Musculoskeletal Morphology and Joint Flexibility-Associated Functional Characteristics across Three Time Points during the Menstrual Cycle in Female Contemporary Dancers.

Findings are inconsistent with regards to whether menstrual cycle phase-associated changes in physical functioning exist. It is possible that such discrepancies are due to varying rigour in experimental approaches. The current study aimed to systematically evaluate any effect of carefully tracked menstrual cycle phase on precisely measured muscle structure and function in a physically active group (contemporary dancers). Eleven women aged (M [SD]) 23.5 [2.94] years, undergoing 10.5 [1.73] hours of contemporary dance practice and 6.12 [2.36] hours of other physical activity per week, were recruited. Sex hormone level (enzyme-linked immunosorbent assays (ELISA), skin temperature and ovulation kits), physical pain assessments (Ice Water Test, Visual Analogue Scale, The Physical Activity Readiness Questionnaire, Self-Estimated Functional Inability Because of Pain Questionnaire, and Pain Anxiety Symptoms Scale), muscle architecture measurement (B-mode ultrasonography), and physical functioning (dynamometry, force-platform and electromyography) on both lower limbs were measured at three time points during one cycle, following three months of menstrual cycle monitoring. There was no difference in musculoskeletal flexibility variables between follicular, ovulatory, or luteal phases. Nonetheless, oestrogen change was associated with variability in 11 musculoskeletal variables, progesterone change was associated with variability in 7, and relaxin change was associated with variability in 15. Negative correlations existed between progesterone and flexibility and between oestrogen and jump variables. Moreover, oestrogen and relaxin were associated with increased musculoskeletal compliance, whilst progesterone was associated with increased muscle stiffness. In short, in absolute sex hormone levels, 'inter-individual' variances appear more impactful than 'intra-individual' variances. Not only are oestrogen and progesterone associated with differing musculoskeletal outcomes, but relaxin is also associated with musculoskeletal compliance changes. These effects are anticipated to impact jump height and flexibility, and hence, they could be expected to affect overall physical performance, including dance.

Sedentary behaviour (especially accumulation pattern) has an independent negative impact on skeletal muscle size and architecture in community-dwelling older adults.

Prolonged sedentary behaviour (SB) i.e. longer bouts, is suggested to have a range of negative health effects, independent of habitual light and medium-to-vigorous physical activity (LIPA or MVPA). Any effect on musculoskeletal size, architecture or morphology has seldom been reported in older adults. Moreover, no study has yet determined if any association would persist following adjustment for covariates. Therefore, the aim of the present study was to investigate the associations between SB, and properties of the Gastrocnemius Medialis (GM) muscle, in a cross-sectional sample of older adults using compositional data analysis. 105 healthy older adults (73±6y) wore a thigh mounted tri-axial accelerometer for seven consecutive days, and underwent ultrasound [e.g. muscle length (Lm), anatomical cross-sectional area (ACSA), muscle volume (VM), fascicle length (LF), & physiological cross-sectional area (PCSA)], body composition (e.g. DEXA) and health (e.g. medical history) assessments. In-unadjusted models, SB time was negatively associated with ACSA at 75% of Lm (R2adj = 0.085), VM (R2adj = 0.020), and PCSA (R2adj = 0.039). Standing was positively associated with pennation angle (R2adj = 0.110), which persisted following co-variate adjustment (R2adj = 0.296). In fully adjusted models, both SB & LIPA time were associated with ACSA at 75% of Lm (Both R2adj = 0.393). Standing and light activity time were also associated with LF, VM, & PCSA (R2adj 0.116-0.573). In fully adjusted models, SB pattern parameters (i.e. the manner in which sedentary behaviour is accumulated daily throughout waking hours such as the timing, duration and frequency of sedentary bouts), were associated with GM muscle properties (R2adj 0.156-0.564) including LM, LF, and VM. The pattern, rather than accumulated daily SB time, was associated with the size and architecture of the GM. Our results suggest that regardless of co-existing habitual physical activities, SB bouts should be kept short and frequently interrupted to offset some of the deleterious ageing-related muscle architecture characteristics changes.

Concurrent Validity of Four Activity Monitors in Older Adults.

Sedentary behaviour (SB) and physical activity (PA) have been shown to be independent modulators of healthy ageing. We thus investigated the impact of activity monitor placement on the accuracy of detecting SB and PA in older adults, as well as a novel random forest algorithm trained on data from older persons. Four monitor types (ActiGraph wGT3X-BT, ActivPAL3c VT, GENEActiv Original, and DynaPort MM+) were simultaneously worn on five anatomical sites during ten different activities by a sample of twenty older adults (70.0 (12.0) years; 10 women). The results indicated that collecting metabolic equivalent (MET) data for 60 s provided the most representative results, minimising variability. In addition, thigh-worn monitors, including ActivPAL, Random Forest, and Sedentary Sphere-Thigh, exhibited superior performance in classifying SB, with balanced accuracies ≥ 94.2%. Other monitors, such as ActiGraph, DynaPort MM+, and GENEActiv Sedentary Sphere-Wrist, demonstrated lower performance. ActivPAL and GENEActiv Random Forest outperformed other monitors in participant-specific balanced accuracies for SB classification. Only thigh-worn monitors achieved acceptable overall balanced accuracies (≥80.0%) for SB, standing, and medium-to-vigorous PA classifications. In conclusion, it is advisable to position accelerometers on the thigh, collect MET data for ≥60 s, and ideally utilise population-specific trained algorithms.

Does Aerobic Exercise Facilitate Vaping and Smoking Cessation: A Systematic Review of Randomized Controlled Trials with Meta-Analysis.

Cigarette smokers try to quit using several strategies including electronic cigarette use (vaping). An alternative, easy and cheap method is exercise. However, little is known about the efficacy of aerobic exercise (AE) to augment smoking and vaping cessation. This study aimed to systematically review and discuss the reported effects of AE on long-term vaping and smoking cessation in randomized control trials (RCTs). RCTs were searched on different databases. The outcome measures included long-term vaping or smoking cessation and maximal or peak oxygen uptake (VO2max/peak) after vaping- or smoking cessation. Meta-analysis was conducted to examine the effects of AE on long-term vaping and smoking cessation, and the effects of AE on VO2max/peak. Cochrane Risk of Bias tool 2 was used to assess trials quality. Thirteen trials were included (5 high, 2 moderate and 6 low quality). Although two high quality trials revealed that 3 vigorous supervised AE sessions a week for 12 to 15 weeks increased the number of long-term successful quitters, the meta-analysis including the other trials showed that AE did not significantly increase success rate of long-term quitters. However, VO2max/peak was improved at the end of treatment. There were no trials on AE and vaping cessation. No evidence was found that AE promotes long-term smoking cessation. Nevertheless, AE improved VO2max and/or VO2peak in quitters.

Objective and subjective measures of sleep in men with Muscular Dystrophy.

PURPOSE: Despite poor sleep quality being recognised in Duchenne Muscular Dystrophy, reports from milder forms of Muscular Dystrophy (MD), and accompanied associations with quality of life (QoL), pain and fatigue, remain limited however. METHODS: Adult males (n = 15 Beckers MD (BMD), n = 12 Limb-Girdle MD (LGMD), n = 12 Fascioscapulohumeral (FSHD), n = 14 non-MD (CTRL)) completed assessments of body composition (Bio-electrical impedance), sleep (7-day 24-hour tri-axial accelerometer, Pittsburgh Sleep Quality Index (PSQI) and Insomnia Severity Index, QoL (SF36-v2), pain (Visual analogue scale), fatigue (Modified Fatigue Index Scale) and functional assessments (Brookes and Vignos). RESULTS: FSHD and BMD reported worse sleep than CTRL on the PSQI. FSHD scored worse than CTRL on the Insomnia Severity Index (P<0.05). 25-63% and 50-81% of adults with MD reported poor sleep quality using the Insomnia Severity Index and PSQI, respectively. Accelerometery identified no difference in sleep quality between groups. Associations were identified between sleep measures (PSQI global and insomnia severity) with mental or physical QoL in LGMD, BMD and FSHD. Multiple regression identified associations between sleep impairment and fatigue severity (all MDs), body composition (BMD & LGMD), upper and lower limb function (LGMD, FSHD) and age (FSHD). CONCLUSIONS: 25-81% of men with MD, depending on classification, experience sleep impairment, using self-report sleep measures. Whilst BMD and FSHD showed worse sleep outcomes than CTRL, no group difference was observed between LGMD and CTRL, however all groups showed associations with sleep impairment and higher levels of fatigue. These findings, and associations with measures of health and wellbeing, highlight an area for further research which could impact QoL in adults with MD.

Polygenic Models Partially Predict Muscle Size and Strength but Not Low Muscle Mass in Older Women.

Background: Heritability explains 45-82% of muscle mass and strength variation, yet polygenic models for muscle phenotypes in older women are scarce. Therefore, the objective of the present study was to (1) assess if total genotype predisposition score (GPSTOTAL) for a set of polymorphisms differed between older women with low and high muscle mass, and (2) utilise a data-driven GPS (GPSDD) to predict the variance in muscle size and strength-related phenotypes. Methods: In three-hundred 60- to 91-year-old Caucasian women (70.7 ± 5.7 years), skeletal muscle mass, biceps brachii thickness, vastus lateralis anatomical cross-sectional area (VLACSA), hand grip strength (HGS), and elbow flexion (MVCEF) and knee extension (MVCKE) maximum voluntary contraction were measured. Participants were classified as having low muscle mass if the skeletal muscle index (SMI) < 6.76 kg/m2 or relative skeletal muscle mass (%SMMr) < 22.1%. Genotyping was completed for 24 single-nucleotide polymorphisms (SNPs). GPSTOTAL was calculated from 23 SNPs and compared between the low and high muscle mass groups. A GPSDD was performed to identify the association of SNPs with other skeletal muscle phenotypes. Results: There was no significant difference in GPSTOTAL between low and high muscle mass groups, irrespective of classification based on SMI or %SMMr. The GPSDD model, using 23 selected SNPs, revealed that 13 SNPs were associated with at least one skeletal muscle phenotype: HIF1A rs11549465 was associated with four phenotypes and, in descending number of phenotype associations, ACE rs4341 with three; PTK2 rs7460 and CNTFR rs2070802 with two; and MTHFR rs17421511, ACVR1B rs10783485, CNTF rs1800169, MTHFR rs1801131, MTHFR rs1537516, TRHR rs7832552, MSTN rs1805086, COL1A1 rs1800012, and FTO rs9939609 with one phenotype. The GPSDD with age included as a predictor variable explained 1.7% variance of biceps brachii thickness, 12.5% of VLACSA, 19.0% of HGS, 8.2% of MVCEF, and 9.6% of MVCKE. Conclusions: In older women, GPSTOTAL did not differ between low and high muscle mass groups. However, GPSDD was associated with muscle size and strength phenotypes. Further advancement of polygenic models to understand skeletal muscle function during ageing might become useful in targeting interventions towards older adults most likely to lose physical independence.

12-Month changes of muscle strength, body composition and physical activity in adults with dystrophinopathies.

PURPOSE: Muscular dystrophy (MD) is an umbrella term for muscle wasting conditions, for which longitudinal changes in function and body composition are well established in children with Duchenne (DMD), however, changes in adults with DMD and Beckers (BMD), respectively, remain poorly reported. This study aims to assess 12-month changes in lower-limb strength, muscle size, body composition and physical activity in adults with Muscular Dystrophy (MD). METHODS: Adult males with Duchenne MD (DMD; N = 15) and Beckers MD (BMD; N = 12) were assessed at baseline and 12-months for body composition (Body fat and lean body mass (LBM)), Isometric maximal voluntary contraction (Knee-Extension (KEMVC) and Plantar-Flexion (PFMVC)) and physical activity (tri-axial accelerometry). RESULTS: 12-Month change in strength was found as -19% (PFMVC) and -14% (KEMVC) in DMD. 12-Month change in strength in BMD, although non-significant, was explained by physical activity (R2=0.532-0.585). Changes in LBM (DMD) and body fat (BMD) were both masked by non-significant changes in body mass. DISCUSSION: 12-Month changes in adults with DMD appear consistent with paediatric populations. Physical activity appears important for muscle function maintenance. Specific monitoring of body composition, and potential co-morbidities, within adults with MD is highlighted.Implications for rehabilitationQuantitative muscle strength assessment shows progressive muscle weakness in adults with Duchenne Muscular Dystrophy is comparable to paediatric reports (-14 to -19%).Physical activity should be encouraged in adults with Beckers Muscular Dystrophy, anything appears better than nothing.Body composition, rather than body mass, should be monitored closely to identify any increase in body fat.

The effects of 12 weeks' resistance training on psychological parameters and quality of life in adults with Facioscapulohumeral, Becker, and Limb-girdle dystrophies.

PURPOSE: Investigate the impact of 12-weeks' moderate-intensity resistance training on psychological parameters in ambulatory adults with Facioscapulohumeral, Becker, and Limb-girdle muscular dystrophy. METHODS: Seventeen adults with Facioscapulohumeral (n = 6), Limb-girdle (n = 6; types 2A, 2B, 2L, and 2I), or Becker (n = 5) muscular dystrophy took part. Participants were tested at baseline (PRE), after a 12-week control period (PRE2), and after a 12-week supervised resistance training programme (POST). Training included multi-joint and single-joint resistance exercises. Outcomes from self-report questionnaires were health-related quality of life, depressive symptoms, trait anxiety, self-esteem, and physical self-worth. RESULTS: No difference in outcome measures, except depressive symptoms, was found in the control period (PRE to PRE2). Symptoms of depression were reduced by 9% from PRE to PRE2 (p < 0.05) and by a further 19% from PRE2 to POST (p < 0.05). Other changes from PRE2 to POST were that trait anxiety reduced by 10%, self-esteem increased by 10%, physical self-worth increased by 20%, and quality of life improved in 8 domains (p < 0.05). CONCLUSION: These findings demonstrate the positive impact of moderate-intensity resistance training on psychological health and quality of life in adults with Facioscapulohumeral, Becker, and Limb-girdle muscular dystrophies.Implications for rehabilitationResistance training can have a positive impact on psychological health and quality of life in adults with Facioscapulohumeral, Becker, and Limb-girdle muscular dystrophy.Healthcare professionals should consider including moderate-intensity resistance training within the management and treatment programmes of adults with Facioscapulohumeral, Becker, and Limb-girdle muscular dystrophy.

Quantitative assessment of sitting time in ambulant adults with Muscular Dystrophy.

BACKGROUND: Current investigations into physical behaviour in Muscular Dystrophy (MD) have focussed largely on physical activity (PA). Negative health behaviours such as sedentary behaviour (Physical Behaviour) and sitting time (Posture Classification) are widely recognised to negatively influence health, but by contrast are poorly reported, yet could be easier behaviours to modify. METHODS: 14 ambulant men with MD and 12 healthy controls (CTRL) subjects completed 7-days of free-living with wrist-worn accelerometry, assessing physical behaviour (SB or PA) and Posture Classification (Sitting or Standing), presented at absolute (minutes) or relative (% Waking Hours). Participant body composition (Fat Mass and Fat Free Mass) were assessed by Bioelectrical Impedance, while functional status was assessed by 10 m walk test and a functional scale (Swinyard Scale). RESULTS: Absolute Sedentary Behaviour (2.2 Hours, p = 0.025) and Sitting Time (1.9 Hours, p = 0.030 was greater in adults with MD compared to CTRL and Absolute Physical Activity (3.4 Hours, p < 0.001) and Standing Time (3.2 Hours, p < 0.001) was lower in adults with MD compared to CTRL. Absolute hours of SB was associated with Fat Mass (Kg) (R = 0.643, p < 0.05) in ambulatory adults with MD. DISCUSSION: This study has demonstrated increased Sedentary Behaviour (2.2 hours) and Sitting time (1.9 Hours) in adults with MD compared to healthy controls. Extended waking hours in sitting and SB raises concerns with regards to progression of potential cardio-metabolic diseases and co-morbidities in MD.

Sarcopenia, Obesity, and Sarcopenic Obesity: Relationship with Skeletal Muscle Phenotypes and Single Nucleotide Polymorphisms.

Obesity may aggravate the effects of sarcopenia on skeletal muscle structure and function in the elderly, but no study has attempted to identify the gene variants associated with sarcopenia in obese women. Therefore, the aims of the present study were to: (1) describe neuromuscular function in sarcopenic and non-sarcopenic women with or without obesity; (2) identify gene variants associated with sarcopenia in older obese women. In 307 Caucasian women (71 ± 6 years, 66.3 ± 11.3 kg), skeletal muscle mass was estimated using bioelectric impedance, and function was tested with a 30 s one-leg standing-balance test. Biceps brachii thickness and vastus lateralis cross-sectional area (VLACSA) were measured with B-mode ultrasonography. Handgrip strength, maximum voluntary contraction elbow flexion (MVCEF), and knee extension torque (MVCKE) were measured by dynamometry, and MVCKE/VLACSA was calculated. Genotyping was performed for 24 single-nucleotide polymorphisms (SNPs), selected based on their previous associations with muscle-related phenotypes. Based on sarcopenia and obesity thresholds, groups were classified as sarcopenic obese, non-sarcopenic obese, sarcopenic non-obese, or non-sarcopenic non-obese. A two-way analysis of covariance was used to assess the main effects of sarcopenia and obesity on muscle-related phenotypes and binary logistic regression was performed for each SNP to investigate associations with sarcopenia in obesity. There were no significant obesity * sarcopenic status interactions for any of the investigated muscle-related phenotypic parameters. Neither sarcopenia nor obesity had a significant effect on biceps brachii thickness, but sarcopenia was associated with lower VLACSA (p = 0.003). Obesity was associated with lower MVCEF (p = 0.032), MVCKE (p = 0.047), and MVCKE/VLACSA (p = 0.012) with no significant effect of sarcopenia. Adjusted for age and height, three SNPs (ACTN3 rs1815739, MTHFR rs1801131, and MTHFR rs1537516) were associated with sarcopenia in obese participants. Sarcopenia was associated with a smaller muscle size, while obesity resulted in a lower muscle quality irrespective of sarcopenia. Three gene variants (ACTN3 rs1815739, MTHFR rs1801131, and MTHFR rs1537516) suspected to affect muscle function, homocysteine metabolism, or DNA methylation, respectively, were associated with sarcopenia in obese elderly women. Understanding the skeletal muscle features affected by sarcopenia and obesity, and identification of genes related to sarcopenia in obese women, may facilitate early detection of individuals at particular risk of sarcopenic obesity.

Dietary Protein Requirement Threshold and Micronutrients Profile in Healthy Older Women Based on Relative Skeletal Muscle Mass.

Although multiple nutrients have shown protective effects with regard to preserving muscle function, the recommended amount of dietary protein and other nutrients profile on older adults for maintenance of high muscle mass is still debatable. The aims of this paper were to: (1) identify dietary differences between older women with low and high relative skeletal muscle mass, and (2) identify the minimal dietary protein intake associated with high relative skeletal muscle mass and test the threshold ability to determine an association with skeletal muscle phenotypes. Older women (n = 281; 70 ± 7 years, 65 ± 14 kg), with both low and high relative skeletal muscle mass groups, completed a food questionnaire. Skeletal muscle mass, fat-free mass (FFM), biceps brachii thickness, vastus lateralis anatomical cross-sectional area (VLACSA), handgrip strength (HGS), maximum elbow flexion torque (MVCEF), maximum knee extension torque (MVCKE), muscle quality (HGS/Body mass), and fat mass were measured. Older women with low relative skeletal muscle mass had a lower daily intake of protein, iodine, polyunsaturated fatty acid (PUFA), Vit E, manganese, milk, fish, nuts and seeds (p < 0.05) compared to women with high relative skeletal muscle mass. The minimum required dietary protein intake for high relative skeletal muscle mass was 1.17 g/kg body mass/day (g/kg/d) (sensitivity: 0.68; specificity: 0.62). Women consuming ≥1.17 g/kg/d had a lower BMI (B = -3.9, p < 0.001) and fat mass (B = -7.8, p < 0.001), and a higher muscle quality (B = 0.06, p < 0.001). The data indicate that to maintain muscle mass and function, older women should consume ≥1.17 g/kg/d dietary protein, through a varied diet including milk, fish and nuts that also contain polyunsaturated fatty acid (PUFA) and micronutrients such as iodine, Vit E and manganese.

Fourteen days of smoking cessation improves muscle fatigue resistance and reverses markers of systemic inflammation.

Cigarette smoking has a negative effect on respiratory and skeletal muscle function and is a risk factor for various chronic diseases. To assess the effects of 14 days of smoking cessation on respiratory and skeletal muscle function, markers of inflammation and oxidative stress in humans. Spirometry, skeletal muscle function, circulating carboxyhaemoglobin levels, advanced glycation end products (AGEs), markers of oxidative stress and serum cytokines were measured in 38 non-smokers, and in 48 cigarette smokers at baseline and after 14 days of smoking cessation. Peak expiratory flow (p = 0.004) and forced expiratory volume in 1 s/forced vital capacity (p = 0.037) were lower in smokers compared to non-smokers but did not change significantly after smoking cessation. Smoking cessation increased skeletal muscle fatigue resistance (p < 0.001). Haemoglobin content, haematocrit, carboxyhaemoglobin, total AGEs, malondialdehyde, TNF-α, IL-2, IL-4, IL-6 and IL-10 (p < 0.05) levels were higher, and total antioxidant status (TAS), IL-12p70 and eosinophil numbers were lower (p < 0.05) in smokers. IL-4, IL-6, IL-10 and IL-12p70 had returned towards levels seen in non-smokers after 14 days smoking cessation (p < 0.05), and IL-2 and TNF-α showed a similar pattern but had not yet fully returned to levels seen in non-smokers. Haemoglobin, haematocrit, eosinophil count, AGEs, MDA and TAS did not significantly change with smoking cessation. Two weeks of smoking cessation was accompanied with an improved muscle fatigue resistance and a reduction in low-grade systemic inflammation in smokers.

A prolonged hiatus in postmenopausal HRT, does not nullify the therapy's positive impact on ageing related sarcopenia.

BACKGROUND: Previous work suggest a positive skeletal muscle effect of hormone replacement therapy (HRT) on skeletal muscle characteristics This study aimed to quantify any continued positive effect of HRT even after a sustained hiatus in treatment, controlling for two key muscle modulation hormones: Estradiol (E2) and Tri-iodo-thyronine (T3). METHOD AND FINDINGS: In 61 untrained women (18-78yrs) stratified as pre-menopausal, post-menopausal without (No_HRT) and post-menopausal with (Used_HRT) HRT history, body composition, physical activity, serum E2 and T3 were assessed by dual energy x-ray absorptiometry, Baecke questionnaire and ELISA. Gastrocnemius medialis (GM) and tibialis anterior (TA) electromyographic profiles (mean power frequency (mPowerF)), isometric plantar-flexion (PF) and dorsi-flexion (DF) maximum voluntary contraction (MVC), rate of torque development (RTD), isokinetic MVC and muscle volume, were assessed using surface electromyography, dynamometry and ultrasonography. Muscle quality was quantified as MVC per unit muscle size. E2 and E2:T3 ratio were significantly lower in postmenopausal participants, and were positively correlated with RTD even after controlling for adiposity and/or age. Pre-menopausal females had greater MVC in 8/8 PF and 2/5 DF (23.7-98.1%; P<0.001-0.049) strength measures compared to No_HRT, but only 6/8 PF (17.4-42.3%; P<0.001-0.046) strength measures compared to Used_HRT. Notably, Used_HRT had significant higher MVC in 7 PF MVC (30.0%-37.7%; P = 0.006-0.031) measures than No_HRT, while premenopausal and Used_HRT had similar uncorrected muscle size or quality. In addition, this cross-sectional data suggest an annual reduction in GM muscle volume corrected for intra-muscular fat by 1.3% in No_HRT and only 0.5% in Used_HRT. CONCLUSION: Even years after cessation of the therapy, a history of HRT is positively associated with negating the expected post-menopausal drop in muscle quantity and quality. Whilst mPowerF did not differ between groups, our work highlights positive associations between RTD against E2 and E2:T3. Notwithstanding our study limitation of single time point for blood sampling, our work is the first to illustrate an HRT attenuation of ageing-related decline in RTD. We infer from these data that high E2, even in the absence of high T3, may help maintain muscle contractile speed and quality. Thus our work is the first to points to markedly larger physiological reserves in women with a past history of HRT.

Static one-leg standing balance test as a screening tool for low muscle mass in healthy elderly women.

BACKGROUND: Identification of simple screening tools for detecting lower skeletal muscle mass may be beneficial for planning effective interventions in the elderly. AIMS: We aimed to (1) establish a threshold for one-leg standing balance test (OLST) time for low muscle mass, and (2) test the ability of that threshold to assess muscular impairments in a poor balance group. METHODS: Eyes-open OLST (maximum duration 30 s) was performed with right and left legs in 291 women (age 71 ± 6 years). OLST time was calculated as the sum of the OLST time of right and left legs. Fat-free mass (FFM), skeletal muscle mass (SMM), fat mass, biceps brachii and vastus lateralis sizes; handgrip strength (HGS), elbow flexion maximum torque (MVCEF) and knee extension maximum torque (MVCKE) were measured. Muscle quality was calculated as MVCKE/FFM and physical activity was assessed by questionnaire. Low muscle mass was defined as SMMrelative of 22.1%, a previously established threshold for pre-sarcopenia. RESULTS: The OLST threshold time to detect low muscle mass was 55 s (sensitivity: 0.63; specificity: 0.60). The poor balance group (OLST < 55 s) had higher fat mass (3.0%, p < 0.001), larger VL thickness (5.1%, p = 0.016), and lower HGS (- 10.2%, p < 0.001), MVCEF (- 8.2%, p = 0.003), MVCKE (- 9.5%, p = 0.012), MVCKE/FFM (- 11.0%, p = 0.004) and physical activity (- 8.0%, p = 0.024) compared to the normal balance group. While after adjusting age, the differences exist for HGS, fat mass and VL thickness only. DISCUSSION: An OLST threshold of 55 s calculated as the summed score from both legs discriminated pre-sarcopenic characteristics among active, community-dwelling older women with limited potential (sensitivity 0.63, specificity 0.60). CONCLUSION: OLST, which can be performed easily in community settings without the need for more complex muscle mass measurement, may help identify women at risk of developing sarcopenia.

Psychological parameters impact health-related quality of life in mental and physical domains in adults with muscular dystrophy.

The impacts of potentially treatable psychological parameters on quality of life are relatively unreported in adults with Facioscapulohumeral, Becker and Limb-girdle muscular dystrophy. The purpose of this study was to compare quality of life, psychological parameters, and physical function between adults with muscular dystrophy and controls, and to examine relationships among these parameters in muscular dystrophy. Twenty-one adults with muscular dystrophy (n = 7 Becker, n = 8 Facioscapulohumeral, n = 6 Limb-girdle) and ten age-matched controls participated. Outcome measures were health-related quality of life, depressive symptoms, trait anxiety, self-esteem, physical self-worth and six-minute walk distance. Quality of life scores were lower in the muscular dystrophy groups than the control (p < .05). Depressive symptoms had the greatest association with quality of life in the Mental Health domain (r= -0.89, p < .001). Depressive symptoms also had the most associations with quality of life (7 of 10 domains), followed by trait anxiety (6 of 10 domains), physical self-worth (5 of 10 domains), self-esteem (4 of 10 domains) and six-minute walk distance (3 of 10 domains). Psychological parameters and, to a lesser extent, physical function impact quality of life in muscular dystrophy. This study provides a rationale to include psychological assessment and treatment within muscular dystrophy healthcare.

The combined effects of obesity and ageing on skeletal muscle function and tendon properties in vivo in men.

PURPOSE: We investigated the combined impact of ageing and obesity on Achilles tendon (AT) properties in vivo in men, utilizing three classification methods of obesity. METHOD: Forty healthy, untrained men were categorised by age (young (18-49 years); older (50-80 years)), body mass index (BMI; normal weight (≥18.5-<25); overweight (≥25-<30); obese (≥30)), body fat% (normal adipose (<28%); high adiposity (≥28%)) and fat mass index (FMI; normal (3-6); excess fat (>6-9); high fat (>9). Assessment of body composition used dual-energy X-ray absorptiometry, gastrocnemius medialis (GM)/AT properties used dynamometry and ultrasonography and endocrine profiling used multiplex luminometry. RESULTS: Older men had lower total range of motion (ROM; -11%; P = 0.020), GM AT force (-29%; P < 0.001), stiffness (-18%; P = 0.041), Young's modulus (-22%; P = 0.011) and AT stress (-28%; P < 0.001). All three methods of classifying obesity revealed obesity to be associated with lower total ROM (P = 0.014-0.039). AT cross sectional area (CSA) was larger with higher BMI (P = 0.030). However, after controlling for age, higher BMI only tended to be associated with greater tendon stiffness (P = 0.074). Interestingly, both AT CSA and stiffness were positively correlated with body mass (r = 0.644 and r = 0.520) and BMI (r = 0.541 and r = 0.493) in the young but not older adults. Finally, negative relationships were observed between AT CSA and pro-inflammatory cytokines TNF-α, IL-6 and IL-1ß. CONCLUSIONS: This is the first study to provide evidence of positive adaptations in tendon stiffness and size in vivo resulting from increased mass and BMI in young but not older men, irrespective of obesity classification.

The Association of Multiple Gene Variants with Ageing Skeletal Muscle Phenotypes in Elderly Women.

There is a scarcity of studies that have investigated the role of multiple single nucleotide polymorphisms (SNPs) on a range of muscle phenotypes in an elderly population. The present study investigated the possible association of 24 SNPs with skeletal muscle phenotypes in 307 elderly Caucasian women (aged 60-91 years, 66.3 ± 11.3 kg). Skeletal muscle phenotypes included biceps brachii thickness, vastus lateralis cross-sectional areas, maximal hand grip strength, isometric knee extension and elbow flexion torque. Genotyping for 24 SNPs, chosen on their skeletal muscle structural or functional links, was conducted on DNA extracted from blood or saliva. Of the 24 SNPs, 10 were associated with at least one skeletal muscle phenotype. HIF1A rs11549465 was associated with three skeletal muscle phenotypes and PTK2 rs7460 and ACVR1B rs10783485 were each associated with two phenotypes. PTK2 rs7843014, COL1A1 rs1800012, CNTF rs1800169, NOS3 rs1799983, MSTN rs1805086, TRHR rs7832552 and FTO rs9939609 were each associated with one. Elderly women possessing favourable genotypes were 3.6-13.2% stronger and had 4.6-14.7% larger muscle than those with less favourable genotypes. These associations, together with future work involving a broader range of SNPs, may help identify individuals at particular risk of an age-associated loss of independence.

Associations of combined genetic and epigenetic scores with muscle size and muscle strength: a pilot study in older women.

BACKGROUND: Inter-individual variance in skeletal muscle is closely related to genetic architecture and epigenetic regulation. Studies have examined genetic and epigenetic relationships with characteristics of ageing muscle separately, while no study has combined both genetic and epigenetic profiles in ageing muscle research. The aim of this study was to evaluate the association between combined genetic and methylation scores and skeletal muscle phenotypes in older women. METHODS: Forty-eight older Caucasian women (aged 65-79 years) were included in this study. Biceps brachii thickness and vastus lateralis anatomical cross-sectional area (ACSAVL ) were measured by ultrasonography. Maximum isometric elbow flexion (MVCEF ) and knee extension (MVCKE ) torques were measured by a customized dynamometer. The muscle-driven genetic predisposition score (GPSSNP ) was calculated based on seven muscle-related single nucleotide polymorphisms (SNPs). DNA methylation levels of whole blood samples were analysed using Infinium MethylationEPIC BeadChip arrays. The DNA methylation score was calculated as a weighted sum of methylation levels of sarcopenia-driven CpG sites (MSSAR ) or an overall gene-wise methylation score (MSSNP , the mean methylation level of CpG sites located in muscle-related genes). Linear regression models were built to study genetic and epigenetic associations with muscle size and strength. Three models were built with both genetic and methylation scores: (1) MSSAR  + GPSSNP , (2) MSSNP  + GPSSNP , and (3) gene-wise combined scores which were calculated as the ratio of the SNP score to the mean methylation level of promoters in the corresponding gene. Additional models with only a genetic or methylation score were also built. All models were adjusted for age and BMI. RESULTS: MSSAR was negatively associated with ACSAVL , MVCEF , and MVCKE and explained 10.1%, 35.5%, and 40.1% of the variance, respectively. MSSAR explained more variance in these muscular phenotypes than GPSSNP , MSSNP , and models including both genetic and methylation scores. MSSNP and GPSSNP accounted for less than 8% and 5% of the variance in all muscular phenotypes, respectively. The genotype and methylation level of CNTF was positively related to MVCKE (P = 0.03) and explained 12.2% of the variance. The adjusted R2 and Akaike information criterion showed that models with only a MSSAR performed the best in explaining inter-individual variance in muscular phenotypes. CONCLUSIONS: Our results improve the understanding of inter-individual variance in muscular characteristics of older women and suggest a possible application of a sarcopenia-driven methylation score to muscle strength estimation in older women while the combination with a genetic score still needs to be further studied.

The Genetic Effect on Muscular Changes in an Older Population: A Follow-Up Study after One-Year Cessation of Structured Training.

Older adults lose muscle mass and strength at different speeds after the cessation of physical exercise, which might be genotype related. This study aimed to explore the genetic association with changes in muscle mass and strength one year after the cessation of structured training in an older population. Participants (n = 113, aged between 61 and 81 years) who performed one-year of combined fitness (n = 44) or whole-body vibration (n = 69) training were assessed one year after the cessation of the training. Whole-body skeletal muscle mass and knee strength were measured. Data-driven genetic predisposition scores (GPSs) were calculated and analysed in a general linear model with sex, age, body mass index and post-training values of skeletal muscle mass or muscle strength as covariates. Forty-six single nucleotide polymorphisms (SNPs) from an initial 170 muscle-related SNPs were identified as being significantly linked to muscular changes after cessation. Data-driven GPSs and over time muscular changes were significantly related (p < 0.01). Participants with higher GPSs had less muscular declines during the cessation period while data-driven GPSs accounted for 26-37% of the phenotypic variances. Our findings indicate that the loss of training benefits in older adults is partially genotype related.