Sarcopenia and sarcopenic obesity among men aged 80 years and older in Beijing: prevalence and its association with functional performance.

AIM: Sarcopenia and sarcopenic obesity are significant associative factors for functional impairment related to aging. The main aim of the present study was to investigate the prevalence of sarcopenia and sarcopenic obesity, and their associations with functional status among men aged 80 years and older in Beijing.

METHODS: A total of 75 young healthy volunteers, and 101 older men aged 80 years and older participated in the present study. Demographic characteristics, anthropometry, skeletal muscle mass measured by dual X-ray absorptiometry (DXA), 6-m gait speed and handgrip strength were collected. Relative appendicular skeletal muscle index (RASM) and percentage skeletal muscle index (SMI) were obtained.

RESULTS: Overall, the prevalence of sarcopenia was 45.7% by using RASM. By the weight-adjusted skeletal muscle index definition (SMI), the prevalence of sarcopenia was 53.2%. The prevalence of sarcopenic obesity was lower by using RASM than SMI (4.9% vs 11.5%, P < 0.05). When we compared the sarcopenia prevalence (%) in obese participants, it was also remarkably lower by using RASM (40.0%) than SMI (95.0%). By using either RASM or SMI, gait speed was of no significant difference among the pure sarcopenia group, pure obese group and sarcopenic obesity group (0.76 ± 0.27 vs 0.82 ± 0.37 vs 0.82 ± 0.27 m/s, P > 0.05, by RASM; 0.75 ± 0.25 vs 0.92 ± 0.27 vs 0.82 ± 0.35 m/s, P > 0.05 by SMI), respectively. Multiple linear regression analyses showed that thigh skeletal muscle mass was positively correlated with gait speed independently (β = 0.221, P = 0.011), and total body fat (β = -0.216, P = 0.002) and age (β = -0.524, P = 0.000) were negatively correlated with gait speed independently.

CONCLUSIONS: The prevalence of sarcopenia is high either based on RASM or SMI among Chinese men aged 80 years and older. Functional limitations were significantly associated with older age, skeletal muscle mass and total body fat.