Are current definitions of sarcopenia applicable for older Chinese adults?

This study aims to explore whether the current definitions of sarcopenia are applicable to the older Chinese population. Participants were 783 Chinese adults recruited from four regions in Mainland China: Jinan, Guangzhou, Xi'an, and Chengdu. Body composition was measured by dual energy x-ray absorptiometry. Handgrip strength, body weight, and height were measured by trained technicians, and demographic data were collected through questionnaires. Relative appendicular skeletal muscle, skeletal muscle index (SMI=100 × skeletal muscle mass/ body mass) and residuals methods were applied to identify sarcopenia. Compared with young adults, no significant decrease was found in the relative appendicular skeletal muscle (ASM/height2) in older adults. If the criterion of two standard deviations below the mean value of ASM/height2 in young adults is used, none of older adults in this study could be diagnosed with sarcopenia. In addition, compared with the ASM/height2 and residuals methods, SMI shows higher discriminating power in the identifying persons with low handgrip strength. The data suggest that ASM/height2 method may not be appropriate for diagnosis of sarcopenia in Chinese population. However, whether SMI is a better choice remains inconclusive. Prospective studies are needed to clearly define sarcopenia in Chinese population.