Relationship of ambulatory blood pressure and body mass index to left ventricular mass index in pediatric patients with casual hypertension.

Both obesity and hypertension are associated with left ventricular hypertrophy (LVH) in children. Our objective was to compare the prevalence of LVH in obese and nonobese subjects with casual hypertension who underwent ambulatory blood pressure monitoring (ABPM). Untreated children (aged 6-20 years) underwent 24-hour ABPM, and left ventricular mass index (LVMI) was measured. Subjects were classified into three groups: white coat hypertension (WCH), prehypertension (pre-HT), and hypertension (HT). The prevalence of LVH was compared between obese and nonobese subjects among the groups. Of 69 children who underwent ABPM, thirty-two patients (46%) had WCH, 13 (19%) had pre-HT, and 24 (35%) had HT. Mean age, BMI, and LVMI were similar in the groups (P = not significant [NS]). In all, 22 patients (32%) had LVH, with no difference among WCH versus pre-HT versus HT (37.5% vs. 46% vs. 16.7%, P = NS). Twenty-seven subjects (39%) were obese. The ratio of LVH in obese to nonobese was 55.5% to 16.6% (P = .001). In both pre-HT and WCH, patients with LVH had a significantly higher BMI z score (P = .02 and P = .01, respectively). LVMI correlated strongly with BMI z score (P = .0001) but not with any blood pressure parameter. Almost half of children with casual HT have WCH. LVH is prevalent in a third of children with HT, pre-HT, and WCH. In both pre-HT and WCH, patients with LVH were more likely to be obese. More than half of all the obese subjects had LVH. Obese children in all three groups may be at a greater risk for end organ damage.