Higher Appendicular Skeletal Muscle Mass Protects Metabolically Healthy Obese Boys but Not Girls from Cardiometabolic Abnormality

Factors related to metabolically healthy obesity (MHO) are not well characterized in adolescents. The study's aim was to investigate the impact of skeletal muscle mass (SMM) on MHO in adolescents. A secondary analysis was performed using the data of 221 Korean overweight and obese adolescents aged 12⁻18 years from the Korean National Health and Nutrition Examination Survey. Appendicular skeletal muscle (ASM) mass and total body fat mass were measured by dual-energy X-ray absorptiometry. Being metabolically unhealthy was defined using three definitions: Having ≥1, ≥2, or ≥3 cardiometabolic risk factors (CRFs; waist circumference, blood pressure, glucose, triglycerides, and HDL-cholesterol). Multiple logistic regression analyses adjusted for age and lifestyle factors were performed to assess the association between ASM and MHO. In boys, the risk for having either ≥2 CRFs or ≥3 CRFs was significantly lower with higher weight-adjusted ASM and ratio of ASM to fat mass after controlling for covariates, but this association was not significant with CRFs ≥ 1. In girls, all adjusted odds ratios were not significant. Findings indicate that SMM is a potentially protective factor against cardiometabolic abnormality in adolescents with MHO, showing gender difference. This heightens the importance of SMM in the management of obesity, especially in boys.