Reference values for the tri-ponderal mass index and its association with cardiovascular risk factors in Brazilian adolescents aged 12 to 17 years

Abstract

ObjectivesThe aims of this study was to determine the cutoff values for tri-ponderal mass index (TMI) and investigate the association between overweight/obesity as classified by TMI and cardiometabolic risk factors in Brazilian adolescents aged 12 to 17 y. MethodsThis was a cross-sectional study comprising 37 815 adolescents (40 % boys; 12–17 y) enrolled in the Study of Cardiovascular Risks in Adolescents. TMI was calculated as weight divided by cubed height (kg/m3). Overweight (TMI-for-age ≥85th percentile to <95th percentile) and obesity (TMI-for-age ≥95th percentile) were determined for both sexes. Poisson regression model analyses were used to test associations. ResultsTMI was stable across the age span (12–17 y) in both sexes. Boys and girls classified by TMI as obese had higher prevalence ratios (PR) for hypertension (PR, 4.98; 95% confidence interval [CI], 3.26–7.61 for boys; PR, 6.88; 95% CI, 3.70–12.78 for girls), insulin resistance (PR, 19.72; 95% CI, 13.56–28.69 for boys; PR, 10.04; 95% CI, 7.47–13.50 for girls), hypercholesterolemia (PR,5.05; 95% CI, 3.68–6.94 for boys; PR, 1.44; 95% CI, 1.00–2.11 for girls), and hypertriacylglycerolemia (PR,7.36; 95% CI, 5.16–10.50 for boys; PR, 3.37; 95% CI, 2.52–4.51 for girls) when compared with normal weight counterparts. ConclusionsObesity, as classified by TMI, was strongly associated with several cardiovascular risk factors. Our data showed that TMI was stable across the age span. Therefore, a fixed cutoff value to determine weight status in Brazilian adolescents seems appropriate.