Abstract 093: Does Ambulatory Blood Pressure Variability Predicts Target Organ Damage In Youth? The Ship Ahoy Study

Abstract

Altered BP and HR variability are associated with abnormalities of cardiac structure and function in adults. Our aim was to determine if BP and HR variability increase prediction of subclinical cardiac changes in youth after adjustment for mean ambulatory BP (ABP) measures. We measured anthropometrics and performed echocardiography for left ventricular mass index (LVMI), LV systolic strain and LV diastolic function (e’/a’). ABP was measured with an oscillometric device and ABP mean percentiles were calculated per pediatric guidelines to adjust mean ABP for differences in age-, height- and sex. ABP and HR coefficients of variation (CV) were calculated as SD/mean. HR dipping was day mean HR - night mean HR. General linear models were used to determine if ABP and HR CV measures remained significant determinants of cardiac measures in models containing mean ABP levels, age, sex, race/ethnicity, BMIz, HR. Mean age was 15.6 ± 1.7 years (63% white, 59% male) with mean casual BP 122.7/71.6 mmHg ±12.3/10.5, mean daytime ABP 124.2/72.0 ± 11.3/7.7 mmHg. In linear models, DBP day CV, DBP nite CV and HR dip remained significant determinants of LVMI even after adjustment for covariates and ABP percentile (R 2 0.36, p < 0.0001). HR nite CV was a determinant of e’/a’ after adjustments (R 2 0.16, p < 0.0001). No BP or HR variability parameters enter the model for LV systolic strain. When stratified by ABP phenotype, participants with white coat HTN (WCH) had higher 24-hour BP, HR variability and HR dipping compared to other phenotypes. Measures of BP and HR variability which may represent altered autonomic tone, may affect LVM and diastolic function in youth especially those with WCH.