Association between obesity and the severity of ambulatory hypertension in children and adolescents

The goal of our study was to analyze the association between obesity and the severity of ambulatory hypertension in obese children. A total of 109 patients with primary obesity ages 7 to 18 years (mean +/- SD age 14.1 +/- 3.1) were enrolled. Patients were divided into three groups according to body mass index (BMI) Z-scores: group 1 (n = 27): BMI >1.65 and < 3.28 standard deviation scores (SDS); group 2 (n = 55): BMI >3.29 and <4.91 SDS; group 3 (n = 27): BMI >4.92 SDS. Definition and staging of ambulatory hypertension was based on blood pressure (BP) levels and BP load, obtained from ambulatory BP monitoring (ABPM). Only 24% had ambulatory normotension, 25% had ambulatory prehypertension, 3% had hypertension, and 48% had severe ambulatory hypertension. The severity of hypertension increased significantly with the degree of obesity (P = .0027). Daytime systolic, diastolic, and mean arterial BPs increased significantly with increased BMI, whereas the nighttime pressure remained elevated regardless of the degree of obesity. Isolated nighttime hypertension was observed in 25% of patients and 38% were classified as nondippers. Almost 50% of children with obesity and hypertension detected on ABPM suffer from severe ambulatory hypertension. BMI is associated with the severity of ambulatory hypertension and the increase of daytime BP. J Am Soc Hypertens 2012;6(5):356-363. (C) 2012 American Society of Hypertension. All rights reserved.