A blunted nocturnal blood pressure decline is associated with all-cause and cardiovascular mortality

It has been suggested that a blunted nocturnal blood pressure (BP) decline is associated with a poor prognosis. Nevertheless, it remains unclear if an abnormal dipping is deleterious per se or it merely reflects an elevated BP during sleep. We aimed to assess the prognostic value of nocturnal BP decline, with or without concomitant elevated nocturnal BP.

Vital status and cause of death were obtained from death certificates in 59 124 patients, enrolled in the Spanish ABPM Registry between 2004 and 2014 (median follow-up: 10 years). The association between night-to-day ratio (NDR) and dipping patterns (extreme dippers, dippers, reduced dippers, and risers) with all-cause and cardiovascular mortality were evaluated by Cox-proportional models adjusted for clinical confounders and 24 h blood pressure.

NDR was associated with all-cause mortality [hazard ratio for 1SD change: 1.15; 95% confidence interval (CI) 1.13-1.17]. Reduced dippers (1.13; 1.06-1.20) and risers (1.41; 1.32-1.51) were associated with an increased risk of all-cause death, whereas extreme dippers (0.90; 0.79-1.02) were not. Elevated NDR (≥0.9) in the absence of elevated night SBP (<120 mmHg) was associated with an increased risk of death (1.13; 1.04-1.22), as well as elevated night SBP but normal NDR (1.38; 1.26-1.50), and the combination of both abnormalities (1.56; 1.46-1.66). Similar results were obtained for cardiovascular mortality.

Abnormalities in the circadian pattern are associated with an increased risk of all-cause and cardiovascular mortality. This is maintained even in the absence of nocturnal BP elevation.