2026 Volume 46 Pages 355-365
Objective: To clarify the prevalence of low skeletal muscle mass in the extremities and lower limbs and its association with physical activity among male workers living in a rural area of Japan.
Methods: A cross-sectional analysis of the A Cohort Study was conducted. Skeletal muscle mass was assessed using a bioelectrical impedance analyzer, and weekly physical activity was evaluated. Binary logistic regression analysis was performed to examine the association between physical activity and low skeletal muscle mass index (SMI).
Results: SMI in the lower limbs was lowest among participants in their 50s and was significantly lower compared to those in their 40s. Among the 688 subjects analyzed, 89 and 110 had low SMI in the extremities and the lower limbs, respectively. Total physical activity during transportation and leisure time was significantly associated with low SMI. In particular, the adjusted odds ratios for low SMI in the lower limbs were 0.870 (95% CI: 0.800–0.946) for transportation-related physical activity and 0.963 (95% CI: 0.941–0.986) for leisure-time physical activity, indicating stronger associations than those observed for low SMI in the extremities.
Conclusion: These findings confirm the importance of evaluating lower-limb SMI among male workers living in rural areas and suggest that increasing physical activity during transportation and leisure time may help prevent low skeletal muscle mass.
