Sarcopenia-related features and factors associated with low muscle mass, weak muscle strength, and reduced function in Chinese rural residents: a cross-sectional study.

Muscle strength and function declined more than the concomitant loss of muscle mass. Measures of muscle strength and function are an effective way to assess functional ability and physical health in older people. A healthy lifestyle such as physical exercise, good nutrition, and higher BMI can benefit older people.

INTRODUCTION: The study investigated the characteristics of aging-related differences in appendicular lean mass (ALM/Ht2 ), handgrip strength (HGS), usual gait speed (UGS), repeated chair stands (RCS), Timed Up and Go (TUG) test, and their associated factors in 6703 rural residents.

METHODS: We assessed their anthropometry, body composition, muscle strength and function, bone mineral density, blood pressure, and blood biochemical indices via clinical examination or laboratory tests and investigated demographic characteristics, lifestyle, medical history, physical activity, and dietary intake via questionnaire. Stepwise logistic regression was used to determine the associated factors of low muscle mass, weak muscle strength, reduced physical performance, and sarcopenia.

RESULTS: The mean values of muscle strength and function decreased more rapidly with age than the mean values of muscle mass, especially in females. The prevalence of low ALM/Ht2 , weak HGS, slow UGS, long RCS, long TUG, and sarcopenia increased (P < 0.01). Higher body mass index (BMI) and daytime sleep were associated with high ALM/Ht2 . Comorbidity factors such as hypertension, bone mineral density loss, central adiposity, metabolic syndrome, and tumors were associated with the risk of weak muscle strength and reduced physical performance, while physical activity and better nutrition were associated with better muscle strength and physical performance.

CONCLUSIONS: At the higher decades of life, the decline of muscle strength and function is greater than the loss in muscle mass. Measures of muscle strength and function are an effective way to assess functional ability and physical health in older people. Maintaining a healthy lifestyle by means such as physical exercise, good nutrition, and higher BMI throughout the course of life may be benefit older people by improving their muscle mass, strength, and function.