Sleep and risk for high blood pressure and hypertension in midlife women: the SWAN (Study of Women's Health Across the Nation) Sleep Study

Association of Disrupted Delta Wave Activity During Sleep With Long-Term Cardiovascular Disease and Mortality

BACKGROUND

Delta wave activity is a prominent feature of deep sleep, which is significantly associated with sleep quality.

OBJECTIVES

The authors hypothesized that delta wave activity disruption during sleep could predict long-term cardiovascular disease (CVD) and CVD mortality risk.

METHODS

The authors used a comprehensive power spectral entropy-based method to assess delta wave activity during sleep based on overnight polysomnograms in 4,058 participants in the SHHS (Sleep Heart Health Study) and 2,193 participants in the MrOS (Osteoporotic Fractures in Men Study) Sleep study.

RESULTS

During 11.0 ± 2.8 years of follow-up in SHHS, 729 participants had incident CVD and 192 participants died due to CVD. During 15.5 ± 4.4 years of follow-up in MrOS, 547 participants had incident CVD, and 391 died due to CVD. In multivariable Cox regression models, lower delta wave entropy during sleep was associated with higher risk of coronary heart disease (SHHS: HR: 1.46; 95% CI: 1.02-2.06; P = 0.03; MrOS: HR: 1.79; 95% CI: 1.17-2.73; P < 0.01), CVD (SHHS: HR: 1.60; 95% CI: 1.21-2.11; P < 0.01; MrOS: HR: 1.43; 95% CI: 1.00-2.05; P = 0.05), and CVD mortality (SHHS: HR: 1.94; 95% CI: 1.18-3.18; P < 0.01; MrOS: HR: 1.66; 95% CI: 1.12-2.47; P = 0.01) after adjusting for covariates. The Shapley Additive Explanations method indicates that low delta wave entropy was more predictive of coronary heart disease, CVD, and CVD mortality risks than conventional sleep parameters.

CONCLUSIONS

The results suggest that delta wave activity disruption during sleep may be a useful metric to identify those at increased risk for CVD and CVD mortality.

Association between electroencephalogram-based sleep characteristics and physical health in the general adult population

We examined the associations between electroencephalogram (EEG)-based sleep characteristics and physical health parameters in general adults via a cross-sectional study recruiting 100 volunteers aged 30-59 years. Sleep characteristics were measured at home using a portable multichannel electroencephalography recorder. Using the k-means +  +  clustering method, according to 10 EEG-based parameters, participants were grouped into better (n = 39), middle (n = 46), and worse (n = 15) sleep groups. Comparing 50 physical health parameters among the groups, we identified four signals of difference (P < 0.05), including systolic (sBP) and diastolic blood pressure (dBP), γ-glutamyl transpeptidase (γ-GTP), and serum creatinine, where sBP reached a Bonferroni-corrected threshold (P < 0.001). The sBP was higher by 7.9 (95% confidence interval 1.9-13.9) and 15.7 (7.3-24.0) mmHg before adjustment and 5.4 (- 0.1-10.9) and 8.7 (1.1-16.3) mmHg after adjustment for age, sex, body mass index, smoking, drinking habits, and 3% oxygen desaturation index in the middle and worse sleep groups, respectively, than in the better group. As another approach, among 500 combinations of EEG-based and physical health parameters, there were 45 signals of correlation, of which 4 (N1% and sBP, dBP, γ-GTP, and triglycerides) reached a Bonferroni-corrected threshold (P < 0.0001). Thus, EEG-based sleep characteristics are associated with several physical health parameters, particularly sBP.

The effect of nonrestorative sleep on incident hypertension 1-2 years later among middle-aged Hispanics/Latinos

BACKGROUND

Insomnia is known to be a major risk factor for incident hypertension. Nonrestorative sleep (NRS), which refers to insufficiently rested sleep, has reported to associate with various diseases. This study aimed to investigate the longitudinal association between insomnia-related symptoms including NRS and incident hypertension 1-2 years later by age group (young, 18-39 years and middle-age, 40-64 years) using existing cohort data involving Hispanics/Latinos.

METHODS

This study included 1100 subjects who had participated in both the Hispanic Community Health Study/Study of Latinos and its follow-up study, the Sueño Ancillary Study, and met additional eligibility criteria. Incident hypertension was assessed by self-reported history and/or the use of antihypertensives. The Women's Health Initiative Insomnia Rating Scale (WHIIRS) was used to evaluate insomnia-related symptoms (difficulty initiating sleep, difficulty maintaining sleep, early morning awakening, difficulty returning to sleep, and NRS). Logistic regression analyses were conducted to assess the degree to which insomnia-related symptoms at baseline predicted incident hypertension.

RESULTS

Among the participants (64% middle-aged, 36% young adults), 140 (12.7%) developed hypertension during the follow-up period. Among the sleep-related symptoms, only NRS predicted incident hypertension after adjusting for sociodemographic factors and physical condition (odds ratio: 1.88, 95% confidence interval: 1.10-3.21, p = 0.022) in middle-aged adults. None of the insomnia-related symptoms were associated with incident hypertension in the young adults. No association was found between WHIIRS-defined insomnia (total score ≥ 9) and incident hypertension in middle-aged adults or young adults.

CONCLUSION

The present findings suggest the importance of focusing on NRS to help prevent the development of hypertension in middle-aged adults.

Vasomotor symptoms of menopause, autonomic dysfunction, and cardiovascular disease

Cardiovascular disease (CVD), the leading cause of death among US adults, is more prevalent in menopausal females compared with age-matched males. Vasomotor symptoms of menopause (VMS; hot flashes/flushes and night sweats) are common among females undergoing menopausal transition and have been associated with elevated blood pressure (BP) and increased CVD risk. Autonomic dysregulation of BP has been posited as a contributing factor to the elevated CVD risk in menopausal females with VMS. This review includes 1) a brief overview of the relationship between VMS and CVD, 2) mechanisms of hot flushes and their potential impact on short- and long-term BP regulation, and 3) how the disruption of autonomic function associated with VMS might provide a mechanistic pathway to CVD development. Finally, this review will highlight knowledge gaps and future directions toward better understanding of hot flush physiology and VMS contributions to CVD.

Association between blood pressure and parameters related to sleep disorders in Tabari cohort population

Background

Insomnia and other sleep disorders can cause an increase in blood pressure, thereby resulting in premature death. Regarding this, the present study was conducted to investigate the relationship between hypertension and parameters related to sleep disorders in Tabari cohort population.

Methods

In this cross-sectional study, the data from the enrollment phase of the Tabari cohort study were adopted. Tabari cohort is a part of the PERSIAN (Prospective Epidemiological Research Studies in Iran) cohort study. Data analysis was performed using descriptive and inferential statistics.

Results

Out of 10,255 patients enrolled in the Tabari cohort, 2,281 patients (22.2%) had hypertension. According to the results of univariable logistic regression test, the odds ratio of high blood pressure in patients with insomnia and hypersomnia is 1.22 (95% confidence interval [CI], 1.06–1.40) and 1.22 (95% CI, 1.01–1.47) times higher than normal sleep. This odds ratio was not significant after adjusting the effect of sex, age, body mass index, waist circumference, area residence, high-density lipoprotein cholesterol, triglyceride, and total cholesterol variables with multivariable logistic regression. Frequency of routine hypnotic medication usage (14.6% vs. 5.7%, P < 0.001), involuntary napping (25.3% vs. 19%, P < 0.001), and leg restlessness during sleep (14.8% vs. 11.7%, P < 0.001) was higher in hypertensive individuals than in nonhypertensive cases.

Conclusions

This study showed that sleep disorders prevalence are higher in hypertensive patients than nonhypertensive patients. Also, routine use of hypnotics was significantly higher medication in patients with hypertension compared to that in the nonhypertensive patients.

Association Between Sleep Microstructure and Incident Hypertension in a Population‐Based Sample: The HypnoLaus Study

Background

Poor sleep quality is associated with increased incident hypertension. However, few studies have investigated the impact of objective sleep structure parameters on hypertension. This study investigated the association between sleep macrostructural and microstructural parameters and incident hypertension in a middle‐ to older‐aged sample.

Methods and Results

Participants from the HypnoLaus population‐based cohort without hypertension at baseline were included. Participants had at‐home polysomnography at baseline, allowing assessment of sleep macrostructure (nonrapid eye movement sleep stages 1, 2, and 3; rapid eye movement sleep stages; and total sleep time) and microstructure including power spectral density of electroencephalogram in nonrapid eye movement sleep and spindles characteristics (density, duration, frequency, amplitude) in nonrapid eye movement sleep stage 2. Associations between sleep macrostructure and microstructure parameters at baseline and incident clinical hypertension over a mean follow‐up of 5.2 years were assessed with multiple‐adjusted logistic regression. A total of 1172 participants (42% men; age 55±10 years) were included. Of these, 198 (17%) developed hypertension. After adjustment for confounders, no sleep macrostructure features were associated with incident hypertension. However, low absolute delta and sigma power were significantly associated with incident hypertension where participants in the lowest quartile of delta and sigma had a 1.69‐fold (95% CI, 1.00–2.89) and 1.72‐fold (95% CI, 1.05–2.82) increased risk of incident hypertension, respectively, versus those in the highest quartile. Lower spindle density (odds ratio, 0.87; 95% CI, 0.76–0.99) and amplitude (odds ratio, 0.98; 95% CI, 0.95–1.00) were also associated with higher incident hypertension.

Conclusions

Sleep microstructure is associated with incident hypertension. Slow‐wave activity and sleep spindles, 2 hallmarks of objective sleep continuity and quality, were inversely and consistently associated with incident hypertension. This supports the protective role of sleep continuity in the development of hypertension.

Impact of smoking on sleep macro- and microstructure

OBJECTIVES

Existing data suggest that smoking may be associated with sleep disturbances. This study aimed to determine the association between smoking and both subjective and objective sleep quality.

METHODS

Cross-sectional analysis of sleep characteristics in 3233 participants from the population-based CoLaus-HypnoLaus cohort (52.2% women, mean age 56.6 ± 10.2 years) who completed questionnaires on sleep quality, of whom 1489 (46%) had a full polysomnography. Smoking data were self-reported; participants were classified by smoking status as current, former or never smokers. Primary outcomes were subjective sleep quality assessed by sleep questionnaires, and objective sleep quality based on polysomnography (sleep macrostructure), including power spectral analysis of the electroencephalogram on C4 electrode (sleep microstructure), quantifying the relative amount of delta power (1-4 Hz), a marker of sleep depth, and arousal-associated alpha power (8-12 Hz).

RESULTS

Current smokers had a shift toward faster sleep electroencephalogram activity with lower delta power in non-REM sleep compared with former and never smokers (-2.8 ± 0.4% and -2.4 ± 0.4%, respectively; both p < 0.001) and higher alpha power (+0.8 ± 0.2%; p < 0.001) compared with never smokers. There was a dose-dependent negative association between electroencephalogram delta power and smoking intensity (r² = -1.2 [-1.9, -0.5]; p = 0.001). Additionally, mean nocturnal oxygen saturation was lower in current smokers.

CONCLUSIONS

Current smokers had decreased objective sleep quality, with a dose-dependent association between smoking intensity and decrease in electroencephalogram delta power during non-REM sleep, in addition to an increase in alpha power. Considering the importance of sleep quality for wellbeing and health, these results provide further data to support smoking cessation.

Lifestyle interventions for the prevention and treatment of hypertension

Hypertension affects approximately one third of the world's adult population and is a major cause of premature death despite considerable advances in pharmacological treatments. Growing evidence supports the use of lifestyle interventions for the prevention and adjuvant treatment of hypertension. In this Review, we provide a summary of the epidemiological research supporting the preventive and antihypertensive effects of major lifestyle interventions (regular physical exercise, body weight management and healthy dietary patterns), as well as other less traditional recommendations such as stress management and the promotion of adequate sleep patterns coupled with circadian entrainment. We also discuss the physiological mechanisms underlying the beneficial effects of these lifestyle interventions on hypertension, which include not only the prevention of traditional risk factors (such as obesity and insulin resistance) and improvements in vascular health through an improved redox and inflammatory status, but also reduced sympathetic overactivation and non-traditional mechanisms such as increased secretion of myokines.

Cardiovascular prevention in women: a narrative review from the Italian Society of Cardiology working groups on 'Cardiovascular Prevention, Hypertension and peripheral circulation' and on 'Women Disease'

: Cardiovascular disease (CVD) is the leading cause of mortality and morbidity in women.Some authors highlighted that the female risk profile consists of traditional and emerging risk factors. Despite the lower prevalence of type 2 diabetes, years of life lost owing to the disease for women are substantially higher compared with men. In addition, pregnancy complicated by gestational diabetes represents a risk factor for CVD. Women with gestational diabetes have a higher prevalence of coronary artery disease that occur at a younger age and are independent of T2DM.Hypertension is an important cardiovascular risk factor in women. Estrogens and progesterone, known to have an impact on blood pressure levels, have also been proposed to be protective against sleep-disordered breathing. It is very difficult to understand whereas obstructive sleep apnea in women is independently associated with hypertension or if many confounders acting at different stages of the woman lifespan mediate this relation.The cardioprotective effect of physical activity in women of all ages is well known. Women are generally more physically inactive than men. During and after menopause, most women tend to reduce their physical activity levels and together with the reduction in basal metabolic rate, women experience loss of skeletal muscle mass with a negative change in the ratio of fat-to-lean mass.In conclusion, sex differences in the cardiovascular system are because of dissimilarities in gene expression and sex hormones; these result in variations in prevalence and presentation of CVD and associated conditions, such as diabetes, hypertension and vascular and cardiac remodeling.Changes in lifestyle and increase in physical activity could help in prevention of cardiovascular disease in women.

The menopause transition and women's health at midlife: a progress report from the Study of Women's Health Across the Nation (SWAN)

OBJECTIVE

Our initial understanding of the menopause transition (MT) has been framed by clinical samples of women seeking treatment rather than by population-based studies. The Study of Women's Health Across the Nation (SWAN) initiated in 1996 with an overall goal to define the MT, to characterize its biological and psychosocial antecedents and sequelae in an ethnically and racially diverse sample of midlife women.

METHODS

This review summarizes the central findings of SWAN to date that can inform women and their healthcare providers about the impact of the MT and midlife aging on overall health and well-being.

RESULTS

SWAN characterized changes in reproductive axis and menstrual cycle patterns that informed the development of the reproductive aging staging system Staging of Reproductive Aging Workshop+10; MT-related symptoms and mental health (vasomotor symptoms, sleep complaints, psychological symptoms, cognitive performance, and urogenital and sexual health); and physiological systems and functions (cardiovascular and cardiometabolic health, bone health, physical function performance) that are influenced by the MT. SWAN demonstrated substantial interrelations among these changes and significant racial/ethnic differences in the rate and magnitude of change in multiple health indictors in midlife women. The findings point to midlife as a critical stage for adopting healthy behavior and preventive strategies.

CONCLUSIONS

Over the past 23 years, SWAN has advanced our understanding of the impact of the MT and midlife aging on health and well-being in women. SWAN will be instrumental to determine whether MT-related changes during midlife are related to unfavorable health and well-being in early old age.

Relationship between sleep duration and hypertension in northeast China: a cross-sectional study

OBJECTIVES

Previous studies have reported that sleep duration might increase the risk of hypertension. However, the results have been conflicting. We investigated whether sleep duration is independently associated with hypertension. We aimed to assess the relationship between sleep duration and hypertension in a population-based cross-sectional study.

METHODS

In this study we used multistage stratified cluster sampling. A total of 19 407 adults aged 18-79 years were enrolled in the study. The participants were divided into three groups (<7 hours/day, 7-8 hours/day and >8 hours/day) according to self-reported sleep duration. Hypertension was defined as systolic blood pressure ≥140 mm Hg or diastolic blood pressure ≥90 mm Hg or the use of anti-hypertensive medications. Univariate and multivariate logistic regressions were performed to determine the association between hypertension and sleep duration adjusted for sociodemographic, body mass index, and lifestyle covariates.

RESULTS

The overall prevalence of hypertension was 32.6%. Among participants aged 18-44 years, individuals sleeping less than 7 hours per day had a higher risk of hypertension (OR=1.24, 95% CI: 1.05 to 1.46), compared with those who slept 7-8 hours per day. There were no significant associations between sleep duration and hypertension in the total sample, among middle-aged adults (45-59 years) or older adults (60-79 years).

CONCLUSIONS

Our study demonstrates that short sleep duration was significantly associated with hypertension among people aged 18-44 years in northeast China.

Insomnia and hypertension: A systematic review

Insomnia is a prevalent sleep disorder that is associated with a multitude of health consequences. Particularly, insomnia has been associated with cardiovascular disease and its precursors, such as hypertension and blood pressure (BP) non-dipping. The present systematic review aimed to summarize the evidence on the concurrent and prospective associations between insomnia and hypertension and/or BP. Using electronic search engines (PubMed, SCOPUS, PsycINFO), 5,618 articles published from January 1970 to December 2017 were identified, and 64 met the inclusion criteria (26 to 162,121 participants; age range: 18-100; 46.4% male). Insomnia was based on diagnostic or non-diagnostic criteria. Hypertension was based on self-or physician-reports, antihypertensive medication use, and/or measured BP. Findings indicate that when insomnia is frequent, chronic, and/or accompanied with short sleep duration or objective markers of arousal, there is a strong association with hypertension/BP. Based on limited studies, hypertension did not significantly predict future insomnia in middle-aged adults, but did in older adults. Based on a majority of case-control studies, no differences in BP were found between participants with and without insomnia. Further research is needed to identify putative pathophysiological mechanisms underlying the link between insomnia and hypertension. The impact of insomnia therapy on BP should also be further examined in the future.

Snoring and Blood Pressure in Third-Trimester Normotensive Pregnant Women

PURPOSE

To examine the association between snoring, sleep quality, quantity, and blood pressure in third-trimester normotensive pregnant women.

DESIGN

This study was a cross-sectional analysis of two cohorts of healthy pregnant women recruited from a prenatal clinic in a medical center in Northern Taiwan.

METHODS

A total of 322 women reported sociodemographic and health characteristics in a structured interview and wore a wrist actigraph on their nondominant wrist for 7 consecutive days to assess objective sleep patterns. The women's resting blood pressures were measured while seated in the clinic by trained personnel using an electronic sphygmomanometer.

FINDINGS

One hundred thirty-three (41.3%) women reported snoring. Ninety-three women (28.9%) had <6 hr of nighttime sleep, with only 95 (29.5%) women averaging 7 or more hours of nighttime sleep. In the univariate analyses, snoring was positively associated with systolic and diastolic blood pressure as well as mean arterial pressure levels (p < .05). In the multivariate analyses, snoring remained as a significant predictor of higher diastolic blood pressure (β = 2.07, p < .05) and mean arterial pressure levels (β = 2.00, p < .05), after adjustment for age, parity, gestational age, body mass index before pregnancy, and sleep quantity and quality by actigraphy.

CONCLUSIONS

Snoring is a highly prevalent condition experienced by healthy third-trimester pregnant women and is associated with elevated blood pressure.

CLINICAL RELEVANCE

Clinical assessment and screening of snoring are of utmost importance in obstetric nursing practice to potentially prevent or reduce the associated adverse cardiovascular consequences in women during pregnancy.

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.

Altered nocturnal blood pressure profiles in women with insomnia disorder in the menopausal transition

OBJECTIVE

Insomnia disorder is a risk factor for cardiovascular (CV) pathology. It is unknown whether insomnia that develops in the context of the menopausal transition (MT) impacts the CV system. We assessed nocturnal blood pressure (BP) and heart rate (HR) profiles in women with insomnia disorder in the MT.

METHODS

Twelve women meeting DSM-IV criteria for insomnia in the MT (age, mean ± SD: 50.5 ± 3.6 y) and 11 controls (age, mean ± SD: 49.0 ± 3.0 y) had polysomnographic recordings on one or two nights during which beat-to-beat BP and HR were assessed and analyzed hourly from lights-out across the first 6 hours of the night and according to sleep stage. Physiological hot flashes were identified from fluctuations in sternal skin conductance.

RESULTS

Women with insomnia and controls had similar distributions of sleep stages and awakenings/arousals across hours of the night, although insomnia participants tended to have more wakefulness overall. More women in the insomnia group (7 of 12) than in the control group (2 of 11) had at least one physiological hot flash at night (P < 0.05). Both groups showed a drop in BP in the first part of the night; however, systolic and diastolic BP patterns diverged later, remaining low in controls but increasing in insomnia participants 4 to 6 hours after lights-out (P < 0.05). Both groups showed a similar pattern of decline in HR across the night.

CONCLUSIONS

Our findings suggest altered regulatory control of BP during sleep in the MT insomnia. The causes and long-term consequences of this altered nocturnal BP profile remain to be determined.

Sleep problems during the menopausal transition: prevalence, impact, and management challenges

A substantial number of women experience sleep difficulties in the approach to menopause and beyond, with 26% experiencing severe symptoms that impact daytime functioning, qualifying them for a diagnosis of insomnia. Here, we review both self-report and polysomnographic evidence for sleep difficulties in the context of the menopausal transition, considering severity of sleep complaints and links between hot flashes (HFs) and depression with poor sleep. Longitudinal population-based studies show that sleep difficulties are uniquely linked with menopausal stage and changes in follicle-stimulating hormone and estradiol, over and above the effects of age. A major contributor to sleep complaints in the context of the menopausal transition is HFs, and many, although not all, HFs are linked with polysomnographic-defined awakenings, with HF-associated wake time contributing significantly to overall wakefulness after sleep onset. Some sleep complaints may be comorbid with depressive disorders or attributed to sleep-related breathing or movement disorders, which increase in prevalence especially after menopause, and for some women, menopause, age, and environmental/behavioral factors may interact to disrupt sleep. Considering the unique and multifactorial basis for sleep difficulties in women transitioning menopause, we describe clinical assessment approaches and management options, including combination treatments, ranging from cognitive behavioral therapy for insomnia to hormonal and nonhormonal pharmacological options. Emerging studies suggest that the impact of severe insomnia symptoms could extend beyond immediate health care usage and quality of life issues to long-term mental and physical health, if left untreated in midlife women. Appropriate treatment, therefore, has immediate benefit as well as advantages for maintaining optimal health in the postmenopausal years.

Sleep Characteristics and Carotid Atherosclerosis Among Midlife Women

Introduction

Midlife, which encompasses the menopause transition in women, can be a time of disrupted sleep and accelerated atherosclerosis accumulation. Short or poor sleep quality has been associated with cardiovascular disease (CVD) risk; few studies have investigated relations among midlife women. We tested whether shorter actigraphy sleep time or poorer subjective sleep quality was associated with carotid atherosclerosis among midlife women.

Aims and Methods

Two hundred fifty-six peri- and postmenopausal women aged 40-60 years completed 3 days of wrist actigraphy, hot flash monitoring, questionnaires (Pittsburgh Sleep Quality Index [PSQI], Berlin), a blood draw, and carotid ultrasound [intima media thickness (IMT), plaque]. Associations of objective (actigraphy) and subjective (PSQI) sleep with IMT/plaque were tested in regression models (covariates: age, race, education, body mass index, blood pressure, lipids, insulin resistance, medications, snoring, depressive symptoms, sleep hot flashes, and estradiol).

Results

Shorter objective sleep time was associated with higher odds of carotid plaque (for each hour shorter sleep, plaque score ≥ 2, odds ratio (OR) [95% confidence interval, CI] = 1.58 [1.11-2.27], p = .01; plaque score = 1, OR [95% CI] = 0.95 [0.68-1.32], p = .75, vs. no plaque, multivariable). Poorer subjective sleep quality was associated with higher mean IMT [β, b (standard error, SE) = 0.004 (0.002), p = .03], maximal IMT [b (SE) = 0.009 (0.003), p = .005], and plaque [plaque score ≥ 2, OR (95% CI) = 1.23 (1.09-1.40), p = .001; score = 1, OR (95% CI) = 1.06 (0.93-1.21), p = .37, vs. no plaque] in multivariable models. Findings persisted additionally adjusting for sleep hot flashes and estradiol.

Conclusions

Shorter actigraphy-assessed sleep time and poorer subjective sleep quality were associated with increased carotid atherosclerosis among midlife women. Associations persisted adjusting for CVD risk factors, hot flashes, and estradiol.

Longitudinal Study of Insomnia Symptoms Among Women During Perimenopause

OBJECTIVE

To describe the prevalence of insomnia symptoms among women during perimenopause and to examine differences in self-reported insomnia symptoms at different stages of perimenopause over 10 years.

DESIGN

Secondary analysis of self-reported sleep symptoms and clinical variables using 10 years of publicly available data from the Study of Women Across the Nation (SWAN).

SETTING

The data set of women's insomnia symptoms was obtained from publicly available data from the SWAN. The parent study settings included Detroit, Michigan; Northern New Jersey; Los Angeles, California; Boston, Massachusetts; Chicago, Illinois; and Pittsburgh, Pennsylvania.

PARTICIPANTS

Multiethnic midlife women with a mean age of 46 years (N = 3,302) categorized as pre- and perimenopausal at baseline.

METHODS

Dependent variables included self-reported insomnia symptoms: difficulty falling asleep (sleep latency), wake after sleep onset, early morning awakenings, and sleep quality. Descriptive analysis was completed for each 1-year study interval. Repeated measures logistic regression was used to identify whether insomnia symptoms changed over time by stage of perimenopause.

RESULTS

Insomnia symptoms were present in 31% to 42% of perimenopausal women at any 1-year study interval. Insomnia symptoms were more prevalent in the late stage of perimenopause than the early stage (p < .001). The odds of having any insomnia symptoms were 1.3 times greater for women in the late stage of perimenopause than in the early stage (95% confidence interval [1.2, 1.5], p < .001).

CONCLUSION

Insomnia symptoms are prevalent in women transitioning to menopause, and stage of perimenopause may heighten the risk to develop symptoms of insomnia disorder, which is associated with negative cardiometabolic outcomes.

The effects of midday nap duration on the risk of hypertension in a middle-aged and older Chinese population: a preliminary evidence from the Tongji-Dongfeng Cohort Study, China

OBJECTIVE

Evidence from epidemiological studies suggested that shorter and longer duration of nocturnal sleeping may increase the risk of hypertension for older adults. Little is known about the duration of midday nap on the variability of blood pressure among older adults. In this study, we examined whether duration of habitual midday nap is associated with level of blood pressure or the risk of hypertension in a middle-aged and older Chinese population.

METHODS

A total of 27 009 participants (mean age 63.6 years) from Dongfeng-Tongji Cohort Study received baseline examination including physical examination and laboratory tests, and a face-to-face-interview including demographic information, disease history, and lifestyle. Participants were categorized into five groups according to nap duration, such as no napping, less than 30 min, 30∼60 min, 60∼90 min, and at least 90 min. A series of categorical logistic regression models was used to examine the odd ratios of nap duration with hypertension.

RESULTS

The level of SBP and DBP increased significantly with longer duration of habitual midday napping. Nappers with longer nap duration had considerably higher rate of hypertension. The longer duration of napping was related to higher blood pressure level and was associated with a higher risk of hypertension. After adjusting for possible confounders, the longer duration (>60 min) of napping was still associated with hypertension

CONCLUSION

: Our findings showed that the practice of longer afternoon nap is associated with a higher increased risk of hypertension, independent of several covariates. Further prospective researches are needed to examine the midday nap duration for development of hypertension.

A review of evidence for the link between sleep duration and hypertension

There are lines of evidence from experimental sleep deprivation studies, population-based epidemiological studies, and an interventional study that point to the potential efficacy of adequate quality sleep to prevent and treat hypertension. Experimental sleep restriction has been shown to raise blood pressure and heart rate. Insufficient sleep on a chronic basis can raise average 24-hour blood pressure and lead to structural adaptations that entrain the cardiovascular system to operate at an elevated blood pressure equilibrium and increase the risk for hypertension. Disruptions in the timing and duration of sleep could also disrupt circadian rhythmicity and autonomic balance, which can increase the prevalence of the nondipping pattern, disturb diurnal rhythm of cardiac output, and increase blood pressure variability. Short sleep duration has been found to be associated with higher blood pressure and hypertension in both cross-sectional and longitudinal epidemiological studies. The association appears stronger in middle-aged adults and in women. Experimental sleep extension has been shown to significantly reduce blood pressure in individuals with prehypertension or stage 1 hypertension. The observed association between sleep duration and hypertension raises the hypothesis that interventions to extend sleep and improve sleep quality could serve as effective primary, secondary, and tertiary preventive measures for hypertension.