Heart failure (HF), hypertension, and abnormal nocturnal blood pressure dipping are highly prevalent in hemodialysis patients. Atrial fibrillation (AF) and HF might be important mediators for the association of abnormal dipping patterns with worse prognosis. Thus, the aim of this study is to investigate the association of dipping with mortality in hemodialysis patients and to assess the influence of AF and HF. In total, 525 hemodialysis patients underwent 24-hour ambulatory blood pressure monitoring. All-cause and cardiovascular mortality served as end points. Patients were categorized according to their systolic dipping pattern (dipper, nondipper, and reverse dipper). Cox regression analysis was performed to determine the association between dipping pattern and study end points with dipping as reference. Subgroup analysis was performed for patients with and without AF or HF. In total, 185 patients with AF or HF and 340 patients without AF or HF were included. During a median follow-up of 37.8 months, 177 patients died; 81 from cardiovascular causes. Nondipping and reverse dipping were significantly associated with all-cause mortality in the whole cohort (nondipper: hazard ratio, 1.95 [1.22-3.14]; P=0.006; reverse dipper: hazard ratio, 2.31 [1.42-3.76]; P<0.001) and in patients without AF or HF (nondipper: hazard ratio, 2.78 [1.16-6.66]; P=0.02; reverse dipper: hazard ratio, 4.48 [1.87-10.71]; P<0.001) but not in patients with AF or HF. For cardiovascular mortality, associations were again significant in patients without AF or HF and in the whole cohort. The observed associations remained significant after adjustment for possible confounders. This study provides well-powered evidence for the association between abnormal dipping patterns and mortality in hemodialysis patients and suggests that HF or AF modifies this association.
Keywords: blood pressure; cohort studies; heart diseases; hypertension; renal dialysis.