Relationship between lifestyle differences and sarcopenia, muscle mass in patients with rheumatoid arthritis: Comparison of metropolitan and country areas.

Objectives: Differences in living environments and lifestyle affect physical activity and the sarcopenia rate in rheumatoid arthritis (RA) patients. This study aimed to investigate the effects of differences in living environment and lifestyle by area of residence on the prevalence rate of sarcopenia, physical activity, and body composition in RA patients.

Methods: Patients were divided into metropolitan (n = 77) and country (n = 67) groups by area of residence. Both groups were age- and sex-matched. Body composition was evaluated by a body composition analyzer, and the prevalence of sarcopenia was compared. Physical activity was assessed using the international physical activity questionnaire. Questions regarding means of commuting to hospital, family structure, and occupation type were asked to evaluate living environment and lifestyle. Associations between sarcopenia and lifestyle were investigated by univariate and multivariate analyses.

Results: There was no significant difference in the prevalence of sarcopenia between the metropolitan (26.0 %) and country (34.3 %) groups. Muscle mass was significantly higher in the metropolitan group (34.6 kg) than in the country group (32.9 kg; p = 0.026). Transportation physical activity was significantly higher in the metropolitan group (693 METs⋅Min/Week) than in the country group (0 METs⋅Min/Week; p < 0.001). Multivariate logistic regression analysis, adjusted for age, disease duration, DAS28-ESR,mHAQ, and glucocorticoid usage, identified only unemployment as an independent factor associated with sarcopenia (OR: 3.40, 95%CI: 1.10-10.4, p = 0.032).

Conclusions: RA patients living in metropolitan areas had significantly higher muscle mass than those living in the countryside. However, there was no significant difference in the prevalence of sarcopenia. Unemployment was identified as an independent factor associated with sarcopenia.