RISK OF BLOOD PRESSURE MISCLASSIFICATION IN TALL BOYS ACROSS DEVELOPMENTAL PERIODS

Abstract

Objective: Screening for hypertension in childhood and adolescence represents a key strategy for prevention of early vascular aging and consequent target organ damage later in life. Regarding the effect of anthropometric characteristics, emphasis is presently placed on elevated blood pressure (BP) in overweight/obese children. The effect of height on BP is often underestimated, despite its incorporation into normative BP data. The risk of misclassification of hypertensive vs. normotensive individuals seems to be particularly expressed in boys. Therefore, we aimed to study the relationship between height, measures of adiposity, and BP in healthy normal-weight boys in distinct developmental age periods. Design and method: 250 healthy normal-weight boys in age groups of 7–10 (n = 73), 11–14 (n = 85), and 15–19 years (n = 92) were examined under standard conditions. Weight, height, and waist circumference were measured, and two indices of adiposity were calculated: body mass index (BMI; kg.m-2) and body roundness index (BRI; -). Right brachial BP was measured oscillometrically, and mean BP was used for statistical analyses. Results: In multiple linear regression analysis, out of the three anthropometric parameters (height, BMI, and BRI), BP in adolescents aged 15–19 years was best predicted by height (regression coefficient 25.198 mmHg/m, p = 0.013), compared to BMI and BRI (p = 0.102, p = 0.921, respectively). Linear regression analyses showed significant effects of height and BMI, but not BRI, on mean BP in adolescents aged 15–19 years (height: 29.039 mmHg/m, p = 0.004; BMI: 0.847 mmHg/kg.m2, p = 0.014; BRI: p = 0.252). No significant linear relationship between the anthropometric parameters (height, BMI, and BRI) and mean BP was detected in boys aged 7–10 and 11–14 years. Conclusions: The effect of height on BP was most expressed in adolescent boys aged 15–19 years. BP should be evaluated with caution in this paediatric population due to increased risk of misclassification of normotensive individuals as hypertensive. These findings may be related to both physiological adaptation to greater height and a previously described “spurious” peripheral hypertension resulting from specific alteration of peripheral wave reflection in young tall boys with greater elasticity of the arterial wall.