Physical activity interacts with adiposity in determining cardiometabolic risk in adolescents.

Background: Moderate-to-vigorous physical activity (MVPA) has been negatively associated with cardiometabolic risk. We sought to determine if MVPA interacts with body-mass index (BMI) and waist circumference (WC) in determining cardiometabolic risk in adolescents.

Methods: This cross-sectional study included cardiometabolic risk (blood pressure [BP], nonfasting lipids) screening and a 7-day recall physical activity questionnaire in 4,104 adolescents (51% male; mean age: 14.6 ± 0.5 years old). WC- and BMI- percentiles were used to define anthropometric categories (including obese adolescents: 90th WC, 85th BMI).

Results: Obesity in adolescents was associated with lower levels of high-density lipoprotein (HDL cholesterol (Estimate [EST]: -0.28(0.07) mmol/L, p < .001) and higher non-HDL cholesterol (EST: +0.38(0.14) mmol/L, p = .008). Each additional day with 20 min of MVPA was associated with lower non-HDL cholesterol (EST: -0.014(0.005) mmol/L/days/week, p = .003), independent of anthropometric category. Each additional day with 20 min of MVPA was associated with an increased odds ratio (OR) for higher BP category in obese adolescents (OR: 1.055, 95% CI: 1.028-1.084, p < .001) and a lower odds ratio for higher BP category in presumably-muscular adolescents (OR: 0.968, 95% CI: 0.934-0.989, p = .005).

Conclusions: An increase in MVPA was associated with an increased likelihood for higher BP category in obese adolescents. The dose-response relationship between physical activity and cardiometabolic risk needs to be evaluated in adolescents of varying anthropometry categories.