Association between sleep disorders and morning blood pressure in hypertensive patients

Sleep and blood pressure variability: A systematic literature review

BACKGROUND

Blood pressure variability (BPV) is a prognostic marker of cardiovascular disease (CVD). Sleep is recognized as a significant risk factor for CVD; however, little is known about the relationship between sleep characteristics and BPV.

OBJECTIVE

In this systematic review, we aimed to (1) describe methods used to measure BPV and sleep and (2) describe the current evidence in the literature on the association between sleep and BPV.

METHODS

A systematic search was conducted using the search terms "sleep" AND ("blood pressure variability" OR "ambulatory blood pressure monitor") in CINAHL, PubMed, Web of Science, and PsycINFO databases.

RESULTS

Twenty-two studies were included in this systematic review. Sleep was measured using various methods, including polysomnography, actigraphy, sleep diaries, and questionnaires, while BPV was measured over various time intervals using different monitoring devices such as a beat-to-beat blood pressure (BP) monitoring device, a 24-h ambulatory BP monitor, or an automatic upper arm BP monitor. The studies demonstrated mixed results on the associations between sleep parameters (sleep quality, architecture, and duration) and increased BPV.

CONCLUSIONS

Although the mechanisms that explain the relationship between sleep and BPV are still unclear, accumulating evidence suggests potential associations between increased BPV with poor sleep quality and longer sleep duration. Given the recent development of sleep and BP monitoring technologies, further research is warranted to assess sleep and BPV under free-living conditions. Such studies will advance our understanding of complex interactions between sleep and CVD risk.

Psychological distress, forced awakening, and morning blood pressure surge

BACKGROUND

Morning blood pressure surge (MBPS) has been recognized as an independent predictor of cardiovascular disease events. Psychological distress, including anxiety, depression, and perceived stress, and behavioral risk factors, such as poor sleep quality, have been associated with increased MBPS. Elevations in sympathetic activity induced by forced awakening may also contribute to further increases in MBPS. Yet, no examination of the interrelationships among psychological distress, sleep quality, awakening mode (natural vs. forced awakenings), and MBPS has been undertaken.

OBJECTIVE

This pilot study aimed: (1) to examine if MBPS differs by awakening mode and (2) to investigate whether psychological distress is associated with MBPS difference between natural and forced awakenings, independent of sleep quality.

METHODS

Thirty-two healthy adults were included in this cross-sectional study. Blood pressure was measured using a beat-to-beat blood pressure monitor over two nights, consisting of one night of natural awakening and one night of forced awakening. Psychological distress and sleep quality were assessed using questionnaires. We conducted paired t-tests (aim 1) and multiple linear regressions (aim 2).

RESULTS

MBPS was significantly greater during forced awakening compared with natural awakening. In addition, the MBPS difference between natural and forced awakenings was significantly greater in participants with higher anxiety levels, independent of sleep quality.

CONCLUSION

We found that augmentation of MBPS by forced awakening was significantly greater in individuals who reported higher anxiety levels. Additional research is needed to examine the potential impacts of forced awakening and anxiety on MBPS in a larger sample of individuals at risk for cardiovascular disease.

Association and Risk Factors for Obstructive Sleep Apnea and Cardiovascular Diseases: A Systematic Review

Obstructive sleep apnea (OSA) is a serious, potentially life-threatening condition. Epidemiologic studies show that sleep apnea increases cardiovascular diseases risk factors including hypertension, obesity, and diabetes mellitus. OSA is also responsible for serious illnesses such as congestive heart failure, stroke, arrhythmias, and bronchial asthma. The aim of this systematic review is to evaluate evidence for the association between OSA and cardiovascular disease morbidities and identify risk factors for the conditions. In a review of 34 studies conducted in 28 countries with a sample of 37,599 people, several comorbidities were identified in patients with severe OSA—these were: heart disease, stroke, kidney disease, asthma, COPD, acute heart failure, chronic heart failure, hyperlipidemia, thyroid disease, cerebral infarct or embolism, myocardial infarction, and psychological comorbidities including stress and depression. Important risk factors contributing to OSA included: age > 35 years; BMI ≥ 25 kg/m²; alcoholism; higher Epworth sleepiness scale (ESS); mean apnea duration; oxygen desaturation index (ODI); and nocturnal oxygen desaturation (NOD). Severe OSA (AHI ≥ 30) was significantly associated with excessive daytime sleepiness and oxygen desaturation index. The risk of OSA and associated disease morbidities can be reduced by controlling overweight/obesity, alcoholism, smoking, hypertension, diabetes mellitus, and hyperlipidemia.

Associations Between Relative Morning Blood Pressure, Cerebral Blood Flow, and Memory in Older Adults Treated and Controlled for Hypertension

[Figure: see text].

The disadvantage of morning blood pressure management in hypertensive patients

To investigate whether the control of morning blood pressure (MBP) reflects the control of blood pressure (BP) in other periods (daytime, nighttime and 24-hour) and to assess whether morning BP displays a closer association with subclinical target organ damage (TOD) than the BP measured in other periods.One thousand one hundred forty patients with primary hypertension who completed subclinical TOD detection and 24-hour ambulatory BP monitoring were included in the analysis. Pearson correlation analysis, Kappa consistency test, multiple linear regression analysis, and area under the receiver operating curve were used to analyze the data.Morning BP and daytime BP displayed good agreement, but not 24-hour BP , particularly the nighttime BP (all P < .001). Approximately 39.4% of the hypertensive patients receiving drug treatment who had achieved control of the morning BP presented masked nocturnal hypertension, which was associated with worse subclinical TOD. The BP measured in all periods correlated with subclinical TOD, and the correlation was more obvious in the treatment subgroup. However, morning BP did not independently affect subclinical TOD. Morning BP appeared to exhibit less discriminatory power than nighttime BP, particularly with respect to the urinary albumin to creatinine ratio.The use of morning BP for monitoring during hypertension management may not be enough. Masked uncontrolled nocturnal hypertension should be screened when morning BP is controlled.

Association of home blood pressure with sleep and physical and mental activity, assessed via a wristwatch-type pulsimeter with accelerometer in adults

This study aimed to examine the associations between home blood pressure (HBP) and sleep and activity assessed using data obtained via a wristwatch-type pulsimeter with accelerometer (Pulsense®) using original software. We recruited 28 elderlies and 40 employees aged 24-81 years who were not on hypotensive agents and sleeping drugs. Sleep, activity, and HBP were measured consecutively over a 5-7-day period. Body mass index (BMI), base heart rate (HR₀), and age showed significant correlation with HBP in a simple and multiple linear regression analysis. HR₀ was positively, and log deep sleep duration, negatively correlated with HBP in the adjusted multiple linear regression analysis. Physical and mental activities were negatively correlated with systolic blood pressure (SBP) in a simple linear regression, but high physical and mental activities tend to reduce deep sleep duration. Self-recorded sleep duration had no relationship with HBP. In conclusion, HR₀, BMI, age, deep sleep duration, and activity showed relationships with HBP. Using this type of wristwatch and observing daily sleep and activity data with HBP measurement may have important clinical implication.

Blood-pressure variability in patients with obstructive sleep apnea: current perspectives

Obstructive sleep apnea (OSA) is often associated with hypertension and other cardiovascular diseases. Blood pressure (BP) variability is part of the assessment of cardiovascular risk. In OSA, BP variability has been studied mainly as very short-term (beat-by-beat) and short-term (24-hour BP profile) variability. BP measured on consecutive heartbeats has been demonstrated to be highly variable, due to repeated peaks during sleep, so that an accurate assessment of nocturnal BP levels in OSA may require peculiar methodologies. In 24-hour recordings, BP frequently features a "nondipping" profile, ie, <10% fall from day to night, which may increase cardiovascular risk and occurrence of major cardiovascular events in the nocturnal hours. Also, BP tends to show a large "morning BP surge", a still controversial negative prognostic sign. Increased very short-term BP variability, high morning BP, and nondipping BP profile appear related to the severity of OSA. Treatment of OSA slightly reduces mean 24-hour BP levels and nocturnal beat-by-beat BP variability by abolishing nocturnal BP peaks. In some patients OSA treatment turns a nondipping into a dipping BP profile. Treatment of arterial hypertension in OSA usually requires both antihypertensive pharmacological therapy and treatment of apnea. Addressing BP variability could help improve the management of OSA and reduce cardiovascular risk. Possibly, drug administration at an appropriate time would ensure a dipping-BP profile.