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Objective: A blunted nocturnal BP decline is associated with an increased cardiovascular risk. Nevertheless, patients with a reduced BP dip usually have higher levels of nighttime BP, being both parameters… Click to show full abstract
Objective: A blunted nocturnal BP decline is associated with an increased cardiovascular risk. Nevertheless, patients with a reduced BP dip usually have higher levels of nighttime BP, being both parameters clearly related. The aim of the study was to assess the prognostic value of nocturnal BP decline, independently of the presence or not of nocturnal BP elevation. Design and method: Vital status and death due to cardiovascular causes were obtained from death certificates in 59110 adults, mostly hypertensives, enrolled in the Spanish ABPM Registry between 2004 and 2014, and having a valid 24-h ABPM at entry. On the basis of BP data, patients were classified in 4 groups: Normal (<120 mmHg) night systolic BP (SBP) and normal (<0.9) systolic night-to-day ratio (NDR). Normal night SBP with elevated (> = 0.9) NDR. Elevated (> = 120 mmHg) SBP with normal NDR and both elevated SBP and NDR. Association between NDR, dipping status and groups combining night SBP and NDR with total and cardiovascular mortality were assessed by Cox models, adjusted for clinical confounders. Results: The total number of deaths were 2866 (978 of cardiovascular causes) during a median follow-up of 5 years. NDR predicted total mortality (HR for 1 SD change: 1.19; 95%CI: 1.15–1.23). Both patients with reduced dipping (HR: 1.28; 1.17–1.41) and risers (HR: 1.59; 1.42–1.77) had increased risk of total mortality, whereas extreme dippers (NDR < 0.8) did not. With respect to patients with both normal night SBP and NDR, those with elevated NDR in the absence of elevated night SBP had increased risk of death (HR: 1.36; 1.19–1.55), as well as those with elevated night SBP and normal NDR (HR; 1.40; 1.21–1.62). Those combining both abnormalities had the highest risk (HR: 1.78; 1.60–1.98). Similar results were obtained for cardiovascular mortality. Conclusions: Abnormalities in the circadian dipping pattern are responsible for an increased risk of mortality, both total and cardiovascular. Increased mortality rates are observed in patients with a reduced nocturnal dip and, even more intensively, in those with a riser pattern. This abnormal dipping increases the risk of mortality even in the absence of BP elevation.