Abstract P187: Obesity predicts left ventricular mass in youth undergoing ambulatory blood pressure monitoring

Abstract

Background: Left ventricular hypertrophy (LVH) is a risk factor for cardiovascular disease in adults. In youth, elevated blood pressure (BP) is associated with LVH, but independent effects of adiposity and hypertension on LVH are not well defined. The purpose of our study was to investigate relationships among LVH, LV mass, BMI, and other clinical parameters in pediatric patients referred for elevated BP. We hypothesized both BP and BMI to be associated with LV mass. Methods: We conducted an IRB-approved retrospective chart review of all patients ages 6-18 years who underwent 24-hour ambulatory BP monitoring via the pediatric nephrology clinic at Kentucky Children’s Hospital from August 2012-December 2023 (excluding those with secondary HTN). Obesity was defined by BMI and weight-for-length percentiles according to CDC guidelines. LV mass was assessed by standard echocardiography. We compared LVMI and BP measures among groups stratified by obesity stage. Associations among BP, obesity, and LVMI were determined using descriptive statistics, correlational analyses, and multivariable logistic modeling using a backwards elimination variables selection criteria with α=0.05. Results: Of the 520 patients, 66% (n=342) were male, 76% (n=395) were obese, and 46% (n=238) had LVH. LVMI was strongly correlated with 24-hr systolic BP, however there was no difference in mean LVMI across BP severity category. In contrast, there was a near stepwise increase in LVMI across obesity stage with the strongest effect in girls – Normal: 29.7 ± 5.3 (girls) v. 34.8 ± 11.4 (boys) g/m 2.7 ; OB-1: 36.5 ± 6.6 (girls) v. 43.2 ± 10.3 (boys) g/m 2.7 ; OB-2: 41 ± 11.6 (girls) v. 44.2 ± 9.2 (boys) g/m 2.7 ; OB 3: 48 ± 11.6 (girls) v. 43.5 ± 9.4 (boys) g/m 2.7 . LVMI was positively correlated with TSH, creatinine, uric acid, cystatin, and inversely correlated with HDL. Multivariable logistic modeling revealed obesity stage and HDL cholesterol, but not BP or laboratory variables, as significant independent predictors of LVH. Conclusions: We report a high incidence of LVH in youth with obesity and demonstrate a strong association between obesity and LVMI. Our data, in agreement with previous studies, indicate that adiposity is a significant determinant of left ventricular mass, and suggest the need for cardiac screening of youth with obesity even in the absence of elevated blood pressure.