Cardiometabolic Risk in Children and Adolescents: The Paradox between Body Mass Index and Cardiorespiratory Fitness

BACKGROUNDCardiometabolic risk has been shown to be inversely associated with cardiorespiratory fitness (CRF) and positively associated with body mass index (BMI). OBJECTIVEOur objective was to analyze the association of cardiometabolic risk factors with combined BMI and CRF in schoolchildren from a city in southern Brazil. METHODSCross-sectional study with a sample of 1252 schoolchildren aged seven to 17 years. Total cholesterol (TC), HDL-c, LDL-c, triglycerides (TG), systolic (SBP) and diastolic blood pressure (DBP) were evaluated. CRF and BMI were grouped into one variable and the schoolchildren were classified as eutrophic/fit, eutrophic/unfit, overweight-obese/fit, and overweight-obese/unfit. Crude and adjusted analyzes were performed using Poisson Regression and an alpha of 0.05 was adopted. RESULTSOverweight-obese and fit schoolchildren showed a prevalence ratio (PR) of 1.50 (1.04 - 2.16) for altered TG, 3.05 (2.05 - 4.54) for elevated SBP, and 2.70 (1.87 - 3.88) for elevated DBP. Overweight-obese and unfit schoolchildren showed a PR for high TC of 1.24 (1.11 - 1.39) and 1.51(1.11 - 2.04) for low HDL levels. In addition, they had a risk of 2.07 (1.60 - 2.69) for altered TG, 3.36 (2.31 - 4.60) for elevated SBP and 2.42 (1.76 - 3.32) for altered DBP. CONCLUSIONBMI played a central role in the association with risk and CRF was shown to attenuate the association between risk factors and obesity. Overweight-obese children and adolescents had a higher cardiometabolic risk, but the effect size was larger among the unfit.