Objective sleep quality and night-time blood pressure in the general elderly population: a cross-sectional study of the HEIJO-KYO cohort

Reproducibility of sequential ambulatory blood pressure and pulse wave velocity measurements in normotensive and hypertensive individuals

OBJECTIVE

Errors in blood pressure (BP) measurement account for a large proportion of misclassified hypertension diagnoses. Ambulatory blood pressure monitoring (ABPM) is often considered to be the gold standard for measurement of BP, but uncertainty remains regarding the degree of measurement error. The aim of this study was to determine reproducibility of sequential ABPM in a population of normotensive and well controlled hypertensive individuals.

METHODS

Individual participant data from three randomized controlled trials, which had recorded ABPM and carotid-femoral pulse wave velocity (PWV) at least twice were combined ( n  = 501). We calculated within-individual variability of daytime and night-time BP and compared the variability between normotensive ( n  = 324) and hypertensive ( n  = 177) individuals. As a secondary analysis, variability of PWV measurements was also calculated, and multivariable linear regression was used to assess characteristics associated with blood pressure variability (BPV).

RESULTS

Within-individual coefficient of variation (CoV) for systolic BP was 5.4% (day) and 7.0% (night). Equivalent values for diastolic BP were 6.1% and 8.4%, respectively. No statistically significant difference in CoV was demonstrated between measurements for normotensive and hypertensive individuals. Within-individual CoV for PWV exceeded that of BP measurements (10.7%). BPV was associated with mean pressures, and BMI for night-time measurements. PWV was not independently associated with BPV.

CONCLUSION

The variability of single ABPM measurements will still yield considerable uncertainty regarding true average pressures, potentially resulting in misclassification of hypertensive status and incorrect treatment regimes. Repeated ABPM may be necessary to refine antihypertensive therapy.

Effect of sleep disturbance on biomarkers related to the development of adverse health outcomes: A systematic review of the human literature

Literature suggests that unrestricted and undisturbed sleep is vital for basic human function and performance; however, it is unclear as to what amount of sleep disturbance leads to dysregulation in biomarkers, which may underscore the development of adverse health effects. This systematic review aims to identify the amount of sleep disturbance that contributes to biomarker changes as a potential precursor to the development of adverse health effects. English-language comparative studies available in PubMed, Cochrane Central, EMBASE, and CINAHL databases from 1 January 1980 to 31 July 2021 were searched. Where possible, random-effects meta-analyses were used to examine the effect of sleep disturbances on adverse health effects. The risk of bias of individual studies was assessed using the Cochrane Risk of Bias Tool and the Risk of Bias of Nonrandomised Studies - of Exposures instruments and the certainty of the body of evidence for each outcome was assessed using the Grading of Recommendations Assessment, Development and Evaluation approach. The search identified 92 primary studies reporting on blood pressure, hypertension, heart rate, cardiac arrhythmia, cardiac output, waist circumference, cortisol, adrenaline, noradrenaline, immune system markers, glucose, insulin, cholesterol, and triglyceride levels. Although some meta-analyses suggested there may be an association between sleep disturbances and certain outcomes, the certainty in the evidence was very low due to concerns with risk of bias, inconsistency across exposures, populations, and imprecision in the estimates of effects. Further research is needed to explore the point at which types, levels and duration of sleep disturbances may begin to increase the risk of developing adverse health outcomes to inform and tailor health interventions.

Effects of ambulatory blood pressure monitoring on sleep in healthy, normotensive men and women

OBJECTIVES

To determine the effect of ambulatory blood pressure monitoring (ABPM) on sleep quality among healthy adults and to explore possible effect modification by demographics.

METHODS

We examined data from 192 relatively healthy young (median age: 31; 33% men, 18% with clinic BP >130/80 mmHg) participants in an observational study of sleep and arterial stiffness. Demographic/health questionnaires were completed. A wrist-based accelerometer assessed sleep for seven nights, and sleep duration, wakefulness after sleep onset (WASO), fragmentation (physical restlessness), midpoint, and efficiency were estimated. ABPM was conducted for one 36-h period, including one actigraphy night.

RESULTS

Within-subject comparisons indicated that WASO and fragmentation were higher, midpoint was later, and efficiency was lower on the ABPM night (Ps < 0.001-0.038). Neither age nor sex moderated these associations. Among older adults, a later midpoint and worse fragmentation were observed with ABPM (Ps = 0.002-0.010). There was also a main effect of sex: men demonstrated shorter sleep duration, greater WASO and fragmentation, and less efficiency than women (Ps = 0.002-0.046). With ABPM, women had worse fragmentation and a later midpoint (Ps = 0.002-0.049); for men, WASO and fragmentation were worse (Ps = 0.003-0.023). Importantly, this study does not address whether the effect of wearing ABPM on sleep in turn affects BP during sleep.

CONCLUSIONS

ABPM appears to modestly disturb actigraphy-assessed sleep among healthy adults. Researchers and clinicians should consider the downstream effects of performing ABPM and whether these effects are more pronounced in those who typically experience sleep disturbance.

Simultaneous self‐monitoring comparison of a supine algorithm‐equipped wrist nocturnal home blood pressure monitoring device with an upper arm device

A nocturnal home blood pressure (BP) monitoring device that measures nighttime BP levels accurately with less sleep disturbance is needed for the 24‐h management of hypertension. Here we conducted the first comparison study of simultaneous self‐monitoring by both a supine position algorithm‐equipped wrist nocturnal home BP monitoring device, the HEM‐9601T (NightView; Omron Healthcare) with a similar upper arm device, the HEM‐9700T (Omron Healthcare) in 50 hypertensive patients (mean age 68.9 ± 11.3 years). Both devices were worn on the same non‐dominant arm during sleep over two nights. The patients self‐measured their nighttime BP by starting nocturnal measurement mode just before going to bed. In total, 694 paired measurements were obtained during two nights (7.2 ± 1.5 measurements per night), and the mean differences (±SD) in systolic BP between the devices was 0.2 ± 10.2 mmHg (p = .563), with good agreement. In the comparison of nighttime BP indices, the difference in average SBP at 2:00, 3:00, and 4:00 AM and the average SBP of 1‐h interval measurements was −0.5 ± 5.5 mmHg (p = .337), with good agreement. The HEM‐9601T substantially reduced sleep disturbance compared to the upper arm‐type device. The newly developed HEM‐9601T (NightView) can thus accurately measure BP during sleep without reducing the wearer's sleep quality.

Nocturnal blood pressure measured by home devices: evidence and perspective for clinical application

: Studies using ambulatory blood pressure (BP) monitoring have shown that BP during night-time sleep is a stronger predictor of cardiovascular outcomes than daytime ambulatory or conventional office BP. However, night-time ambulatory BP recordings may interfere with sleep quality because of the device cuff inflation and frequency of measurements. Hence, there is an unmet need for obtaining high quality BP values during sleep. In the last two decades, technological development of home BP devices enabled automated BP measurements during night-time. Preliminary data suggest that nocturnal home BP measurements yield similar BP values and show good agreement in detecting nondippers when compared with ambulatory BP monitoring. Thus, nocturnal home BP measurements might be a reliable and practical alternative to ambulatory BP monitoring to evaluate BP during sleep. As the use of home BP devices is widespread, well accepted by users and has relatively low cost, it may prove to be more feasible and widely available for routine clinical assessment of nocturnal BP. At present, however, data on the prognostic relevance of nocturnal BP measured by home devices, the optimal measurement schedule, and other methodological issues are lacking and await further investigation. This article offers a systematic review of the current evidence on nocturnal home BP, highlights the remaining research questions, and provides preliminary recommendations for application of this novel approach in BP management.

Reduced sleep efficiency, measured using an objective device, was related to an increased prevalence of home hypertension in Japanese adults

Few studies have reported the relationship between reduced sleep efficiency and the prevalence of hypertension independent of sleep duration in Japan. This study aimed to evaluate whether reduced sleep efficiency, measured using an objective device for >1 week, was related to an increased prevalence of hypertension independent of sleep duration in the general Japanese population. We conducted a cross-sectional study of 904 participants aged ≥20 years who lived in Miyagi Prefecture, Japan. Sleep efficiency was measured using a contactless biomotion sleep sensor for 10 continuous days. The participants were classified into two groups according to their sleep efficiency: reduced (<90%) or not reduced (≥90%). Hypertension was defined as morning home blood pressure ≥135/85 mmHg or self-reported treatment for hypertension. Multivariable logistic regression models were used to obtain odds ratios (ORs) and 95% confidence intervals (CIs) to assess the relationship between sleep efficiency and hypertension adjusted for potential confounders. The results showed that two hundred and ninety-four individuals (32.5%) had reduced sleep efficiency, and 331 (36.6%) had hypertension. Individuals with reduced sleep efficiency had a higher body mass index and shorter sleep duration. In the multivariable analysis, reduced sleep efficiency was significantly related to an increased prevalence of hypertension (OR, 1.62; 95% CI, 1.15–2.28). In conclusion, reduced sleep efficiency was significantly related to an increased prevalence of hypertension in Japanese adults. Improvements in sleep efficiency may be important to reduce blood pressure in Japanese adults.

Diminished circadian blood pressure variability in elderly individuals with nuclear cataracts: cross-sectional analysis in the HEIJO-KYO cohort

The present study aimed to determine the relationship between cataract subtypes and circadian blood pressure (BP) variability in elderly individuals. In this cross-sectional study of a community-based cohort, we assessed bilateral lens opacity using slit lamp photographs of 458 elderly individuals (mean age, 69.1 years). Cataract status was defined as a bilateral Lens Opacities Classification System III grade of ≥3 for nuclear cataract, ≥2 for cortical cataract, and ≥2 for posterior subcapsular cataract (PSC). Ambulatory BP monitoring was performed at 30-min intervals for 48 h. A nondipper pattern of BP was defined as a <10% decline in the mean nighttime systolic BP relative to the mean daytime systolic BP. The prevalence of nondipper patterns was 42.4% and 25.9% in the groups with nuclear cataracts (n = 66) and without cataracts for both eyes (n = 290), respectively. Multivariable logistic regression analysis adjusted for potential confounders revealed a significantly higher odds ratio (OR) for nondipper pattern in the group with nuclear cataract than in that without cataract (OR, 1.81; 95% confidence interval, 1.01-3.24; P = 0.047) but not in the group with cortical cataract (P = 0.61) or PSC (P = 0.95). In conclusion, circadian BP variability was significantly diminished in elderly individuals with nuclear cataracts but not in those with cortical cataracts or PSCs. These associations were independent of daytime light exposure, physical activity, and known risk factors of cataracts, such as aging, obesity, and diabetes.