Lifestyle factors associated with muscle mass among obese population:The Healthy Twin study, Korea

Abstract

Introduction Sarcopenia was defined as the loss of skeletal muscle mass due to aging. Sarcopenic obesity, characterized by the loss of muscle mass and the increase of fat tissue, showed a synergistic effect on chronic diseases. Lifestyle factors were regarded as risks for sarcopenic obesity

therefore, we tried to investigate the lifestyle factors associated with muscle mass among obese population in the Healthy Twin study, Korea.

Method We gathered informations, including DEXA from the healthy twin study of Korea and included those with a body mass index (BMI) ≥25kg/m2. Multiple linear regression between muscle mass and lifestyle factors such as age, smoking, alcohol consumption, physical activity, BMI, proportion of protein intake, and proportion of carbohydrate intake were used, and co-twin control analysis was analyzed among monozygotic (MZ) twins. The muscle mass indices were weight-adjusted appendicular skeletal mass (ASM), height-adjusted ASM, and skeletal muscle mass index (SMMI) acquired from DEXA.

Results In total, 919 participants were included, and 74 pairs of MZ twin data were used for co-twin control analysis. Increased physical activity and the proportion of protein intake were positively associated with muscle mass in men. BMI was positively associated with height-adjusted ASM and negatively with both weight-adjusted ASM and SMMI. In co-twin control analysis, physical activity and the proportion of carbohydrate intake were positively related with muscle mass. The proportion of protein intake was associated with muscle mass with marginal significance.

Discussion We suggest that physical activity and both carbohydrate and protein intake could positively influence muscle mass among the obese population. To prevent sarcopenic obesity, an increase of physical activity and proportion of carbohydrate and protein intake should be encouraged.