Reproducibility of blood pressure dipping: Relation to day-to-day variability in sleep quality

Previous studies of the reproducibility of blood pressure (BP) dipping have yielded inconsistent results. Few have examined factors that may influence day-to-day differences in dipping. Ambulatory BP monitoring was performed on three occasions, approximately 1 week apart, in 115 untreated adult subjects with elevated clinic BPs. The mean ± standard deviation BP dip was 18 ± 7/15 ± 5 mm Hg (sleep/awake BP ratio = 0.87 ± 0.05/0.82 ± 0.06), with a median (interquartile range) day-to-day variation of 5.2 (3.1–8.1)/4.3 (2.8–5.6) mm Hg. There was no decrease in variability with successive measurements. The reproducibility coefficient (5.6 [95% confidence interval, 5.1–6.1] mm Hg) was greater and the intraclass correlation coefficient (0.53 [95% confidence interval, 0.42–0.63]) was smaller for the systolic dip than for 24-hour or awake systolic BPs, suggesting greater day-to-day variability in dipping. Variability in systolic dipping was greater in subjects with higher awake BP, but was not related to age, gender, race, or body mass index. Within individuals, day-to-day variations in dipping were related to variations in the fragmentation index (P < .001), a measure of sleep quality. Although mean 24-hour and awake BPs were relatively stable over repeated monitoring days, our study confirms substantial variability in BP dipping. Day-to-day differences in dipping are related to sleep quality.     

Association between sleep disorders and morning blood pressure in hypertensive patients

Sleep disorders are known to increase the risk of hypertension, yet few studies have investigated the relation between sleep disorders and morning blood pressure (BP). This study aimed to determine, whether the morning BP is associated with sleep quality and sleep-disordered breathing. A total of 144 hypertensive patients were included in this cross-sectional study. Each subject underwent anthropometric measurements, biochemical testing, 24-h ambulatory BP monitoring, and polysomnography (PSG). Sleep quality and sleep-disordered breathing were determined by PSG parameters of sleep architecture and sleep respiratory. There were no significant differences between subjects with and without morning hypertension in the parameters of sleep architecture and sleep respiratory. In multiple regression analysis, morning BP was independently associated with night-time BP and morning BP surge, but not with the parameters of sleep architecture and sleep respiratory. Further analysis showed that both night-time BP and morning BP surge were independently associated with the sleep respiratory parameters. In conclusion, sleep-disordered breathing might indirectly affect the morning BP by elevated night-time BP, yet neither poor sleep quality nor sleep-disordered breathing was major determinants of elevated morning BP in hypertensive patients.     

Visit‐to‐visit blood pressure variability and sleep architecture

Visit‐to‐visit blood pressure (BP) variability (BPV) is an independent risk factor of cardiovascular disease (CVD). Sleep architecture characterizes the distribution of different stages of sleep and may be important in CVD development. We examined the association between visit‐to‐visit BPV and sleep architecture using in‐lab polysomnographic data from 3,565 patients referred to an academic sleep center. BPV was calculated using the intra‐individual coefficient of variation of BP measures collected 12 months before the sleep study. We conducted multiple linear regression analyses to assess the association of systolic and diastolic BPV with sleep architecture—rapid eye movement (REM) and non‐rapid eye movement (NREM) sleep duration.Our results show that systolic BPV was inversely associated with REM sleep duration (p = .058). When patients were divided into tertile groups based on their BPV, those in the third tertile (highest variability) spent 2.7 fewer minutes in REM sleep than those in the first tertile (lowest variability, p = .032), after adjusting for covariates. We did not find an association of systolic BPV with other measures of sleep architecture. Diastolic BPV was not associated with sleep architecture either. In summary, our study showed that greater systolic BPV was associated with lower REM sleep duration. Future investigation is warranted to clarify the directionality, mechanism, and therapeutic implications.     

Subjective sleep quality,blood pressure,and hypertension: a meta‐analysis

Sleep quality is an important aspect of sleep, but no meta‐analysis has elucidated its relationship with blood pressure (BP) and hypertension. A meta‐analysis was conducted in October 2016 using multiple databases, including Embase and Medline. Studies that assessed subjective sleep quality and BP or hypertension were included. Upon full‐text evaluation, 29 articles from 45 041 patients were selected, of which 22 articles were included in the meta‐analysis and seven were presented narratively. Poor sleep quality was significantly associated with a greater likelihood of hypertension (odds ratio, 1.48; P value = .01). Poor sleepers had higher average systolic BP (mean difference = 4.37, P value = .09) and diastolic BP (mean difference = 1.25, P value = .32) than normal sleepers without statistical significance. Patients with hypertension had significantly worse sleep quality scores (mean difference = 1.51, P value < .01), while BP dippers had significantly better scores (mean difference = −1.67, P value < .01). The findings highlight the relationship between sleep quality and hypertension.     

Sleep quality and blood pressure dipping in obstructive sleep apnea

Background:Obstructive sleep apnea (OSA) is associated with poor sleep quality and a high incidence of nondipping. The aim of this study was to determine the association of sleep quality and nocturnal blood pressure (BP) dipping in an OSA population.Methods:A total of 44 untreated subjects with mild to severe OSA underwent overnight-attended polysomnography and 24-h ambulatory BP monitoring. Subjects were off antihypertensive medication. The percentage of slow wave sleep, percentage of time awake after sleep onset during the sleep period, sleep efficiency, and arousal index were chosen as measurements of sleep quality. Dipping was evaluated using the change in systolic BP, diastolic BP, and mean arterial pressure. Patients were classified as dippers and nondippers based on a nocturnal drop in mean arterial pressure > 10%. Differences between groups were evaluated by independent sample t tests. Pearson correlation and linear regression were used to evaluate the association of sleep quality and dipping.Results:There were no differences between dippers and nondippers with regard to body mass index, age, or respiratory disturbance index. A total of 84% were nondippers. No difference was found between dippers and nondippers in sleep quality. None of the sleep quality measures correlated with the measurements of dipping. In multiple regression analyses, the percentage of slow wave sleep and arousal index each independently predicted only a small percentage of the variance (approximately 10%) of nocturnal DBP dipping.Conclusions:The prevalence of nondipping was very high in a population of untreated patients with mild to severe OSA. Nonetheless, sleep quality did not appear to be related to BP dipping.     

阻塞性睡眠呼吸暂停对动态血压影响的研究

目的　探讨阻塞性睡眠呼吸暂停 (OSA)夜间低氧血症对动态血压变化的影响。方法　选择阻塞性睡眠呼吸暂停综合征 (OSAS)患者 60例和正常对照组 2 0例进行多导睡眠图检查和 2 4h血压监测。结果　轻度OSAS患者的动态血压及其昼夜节律的改变与正常对照组相比无显著性差异 ;中度OSAS患者的nMDP及血压昼夜节律与正常对照组相比已有显著性差异 ;而重度OSAS组的动态血压改变则更加明显 ,2 4hMDP、2 4hMAP、dMSP、dMDP、dMAP、nMSP、nMDP、nMAP均明显高于对照组 ,其中 2 4hMDP、dMDP、dMAP、nMSP、nMDP与轻、中度组比较有显著性差异 ,同时夜间血压下降节律紊乱 ,昼夜血压差值减小。OSAS患者 2 4hMDP、dMDP、nMSP、nMDP、nMAP与睡眠呼吸暂停低通气指数 (AHI)呈显著正相关 ,而 2 4hMSP、2 4hMAP、nMSP、nMAP、ΔSBP、ΔDBP与睡眠中经皮血氧饱和度(SpO2 )降低大于 0 0 4的总次数、SpO2 低于 0 90的时间均呈正相关 ,而与睡眠中SpO2 最低值、SpO2 平均值呈负相关。结论　OSAS患者各期血压的平均水平与AHI、呼吸暂停持续时间及SpO2 降低的程度显著相关 ,OSAS的病情越重 ,这种血压变化及昼夜节律改变越显著     

阻塞性睡眠呼吸暂停低通气综合征患者血浆神经肽Y水平与睡前及晨起血压的相关性

目的 探讨阻塞性睡眠呼吸暂停低通气综合征(OSAHS)患者血浆神经肽Y(NPY)浓度与患者睡前及晨起血压水平的相关性.方法 分组:肥胖OSAHS患者32例(OSAHS组)、非OSAHS肥胖者26例(单纯肥胖组)和体质量正常的健康成人27名(正常对照组).其中OSAHS组和单纯肥胖组接受多导睡眠仪(PSG)监测.血浆NPY的浓度采用酶联免疫吸附试验(ELISA)法测定.结果 OSAHS组血浆NPY浓度显著高于单纯肥胖组(P＜0.05)及正常对照组(P＜0.01).OSAHS患者睡前舒张压、晨起收缩压及舒张压比单纯肥胖组明显升高,差异有统计学意义.相关分析显示,OSAH S组血浆NPY浓度与患者睡前舒张压、晨起收缩压及舒张压呈正相关(P值分别为0.049、0.017、0.006).结论 OSAHS组NPY水平升高,NPY对OSAHS患者血压尤其晨起血压升高起到一定促进作用.     

Poor sleep is responsible for the impaired nocturnal blood pressure dipping in elderly hypertensive: A cross-sectional study of elderly

Objective: This study was aimed to assess whether sleep disorder was associated with an increased risk of less nocturnal blood pressure (BP) dipping in elderly patients with hypertension.

Methods: Cases were 1006 patients, aged >60 years, who were admitted to hospital with diagnosed hypertension during 2016–2017, and were divided into three groups with the systolic nocturnal BP dipping of 10%, and 0% as the cut-off value. The patients’ sleep was evaluated by Pittsburgh sleep quality index (PSQI).

Results: Compared to non-dipper BP rhythm patients (n = 382) and dipper BP rhythm patients (n = 132), reverse dipper patients (n = 492) exhibited higher PSQI score and had higher scores on six components with the exception of use sleep drug (p < 0.05). Multivariate logistic regression indicated that poor sleep, which was defined as high score of PSQI or its seven components, was associated with prevalence of reverse dipper in elderly hypertensive (odds ratio (OR) = 1.17, (95% confidence interval (CI), 1.13–1.21, p < 0.05) after adjusting for risk factors of hypertension. Multiple linear regression analysis showed that there was a significant negative correlation between PSQI score (include its seven components) and nocturnal BP dipping value after adjusting for risk factors of hypertension (β = ?0.584, p < 0.001).

Conclusions: In elderly patients with hypertension, poor sleep quality individuals were more prone to reverse dipper BP rhythm. Even adjusting for the effect of known risk factors of hypertension, poor sleep may contribute to attenuated BP dipping in elderly hypertensive.     

Mechanisms of pulse pressure amplification dipping pattern during sleep time: the SAFAR study

The difference in pulse pressure (PP) between peripheral arteries and the aorta, called pulse pressure amplification (PPamp), is a well-described physiological phenomenon independently associated with cardiovascular events. Recent studies suggest that it exhibits circadian variability. Our aim was to detect the factors associated with the circadian variability of PPamp. In 497 consecutive subjects (aged 54 years, 56.7% male, 79.7% hypertensives), we assessed the circadian pattern of peripheral and central arterial hemodynamics by 24-hour evaluation of brachial and aortic blood pressure (BP), augmentation index (AI), and pulse wave velocity (PWV) using a validated oscillometric device (Mobil-O-Graph). All parameters exhibited a circadian variation. Sleep dipping (decrease) pattern was observed for PPamp, brachial and aortic systolic BP, mean BP, and PWV, whereas a rising pattern (higher sleep than wake values) was observed for brachial PP, aortic PP, and AI. The factors independently associated with the less sleep dipping in PPamp were older age, lower height, the use of antihypertensive medication, and sleep decrease in arterial stiffness (PWV), whereas female gender, the presence of hypertension, sleep increase of pressure wave reflections (AI), sleep decrease in heart rate, and mean BP were associated with a greater sleep-dipping in PPamp. These data provide further pathophysiological understanding of the mechanisms leading to PPamp dipping. Several implications regarding the clinical use of the aortic and brachial BP, especially during sleep time, are raised that should be addressed in future research.     

Association of obstructive sleep apnea with arterial stiffness and nondipping blood pressure in patients with hypertension

Whether sex influences the association of obstructive sleep apnea (OSA) with markers of cardiovascular risk in patients with hypertension is unknown. In this study, 95 hypertensive participants underwent carotid‐femoral pulse wave velocity, 24‐hour ambulatory blood pressure monitoring, echocardiogram, and polysomnography after a 30‐day standardized treatment with hydrochlorothiazide plus enalapril or losartan. OSA was present in 52 patients. Compared with non‐OSA patients, pulse wave velocity values were higher in the OSA group (men: 11.1±2.2 vs 12.7±2.4 m/s, P=.04; women: 11.8±2.4 vs 13.2±2.2 m/s, P=.03). The proportion of diastolic dysfunction was significant in men and women with OSA. Compared with non‐OSA patients, nondipping systolic blood pressure in OSA was higher in men (14.3% vs 46.4%) and in women (41.4% vs 65.2%). OSA was independently associated with pulse wave velocity (β=1.050; P=.025) and nondipping systolic blood pressure (odds ratio, 3.03; 95% confidence interval, 1.08–8.55; P=.035) in the regression analysis. In conclusion, OSA is independently associated with arterial stiffness and nondipping blood pressure in patients with hypertension regardless of sex.     

Nocturnal blood pressure surge in seconds is associated with arterial stiffness independently of conventional nocturnal blood pressure variability in suspected obstructive sleep apnea patients

Nocturnal blood pressure (BP) surge in seconds (sec-surge), which is characterized as acute transient BP elevation over several tens of seconds is induced by obstructive sleep apnea (OSA) and OSA-related sympathetic hyperactivity. The authors assessed the relationship between sec-surge and arterial stiffness in 34 nocturnal hypertensive patients with suspected OSA (mean age 63.9 ± 12.6 years, 32.4% female). During the night, they had beat-by-beat (BbB) BP and cuff-oscillometric BP measurements, and brachial-ankle pulse wave velocity (baPWV) was assessed as an arterial stiffness index. Multiple linear regression analysis revealed that the upward duration (UD) of sec-surge was significantly associated with baPWV independently of nocturnal oscillometric systolic BP variability (β = .365, p = .046). This study suggests that the UD of sec-surge, which can only be measured using a BbB BP monitoring device, may be worth monitoring in addition to nocturnal BP level.     

Long sleep duration and cardiovascular disease: Associations with arterial stiffness and blood pressure variability

Although short and long sleep duration are both risk factors of cardiovascular disease (CVD), the recent meta‐analyses have been shown that long sleep duration was closely associated with CVD mortality. While the specific mechanism underlying the association between long sleep duration and CVD remains unclear, long sleep duration was shown to be associated with arterial stiffness and blood pressure variability (BPV) in many Asian populations. This review article will focus on the pathophysiology of long sleep duration, arterial stiffness, BPV and their effects on CVD. To set the stage for this review, we first summarize the current insights for the relationship between long sleep duration and CVD in relation to arterial stiffness and BPV.     

高血压合并阻塞性睡眠呼吸暂停综合征患者昼夜血压的变化

目的研究轻中度高血压合并阻塞性睡眠呼吸暂停综合征(OSAS)患者昼夜血压变化的特点。方法入选心功能(NHYA)Ⅰ级的轻中度高血压患者177例,经多导睡眠呼吸监测后,按睡眠呼吸暂停指数分为4组,单纯高血压组(A组)42例,高血压合并轻度OSAS组(B组)66例,高血压合并中度OSAS组(C组)25例和高血压合并重度OSAS组(D组)44例,进行24 h动态血压监测。结果 D组患者昼间和夜间血压水平明显高于A组(P<0.05,P<0.01),与A组比较,B、C和D组夜间舒张压显著升高(P<0.05,P<0.01)。夜间低血氧水平与醒时、醒后舒张压、昼间、夜间收缩压和舒张压呈负相关(P<0.05)。结论轻中度高血压合并OSAS患者的夜间舒张压更高,合并重度OSAS的高血压患者全天血压水平均明显高于单纯高血压患者,血压升高幅度与夜间低氧血症程度呈负相关。     

Stress, menopausal status and nocturnal blood pressure dipping patterns among hypertensive women

BACKGROUND:

A less than 10% decline in blood pressure during the night is known as a nondipping blood pressure (BP) pattern. Nondipping BP has been shown to be associated with target organ damage and poorer cardiovascular outcomes. Additionally, some evidence suggests that hypertensive nondipping women are at greater risk for target organ damage than hypertensive nondipping men.

OBJECTIVE:

To determine whether stress, demographics, menopausal status or sleep quality are associated with nondipping BP among hypertensive women.

METHODS:

A cross-sectional study design was used to describe the relationship between stress and dipping status among a sample of hypertensive women and to describe the sample by age, ethnicity, marital status, menopausal status, current medications and sleep quality.

RESULTS:

The study sample consisted of 47 women (mean [± SD] age 57±13.9 years) with essential or office hypertension who underwent 24 h ambulatory BP monitoring, and completed stress and sleep quality measurements. Thirty-one women (66%) were classified as dippers and 16 (34%) were classified as nondippers. Nondippers were older (P=0.04), postmenopausal (P=0.003) and had lower stress scores (P=0.02) than their dipper counterparts. Postmenopausal status significantly predicted nondipping (OR 16; 95% CI 1.9 to 136.4).

CONCLUSION:

These findings were of interest given that some women had a nondipping BP pattern and significantly lower stress scores. It is possible that there are fundamentally different physiological mechanisms that explain this nondipping phenomenon. In the future, the identification of specific hemodynamic mechanisms associated with nondipping could potentially influence the choice of antihypertensive treatment regimens for nondipper hypertensive patients.     

老年高血压病并发阻塞性睡眠呼吸暂停综合征患者血压特点及与炎症因子的关系

目的研究并发中重度阻塞性睡眠呼吸暂停综合征（obstructive sleep apnea syndrome,OSAS）的老年高血压患者血压的变化情况及炎症因子的水平,从而揭示此类患者的疾病特点。方法将60例年龄大于60岁的研究对象根据诊所血压、24 h动态血压和多导睡眠图监测结果分为单纯高血压病组（n=30）和并发OSAS组（高血压病并发中重度睡眠呼吸暂停综合征,n=30）。用ELISA法测定白介素-6（IL-6）、sCD40L、超敏C反应蛋白（hs-CRP）、可溶性细胞间黏附分子1（ICAM-1）及血管细胞黏附分子1（VCAM-1）的浓度。结果①并发OSAS组中非杓型血压的发生率为67%,明显高于单纯高血压组的发生率37%（P<0.05）。②并发OSAS组24 h、白天、夜间平均脉压（mean arterial blood pressure,MAP）分别为（51±13）mmHg（1 mmHg=0.133 kPa）,（50±13）mmHg和（51±17）mmHg均明显高于单纯高血压组（45±7）mmHg,（46±8）mmHg和（44±6）mmHg,并有统计学意义（P<0.05）。③并发OSAS组的IL-6、sCD40L、hs-CRP、ICAM-1、VCAM-1浓度明显高于单纯高血压组。④并发OSAS组的hs-CRP、ICAM-1、VCAM-1浓度变化与呼吸紊乱指数、睡眠血氧下降程度正相关（r=0.852,P<0.05）。hs-CRP与MAP呈正相关（P<0.01）,ICAM-1与夜间血压下降率呈负相关（P<0.05）。结论中重度睡眠呼吸暂停影响老年人血压昼夜节律的变化,同时对脉压产生明显影响,炎症反应也明显加重。