Differences in body composition and grip between Japanese and Thai older people living in Thailand

Background Age-related muscle mass loss is one of the main risk factors for osteoporosis and fractures among older people. Thus, prevention of muscle mass loss in older people is an important issue. We examined ethnic group-related differences in body composition and grip strength among older people living in the same area. Methods We measured body composition and grip strength among local Thai older people living in Chiang Mai Province, as well as in Japanese older people who emigrated to Chiang Mai Province in their retirement. A self-reported questionnaire regarding socio-demographic status was also administered. Measurement items were averaged and compared by sex and ethnic group. Questionnaire items were also categorized by sex and ethnic group. Results A total of 119 older people participated, including 47 Japanese participants (26 men, 21 women) and 72 Thai participants (16 men, 56 women). The average age of Japanese participants was 71.1 years (standard deviation: 4.89), and the average age of Thai participants was 68.8 years (standard deviation: 5.61). Significant differences between ethnic groups were found in percentage of body fat in women (Japanese average: 32.9% vs. Thai average: 37.6%, p < 0.05), skeletal muscle mass index (SMI) in men (Japanese average: 7.85 kg/m2 vs. Thai average: 7.31 kg/m2, p < 0.05) and average grip strength in men (Japanese: 35.1 kg vs. Thai: 30.7 kg, p < 0.05). Conclusions Our preliminary results suggest that Thai older people, particularly men, are weaker than Japanese older people. Decreased muscle mass is directly responsible for functional impairment, involving loss of strength, increased likelihood of falls, and loss of autonomy. Preventing muscle weakness among older people is important. In future studies, we plan to analyze and clarify the differences between Thai and Japanese older people to identify effective methods to prevent muscle mass decreases. Key messages There were significant differences in average % body fat between older Japanese and Thai women. There were significant differences in average SMI and grip strength between older Japanese and Thai men.