Association between cardiorespiratory fitness and cardiometabolic risk factors in Brazilian children and adolescents: the mediating role of obesity parameters

Background: There is a lack of clarity as to which obesity parameters may be more important in the association between cardiorespiratory fitness (CRF) and cardiometabolic risk factors (CMRF). Aim: To verify the mediating role of different obesity parameters on the association between CRF and CMRF in normal weight and overweight/obese children and adolescents. Methods: This cross-sectional study comprised 999 children and adolescents (534 boys) aged 7–14 years from the south of Brazil. Body mass index (BMI), waist circumference (WC), waist-to-height ratio (WHtR) and percentage of body fat were assessed. Participants were classified as normal weight, overweight and obese according to BMI. CRF was evaluated by the 6-minute run/walk test. . A continuous CMRF score was calculated by summing the Z-scores of the following variables: systolic and diastolic blood pressure, glucose, total cholesterol, high-density lipoprotein cholesterol and triglycerides. Data analysis was performed using partial correlation and linear regression models. Results: BMI, WC, WHtR and percentage of body fat mediated the relationship between CRF and CMRF in overweight/obese boys and girls but not those of normal weight. Additionally, the percentage of the influence of each obesity parameter was 20% for BMI and WC, 16% for percentage of body fat and 18% for WHtR in girls. For boys, the mediation effect was 25% for BMI, 26% for WC, 28% for percentage of body fat and 25% for WHtR. Conclusion: Adiposity plays a central role in CMRF; therefore, maintaining an adequate weight status should be an important objective of health-promoting programmes in early age. Abbreviations: CMRF, cardiometabolic risk factors; CRF, cardiorespiratory fitness; BMI. body mass index; HDL-c, high-density lipoprotein cholesterol, PROCESS PROESP-Br, Projeto Esporte Brasil; SPSS, Package for Social Sciences; TC, total cholesterol; TG, triglycerides; WC, waist circumference; WHtR, waist-to-height ratio; %BF, percentage of body fat.