Body mass index and waist circumference as predictors of blood pressure in children and adolescents with obesity

Objective To identify the relationship of body mass index (BMI) and waist circumference (WC) values for systolic (SBP) and diastolic blood pressure (DBP) in children and adolescents with obesity. Methods We studied 65 children and adolescents with obesity (BMI > percentile 95). Anthropometric and laboratory assessment was conducted; blood pressure measurement in triplicate adjusted for age and height. Results 40 boys and 25 girls with a mean age of 10.4 ± 3.0 years. Blood pressure was lower than 90 percentile on 93.8%, only two cases (3.1%) between 90 and 95 percentile and two above the 95 percentile. WC showed a better correlation with SBP than BMI (r = 0.38, p = 0.001 versus r = 0.27, p = 0.01), whereas for DBP, the correlation was similar for WC and BMI (r = 0.38, p = 0,001). Multivariate models for SBP and DBP showed greater influence of WC than BMI. Discussion The magnitude of the observed correlation seems to confirm a better relation of WC with blood pressure. BMI is not able to distinguish between subjects with excess adipose tissue or those with increases in muscle mass. Parameters considering abdominal adiposity have better relationship with cardiovascular risk factors.