The role of muscle mass and body fat on disability among older adults: A cross-national analysis.

Background: The aim of this study was to evaluate the association of sarcopenia and sarcopenic obesity with disability among older adults (= 65 years old) in nine high-, middle- and low-income countries from Asia, Africa, Europe, and Latin America. Methods: Data were available for 53,289 people aged = 18 years who participated in the Collaborative Research on Ageing in Europe (COURAGE) survey conducted in Finland, Poland, and Spain, and the WHO Study on global AGEing and adult health (SAGE) survey conducted in China, Ghana, India, Mexico, Russia, and South Africa, between 2007 and 2012. Skeletal muscle mass, skeletal muscle mass index, and percent body fat were calculated with specific population formulas. Sarcopenia and sarcopenic obesity were defined by specific cut-offs used in previous studies. Disability was assessed with the WHODAS 2.0 score (range 0-100) with higher scores corresponding to higher levels of disability. Multivariable linear regression analysis was conducted with disability as the outcome. Results: The analytical sample consisted of 18,363 people (males; n = 8116, females; n = 10247) aged = 65 years with mean (SD) age 72.9 (11.1) years. In the fully-adjusted overall analysis, sarcopenic obesity was associated with greater levels of disability [b-coefficient 3.01 (95% CI 1.14-4.88)]. In terms of country-wise analyses, sarcopenia was associated with higher WHODAS 2.0 scores in China [b-coefficient 4.56 (95% CI: 3.25-5.87)], Poland [b-coefficient 6.66 (95% CI: 2.17-11.14)], Russia [b-coefficient 5.60 (95% CI: 2.03-9.16)], and South Africa [b-coefficient 7.75 (95% CI: 1.56-13.94)]. Conclusions: Prevention of muscle mass decline may contribute to reducing the global burden of disability. [ABSTRACT FROM AUTHOR]