The Relationship between Skeletal Muscle Mass and Bone Mass at Different Sites in Older Adults

Effect of COVID-19 pandemic on bioimpedance health indicators in young adults

OBJECTIVES

Herein, we investigate the relationships between the COVID-19 pandemic and overcoming the virus, and its effects on body composition parameters in young adults from Slovakia.

METHODS

We assessed 773 adults aged 18 to 30 years in pandemic-status sub-groups. Individual lifestyles and overcoming the COVID-19 effects were evaluated by a detailed questionnaire, and body composition parameters were analyzed using the InBody 770 bioimpedance analyzer.

RESULTS

Statistically significant lower values were observed in the male group during the pandemic for the following parameters; proteins and minerals, fat free mass (FFM), skeletal muscle mass (SMM), lean body mass (LBM) and its values in the right and left arm and trunk, total body water (TBW) and its values in the right and left arm and trunk, body cell mass (BCM), basal metabolic rate (BMR) and phase angle (PA). The regression analysis confirmed the negative pandemic effect and the negative impact of COVID-19 on men in the following parameters: proteins (p = .027 for pandemic and p = .005 for COVID-19), FFM (p = .023 for pandemic and p = .005 for COVID-19), LBM (p = .022 for pandemic and p = .004 for COVID-19), SMM (p = .028 for pandemic and p = .005 for COVID-19), TBW (p = .020 for pandemic and p = .004 for COVID-19), BMR (p = .024 for pandemic and p = .005 for COVID-19) and PA (p = .009 for pandemic). Physical activity was a further significant predictor in men for all the above parameters.

CONCLUSIONS

We observed significantly lower body composition parameters associated with fat free mass in young adult men during the pandemic than before it. However, future research is warranted to determine if these effects have long-term significance.

Association between normal-weight obesity and bone mineral density in older Korean adults: A population-based cross-sectional study

The effects of normal-weight obesity, which is defined as having a high level of body fat despite a normal body mass index, on the health of bones in older adults are poorly understood. This cross-sectional study examined the relationship between normal-weight obesity and bone mineral density in Korean adults aged 50 years or more (2815 men and 2744 women) from the 2008-2011 Korea National Health and Nutrition Examination Surveys. Between the ages of 50 and 69 years, individuals with normal-weight obesity had a higher risk of low bone mineral density (odds ratio = 1.596, 95 % confidence interval = 1.189-2.141, p = 0.002) compared with individuals with normal-weight non-obesity. However, no significant association between normal-weight obesity and bone mineral density was observed among people between the ages of 70 and 89 years. The study findings support the clinical significance of normal-weight obesity as a proxy biomarker to identify in primary care settings people who are at increased risk of developing osteoporosis at an early stage of aging.

Eldecalcitol prevents muscle loss and osteoporosis in disuse muscle atrophy via NF-κB signaling in mice

We investigated the effect of eldecalcitol on disuse muscle atrophy. C57BL/6J male mice aged 6 weeks were randomly assigned to control, tail suspension (TS), and TS-eldecalcitol-treated groups and were injected intraperitoneally twice a week with either vehicle (control and TS) or eldecalcitol at 3.5 or 5 ng for 3 weeks. Grip strength and muscle weights of the gastrocnemius (GAS), tibialis anterior (TA), and soleus (SOL) were determined. Oxidative stress was evaluated by malondialdehyde, superoxide dismutase, glutathione peroxidase, and catalase. Bone microarchitecture was analyzed using microcomputed tomography. The effect of eldecalcitol on C2C12 myoblasts was analyzed by measuring myofibrillar protein MHC and the atrophy markers Atrogin-1 and MuRF-1 using immunofluorescence. The influence of eldecalcitol on NF-κB signaling pathway and vitamin D receptor (VDR) was assessed through immunofluorescence, (co)-immunoprecipitation, and VDR knockdown studies. Eldecalcitol increased grip strength (P < 0.01) and restored muscle loss in GAS, TA, and SOL (P < 0.05 to P < 0.001) induced by TS. An improvement was noted in bone mineral density and bone architecture in the eldecalcitol group. The impaired oxidative defense system was restored by eldecalcitol (P < 0.05 to P < 0.01 vs. TS). Eldecalcitol (10 nM) significantly inhibited the expression of MuRF-1 (P < 0.001) and Atrogin-1 (P < 0.01), increased the diameter of myotubes (P < 0.05), inhibited the expression of P65 and P52 components of NF-κB and P65 nuclear location, thereby inhibiting NF-κB signaling. Eldecalcitol promoted VDR binding to P65 and P52. VDR signaling is required for eldecalcitol-mediated anti-atrophy effects. In conclusion, eldecalcitol exerted its beneficial effects on disuse-induced muscle atrophy via NF-κB inhibition.

Correlations between Mental Health, Physical Activity, and Body Composition in American College Students after the COVID-19 Pandemic Lockdown

Restrictions associated with the COVID-19 pandemic had forced American college students to significantly reduce their daily energy expenditure and increase their sedentary behaviors, thus presumably increasing mental health symptoms, decreasing physical activity levels, and enhancing the promotion of unhealthy eating habits. This study aimed to explore the correlations between mental health symptoms, physical activity levels, and body composition in college students in the years following the pandemic, focusing on the lingering effects of lockdown measures. American college students completed pre-existing, well-validated surveys for both mental health (Hospital Anxiety and Depression Scale) and physical activity (International Physical Activity Questionnaire-Long Form). Body composition was assessed in person with the use of an Inbody 570 device. Of the 90 American college students (M age = 22.52 ± 4.54, 50 females) who participated in this study, depressive and anxious symptom scores consistent with heightened symptomatology were reported by 58% of the participants (N = 52), moderate borderline symptomatology by 17% (N = 15), and asymptomatology by 25% (N = 23). In regard to physical activity, 79% (N = 71) of the students were highly physically active, 18% (N = 16) were moderately active, and 3% (N = 3) reported low levels of physical activity. Additionally, 46% (N = 41) of the students maintained an unhealthy body fat percentage based on the World Health Organization recommendations. Strong, significant relationships were found between anxiety and depression symptomatology and body fat percentage (positive correlation, p = 0.003) and between anxiety and depression symptomatology and skeletal muscle mass (negative correlation, p = 0.015), with said symptomatology increasing with added body fat and decreasing with added skeletal muscle mass. The COVID-19 pandemic lockdown restrictions affected American college students through an increase in mental health symptomatology and a deterioration in overall body composition.