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

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. 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. 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/m2 (SE = 71.28%, SP = 46.52%); boys: BMI > 18.25 kg/m2 (SE = 30.2%, SP = 85.30%); Primary-schoolers—girls: BMI > 20.67 kg/m2 (SE = 39.02%, SP = 91.45%); boys: BMI > 17.61 kg/m2 (SE = 67.50%, SP = 71.43%); Middle-schoolers—girls: BMI > 24.01 kg/m2 (SE = 36.26%, SP = 88.30); boys: BMI > 20.04 kg/m2 (SE = 65.17%, SP = 64.62%); High-schoolers—girls: BMI > 22.77 kg/m2 (SE = 56.52%, SP = 69.62); boys: BMI > 21.09 kg/m2 (SE = 71.20%, SP = 63.20%). BMI was the strongest correlate of elevated BP in Portuguese children and adolescents, proving useful for early hypertension risk identification.