2010 and 3 years later. The aMDS was calculated by summing the dichotomous points for the items of higher intakes of whole grain, vegetables, fruits, legumes, nuts, fish and ratio of MUFA:SFA, lower red meat and moderate ethanol consumption. The SMM of the whole body, limbs, arms and legs were measured using dual-energy X-ray absorptiometry during 2011-2013. After adjusting for potential covariates, higher aMDS was positively associated with skeletal muscle mass index (SMI, SMM/height2, kg/m2) at all of the studied sites in males (all P trend0·05). Age-stratified analyses showed that the favourable associations tended to be more pronounced in the younger subjects aged less than the medians of 59·2 and 62·2 years in females and males (P interaction>0·10). In conclusion, the aMDS shows protective associations with SMM in Chinese adults, particularly in male and younger subjects.

  5. Feasibility of resistance training in adult McArdle patients: Clinical outcomes and muscle strength and mass benefits

    Directory of Open Access Journals (Sweden)

    Alfredo eSantalla

    2014-12-01

    Full Text Available We analyzed the effects of a 4-month resistance (weight lifting training program followed by a 2-month detraining period in 7 adult McArdle patients (5 female on: muscle mass (assessed by DXA, strength, serum creatine kinase (CK activity and clinical severity. Adherence to training was ≥ 84% in all patients and no major contraindication or side effect was noted during the training or strength assessment sessions. The training program had a significant impact on total and lower extremities’ lean mass (P0.05 was noted for baseline or post strength assessment values of serum CK activity, which remained essentially within the range reported in our laboratory for McArdle patients. All the patients changed to a lower severity class with training, such that none of them were in the highest disease severity class (3 after the intervention and, as such, they did not have fixed muscle weakness after training. Clinical improvements were retained, in all but one patient, after detraining, such that after detraining all patients were classed as class 1 for

  6. Similar muscles contribute to horizontal and vertical acceleration of center of mass in forward and backward walking: implications for neural control

    Science.gov (United States)

    Jansen, Karen; De Groote, Friedl; Massaad, Firas; Meyns, Pieter; Jonkers, Ilse

    2012-01-01

    Leg kinematics during backward walking (BW) are very similar to the time-reversed kinematics during forward walking (FW). This suggests that the underlying muscle activation pattern could originate from a simple time reversal, as well. Experimental electromyography studies have confirmed that this is the case for some muscles. Furthermore, it has been hypothesized that muscles showing a time reversal should also exhibit a reversal in function [from accelerating the body center of mass (COM) to decelerating]. However, this has not yet been verified in simulation studies. In the present study, forward simulations were used to study the effects of muscles on the acceleration of COM in FW and BW. We found that a reversal in function was indeed present in the muscle control of the horizontal movement of COM (e.g., tibialis anterior and gastrocnemius). In contrast, muscles' antigravity contributions maintained their function for both directions of movement. An important outcome of the present study is therefore that similar muscles can be used to achieve opposite functional demands at the level of control of the COM when walking direction is reversed. However, some muscles showed direction-specific contributions (i.e., dorsiflexors). We concluded that the changes in muscle contributions imply that a simple time reversal would be insufficient to produce BW from FW. We therefore propose that BW utilizes extra elements, presumably supraspinal, in addition to a common spinal drive. These additions are needed for propulsion and require a partial reconfiguration of lower level common networks. PMID:22423005

  7. Application of the relativistic mean-field mass model to the r-process and the influence of mass uncertainties

    International Nuclear Information System (INIS)

    Sun, B.; Montes, F.; Geng, L. S.; Geissel, H.; Litvinov, Yu. A.; Meng, J.

    2008-01-01

    A new mass table calculated by the relativistic mean-field approach with the state-dependent BCS method for the pairing correlation is applied for the first time to study r-process nucleosynthesis. The solar r-process abundance is well reproduced within a waiting-point approximation approach. Using an exponential fitting procedure to find the required astrophysical conditions, the influence of mass uncertainty is investigated. The r-process calculations using the FRDM, ETFSI-Q, and HFB-13 mass tables have been used for that purpose. It is found that the nuclear physical uncertainty can significantly influence the deduced astrophysical conditions for the r-process site. In addition, the influence of the shell closure and shape transition have been examined in detail in the r-process simulations

  8. Influence of gravity compensation on muscle activity during reach and retrieval in healthy elderly.

    NARCIS (Netherlands)

    Prange, Grada Berendina; Kallenberg, L.A.C.; Jannink, M.J.A.; Stienen, Arno; van der Kooij, Herman; IJzerman, Maarten Joost; Hermens, Hermanus J.

    2007-01-01

    INTRODUCTION: Arm support like gravity compensation may improve arm movements during stroke rehabilitation. It is unknown how gravity compensation affects muscle activation patterns during reach and retrieval movements. Since muscle activity during reach is represented by a component varying with

  9. Influence of botulinum toxin on rabbit jaw muscle activity and anatomy.

    Science.gov (United States)

    Korfage, J A M; Wang, Jeffrey; Lie, S H J T J; Langenbach, Geerling E J

    2012-05-01

    Muscles can adapt their fiber properties to accommodate to new conditions. We investigated the extent to which a decrease in muscle activation can cause an adaptation of fiber properties in synergistic and antagonistic jaw muscles. Three months after the injection of botulinum toxin type A in one masseter (anterior or posterior) muscle changes in fiber type composition and fiber cross-sectional areas in jaw muscles were studied at the microscopic level. The injected masseter showed a steep increase in myosin type IIX fibers, whereas fast fibers decreased by about 50% in size. Depending on the injection site, both synergistic and antagonistic muscles showed a significant increase in the size of their fast IIA fibers, sometimes combined with an increased number of IIX fibers. Silencing the activity in the masseter not only causes changes in the fibers of the injected muscle but also leads to changes in other jaw muscles. Copyright © 2012 Wiley Periodicals, Inc.

  10. Influence of impurities on the polaron effective mass

    International Nuclear Information System (INIS)

    Lima, R.A.T. de.

    1975-01-01

    Using the Green Function formalism, it is verified the Rodriguez's model for the effective mass of the polaron at finite temperature in the presence of 'traps'. Some aspects of this model were discussed. (M.W.O.) [pt

  11. Influence of successive badminton matches on muscle strength, power, and body-fluid balance in elite players.

    Science.gov (United States)

    Abian-Vicen, Javier; Castanedo, Adrián; Abian, Pablo; Gonzalez-Millan, Cristina; Salinero, Juan José; Del Coso, Juan

    2014-07-01

    The aim was to analyze the influence of competitive round on muscle strength, body-fluid balance, and renal function in elite badminton players during a real competition. Body mass, jump height during a countermovement jump, handgrip force, and urine samples were obtained from 13 elite badminton players (6 men and 7 women) before and after the 2nd-round and quarterfinal matches of the national Spanish badminton championship. Sweat rate was determined by using prematch-to-postmatch body-mass change and by weighing individually labeled fluid bottles. Sweat rates were 1.04 ± 0.62 and 0.98 ± 0.43 L/h, while rehydration rate was 0.69 ± 0.26 and 0.91 ± 0.52 L/h for the 2nd round and quarterfinals, respectively. Thus, dehydration was 0.47% ± 1.03% after the 2nd round and 0.23% ± 0.43% after the quarterfinals. There were no differences in prematch-to-postmatch jump height, but jump height was reduced from 37.51 ± 8.83 cm after the 2nd-round game to 34.82 ± 7.37 cm after the quarterfinals (P badminton competition were effective to prevent dehydration. A badminton match did not affect jump height or handgrip force, but jump height was progressively reduced by the competitive round. Badminton players' renal responses reflected diminished renal flux due to the high-intensity nature of this racket sport.

  12. Social percolation and the influence of mass media

    Science.gov (United States)

    Proykova, Ana; Stauffer, Dietrich

    2002-09-01

    In the marketing model of Solomon and Weisbuch, people buy a product only if their neighbours tell them of its quality, and if this quality is higher than their own quality expectations. Now we introduce additional information from the mass media, which is analogous to the ghost field in percolation theory. The mass media shift the percolative phase transition observed in the model, and decrease the time after which the stationary state is reached.

  13. Influence of botulinum toxin on rabbit jaw muscle activity and anatomy

    NARCIS (Netherlands)

    Korfage, J.A.M.; Wang, J.; Lie, S.H.J.T.J.; Langenbach, G.E.J.

    2012-01-01

    Introduction: Muscles can adapt their fiber properties to accommodate to new conditions. We investigated the extent to which a decrease in muscle activation can cause an adaptation of fiber properties in synergistic and antagonistic jaw muscles. Methods: Three months after the injection of botulinum

  14. The Association between Total Protein and Vegetable Protein Intake and Low Muscle Mass among the Community-Dwelling Elderly Population in Northern Taiwan

    Directory of Open Access Journals (Sweden)

    Ru-Yi Huang

    2016-06-01

    Full Text Available Sarcopenia, highly linked with fall, frailty, and disease burden, is an emerging problem in aging society. Higher protein intake has been suggested to maintain nitrogen balance. Our objective was to investigate whether pre-sarcopenia status was associated with lower protein intake. A total of 327 community-dwelling elderly people were recruited for a cross-sectional study. We adopted the multivariate nutrient density model to identify associations between low muscle mass and dietary protein intake. The general linear regression models were applied to estimate skeletal muscle mass index across the quartiles of total protein and vegetable protein density. Participants with diets in the lowest quartile of total protein density (<13.2% were at a higher risk for low muscle mass (odds ratio (OR 3.03, 95% confidence interval (CI 1.37–6.72 than those with diets in the highest quartile (≥17.2%. Similarly, participants with diets in the lowest quartile of vegetable protein density (<5.8% were at a higher risk for low muscle mass (OR 2.34, 95% CI 1.14–4.83 than those with diets in the highest quartile (≥9.4%. Furthermore, the estimated skeletal muscle mass index increased significantly across the quartiles of total protein density (p = 0.023 and vegetable protein density (p = 0.025. Increasing daily intakes of total protein and vegetable protein densities appears to confer protection against pre-sarcopenia status.

  15. Influence of Gravity Compensation on Muscle Activation Patterns During Different Temporal Phases of Arm Movements of Stroke Patients

    NARCIS (Netherlands)

    Prange, Grada Berendina; Jannink, M.J.A.; Stienen, Arno; van der Kooij, Herman; IJzerman, Maarten Joost; Hermens, Hermanus J.

    2009-01-01

    Background. Arm support to help compensate for the effects of gravity may improve functional use of the shoulder and elbow during therapy after stroke, but gravity compensation may alter motor control. Objective. To obtain quantitative information on how gravity compensation influences muscle

  16. Increased Muscular 5α-Dihydrotestosterone in Response to Resistance Training Relates to Skeletal Muscle Mass and Glucose Metabolism in Type 2 Diabetic Rats.

    Directory of Open Access Journals (Sweden)

    Naoki Horii

    Full Text Available Regular resistance exercise induces skeletal muscle hypertrophy and improvement of glycemic control in type 2 diabetes patients. Administration of dehydroepiandrosterone (DHEA, a sex steroid hormone precursor, increases 5α-dihydrotestosterone (DHT synthesis and is associated with improvements in fasting blood glucose level and skeletal muscle hypertrophy. Therefore, the aim of this study was to investigate whether increase in muscle DHT levels, induced by chronic resistance exercise, can contribute to skeletal muscle hypertrophy and concomitant improvement of muscular glucose metabolism in type 2 diabetic rats. Male 20-week-old type 2 diabetic rats (OLETF were randomly divided into 3 groups: sedentary control, resistance training (3 times a week on alternate days for 8 weeks, or resistance training with continuous infusion of a 5α-reductase inhibitor (n = 8 each group. Age-matched, healthy nondiabetic Long-Evans Tokushima Otsuka (LETO rats (n = 8 were used as controls. The results indicated that OLETF rats showed significant decrease in muscular DHEA, free testosterone, DHT levels, and protein expression of steroidogenic enzymes, with loss of skeletal muscle mass and hyperglycemia, compared to that of LETO rats. However, 8-week resistance training in OLETF rats significantly increased the levels of muscle sex steroid hormones and protein expression of steroidogenic enzymes with a concomitant increase in skeletal muscle mass, improved fasting glucose level, and insulin sensitivity index. Moreover, resistance training accelerated glucose transporter-4 (GLUT-4 translocation and protein kinase B and C-ζ/λ phosphorylation. Administering the 5α-reductase inhibitor in resistance-trained OLETF rats resulted in suppression of the exercise-induced effects on skeletal muscle mass, fasting glucose level, insulin sensitivity index, and GLUT-4 signaling, with a decline in muscular DHT levels. These findings suggest that resistance training

  17. Ultrasound evaluation of muscle thickness changes in the external oblique, internal oblique, and transversus abdominis muscles considering the influence of posture and muscle contraction.

    Science.gov (United States)

    Sugaya, Tomoaki; Abe, Yota; Sakamoto, Masaaki

    2014-09-01

    [Purpose] The aim of this study was to investigate muscle thickness changes in the external oblique (EO), internal oblique (IO), and transversus abdominis (TrA) muscles between the neutral position and trunk rotation, under a state of rest without voluntary contractions, and isometric contractions to both sides with resistance of 50% of the maximum trunk rotation strength. [Subjects] The subjects of this study were 21 healthy young men. [Methods] Muscle thickness changes in the EO, IO, and TrA in each position and state were evaluated by ultrasound. The range of motion at maximum trunk rotation and the maximum strength of trunk rotation were measured using a hand-held dynamometer. [Results] In the neutral position and at 50% trunk rotation to the right side, the thicknesses of the IO and TrA significantly increased with resistance. In both states, the thicknesses of the IO and TrA significantly increased at 50% trunk rotation to the right side. [Conclusion] The muscular contractions of the IO and TrA were stronger during ipsilateral rotation than in the neutral position and with resistance than at rest. Moreover, the muscular contraction was strongest in the resistive state during ipsilateral rotation.

  18. The influence of thyroarytenoid and cricothyroid muscle activation on vocal fold stiffness and eigenfrequencies

    Science.gov (United States)

    Yin, Jun; Zhang, Zhaoyan

    2013-01-01

    The influence of the thyroarytenoid (TA) and cricothyroid (CT) muscle activation on vocal fold stiffness and eigenfrequencies was investigated in a muscularly controlled continuum model of the vocal folds. Unlike the general understanding that vocal fold fundamental frequency was determined by vocal fold tension, this study showed that vocal fold eigenfrequencies were primarily determined by vocal fold stiffness. This study further showed that, with reference to the resting state of zero strain, vocal fold stiffness in both body and cover layers increased with either vocal fold elongation or shortening. As a result, whether vocal fold eigenfrequencies increased or decreased with CT/TA activation depended on how the CT/TA interaction influenced vocal fold deformation. For conditions of strong CT activation and thus an elongated vocal fold, increasing TA contraction reduced the degree of vocal fold elongation and thus reduced vocal fold eigenfrequencies. For conditions of no CT activation and thus a resting or slightly shortened vocal fold, increasing TA contraction increased the degree of vocal fold shortening and thus increased vocal fold eigenfrequencies. In the transition region of a slightly elongated vocal fold, increasing TA contraction first decreased and then increased vocal fold eigenfrequencies. PMID:23654401

  19. Strong Relation between Muscle Mass Determined by D3-creatine Dilution, Physical Performance and Incidence of Falls and Mobility Limitations in a Prospective Cohort of Older Men.

    Science.gov (United States)

    Cawthon, Peggy M; Orwoll, Eric S; Peters, Katherine E; Ensrud, Kristine E; Cauley, Jane A; Kado, Deborah M; Stefanick, Marcia L; Shikany, James M; Strotmeyer, Elsa S; Glynn, Nancy W; Caserotti, Paolo; Shankaran, Mahalakshmi; Hellerstein, Marc; Cummings, Steven R; Evans, William J

    2018-06-12

    Direct assessment of skeletal muscle mass in older adults is clinically challenging. Relationships between lean mass and late-life outcomes have been inconsistent. The D3-creatine dilution method provides a direct assessment of muscle mass. Muscle mass was assessed by D3-creatine (D3Cr) dilution in 1,382 men (mean age, 84.2 yrs). Participants completed the Short Physical Performance Battery (SPPB); usual walking speed (6 meters); and DXA lean mass. Men self-reported mobility limitations (difficulty walking 2-3 blocks or climbing 10 steps); recurrent falls (2+); and serious injurious falls in the subsequent year. Across quartiles of D3Cr muscle mass/body mass, multivariate linear models calculated means for SPPB and gait speed; multivariate logistic models calculated odds ratios for incident mobility limitations or falls. Compared to men in the highest quartile, those in the lowest quartile of D3Cr muscle mass/body mass had slower gait speed (Q1: 1.04 vs Q4: 1.17 m/s); lower SPPB (Q1: 8.4 vs Q4: 10.4 points); greater likelihood of incident serious injurious falls (OR Q1 vs Q4: 2.49, 95% CI: 1.37, 4.54); prevalent mobility limitation (OR Q1 vs Q4,: 6.1, 95%CI: 3.7, 10.3) and incident mobility limitation (OR Q1 vs Q4: 2.15 95% CI: 1.42, 3.26); p for trend strongly related to physical performance, mobility and incident injurious falls in older me.

  20. Age-associated declines in muscle mass, strength, power, and physical performance: impact on fear of falling and quality of life.

    Science.gov (United States)

    Trombetti, A; Reid, K F; Hars, M; Herrmann, F R; Pasha, E; Phillips, E M; Fielding, R A

    2016-02-01

    This 3-year longitudinal study among older adults showed that declining muscle mass, strength, power, and physical performance are independent contributing factors to increased fear of falling, while declines of muscle mass and physical performance contribute to deterioration of quality of life. Our findings reinforce the importance of preserving muscle health with advancing age. The age-associated loss of skeletal muscle quantity and function are critical determinants of independent physical functioning in later life. Longitudinal studies investigating how decrements in muscle components of sarcopenia impact fear of falling (FoF) and quality of life (QoL) in older adults are lacking. Twenty-six healthy older subjects (age, 74.1 ± 3.7; Short Physical Performance Battery (SPPB) score ≥10) and 22 mobility-limited older subjects (age, 77.2 ± 4.4; SPPB score ≤9) underwent evaluations of lower extremity muscle size and composition by computed tomography, strength and power, and physical performance at baseline and after 3-year follow-up. The Falls Efficacy Scale (FES) and Short Form-36 questionnaire (SF-36) were also administered at both timepoints to assess FoF and QoL, respectively. At 3-year follow-up, muscle cross-sectional area (CSA) (p < 0.013) and power decreased (p < 0.001), while intermuscular fat infiltration increased (p < 0.001). These decrements were accompanied with a longer time to complete 400 m by 22 ± 46 s (p < 0.002). Using linear mixed-effects regression models, declines of muscle CSA, strength and power, and SPPB score were associated with increased FES score (p < 0.05 for each model). Reduced physical component summary score of SF-36 over follow-up was independently associated with decreased SPPB score (p < 0.020), muscle CSA (p < 0.046), and increased 400 m walk time (p < 0.003). In older adults with and without mobility limitations, declining muscle mass, strength, power, and physical

  1. Influence of spinal sagittal alignment, body balance, muscle strength, and physical ability on falling of middle-aged and elderly males.

    Science.gov (United States)

    Imagama, Shiro; Ito, Zenya; Wakao, Norimitsu; Seki, Taisuke; Hirano, Kenichi; Muramoto, Akio; Sakai, Yoshihito; Matsuyama, Yukihiro; Hamajima, Nobuyuki; Ishiguro, Naoki; Hasegawa, Yukiharu

    2013-06-01

    Risk factors for falling in elderly people remain uncertain, and the effects of spinal factors and physical ability on body balance and falling have not been examined. The objective of this study was to investigate how factors such as spinal sagittal alignment, spinal range of motion, body balance, muscle strength, and gait speed influence falling in the prospective cohort study. The subjects were 100 males who underwent a basic health checkup. Balance, SpinalMouse(®) data, grip strength, back muscle strength, 10-m gait time, lumbar lateral standing radiographs, body mass index, and fall history over the previous year were examined. Platform measurements of balance included the distance of movement of the center of pressure (COP) per second (LNG/TIME), the envelopment area traced by movement of the COP (E AREA), and the LNG/E AREA ratio. The thoracic/lumbar angle ratio (T/L ratio) and sagittal vertical axis (SVA) were used as an index of sagittal balance. LNG/TIME and E AREA showed significant positive correlations with age, T/L ratio, SVA, and 10-m gait time; and significant negative correlations with lumbar lordosis angle, sacral inclination angle, grip strength and back muscle strength. Multiple regression analysis showed significant differences for LNG/TIME and E AREA with T/L ratio, SVA, lumbar lordosis angle and sacral inclination angle (R (2) = 0.399). Twelve subjects (12 %) had experienced a fall over the past year. Age, T/L ratio, SVA, lumbar lordosis angle, sacral inclination angle, grip strength, back muscle strength, 10-m gait time, height of the intervertebral disc, osteophyte formation in radiographs and LNG/E AREA differed significantly between fallers and non-fallers. The group with SVA > 40 mm (n = 18) had a significant higher number of subjects with a single fall (6 single fallers/18: p = 0.0075) and with multiple falls (4 multiple fallers/18: p = 0.0095). Good spinal sagittal alignment, muscle strength and 10-m gait speed improve body balance

  2. Influence of 103Pd radioactive stent on apoptosis of vascular smooth muscle cells

    International Nuclear Information System (INIS)

    Liu Yingmei; Wu Wei; Chen Xiaochao; Zhang Xuming; Wang Jingfeng; Wei Yulin; Yang Li

    2003-01-01

    Objective: To evaluate the influence of 103 Pd radioactive stent on apoptosis and its relative genes bcl-2 and bax in injured vascular media smooth muscle cells of rabbit abdominal arteries and to investigate the mechanism of 103 Pd radioactive stent for preventing restenosis after angioplasty. Methods: Fifty male New Zealand rabbits were randomized into stent group and 103 Pd stent group. Each group was subdivided into 5 sub-groups. Control group was set up. The study arteries were harvested at 3, 7, 14, 28 and 56 d after stenting and the pathomorphology, apoptosis analysis and in situ hybridization were performed to evaluate the expression of bcl-2 and bax mRNA. Results: The severity of the restenosis in 103 Pd stent group was less than that of stent group. It was most obvious at the 56th day (P 103 Pd stent group had much more apoptosis of vascular smooth muscle cells than stent group did and reached the peak at the 7th day, (14.72±0.53)% vs (12.42±1.13)% (P 103 Pd stent group was much lower than that of stent group at 3 to 28 d. The difference was most obvious at the 28th day after stenting, (18.43± 0.67)% vs (21.55±0.93)% (P 103 Pd stent group was higher than that of stent group, the peak was at the 7th day, (11.17±0.94)% vs (9.30±1.01)%. The ratio of bcl-2/bax in 103 Pd stent group was much lower than that of stent group at 3 to 28 d. Linear correlation analysis showed that there was significant negative correlation between bcl-2 mRNA and apoptosis. Between bax mRNA and apoptosis, the positive correlation was found (P 103 Pd radioactive stent induced more significant apoptosis in vascular media smooth muscle cells by promoting the expression of apoptosis related genes and relieved the expanding of restenosis

  3. The influence of altered working-side occlusal guidance on masticatory muscles and related jaw movement.

    Science.gov (United States)

    Belser, U C; Hannam, A G

    1985-03-01

    The effect of four different occlusal situations (group function, canine guidance, working side occlusal interference, and hyperbalancing occlusal interference) on EMG activity in jaw elevator muscles and related mandibular movement was investigated on 12 subjects. With a computer-based system, EMG and displacement signals were collected simultaneously during specific functional (unilateral chewing) and parafunctional tasks (mandibular gliding movements and various tooth clenching efforts) and analyzed quantitatively. When a naturally acquired group function was temporarily and artificially changed into a dominant canine guidance, a significant general reduction of elevator muscle activity was observed when subjects exerted full isometric tooth-clenching efforts in a lateral mandibular position. The original muscular coordination pattern (relative contraction from muscle to muscle) remained unaltered during this test. With respect to unilateral chewing, no significant alterations in the activity or coordination of the muscles occurred when an artificial canine guidance was introduced. Introduction of a hyperbalancing occlusal contact caused significant alterations in muscle activity and coordination during maximal tooth clenching in a lateral mandibular position. A marked shift of temporal muscle EMG activity toward the side of the interference and unchanged bilateral activity of the two masseter muscles were observed. The results suggest that canine-protected occlusions do not significantly alter muscle activity during mastication but significantly reduce muscle activity during parafunctional clenching. They also suggest that non-working side contacts dramatically alter the distribution of muscle activity during parafunctional clenching, and that this redistribution may affect the nature of reaction forces at the temporomandibular joints.

  4. The magnitude of muscle strain does not influence serial sarcomere number adaptations following eccentric exercise.

    Science.gov (United States)

    Butterfield, Timothy A; Herzog, Walter

    2006-02-01

    It is generally accepted that eccentric exercise, when performed by a muscle that is unaccustomed to that type of contraction, results in a delayed onset of muscle soreness (DOMS). A prolonged exposure to eccentric exercise leads to the disappearance of the signs and symptoms associated with DOMS, which has been referred to as the repeated bout effect (RBE). Although the mechanisms underlying the RBE remain unclear, several mechanisms have been proposed, including the serial sarcomere number addition following exercise induced muscle damage. In the traditional DOMS and RBE protocols, muscle injury has been treated as a global parameter, with muscle force and strain assumed to be uniform throughout the muscle. To assess the effects of muscle-tendon unit strain, fiber strain, torque and injury on serial sarcomere number adaptations, three groups of New Zealand White (NZW) rabbits were subjected to chronic repetitive eccentric exercise bouts of the ankle dorsiflexors for 6 weeks. These eccentric exercise protocols consisted of identical muscle tendon unit (MTU) strain, but other mechanical factors were systematically altered. Following chronic eccentric exercise, serial sarcomere number adaptations were not identical between the three eccentric exercise protocols, and serial sarcomere number adaptations were not uniform across all regions of the muscle. Peak torque and relaxation fiber strain were the best predictors of serial sarcomere number across all three protocols. Therefore, MTU strain does not appear to be the primary cause for sarcomerogenesis, and differential adaptations within the muscle may be explained by the nonuniform architecture of the muscle, resulting in differential local fiber strains.

  5. Muscle dysmorphia: risk may be influenced by goals of the weightlifter.

    Science.gov (United States)

    Skemp, Karen M; Mikat, Richard P; Schenck, Kyle P; Kramer, Natalie A

    2013-09-01

    Athletes with muscle dysmorphia suffer from constant dissatisfaction with body size and shape because they perceive themselves as smaller and less muscular than they actually are. There may be discrepancies among the various subgroups within the weightlifting community in regards to vulnerability and susceptibility to the development of MD. The purpose of this study, therefore, was to examine and compare MD symptomology between male and female, competitive and noncompetitive, and appearance-related and performance-related weightlifters. The MD assessments were made with the muscle dysmorphia inventory (MDI). The participants included 85 competitive (55 men and 30 women) and 48 noncompetitive (24 men and 24 women) weight training athletes. Each group included athletes with a primary focus on appearance enhancement or performance enhancement. Factorial analyses of variance were used to measure differences between each group on all MDI subscales. The results showed that men scored significantly higher than did women on the supplement (p = 0.006), physique protection (p = 0.039), and body size and symmetry subscales (p < 0.001). Competitive athletes scored significantly higher than noncompetitive athletes did on diet (p < 0.001), supplement (p < 0.001), exercise dependence (p < 0.001), and body size and symmetry (p = 0.002) subscales. Finally, the athletes focused on appearance enhancement scored significantly higher than athletes focused on performance enhancement on all 6 subscales (p < 0.01). Coaches and health and fitness professionals should understand that the goals of athletes in regard to weight training can influence susceptibility to development of MD symptoms. Knowing that athletes who engage in weight training to enhance appearance may exhibit greater behavioral characteristics than those athletes who do not may be helpful so they may be able to identify, prevent, and reverse MD in the athletes they serve.

  6. The influence of training status on the drop in muscle strength after acute exercise

    DEFF Research Database (Denmark)

    Pingel, Jessica; Moerch, L; Kjaer, M

    2009-01-01

    to running exercise immediately after immobilization, the muscle strength of the triceps-surae muscles dropped even further, but just in the immobilized leg (41%; P importance of determining the muscle endurance when evaluating the effect of immobilization on muscle......Skeletal muscles fatigue after exercise, and reductions in maximal force appear. A difference in training status between the legs was introduced by unilateral immobilization of the calf muscles for 2 weeks in young men, who were randomly assigned to two groups, either a RUN group (n = 8......) that was exposed to prolonged exercise (1-h running: individual pace) or a REST group (n = 12) that did no exercise after immobilization. Cross-sectional area (CSA) of the triceps-surae muscles was calculated by magnetic resonance imaging (MRI), and maximal voluntary contraction (MVC) force of the plantar flexors...

  7. Modifiable environmental influences on body mass index shared by young adult brothers

    DEFF Research Database (Denmark)

    Rokholm, B; Silventoinen, K; Tynelius, P

    2013-01-01

    Twin and adoption studies suggest that family environment has little, if any, influence on body mass index (BMI) in adulthood. We investigated the hypothesis that the differences in the years of birth between siblings influence their similarity in BMI at comparable ages, which would give evidence...... for a possibly modifiable influence of the environment shared by family members....

  8. Mass Media Influences on Public Conceptions of Social Problems

    Science.gov (United States)

    Hubbard, Jeffrey C.; And Others

    1975-01-01

    Explores possible relationships between the mass media of communication and social problems by three-way comparisons between the incidence of social problems suggested in media portrayals, conceptions of the incidence of these problems held by the public, and the relative frequency of such problems reflected in statistics accumulated by official…

  9. The obesity paradox in men with coronary heart disease and heart failure: the role of muscle mass and leptin.

    Science.gov (United States)

    Wannamethee, S Goya; Shaper, A Gerald; Whincup, Peter H; Lennon, Lucy; Papacosta, Olia; Sattar, Naveed

    2014-01-15

    We have investigated the role of muscle mass, natriuretic peptides and adipokines in explaining the obesity paradox. The obesity paradox relates to the association between obesity and increased survival in patients with coronary heart disease (CHD) or heart failure (HF). Prospective study of 4046 men aged 60-79 years followed up for a mean period of 11 years, during which 1340 deaths occurred. The men were divided according to the presence of doctor diagnosed CHD and HF: (i) no CHD or HF ii), with CHD (no HF) and (iii) with HF. Overweight (BMI 25-9.9 kg/m(2)) and obesity (BMI ≥ 30 kg/m(2)) were associated with lower mortality risk compared to men with normal weight (BMI 18.5-24.9 kg/m(2)) in those with CHD [hazards ratio (HR) 0.71 (0.56,0.91) and 0.77 (0.57,1.04); p=0.04 for trend] and in those with HF [HR 0.57 (0.28,1.16) and 0.41 (0.16,1.09; p=0.04 for trend). Adjustment for muscle mass and NT-proBNP attenuated the inverse association in those with CHD (no HF) [HR 0.78 (0.61,1.01) and 0.96 (0.68,1.36) p=0.60 for trend) but made minor differences to those with HF [p=0.05]. Leptin related positively to mortality in men without HF but inversely to mortality in those with HF; adjustment for leptin abolished the BMI mortality association in men with HF [HR 0.82 (0.31,2.20) and 0.99 (0.27,3.71); p=0.98 for trend]. The lower mortality risk associated with excess weight in men with CHD without HF may be due to higher muscle mass. In men with HF, leptin (possibly reflecting cachexia) explain the inverse association. Copyright © 2013. Published by Elsevier Ireland Ltd.

  10. Comparison between body mass index, triceps skin fold thickness and mid-arm muscle circumference in Saudi adolescents

    International Nuclear Information System (INIS)

    Abdalkhail, B.; Shawky, S.

    2002-01-01

    Adolescence is an important period in an individual's life. Overweight and obesity are fraught with several health problems even late in life. The objective of this study was estimate the overweight, obesity, body fat and muscle content of Saudi adolescents as compared to a recognized reference population. Data were collected from a sample of Saudi adolescents in Jeddah from 42 boys' and 42 girls' school during the month of April 2000. Data collection was done by personal interviews to collect sociodemograhic factors and by direct measurement of weight, height, triceps skin fold thickness (TSF) and mid-arm circumference (MAC). The 50th, 85th and 95th percentiles(P50, P85 and P95) for body mass index (BMI) and triceps skin fold thickness (TSF) were taken, then the 50th, 90th, and 95th percentiles (P50, P90 and P95) for the mid-arm muscle circumference (MAMC) were calculated. These measurements were compared with corresponding values of the National Health and Nutrition Examination Survey I (NHANES I). The P85 and P95 for the BMI and TSF were higher for Saudi adolescents than the NHANES I and the difference was wider for P95. Conversely, there was a lower MAMC at P90 and P95thane the NHANES I reference population curves. The lower MAMC curves were less marked in girls than in boys. On the other hand Saudi boys and girls showed on average similar body mass index indicated by MBI at P50, which was misleading, since those adolescents showing similar body mass index had more fatness than of average reference population indicated by TSF and P50, and less muscularity on average than reference population indicated MAMC at P-50. Overweight and obesity with increased body fat content and decreased body muscle content appear to be widespread among Saudi adolescents even among those adolescents showing average body index. Public health interventions are required to improve quality of food, encourage physical, activity and exercise, as well as correct the perception of

  11. Longitudinal, lateral and transverse axes of forearm muscles influence the crosstalk in the mechanomyographic signals during isometric wrist postures.

    Directory of Open Access Journals (Sweden)

    Md Anamul Islam

    Full Text Available In mechanomyography (MMG, crosstalk refers to the contamination of the signal from the muscle of interest by the signal from another muscle or muscle group that is in close proximity.The aim of the present study was two-fold: i to quantify the level of crosstalk in the mechanomyographic (MMG signals from the longitudinal (Lo, lateral (La and transverse (Tr axes of the extensor digitorum (ED, extensor carpi ulnaris (ECU and flexor carpi ulnaris (FCU muscles during isometric wrist flexion (WF and extension (WE, radial (RD and ulnar (UD deviations; and ii to analyze whether the three-directional MMG signals influence the level of crosstalk between the muscle groups during these wrist postures.Twenty, healthy right-handed men (mean ± SD: age = 26.7±3.83 y; height = 174.47±6.3 cm; mass = 72.79±14.36 kg participated in this study. During each wrist posture, the MMG signals propagated through the axes of the muscles were detected using three separate tri-axial accelerometers. The x-axis, y-axis, and z-axis of the sensor were placed in the Lo, La, and Tr directions with respect to muscle fibers. The peak cross-correlations were used to quantify the proportion of crosstalk between the different muscle groups.The average level of crosstalk in the MMG signals generated by the muscle groups ranged from: 34.28-69.69% for the Lo axis, 27.32-52.55% for the La axis and 11.38-25.55% for the Tr axis for all participants and their wrist postures. The Tr axes between the muscle groups showed significantly smaller crosstalk values for all wrist postures [F (2, 38 = 14-63, p<0.05, η2 = 0.416-0.769].The results may be applied in the field of human movement research, especially for the examination of muscle mechanics during various types of the wrist postures.

  12. The influence of the Peroneus Longus muscle on the foot under axial loading: A CT evaluated dynamic cadaveric model study.

    Science.gov (United States)

    Dullaert, K; Hagen, J; Klos, K; Gueorguiev, B; Lenz, M; Richards, R G; Simons, P

    2016-05-01

    Subtle hypermobility of the first tarsometatarsal joint can occur concomitantly with other pathologies and may be difficult to diagnose. Peroneus Longus muscle might influence stability of this joint. Collapse of the medial longitudinal arch is common in flatfoot deformity and the muscle might also play a role in correcting Meary's angle. A radiolucent frame was used to simulate weightbearing during CT examination. Eight pairs fresh-frozen lower legs were imaged in neutral position under non-weightbearing (75N), weightbearing (700N) and with 15kg weights hung from Peroneus Longus tendon. Measurements included first metatarsal rotation, intermetatarsal angle, first tarsometatarsal joint subluxation and Meary's angle. Weightbearing significantly increased Meary's angle and significantly decreased first tarsometatarsal joint subluxation (both Pfoot pathology. Weightbearing affects anatomy of the foot. No reliable information is available concerning the influence of the Peroneus muscle. This study investigates the influence of weightbearing and the impact the Peroneus muscle on the anatomy of the foot. Copyright © 2016. Published by Elsevier Ltd.

  13. Influence of muscle fiber type composition on early fat accumulation under high-fat diet challenge.

    Science.gov (United States)

    Hua, Ning; Takahashi, Hirokazu; Yee, Grace M; Kitajima, Yoichiro; Katagiri, Sayaka; Kojima, Motoyasu; Anzai, Keizo; Eguchi, Yuichiro; Hamilton, James A

    2017-01-01

    To investigate whether differences in muscle fiber types affect early-stage fat accumulation, under high fat diet challenge in mice. Twelve healthy male C57BL/6 mice experienced with short-term (6 weeks) diet treatment for the evaluation of early pattern changes in muscular fat. The mice were randomly divided into two groups: high fat diet (n = 8) and normal control diet (n = 4). Extra- and intra-myocellular lipid (EMCL and IMCL) in lumbar muscles (type I fiber predominant) and tibialis anterior (TA) muscle (type II fiber predominant) were determined using magnetic resonance spectroscopy (MRS). Correlation of EMCL, IMCL and their ratio between TA and lumbar muscles was evaluated. EMCL increased greatly in both muscle types after high fat diet. IMCL in TA and lumbar muscles increased to a much lower extent, with a slightly greater increase in TA muscles. EMCLs in the 2 muscles were positively correlated (r = 0.84, p = 0.01), but IMCLs showed a negative relationship (r = -0.84, p = 0.01). In lumbar muscles, high fat diet significantly decreased type I fiber while it increased type II fiber (all p≤0.001). In TA muscle, there was no significant fiber type shifting (p>0.05). Under short-time high fat diet challenge, lipid tends to initially accumulate extra-cellularly. In addition, compared to type II dominant muscle, Type I dominant muscle was less susceptible to IMCL accumulation but more to fiber type shifting. These phenomena might reflect compensative responses of skeletal muscle to dietary lipid overload in order to regulate metabolic homeostasis.

  14. Ratio of dietary ω-3 and ω-6 fatty acids-independent determinants of muscle mass-in hemodialysis patients with diabetes.

    Science.gov (United States)

    Wong, Te-Chih; Chen, Yu-Tong; Wu, Pei-Yu; Chen, Tzen-Wen; Chen, Hsi-Hsien; Chen, Tso-Hsiao; Hsu, Yung-Ho; Yang, Shwu-Huey

    2016-09-01

    ω-3 and ω-6 polyunsaturated fatty acids (PUFAs) are essential nutrients in the human diet and possibly affect muscle mass. We evaluated the association between the dietary ratios of ω-3 and ω-6 PUFAs and muscle mass, indicated as skeletal muscle mass (SMM) and appendicular skeletal muscle mass (ASM), in patients with diabetes undergoing hemodialysis (HD). In this cross-sectional study, data on 69 patients with diabetes who underwent standard HD therapy were analyzed. For estimating muscle mass, anthropometric and bioelectrical impedance analyses were conducted following dialysis. In addition, routine laboratory and 3-d dietary data were obtained. The adequate intake (AI) cut-off for ω-3 PUFAs was 1.6 g/d and 1.1 g/d for male and female patients, respectively. The average age of the participants was 63.0 ± 10.4 y. The mean ratios of ω-3/ω-6 PUFA intake, ω-6/ω-3 PUFA intake, SMM, and ASM of the patients were 0.13 ± 0.07, 9.4 ± 6.4, 24.6 ± 5.4 kg, and 18.3 ± 4.6 kg, respectively. Patients who had AI of ω-3 PUFAs had significantly higher SMM and ASM than did their counterparts. Linear and stepwise multivariable adjustment analyses revealed that insulin resistance and the ω-6/ω-3 PUFA ratio were the independent deleterious determinants of ASM normalized to height in HD patients. Patients with AI of ω-3 PUFAs had total-body SMM and ASM that were more appropriate. A higher dietary ratio of ω-6/ω-3 PUFAs was associated with reduced muscle mass in HD patients. Copyright © 2016 Elsevier Inc. All rights reserved.

  15. Influence of the boundary conditions on heat and mass transfer in spacer-filled channels

    Science.gov (United States)

    Ciofalo, M.; La Cerva, M. F.; Di Liberto, M.; Tamburini, A.

    2017-11-01

    The purpose of this study is to discuss some problems which arise in heat or mass transfer in complex channels, with special reference to the spacer-filled channels adopted in membrane processes. Among the issues addressed are the consistent definition of local and mean heat or mass transfer coefficients; the influence of the wall boundary conditions; the influence of one-side versus two-side heat/mass transfer. Most of the results discussed were obtained by finite volume CFD simulations concerning heat transfer in Membrane Distillation or mass transfer in Electrodialysis and Reverse Electrodialysis, but many of the conclusions apply also to different processes involving geometrically complex channels

  16. The influence of propofol, remifentanil and lidocaine on the tone of human bronchial smooth muscle.

    Science.gov (United States)

    Rogliani, Paola; Calzetta, Luigino; Rendina, Erino A; Massullo, Domenico; Dauri, Mario; Rinaldi, Barbara; Capuano, Annalisa; Matera, Maria Gabriella

    2013-06-01

    Bronchoscopy is generally a safe procedure, but the induction of anaesthesia can induce bronchospasm. Consequently we investigated the influence of propofol, remifentanil and lidocaine on the tone of the human bronchial smooth muscle. The influence of propofol, remifentanil and lidocaine on the contractile response of human bronchial smooth muscle to electrical field stimulation (EFS) has been evaluated. The role of capsaicin-sensitive sensory nerves and of inducible nitric oxide synthase has also been assessed. Furthermore, the interaction between these three dugs has been measured by Bliss Independence (BI) theory. Statistical significance (P < 0.05) was assessed by Student's t test or ANOVA. Propofol (1.3 μg ml(-1)) and lidocaine (1 mg ml(-1)) reduced the baseline tone of bronchial rings (-14.45 ± 4.53% and -33.40 ± 1.07%, respectively, P < 0.05), whereas remifentanil had not such effect. Aminoguanidine prevented the relaxant effect of propofol. Propofol did not alter the bronchial contractile response to EFS following 30 min of treatment, whereas remifentanil enhanced the bronchial tension (133.83 ± 9.38%, control 101.93 ± 6.82%, P < 0.05 P < 0.05) and lidocaine completely abolished the contractility at 1 mg ml(-1) (P < 0.05). The desensitization of capsaicin-sensitive sensory nerves normalized the hyperresponsiveness induced by remifentanil (-26.77 ± 1.68%, P < 0.05). Significant BI antagonism (P < 0.001) was detected for propofol and lidocaine on the bronchial hyperresponsiveness induced by remifentanil. Propofol and remifentanil may be used safely for bronchoscopy, although remifentanil should be associated with propofol or lidocaine to prevent the potential opioid-mediated bronchospasm. Copyright © 2013 Elsevier Ltd. All rights reserved.

  17. The influence of gap to the mass flux

    International Nuclear Information System (INIS)

    Kim, S. K.; Kang, C. H.; Hwang, Y. S.

    2000-01-01

    It was known that the release of gap is very important for I-129, Cs, which have high solubility. According to the disposal concept of spent fuel, there is a little gap between fuel rods and a canister. There is a concept that this gap may be filled with sand or beads, but it is impossible to perfectly fill for this gap, so the gap is one of important parameter in release mechanism. In this paper, the influence of gap was carried out. Gap volume have a little influence in the early stage(within a year), but there is not to significantly affect after 1 year. We have to consider the influence of filling material in canister such as cast iron, which have not considered on this paper

  18. A model of social influence on body mass index.

    Science.gov (United States)

    Hammond, Ross A; Ornstein, Joseph T

    2014-12-01

    In this paper, we develop an agent-based model of social influence on body weight. The model's assumptions are grounded in theory and evidence from physiology, social psychology, and behavioral science, and its outcomes are tested against longitudinal data from American youth. We discuss the implementation of the model, the insights it generates, and its implications for public health policy. By explicating a well-grounded dynamic mechanism, our analysis helps clarify important dependencies for both efforts to leverage social influence for obesity intervention and efforts to interpret clustering of BMI in networks. © 2014 New York Academy of Sciences.

  19. Mild Dehydration Does Not Influence Performance Or Skeletal Muscle Metabolism During Simulated Ice Hockey Exercise In Men.

    Science.gov (United States)

    Palmer, Matthew S; Heigenhauser, George J F; Duong, MyLinh; Spriet, Lawrence L

    2017-04-01

    This study determined whether mild dehydration influenced skeletal muscle glycogen use, core temperature or performance during high-intensity, intermittent cycle-based exercise in ice hockey players vs. staying hydrated with water. Eight males (21.6 ± 0.4 yr, 183.5 ± 1.6 cm, 83.9 ± 3.7 kg, 50.2 ± 1.9 ml·kg -1 ·min -1 ) performed two trials separated by 7 days. The protocol consisted of 3 periods (P) containing 10 × 45-s cycling bouts at ~133% VO 2max , followed by 135 s of passive rest. Subjects drank no fluid and dehydrated during the protocol (NF), or maintained body mass by drinking WATER. Muscle biopsies were taken at rest, immediately before and after P3. Subjects were mildly dehydrated (-1.8% BM) at the end of P3 in the NF trial. There were no differences between the NF and WATER trials for glycogen use (P1+P2; 350.1 ± 31.9 vs. 413.2 ± 33.2, P3; 103.5 ± 16.2 vs. 131.5 ± 18.9 mmol·kg dm -1 ), core temperature (P1; 37.8 ± 0.1 vs. 37.7 ± 0.1, P2; 38.2 ± 0.1 vs. 38.1 ± 0.1, P3; 38.3 ± 0.1 vs. 38.2 ± 0.1 °C) or performance (P1; 156.3 ± 7.8 vs. 154.4 ± 8.2, P2; 150.5 ± 7.8 vs. 152.4 ± 8.3, P3; 144.1 ± 8.7 vs. 148.4 ± 8.7 kJ). This study demonstrated that typical dehydration experienced by ice hockey players (~1.8% BM loss), did not affect glycogen use, core temperature, or voluntary performance vs. staying hydrated by ingesting water during a cycle-based simulation of ice hockey exercise in a laboratory environment.

  20. Pre- and post-operative evaluation of ventricular function, muscle mass and valve morphology by MR tomography in Ebstein's anomaly

    International Nuclear Information System (INIS)

    Gutberlet, M.; Oellinger, H.; Amthauer, H.; Hoffmann, T.; Felix, R.; Ewert, P.; Nagdyman, N.; Lange, P.; Hetzer, R.

    2000-01-01

    Purpose: To evaluate the value of MRT with spin echo (SE) and CINE gradient echo (GE) sequences for the pre- and postoperative assessment of patients with Ebstein's anomaly. Methods: Twelve patients within the ages of four to 49 years (mean 22±12 years) were examined pre- (n=5) or postoperatively (n=7) after tricuspid valve reconstruction with a 1.5 T scanner. For the anatomical assessment, an ECG-gated transverse SE-sequence, for the assessment of valve morphology and function as well as for volumetry a CINE GE-sequence with retrospective gating was used. With the use of the multislice-multiphase technique, after summing up the manually outlined epi- and endocardial areas, endsystolic (ESV) and enddiastolic volumes (EDV), ejection fraction (EF), stroke volume (SV), and muscle mass (MM) were calculated for both ventricles. Results: The differentiation of the displaced parts of the tricuspid valve (TV) was insufficient with static SE, but was possible in all patients with CINE-MRT. Like in Doppler echocardiography, a qualitative assessment of tricuspid insufficiency was possible in CINE-MRT, the mean incompetence grade preoperative was 1.8 (±0.8), postoperative 0.7 (±0.5). The mean RV-EF in the preoperative group was 41.8% (±6.4), in the postoperative group 47.9% (±10.6), the mean LV-EF preoperative 47.4% (±8.5%), postoperative 63,0% (±9.4). Conclusion: CINE-MRT should rather be used than SE for the assessment of valve morphology. EF, muscle mass and tricuspid incompetence can also be calculated pre- and postoperative with CINE-MRT. (orig.) [de

  1. Associations of dietary patterns with bone mass, muscle strength and balance in a cohort of Australian middle-aged women.

    Science.gov (United States)

    Wu, Feitong; Wills, Karen; Laslett, Laura L; Oldenburg, Brian; Jones, Graeme; Winzenberg, Tania

    2017-10-01

    Influences of dietary patterns on musculoskeletal health are poorly understood in middle-aged women. This cross-sectional analysis from a cohort of 347 women (aged 36-57 years) aimed to examine associations between dietary patterns and musculoskeletal health outcomes in middle-aged women. Diet was measured by the Cancer Council of Victoria FFQ. Total body bone mineral content (TB BMC), femoral neck and lumbar spine bone density (dual-energy X-ray absorptiometry), lower limbs muscle strength (LMS) and balance tests (timed up and go test, step test, functional reach test (FRT) and lateral reach test) were also measured. Exploratory factor analysis was used to identify dietary patterns and scores for each pattern generated using factor loadings with absolute values ≥0·20. Associations between food pattern scores and musculoskeletal outcomes were assessed using multivariable linear regression. Three dietary patterns were identified: 'Healthy' (high consumption of a plant-based diet - vegetables, legumes, fruit, tomatoes, nuts, snacks, garlic, whole grains and low intake of high-fat dairy products), 'high protein, high fat' (red meats, poultry, processed meats, potatoes, cruciferous and dark-yellow vegetables, fish, chips, spirits and high-fat dairy products) and 'Processed foods' (high intakes of meat pies, hamburgers, beer, sweets, fruit juice, processed meats, snacks, spirits, pizza and low intake of cruciferous vegetables). After adjustment for confounders, Healthy pattern was positively associated with LMS, whereas Processed foods pattern was inversely associated with TB BMC and FRT. The associations were not significant after accounting for multiple comparisons. There were no associations with any other outcomes. These results suggest that maintaining a healthy diet could contribute to bone acquisition, muscle strength and balance in adult life. However, while they provide some support for further investigating dietary strategies for prevention of age

  2. THE INFLUENCE OF EXTERNAL PERTURBATIONS ON RUNNING KINEMATICS AND MUSCLE ACTIVITY BEFORE AND AFTER ACCOMMODATION

    Directory of Open Access Journals (Sweden)

    Anita Haudum

    2012-12-01

    Full Text Available In the current study, the running pattern of the lower extremity was examined while being perturbed through tubes attached between the ankles and the lower back to analyze influences on the running pattern variability before and after a varied running intervention. 3D-kinematics, joint coupling and electromyography (EMG, as well as their variability, were analyzed in ten healthy male participants during treadmill running (10.5 km·h-1. Pre- and post-tests each consisted of 2 x 30 min treadmill running (one with and one without tubes. The results showed major acute effects on EMG and kinematics, as well as joint coordination variability, due to the constraints (p < 0.05. After the intervention, a process of normalization of most kinematic and EMG parameters occurred; however, EMG variability, kinematic variability and joint coordination variability were reduced during tube running below normal running level (p < 0.05. The findings further indicate rapid kinematic adaptations while muscle activity appears to require longer practice to adapt. The constraint serves to acutely increase variability, but may lead to reduced variability when applied for a longer period of time

  3. Influences of forest usage on the remainder mass and soil

    Directory of Open Access Journals (Sweden)

    Alexey Rosabal Quintana

    2017-12-01

    Full Text Available The work was carried out in the handling area "Los Números" belonging to the mountainous ecosystem of the Silvicole Unit Guisa, with the objective of determining the damages to the soil and the remainder mass to the forest usage to give execution to this objective the transcept method was used where punctual observations for every 20 meters were made,, parcels rose and a striped florístic was elaborated from that of a total of 3 302 trees, they were downed 339 which caused the death of 1 313, causing that 7.7% of the usage area was impacted by hints or clearings.

  4. The influence of low temperature, type of muscle and electrical stimulation on the course of rigor mortis, ageing and tenderness of beef muscles.

    Science.gov (United States)

    Olsson, U; Hertzman, C; Tornberg, E

    1994-01-01

    The course of rigor mortis, ageing and tenderness have been evaluated for two beef muscles, M. semimembranosus (SM) and M. longissimus dorsi (LD), when entering rigor at constant temperatures in the cold-shortening region (1, 4, 7 and 10°C). The influence of electrical stimulation (ES) was also examined. Post-mortem changes were registered by shortening and isometric tension and by following the decline of pH, ATP and creatine phosphate. The effect of ageing on tenderness was recorded by measuring shear-force (2, 8 and 15 days post mortem) and the sensory properties were assessed 15 days post mortem. It was found that shortening increased with decreasing temperature, resulting in decreased tenderness. Tenderness for LD, but not for SM, was improved by ES at 1 and 4°C, whereas ES did not give rise to any decrease in the degree of shortening during rigor mortis development. This suggests that ES influences tenderization more than it prevents cold-shortening. The samples with a pre-rigor mortis temperature of 1°C could not be tenderized, when stored up to 15 days, whereas this was the case for the muscles entering rigor mortis at the other higher temperatures. The results show that under the conditions used in this study, the course of rigor mortis is more important for the ultimate tenderness than the course of ageing. Copyright © 1994. Published by Elsevier Ltd.

  5. Impaired Bronchoprotection Is Not Induced by Increased Smooth Muscle Mass in Chronic Treatment In Vivo with Formoterol in Asthmatic Mouse Model

    Directory of Open Access Journals (Sweden)

    W Luo

    2014-09-01

    Full Text Available Objective: Inhaling β2-adrenoceptor agonist is first-line asthma treatment, which is used for both acute relief and prevention of bronchoconstriction. However, chronic use of β-agonists results in impaired bronchoprotection and increasing occurrences of severe asthma exacerbation, even death in clinical practice. The mechanism of β-adrenoceptor hyposensitivity has not been thoroughly elucidated thus far. Bronchial smooth muscle contraction induces airway narrowing and also mediates airway inflammation. Moreover, bronchial smooth muscle mass significantly increases in asthmatics. We aimed to establish an asthmatic model that demonstrated that formoterol induced impaired bronchoprotection and to see whether increased smooth muscle mass played a role in it. Methods: We combined routine allergen challenging (seven weeks with repeated application of formoterol, formoterol plus budesonide or physiological saline in allergen-sensitized BALB/c mouse. The bronchoprotection mediated by β-agonist was measured in five consecutive weeks. Smooth muscle mass was shown by morphometric analysis, and α-actin expression was detected by western blot. Results: The trend of bronchoprotection was wavy in drug interventional groups, which initially increased and then decreased. Chronic treatment with formoterol significantly impaired bronchoprotection. According to the morphometric analysis and α-actin expression, no significant difference was detected in smooth muscle mass in all groups. Conclusion: This experiment successfully established that a chronic asthmatic mouse model, which manifested typical features of asthmatic patients, with chronic use of formoterol, results in a loss of bronchoprotection. No significant difference was detected in smooth muscle mass in all groups, which implied some subcellular signalling changes may be the key points.

  6. The influence of simulated transversus abdominis muscle force on sacroiliac joint flexibility during asymmetric moment application to the pelvis.

    Science.gov (United States)

    Gnat, Rafael; Spoor, Kees; Pool-Goudzwaard, Annelies

    2015-10-01

    The role of so-called local muscle system in motor control of the lower back and pelvis is a subject of ongoing debate. Prevailing beliefs in stabilizing function of this system were recently challenged. This study investigated the impact of in vitro simulated force of transversely oriented fibres of the transversus abdominis muscle (a part of the local system) on flexibility of the sacroiliac joint during asymmetric moment application to the pelvis. In 8 embalmed specimens an incremental moment was applied in the sagittal plane to one innominate with respect to the fixed contralateral innominate. Ranges of motion of the sacroiliac joint were recorded using the Vicon Motion Capture System. Load-deformation curves were plotted and flexibility of the sacroiliac joint was calculated separately for anterior and posterior rotations of the innominate, with and without simulated muscle force. Flexibility of the sacroiliac joint was significantly bigger during anterior rotation of the innominate, as compared to posterior rotation (Anova Psacroiliac joint was demonstrated. Earlier hypotheses suggesting a stiffening influence of this muscle on the pelvis cannot be confirmed. Consistent with previous findings smaller flexibility of the joint recorded during posterior rotation of the innominate may be of clinical importance for physio- and manual therapists. However, major limitations of the study should be acknowledged: in vitro conditions and simulation of only solitary muscle force. Copyright © 2015 Elsevier Ltd. All rights reserved.

  7. A pilot study on the influence of exercising on unstable training machine on balance control and trunk muscles activity.

    Science.gov (United States)

    Domeika, Aurelijus; Aleknaite-Dambrauskiene, Ieva; Poskaitis, Vytautas; Zaveckas, Vidmantas; Grigas, Vytautas; Zvironiene, Ausra

    2018-05-16

    The main position of the working population is becoming sitting. Immobile prolonged sedentary time may cause negative effects including reduced intervertebral discs nutrition. Main ways of mitigating them are regular position changes and exercising. To evaluate influence of the short term training on unstable training machine on balance control and trunk muscles activity in patients with lower back pain. Participants (n=16) experiencing lower back pain were trained on an unstable sculling machine "Rehabili". Their balance tested by (Biodex Balance System) and rectus abdominis, externus oblique, transverse abdominis, multifidus and erector spine muscles activity (measured by surface electromyography) while sitting and standing with usual and aligned body postures both before and after six weeks of training (three 15 minutes sessions per week) were compared in between. Balance control improved after the training program. Besides, more symmetrical activation of both sides rectus and transversus abdominis muscles, as well as increased transversus abdominis muscle activation of 19% (p< 0.05), were observed. Six weeks short sessions training on unstable training machine improved balance control and increased trunk muscles activity especially in aligned body posture when standing or sitting on unstable surface.

  8. Purification and Crystallization of Murine Myostatin: A Negative Regulator of Muscle Mass

    Science.gov (United States)

    Hong, Young S.; Adamek, Daniel; Bridge, Kristi; Malone, Christine C.; Young, Ronald B.; Miller, Teresa; Karr, Laurel

    2004-01-01

    Myostatin (MSTN) has been crystallized and its preliminary X-ray diffraction data were collected. MSTN is a negative regulator of muscle growt/differentiation and suppressor of fat accumulation. It is a member of TGF-b family of proteins. Like other members of this family, the regulation of MSTN is critically tied to its process of maturation. This process involves the formation of a homodimer followed by two proteolytic steps. The first proteolytic cleavage produces a species where the n-terminal portion of the dimer is covalently separated from, but remains non-covalently bound to, the c-terminal, functional, portion of the protein. The protein is activated upon removal of the n-terminal "pro-segment" by a second n-terminal proteolytic cut by BMP-1 in vivo, or by acid treatment in vitro. Understanding the structural nature and physical interactions involved in these regulatory processes is the objective of our studies. Murine MSTN was purified from culture media of genetically engineered Chinese Hamster Ovary cells by multicolumn purification process and crystallized using the vapor diffusion method.

  9. The Influence of Coronal Mass Ejections on the Mass-loss Rates of Hot-Jupiters

    Energy Technology Data Exchange (ETDEWEB)

    Cherenkov, A.; Bisikalo, D. [Institute of Astronomy of the Russian Academy of Sciences, 48 Pyatnitskaya St. 119017, Moscow (Russian Federation); Fossati, L.; Möstl, C., E-mail: bisikalo@inasan.ru [Space Research Institute, Austrian Academy of Sciences, Schmiedlstrasse 6, A-8042 Graz (Austria)

    2017-09-01

    Hot-Jupiters are subject to extreme radiation and plasma flows coming from their host stars. Past ultraviolet Hubble Space Telescope observations, supported by hydrodynamic models, confirmed that these factors lead to the formation of an extended envelope, part of which lies beyond the Roche lobe. We use gas-dynamic simulations to study the impact of time variations in the parameters of the stellar wind, namely that of coronal mass ejections (CMEs), on the envelope of the typical hot-Jupiter HD 209458b. We consider three CMEs characterized by different velocities and densities, taking their parameters from typical CMEs observed for the Sun. The perturbations in the ram-pressure of the stellar wind during the passage of each CME tear off most of the envelope that is located beyond the Roche lobe. This leads to a substantial increase of the mass-loss rates during the interaction with the CME. We find that the mass lost by the planet during the whole crossing of a CME is of ≈10{sup 15} g, regardless of the CME taken into consideration. We also find that over the course of 1 Gyr, the mass lost by the planet because of CME impacts is comparable to that lost because of high-energy stellar irradiation.

  10. The Influence of Nutrition, Sex and Slaughter Age on Characteristics of Pectoralis Major Muscle at Broiler Chickens Ross-308

    Directory of Open Access Journals (Sweden)

    Adela Marcu

    2014-05-01

    Full Text Available In this paper was studied the effect of dietary energy and protein levels on characteristics of pectoralis major (P. major muscle at broiler chickens, which were sacrificed at 35 and 42 days old. The genetic material was represented by broiler chickens that belonged to the „Ross-308” hybrid, with two groups (LC-control group and LE experimental group. During the growth periods (starter, growing and finishing they have received compound feed ad libitum, with different energy and protein levels (LC-conforming to recommendations of Aviagen Company; LE-higher with 10%. After slaughter, from each group were sampled breast muscles (five per sex and for P. major were determined: the weight, pH value, the thickness of myocytes (fiber diameter, cross-sectional area of fibers. At the LE group, high levels of dietary proteins and energy has significantly influenced pH value and the thickness of myocytes in the P. major muscle, as compared with LC. The sex and slaughter age have significantly influenced the fibers diameter from P. major muscle, that were thicker at female chickens, as compared with male chickens and at 42 days age vs. 35 days.

  11. Visualization of dynamic change in contraction-induced lipid composition in mouse skeletal muscle by matrix-assisted laser desorption/ionization imaging mass spectrometry.

    Science.gov (United States)

    Goto-Inoue, Naoko; Manabe, Yasuko; Miyatake, Shouta; Ogino, Shinya; Morishita, Ai; Hayasaka, Takahiro; Masaki, Noritaka; Setou, Mitsutoshi; Fujii, Nobuharu L

    2012-06-01

    Lipids in skeletal muscle play a fundamental role both in normal muscle metabolism and in disease states. Skeletal muscle lipid accumulation is associated with several chronic metabolic disorders, including obesity, insulin resistance, and type 2 diabetes. However, it is poorly understood whether the lipid composition of skeletal muscle changes by contraction, due to the complexity of lipid molecular species. In this study, we used matrix-assisted laser desorption/ionization imaging mass spectrometry (MALDI-IMS) to investigate changes in skeletal muscle lipid composition induced by contraction. We successfully observed the reduction of diacylglycerol and triacylglycerol, which are generally associated with muscle contraction. Interestingly, we found the accumulation of some saturated and mono-unsaturated fatty acids and poly-unsaturated fatty acids containing phosphatidylcholine in contracted muscles. Moreover, the distributions of several types of lipid were changed by contraction. Our results show that changes in the lipid amount, lipid composition, and energy metabolic activity can be evaluated in each local spot of cells and tissues at the same time using MALDI-IMS. In conclusion, MALDI-IMS is a powerful tool for studying lipid changes associated with contractions.

  12. Metabolomic Analysis of Oxidative and Glycolytic Skeletal Muscles by Matrix-Assisted Laser Desorption/IonizationMass Spectrometric Imaging (MALDI MSI)

    Science.gov (United States)

    Tsai, Yu-Hsuan; Garrett, Timothy J.; Carter, Christy S.; Yost, Richard A.

    2015-06-01

    Skeletal muscles are composed of heterogeneous muscle fibers that have different physiological, morphological, biochemical, and histological characteristics. In this work, skeletal muscles extensor digitorum longus, soleus, and whole gastrocnemius were analyzed by matrix-assisted laser desorption/ionization mass spectrometry to characterize small molecule metabolites of oxidative and glycolytic muscle fiber types as well as to visualize biomarker localization. Multivariate data analysis such as principal component analysis (PCA) and partial least squares discriminant analysis (PLS-DA) were performed to extract significant features. Different metabolic fingerprints were observed from oxidative and glycolytic fibers. Higher abundances of biomolecules such as antioxidant anserine as well as acylcarnitines were observed in the glycolytic fibers, whereas taurine and some nucleotides were found to be localized in the oxidative fibers.

  13. Influence of Isometric Exercise Training on Quadriceps Muscle Architecture and Strength in Obese Subjects with Knee Osteoarthritis

    Directory of Open Access Journals (Sweden)

    Waleed S Mahmoud

    2017-03-01

    Full Text Available Obese individuals have reduced quadriceps muscle strength relative to body mass that may increase the rate of progression of knee osteoarthritis (OA. The purpose of this study was to evaluate the effects of isometric exercise training on quadriceps muscle architecture and strength in obese subjects with knee osteoarthritis. Methods: Fortyfour obese male subjects aged 40–65 years diagnosed with knee osteoarthritis were randomly assigned into group A (n=32 and group B (n=12. Group A subjects performed a 12-week isometric exercise program. Group B subjects did not participate in any exercise program and maintained their ordinary activities for the same period. Both groups received the same conventional physical therapy program including hot packs and therapeutic ultrasonic. Muscle thickness, pennation angles and fascicle length of the vastus lateralis (VL muscle of the affected knee were measured at rest by B-mode ultrasonography. Maximal voluntary isometric knee extension torque (MVIC of the affected knee was measured using an isokinetic dynamometer. Knee pain and function were evaluated using visual analogue pain scale (VAS and Western Ontario and McMaster Universities Arthritis Index (WOMAC. All variables were evaluated before and the end of the intervention period for both groups. Results: at the end of the program, group A subjects showed significant improvements compared with group B subjects regarding MVIC and muscle architecture parameters (p<0.05. Also, there was significant improvement in post-test VAS and WOMAC scores in group A subjects compared to group B subjects (p<0.05. Conclusion: A 12-week quadriceps isometric training program improves knee pain and quadriceps muscle strength and architecture in obese subjects with knee OA. These results indicate that isometric training should be regarded as a proper exercise intervention for obese patients with knee OA.

  14. Protein-containing nutrient supplementation following strength training enhances the effect on muscle mass, strength, and bone formation in postmenopausal women

    DEFF Research Database (Denmark)

    Holm, Lars; Olesen, Jens L; Matsumoto, Keitaro

    2008-01-01

    .0 +/- 1.4%); nutrient group: 0.953 +/- 0.051 to 0.978 +/- 0.043 g/mm(3) (3.8 +/- 3.4%)] when adjusted for age, body mass index, and BMD at inclusion. Bone formation displayed an interaction (P increased osteocalcin at 24 wk in the nutrient group. In conclusion, we report...... that nutrient supplementation results in superior improvements in muscle mass, muscle strength, femoral neck BMD, and bone formation during 24 wk of strength training. The observed differences following such a short intervention emphasize the significance of postexercise nutrient supply on musculoskeletal......We evaluated the response of various muscle and bone adaptation parameters with 24 wk of strength training in healthy, early postmenopausal women when a nutrient supplement (protein, carbohydrate, calcium, and vitamin D) or a placebo supplement (a minimum of energy) was ingested immediately...

  15. Protein-containing nutrient supplementation following strength training enhances the effect on muscle mass, strength, and bone formation in postmenopausal women

    DEFF Research Database (Denmark)

    Holm, Lars; Olesen, J.L.; Matsumoto, K.

    2008-01-01

    .4%); nutrient group: 0.953 ± 0.051 to 0.978 ± 0.043 g/mm3 (3.8 ± 3.4%)] when adjusted for age, body mass index, and BMD at inclusion. Bone formation displayed an interaction (P increased osteocalcin at 24 wk in the nutrient group. In conclusion, we report that nutrient supplementation...... results in superior improvements in muscle mass, muscle strength, femoral neck BMD, and bone formation during 24 wk of strength training. The observed differences following such a short intervention emphasize the significance of postexercise nutrient supply on musculoskeletal maintenance.......We evaluated the response of various muscle and bone adaptation parameters with 24 wk of strength training in healthy, early postmenopausal women when a nutrient supplement (protein, carbohydrate, calcium, and vitamin D) or a placebo supplement (a minimum of energy) was ingested immediately...

  16. Dual-energy X-ray absorptiometry is a valid tool for assessing skeletal muscle mass in older women.

    Science.gov (United States)

    Chen, Zhao; Wang, ZiMian; Lohman, Timothy; Heymsfield, Steven B; Outwater, Eric; Nicholas, Jennifer S; Bassford, Tamsen; LaCroix, Andrea; Sherrill, Duane; Punyanitya, Mark; Wu, Guanglin; Going, Scott

    2007-12-01

    Assessing skeletal muscle mass (SMM) is critical in studying and detecting sarcopenia. Direct measurements by MRI or computerized tomography are expensive or high in radiation exposure. Dual-energy X-ray absorptiometry (DXA) is promising for body composition assessments, but the validity of DXA for predicting SMM in the elderly is still under investigation. The objective of this study was to assess the relationship between DXA-derived measurements of lean soft tissue mass (LSTM) and SMM in older women. Study participants were postmenopausal women (n = 101) recruited in southern Arizona. Total and regional body composition was measured using MRI and DXA (QDR4500w). The participants' mean age was 70.7 +/- 6.4 y and their mean BMI was 27.4 +/- 5.1 kg/m2. DXA-derived LSTM was highly correlated with MRI-derived SMM for the whole body (r = 0.94; P LSTM assessments for the leg region but not for the total body. In conclusion, although the relationships between DXA measures and MRI-derived SMM vary by region of interest, the overall prediction of SMM by DXA is excellent. We conclude that DXA is a reliable method for cross-sectional assessments of SMM in older women.

  17. Low skeletal muscle mass is a predictive factor for chemotherapy dose-limiting toxicity in patients with locally advanced head and neck cancer

    NARCIS (Netherlands)

    Wendrich, Anne W; Swartz, Justin E; Bril, Sandra I; Wegner, Inge; de Graeff, Alexander; Smid, Ernst J; de Bree, Remco; Pothen, Ajit J

    OBJECTIVES: Low skeletal muscle mass (SMM) or sarcopenia is emerging as an adverse prognostic factor for chemotherapy dose-limiting toxicity (CLDT) and survival in cancer patients. Our aim was to determine the impact of low SMM on CDLT in patients with locally advanced head and neck squamous cell

  18. Efficacy of whey protein supplementation on resistance exercise-induced changes in muscle strength, lean mass, and function in mobility-limited older adults

    Science.gov (United States)

    Whey protein supplementation may augment resistance exercise-induced increases in muscle strength and mass. Further studies are required to determine whether this effect extends to functionally compromised older adults. The objectives of the study were to compare the effects of whey protein concent...

  19. Effects of high protein diets on fat-free mass and muscle protein synthesis following weight loss: a randomized controlled trial

    Science.gov (United States)

    Context: The benefits of high protein diets for sparing lean body mass and sustaining skeletal muscle protein metabolism during short-term weight loss in normal-weight adults are not well described. Objective: Determine the effects of varying levels of dietary protein intake on body compos...

  20. The Impact of dietary protein or amino acid supplementation on muscle mass and strength in elderly people : individual participant data and meta-analysis of RCT's

    NARCIS (Netherlands)

    Tieland, M.; Franssen, R.; Dullemeijer, C.; van Dronkelaar, C; Kyung Kim, H.; Ispoglou, T; Zhu, K.; Prince, R. L.; van Loon, L. J. C.; de Groot, Lisette C. P. G. M.

    2017-01-01

    OBJECTIVES: Increasing protein or amino acid intake has been promoted as a promising strategy to increase muscle mass and strength in elderly people, however, long-term intervention studies show inconsistent findings. Therefore, we aim to determine the impact of protein or amino acid supplementation

  1. Influence of Endurance Training During Childhood on Total Hemoglobin Mass.

    Science.gov (United States)

    Prommer, Nicole; Wachsmuth, Nadine; Thieme, Ina; Wachsmuth, Christian; Mancera-Soto, Erica M; Hohmann, Andreas; Schmidt, Walter F J

    2018-01-01

    Elite endurance athletes are characterized by markedly increased hemoglobin mass (Hbmass). It has been hypothesized that this adaptation may occur as a response to training at a very young age. Therefore, the aim of this study was to monitor changes in Hbmass in children aged 8-14 years following systematic endurance training. In the first study, Hbmass, VO2max, and lean body mass (LBM) were measured in 17 endurance-trained children (13 boys and 4 girls; aged 9.7 ± 1.3 years; training history 1.5±1.8 years; training volume 3.5 ± 1.6 h) twice a year for up to 3.5 years. The same parameters were measured once in a control group of 18 age-matched untrained children. Hbmass and blood volume (BV) were measured using the optimized CO-rebreathing technique, VO2max by an incremental test on a treadmill, and LBM by skin-fold measurements. In the second pilot study, the same parameters were measured in 9 young soccer athletes (aged 7.8 ± 0.2 years), and results were assessed in relation to soccer performance 2.5 years later. The increase in mean Hbmass during the period of study was 50% which was closely related to changes in LBM ( r = 0.959). A significant impact of endurance training on Hbmass was observed in athletes exercising more than 4 h/week [+25.4 g compared to the group with low training volume (LBM (11.4 g·kg -1 LBM) and overlapped with the effects of age. A strong relationship was present between absolute Hbmass and VO2max ( r = 0.939), showing that an increase of 1 g hemoglobin increases VO2max by 3.6 ml·min -1 . Study 2 showed a positive correlation between Hbmass and soccer performance 2.5 years later at age 10.3 ± 0.3 years ( r = 0.627, p = 0.035). In conclusion, children with a weekly training volume of more than 4 h show a 7% higher Hbmass than untrained children. Although this training effect is significant and independent of changes in LBM, the major factor driving the increase in Hbmass is still LBM.

  2. Modeling the influence of coupled mass transfer processes on mass flux downgradient of heterogeneous DNAPL source zones.

    Science.gov (United States)

    Yang, Lurong; Wang, Xinyu; Mendoza-Sanchez, Itza; Abriola, Linda M

    2018-04-01

    Sequestered mass in low permeability zones has been increasingly recognized as an important source of organic chemical contamination that acts to sustain downgradient plume concentrations above regulated levels. However, few modeling studies have investigated the influence of this sequestered mass and associated (coupled) mass transfer processes on plume persistence in complex dense nonaqueous phase liquid (DNAPL) source zones. This paper employs a multiphase flow and transport simulator (a modified version of the modular transport simulator MT3DMS) to explore the two- and three-dimensional evolution of source zone mass distribution and near-source plume persistence for two ensembles of highly heterogeneous DNAPL source zone realizations. Simulations reveal the strong influence of subsurface heterogeneity on the complexity of DNAPL and sequestered (immobile/sorbed) mass distribution. Small zones of entrapped DNAPL are shown to serve as a persistent source of low concentration plumes, difficult to distinguish from other (sorbed and immobile dissolved) sequestered mass sources. Results suggest that the presence of DNAPL tends to control plume longevity in the near-source area; for the examined scenarios, a substantial fraction (43.3-99.2%) of plume life was sustained by DNAPL dissolution processes. The presence of sorptive media and the extent of sorption non-ideality are shown to greatly affect predictions of near-source plume persistence following DNAPL depletion, with plume persistence varying one to two orders of magnitude with the selected sorption model. Results demonstrate the importance of sorption-controlled back diffusion from low permeability zones and reveal the importance of selecting the appropriate sorption model for accurate prediction of plume longevity. Large discrepancies for both DNAPL depletion time and plume longevity were observed between 2-D and 3-D model simulations. Differences between 2- and 3-D predictions increased in the presence of

  3. Modeling the influence of coupled mass transfer processes on mass flux downgradient of heterogeneous DNAPL source zones

    Science.gov (United States)

    Yang, Lurong; Wang, Xinyu; Mendoza-Sanchez, Itza; Abriola, Linda M.

    2018-04-01

    Sequestered mass in low permeability zones has been increasingly recognized as an important source of organic chemical contamination that acts to sustain downgradient plume concentrations above regulated levels. However, few modeling studies have investigated the influence of this sequestered mass and associated (coupled) mass transfer processes on plume persistence in complex dense nonaqueous phase liquid (DNAPL) source zones. This paper employs a multiphase flow and transport simulator (a modified version of the modular transport simulator MT3DMS) to explore the two- and three-dimensional evolution of source zone mass distribution and near-source plume persistence for two ensembles of highly heterogeneous DNAPL source zone realizations. Simulations reveal the strong influence of subsurface heterogeneity on the complexity of DNAPL and sequestered (immobile/sorbed) mass distribution. Small zones of entrapped DNAPL are shown to serve as a persistent source of low concentration plumes, difficult to distinguish from other (sorbed and immobile dissolved) sequestered mass sources. Results suggest that the presence of DNAPL tends to control plume longevity in the near-source area; for the examined scenarios, a substantial fraction (43.3-99.2%) of plume life was sustained by DNAPL dissolution processes. The presence of sorptive media and the extent of sorption non-ideality are shown to greatly affect predictions of near-source plume persistence following DNAPL depletion, with plume persistence varying one to two orders of magnitude with the selected sorption model. Results demonstrate the importance of sorption-controlled back diffusion from low permeability zones and reveal the importance of selecting the appropriate sorption model for accurate prediction of plume longevity. Large discrepancies for both DNAPL depletion time and plume longevity were observed between 2-D and 3-D model simulations. Differences between 2- and 3-D predictions increased in the presence of

  4. Lifelong exercise and locally produced insulin-like growth factor-1 (IGF-1) have a modest influence on reducing age-related muscle wasting in mice.

    Science.gov (United States)

    McMahon, C D; Chai, R; Radley-Crabb, H G; Watson, T; Matthews, K G; Sheard, P W; Soffe, Z; Grounds, M D; Shavlakadze, T

    2014-12-01

    The age-related loss of skeletal muscle mass and function is termed sarcopenia and has been attributed to a decline in concentrations of insulin-like growth factor-1 (IGF-1). We hypothesized that constitutively expressed IGF-1 within skeletal muscles with or without exercise would prevent sarcopenia. Male transgenic mice that overexpress IGF-1 Ea in skeletal muscles were compared with wild-type littermates. Four-month-old mice were assigned to be sedentary, or had access to free-running wheels, until 18 or 28 months of age. In wild-type mice, the mass of the quadriceps muscles was reduced at 28 months and exercise prevented such loss, without affecting the diameter of myofibers. Conversely, increased IGF-1 alone was ineffective, whereas the combination of exercise and IGF-1 was additive in maintaining the diameter of myofibers in the quadriceps muscles. For other muscles, the combination of IGF-1 and exercise was variable and either increased or decreased the mass at 18 months of age, but was ineffective thereafter. Despite an increase in the diameter of myofibers, grip strength was not improved. In conclusion, our data show that exercise and IGF-1 have a modest effect on reducing aged-related wasting of skeletal muscle, but that there is no improvement in muscle function when assessed by grip strength. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  5. Motor unit recruitment patterns 2: the influence of myoelectric intensity and muscle fascicle strain rate.

    Science.gov (United States)

    Hodson-Tole, Emma F; Wakeling, James M

    2008-06-01

    To effectively meet the force requirements of a given movement an appropriate number and combination of motor units must be recruited between and within muscles. Orderly recruitment of motor units has been shown to occur in a wide range of skeletal muscles, however, alternative strategies do occur. Faster motor units are better suited to developing force rapidly, and produce higher mechanical power with greater efficiency at faster shortening strain rates than slower motor units. As the frequency content of the myoelectric signal is related to the fibre type of the active motor units, we hypothesised that, in addition to an association between myoelectric frequency and intensity, there would be a significant association between muscle fascicle shortening strain rate and myoelectric frequency content. Myoelectric and sonomicrometric data were collected from the three ankle extensor muscles of the rat hind limb during walking and running. Myoelectric signals were analysed using wavelet transformation and principal component analysis to give a measure of the signal frequency content. Sonomicrometric signals were analysed to give measures of muscle fascicle strain and strain rate. The relationship between myoelectric frequency and both intensity and muscle fascicle strain rate was found to change across the time course of a stride, with differences also occurring in the strength of the associations between and within muscles. In addition to the orderly recruitment of motor units, a mechanical strategy of motor unit recruitment was therefore identified. Motor unit recruitment is therefore a multifactorial phenomenon, which is more complex than typically thought.

  6. Effects of Insect Protein Supplementation during Resistance Training on Changes in Muscle Mass and Strength in Young Men

    Directory of Open Access Journals (Sweden)

    Mathias T. Vangsoe

    2018-03-01

    Full Text Available During prolonged resistance training, protein supplementation is known to promote morphological changes; however, no previous training studies have tested the effect of insect protein isolate in a human trial. The aim of this study was to investigate the potential effect of insect protein as a dietary supplement to increase muscle hypertrophy and strength gains during prolonged resistance training in young men. Eighteen healthy young men performed resistance training four day/week for eight weeks. Subjects were block randomized into two groups consuming either an insect protein isolate or isocaloric carbohydrate supplementation within 1 h after training and pre-sleep on training days. Strength and body composition were measured before and after intervention to detect adaptions to the resistance training. Three-day weighed dietary records were completed before and during intervention. Fat- and bone- free mass (FBFM improved significantly in both groups (Mean (95% confidence interval (CI, control group (Con: (2.5 kg (1.5, 3.5 p < 0.01, protein group (Pro: (2.7 kg (1.6, 3.8 p < 0.01 from pre- to post-. Leg and bench press one repetition maximum (1 RM improved by Con: (42.0 kg (32.0, 52.0 p < 0.01 and (13.8 kg (10.3, 17.2 p < 0.01, Pro: (36.6 kg (27.3, 45.8 p < 0.01 and (8.1 kg (4.5, 11.8 p < 0.01, respectively. No significant differences in body composition and muscle strength improvements were found between groups. In young healthy men, insect protein supplementation did not improve adaptations to eight weeks of resistance training in comparison to carbohydrate supplementation. A high habitual protein intake in both Con and Pro may partly explain our observation of no superior effect of insect protein supplementation.

  7. Effect of pretreatment psoas muscle mass on survival for patients with unresectable pancreatic cancer undergoing systemic chemotherapy.

    Science.gov (United States)

    Ishii, Noriko; Iwata, Yoshinori; Nishikawa, Hiroki; Enomoto, Hirayuki; Aizawa, Nobuhiro; Ishii, Akio; Miyamoto, Yuho; Yuri, Yukihisa; Hasegawa, Kunihiro; Nakano, Chikage; Nishimura, Takashi; Yoh, Kazunori; Sakai, Yoshiyuki; Ikeda, Naoto; Takashima, Tomoyuki; Takata, Ryo; Iijima, Hiroko; Nishiguchi, Shuhei

    2017-11-01

    To the best of our knowledge, there are few previous studies that have investigated the effect of decreased skeletal muscle mass (DSMM) on survival in patients with unresectable advanced pancreatic cancer (APC) who are undergoing systemic chemotherapy. Thus, the present study aimed to investigate the impact of DSMM, as determined by the psoas muscle index (PMI) following computed tomography and prior to systemic chemotherapy, on the outcomes of patients with unresectable APC (n=61). The primary endpoint used was the overall survival (OS) rate. The OS rates in the PMI-High group (exceeds the median PMI value in each gender) were retrospectively compared with those in the PMI-Low group (below the median PMI value in each gender), and factors associated with OS were investigated using univariate and multivariate analyses. The study cohort included 31 male and 30 female patients with a median age of 72 years, 13 of whom were stage IVA, and 48 were stage IVB. The median PMI in males was 4.3 cm 2 /m 2 (range, 1.6-8.2 cm 2 /m 2 ), while that in females was 2.3 cm 2 /m 2 (range, 0.7-6.1 cm 2 /m 2 ). The proportion of patients with performance status 0 in the PMI-High group was significantly high, compared with that in the PMI-Low group [83.3% (25/30) vs. 58.1% (18/31); P=0.0486]. Body mass index in the PMI-High group was significantly higher compared with that in the PMI-Low group (P=0.0154). The 1-year cumulative survival rate was 43.3% in the PMI-High group and 12.9% in the PMI-Low group (P=0.0027). Following multivariate analysis, PMI (P=0.0036), prothrombin time (P=0.0044) and carbohydrate antigen 19-9 (P=0.0451) were identified to be significant predictors of OS. In conclusion, DSMM, as determined by the PMI, could be a significant predictor of prognosis in patients with unresectable APC who are receiving systemic chemotherapy.

  8. Eccentric Torque-Producing Capacity is Influenced by Muscle Length in Older Healthy Adults.

    Science.gov (United States)

    Melo, Ruth C; Takahashi, Anielle C M; Quitério, Robison J; Salvini, Tânia F; Catai, Aparecida M

    2016-01-01

    Considering the importance of muscle strength to functional capacity in the elderly, the study investigated the effects of age on isokinetic performance and torque production as a function of muscle length. Eleven younger (24.2 ± 2.9 years) and 16 older men (62.7 ± 2.5 years) were subjected to concentric and eccentric isokinetic knee extension/flexion at 60 and 120° · s(-1) through a functional range of motion. The older group presented lower peak torque (in newton-meters) than the young group for both isokinetic contraction types (age effect, p torque deficits in the older group were near 30 and 29% for concentric and eccentric contraction, respectively. Concentric peak torque was lower at 120° · s(-1) than at 60° · s(-1) for both groups (angular velocity effect, p torque was the only exercise tested that showed an interaction effect between age and muscle length (p torque responses to the muscle length between groups. Compared with the young group, the eccentric knee extension torque was 22-56% lower in the older group, with the deficits being lower in the shortened muscle length (22-27%) and higher (33-56%) in the stretched muscle length. In older men, the production of eccentric knee strength seems to be dependent on the muscle length. At more stretched positions, older subjects lose the capacity to generate eccentric knee extension torque. More studies are needed to assess the mechanisms involved in eccentric strength preservation with aging and its relationship with muscle length.

  9. Influence of changing occlusal support on jaw-closing muscle electromyographic activity in healthy men and women.

    Science.gov (United States)

    Wang, Mei-Qing; He, Jian-Jun; Wang, Kelun; Svensson, Peter

    2009-01-01

    To test whether changes in occlusal support differentially modulate masseter and anterior temporalis muscle electromyographic (EMG) activity during controlled maximal voluntary clenching. Forty-seven healthy subjects (32 M and 15 F, 22.9+/-1.3 years) were recruited. Cotton-rolls were used to modify the occlusal contact relations and were positioned on the right, left, or both sides, and either in the molar or premolar regions, i.e. six different occlusal combinations. Surface EMG activity was recorded bilaterally from the masseter and anterior temporalis area and normalized with respect to maximal voluntary clenching in the intercuspal position. Analysis of variance and the paired t-test were used to test the data. Normalized EMG activity was influenced by changes in cotton-roll modified occlusal support, and there were differences between muscles (pocclusal support was moved from the molar to the premolar region. When occlusal support was moved from bilateral to unilateral contacts, EMG activity in the balancing-side anterior temporalis muscle and in bilateral masseter muscles decreased. Unilateral clenching on the molars, but not on the premolars, was associated with lower EMG activity in the balancing-side masseter and always associated with lower EMG activity in the balancing-side anterior temporalis compared to the working side (pocclusal support, which may have implications for stability of the mandible during intense clenching.

  10. The total body mass of fatty acid ethyl esters in skeletal muscles following ethanol exposure greatly exceeds that found in the liver and the heart.

    Science.gov (United States)

    Salem, Raneem O; Laposata, Michael; Rajendram, Rajkumar; Cluette-Brown, Joanne E; Preedy, Victor R

    2006-01-01

    Skeletal muscle appears to be susceptible to chronic and acute excess alcohol intake, giving rise to alcoholic myopathy, a common disease among alcoholics. Fatty acid ethyl esters (FAEE), non-oxidative metabolites of ethanol, have been shown to be toxic to cells in vitro and in vivo. We hypothesized that accumulation of FAEE in skeletal muscle could contribute to the development of alcoholic myopathy. Male wistar rats were treated either with 75 mmol ethanol/kg body weight or saline, in the fed state or starved for 1 or 2 days before administration. Rats were thus divided into the following groups: fed-saline (n = 8); fed-ethanol (n = 8); starved 1 day, saline (n = 8); starved 1 day, ethanol (n = 9); starved 2 days, saline (n = 7); and starved 2 days, ethanol (n = 8). At the end of the incubation, skeletal muscles (abdominal and gastrocnemius), liver, and heart were isolated and processed for FAEE isolation and analysis by gas chromatography-mass spectrometry (GC-MS). Total mass of FAEE in the muscles was much greater than that found in the liver and the heart. In general, the animals that were fasted for 1 day and received ethanol had the highest FAEE levels among the three groups of animals. The major ethyl ester species in all cases were ethyl 16:0, ethyl 18:0, ethyl 18:1 n-9, and ethyl 18:2 n-6. Ethyl 20:4 n-6 and ethyl 22:6 n-3 were also present, except in the fasted 1-day group, where ethyl 22:6 disappeared, though it reappeared in the fasted 2-day group. These findings demonstrate that skeletal muscles contain high levels of FAEE that are synthesized in the body after ethanol exposure. The concentration of FAEE in skeletal muscle in this study was very similar to FAEE concentration in the liver. This differs from previous studies suggesting a low concentration of skeletal muscle FAEE with ethanol exposure.

  11. Clinical Outcomes of Living Liver Transplantation According to the Presence of Sarcopenia as Defined by Skeletal Muscle Mass, Hand Grip, and Gait Speed.

    Science.gov (United States)

    Harimoto, N; Yoshizumi, T; Izumi, T; Motomura, T; Harada, N; Itoh, S; Ikegami, T; Uchiyama, H; Soejima, Y; Nishie, A; Kamishima, T; Kusaba, R; Shirabe, K; Maehara, Y

    2017-11-01

    Sarcopenia is an independent predictor of death after living-donor liver transplantation (LDLT). However, the ability of the Asian Working Group for Sarcopenia criteria for sarcopenia (defined as reduced skeletal muscle mass plus low muscle strength) to predict surgical outcomes in patients who have undergone LDLT has not been determined. This study prospectively enrolled 366 patients who underwent LDLT at Kyushu University Hospital. Skeletal muscle area (determined by computed tomography), hand-grip strength, and gait speed were measured in 102 patients before LDLT. We investigated the relationship between sarcopenia and surgical outcomes after LDLT performed in three time periods. The number of patients with lower skeletal muscle area has increased to 52.9% in recent years. The incidence of sarcopenia according to the Asian Working Group for Sarcopenia criteria was 23.5% (24/102). Patients with sarcopenia (defined by skeletal muscle area and functional parameters) had significantly lower skeletal muscle area and weaker hand-grip strength than did those without sarcopenia. Compared with non-sarcopenic patients, patients with sarcopenia also had significantly worse liver function, greater estimated blood loss, greater incidence of postoperative complications of Clavien-Dindo grade IV or greater (including amount of ascites on postoperative day 14, total bilirubin on postoperative day 14, and postoperative sepsis), and longer postoperative hospital stay. Multiple logistic regression analysis revealed sarcopenia as a significant predictor of 6-month mortality. The combination of skeletal muscle mass and function can predict surgical outcomes in LDLT patients. Copyright © 2017 Elsevier Inc. All rights reserved.

  12. The influence of capillarization on satellite cell pool expansion and activation following exercise-induced muscle damage in healthy young men.

    Science.gov (United States)

    Nederveen, Joshua P; Joanisse, Sophie; Snijders, Tim; Thomas, Aaron C Q; Kumbhare, Dinesh; Parise, Gianni

    2018-03-15

    Skeletal muscle stem cells (satellite cells) play a crucial role in repair and remodelling of muscle in response to exercise. Satellite cells are in close spatial proximity to muscle capillaries and therefore may be influenced by them. In this study, we describe the activation and expansion of the satellite cell pool in response to eccentric contraction-induced muscle damage in individuals with significantly different levels of muscle capillarization. Individuals with greater capillarization and capacity for muscle perfusion demonstrated enhanced activation and/or expansion of the satellite cell pool allowing for an accelerated recovery of muscle function. These results provide insight into the critical relationship between muscle capillarization and satellite cells during skeletal muscle repair. Factors that determine the skeletal muscle satellite cell (SC) response remain incompletely understood. It is known, however, that SC activation status is closely related to the anatomical relationship between SCs and muscle capillaries. We investigated the impact of muscle fibre capillarization on the expansion and activation status of SCs following a muscle-damaging exercise protocol in healthy young men. Twenty-nine young men (21 ± 0.5 years) performed 300 unilateral eccentric contractions (180 deg s -1 ) of the knee extensors. Percutaneous muscle biopsies from the vastus lateralis and blood samples from the antecubital vein were taken prior to (Pre) exercise and at 6, 24, 72 and 96 h of post-exercise recovery. A comparison was made between subjects who had a relative low mixed muscle capillary-to-fibre perimeter exchange index (CFPE; Low group) and high mixed muscle CFPE index (High group) at baseline. Type I and type II muscle fibre size, myonuclear content, capillarization, and SC response were determined via immunohistochemistry. Overall, there was a significant correlation (r = 0.39; P < 0.05) between the expansion of SC content (change in total Pax7

  13. Influence of the tip mass on the tip-sample interactions in TM-AFM

    Energy Technology Data Exchange (ETDEWEB)

    Pishkenari, Hossein Nejat, E-mail: nejat@mech.sharif.edu [Nano-Robotics Laboratory, Center of Excellence in Design, Robotics and Automation, School of Mechanical Engineering, Sharif University of Technology, Tehran, P.O. Box 11365-9465 (Iran, Islamic Republic of); Meghdari, Ali [Nano-Robotics Laboratory, Center of Excellence in Design, Robotics and Automation, School of Mechanical Engineering, Sharif University of Technology, Tehran, P.O. Box 11365-9465 (Iran, Islamic Republic of)

    2011-07-15

    This paper focuses on the influences of the tip mass ratio (the ratio of the tip mass to the cantilever mass), on the excitation of higher oscillation eigenmodes and also on the tip-sample interaction forces in tapping mode atomic force microscopy (TM-AFM). A precise model for the cantilever dynamics capable of accurate simulations is essential for the investigation of the tip mass effects on the interaction forces. In the present work, the finite element method (FEM) is used for modeling the AFM cantilever to consider the oscillations of higher eigenmodes oscillations. In addition, molecular dynamics (MD) is used to calculate precise data for the tip-sample force as a function of tip vertical position with respect to the sample. The results demonstrate that in the presence of nonlinear tip-sample interaction forces, the tip mass ratio plays a significant role in the excitations of higher eigenmodes and also in the normal force applied on the surface. Furthermore, it has been shown that the difference between responses of the FEM and point-mass models in different system operational conditions is highly affected by the tip mass ratio. -- Highlights: {yields} A strong correlation exists between the tip mass ratio and the 18th harmonic amplitude. {yields} Near the critical tip mass ratio a small change in the tip mass may lead to a significant force change. {yields} Inaccuracy of the lumped model depends significantly on the tip mass ratio.

  14. Impact of Skeletal Muscle Mass Index, Intramuscular Adipose Tissue Content, and Visceral to Subcutaneous Adipose Tissue Area Ratio on Early Mortality of Living Donor Liver Transplantation.

    Science.gov (United States)

    Hamaguchi, Yuhei; Kaido, Toshimi; Okumura, Shinya; Kobayashi, Atsushi; Shirai, Hisaya; Yagi, Shintaro; Kamo, Naoko; Okajima, Hideaki; Uemoto, Shinji

    2017-03-01

    Skeletal muscle depletion has been shown to be an independent risk factor for poor survival in various diseases. However, in surgery, the significance of other body components including visceral and subcutaneous adipose tissue remains unclear. This retrospective study included 250 adult patients undergoing living donor liver transplantation (LDLT) between January 2008 and April 2015. Using preoperative plain computed tomography imaging at the third lumbar vertebra level, skeletal muscle mass, muscle quality, and visceral adiposity were evaluated by the skeletal muscle mass index (SMI), intramuscular adipose tissue content (IMAC), and visceral to subcutaneous adipose tissue area ratio (VSR), respectively. The cutoff values of these parameters were determined for men and women separately using the data of 657 healthy donors for LDLT between 2005 and 2016. Impact of these parameters on outcomes after LDLT was analyzed. VSR was significantly correlated with patient age (P = 0.041), neutrophil-lymphocyte ratio (P mass index (P normal group. On multivariate analysis, low SMI (hazard ratio [HR], 2.367, P = 0.002), high IMAC (HR, 2.096, P = 0.004), and high VSR (HR, 2.213, P = 0.003) were identified as independent risk factors for death after LDLT. Preoperative visceral adiposity, as well as low muscularity, was closely involved with posttransplant mortality.

  15. Muscle Weakness Is Associated With an Increase of Left Ventricular Mass Through Excessive Blood Pressure Elevation During Exercise in Patients With Hypertension.

    Science.gov (United States)

    Kamada, Yumi; Masuda, Takashi; Tanaka, Shinya; Akiyama, Ayako; Nakamura, Takeshi; Hamazaki, Nobuaki; Okubo, Michihito; Kobayashi, Naoyuki; Ako, Junya

    2017-08-03

    Autonomic imbalance in hypertension induces excessive blood pressure (BP) elevation during exercise, thereby increasing left ventricular mass (LVM). Although muscle weakness enhances autonomic imbalance by stimulating muscle sympathetic activity during exercise, it is unclear whether muscle weakness is associated with an increase of LVM in patients with hypertension. This study aimed to investigate the relationships between muscle weakness, BP elevation during exercise, and LVM in these patients. Eighty-six hypertensive patients aged 69 ± 8 years with controlled resting BP (ie, exercise test performed at moderate intensity (ΔNORA and ΔPWV, respectively). A difference between baseline and peak systolic BP during the exercise test was defined as BP elevation during exercise (ΔSBP). Relationships between muscle strength, ΔNORA, ΔPWV, ΔSBP, BNP, and LVMI were analyzed, and significant factors increasing LVM were identified using univariate and multivariate regression analyses. Muscle strength was negatively correlated with ΔNORA (r = -0.202, P = 0.048), ΔPWV (r = -0.328, P = 0.002), ΔSBP (r = -0.230, P = 0.033), BNP (r = -0.265, P = 0.014), and LVMI (r = -0.233, P = 0.031). LVMI was positively correlated with ΔPWV (r = 0.246, P = 0.023) and ΔSBP (r = 0.307, P = 0.004). Muscle strength was a significant independent factor associated with LVMI (β = -0.331, P = 0.010). Our findings suggest that muscle weakness is associated with an increase of LVM through excessive BP elevation during exercise in patients with hypertension.

  16. Muscle Synergies Heavily Influence the Neural Control of Arm Endpoint Stiffness and Energy Consumption.

    Science.gov (United States)

    Inouye, Joshua M; Valero-Cuevas, Francisco J

    2016-02-01

    Much debate has arisen from research on muscle synergies with respect to both limb impedance control and energy consumption. Studies of limb impedance control in the context of reaching movements and postural tasks have produced divergent findings, and this study explores whether the use of synergies by the central nervous system (CNS) can resolve these findings and also provide insights on mechanisms of energy consumption. In this study, we phrase these debates at the conceptual level of interactions between neural degrees of freedom and tasks constraints. This allows us to examine the ability of experimentally-observed synergies--correlated muscle activations--to control both energy consumption and the stiffness component of limb endpoint impedance. In our nominal 6-muscle planar arm model, muscle synergies and the desired size, shape, and orientation of endpoint stiffness ellipses, are expressed as linear constraints that define the set of feasible muscle activation patterns. Quadratic programming allows us to predict whether and how energy consumption can be minimized throughout the workspace of the limb given those linear constraints. We show that the presence of synergies drastically decreases the ability of the CNS to vary the properties of the endpoint stiffness and can even preclude the ability to minimize energy. Furthermore, the capacity to minimize energy consumption--when available--can be greatly affected by arm posture. Our computational approach helps reconcile divergent findings and conclusions about task-specific regulation of endpoint stiffness and energy consumption in the context of synergies. But more generally, these results provide further evidence that the benefits and disadvantages of muscle synergies go hand-in-hand with the structure of feasible muscle activation patterns afforded by the mechanics of the limb and task constraints. These insights will help design experiments to elucidate the interplay between synergies and the mechanisms

  17. THE RELATION OF FAT FREE MASS TO LUNG FUNCTION, MUSCLE STRENGTH AND EXERCISE PERFORMANCE IN PATIENTS WITH EMPHYSEMA

    OpenAIRE

    竹中, 英昭

    2000-01-01

    The purpose of this study was to investigate changes of body composition in patients with pulmonary emphysema (PE) and their influence on physiological function. Body composition analysis by means of bioelectrical impedance analysis (BIA) was performed in 36 patients with stable PE and 19 age-matched healthy controls. I compared fat free mass (FFM) and body fat (BF), as a percentage of ideal body weight (FFM/IBW, BF/IBW), between patients with PE and healthy controls. FFM/IBW and BF /IBW were...

  18. Liquid chromatography – tandem mass spectrometry method for the determination of ten tetracycline residues in muscle samples

    Directory of Open Access Journals (Sweden)

    Gajda Anna

    2015-09-01

    Full Text Available A liquid chromatography – tandem mass spectrometry (LC-MS/MS method for the determination of oxytetracycline (OTC, 4-epi oxytetracycline (4-epi OTC, tetracycline (TC, 4-epi tetracycline (4-epi TC, chlortetracycline (CTC, 4-epi chlortetracycline (4-epi CTC, doxycycline (DC, minocycline (MINO, methacycline (META and rolitetracycline (ROLI residues in muscles was developed. The procedure consisted of an oxalic acid extraction followed by protein removal with trichloroacetic acid. Further solid phase clean-up on polymeric (Strata X reversed phase columns was performed to obtain an extract suitable for LC-MS/MS analysis. The tetracyclines were separated on a C 18 analytical column with mobile phase consisting of 0.01% formic acid in acetonitrile and 0.01% formic acid in water in gradient mode. The method was validated according to the Commission Decision 2002/657/EC. The recoveries of all target compounds were 91.8% – 103.6%. The decision limits were from 109.0 to 119.8 μg/kg and detection capability varied within the range of 122.2 to 137.6 μg/kg, depending on the analyte.

  19. Spatial patterns of North Atlantic Oscillation influence on mass balance variability of European glaciers

    Directory of Open Access Journals (Sweden)

    B. Marzeion

    2012-06-01

    Full Text Available We present and validate a set of minimal models of glacier mass balance variability. The most skillful model is then applied to reconstruct 7735 individual time series of mass balance variability for all glaciers in the European Alps and Scandinavia. Subsequently, we investigate the influence of atmospheric variability associated with the North Atlantic Oscillation (NAO on the glaciers' mass balances.

    We find a spatial coherence in the glaciers' sensitivity to NAO forcing which is caused by regionally similar mechanisms relating the NAO forcing to the mass balance: in southwestern Scandinavia, winter precipitation causes a correlation of mass balances with the NAO. In northern Scandinavia, temperature anomalies outside the core winter season cause an anti-correlation between NAO and mass balances. In the western Alps, both temperature and winter precipitation anomalies lead to a weak anti-correlation of mass balances with the NAO, while in the eastern Alps, the influences of winter precipitation and temperature anomalies tend to cancel each other, and only on the southern side a slight anti-correlation of mass balances with the NAO prevails.

  20. Integrative Analyses of miRNA-mRNA Interactions Reveal let-7b, miR-128 and MAPK Pathway Involvement in Muscle Mass Loss in Sex-Linked Dwarf Chickens

    Science.gov (United States)

    Luo, Wen; Lin, Shumao; Li, Guihuan; Nie, Qinghua; Zhang, Xiquan

    2016-01-01

    The sex-linked dwarf (SLD) chicken is an ideal model system for understanding growth hormone (GH)-action and growth hormone receptor (GHR) function because of its recessive mutation in the GHR gene. Skeletal muscle mass is reduced in the SLD chicken with a smaller muscle fiber diameter. Our previous study has presented the mRNA and miRNA expression profiles of the SLD chicken and normal chicken between embryo day 14 and seven weeks of age. However, the molecular mechanism of GHR-deficient induced muscle mass loss is still unclear, and the key molecules and pathways underlying the GHR-deficient induced muscle mass loss also remain to be illustrated. Here, by functional network analysis of the differentially expressed miRNAs and mRNAs between the SLD and normal chickens, we revealed that let-7b, miR-128 and the MAPK pathway might play key roles in the GHR-deficient induced muscle mass loss, and that the reduced cell division and growth are potential cellular processes during the SLD chicken skeletal muscle development. Additionally, we also found some genes and miRNAs involved in chicken skeletal muscle development, through the MAPK, PI3K-Akt, Wnt and Insulin signaling pathways. This study provides new insights into the molecular mechanism underlying muscle mass loss in the SLD chickens, and some regulatory networks that are crucial for chicken skeletal muscle development. PMID:26927061

  1. Spatial factors and muscle spindle input influence the generation of neuromuscular responses to stimulation of the human foot

    Science.gov (United States)

    Layne, Charles S.; Forth, Katharine E.; Abercromby, Andrew F. J.

    2005-05-01

    Removal of the mechanical pressure gradient on the soles leads to physiological adaptations that ultimately result in neuromotor degradation during spaceflight. We propose that mechanical stimulation of the soles serves to partially restore the afference associated with bipedal loading and assists in attenuating the negative neuromotor consequences of spaceflight. A dynamic foot stimulus device was used to stimulate the soles in a variety of conditions with different stimulation locations, stimulation patterns and muscle spindle input. Surface electromyography revealed the lateral side of the sole elicited the greatest neuromuscular response in ankle musculature, followed by the medial side, then the heel. These responses were modified by preceding stimulation. Neuromuscular responses were also influenced by the level of muscle spindle input. These results provide important information that can be used to guide the development of a "passive" countermeasure that relies on sole stimulation and can supplement existing exercise protocols during spaceflight.

  2. Passive stiffness of monoarticular lower leg muscles is influenced by knee joint angle.

    Science.gov (United States)

    Ateş, Filiz; Andrade, Ricardo J; Freitas, Sandro R; Hug, François; Lacourpaille, Lilian; Gross, Raphael; Yucesoy, Can A; Nordez, Antoine

    2018-03-01

    While several studies demonstrated the occurrence of intermuscular mechanical interactions, the physiological significance of these interactions remains a matter of debate. The purpose of this study was to quantify the localized changes in the shear modulus of the gastrocnemius lateralis (GL), monoarticular dorsi- and plantar-flexor muscles induced by a change in knee angle. Participants underwent slow passive ankle rotations at the following two knee positions: knee flexed at 90° and knee fully extended. Ultrasound shear wave elastography was used to assess the muscle shear modulus of the GL, soleus [both proximally (SOL-proximal) and distally (SOL distal)], peroneus longus (PERL), and tibialis anterior (TA). This was performed during two experimental sessions (experiment I: n = 11; experiment II: n = 10). The shear modulus of each muscle was compared between the two knee positions. The shear modulus was significantly higher when the knee was fully extended than when the knee was flexed (P passive muscle force, these results provide evidence of a non-negligible intermuscular mechanical interaction between the human lower leg muscles during passive ankle rotations. The role of these interactions in the production of coordinated movements requires further investigation.

  3. Whole-body electromyostimulation as a means to impact muscle mass and abdominal body fat in lean, sedentary, older female adults: subanalysis of the TEST-III trial

    Directory of Open Access Journals (Sweden)

    Kemmler W

    2013-10-01

    Full Text Available Wolfgang Kemmler, Simon von StengelInstitute of Medical Physics, University of Erlangen-Nürnberg, Erlangen, GermanyBackground: The primary aim of this study was to determine the effect of 12 months of whole-body electromyostimulation (WB-EMS exercise on appendicular muscle mass and abdominal fat mass in subjects specifically at risk for sarcopenia and abdominal obesity, but unable or unwilling to exercise conventionally.Methods: Forty-six lean, nonsportive (<60 minutes of exercise per week, elderly women (aged 75 ± 4 years with abdominal obesity according to International Diabetes Federation criteria were randomly assigned to either a WB-EMS group (n=23 which performed 18 minutes of intermittent, bipolar WB-EMS (85 Hz three sessions in 14 days or an "active" control group (n=23. Whole-body and regional body composition was assessed by dual energy X-ray absorptiometry to determine appendicular muscle mass, upper leg muscle mass, abdominal fat mass, and upper leg fat mass. Maximum strength of the leg extensors was determined isometrically by force plates.Results: After 12 months, significant intergroup differences were detected for the primary endpoints of appendicular muscle mass (0.5% ± 2.0% for the WB-EMS group versus −0.8% ± 2.0% for the control group, P=0.025 and abdominal fat mass (−1.2% ± 5.9% for the WB-EMS group versus 2.4% ± 5.8% for the control group, P=0.038. Further, upper leg lean muscle mass changed favorably in the WB-EMS group (0.5% ± 2.5% versus −0.9% ± 1.9%, in the control group, P=0.033, while effects for upper leg fat mass were borderline nonsignificant (−0.8% ± 3.5% for the WB-EMS group versus 1.0% ± 2.6% for the control group, P=0.050. With respect to functional parameters, the effects for leg extensor strength were again significant, with more favorable changes in the WB-EMS group (9.1% ± 11.2% versus 1.0% ± 8.1% in the control group, P=0.010.Conclusion: In summary, WB-EMS showed positive effects on the

  4. The influence of muscle forces on the stress distribution in the lumbar spine

    DEFF Research Database (Denmark)

    Wong, C; Rasmussen, J; Simonsen, Erik B.

    2011-01-01

    muscles. Results: In general the von Mises stress was larger by 30 %, and even higher when looking at the von Mises stress distribution in the superio-anterior and central part of the vertebral body and in the pedicles. Conclusion: The application of spine muscles to a finite element model showed markedly...... larger von Mises stress responses in the central and anterior part of the vertebral body, which can be tolerated in the young and healthy spine, but it would increase the risk of compression fractures in the elderly, osteoporotic spine.......Introduction: Previous studies of bone stresses in the human lumbar spine have relied on simplified models when modeling the spinal musculature, even though muscle forces are likely major contributors to the stresses in the vertebral bones. Detailed musculoskeletal spine models have recently become...

  5. [Hotels and sanatoria: the influence of tuberculosis on mass tourism architecture].

    Science.gov (United States)

    Morales, Eduardo Jiménez; Díaz, Ingrid Carolina Vargas

    2017-01-01

    The aim of this article is to verify the influence of tuberculosis on mass tourism architecture. To achieve this, the paper analyses the typological evolution of the hotel since the middle of the nineteenth century, when the first sanatoria appeared in the alpine resorts. A study that creates links between the progress in architecture and the medical therapy advances. The goal is to highlight the hybridisation process between both architectural typologies. Although this overlapping is developed until the Second World War, the influence of its mixture is still present in contemporary mass tourism architecture.

  6. Efficacy of phosphatidic acid ingestion on lean body mass, muscle thickness and strength gains in resistance-trained men

    Directory of Open Access Journals (Sweden)

    Hoffman Jay R

    2012-10-01

    Full Text Available Abstract Background Phosphatidic acid (PA has been reported to activate the mammalian target of rapamycin (mTOR signaling pathway and is thought to enhance the anabolic effects of resistance training. The purpose of this pilot study was to examine if oral phosphatidic acid administration can enhance strength, muscle thickness and lean tissue accruement during an 8-week resistance training program. Methods Sixteen resistance-trained men were randomly assigned to a group that either consumed 750 mg of PA (n = 7, 23.1 ± 4.4 y; 176.7 ± 6.7 cm; 86.5 ± 21.2 kg or a placebo (PL, n = 9, 22.5 ± 2.0 y; 179.8 ± 5.4 cm; 89.4 ± 13.6 kg group. During each testing session subjects were assessed for strength (one repetition maximum [1-RM] bench press and squat and body composition. Muscle thickness and pennation angle were also measured in the vastus lateralis of the subject’s dominant leg. Results Subjects ingesting PA demonstrated a 12.7% increase in squat strength and a 2.6% increase in LBM, while subjects consuming PL showed a 9.3% improvement in squat strength and a 0.1% change in LBM. Although parametric analysis was unable to demonstrate significant differences, magnitude based inferences indicated that the Δ change in 1-RM squat showed a likely benefit from PA on increasing lower body strength and a very likely benefit for increasing lean body mass (LBM. Conclusions Results of this study suggest that a combination of a daily 750 mg PA ingestion, combined with a 4-day per week resistance training program for 8-weeks appears to have a likely benefit on strength improvement, and a very likely benefit on lean tissue accruement in young, resistance trained individuals.

  7. Influence of the extraocular muscle proprioceptors on the orientation of the vestibulo-ocular reflex.

    Science.gov (United States)

    Pettorossi, V E; Errico, P; Ferraresi, A; Manni, E

    1996-03-01

    In the intact brain lamb, unilateral electrolytic lesion of the medial dorso-lateral portion of the semilunar ganglion containing the first order neurons of the eye muscle proprioception induced modifications of the horizontal and vertical vestibulo-ocular reflex (HVOR and VVOR) which consisted in marked alterations of the trajectories of the quick phases, while the slow phases were scarcely affected. Similar results were observed after section of the branches described by Winckler in the retrobulbar region along the extraocular muscle proprioceptive information travels. These findings extend those of previous investigations carried out in decorticate animals.

  8. [Influence of the occlusal interference time on masticatory muscle mechanical hyperalgesia in rats].

    Science.gov (United States)

    Liu, Cun-rui; Xu, Xiao-xiang; Cao, Ye; Xie, Qiu-fei

    2016-02-18

    To investigate the relationship between the removal time of 0.2 mm occlusal interference and the recovery of masticatory muscle mechanical hyperalgesia in rats. Forty male Sprague-Dawley rats (200-220 g) were randomly assigned to eight groups, with five rats in each group: (1) naive group: these rats were anesthetized and their mouths were forced open for about 5 min (the same duration as the other groups), but restorations were not applied; (2) sham-occlusal interference control group: bands were bonded to the right maxillary first molars which did not interfere with occlusion; (3)occlusal interference group: 0.2 mm thick crowns were bonded to the right maxillary first molars; (4) 2, 3, 4, 5, and 6 d removal of occlusal interference groups: 0.2 mm thick crowns were bonded to the right maxillary first molars and removed on days 2, 3, 4, 5, and 6. The naive group and sham-occlusal interference control group were control groups. The other groups were experimental groups. Bilateral masticatory muscle mechanical withdrawal thresholds were tested on pre-application days 1, 2, and 3, and on post-application days 1, 3, 5, 7, 10, 14, 21 and 28. The rats were weighed on pre-application day 1 and on post-application days 1, 2, 3, 4, 5, 6, and 7. Between the naive group and the sham-occlusal interference control group, there was no significant difference in the masticatory muscle mechanical withdrawal threshold of bilateral temporalis and masseters at each time point. No significant difference was detected between the contralateral side and ipsilateral side in experimental groups (P>0.05). In the 2, 3, 4, and 5 d removal of occlusal interference groups, the masticatory muscle mechanical withdrawal thresholds decreased after occlusal interference and increased after removal of the crowns and recovered to the baseline on days 7, 10, 14, and 14, respectively [the masticatory muscle mechanical withdrawal thresholds of right masseter muscle were (137.46 ± 2.08) g, (139.02 ± 2

  9. Interdependence of physical inactivity, loss of muscle mass and low dietary intake: Extrapulmonary manifestations in older chronic obstructive pulmonary disease patients.

    Science.gov (United States)

    Yoshimura, Kazuya; Sato, Susumu; Muro, Shigeo; Yamada, Minoru; Hasegawa, Koichi; Kiyokawa, Hirofumi; Mishima, Michiaki; Aoyama, Tomoki

    2018-01-01

    Extrapulmonary manifestations, such as reductions in skeletal muscle and physical inactivity, are important clinical features of patients with chronic obstructive pulmonary disease (COPD), and might depend on the severity of COPD. As it is still unclear whether the relationship between muscle loss and physical inactivity is dominated by a disease-specific relationship or caused by patient factors, including physiological aging, we aimed to investigate the pulmonary or extrapulmonary factors associated with physical inactivity among older COPD patients. A total of 38 older male COPD patients (aged ≥65 years) were enrolled, and were evaluated cross-sectionally. Skeletal muscle mass was measured using bioelectrical impedance, and physical activity and energy intake were recorded for 2 weeks using a pedometer and diary. Daily step counts were successfully evaluated in 28 participants (mean forced expiratory volume in 1 s [%predicted; %FEV 1 ]; 49.5%), and ranged widely. The mean step counts was 5166 steps/day, and found to have a significant relationship with dyspnea (r = -0.46), diffusing capacity (r = 0.47), %FEV1 (r = 0.44), skeletal muscle index (r = 0.59) and total dietary intake (r = 0.47), but not with age (P = 0.14). A stepwise multivariate analysis showed that the skeletal muscle index (β = 0.50) and total dietary intake (β = 0.35) were significant determinants of the daily step count (R 2 = 0.46, p physical activity, skeletal muscle mass and dietary intake are more closely correlated with physical activity in COPD patients. Because physical inactivity might be the strongest predictor of prognosis, the present results suggest that a comprehensive treatment strategy must be considered for older COPD patients to improve their extrapulmonary manifestations and pulmonary dysfunction. Geriatr Gerontol Int 2018; 18: 88-94. © 2017 Japan Geriatrics Society.

  10. Muscle thickness and muscle quality measured by ultrasound: influence of different sites of measurement DOI: 10.5007/1980-0037.2011v13n2p87

    Directory of Open Access Journals (Sweden)

    Ronei Silveira Pinto

    2011-03-01

    Full Text Available The aims of this study were: a to investigate differences in muscle thickness (MT measured by ultrasound and muscle quality (MQ at three sites in the elbow flexors and knee extensors, and b to correlate MT with isometric force production of the elbow flexors and knee extensors. Sixty-nine young male subjects participated in this study. The isometric force production values of the elbow flexors and knee extensors were obtained at 90° and 60°, respectively. MT was assessed at three sites in the elbow flexors (proximal – BB1, middle – BB2, and distal – BB3 and knee extensors (proximal – RI1, middle – RI2, and distal – RI3. Differences between the three measurements of MT and MQ were evaluated by one-way repeated measures ANOVA. Pearson’s correlation test was used to assess the correlation between MT and isometric force. The level of significance was set at p<0.05. The results showed significant differences (p<0.001 between the three MT and MQ sites in the elbow flexors (BB1, BB2, BB3 and in the knee extensors (RI1, RI2, RI3. The correlation between BB1, BB2 and BB3 and force production was r=0.57, r=0.52 and r=0.59, respectively (p<0.05. In the knee extensors, the correlation between RI1, RI2 and RI3 and force production was r=0.47, r=0.51 and r=0.53, respectively (p<0.01. There were significant differences in MQ between elbow flexors (p<0.001 and knee extensors (p<0.001. The present results showed that the site of measurement has a significant influence on MT and MQ. Furthermore, MT was positively correlated with isometric force production in the elbow flexors and knee extensors.

  11. The additional value of bioelectrical impedance analysis-derived muscle mass as a screening tool in geriatric assessment for fall prevention.

    Science.gov (United States)

    Van Puyenbroeck, Karolien; Roelandts, Lieven; Van Deun, Thomas; Van Royen, Paul; Verhoeven, Veronique

    2012-01-01

    The decline in skeletal muscle in old age is a factor in the development of functional limitations. The objective of this study was to assess if there is a correlation between muscle mass based on bioelectrical impedance analysis (BIA) detection and the fall incidence in nursing home residents and to examine the risk factors for falling in nursing home residents. This prospective cohort study was part of a longitudinal study on nutritional issues in 52 nursing homes in Antwerp (Belgium) from October 2007 to April 2008. Two hundred and seventy-six people aged 65 years and older were included. Each subject was assessed with BIA, the timed get-up-and-go test, the Katz score, the Mini Nutritional Assessment - Short Form and the 36-Item Short Form Health Survey. The primary outcome parameter was fall incidence during the study. The prevalence of sarcopenia varied from 24.3 to 81.5% depending on which definition was used. No association was found between BIA-derived muscle mass and fall incidence. Logistic regression analysis showed that gait speed (odds ratio 1.029; p = 0.003) and mental health (odds ratio 0.981; p = 0.015) are significantly associated with fall incidence in nursing homes. A receiver operating characteristic curve showed that none of the BIA-derived muscle parameters are good predictors of the risk of falling. This study shows that there is no association between sarcopenia based on BIA and fall incidence and that BIA-derived muscle mass has no additional value in predicting fall incidents compared to the timed get-up-and-go test. Copyright © 2012 S. Karger AG, Basel.

  12. Concurrent Label-Free Mass Spectrometric Analysis of Dystrophin Isoform Dp427 and the Myofibrosis Marker Collagen in Crude Extracts from mdx-4cv Skeletal Muscles

    Science.gov (United States)

    Murphy, Sandra; Zweyer, Margit; Mundegar, Rustam R.; Henry, Michael; Meleady, Paula; Swandulla, Dieter; Ohlendieck, Kay

    2015-01-01

    The full-length dystrophin protein isoform of 427 kDa (Dp427), the absence of which represents the principal abnormality in X-linked muscular dystrophy, is difficult to identify and characterize by routine proteomic screening approaches of crude tissue extracts. This is probably related to its large molecular size, its close association with the sarcolemmal membrane, and its existence within a heterogeneous glyco