Nocturnal blood pressure: the dark side of white-coat hypertension

Controversies in Hypertension III: Dipping, Nocturnal Hypertension, and the Morning Surge

A comprehensive approach to hypertension requires out-of-office determinations by home and/or ambulatory monitoring. The 4 phenotypes comparing office and out-of-office pressures in treated and untreated patients include normotension, hypertension, white-coat phenomena, and masked phenomena. Components of out-of-office pressure may be equally as important as mean values. Nighttime pressures are normally 10 - 20% lower than daytime (normal "dipping"). Abnormalities include dipping more than 20% (extreme dippers), less than 10 % (non-dippers), or rising above daytime (risers) and have been associated with elevated cardiovascular risk. Nighttime pressure may be elevated (nocturnal hypertension) in isolation or together with daytime hypertension. Isolated nocturnal hypertension theoretically changes white-coat hypertension to true hypertension and normotension to masked hypertension. Pressure normally peaks in the morning hours ("morning surge") when cardiovascular events are most common. Morning hypertension may result from residual nocturnal hypertension or an exaggerated surge and has been associated with enhanced cardiovascular risk, especially in Asian populations. Randomized trials are needed to determine whether altering therapy based solely on either abnormal dipping, isolated nocturnal hypertension, and/or an abnormal surge is justified.

Simple predictive score for nocturnal hypertension and masked nocturnal hypertension using home blood pressure monitoring in clinical practice

OBJECTIVE

The decision whether to measure night-time blood pressure (BP) is challenging as these values cannot be easily evaluated because of problems with measurement devices and related stress. Using the nationwide, practice-based Japan Morning Surge-Home BP Nocturnal BP study data, we developed a simple predictive score that physicians can use to diagnose nocturnal hypertension.

METHODS

We divided 2765 outpatients (mean age 63 years; hypertensive patients 92%) with cardiovascular risks who underwent morning, evening, and night-time home BP (HBP) measurements (0200, 0300, and 0400 h) into a calibration group ( n  = 2212) and validation group ( n  = 553). We used logistic-regression models in the calibration group to identify the predictive score for nocturnal hypertension (night-time HBP ≥120/70 mmHg) and then evaluated the score's predictive ability in the validation group.

RESULTS

In the logistic-regression model, male sex, increased BMI) (≥25 kg/m 2 ), diabetes, elevated urine-albumin creatinine ratio (UACR) (≥30 mg/g Cr), elevated office BP (≥140/90 mmHg) and home (average of morning and evening) BP (≥135/85 mmHg) had positive relationships with nocturnal hypertension. The predictive scores for nocturnal hypertension were 1 point (male, BMI, and UACR); 2 points (diabetes); 3 points (office BP ≥140/90 mmHg); 6 points (home BP ≥135/85 mmHg); total 14 points. Over 75% of the nocturnal hypertension cases in the validation group showed at least 10 points [AUC 0.691, 95% CI (0.647-0.735)]. We also developed a score for masked nocturnal hypertension, that is, nocturnal hypertension despite controlled daytime HBP.

CONCLUSION

We developed a simple predictive score for nocturnal hypertension that can be used in clinical settings and for diagnoses.

Nighttime mean arterial pressure is associated with left ventricular hypertrophy in white‐coat hypertension

White‐coat hypertension (WCH) is associated with increased cardiovascular risks. To investigate the relationship between WCH and left ventricular hypertrophy (LVH), the authors recruited 706 participants who underwent anthropometric measurements, blood laboratory analysis, 24h ambulatory blood pressure monitoring (ABPM), and echocardiography. The authors defined WCH as elevated office BP but normal ABPM over 24h, daytime, and nighttime periods. The authors compared the proportion of LVH between the true normotension (NT) and the WCH population, and further assessed the associations between BP indexes and LVH in the two groups, respectively. The proportion of LVH was significantly higher in the WCH group than in NT participants (19.70% vs. 13.12%, P = .036). In the NT group, 24h SBP, 24h PP, daytime SBP, daytime PP and SD of nighttime SBP were associated with LVH after adjustment for demographic and blood biochemical data (all P < .05). In the WCH population, LVH was associated with 24h SBP, nighttime SBP, nighttime MAP, and office SBP after adjustment (all P < .05). However, on forward logistic regression analysis with all the BP indexes listed above, only 24h SBP (OR = 1.057, 1.017–1.098, P < .001) in the NT group, and nighttime MAP (OR = 1.114, 1.005–1.235, P < .05) and office SBP (OR = 1.067, 1.019–1.117, P < .001) in the WCH group were still significantly associated with LVH. Our study suggests that the proportion of LVH is higher in WCH patients than in the NT population. Furthermore, elevated nighttime MAP and office SBP may play critical roles in the development of LVH in the WCH population.

White-Coat Hypertension: Pathophysiological and Clinical Aspects: Excellence Award for Hypertension Research 2020

Few issues of modern cardiovascular medicine have been as controversial as the relationship between white-coat hypertension (WCH), that is, a common condition in which office blood pressure is elevated while out-of-office blood pressure (ambulatory blood pressure or home blood pressure) is normal. While earlier studies showed no increased risk of cardiovascular events in WCH compared with the normotensive state, more recent studies have changed this conclusion by showing that an increased cardiovascular risk represents a trait of this hypertensive phenotype. The present article will review a number of issues related to WCH, that is, its definition, pathophysiological background, clinical alterations, and prognostic significance. This will be done by considering the available evidence published during the last decades, with special focus on the data collected in PAMELA (Pressioni Arteriose Monitorate e Loro Associazioni)-a research project performed with a cross-sectional and longitudinal design, which has provided a series of novel clinical information on WCH throughout the years. The final part of the article will discuss the therapeutic implications of the abovementioned evidence, as well as some controversial or still undefined issues related to WCH, whose investigation will be an important goal to pursue by future research.