Can office blood pressure readings predict masked hypertension?

Studies in children with chronic kidney disease indicate a high prevalence of masked hypertension detected by ambulatory blood pressure monitoring (ABPM). However, it is not well known if the frequency of masked hypertension is related to the level of normal casual blood pressure (BP). We hypothesized that lower levels of normal casual BP are associated with a lower prevalence of masked hypertension. Data from the chronic kidney disease (CKiD) cohort were analyzed cross-sectionally across multiple visits. The majority of children with normal casual BP also had normal wake and sleep ABP (60 %), even at the highest percentiles of casual BP. The frequency of masked hypertension was lower in children with casual BP a parts per thousand currency sign25th percentile versus those with casual BP in 26-50th percentile and casual BP in 51-90th percentile during both wake and sleep periods. In children with the lowest normal casual BP levels (a parts per thousand currency sign25th percentile), the frequency of abnormal mean wake or sleep ABP was 2-7 %, and of abnormal BP load was 6-16 %. These data suggest that masked hypertension is unlikely if the casual BP is found to be in the low normal range.