A Reverse Dipping Pattern Predicts Cardiovascular Mortality In a Clinical Cohort

Abstract

An abnormal dipping pattern in ambulatory blood pressure monitoring (ABPM) is a cardiovascular (CV) risk factor. However, its impact on CV mortality has not been investigated sufficiently in clinical practice to be considered a standard parameter. We assessed the association between abnormal dipping patterns and increased CV mortality in a tertiary hospital in Korea. Our retrospective cohort study included 401 patients who underwent ABPM between 1994 and 1996 in Hanyang University Hospital, Seoul, Korea. The patients were classified as risers (<0% drop in systolic BP; n=107), and others included dippers and non-dippers (≥0% drop, n=294). The follow-up period was 120 months. The frequency of CV mortality was 14.0% in risers and 5.8% in others. A Cox regression analysis found a significant association between dipping pattern and CV mortality, after adjusting for age, gender, body mass index, hypertension, diabetes mellitus, smoking and hypercholesterolemia. Risers were at greater risk of CV death than others (RR, 3.02, P=0.022), but there was no difference in event rates between dippers and non-dippers. The reverse dipping pattern may be more frequent in clinical settings than in the population at large, and it is strongly associated with increased risk of CV mortality in Korea.