#Circadian Clock Interaction with HIF1α Mediates Oxygenic Metabolism and Anaerobic Glycolysis in Skeletal #Muscle

http://www.cell.com/cell-metabolism/fulltext/S1550-4131(16)30490-9

Finally, induction of clock and HIF1α target genes in response to strenuous exercise varied according to the time of day in wild-type mice. Collectively, our results reveal bidirectional interactions between circadian and HIF pathways that influence metabolic adaptation to hypoxia

#Smoking-induced Skeletal #Muscle Dysfunction. American Journal of Respiratory and Critical Care Medicine http://www.atsjournals.org/doi/10.1164/rccm.201410-1830PP Smoking is the most important risk factor for the development of chronic obstructive pulmonary disease (COPD). Patients with COPD commonly suffer from skeletal muscle dysfunction, and it has been suggested that cigarette smoke exposure contributes to the development of skeletal muscle dysfunction even before overt pulmonary pathology. This review summarizes the evidence that muscles of nonsymptomatic smokers are weaker and less fatigue resistant than those of nonsmokers. Although physical inactivity of many smokers contributes to some alterations observed in skeletal muscle, exposure to cigarette smoke per se can also induce skeletal muscle dysfunction. Cigarette smoke constituents and systemic inflammatory mediators enhance proteolysis and inhibit protein synthesis, leading to loss of muscle mass. Reduced skeletal muscle contractile endurance in smokers may result from impaired oxygen delivery to the mitochondria and ability of the mitochondria to generate ATP due to interaction of carbon monoxide with hemoglobin, myoglobin, and components of the respiratory chain. Besides hampering contractile function, smoking may have immediate beneficial effects on motor skills, which are attributable to nicotine. In contrast to pulmonary pathology, many of the effects of smoking on skeletal muscle are most likely reversible by smoking cessation.

Bmal1 function in skeletal #muscle regulates #sleep
https://elifesciences.org/articles/26557

Sleep loss can severely impair the ability to perform, yet the ability to recover from sleep loss is not well understood. Sleep regulatory processes are assumed to lie exclusively within the brain mainly due to the strong behavioral manifestations of sleep. Whole-body knockout of the circadian clock gene Bmal1 in mice affects several aspects of sleep, however, the cells/tissues responsible are unknown.

..We also found that overexpression of skeletal-muscle Bmal1 reduced the recovery response to sleep loss.

Together, these findings demonstrate that Bmal1 expression in skeletal muscle is both necessary and sufficient to regulate total sleep amount and reveal that critical components of normal sleep regulation occur in muscle.

Changes in #liver function and body composition by direct-acting antiviral therapy for hepatitis #C virus infection http://onlinelibrary.wiley.com/doi/10.1111/hepr.12999/full

Management of low skeletal #muscle mass (LSM) is a very important topic since LSM affects patient mortality in liver diseases. Changes in body composition are unexplored in chronic hepatitis C virus (HCV) patients, including those with liver cirrhosis, who receive direct-acting antiviral (DAA) therapy. Body composition measurements and liver function tests were performed before and after DAA therapy Serum albumin (Alb) levels were significantly increased at 48 weeks post DAA therapy, especially in patients with LSM. Skeletal muscle mass index (SMI) was significantly increased after DAA therapy (at 24 weeks and 48 weeks post DAA therapy) in patients with LSM (p<0.05). An increase in SMI was associated with an increase in body weight or a decrease in VFA.

Conclusions

We continuously measured body composition in HCV infected patients who received DAA therapy and found that skeletal muscle mass was significantly increased, associated with an elevation of serum Alb levels and/or body weight or reduction in VFA, but only in patients who presented with LSM before DAA therapy

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Effect of In-Bed Leg Cycling and Electrical Stimulation of the Quadriceps on Global #Muscle #Strength in Critically Ill Adults

https://jamanetwork.com/journals/jama/article-abstract/2688570


Among 314 randomized patients, 312 (mean age, 66 years; women, 36%; receiving mechanical ventilation at study inclusion, 78%) completed the study and were included in the analysis. The median global Medical Research Council score at ICU discharge was 48 (interquartile range IQR, 29 to 58) in the intervention group and 51 (IQR, 37 to 58) in the usual care group (median difference, −3.0 95% CI, −7.0 to 2.8; P = .28). The ICU Mobility Scale score at ICU discharge was 6 (IQR, 3 to 9) in both groups (median difference, 0 95% CI, −1 to 2; P = .52). The median number of ventilator-free days at day 28 was 21 (IQR, 6 to 25) in the intervention group and 22 (IQR, 10 to 25) in the usual care group (median difference, 1 95% CI, −2 to 3; P = .24). Clinically significant events occurred during mobilization sessions in 7 patients (4.4%) in the intervention group and in 9 patients (5.8%) in the usual care group. There were no significant between-group differences in the outcomes assessed at 6 months.

Conclusions and Relevance In this single-center randomized clinical trial involving patients admitted to the ICU, adding early in-bed leg cycling exercises and electrical stimulation of the quadriceps muscles to a standardized early rehabilitation program did not improve global muscle strength at discharge from the ICU.

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Association Between #Hormone Therapy and #Muscle Mass in Postmenopausal Women
A Systematic Review and Meta-analysis

https://jamanetwork.com/journals/jamanetworkopen/fullarticle/2749051

Hormone therapy (HT) has been suggested for protection against age-related muscle weakness in women. However, the potential for HT-associated health risks necessitates a better understanding of the direction and magnitude of the association between HT and health outcomes, such as lean body mass (LBM).

..The results were unchanged when stratified based on treatment type and dosage, duration of follow-up, time since menopause, study quality, and type of LBM measurement, with HT users losing between 0.06 kg more to 0.20 kg less LBM compared with control participants for all strata. The quality of evidence based on GRADE was low..

Conclusions and Relevance This systematic review and meta-analysis did not show a significant beneficial or detrimental association of HT with muscle mass. Although muscle retention in aging women is of crucial importance, these findings suggest that interventions other than HT should be explored.

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Skeletal #muscle mass in relation to 10 year #cardiovascular disease incidence among middle aged and older adults: the ATTICA study

Skeletal muscle mass (SMM) is inversely associated with cardiometabolic health and the ageing process. The aim of the present work was to evaluate the relation between SMM and 10 year cardiovascular disease (CVD) incidence, among CVD-free adults 45+ years old.

The 10 year CVD incidence increased significantly across the baseline SMI tertiles (p<0.001). Baseline SMM showed a significant inverse association with the 10 year CVD incidence (HR 0.06, 95% CI 0.005 to 0.78), even after adjusting for various confounders. Additionally, participants in the highest SMM tertile had 81% (95% CI 0.04 to 0.85) lower risk for a CVD event as compared with those in the lowest SMM tertile.

Conclusions The presented findings support the importance of SMM evaluation in the prediction of long-term CVD risk among adults 45+ years old without pre-existing CVD. Preservation of SMM may contribute to CVD health.

https://jech.bmj.com/content/early/2019/10/16/jech-2019-212268

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Associations between Skeletal #Muscle and #Myocardium in Aging: A Syndrome of “Cardio‐Sarcopenia”?

..We hypothesize that among aging adults with sarcopenia, alterations in myocardial structure and/or function may exist, resulting in a syndrome of “cardio‐sarcopenia.”

..Participants with sarcopenia had smaller left ventricular (LV) sizes (lower LV internal diameter end diastole (4.1 ± .7 vs 4.5 ± .6 cm; P < .0001), lower LV internal diameter end systole (2.3 ± .5 vs 2.5 ± .4 cm; P = .010), lower LV posterior wall end diastole (.7 ± .1 vs .8 ± .1 cm; P = .0036), and lower LV posterior wall end systole (1.4 ± .3 vs 1.5 ± .2 cm; P = .0031). Sarcopenic participants also had lower LV mass (106 ± 35 vs 126 ± 53; P = .0014) and lower left atrial (LA) volume (33 ± 13 vs 36 ± 13; P = .033). Adjusting for age and diabetes mellitus, skeletal muscle mass was associated with LV diameter (β = .06; 95% confidence interval [CI] = .03‐.09; P < .0001), LV mass (β = 4.04; 95% CI = 1.78‐6.29; P = .001), LA diameter (β = .05; 95% CI = .01‐.09; P = .007), and LA volume (β = 1.26; 95% CI = .38‐2.13; P = .005). A positive linear correlation was observed between LV mass and handgrip strength (r = .25; P < .0001).

Conclusion
Among a community sample of older adults with preserved heart function, sarcopenia is associated with reductions in LV and LA sizes. Skeletal muscle mass was independently associated with specific indices of myocardial structure.

https://bit.ly/2E45aFw

#Potato Protein Isolate Stimulates #Muscle Protein Synthesis at Rest and with Resistance Exercise in Young Women
https://2medical.news/2020/05/24/potato-protein-isolate-stimulates-muscle-protein-synthesis-at-rest-and-with-resistance-exercise-in-young-women/

Skeletal muscle myofibrillar protein synthesis (MPS) increases in response to protein feeding and to resistance exercise (RE), where each stimuli acts synergistically when combined. The efficacy of plant proteins such as potato protein (PP) isolate to stimulate MPS is unknown. We aimed to determine the effects of PP ingestion on daily MPS with and without RE in healthy women. In a single blind, parallel-group design, …

Effectiveness of pelvic floor #muscle training with and without electromyographic biofeedback for urinary #incontinence in women: multicentre randomised controlled trial
https://2medical.news/2020/10/21/effectiveness-of-pelvic-floor-muscle-training-with-and-without-electromyographic-biofeedback-for-urinary-incontinence-in-women-multicentre-randomised-controlled-trial/

To assess the effectiveness of pelvic floor muscle training (PFMT) plus electromyographic biofeedback or PFMT alone for stress or mixed urinary incontinence in women.. Mean ICIQ-UI SF scores at 24 months were 8.2 (SD 5.1, n=225) in the biofeedback PFMT group and 8.5 (SD 4.9, n=235) in the PFMT group (mean difference −0.09, 95% confidence interval −0.92 to 0.75, P=0.84). Biofeedback PFMT had similar costs …

#Statin treatment and #muscle symptoms: series of randomised, placebo controlled n-of-1 trials
https://2medical.news/2021/02/26/statin-treatment-and-muscle-symptoms-series-of-randomised-placebo-controlled-n-of-1-trials/

To establish the effect of statins on muscle symptoms in people who had previously reported muscle symptoms when taking statins. Design Series of randomised, placebo controlled n-of-1 trials. Setting Primary care across 50 sites in the United Kingdom, December 2016 to April 2018. Participants 200 participants who had recently stopped or were considering stopping treatment with statins because of muscle symptoms. Interventions Participants were randomised …

Low #muscle mass in #older adults and mortality: A systematic review and meta-analysis

https://2medical.news/2021/07/02/low-muscle-mass-in-older-adults-and-mortality-a-systematic-review-and-meta-analysis/

Distribution of dietary #protein intake in daily meals influences skeletal #muscle hypertrophy via the muscle clock

https://2medical.news/2021/07/29/distribution-of-dietary-protein-intake-in-daily-meals-influences-skeletal-muscle-hypertrophy-via-the-muscle-clock/

#Dysbiosis of the gut microbiome impairs mouse skeletal #muscle adaptation to exercise

https://2medical.news/2021/10/02/dysbiosis-of-the-gut-microbiome-impairs-mouse-skeletal-muscle-adaptation-to-exercise/

Prospective Associations of Different Combinations of #Aerobic and #Muscle-Strengthening Activity With All-Cause, #Cardiovascular, and Cancer Mortality

https://2medical.news/2023/08/19/prospective-associations-of-different-combinations-of-aerobic-and-muscle-strengthening-activity-with-all-cause-cardiovascular-and-cancer-mortality/