Differences in Obesity Diagnostic Methods and Hypertension Phenotypes in Adolescents from the BRISA Cohort - a Cross-Sectional Analysis

• Grant number: 25/11537-2
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: September 01, 2025
• End date: August 31, 2026
• Field of knowledge: Health Sciences - Medicine - Maternal and Child Health
• Principal Investigator: Ivan Coelho Machado
• Grantee: Laura Silva de Carvalho Quintino
• Host Institution: Faculdade de Medicina de Ribeirão Preto (FMRP). Universidade de São Paulo (USP). Ribeirão Preto , SP, Brazil

Abstract

Childhood and adolescent hypertension and obesity are chronic conditions with rising prevalence and significant public health impact. Their coexistence substantially increases the risk of cardiovascular complications from an early age. Obesity in adolescents can be diagnosed using different methods, including body mass index (BMI), waist circumference (WC), and body fat percentage via dual-energy X-ray absorptiometry (DXA), each with specific advantages and limitations. Ambulatory blood pressure monitoring (ABPM) has emerged as a valuable tool for classifying hypertensive phenotypes, such as masked and white coat hypertension, with higher accuracy compared to office blood pressure readings.This study aims to compare the prevalence of obesity across different hypertension phenotypes defined by ABPM in adolescents from the BRISA cohort in Ribeirão Preto. The secondary objective is to estimate the prevalence of hypertension among obese and non-obese adolescents, using different diagnostic criteria (BMI, WC, and body fat percentage). This is a cross-sectional, observational study using data from the second follow-up (ages 11-13) of the BRISA cohort, which includes individuals followed since gestation or birth.The estimated sample comprises 1006 adolescents. Participants with inconclusive ABPM reports, renal diseases, secondary causes of hypertension, or antihypertensive use will be excluded. Office BP was measured using a validated oscillometric device (OMRON HBP-1100), and ABPM was performed using the TM-2430 monitor (DMS® Brazil). Hypertension phenotypes will be defined based on the 2022 American Heart Association guidelines: normal BP, white coat hypertension, masked hypertension, and ambulatory hypertension.Anthropometric measurements (weight, height, WC) were taken by trained staff. BMI was converted to Z-scores using WHO growth curves. Body fat was measured by DXA and classified according to McCarthy et al., and WC was considered elevated when above the 90th percentile. Sociodemographic and family history variables will also be analyzed.Statistical analysis will be conducted in Python, including descriptive statistics and chi-square tests for associations between obesity and hypertension phenotypes, with a 5% significance level.Although many studies address arterial hypertension, research involving children and adolescents is more challenging and less frequent. Most hypertension research focuses on adults, leaving a gap in pediatric data, particularly regarding long-term effects. The association between obesity and hypertension is well documented; however, its expression across populations and methodologies remains incompletely understood. This study seeks to bridge that gap, providing valuable insights for early screening and cardiovascular prevention strategies in adolescents. (AU)