Aerobic fitness, body mass index, and CVD risk factors among adolescents:: the Quebec family study

PURPOSE: The purpose of this study was to examine the association of body mass index (BMI) and aerobic fitness on cardiovascular disease (CVD) risk factors in adolescents. METHODS: The sample included 416 boys and 345 girls 9-18 y of age from the Quebec Family Study. Participants were cross-tabulated into four groups using a median split of age-adjusted physical working capacity (PWC) and body mass index (BMI). Group differences in age-adjusted CVD risk factors (blood pressures, fasting total cholesterol (CHOL), LDL-C, HDL-C, HDL/CHOL, triglycerides, glucose, and a composite risk factor score) were examined by two-way ANOVA. RESULTS: Several CVD risk factors showed significant main effects for PWC, BMI and/or the PWC by BMI interaction. In general, low fit males and females had higher blood lipids and glucose compared to their high fit counterparts within BMI categories although none of the differences reached statistical significance. The high fit/low BMI group showed the best CVD risk factor profile while the low fit/high BMI showed a poorer profile as evidenced by several significant differences between these two groups. Other significant differences occurred for various risk factors between groups. CONCLUSION: Both aerobic fitness and BMI show an independent association with CVD risk factors in adolescents.