White coat hypertension in children with elevated casual blood pressure

Abstract

Objective: We reviewed our experience using ambulatory blood pressure monitoring (ABPM) in children referred to a hypertension clinic to determine the frequency of pediatric white coat hypertension (WCH). Study design: WCH was defined by 3 different diagnostic criteria: (1) mean 24-hour blood pressure (BP) less than Task Force–defined 95th percentile, (2) mean 24-hour BP less than 95th percentile from pediatric normative ABPM data, and (3) mean 24-hour BP less than ABPM 95th percentile and BP load (percentage of BP readings during 24-hour period exceeding the 95th percentile) less than 25%. Results: Clinic BP values were available in 67 otherwise healthy children who underwent ABPM; 51 had confirmed clinic hypertension by Task Force criteria. WCH frequency in these 51 patients with the stated criteria was 53%, 45%, and 22%, respectively. Elevated BP load was found in 52% (12/23) of patients with normal mean BP. Conclusion: These results suggest that many children referred for casual BP elevation have WCH even by strict diagnostic criteria. ABPM may help differentiate WCH from persistent hypertension, thereby avoiding unnecessary diagnostic evaluation and identifying children most likely to benefit from early intervention. (J Pediatr 2000;137:493-7)