Differential Association Between Sarcopenia and Metabolic Phenotype in Korean Young and Older Adults with and without Obesity

Objective: To determine whether sarcopenia was associated with metabolic phenotype in subjects with and without obesity. Methods: A total of 6,021 participants (2,592 men, 3,429 women) aged 30 to 93 years were assessed using data from the 2009 Korea National Health and Nutrition Examination Survey. Sarcopenia was defined as appendicular skeletal muscle mass divided by weight (%) that is <1 SD below the sexspecific mean for young adults. Metabolically unhealthy was defined as >= 2 components of metabolic syndrome or the presence of hypertension, diabetes, or cardiovascular disease. Obesity was defined as body mass index >= 25.0 kg/m(2). Results: Sarcopenia was associated with a metabolically unhealthy phenotype in nonobese men independent of age, smoking, regular physical activity, daily energy intake, total body fat, fasting insulin, nonHDL cholesterol, white blood cell count, ferritin level, and 25(OH) vitamin D level (OR per 1 SD increment (95% CI) 1.88 (1.28-2.75), P < 0.01), but this association was confounded by and not independent of total body fat in nonobese women. Sarcopenia was not associated with a metabolically unhealthy phenotype in subjects with obesity. Conclusions: Sarcopenia was independently associated with a metabolically unhealthy phenotype in nonobese men, but this association was not evident in nonobese women or subjects with obesity.