Anthropometric measurements as markers of elevated blood pressure among Portuguese children and adolescents

Purpose This cross-sectional study investigated the association between anthropometric measurements and age-related blood pressure (BP) in a large cohort of Portuguese children and adolescents. Methods We included 2972 individuals aged 2-18 years, drawn from previous study databases. Participants were categorized into four groups: preschoolers (2-5 years), primary schoolers (6-10 years), middle schoolers (11-14 years) and high schoolers (15-18 years). Elevated BP was defined as systolic and/or diastolic BP > 90th percentile for age and sex. Age-adjusted partial correlations with BP were computed for body mass, body mass index (BMI), waist circumference, and waist-to-height ratio. Receiver operating characteristic (ROC) analysis was used to determine the predictive capacity each of these measurements for identifying individuals with elevated BP. Results Elevated BP was observed in 32% of the sample. Partial correlations ranged from small to moderate (0.2-0.5, p < 0.05). As indicated by ROC curves, BMI emerged as the most accurate predictor of elevated BP (AUC = 0.584-0.724, p < 0.05). BMI cut-off values were established to balance sensitivity (SE) and specificity (SP): Preschoolers-girls: BMI > 16.42 kg/m(2) (SE = 71.28%, SP = 46.52%); boys: BMI > 18.25 kg/m(2) (SE = 30.2%, SP = 85.30%); Primary-schoolers-girls: BMI > 20.67 kg/m(2) (SE = 39.02%, SP = 91.45%); boys: BMI > 17.61 kg/m(2) (SE = 67.50%, SP = 71.43%); Middle-schoolers-girls: BMI > 24.01 kg/m(2) (SE = 36.26%, SP = 88.30); boys: BMI > 20.04 kg/m(2) (SE = 65.17%, SP = 64.62%); High-schoolers-girls: BMI > 22.77 kg/m(2) (SE = 56.52%, SP = 69.62); boys: BMI > 21.09 kg/m(2) (SE = 71.20%, SP = 63.20%). Conclusion BMI was the strongest correlate of elevated BP in Portuguese children and adolescents, proving useful for early hypertension risk identification.