Association between physical fitness and cardiometabolic risk of children and adolescents in Korea

Background: This study aimed to investigate the association between physical fitness and cardiometabolic health of Korean children and adolescents. Methods: In total, 168 participants (89 boys and 79 girls) aged 10-16 years were recruited for the Intervention for Childhood and Adolescent Obesity via Activity and Nutrition Study in 2016. The subjects were categorized into two groups using the definition of metabolic syndrome by the International Diabetes Federation: metabolically unhealthy (with at least two of the five criteria) and healthy groups (with less than one criterion). Correlation analysis of the participants' general characteristics was performed. Odds ratios (ORs) of physical fitness for cardiometabolic risk were evaluated via logistic regression. Results: Metabolically unhealthy children showed greater weight, height, and body mass index, higher Children's Depression Inventory score, and longer screen time than did the metabolically healthy children. Metabolically healthy children showed greater upper and lower extremity muscular strength than did the metabolically unhealthy children (P=0.04 and P < 0.001, respectively). In the multiple logistic regression analysis, lower extremity muscle strength was inversely related to the clustered cardiometabolic risk of the children and adolescents with or without adjustment for confounders (OR, 4.32; 95% confidence interval [CI], 1.87-9.97; OR, 7.64; 95% CI, 1.55- 37.74, respectively). Conclusion: Physical fitness, especially lower extremity muscle strength, is significantly inversely associated with individual and clustered cardiometabolic risks in Korean children and adolescents.