Six-week Aerobic Exercise Improves Oxidative Damage of Skeletal Muscles and Promotes Myokine Production in Atherosclerotic Mice / 中国生物化学与分子生物学报

Atherosclerosis involving peripheral arteries can cause skeletal muscle lesions, in which oxidative damage is an important manifestation, and atherosclerosis also reduces the production and secretion of beneficial myokines. Irisin, musclin and β-aminoisobutyric acid (BAIBA) are thought to be involved in improving atherosclerosis. However, the molecular mechanism of atherosclerosis-induced skeletal muscle lesions and the effects of aerobic exercise training on the oxidative damage of skeletal muscle and myokine production remain unclear. In this study, apolipoprotein E knockout (ApoE

Muscle Strength Explains the Protective Effect of Physical Activity against COVID-19 Hospitalization among Adults aged 50 Years and Older

ObjectivesPhysical activity has been proposed as a protective factor for COVID-19 hospitalization. However, the mechanisms underlying this association are unclear. Here, we examined the association between physical activity and COVID-19 hospitalization and whether this relationship was explained by other risk factors for severe COVID-19. MethodWe used data from adults aged 50 years and older from the Survey of Health, Ageing and Retirement in Europe. The outcome was self-reported hospitalization due to COVID-19 measured before August 2020. The main exposure was usual physical activity, self-reported between 2004 and 2017. Data were analyzed using logistic regression models. ResultsAmong the 3139 participants included in the study (69.3 {+/-} 8.5 years, 1763 women), 266 were tested positive for COVID-19 and 66 were hospitalized. Results showed that individuals who engaged in physical activity more than once a week had lower odds of COVID-19 hospitalization than individuals who hardly ever or never engaged in physical activity (odds ratios = 0.41, 95% confidence interval = 0.22-0.74, p = .004). This association between physical activity and COVID-19 hospitalization was explained by muscle strength, but not by other risk factors. ConclusionThese findings suggest that, after 50 years of age, engaging in physical activity more than once a week is associated with lower odds of COVID-19 hospitalization. The protective effect of physical activity on COVID-19 hospitalization is explained by muscle strength.

Muscle strength is associated with COVID-19 hospitalization in adults 50 years of age and older

BackgroundWeak muscle strength has been associated with a wide range of adverse health outcomes. Yet, whether individuals with weaker muscle strength are more at risk for hospitalization due to severe COVID-19 is still unclear. The objective of this study was to investigate the independent association between muscle strength and COVID-19 hospitalization. MethodsData from adults 50 years of age or older were analyzed using logistic models adjusted for several chronic conditions, body-mass index, age, and sex. Hand-grip strength was repeatedly measured between 2004 and 2017 using a handheld dynamometer. COVID-19 hospitalization during the lockdown was self reported in summer 2020 and was used as an indicator of COVID-19 severity. ResultsThe study was based on the Survey of Health, Ageing and Retirement in Europe (SHARE) and included 3600 older adults (68.8 {+/-} 8.8 years, 2044 females), amongst whom 316 were tested positive for the severe acute respiratory syndrome coronavirus 2 (8.8%) and 83 (2.3 %) were hospitalized due to COVID-19. Results showed that higher grip strength was associated with a lower risk of COVID-19 hospitalization (adjusted odds ratio [OR] per increase of 1 standard deviation in grip strength = .64, 95% confidence interval [95% CI] = .45-.87, p = .015). Results also showed that age (OR for a 10-year period = 1.70, 95% CI = 1.32-2.20, p < .001) and obesity (OR = 2.01, 95% CI = 1.00-3.69, p = .025) were associated with higher risk of COVID-19 hospitalization. Sensitivity analyses using different measurements of grip strength as well as robustness analyses based on rare-events logistic regression and a different sample of participants (i.e., COVID-19 patients) were consistent with the main results. ConclusionMuscle strength is an independent risk factor for COVID-19 severity in adults 50 years of age or older.

Effects of COVID-19 lockdown on heart rate variability

IntroductionStrict lockdown rules were imposed to the French population from 17 March to 11 May 2020, which may result in limited possibilities of physical activity, modified psychological and health states. This report is focused on HRV parameters kinetics before, during and after this lockdown period. Methods95 participants were included in this study, who underwent regular orthostatic tests (a 5-minute supine followed by a 5-minute standing recording of heart rate (HR)) on a regular basis before, during and after the lockdown (BSL, CFN and RCV, respectively). HR, power in low- and high-frequency bands (LF, HF, respectively) and root mean square of the successive differences (RMSSD) were computed for each orthostatic test, and for each positions. Subjective well-being was assessed on a 0-10 visual analogic scale (VAS). ResultsOut of the 95 participants, 19 (WB+) reported an improved well-being (i.e., increase >2 in VAS score) during CFN, contradictory to the 76 other participants (WB-). There was an increase in HR and a decrease in RMSSD when measured supine in CFN and RCV, compared to BSL in WB-, whilst opposite results were found in WB+ (i.e. decrease in HR and increase in RMSSD in CFN and RCV; increase in LF and HF in RCV). There was a moderate significant correlation between VAS and HR, RMSSD, HF, respectively, in the supine position; the higher the VAS score (i.e., subjective well-being), the higher the RMSSD and HF and the lower the HR. In standing position, HRV parameters were not modified during CFN. ConclusionThe strict COVID-19 lockdown likely had opposite effects on French population as 20% of participants improved parasympathetic activation (RMSSD, HF) and rated positively this period, whilst 80% showed altered responses and deteriorated well-being. The changes in HRV parameters during and after the lockdown period were in line with subjective well-being responses. These results confirmed the usefulness of HRV as a non-invasive means for monitoring well-being and health in the general population.