Age-related changes of skeletal muscle mass and strength among Italian and Taiwanese older people: Results from the Milan EXPO 2015 survey and the I-Lan Longitudinal Aging Study.

BACKGROUND: Muscle mass and strength ineluctably decline with advancing age. Yet, the impact of ethnicity on the pattern of changes and their magnitude is unclear. The aims of the present study were to analyze age- and gender-specific changes in measures of muscle mass and strength among community-living persons and to identify differences between Caucasian and Asian participants.

METHODS: The Italian survey ("Longevity Check-up"), conducted during Milan EXPO 2015, consisted of a population assessment aimed at evaluating the prevalence of specific health metrics in persons outside of a conventional research setting (n=1924), with a special focus on muscle mass and strength. The Taiwanese survey used the first-wave sampling from the I-Lan Longitudinal Aging Study (ILAS) collected from August 2011 to August 2013 (n=1839). ILAS was designed to explore the interrelationship between sarcopenia and frailty in community-dwelling older people in Taiwan. In both studies, muscle mass was estimated by measuring the calf circumference (CC), whereas muscle strength was assessed by handgrip strength testing.

RESULTS: The mean age of the 1924 Italian participants was 62.5years (standard deviation 8.3, range from 50 to 98years), of whom 1031 (53.6%) were women. Similarly, the mean age of the Taiwanese sample was 63.9years (standard deviation 9.3, range from 50 to 92years), with 966 (52.5%) women. CC declined with age in both genders and was significantly greater among Italian participants compared with Taiwanese people in all age groups. A similar effect of age was observed for muscle strength. As for CC, muscle strength was significantly greater among Italian persons relative to Taiwanese participants.

CONCLUSION: Muscle mass and strength declined with age in both ethnic groups. Caucasians showed greater muscle mass and performed better than their Asian counterparts. However, the age at which declines began to appear and the rate of decline during aging were comparable between the two populations.