Ambulatory Blood Pressure Thresholds and Left Ventricular Hypertrophy in Children Aged 6–12 Years: A Pediatric Nephrology Research Consortium Study

OBJECTIVE: To evaluate the diagnostic performance of ambulatory blood pressure monitoring (ABPM) thresholds for predicting left ventricular hypertrophy (LVH) in children aged 6-12 years. STUDY DESIGN: A retrospective, multicenter study was conducted across 11 Pediatric Nephrology Research Consortium (PNRC) sites and included children aged 6-12 years who underwent ABPM and two-dimensional (2D) echocardiography for diagnostic assessment of elevated blood pressure (BP). Diagnostic accuracy of fixed ABPM thresholds and the current 95th percentile for sex and height were assessed using area under the receiver operating characteristic (AUROC), sensitivity, specificity, and Youden index. Multivariable logistic regression models, adjusted for age, sex, and body mass index (BMI) z-score, were used to evaluate associations of ABPM thresholds with LVH. RESULTS: Among 279 children, hypertension was present in 51%, and LVH in approximately 20%. Across all systolic and diastolic ABPM thresholds tested, AUROC values ranged from 0.5 to 0.6, indicating poor discriminatory performance, including analyses restricted to children without chronic kidney disease or obesity. Although daytime and 24-hour BP thresholds were not significantly associated with LVH, nighttime systolic BP ≥110 mmHg and nighttime diastolic BP ≥70 mmHg both increased odds of LVH approximately twofold (OR for nighttime SBP 1.93; 95% CI, 1.07-3.50; p=0.03; and OR for nighttime DBP 2.27; 95% CI, 1.08-4.76; p=0.03). CONCLUSIONS: In this multicenter cohort of US children aged 6-12 years, percentile-based and fixed ABPM thresholds demonstrated limited ability to discriminate LVH. Nighttime systolic and diastolic BP showed the strongest associations with LVH, underscoring the importance of nocturnal BP assessment.