Associations of Moderate-to-Vigorous Physical Activity with Obesity and Low Muscle Mass Among Postmenopausal Chinese Women: A Cross-Sectional Study.

OBJECTIVE: To examine the associations of guideline-based moderate-to-vigorous physical activity (MVPA) levels with obesity and low muscle mass in postmenopausal Chinese women. METHODS: Cross-sectional data from 1578 postmenopausal women aged ≥45 years in Jiangsu, China were analyzed. Obesity was defined as body fat percentage ≥30% according to Chinese criteria, and low muscle mass as appendicular skeletal muscle index <5.7 kg/m2 according to the Asian Working Group for Sarcopenia 2019 criteria. Both were assessed using bioelectrical impedance. Physical activity was assessed using the International Physical Activity Questionnaire-Short Form. MVPA was calculated and categorized according to World Health Organization (WHO) physical activity recommendations (<150, 150-299, and ≥300 min/week). Multivariable logistic regression models were used to examine associations between MVPA levels and study outcomes. RESULTS: 27.7% (n=437) of women had obesity and 7.5% (n=118) had low muscle mass. Compared with women reporting <150 min/week of MVPA, those reporting 150-299 min/week and ≥300 min/week had lower odds of obesity. In fully adjusted models, the odds ratios were 0.55 (95% CI: 0.35-0.86) and 0.42 (95% CI: 0.29-0.61), respectively. The corresponding odds ratios for low muscle mass were 0.21 (95% CI: 0.07-0.68) and 0.30 (95% CI: 0.14-0.66). CONCLUSION: Higher MVPA was associated with lower odds of obesity. Inverse associations were also observed for low muscle mass, although this finding warrants cautious interpretation.