Prognostic Effect of the Nocturnal Blood Pressure Fall in Hypertensive Patients

Abstract

A mbulatory blood pressure (BP) monitoring (ABPM) has been increasingly used in clinical management of hypertension. 1,2 It has been consistently demonstrated that ambulatory 24-hour BPs are better cardiovascular risk predictors than office BPs 2,3 and that average nighttime sleep BPs are generally better predictors of adverse cardiovascular outcomes than average daytime awake BP levels on ABPM.2,4,5 There is a normal circadian BP variability, with higher levels during daytime and a 10% to 20% BP fall during sleep.2 In 1988, O'Brien et al 6 reported for the first time that hypertensives with a blunted nocturnal BP fall had a greater prevalence of strokes and named these patients nondippers, in contrast to the normal dippers. Since then, several prospective studies reported on the prognostic value of the nocturnal BP fall both in hypertensives 7-18 and in population-based samples. [19][20][21] However, these results were not consistent possibly because of differences in methodology, study populations, sample sizes, and end points. In particular, many previous studies either did not adjust the Abstract-The prognostic importance of the nocturnal systolic blood pressure (SBP) fall, adjusted for average 24-hour SBP levels, is unclear. The Ambulatory Blood Pressure Collaboration in Patients With Hypertension (ABC-H) examined this issue in a meta-analysis of 17 312 hypertensives from 3 continents. Risks were computed for the systolic night-today ratio and for different dipping patterns (extreme, reduced, and reverse dippers) relative to normal dippers. ABC-H investigators provided multivariate adjusted hazard ratios (HRs), with and without adjustment for 24-hour SBP, for total cardiovascular events (CVEs), coronary events, strokes, cardiovascular mortality, and total mortality. Average 24-hour SBP varied from 131 to 140 mm Hg and systolic night-to-day ratio from 0.88 to 0.93. There were 1769 total CVEs, 916 coronary events, 698 strokes, 450 cardiovascular deaths, and 903 total deaths. After adjustment for 24-hour SBP, the systolic night-to-day ratio predicted all outcomes: from a 1-SD increase, summary HRs were 1.12 to 1.23.Reverse dipping also predicted all end points: HRs were 1.57 to 1.89. Reduced dippers, relative to normal dippers, had a significant 27% higher risk for total CVEs. Risks for extreme dippers were significantly influenced by antihypertensive treatment (P<0.001): untreated patients had increased risk of total CVEs (HR, 1.92), whereas treated patients had borderline lower risk (HR, 0.72) than normal dippers. For CVEs, heterogeneity was low for systolic night-to-day ratio and reverse/reduced dipping and moderate for extreme dippers. Quality of included studies was moderate to high, and publication bias was undetectable. In conclusion, in this largest meta-analysis of hypertensive patients, the nocturnal BP fall provided substantial prognostic information, independent of 24-hour SBP levels.

Heart Disease and Stroke Statistics—2017 Update: A Report From the American Heart Association

“…26 These phenotypes are associated with increased CVD risk, although there are few published data on the prognostic importance of these phenotypes in African Americans. 27 …”

Short-term variability and nocturnal decline in ambulatory blood pressure in normotension, white-coat hypertension, masked hypertension and sustained hypertension: a population-based study of older individuals in Spain

“…It has been reported that nondipping and diminished decline in nocturnal BP is associated with organ damage and poor cardiovascular outcomes both in population studies and in hypertensive patients. [46][47][48][49] It is noteworthy that in patients with pharmacological treatment, we did not observe any differences in nocturnal BP declines between groups. So, it is possible that antihypertensive treatment may affect nocturnal BP decline independent of mean BP.…”

Novel Approaches to Investigate One-Carbon Metabolism and Related B-Vitamins in Blood Pressure

“…Salles et al conducted a large meta-analysis in over three continents to investigate the effect of various dipping patterns on cardiovascular events and stroke [106]. Compared to the normal dipping pattern, individuals with any other dipping pattern at night were found to be at an increased risk of cardiovascular events (OR 1.40, 95% CI 1.20–1.63) and in particular stroke (OR 1.43, 95% CI 1.15–1.77).…”