Blood pressure dipping: ethnicity, sleep quality, and sympathetic nervous system activity

Racial and ethnic sleep health disparities in adolescents and risk for type 2 diabetes: a narrative review

INTRODUCTION

Sleep is an essential factor for health and wellbeing in people across the age spectrum; yet many adolescents do not meet the recommended 8-10 h of nightly sleep. Unfortunately, habitually insufficient sleep, along with the metabolic changes of puberty, puts adolescents at increased risk for a host of adverse health outcomes such as obesity and type 2 diabetes (T2D). Furthermore, individuals from historically minoritized racial and ethnic groups (e.g. Hispanic/Latinx, African American/Black) are more likely to experience shorter sleep duration compared to adolescents of White/European origin, placing them at even greater risk for disparities in T2D risk.

METHODS

We conducted a literature review on the role of race and ethnicity in adolescent sleep health and its relation to cardiometabolic outcomes, specifically T2D. We use the minority stress model and the stress and coping theory as guiding theoretical frameworks to examine individual and societal level factors that may contribute to sleep health disparities and their downstream effects on T2D risk.

RESULTS

This review highlights that the unique race-related stressors adolescents from minoritized groups face may play a role in the sleep and T2D connection on a biological, psychological, and social level. However, although there has been advancement in the current research on adolescent racial and ethnic sleep health disparities in relation to T2D, mechanisms underlying these disparities in sleep health need further investigation. Addressing these gaps is crucial for identifying and mitigating sleep health disparities and T2D among racial and ethnic minority youth.

CONCLUSION

We conclude with a discussion of the implications and future research directions of racial and ethnic disparities in sleep health and T2D prevention research. A comprehensive understanding of adolescent sleep health disparities has potential to better inform preventative and educational programs, interventions, and policies that promote sleep health equity and improve cardiometabolic outcomes like T2D.

Sleep timing and the prevalence of hypertension in middle-aged and older populations: the sleep heart health study

OBJECTIVES

Sleep characteristics such as duration, continuity, and irregularity are associated with the risk of hypertension. This study aimed to investigate the association between sleep timing (including bedtime, wake-up time, and sleep midpoint) and the prevalence of hypertension.

METHODS

Participants were selected from the Sleep Heart Health Study (n = 5504). Bedtime and wake-up times were assessed using sleep habit questionnaires. The sleep midpoint was calculated as the halfway point between the bedtime and wake-up time. Restricted cubic splines and logistic regression analyses were performed to explore the association between sleep timing and hypertension.

RESULTS

A significant nonlinear association was observed between bedtime (Poverall<0.001; Pnonlinear<0.001), wake-up time (Poverall=0.024; Pnonlinear=0.076), sleep midpoint (Poverall=0.002; Pnonlinear=0.005), and the prevalence of hypertension after adjusting for potential confounders. Multivariable logistic regression showed that both late (> 12:00AM and 23:01PM to 12:00AM) and early (≤ 22:00PM) bedtimes were associated with an increased risk of hypertension compared to bedtimes between 22:01PM and 23:00PM. In addition, individuals with late (> 7:00AM) and early (≤ 5:00AM) wake-up times had a higher prevalence of hypertension than those with wake-up times ranging between 5:01AM and 6:00AM. Delaying the sleep midpoint (> 3:00AM) was also associated with an increased risk of hypertension. Furthermore, no significant interaction effect was found in the subgroup analyses stratified by age, sex, or apnea-hypopnea index.

CONCLUSIONS

Our findings identified a nonlinear association between sleep timing and hypertension. Individuals with both early and late sleep timing had a high prevalence of hypertension.

Device-estimated sleep metrics do not mediate the relation between race and blood pressure dipping in young black and white women

Short, disturbed, and irregular sleep may contribute to blunted nocturnal blood pressure (BP) dipping, a predictor of cardiovascular disease. Black women (BLW) demonstrate less BP dipping and poorer sleep health than White women (WHW). However, it remains unclear whether device-estimated sleep health metrics mediate the relation between race and BP dipping in young women. We hypothesized that the relation between race and BP dipping would be partly mediated by sleep health metrics of sleep duration, sleep efficiency, and sleep regularity. Participants (20 BLW, 17 WHW) were 18-29 years old, normotensive, nonobese, and without evidence of sleep disorders. Systolic and diastolic BP dipping were derived from 24-h ambulatory BP monitoring. Habitual sleep duration and sleep efficiency were estimated via 14 days of wrist actigraphy. Sleep duration regularity was calculated as the standard deviation (SD) of nightly sleep duration (SDSD). Sleep timing regularity metrics were calculated as the SD of sleep onset and sleep midpoint (SMSD). Mediation analysis tested the mediating effect of each sleep metric on the relation between race and BP dipping. BLW experienced less systolic (P = .02) and diastolic (P = .01) BP dipping. Sleep duration (P = .14) was not different between groups. BLW had lower sleep efficiency (P < .01) and higher SDSD (P = .02), sleep onset SD (P < .01) and SMSD (P = .01). No sleep metrics mediated the relation between race and BP dipping (all indirect effects P > .38). In conclusion, mediation pathways of sleep health metrics do not explain racial differences in nocturnal BP dipping between young BLW and WHW.

Orthostatic hypotension, orthostatic hypertension, and ambulatory blood pressure in patients with chronic kidney disease in CRIC

BACKGROUND

Orthostatic changes in blood pressure (BP), either orthostatic hypotension or orthostatic hypertension (OHTN), are common among patients with chronic kidney disease. Whether they are associated with unique out-of-office BP phenotypes is unknown.

METHODS

CRIC is a prospective, multicenter, observational cohort study of participants with CKD. BP measured at 2 min after standing and ambulatory BP monitoring (ABPM) were obtained on 1386 participants. Orthostatic hypotension was defined as a 20 mmHg drop in SBP or 10 mmHg drop in DBP when changing from seated to standing positions. Systolic and diastolic night-to-day ratio was also calculated. OHTN was defined as a 20 or 10 mmHg rise in SBP or DBP when changing from a seated to a standing position. White-coat effect (WCE) was defined as seated minus daytime ambulatory BP.

RESULTS

Of the 1386 participants (age: 58 ± 10 years, 44% female, 39% black), 68 had orthostatic hypotension and 153 had OHTN. Postural reduction in SBP or DBP was positively associated with greater systolic and diastolic WCE and systolic and diastolic night-to-day ratio. Orthostatic hypotension was positively associated with diastolic WCE (β = 3 [0.2, 5.9]). Diastolic OHTN was negatively associated with systolic WCE (β = -4 [-7.2, -0.5]) and diastolic WCE (β = -6 [-8.1, -4.2]).

CONCLUSION

Postural change in BP was associated with WCE and night-to-day-ratio. Orthostatic hypotension was positively associated with WCE and OHTN was negatively associated with WCE. These findings strengthen observations that postural changes in BP may associate with distinct BP patterns throughout the day. These observations are informative for subsequent research tailoring orthostatic hypotension and OHTN treatment to specific BP phenotypes.

Obesity in Hypertensive Patients Is Characterized by a Dawn Phenomenon in Systolic Blood Pressure Values and Variability

One of the causes of hypertension is excess weight gain, which can also affect the course of this disease. Both the diagnosis and management of hypertension commonly use ambulatory blood pressure monitoring; the results of which correlate more strongly with cardiovascular diseases and cardiovascular death than office blood pressure monitoring. We evaluated blood pressure values and their variability from hour to hour to see if and when they differed between hypertensive patients with and without obesity. The study included 1345 patients who underwent 24 h ambulatory blood pressure monitoring and then were divided into groups according to body mass index and waist circumference. The obtained data were analyzed according to the subjects' wake-up time, and short-term blood pressure variability parameters were calculated as the mean of the absolute values of the differences between consecutive measurements. The systolic blood pressure in obese subjects was significantly higher between 1 and 5 h before waking than in normal-weighted individuals. In turn, the variability in systolic and diastolic blood pressure was higher with increasing body mass index. The difference in systolic blood pressure values and blood pressure variability was most prominent in the last 5 h of sleep in obese patients.

Classification of blood pressure during sleep impacts designation of nocturnal nondipping

The identification of nocturnal nondipping blood pressure (< 10% drop in mean systolic blood pressure from awake to sleep periods), as captured by ambulatory blood pressure monitoring, is a valuable element of risk prediction for cardiovascular disease, independent of daytime or clinic blood pressure measurements. However, capturing measurements, including determination of wake/sleep periods, is challenging. Accordingly, we sought to evaluate the impact of different definitions and algorithms for defining sleep onset on the classification of nocturnal nondipping. Using approaches based upon participant self-reports, applied definition of a common sleep period (12 am -6 am), manual actigraphy, and automated actigraphy we identified changes to the classification of nocturnal nondipping, and conducted a secondary analysis on the potential impact of an ambulatory blood pressure monitor on sleep. Among 61 participants in the Eastern Caribbean Health Outcomes Research Network hypertension study with complete ambulatory blood pressure monitor and sleep data, the concordance for nocturnal nondipping across methods was 0.54 by Fleiss' Kappa (depending on the method, 36 to 51 participants classified as having nocturnal nondipping). Sleep quality for participants with dipping versus nondipping was significantly different for total sleep length when wearing the ambulatory blood pressure monitor (shorter sleep duration) versus not (longer sleep duration), although there were no differences in sleep efficiency or disturbances. These findings indicate that consideration of sleep time measurements is critical for interpreting ambulatory blood pressure. As technology advances to detect blood pressure and sleep patterns, further investigation is needed to determine which method should be used for diagnosis, treatment, and future cardiovascular risk.

Racial-ethnic diversity in ambulatory blood pressure monitoring in children with chronic kidney disease

BACKGROUND

Black adults with chronic kidney disease (CKD) have higher rates of hypertension as compared to White adults with CKD. Little is known of how race and ethnicity associate with the prevalence of hypertension in pediatric CKD patients. The aim was to compare ambulatory blood pressure monitoring (ABPM) results for patients with CKD enrolled in the Chronic Kidney Disease in Children (CKiD) study across racial-ethnic groups.

METHODS

Patients from the CKiD study who identified as non-Hispanic White, non-Hispanic Black, or Hispanic were included to analyze differences in ABPM results across these racial-ethnic groups. The outcomes were fitted using 3 progressively adjusted models.

RESULTS

This study included 501 CKiD participants with at least one successful ABPM study. Compared to White participants, Black participants had 4.2 mmHg higher mean sleep systolic blood pressure and 2.7 mmHg higher mean sleep diastolic blood pressure (p = 0.001 and p = 0.004, respectively). Additionally, Black participants had higher odds of abnormal wake systolic load (OR 1.88, 1.21-2.91, p = 0.005), wake diastolic load (OR 1.68, 1.03-2.73, p = 0.04), sleep systolic load (OR 2.19, 1.36-3.5, p = 0.001), sleep diastolic load (OR 2.01, 1.28-3.15, p = 0.002), systolic non-dipping (OR 2.02, 1.31-3.10, p = 0.001), and diastolic non-dipping (OR 2.69, 1.60-4.51, p < 0.001). Compared to White participants, Hispanic participants demonstrated only a lower sleep diastolic load (OR 0.54, 0.31-0.95, p = 0.03).

CONCLUSIONS

Black children with CKD have higher absolute nocturnal blood pressures and higher rates of abnormal dipping. Further studies are needed to determine the etiology of these differences and the clinical implications of racial-ethnic differences in ABPM outcomes within the pediatric CKD population. A higher resolution version of the Graphical abstract is available as Supplementary information.

Racial differences in sympathetic nervous system indicators: Implications and challenges for research

Growing evidence indicates the presence of racial differences in sympathetic nervous system (SNS) functioning, yet the nature of these differences is unclear and appears to vary across different indices of SNS activity. Moreover, racial differences among commonly used indices of SNS activity are under-investigated. This systematic review examines racial differences among widely used resting SNS indices, such as electrodermal activity (EDA), pre-ejection period (PEP), and salivary alpha-amylase (sAA). Our review reveals that Black participants have consistently been found to display lower resting EDA compared to White participants. The few studies that have investigated or reported racial differences in PEP and sAA yield mixed findings about whether racial differences exist. We discuss potential reasons for racial differences in SNS activity, such as index-specific factors, lab confounds, psychosocial environmental factors, and their interactions. We outline a framework characterizing possible contributors to racial differences in SNS functioning. Lastly, we highlight the implications of several definitional, analytic, and interpretive issues concerning the treatment of group differences in psychophysiological activity and provide future recommendations.

Disrupted Circadian Rhythm of Epinephrine in Males With Youth-Onset Type 2 Diabetes

Context

Blood pressure and plasma catecholamines normally decline during sleep and rapidly increase in early morning. This is blunted in adults with type 2 diabetes (T2D).

Objective

We hypothesize that increased sympatho-adrenal activity during sleep differentiates youth with T2D from nondiabetic obese youth and lean youth.

Methods

Fasting spot morning and 24-hour urines were collected in obese adolescents with and without T2D, and normal-weight controls. Fractionated free urine catecholamines (epinephrine, norepinephrine, and dopamine) were measured, and the ratio of fasting spot morning to 24-hour catecholamines was calculated.

Results

Urinary 24-hour catecholamine levels were comparable across the 3 groups. Fasting morning epinephrine and the ratio of fasting morning/24-hour epinephrine were higher in youth with T2D (P = 0.004 and P = 0.035, respectively). In males, the ratio of fasting morning/24-hour epinephrine was also higher in youth with T2D (P = 0.005). In females, fasting morning norepinephrine and the ratio of fasting morning/24-hour dopamine were lower in obese youth with and without T2D (P = 0.013 and P = 0.005, respectively) compared with lean youth. Systolic blood pressure was higher in diabetic participants than other groups; males trended higher than females.

Conclusion

Circadian rhythm in catecholamines is disrupted in youth-onset T2D, with a blunted overnight fall in urinary epinephrine in males. Conversely, fasting morning norepinephrine and dopamine levels were lower in obese females with or without T2D. Higher nocturnal catecholamines in males with T2D might associate with, or predispose to, hypertension and cardiovascular complications. Lower catecholamine excretion in females with obesity might serve an adaptive, protective role.

Sleep characteristics associated with nocturnal blood pressure nondipping in healthy individuals: a systematic review

OBJECTIVE

The current literature investigating nocturnal blood pressure (BP) nondipping has largely focused on clinical populations, however, conditions such as hypertension, obstructive sleep apnoea and insomnia are recognized confounding factors for BP dipping. The exact mechanisms responsible for BP nondipping remain unclear, therefore, there is a need to investigate BP nondipping in healthy individuals to better understand the underlying mechanisms. This review identifies sleep characteristics that may contribute to BP nondipping in healthy individuals. It is anticipated that an understanding of the sleep characteristics that contribute to BP nondipping may inform future sleep-related behavioral interventions to ultimately reducing the burden of cardiovascular disease.

METHODS

The PubMed, Scopus and Web of Science databases were searched for relevant, English language, peer-reviewed publications (from inception to March 2022). The search identified 550 studies. After duplicates were removed, the titles and abstracts of the remaining 306 studies were screened. Of these, 250 studies were excluded leaving 56 studies to test for eligibility. Thirty-nine studies were excluded such that 17 studies fully met the inclusion criteria for the review.

RESULTS

Findings from this review indicate that short sleep duration, more sleep fragmentation, less sleep depth and increased variability in sleep timing may be associated with BP nondipping in healthy individuals.

CONCLUSION

While there is no evidence-based approach for the treatment of nocturnal BP nondipping, it seems promising that addressing one's sleep health may be an important starting point to reduce the prevalence of BP nondipping and perhaps the progression to cardiovascular disease.

Prevalence and determinants of hypertension among urban slum dwellers in Bangladesh

Background

In low- and middle- income countries such as Bangladesh, urban slum dwellers are particualry vulnerable to hypertension due to inadequate facilities for screening and management, as well as inadequate health literacy among them. However, there is scarcity of evidence on hypertension among the urban slum dwellers in Bangladesh. The present study aimed to determine the prevalence and factors associated with hypertension among urban slum dwellers in Bangladesh.

Methods

Data were collected as part of a large-scale cross-sectional survey conducted by Building Resources Across Communities (BRAC) between October 2015 and January 2016. The present analysis was performed among 1155 urban slum dwellers aged 35 years or above. A structured questionnaire was adminstered to collect data electronically and blood pressure measurements were taken using standardised procedures. Binary logistic regression with generalized estimating equation modelling was performed to estimate the factors associated with hypertension.

Results

The prevalence of hypertension was 28.3% among urban slum dwellers aged 35 years and above. In adjusted analysis, urban slum dwellers aged 45–54 years (AOR: 1.64, 95% CI: 1.17–2.28), 55–64 years (AOR: 2.47, 95% CI: 1.73–3.53) and ≥ 65 years (AOR: 2.34, 95% CI: 1.47–3.72), from wealthier households (AOR: 1.94, 95% CI: 1.18–3.20), sleeping < 7 h per day (AOR: 1.87, 95% CI: 1.39–2.51), who were overweight (AOR: 1.53, 95% CI: 1.09–2.14) or obese (AOR: 2.34, 95% CI: 1.71–3.20), and having self-reported diabetes (AOR: 3.08, 95% CI: 1.88–5.04) had an increased risk of hypertension. Moreover, 51.0% of the participants were taking anti-hypertensive medications and 26.4% of them had their hypertension in control.

Conclusions

The findings highlight a high burden of hypertension and poor management of it among the slum dwellers in Bangladesh requiring a novel approach to improve care. It is integral to effectively implement the available national non-communicable disease (NCD) control guidelines and redesign the current urban primary health care system to have better coordination.

The effect of acute alcohol ingestion on systemic hemodynamics and sleep architecture in young, healthy men

Objective Heightened nocturnal blood pressure (BP) may be attributed to the disruption of sleep, a condition worsened by alcohol ingestion. This study investigated the effects of acute alcohol ingestion on hemodynamics and sleep architecture in a young, healthy cohort of male. METHODS: Subjects (n = 17) underwent acute alcohol ingestion reaching a breath alcohol content of 0.08. Each subject endured a battery of hemodynamic tests and had their sleep architecture and nocturnal blood pressure monitored pre- and post-ingestion. Results: Systolic blood pressure (SBP) increased both 30 minutes and 12 hours after alcohol. Ambulatory nocturnal SBP significantly increased after alcohol compared to baseline measures. Minutes of total, rapid eye movement, and light sleep all increased after alcohol ingestion, while a decrease was observed for sleep latency. Conclusions: An acute bout of heavy alcohol consumption may attenuate nocturnal BP dipping that, in turn, may hasten the progression of hypertension-related cardiovascular disease.

Association Between Bedtime at Night and Systolic Blood Pressure in Adults in NHANES

Objectives: This study aimed to explore the association between bedtime at night and systolic blood pressure (SBP) in adults.

Methods: We conducted a cross-sectional study composed of 7,642 individuals from the National Health and Nutrition Examination Survey (NHANES). Bedtime was defined as the response to the question: “What time do you usually fall asleep on weekdays or workdays?” SBP was taken using the average of all measured values. Multiple linear regression analyses were done to explore the relationship between bedtime and SBP.

Results: The bedtime was changed from categorical variable to continuous variable for data analysis, and a significantly negative association was identified between bedtime and SBP (β, −0.23 [95% CI, −0.43, −0.02]). With the delay of bedtime, the SBP showed a gradual decrease trend, and it was dropped to the lowest at 0:00. After 0:00, the SBP was gradually increased with the delay of sleep time. The stratified analyses showed that in the female group, with the delay of bedtime, the range of SBP was decreased more obviously at 0:00. In the 18–45 year group, bedtime had little effect on SBP. Among ≥45 years old group, this trend was still the same. In the black group, an obvious downward trend was found at 22:00.

Conclusion: With the delay of bedtime, the SBP had shown a gradual decrease trend, and it was dropped to the lowest at 0:00. After 0:00, the SBP was gradually increased with the delay of sleep time. Bedtime and SBP showed a U-shaped relationship.

Stress, coping, resilience, and sleep during the COVID-19 pandemic: A representative survey study of US adults

INTRODUCTION

The COVID-19 pandemic is a global health emergency resulting in widespread death and substantial disruption to daily life. Previous research has shown that novel disease outbreaks are associated with high stress levels and sleep impairments that lead to neuropsychiatric consequences. Therefore, it is vital to study both stress and protective factors such as coping and resilience that may hinder or help sleep quality during the COVID-19 pandemic. Further, as gender disparities exist in sleep quality, it is important to understand the relationship between pandemic-related stress, coping strategies, resilience, and sleep in bothgenders during the COVID-19 pandemic.

METHODS

Our study examined how gender, stress, coping, and resilience were associated with sleep cross-sectionally during the COVID-19 pandemic in a representative sample of US adults (N = 393).

RESULTS

Consistent with many recent studies, we found that worsened sleep quality in women compared to men persisted during the COVID-19 pandemic. Interestingly, pandemic-related stress was not significantly associated with sleep quality, but pandemicrelated coping was associated with sleep independent of robust controls and trait resilience.

CONCLUSIONS

Greater primary control engagement coping was associated with better sleep quality, while involuntary engagement coping was associated with poor sleep quality. Future research should extend the findings with actigraphy and explore ways to enhance beneficial coping and sleep health during pandemics.

Urinary Stress Hormones, Hypertension, and Cardiovascular Events: The Multi-Ethnic Study of Atherosclerosis

[Figure: see text].

Actigraphy-Derived Sleep Efficiency Is Associated With Endothelial Function in Men and Women With Untreated Hypertension

BACKGROUND

Poor sleep quality is increasingly recognized as an important and potentially modifiable risk factor for cardiovascular disease (CVD). Impaired endothelial function may be 1 mechanism underlying the association between poor sleep and CVD risk. The present study examined the relationship between objective measures of sleep quality and endothelial function in a sample of untreated hypertensive adults.

METHODS

Participants were 127 men (N = 74) and women (N = 53), including 55 African Americans and 72 White Americans, aged 40-60 years (mean age, 45.3 ± 8.5 years), with untreated hypertension (systolic blood pressure 130-159 mm Hg and/or diastolic blood pressure 85-99 mm Hg). Noninvasive brachial artery flow-mediated dilation (FMD) was assessed by ultrasound. Sleep parameters, including sleep efficiency (SE), total sleep time (TST), and subjective sleep quality, were assessed over 7 consecutive days by wrist actigraphy.

RESULTS

Participants averaged 7.76 ± 1 hours in bed, with an average SE of 78 ± 9%, and TST of 6 ± 1 hours. Brachial FMD averaged 3.5 ± 3.1%. In multivariate analyses controlling for sex, race, body mass index, clinic blood pressure, income, smoking, alcohol use, and baseline arterial diameter, SE was positively associated with FMD (β = 0.28, P = 0.012). Subjective sleep quality (β = -0.04, P = 0.63) and TST (β = -0.11, P = 0.25) were unrelated to FMD.

CONCLUSIONS

Poor sleep as indicated by low SE was associated with impaired FMD. These findings for SE are consistent with previous observations of other measures implicating poor sleep as a CVD risk factor. Interventions that improve sleep may also help lower CVD risk.

Effect of Sleep Disturbances on Blood Pressure

This review summarizes recent literature addressing the association of short sleep duration, shift work, and obstructive sleep apnea with hypertension risk, blood pressure (BP) levels, and 24-hour ambulatory BP. Observational studies demonstrate that subjectively assessed short sleep increases hypertension risk, though conflicting results are observed in studies of objectively assessed short sleep. Intervention studies demonstrate that mild and severe sleep restriction are associated with higher BP. Rotating and night shift work are associated with hypertension as shift work may exacerbate the detrimental impact of short sleep on BP. Further, studies demonstrate that shift work may increase nighttime BP and reduce BP control in patients with hypertension. Finally, moderate to severe obstructive sleep apnea is associated with hypertension, particularly resistant hypertension. Obstructive sleep apnea is also associated with abnormal 24-hour ambulatory BP profiles, including higher daytime and nighttime BP, nondipping BP, and a higher morning surge. Continuous positive airway pressure treatment may lower BP and improve BP dipping. In conclusion, efforts should be made to educate patients and health care providers about the importance of identifying and treating sleep disturbances for hypertension prevention and management. Empirically supported sleep health interventions represent a critical next step to advance this research area and establish causality.

Identifying patterns of diurnal blood pressure variation among ELSA-Brasil participants

Ambulatory blood pressure monitoring (ABPM) is the gold standard method for the diagnosis of hypertension. ABPM provides a set of repeated measurements for blood pressure (BP), usually over 24 h. Traditional approaches characterize diurnal BP variation by single ABPM parameters such as average and standard deviation, regardless of the temporal nature of the data. In this way, information about the pattern of diurnal BP variation and relationship between parameters is lost. The objective of this study was to identify and characterize daily BP patterns considering the set of repeated measures from 24-h ABPM. A total of 859 adult participants of the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil) performed a 24-h ABPM record. Hypertension, sex, age, race/color, education, marital status, smoking, alcohol, physical activity, and BMI were the covariables analyzed. Techniques for longitudinal clustering, multinomial models, and models with mixed effects were used. Three daily BP patterns were identified. Daily BP patterns with high BP presented higher standard deviation and morning surge and lower nocturnal dipping. They showed greater systolic BP variability and faster rise than fall in diastolic BP during sleep. Hypertensive, "pardos," and men had greater odds to present these patterns. Daily BP patterns with high BP presented the worst profile concerning ABPM parameters associated with cardiovascular risk. The daily BP patterns identified contribute to the characterization of diurnal BP variation.

Mild sleep restriction increases 24-hour ambulatory blood pressure in premenopausal women with no indication of mediation by psychological effects

BACKGROUND

Studies assessing the impact of sleep restriction (SR) on blood pressure (BP) are limited by short study length, extreme SR (<4 hours a night), and lack of attention to psychological distress as a possible mediator.

METHODS

A community-based cohort was assembled with 237 women (age 34.1 ± 13.5 years; body mass index 25.4 ± 5.4 kg/m²), and a randomized, crossover, intervention study was conducted in 41 women (24 completed: age 30.2 ± 6.5 years; body mass index 24.3 ± 2.8 kg/m²) to determine the causal effect of SR on BP. Sleep was maintained as usual (HS) or reduced by 1.5 hours a night (SR) for 6 weeks. In the cohort, associations between sleep and psychosocial factors were evaluated using multivariable models adjusted for demographic and clinical confounders. In the intervention study, in-office BP was measured weekly; ambulatory BP was measured at end point. Psychological factors were assessed at baseline and end point. Mixed-model analyses with total sleep time (TST, main predictor), week and fraction of time spent in physical activity (covariates), and subject (random effect) were performed.

RESULTS

Among the community cohort, higher perceived stress, stressful events and distress, and lower resilience were associated with shorter sleep, worse sleep quality, and greater insomnia symptoms (P < .05). In the intervention, systolic BP increased as TST decreased (TST × week interaction, [coefficient ± standard error] -0.0097 ± 0.0046, P = .036). Wake ambulatory diastolic blood pressure (-0.059 ± 0.022, P = .021) and mean arterial pressure (-0.067 ± 0.023, P = .018) were higher after SR versus HS. Psychological distress variables were not affected by TST and did not mediate the effects of SR on BP.

CONCLUSIONS

These results suggest that SR influences CVD risk in women via mechanisms independent of psychological stressors.

The Night Effect of Anger: Relationship with Nocturnal Blood Pressure Dipping

INTRODUCTION

The circadian pattern of blood pressure is characterized by a physiological drop occurring after sleep onset. The alteration of this phenomenon (non-dipping, extreme dipping, or reverse dipping) is associated with an increased cardiovascular risk. Besides altered autonomic and endocrine circadian rhythms, psychological aspects seem to play a role in this modification. However, the few studies that have analyzed the influence of psychological dimensions on the dipping phenomenon have reported inconsistent results. This study aimed to examine the relationship between anger expression and blood pressure (BP) dipping.

METHODS

We obtained 24 h ambulatory BP measurements from 151 participants and used them to define three groups according to their dipping status: Dippers (N = 65), Non-Dippers (N = 42), and Extreme Dippers (N = 44). Sociodemographic and anamnestic information was collected, and the State-Trait Anger Expression Inventory was used to assess anger.

RESULTS

Analysis of variance evidenced significant higher scores for Trait Anger Temperament and Anger Expression in Extreme Dippers than in both Dippers and Non-Dippers. However, after controlling for confounding variables, there was no significant relationship with trait anger, and only the result concerning the suppression of anger was confirmed.

CONCLUSIONS

These findings suggest that the analysis of some psychological factors, such as anger, could be necessary to better understand differences in nocturnal BP alterations. Trait anger and suppression of anger may contribute to the description and classification of patients who exhibit a maladaptive dipping phenomenon. However, modifiable (i.e., cigarette consumption) and unmodifiable (i.e., age) risk factors appear to mediate this relationship. Although further studies are necessary to explore this association, these results highlight that some aspects of anger can represent risk factors or markers of maladaptive modulation of the dipping phenomenon.

Circadian hemodynamics in men and women with high blood pressure: dipper vs. nondipper and racial differences

OBJECTIVE

The 'nondipping' pattern of circadian blood pressure (BP) variation is an established independent predictor of adverse cardiovascular outcomes. Although this phenomenon has been widely studied, its underlying circadian hemodynamics of cardiac output and systemic vascular resistance (SVR) have not been well characterized. We evaluated the hypothesis that BP nondipping would be associated with a blunted night-time reduction in SVR in a biracial sample of 140 (63 African-American and 77 white) men and women with elevated clinic BP (130-159/85-99 mmHg).

METHODS AND RESULTS

Twenty-four-hour ambulatory hemodynamics were assessed using standard ambulatory BP monitoring coupled with synchronized ambulatory impedance cardiography. Using the criterion of less than 10% dip in SBP, there were 51 nondippers (SBP dip = 7.3 ± 2.6%) and 89 dippers (SBP dip = 15.5 ± 3.4%). There was minimal change in cardiac output from daytime to night-time in both dippers and nondippers. However, SVR decreased from daytime to night-time, but nondippers compared with dippers exhibited a significantly attenuated decrease in SVR from daytime to night-time (7.8 vs. 16.1%, P < 0.001). Relative to their white counterparts, African-Americans also exhibited blunted SBP dipping (10.9 vs. 14.6%, P < 0.001) as well as an attenuated decrease in SVR (10.8 vs. 15.6%, P < 0.001).

CONCLUSION

Overall, these findings indicate that blunted night-time BP dipping is associated with impairment of the systemic vasodilation that is characteristic of the night-time sleep period and is especially prominent among African-Americans. In the context of high BP, these findings suggest that nondipping may be a manifestation, or marker, of more advanced vascular disease.

Sleep Duration and Blood Pressure: Recent Advances and Future Directions

PURPOSE OF REVIEW

This review discusses the recent literature on subjectively and objectively assessed sleep duration in relation to hypertension risk and out-of-clinic blood pressure (BP) measures and highlights critical areas for future research.

RECENT FINDINGS

Sleep duration, particularly short sleep, may influence BP through disturbed autonomic balance, hormonal imbalances, increased adiposity and metabolic dysfunction, and disrupted circadian rhythms. Observational studies indicate that short and long sleep are associated with hypertension risk, reduced nocturnal dipping, and elevated morning BP, but evidence is stronger for short sleep. Experimental sleep restriction increases BP, while sleep extension may lower BP in prehypertensive individuals. Women and racial/ethnic minorities are more prone to the detrimental effects of short sleep on BP. Additional studies are warranted to clarify the association of objectively assessed sleep with BP level and diurnal pattern and to determine the sex- and race-specific effects of sleep restriction and extension on BP.

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.

The Effects of Ambulatory Blood Pressure Monitoring on Sleep Quality in Men and Women With Hypertension: Dipper vs. Nondipper and Race Differences

BACKGROUND

The nondipping circadian blood pressure (BP) profile is associated with both poor sleep quality and increased cardiovascular risk. The present study aimed to clarify the potential confounding effects of 24-hour ambulatory blood pressure monitoring (ABPM) used to characterize the circadian BP profile by assessing its impact on sleep quality.

METHODS

Participants were 121 middle-aged men and women with untreated hypertension (age = 46 ± 8 years; 43% women; 45% African-American). Subjective sleep quality was assessed using the Pittsburgh Sleep Quality Index. Wrist actigraphy was used to measure sleep quality objectively as sleep efficiency (SE) and total sleep time (TST) on 7 consecutive non-ABPM days (baseline) and 3 subsequent 24-hour ABPM days.

RESULTS

Average ambulatory BP was 137.2 ± 10.8/84.3 ± 8.5 mm Hg during the day and 119.6 ± 12.4/69.5 ± 9.8 mm Hg at night. Using the criterion of <10% dip in systolic BP (SBP) to define nondippers, there were 40 nondippers (SBP dip = 7.3 ± 2.6%) and 81 dippers (SBP dip = 15.5 ± 3.4%). There was no effect of time on SE or TST over non-ABPM and ABPM days, suggesting that ABPM does not adversely affect sleep quality. Sleep quality was generally poorer (lower SE) in nondippers compared with dippers (P = 0.033), but differences were independent of whether or not participants were undergoing 24-hour ABPM. African-American race (P = 0.002) was also associated with lower SE.

CONCLUSION

Sleep quality generally appears to be poor in men and women with untreated hypertension and especially among African-Americans. Importantly, for both dippers and nondippers, we found no evidence that ABPM had an adverse effect on sleep quality.

The consistency of circadian blood pressure and heart rate patterns over three months in women employed in sedentary office jobs

OBJECTIVES

The purpose of this study was to evaluate the consistency of the circadian patterns of blood pressure (BP) and heart rate (HR) variation over a three-month time frame in women employed outside the home.

METHODS

The subjects were 157 healthy women of varying ethnicity (age = 38.2 ± 8.9) who all worked in similar positions at two major medical centers in New York City. Each wore an ambulatory BP monitor during the course of three mid-week work days approximately one month apart. Hourly BPs and HRs were calculated from 9 am to 6 am the following morning and compared among the three days using anova and t tests.

RESULTS

The results indicate that there were virtually no differences in the mean hourly levels of any parameter during the waking period across the three days of assessment. However, mean hourly levels of systolic BP significantly declined from 12 pm to 4 am (P < .04, P = .001, P < .001, P = .001, P = .009, respectively) on the third assessment day compared to the first.

CONCLUSIONS

Because BP and HR respond to environmental demands in an allostatic fashion, the consistency in the waking patterns of BP and HR variation suggest that the patterns of demands on a workday are reasonably stable in this sample of women. The decline in systolic pressures from 12 pm to 4 am over the three assessments may indicate an improving ability to sleep with the monitor over time.

Morning Blood Pressure Surge Relates to Autonomic Neural Activity in Young Non-Dipping Adults: The African-PREDICT Study

BACKGROUND

It is well established that an exaggerated morning blood pressure surge (MBPS) is associated with an increased risk for cardiovascular disease development in hypertensive individuals. However, in non-dipping individuals, a lower surge was reportedly associated with increased cardiovascular risk. Sympathetic nervous system activity is involved in 24-hour blood pressure fluctuations, including night-time dipping and the MBPS. To better understand this interaction, we investigated associations of MBPS with heart-rate variability and baroreceptor sensitivity in young healthy dippers and non-dippers.

METHODS

We included black and white men and women (n=827), aged 20-30 years and determined the MBPS using two formulas: the sleep-trough and dynamic morning surge. For autonomic function we determined baroreceptor sensitivity and heart-rate variability.

RESULTS

The majority of non-dippers in this population were black (70.4%), presenting lower sleep-trough and dynamic morning surge (all p<0.001). Heart-rate variability was comparable between dippers and non-dippers, whereas baroreceptor sensitivity was higher in non-dippers (p=0.021). Despite a suppressed MBPS profile in non-dippers, we found both sleep-trough (β=-0.25; p=0.039) and dynamic morning surge (β=-0.14; p=0.047) to be inversely and independently associated with 24-hour heart-rate variability (total power). These results were absent in dippers.

CONCLUSIONS

In conclusion, we found a higher night-time blood pressure coupled with lower MBPS in young healthy non-dippers. Furthermore, this lower MBPS was independently and negatively associated with autonomic neural activity, suggesting increased autonomic function involvement in MBPS suppression of non-dippers. The predictive value of suppressed nocturnal dipping pattern should be investigated while taking autonomic neural activity into account.

Disparities in Hypertension Among African-Americans: Implications of Insufficient Sleep

PURPOSE OF REVIEW

Sleep deficiency has been proposed as a potential contributor to racial disparities in cardiovascular health. We present contemporary evidence on the unequal burden of insufficient sleep in Blacks/African-Americans and the repercussions for disparate risk of hypertension.

RECENT FINDINGS

The prevalence of insufficient sleep is high and rising and has been recognized as an important cardiovascular risk factor. Presumably due to a constellation of environmental, psychosocial, and individual determinants, these risks appear exacerbated in Blacks/African-Americans, who are more likely to experience short sleep than other ethnic/racial groups. Population-based data suggest that the risk of hypertension associated with sleep deficiency is greater in those of African ancestry. However, there is a paucity of experimental evidence linking short sleep duration to blood pressure levels in African-Americans. Blacks/African-Americans may be more vulnerable to sleep deficiency and to its hypertensive effects. Future research is needed to unequivocally establish causality and determine the mechanism underlying the postulated racial inequalities in sleep adequacy and consequent cardiovascular risk.

Personality and sleep quality: Evidence from four prospective studies

OBJECTIVE

The present study examined the longitudinal association between personality traits and sleep quality in 4 samples of middle-aged and older adults.

METHOD

Participants (N > 22,000) were adults aged 30 to 107 years old from the Wisconsin Longitudinal Study (WLS), the Midlife in the United States Study (MIDUS), the Health and Retirement Study (HRS), and the Midlife in Japan Study (MIDJA). Personality and sleep quality were assessed at baseline and again 4 to 10 years later.

RESULTS

Scoring lower on neuroticism and higher on extraversion was associated with better sleep quality at baseline and over time, with effect sizes larger than those of demographic factors. Low conscientiousness was associated with a worsening of sleep quality over time. Openness and agreeableness were unrelated to sleep quality. Poor sleep quality at baseline was associated with steeper declines in extraversion, agreeableness, and conscientiousness and a smaller decrease in neuroticism over time.

CONCLUSION

Replicable findings across samples support longitudinal associations between personality and sleep quality. This study identified specific personality traits that are associated with poor and worsening sleep quality, and substantiated previous findings that poor sleep quality is associated with detrimental personality trajectories. (PsycINFO Database Record

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.

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.

A Review of the Literature Regarding Sleep and Cardiometabolic Disease in African Descent Populations

In the twenty-first century, African descent populations on both the continent of Africa and throughout the world are experiencing a high rate of both sleep disturbances and cardiometabolic diseases. The most common sleep disturbances are reduced sleep duration, insomnia, disordered circadian rhythm, and obstructive sleep apnea. Cardiometabolic diseases include hypertension, coronary artery disease, diabetes, hyperlipidemia, and the metabolic syndrome. This review seeks to call attention to new insights regarding the impact of sleep disturbance on cardiometabolic risk factors and outcomes and then apply these concepts to African descent populations, a relatively understudied population. Initial data suggest disparities in sleep quality may have an important role in current and emerging patterns of cardiometabolic disease for African descent populations both in the United States and abroad.

CLINICALTRIALSGOV IDENTIFIER

Not applicable.

Repetitive exposure to shortened sleep leads to blunted sleep-associated blood pressure dipping

BACKGROUND

Blood pressure (BP) dips at night during sleep in healthy individuals but in disturbed sleep, dipping is blunted. However, the impact of chronic insufficient sleep duration, with limited intermittent recovery sleep, on BP dipping is not known. The objective of this study was to examine, in a controlled experimental model, the influence of chronic sleep restriction on BP patterns at night and during the day.

METHOD

In a highly controlled 22-day in-hospital protocol, 45 healthy participants (age 32 ± 2 years; BMI 24 ± 1 kg/m; 22 men and 23 women) were randomly assigned to one of two conditions: repeated sleep restriction (4 h of sleep/night from 0300 to 0700 h for three nights followed by recovery sleep of 8 h, repeated four times in succession) or a sleep control group (8 h/night from 2300 to 0700 h).

RESULTS

Beat-to-beat BP and polysomnography were recorded and revealed that sleep-associated DBP dipping was significantly blunted during all four blocks of sleep restriction (P = 0.002). Further, DBP was significantly increased for the whole day during the first, second, and fourth block of sleep restriction (all P < 0.01), and SBP was significantly increased for the whole day during the first block of sleep restriction.

CONCLUSION

Repeated exposure to significantly shortened sleep blunts sleep-associated BP dipping, despite intermittent catch-up sleep. Individuals frequently experiencing insufficient sleep may be at increased risk for hypertension due to repetitive blunting of sleep-associated BP dipping, and resultant elevations in average circadian BP.

Racial differences in nocturnal dipping status in diabetic kidney disease: Results from the STOP-DKD (Simultaneous Risk Factor Control Using Telehealth to Slow Progression of Diabetic Kidney Disease) study

While racial variation in ambulatory blood pressure (BP) is known, patterns of diurnal dipping in the context of diabetic kidney disease have not been well defined. The authors sought to determine the association of race with nocturnal dipping status among participants with diabetic kidney disease enrolled in the STOP-DKD (Simultaneous Risk Factor Control Using Telehealth to Slow Progression of Diabetic Kidney Disease) trial. The primary outcome was nocturnal dipping-percent decrease in average systolic BP from wake to sleep-with categories defined as reverse dippers (decrease <0%), nondippers (0%-<10%), and dippers (≥10%). Twenty-four-hour ambulatory BP monitoring was completed by 108 participants (54% were nondippers, 24% were dippers, and 22% were reverse dippers). In adjusted models, the common odds of reverse dippers vs nondippers/dippers and reverse dippers/nondippers vs dippers was 2.6 (95% confidence interval, 1.2-5.8) times higher in blacks than in whites. Without ambulatory BP monitoring data, interventions that target BP in black patients may be unable to improve outcomes in this high-risk group.

Habitual sleep as a contributor to racial differences in cardiometabolic risk

Insufficient and disrupted sleep is linked with cardiovascular and metabolic dysregulation and morbidity. The current study examines the degree to which differences in sleep between black/African American (AA) and white/European American (EA) adults explain racial differences in cardiometabolic (CMB) disease risk. Total sleep time and sleep efficiency (percent of time in bed asleep) were assessed via seven nights of wrist actigraphy among 426 participants in the Midlife in the United States Study (31% AA; 69% EA; 61% female; mean age = 56.8 y). CMB risk was indexed as a composite of seven biomarkers [blood pressure, waist circumference, hemoglobin A1c (HbA1c), insulin resistance, triglycerides, HDL cholesterol (HDL-C), and C-reactive protein]. Covariates included sociodemographic characteristics and relevant health behaviors. Results indicated that AAs relative to EAs obtained less sleep (341 vs. 381 min) and had lower sleep efficiency (72.3 vs. 82.2%) (P values < 0.001). Further, 41% and 58% of the racial difference in CMB risk was explained by sleep time and sleep efficiency, respectively. In models stratified by sex, race was indirectly associated with CMB risk via sleep time and efficiency only among females (explaining 33% and 65% of the race difference, respectively). Indirect effects were robust to alternative model specifications that excluded participants with diabetes or heart disease. Consideration of sleep determinants and sleep health is therefore needed in efforts to reduce racial differences in CMB disease.

Ambulatory monitoring demonstrates an acute association between cookstove-related carbon monoxide and blood pressure in a Ghanaian cohort

BACKGROUND

Repeated exposure to household air pollution may intermittently raise blood pressure (BP) and affect cardiovascular outcomes. We investigated whether hourly carbon monoxide (CO) exposures were associated with acute increases in ambulatory blood pressure (ABP); and secondarily, if switching to an improved cookstove was associated with BP changes. We also evaluated the feasibility of using 24-h ambulatory blood pressure monitoring (ABPM) in a cohort of pregnant women in Ghana.

METHODS

Participants were 44 women enrolled in the Ghana Randomized Air Pollution and Health Study (GRAPHS). For 27 of the women, BP was measured using 24-h ABPM; home blood pressure monitoring (HBPM) was used to measure BP in the remaining 17 women. Personal CO exposure monitoring was conducted alongside the BP monitoring.

RESULTS

ABPM revealed that peak CO exposure (defined as ≥4.1 ppm) in the 2 hours prior to BP measurement was associated with elevations in hourly systolic BP (4.3 mmHg [95% CI: 1.1, 7.4]) and diastolic BP (4.5 mmHg [95% CI: 1.9, 7.2]), as compared to BP following lower CO exposures. Women receiving improved cookstoves had lower post-intervention SBP (within-subject change in SBP of -2.1 mmHg [95% CI: -6.6, 2.4] as compared to control), though this result did not reach statistical significance. 98.1% of expected 24-h ABPM sessions were successfully completed, with 92.5% of them valid according to internationally defined criteria.

CONCLUSIONS

We demonstrate an association between acute exposure to carbon monoxide and transient increases in BP in a West African setting. ABPM shows promise as an outcome measure for assessing cardiovascular health benefits of cookstove interventions.

TRIAL REGISTRATION

The GRAPHS trial was registered with clinicaltrials.gov on 13 April 2011 with the identifier NCT01335490 .

Ambulatory Blood Pressure Monitoring in Chinese Patients with Obstructive Sleep Apnea

STUDY OBJECTIVES

Nocturnal blood pressure (BP) dipping in patients with obstructive sleep apnea (OSA) has not yet been well investigated in Chinese patients, in whom the relationship of OSA and body mass index (BMI) is weaker than that in Caucasians. The aim of this study was to evaluate the BP profile, and the relationships between nocturnal BP and the severity of OSA, in Chinese patients.

METHODS

Consecutive Chinese adult outpatients with suspected OSA had overnight polysomnography (PSG), office BP, and 24-h ambulatory BP monitoring (ABPM). The apnea-hypopnea index (AHI) and nocturnal oxygen saturation level were recorded, and BP patterns were classified based on the ABPM.

RESULTS

Fifty-six subjects (40 male and 16 female, 48.59 ± 13.27 y) were evaluated. There were 14 patients with mild OSA (25.0%, AHI: 10.56 ± 3.42 events/h), 16 with moderate OSA (28.6%, AHI: 23.536 ± 3.42 events/h) and 26 with severe OSA (46.4%, AHI: 51.52 ± 3.42 events/h). There were 18 dippers (32.1%), 27 non-dippers (48.2%), and 11 reverse dippers (19.6%). As OSA severity increased, non-dipping also increased. A total of 67.9% of the OSA patients showed overall hypertension on ABPM, 57.1% had daytime hypertension only, and 73.2% had nighttime hypertension.

CONCLUSIONS

OSA severity is associated with 24-h BP profiles in a population with only mild increases in BMI. These results can influence clinical practice, OSA management, and hypertension treatment policies.

Clinic and ambulatory blood pressure in a population-based sample of African Americans: the Jackson Heart Study

Blood pressure (BP) can differ substantially when measured in the clinic versus outside of the clinic setting. Few population-based studies with ambulatory blood pressure monitoring (ABPM) include African Americans. We calculated the prevalence of clinic hypertension and ABPM phenotypes among 1016 participants in the population-based Jackson Heart Study, an exclusively African-American cohort. Mean daytime systolic BP was higher than mean clinic systolic BP among participants not taking antihypertensive medication (127.1[standard deviation 12.8] vs. 124.5[15.7] mm Hg, respectively) and taking antihypertensive medication (131.2[13.6] vs. 130.0[15.6] mm Hg, respectively). Mean daytime diastolic BP was higher than clinic diastolic BP among participants not taking antihypertensive medication (78.2[standard deviation 8.9] vs. 74.6[8.4] mm Hg, respectively) and taking antihypertensive medication (77.6[9.4] vs. 74.3[8.5] mm Hg, respectively). The prevalence of daytime hypertension was higher than clinic hypertension for participants not taking antihypertensive medication (31.8% vs. 14.3%) and taking antihypertensive medication (43.0% vs. 23.1%). A high percentage of participants not taking and taking antihypertensive medication had nocturnal hypertension (49.4% and 61.7%, respectively), white-coat hypertension (30.2% and 29.3%, respectively), masked hypertension (25.4% and 34.6%, respectively), and a nondipping BP pattern (62.4% and 69.6%, respectively). In conclusion, these data suggest hypertension may be misdiagnosed among African Americans without using ABPM.

Effects of exercise and stress management training on nighttime blood pressure dipping in patients with coronary heart disease: A randomized, controlled trial

INTRODUCTION

Blunted nighttime blood pressure (BP) dipping is prognostic of cardiovascular morbidity and mortality. Patients with coronary heart disease (CHD) are often characterized by a blunted nighttime BP dipping pattern. The present study compared the effects of 2 behavioral intervention programs, aerobic exercise (EX) and stress management (SM) training, with a usual care (UC) control group on BP dipping in a sample of CHD patients.

METHODS

This was a secondary analysis of a randomized, controlled trial with allocation concealment and blinded outcome assessment in 134 patients with stable CHD and exercise-induced myocardial ischemia. Nighttime BP dipping was assessed by 24-hour ambulatory BP monitoring, at prerandomization baseline and after 16 weeks of one of the following treatments: usual medical care; UC plus supervised aerobic EX for 35 minutes, 3 times per week; UC plus weekly 1.5-hour sessions of SM training.

RESULTS

The EX and SM groups exhibited greater improvements in systolic BP dipping (P=.052) and diastolic BP dipping (P=.031) compared with UC. Postintervention systolic BP percent-dipping means were 12.9% (SE=1.5) for SM, 11.1% (SE=1.4) for EX, and 8.6% (SE=1.4) for UC. Postintervention diastolic BP percent-dipping means were 13.3% (SE=1.9) for SM, 14.1% (SE=1.8) for EX, and 8.8% (1.8) for UC.

CONCLUSIONS

For patients with stable CHD, EX or SM training resulted in improved nighttime BP dipping compared with usual medical care. These favorable effects of healthy lifestyle modifications may help reduce the risk of adverse clinical events.

Sleep, insomnia, and hypertension: current findings and future directions

Blood pressure (BP) varies over 24 hours. During normal sleep, BP typically decreases by 10% or more. Research suggests that disordered sleep, particularly sleep deprivation and obstructive sleep apnea, is associated with increased BP and risk of hypertension. Less is known about the relationship between insomnia and hypertension. Population-based studies have reported an association between insomnia symptoms and both prevalent and incident hypertension, particularly in the context of short sleep duration. Furthermore, a number of mechanisms have been proposed to explain the relationship between insomnia and hypertension. However, few studies have examined these proposed mechanisms, and even fewer clinical trials have been conducted to determine if improved sleep improves BP and/or reverses a nondipping BP pattern. Methodological concerns, particularly with respect to the diagnosis of insomnia, no doubt impact the strength of any observed association. Additionally, a large majority of studies have only examined the association between insomnia symptoms and clinic BP. Therefore, future research needs to focus on careful consideration of the diagnostic criteria for insomnia, as well as inclusion of either home BP or ambulatory BP monitoring. Finally, clinical trials aimed at improving the quality of sleep should be conducted to determine if improved sleep impacts 24-hour BP.

Dipping in Ambulatory Blood Pressure Monitoring Correlates With Overnight Urinary Excretion of Catecholamines and Sodium

Nondipping blood pressure (BP) is associated with increased morbidity and mortality. This study examines the relationship of "dipping" in 24-hour ambulatory BP monitoring (ABPM) with awake and sleeping urinary norepinephrine (NE) and epinephrine (EPI), and that of urinary NE and EPI with urinary sodium (UNa). Fifty nondippers and 65 dippers were included in the present study. Collected data included age, sex, body mass index, history of hypertension, current antihypertensive treatment, ABPM data, and NE, EPI, and UNa values. Hierarchical multiple regression analysis with the night-to-day ratio (NDR) of systolic BP as a dependent variable showed that the composite term of the NDRs of urinary NE and EPI was a significant predictor for dipping. Results also show a differential role of NE and EPI in circadian UNa excretion in dippers and nondippers. These results indicate that the sympathetic nervous system is involved in the regulation of circadian BP variations and UNa excretion.

Blood Pressure Dipping and Urban Stressors in Young Adult African Americans

BACKGROUND

Blunted nocturnal blood pressure (BP) dipping is an early marker of cardiovascular risk that is prevalent among African Americans.

PURPOSE

We evaluated relationships of BP dipping to neighborhood and posttraumatic stress and sleep in urban residing young adult African Americans.

METHODS

One hundred thirty-six black, predominately African American, men and women with a mean age of 22.9 years (SD = 4.6) filled out surveys and were interviewed and had two, 24-h ambulatory BP recordings.

RESULTS

Thirty-eight percent had BP dipping ratios < .10. Wake after sleep onset (WASO), neighborhood disorder and neighborhood poverty rates but not posttraumatic stress symptoms, and other sleep measures correlated significantly with dipping ratios. Models with the neighborhood measures that also included WASO increased the explained variance.

CONCLUSIONS

Studies elucidating mechanisms underlying effects of neighborhoods on BP dipping and the role of disrupted sleep, and how they can be mitigated are important directions for future research.

Lifestyle modification for resistant hypertension: The TRIUMPH randomized clinical trial

BACKGROUND

Resistant hypertension (RH) is a growing health burden in this country affecting as many as 1 in 5 adults being treated for hypertension. Resistant hypertension is associated with increased risk of adverse cardiovascular disease (CVD) events and all-cause mortality. Strategies to reduce blood pressure (BP) in this high-risk population are a national priority.

METHODS

TRIUMPH is a single-site, prospective, randomized clinical trial to evaluate the efficacy of a center-based lifestyle intervention consisting of exercise training, reduced sodium and calorie Dietary Approaches to Stop Hypertension eating plan, and weight management compared to standardized education and physician advice in treating patients with RH. Patients (n = 150) will be randomized in a 2:1 ratio to receive either a 4-month supervised lifestyle intervention delivered in the setting of a cardiac rehabilitation center or to a standardized behavioral counseling session to simulate real-world medical practice. The primary end point is clinic BP; secondary end points include ambulatory BP and an array of CVD biomarkers including left ventricular hypertrophy, arterial stiffness, baroreceptor reflex sensitivity, insulin resistance, lipids, sympathetic nervous system activity, and inflammatory markers. Lifestyle habits, BP, and CVD risk factors also will be measured at 1-year follow-up.

CONCLUSIONS

The TRIUMPH randomized clinical trial (ClinicalTrials.gov NCT02342808) is designed to test the efficacy of an intensive, center-based lifestyle intervention compared to a standardized education and physician advice counseling session on BP and CVD biomarkers in patients with RH after 4 months of treatment and will determine whether lifestyle changes can be maintained for a year.

Association of sleep characteristics with atrial fibrillation: the Multi-Ethnic Study of Atherosclerosis

BACKGROUND

Population-based studies have linked measures of sleep disordered breathing to nocturnally occurring atrial fibrillation (AF) episodes. Whether measures of sleep disordered breathing and sleep quality are associated with prevalent AF has not been studied in an unselected population. We investigated the cross-sectional association with prevalent AF of objectively collected prespecified measures of overnight sleep breathing disturbances, sleep stage distributions, arousal and sleep duration.

METHODS

AF prevalence, defined by diagnosis codes, study electrocardiography and sleep study were examined among Multi-Ethnic Study of Atherosclerosis (MESA) participants who underwent polysomnography in the MESA Sleep Study (n=2048).

MEASUREMENTS AND MAIN RESULTS

Higher apnoea hypopnoea index (AHI) was associated with increased odds of AF, although the significance was attenuated after full adjustment for covariates including prevalent cardiovascular disease (OR: 1.22 (0.99 to 1.49) per SD (17/h), p=0.06). Analyses of sleep architecture measures and AF revealed significantly lower odds of AF associated with longer duration of slow wave sleep (OR: 0.66 (0.5 to 0.89) per SD (34 min), p=0.01) which persisted after additionally adjusting for AHI (OR: 0.68 (0.51 to 0.92), p=0.01). Higher sleep efficiency was significantly associated with lower likelihood of AF but the significance was lost when adjusted for AHI. No significant association was present between sleep duration and AF. In a model including AHI and arousal index, the association between AHI and AF was strengthened (AHI: OR 1.49 (1.15 to 1.91) per SD, p=0.002) and a significant inverse association between arousal index and AF was observed (OR 0.65 (0.50 to 0.86) per SD (12/h), p=0.005).

CONCLUSIONS

In a study of a large multiethnic population, AF was associated with AHI severity, and was more common in individuals with poor sleep quality as measured by reduced slow wave sleep time, a finding that was independent of AHI.

Short-term exposure to noise, fine particulate matter and nitrogen oxides on ambulatory blood pressure: A repeated-measure study

Exposure to road traffic noise, fine particulate matter (aerodynamic diameter ≤2.5 μm; PM2.5) and nitrogen oxides (NOx) has been associated with transient changes in blood pressure, but whether an interaction exists remains unclear. This panel study investigated whether noise, PM2.5 and NOx exposure were independently associated with changes in 24-h ambulatory blood pressure. We recruited 33 males and 33 females aged 18-32 years as study subjects. Personal noise exposure and ambulatory blood pressure were monitored simultaneously in 2007. During the data collection periods, 24-h data on PM2.5 and NOx from five air-quality monitors within 6 km of participants' home addresses were used to estimate their individual exposures. Linear mixed-effects regression models were used to estimate single and combined effects on ambulatory blood pressure. Exposure to both noise and PM2.5 was significantly associated with increased systolic blood pressure (SBP) and diastolic blood pressure (DBP) over 24h; NOx exposure was only significantly related to elevated DBP. Twenty-four-hour ambulatory blood pressure increased with the current noise exposure of 5 A-weighted decibels (dBA) (SBP 1.44 [95% confidence interval: 1.16, 1.71] mmHg and DBP 1.40 [1.18, 1.61] mmHg) and PM2.5 exposure of 10-µg/m(3) (SBP 0.81 [0.19, 1.43] mmHg and DBP 0.63 [0.17, 1.10] mmHg), as well as the current NOx exposure of 10-ppb (DBP 0.54 [0.12, 0.97] mmHg) after simultaneous adjustment. These findings suggest that exposure to noise and air pollutants may independently increase ambulatory blood pressure and the risk of cardiovascular diseases.