REFERENCE VALUES FOR OFFICE BLOOD PRESSURE IN BRAZILIAN ADOLESCENTS

Abstract

Objective: Office blood pressure (BP) references for Brazilian adolescents are missing in the literature. This study aims to investigate the normal range of office BP in a healthy non-overweight Brazilian population of adolescents. Design and method: The Brazilian Study of Cardiovascular Risks in Adolescents (ERICA) is a national school-based study that included adolescents (aged between 12 and 17 years), enrolled in public and private schools, in cities with over 100,000 inhabitants, from all five Brazilian macro-regions. Information about sex, age, type of school (public or private), skin color, smoking, alcohol consumption, and physical activity were obtained from a self-administered questionnaire. Adolescents’ height and body mass index (BMI) were classified in percentiles according to age and gender, and reference curves from the World Health Organization were adopted. Three consecutive office BP measurements were taken with a validated oscillometric device using the appropriate cuff size. Mean values of the last two readings were used for analyses. Polynomial regression models relating BP, age and height were applied. Results: From a total of 73,399 adolescents enrolled, non-overweight individuals represented 74.5% (95%CI 73.3–75.6) of the total sample. Age distribution across the sample varied from 14.1% (95%CI 13.8–14.4) in 17–18 years to 18.0% (95%CI 17.7–18.3) in 15–16 years old. The majority of the non-overweight sample was from public schools 84.2% (95%CI 79.9–87.7) and sedentary 54.8% (95%CI 53.7–55.8). Adolescents’ reporting their skin color as brown (48.8% [95%CI 47.4–50.1]) and white (37.8% [95%CI 36.1–39.5]) were most frequent. Systolic and diastolic 50th, 90th, 95th and 99th BP percentiles by sex, age and height percentiles are provided. Estimated BP increased in both sexes by age and height percentiles. Systolic BP growth patterns were more marked in males when compared to females, along all height percentiles. The same pattern was not observed for diastolic BP. Conclusions: The first Brazilian adolescents’ BP references by sex, age and height based on measurements performed with a validated oscillometric device and following an appropriate methodology for data collection are presented here. The proposed reference values should be used in clinical practice.