Objective but Not Subjective Short Sleep Duration Is Associated With Hypertension in Obstructive Sleep Apnea

Association between sleep duration and serum neurofilament light chain levels among adults in the United States

Background

Neurofilaments are neuron specific skeleton proteins maintaining axon transduction speed, leaked into cerebrospinal fluid and serum after axonal injury or neuron death. Sleep duration change has long related to many health issues but lack laboratory examination.

Methods

This study enrolled total 10,175 participants from 2013 to 2014 National Health and Nutrition Examination Survey and used a multi-variable linear model to analyze the relationship between sleep duration and serum neurofilament light chain (sNfL) level.

Results

There was a fixed relationship between sleep duration and sNfL level (β = 0.65, p = 0.0280). After adjusted for covariates, this relationship still (β = 0.82, p = 0.0052). Segmented regression showed that the turning point of sleep duration was 7 h 1 h decrease in sleep duration was significantly associated with -1.26 higher sNfL level (95 % CI: 2.25, -0.28; p = 0.0115) when sleep duration <7 h; however, 1 h increase in sleep duration was significantly associated with 3.20 higher sNfL level (95 % CI: 2.13, 4.27; p < 0.0001) when sleep duration >7 h. Furthermore, the stratified analysis indicated that the associations between sleep duration and sNfL level were stronger among those normal body mass index and trouble sleeping (p-interaction <0.0001 and 0.0003).

Conclusion

In summary, there was a J-shaped relationship between sleep duration and sNfL level in the United States of America representative group, these may suggest that extreme sleep duration can be deleterious judged by sNfL level. And still need large cohort study to determine the accurate relationship, and cluster analysis to infer the nervous disease connected with extreme sleep duration.

Association of accelerometer-measured sleep duration and different intensities of physical activity with incident type 2 diabetes in a population-based cohort study

PURPOSE

The aim of the current study was to investigate the association of accelerometer-measured sleep duration and different intensities of physical activity (PA) with the risk of incident type 2 diabetes in a population-based prospective cohort study.

METHODS

Altogether, 88,000 participants (mean age = 62.2 ± 7.9 years, mean ± SD) were included from the UK Biobank. Sleep duration (short: <6 h/day; normal: 6-8 h/day; long: >8 h/day) and PA of different intensities were measured using a wrist-worn accelerometer over a 7-day period between 2013 and 2015. PA was classified according to the median or World Health Organization-recommendation: total volume of PA (high, low), moderate-to-vigorous PA (MVPA) (recommended, not recommended), and light-intensity PA (high, low). Incidence of type 2 diabetes was ascertained using hospital records or death registries.

RESULTS

During a median follow-up of 7.0 years, 1615 incident type 2 diabetes cases were documented. Compared with normal sleep duration, short (hazard ratio (HR) = 1.21, 95% confidence interval (95%CI): 1.03-1.41) but not long sleep duration (HR = 1.01, 95%CI: 0.89-1.15) was associated with excessive type 2 diabetes risk. This increased risk among short sleepers seems to be protected against by PA. Compared with normal sleepers with high or recommended PA, short sleepers with low volume of PA (HR = 1.81, 95%CI: 1.46-2.25), not recommended (below the World Health Organization-recommended level of) MVPA (HR = 1.92, 95%CI: 1.55-2.36), or low light-intensity PA (HR = 1.49, 95%CI: 1.13-1.90) had a higher risk of type 2 diabetes, while short sleepers with a high volume of PA (HR = 1.14, 95%CI: 0.88-1.49), recommended MVPA (HR = 1.02, 95%CI: 0.71-1.48), or high light-intensity PA (HR = 1.14, 95%CI: 0.92-1.41) did not.

CONCLUSION

Accelerometer-measured short but not long sleep duration was associated with a higher risk of incident type 2 diabetes. A higher level of PA, regardless of intensity, potentially ameliorates this excessive risk.

Objective Sleep Duration and All-Cause Mortality Among People With Obstructive Sleep Apnea

Importance

The association between sleep duration and all-cause mortality remains unclear among people with obstructive sleep apnea (OSA).

Objective

To explore whether there is an association between sleep duration and all-cause mortality among people with OSA.

Design, Setting, and Participants

This cohort study investigated participants with OSA from the Sleep Heart Health Study (SHHS) in which participants were enrolled between 1995 and 1998 with questionnaires and polysomnography (PSG) assessment and followed up for a median of 11.8 years. SHHS was a multicenter community-based study; 2574 participants with OSA defined by apnea-hypopnea index (AHI) greater than or equal to 15 from SHHS were found; all of them had all-cause mortality data and were included in the study. Data were analyzed from November 2022 to October 2023.

Exposures

Participants were divided into 4 groups with objective sleep duration of (1) at least 7 hours, (2) 6 to less than 7 hours, (3) 5 to less than 6 hours, and (4) less than 5 hours, which was determined by total sleep time on PSG at baseline.

Main Outcomes and Measures

All-cause mortality was defined as deaths from any cause and its risk was compared among 4 OSA groups using Cox regression models.

Results

A total of 2574 participants with OSA were included (1628 [63.2%] men and 946 [36.8%] women; mean [SD] age, 65.4 [10.7] years; 211 [8.2%] Black, 2230 [86.6%] White, 133 [5.2%] other race). Overall, 688 all-cause deaths were observed in participants. Compared with the group sleeping at least 7 hours, the groups sleeping 6 to less than 7 hours (hazard ratio [HR], 1.53 [95% CI, 1.13-2.07]), 5 to less than 6 hours (HR, 1.40 [95% CI, 1.03-1.90]), and less than 5 hours (HR, 1.64 [95% CI, 1.20-2.24]) had significantly higher risks of all-cause mortality independent of AHI. Sensitivity analyses were performed among participants with available data of positive airway pressure treatment during follow-up and the finding was mostly consistent, albeit the HR for the group of 5 to less than 6 hours was not statistically significant.

Conclusions and Relevance

In this cohort study of 2574 participants with OSA, those with shorter objective sleep duration had higher risk of all-cause mortality independent of AHI compared with those sleeping at least 7 hours. Further studies would be needed to investigate health benefits of extending sleep length among people with OSA with short sleep duration.

Clinical phenotypes of obstructive sleep apnea: a cluster analysis based on sleep perception and sleep quality

PURPOSE

To determine obstructive sleep apnea (OSA) phenotypes using cluster analysis including variables of sleep perception and sleep quality and to further explore factors correlated with poor sleep quality in different clusters.

METHODS

This retrospective study included patients with OSA undergoing polysomnography (PSG) between December 2020 and April 2022. Two-step cluster analysis was performed to detect distinct clusters using sleep perception variables including discrepancy in total sleep time (TST), sleep onset latency (SOL), and wakefulness after sleep onset (WASO); objective TST, SOL, and WASO; and sleep quality. One-way analysis of variance or chi-squared tests were used to compare clinical and PSG characteristics between clusters. Binary logistic regression analyses were used to explore factors correlated with poor sleep quality.

RESULTS

A total of 1118 patients were included (81.6% men) with mean age ± SD 43.3 ± 13.1 years, Epworth sleepiness score, 5.7 ± 4.4, and insomnia severity index 3.0 ± 2.4. Five distinct OSA clusters were identified: cluster 1 (n = 254), underestimated TST; cluster 2 (n = 158), overestimated TST; cluster 3 (n = 169), overestimated SOL; cluster 4 (n = 155), normal sleep discrepancy and poor sleep quality; and cluster 5 (n = 382), normal sleep discrepancy and good sleep quality. Patients in cluster 2 were older, more commonly had hypertension, and had the lowest apnea-hypopnea index and oxygen desaturation index. Age and sleep efficiency were correlated with poor sleep quality in clusters 1, 2, and 5, and also AHI in cluster 2.

CONCLUSION

Subgroups of patients with OSA have different patterns of sleep perception and quality that may help us to further understand the characteristics of sleep perception in OSA and provide clues for personalized treatment.

Is the Gut Microbiome Implicated in the Excess Risk of Hypertension Associated with Obstructive Sleep Apnea? A Contemporary Review

Obstructive sleep apnea (OSA) is a highly prevalent sleep disorder and an established risk factor for cardiovascular diseases, including hypertension. The pathogenesis of elevated blood pressure (BP) in OSA is multifactorial, including sympathetic overdrive, vascular aberrations, oxidative stress, inflammation, and metabolic dysregulation. Among the mechanisms potentially involved in OSA-induced hypertension, the role of the gut microbiome is gaining increasing attention. Perturbations in the diversity, composition, and function of the gut microbiota have been causally linked to numerous disorders, and robust evidence has identified gut dysbiosis as a determinant of BP elevation in various populations. In this brief review, we summarize the current body of literature on the implications of altered gut microbiota for hypertension risk in OSA. Data from both preclinical models of OSA and patient populations are presented, and potential mechanistic pathways are highlighted, along with therapeutic considerations. Available evidence suggests that gut dysbiosis may promote the development of hypertension in OSA and may thus be a target for interventions aimed at attenuating the adverse consequences of OSA in relation to cardiovascular risk.

Adherence to CPAP in summer to autumn predicts self-reported common cold symptoms in patients with obstructive sleep apnea in winter: A prospective observational study

OBJECTIVE

We conducted a prospective observational study to determine the relationship between adherence to continuous positive airway pressure (CPAP) and susceptibility to the common cold in moderate-to-severe obstructive sleep apnea (OSA) patients.

METHODS

We prospectively investigated the number of days with common cold symptoms from November 2019 to February 2020. The rate of CPAP use for 4 h/night in the preceding four months (July to October 2019) was used as a measure of CPAP adherence. Multiple generalized linear models were used to evaluate the association to days of common cold symptoms after controlling for demographic variables, habitual short sleep duration, and insomnia severity.

RESULTS

We included 123 outpatients (median age 63 years) with moderate-to-severe OSA treated with CPAP. In the multivariate generalized linear model, better CPAP adherence was independently significantly associated with days with fewer common cold symptoms (β = -0.248, P = 0.031); meanwhile, the severity of insomnia and habitual short sleep duration was not significantly associated with it. Subgroup analyses revealed that the association between CPAP adherence and days with common cold symptoms was also significant in young to middle-aged (<65 years) participants (β = -0.407, P = 0.005). In contrast, the association was negligible in older (≥65 years) participants.

CONCLUSIONS

CPAP adherence may be protective against viral infections in patients with moderate-to-severe OSA. This effect appears to be more pronounced in young to middle-aged patients with OSA.

Relative spectral power quantifying the distribution of intermittent hypoxemia in obstructive sleep apnea is strongly associated with hypertension

STUDY OBJECTIVES

To investigate the association between the periodicity of distribution of intermittent hypoxemia (IH) and hypertension in adults with obstructive sleep apnea (OSA) and search for an index to quantify the association.

METHODS

Samples were derived from two cross-sectional studies: The Sleep Heart Health Study (SHHS) including 3991 adults with age 64.7 ± 10.9 years; and the Chinese Changgung Sleep Health Study (CSHS) including 906 adults with age 59.5 ± 12.4 years. Spectral analysis of peripheral oxygen saturation (SpO₂) was performed and the relative spectral power (PFR) in the frequency band of 0.011-0.037 Hz (PFR_{0.011-0.037Hz}) was extracted to quantify the periodic distribution of IH. Multiple logistic regression models were used to calculate the partially and fully adjusted odd ratios for PFR_{0.011-0.037Hz}.

RESULTS

PFR_{0.011-0.037Hz} was significantly higher in the hypertension group than non-hypertension group (44.4% ± 0.3% vs. 42.1% ± 0.3%, p < 0.001 in SHHS and 57.4% ± 0.7% vs. 50.5% ± 0.8%, p < 0.001 in CSHS). In the fully adjusted model, individuals in the SHHS with PFR_{0.011-0.037Hz} in the highest quintiles had an odd ratio of 1.33 [95% confidence interval (CI) 1.06-1.67]. Similarly, the group in the CSHS with PFR_{0.011-0.037Hz} in the highest quintile had an odd ratio of 3.08 (95% CI 1.80-5.28).

CONCLUSIONS

We developed an IH distribution measure which is strongly associated with hypertension independent of multiple confounding variables. The finding suggests that the periodic distribution of sleep related upper airway obstructions is an essential hypertension characterizing feature.

Sleep fragmentation during rapid eye movement sleep and hypertension in obstructive sleep apnea

OBJECTIVE

Sleep fragmentation determined by repetitive arousals from sleep in obstructive sleep apnea (OSA) is associated with hypertension. We aimed to quantify the independent association of arousals during rapid eye movement (REM)/non-rapid eye movement (NREM) sleep with prevalent hypertension.

METHODS

We included adults with 4 h of total sleep time and at least 30 min of REM sleep obtained from overnight in-laboratory polysomnography. Logistic regression models were fitted to explore the association between arousals during REM/NREM sleep and prevalent hypertension. All models controlled for OSA metrics and arousals during NREM/REM sleep, either by statistical adjustment or by stratification.

RESULTS

The sample comprised of 11 643 patients, of which 10 055 were OSA patients. Fully adjusted models demonstrated significant dose-relationships between arousal index during REM sleep (AI-REM) and prevalent hypertension (P trend = 0.002). The higher relative odds of prevalent hypertension were most evident with AI-REM > 40 events/h. In OSA patients with arousal index during NREM sleep (AI-NREM) <15 events/h, every10-unit increase in the AI-REM was associated with 18% higher odds of hypertension (odds ratio, 1.18; 95% confidence interval, 1.11-1.27) in OSA. On the contrary, AI-NREM was not a significant predictor of hypertension in any of the models.

CONCLUSIONS

Our findings indicate that arousals during REM sleep are associated with prevalent hypertension. This is clinically relevant because treatment of OSA is often limited to the first half of the sleep period leaving most of sleep fragmentation during REM sleep untreated.

The effect and relative importance of sleep disorders for all-cause mortality in middle-aged and older asthmatics

Background

Previous studies observed that sleep disorders potentially increased the risk of asthma and asthmatic exacerbation. We aimed to examine whether excessive daytime sleepiness (EDS), probable insomnia, objective short sleep duration (OSSD), and obstructive sleep apnea (OSA) affect all-cause mortality (ACM) in individuals with or without asthma.

Methods

We extracted relevant data from the Sleep Heart Health Study established in 1995–1998 with an 11.4-year follow-up. Multivariate Cox regression analysis with a proportional hazards model was used to estimate the associations between ACM and four sleep disorders among asthmatic patients and individuals without asthma. Dose-response analysis and machine learning (random survival forest and CoxBoost) further evaluated the impact of sleep disorders on ACM in asthmatic patients.

Results

A total of 4538 individuals with 990 deaths were included in our study, including 357 asthmatic patients with 64 deaths. Three multivariate Cox regression analyses suggested that OSSD (adjusted HR = 2.67, 95% CI: 1.23–5.77) but not probable insomnia, EDS or OSA significantly increased the risk of ACM in asthmatic patients. Three dose-response analyses also indicated that the extension of objective sleep duration was associated with a reduction in ACM in asthmatic patients compared to very OSSD patients. Severe EDS potentially augmented the risk of ACM compared with asthmatics without EDS (adjusted HR = 3.08, 95% CI: 1.11–8.56). Machine learning demonstrated that OSSD of four sleep disorders had the largest relative importance for ACM in asthmatics, followed by EDS, OSA and probable insomnia.

Conclusions

This study observed that OSSD and severe EDS were positively associated with an increase in ACM in asthmatic patients. Periodic screening and effective intervention of sleep disorders are necessary for the management of asthma.

Difficulty initiating sleep in patients with heart failure: Impact of left atrial pressure

BACKGROUND

Patients with heart failure (HF) often complain of sleep discomfort. Previous reports described that difficulty initiating sleep increased the cardiovascular risk in the general population. However, the association between difficulty initiating sleep and cardiac function in patients with HF remains unclear. This study aimed to investigate the associations between difficulty initiating sleep and clinical characteristics and cardiac function in patients with HF.

METHODS

Eighty-seven patients with HF who underwent overnight polysomnography for suspected sleep-disordered breathing were included. Patients were divided into two groups of the longer sleep latency (SL) group (SL ≥14 min, n = 44) and the shorter SL group (SL <14 min, n = 43). The median value of SL was defined as the time from lights-off to falling asleep. We compared the patients' characteristics, laboratory data, and polysomnographic and echocardiographic indices between the two groups.

RESULTS

The patients' median age was 67 years, and 85.1 % were men. There was lower beta blocker use [25 (56.8 %) vs. 34 (79.1 %), p = 0.046] and a higher peak mitral early filling velocity to mitral annular velocity ratio (E/e') [16.5 (14.2-21.7) vs. 13.7 (10.9-16.2), p = 0.005] in the longer SL group than in the shorter SL group. In multivariate logistic analysis, E/e' (odds ratio: 1.10, 95 % confidence interval: 1.01 to 1.19; p = 0.032) and systolic blood pressure before sleeping (odds ratio: 1.05, 95 % confidence interval: 1.00 to 1.10; p = 0.033) were significantly associated with a longer SL in patients with HF.

CONCLUSIONS

Increased left atrial pressure suggested by increased E/e' and increased systolic blood pressure before sleeping is independently associated with difficulty initiating sleep in patients with HF. Management of these hemodynamic imbalances is required to improve difficulty initiating sleep in patients with HF.

Obstructive Sleep Apnea and Hypertension: Updates to a Critical Relationship

Purpose of Review

Obstructive sleep apnea (OSA) is an underdiagnosed illness linked to essential hypertension (HTN), resistant hypertension (r-HTN), and cardiovascular disease (CVD). This review provides updates on the epidemiology, pathophysiology, and treatments of OSA-associated HTN.

Recent Findings

Mild sleep apnea increases the risk for HTN. Eighty-nine percent of young patients aged 18–35 with HTN not attributed to secondary causes have underlying OSA. Home sleep studies are noninferior to formal polysomnography for OSA diagnosis. Nocturnal oxygen desaturation rate is positively correlated with HTN severity. Gut microbiome neo-colonization in response to high-fat diet cravings in patients with OSA alters immune function and worsens HTN. Carbonic anhydrase inhibitors and probiotics show newfound potential for OSA-associated HTN treatment. OSA recognition improves hospital outcomes after a STEMI. Hypoxia-inducible factor (HIF) transcription increases in a dose-dependent manner to hypoxia, and HIFs are strongly linked to cancer growth.

Summary

OSA and HTN are comorbid conditions with adversely connected pathophysiology including sympathetic hyperactivity, gut dysbiosis, proinflammation, endothelial damage, rostral fluid shifts, pharyngeal collapse, intravascular fluid retention, nocturnal energy expenditure, and metabolic derangements. The dose–response effect of OSA on HTN severity challenges blood pressure (BP) control, so those with refractory HTN should be screened for OSA.

Development and validation of a clinical model to predict hypertension in consecutive patients with obstructive sleep apnea hypopnea syndrome: a hospital-based study and nomogram analysis

BACKGROUND

To screen for risk predictors of hypertension in patients with Obstructive Sleep Apnea Hypopnea Syndrome (OSAHS) and develop and validate a clinical model for individualized prediction of hypertension in consecutive patients with OSAHS.

METHODS

114 consecutive patients with OSAHS confirmed by PSG monitoring participated in this study. Those individuals were divided into two sets at a ratio of 7:3, using computer-generated random numbers: 82 individuals were assigned to the training set and 32 to the validation set. Important risk predictors of hypertension in individuals with OSAHS were confirmed using the LASSO method and a clinical nomogram constructed. The predictive accuracy was assessed by unadjusted concordance index (C-index) and calibration plot.

RESULTS

Univariate and multivariate regression analysis identified BMI, REM-AHI, REM-MSpO₂ and T90% as predictive risk factors of OSAHS. Those risk factors were used to construct a clinical predictive nomogram. The calibration curves for hypertension in patients with OSAHS risk revealed excellent accuracy of the predictive nomogram model, internally and externally. The unadjusted concordance index (C-index) for the training and validation set was 0.897 [95% CI 0.795-0.912] and 0.894 [95% CI 0.788-0.820] respectively. The AUC of the training and validation set was 0.8175882 and 0.8031522, respectively. Decision curve analysis showed that the predictive model could be applied clinically when the threshold probability was 20 to 80%.

CONCLUSION

We constructed and validated a clinical nomogram to individually predict the occurrence of hypertension in patients with OSAHS. We determined that BMI, REM-AHI, REM-MSpO₂ and T90% were independent risk predictors for hypertension in patients with OSAHS. This practical prognostic nomogram may help improve clinical decision making.

Short Sleep Duration and Erectile Dysfunction: A Review of the Literature

The meaning of sleep has puzzled people for millennia. In modern society, short sleep duration is becoming a global problem. It has been established that short sleep duration can increase the risk of several diseases, such as cardiovascular and metabolic diseases. Currently, a growing body of research has revealed a possible link between sleep disorders and erectile dysfunction (ED). However, the mechanisms linking short sleep duration and ED are largely unknown. Thus, we provide a review of clinical trials and animal studies. In this review, we propose putative pathways connecting short sleep duration and ED, including neuroendocrine pathways and molecular mechanisms, aiming to pave the way for future research. Meanwhile, the assessment and improvement of sleep quality should be recommended in the diagnosis and treatment of ED patients.

The Effect of Short Sleep Duration on the Development of Asthma

Asthma is regarded as a heterogeneous disease with chronic airway inflammation and reversible airway limitation. Asthma itself and recurrent attacks of asthma can decrease sleep duration and increase the prevalence of short sleep duration. Systemic low-grade inflammation and obesity caused by short sleep duration have been known for a long time, which potentially affect the development of asthma. It would be interesting to study the interaction between short sleep duration and asthma. However, there are relatively few studies and no review about the association between short sleep duration and asthma. This article performed a review about the relationships between short sleep duration and asthmatic phenotype, laboratory tests, comorbidity, and clinical outcomes. Pooled studies about short sleep duration and asthma provided following four results: (1) compared with healthy sleep duration, short sleep duration seemingly increased the risk of central obesity in asthmatics; (2) short sleep duration potentially reduced the level of FeNO and increased lung function impairment in patients with asthma; (3) asthmatic comorbidities, mainly obesity and depression, were negatively associated with short sleep duration among asthmatics; (4) short sleep duration potentially increased the risks of asthma-related hospitalization and emergency care. However, almost all studies are based on subjective but not objective sleep duration. In addition, the study on sleep duration and cause-specific mortality in patients with asthma is relatively scant. Considering the effect of short sleep duration on the development of asthma, we recommend that periodic sleep monitoring for asthmatic management is very necessary.

Association Between Arousals During Sleep and Hypertension Among Patients With Obstructive Sleep Apnea

Background

Sleep fragmentation induced by repetitive arousals is a hallmark of obstructive sleep apnea (OSA). Sleep fragmentation has been linked to hypertension in community‐based studies, but it is unclear if this association is manifest in OSA. We aimed to explore whether frequent arousals from sleep modify the relationship between OSA and prevalent hypertension.

Methods and Results

A total of 10 102 patients with OSA and 1614 primary snorers were included in the study. Hypertension was defined on either direct blood pressure measures or diagnosis by a physician. Spontaneous, respiratory, and movement arousals were derived by polysomnography. Logistic regression models were used to estimate the associations between arousals and prevalent hypertension in patients with OSA and primary snorers. For every 10‐unit increase of total arousal index, odds of hypertension significantly increased in both the total sample (odds ratio [OR], 1.08; 95% CI, 1.03–1.14; P=0.002) and patients with OSA (OR, 1.10; 95% CI, 1.04–1.16; P<0.001), but not in the primary snoring group. Total arousal index was significantly associated with systolic blood pressure and diastolic blood pressure in the total sample (β=0.05 and β=0.06; P<0.001) and in patients with (β=0.05 and β=0.06; P<0.01), but not in primary snorers. In addition, a greater influence of respiratory events with arousals than respiratory events without arousals on blood pressure in OSA was also noted. Results were independent of confounders, including apnea‐hypopnea index and nocturnal hypoxemia.

Conclusions

We conclude that repetitive arousals from sleep are independently associated with prevalent hypertension in patients with OSA.

Socioeconomic status impacts blood pressure response to positive airway pressure treatment

STUDY OBJECTIVES

Positive airway pressure (PAP) treatment of obstructive sleep apnea (OSA) reduces blood pressure (BP). Retrospective data suggest that African Americans (AA), a group at high-risk for hypertensive organ dysfunction, may have a greater BP response to PAP therapy than European Americans (EA). We examined the difference in 24-hour BP response to three months of PAP treatment between AA and EA.

METHODS

Participants (N=259, 161 AA and 98 EA) with apnea-hypopnea index (AHI) ≥15/hour from two prospective cohorts were included. T-tests and multiple linear regression were used to examine BP outcomes in AA vs. EA, adjusting for PAP adherence, socioeconomic status (SES), and baseline characteristics.

RESULTS

Participants were middle-aged (mean ± standard deviation, 53.8±9.3 years), 86% (227) men, AHI 35.6±19.2/hour, and PAP adherence of 3.36±2.24 hours/day. The reductions in 24-hour systolic and diastolic BP (mm Hg) were not different in AA vs. EA (systolic=-1.13±12.1 vs. -0.61±12.8, p=0.80 and diastolic=-0.74±7.9 vs. -0.80±7.4, p=0.96), and race was not a predictor of 24-hour systolic or diastolic BP reduction (p=0.75 and 0.54). SES and PAP adherence demonstrated a significant interaction; low SES was associated with an increase in 24-hour systolic BP (β=19.3, p=0.03) in the absence of PAP use but a greater reduction in 24-hour systolic BP with higher PAP adherence (β=-3.96, p=0.03).

CONCLUSIONS

24-hour BP response to PAP treatment is similar in AA and EA. Adherence to PAP treatment is more effective in improving 24-hour systolic BP in those with low SES.

The study was a clinical trial. Clinical Trial Registration: NCT01960465 and NCT01578031.

Association of Craniofacial and Upper Airway Morphology with Cardiovascular Risk in Adults with OSA

BACKGROUND AND OBJECTIVE

Clinical and population-based studies have demonstrated a strong association between obstructive sleep apnea (OSA) and cardiovascular disease (CVD). Anatomical abnormalities of the craniofacial region and upper airway are important risk factors for OSA. The objective of this study was to investigate the association of craniofacial and upper airway morphology with CVD risk biomarkers.

METHODS

One hundred and sixty-nine male patients with OSA underwent in-laboratory polysomnography (PSG) and upper airway computed tomography (CT) scanning. Ten-year Framingham CVD risk score (FRS) was calculated and categorized into low- and moderate-to-high-risk groups. N-terminal pro B-type natriuretic peptide (NT-proBNP) was measured as a biomarker of increased myocardial wall stress.

RESULTS

Compared to the low-risk group, total sleep time (TST), the proportion of N3 (N3%) and mean oxygen saturation (SpO2mean) were lower, while the arousal index of non-rapid eye movement (NREM) sleep, apnea index (AI) of NREM sleep, apnea hypopnea index (AHI) of NREM sleep, oxygen desaturation index (ODI) and percentage of total sleep time spent with oxyhemoglobin saturation below 90% (TST90) were higher in the moderate-to-high risk group. The corrected upper airway length (UAL), ANB angle and gonion-gnathion-hyoid angle were larger for subjects in the moderate-to-high risk group than those in the low-risk group. In multiple regression analysis, TST, AINREM and adjusted UAL were independently associated with moderate-to-high CVD risk. Plasma NT-proBNP levels were higher in patients in the moderate- to high-risk group, and among the PSG and CT scan parameters, only SPO2mean was marginally associated with NT-proBNP (r=0.183, P=0.054).

CONCLUSION

Craniofacial and upper airway features may contain valid cues about CVD risk, and sleep duration, obstructive event type and occurrence phase may be closely related to CVD risk for patients with OSA.

Longitudinal sleep characteristics and hypertension status: results from the Wisconsin Sleep Cohort Study

AIMS

Sleep characteristics such as short sleep duration or sleep-disordered breathing are established predictors of hypertension. However, few studies have used in-lab polysomnography with a longitudinal design to measure how hypertension is associated with different sleep stages over time. The purpose of this study is to examine whether hypertension is associated with the longitudinal course of sleep quality over time.

METHODS

The current study evaluated data from the Wisconsin Sleep Cohort Study, which consists of 1525 adults in a community-based population of middle-aged to older adults followed for approximately 12-25 years. Sleep characteristics were objectively measured using polysomnography and subjectively assessed using a self-report questionnaire on insomnia complaints. We used linear mixed-effects regression models and cumulative logit models to assess whether the interaction of hypertension and time is associated with objective and subjective sleep.

RESULTS

We found people with hypertension exhibited a greater decline in total sleep time in rapid eye movement sleep (%) over time than those without hypertension (P < 0.05). Individuals with hypertension had less decline in % N3 sleep over time than those without hypertension (P < 0.05). Among the subjective insomnia complaints, our findings indicate hypertensive individuals have a higher probability of having higher levels of 'difficulties in falling asleep' compared with people without hypertension.

CONCLUSION

These findings suggest that hypertension is associated with modified longitudinal changes of objective and subjective sleep characteristics.

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.

Moderating Effect of BMI on the Relationship Between Sympathetic Activation and Blood Pressure in Males with Obstructive Sleep Apnea

BACKGROUND

Sympathetic activation is a primary mechanism mediating increased blood pressure (BP) in obstructive sleep apnea (OSA). However, the relationships between overweight/obesity, sympathetic activation and BP in OSA are not well understood. We hypothesized that increased sympathetic drive is associated with increased BP in normal weight, but not in overweight/obese males with OSA. We therefore examined the effects of body mass index (BMI) on the association between sympathetic activation and BP in males with OSA.

METHODS

We studied 115 males with OSA recruited consecutively from clinic. Twenty-four-hour urinary norepinephrine was used to assess sympathetic activation. Blood pressure was measured both in the evening and in the morning. Hypertension was defined based on either BP measurements or an existing diagnosis. Linear and logistic regressions were conducted to examine the associations between sympathetic activation and both BP and risk of hypertension.

RESULTS

We found 24-hour urinary norepinephrine levels were associated with systolic and diastolic BP (SBP, β=0.157, p=0.082; DBP, β=0.212, p=0.023) and mean arterial pressure (MAP, β=0.198, p=0.032) after adjusting for confounders. Interestingly, these associations were modified by overweight/obesity. After adjusting for confounders, increased 24-hour urinary norepinephrine levels were significantly associated with elevated SBP (β=0.454, p=0.012), DBP (β=0.399, p=0.041), and MAP (β=0.432, p=0.023) in normal weight, but not in overweight/obese patients (all p>0.2). Similar findings were observed in the associations between 24-hour urinary norepinephrine levels and hypertension.

CONCLUSION

Sympathetic activation is associated with elevated BP in normal weight but not in overweight/obese males with OSA, suggesting that BMI may moderate the association between sympathetic activation and BP in males with OSA.

Slow-wave sleep is associated with incident hypertension in patients with obstructive sleep apnea: a cross-sectional study

OBJECTIVE

This study aimed to examine the association between slow-wave sleep ([SWS] N3 stage) and the risk of hypertension in patients with obstructive sleep apnea (OSA) or primary snorers.

METHODS

A retrospective cross-sectional study of 1145 participants who were evaluated for suspected OSA at our Sleep Medical Center were included. Among these participants, 1022 had OSA and 123 were primary snorers. Logistic regression modeling was performed to evaluate the association between the prevalence of hypertension and combined OSA and SWS based on polysomnographic measurements.

RESULTS

Patients with OSA in the lowest SWS quartile (quartile 1,  < 2.0%) showed a two-fold increased risk of hypertension after adjustment for confounding factors compared with primary snorers (odds ratio, 2.13 [95% confidence interval 1.54-2.06]). In logistic analysis stratified according to SWS quartiles, there was no significant difference in the risk of hypertension between patients with OSA and primary snorers in quartile 1. However, in the highest quartile (quartile 4), SWS was significantly associated with incident hypertension in patients with OSA rather than primary snorers.

CONCLUSION

SWS is associated with prevalent hypertension in patients with OSA. Notably, a low proportion of SWS confers a stronger association with incident hypertension than OSA.

Understanding the pathophysiological mechanisms of cardiometabolic complications in obstructive sleep apnoea: towards personalised treatment approaches

In January 2019, a European Respiratory Society research seminar entitled "Targeting the detrimental effects of sleep disturbances and disorders" was held in Dublin, Ireland. It provided the opportunity to critically review the current evidence of pathophysiological responses of sleep disturbances, such as sleep deprivation, sleep fragmentation or circadian misalignment and of abnormalities in physiological gases such as oxygen and carbon dioxide, which occur frequently in respiratory conditions during sleep. A specific emphasis of the seminar was placed on the evaluation of the current state of knowledge of the pathophysiology of cardiovascular and metabolic diseases in obstructive sleep apnoea (OSA). Identification of the detailed mechanisms of these processes is of major importance to the field and this seminar offered an ideal platform to exchange knowledge, and to discuss pitfalls of current models and the design of future collaborative studies. In addition, we debated the limitations of current treatment strategies for cardiometabolic complications in OSA and discussed potentially valuable alternative approaches.

Association of self-reported sleep duration and quality with BaPWV levels in hypertensive patients

The association between sleep conditions and arterial stiffness remains inconclusive. We aimed to investigate the relationship of sleep duration and quality with brachial-ankle pulse-wave velocity (baPWV) in hypertensive patients. A total of 14,485 hypertensive adults were included in this cross-sectional analysis. Information about sleep duration and quality was obtained via questionnaire. A baPWV level ≥1800 cm/s was defined as indicative of arterial stiffness. Compared with participants with a sleep duration <8 h per day, participants with a sleep duration ≥8 h per day had a significantly higher baPWV level (β = 13.7 cm/s; 95% CI: 3.9, 23.5) and a nonsignificantly higher prevalence of arterial stiffness (39.7% vs. 33.0%; OR, 1.08; 95% CI: 0.99-1.19). Similarly, compared with participants with good or medium sleep quality, participants with poor sleep quality had a significantly higher baPWV level (β = 16.3 cm/s; 95% CI: 0.1, 32.6) and a nonsignificantly greater prevalence of arterial stiffness (36.6% vs. 35.3%; OR, 1.13; 95% CI: 0.97-1.32). When sleep duration and quality were examined jointly, participants with a sleep duration ≥8 h and/or poor sleep quality had a significantly higher baPWV level (β = 14.4 cm/s; 95% CI: 5.3, 23.4) and a greater prevalence of arterial stiffness (38.8% vs. 32.7%; OR, 1.10; 95% CI: 1.01-1.20) than those with a sleep duration <8 h and good/medium sleep quality. In summary, among hypertensive patients, a longer sleep duration (≥8 h per day) and poor sleep quality were associated with higher baPWV levels and a higher prevalence of arterial stiffness.

Interaction between obstructive sleep apnea and short sleep duration on insulin resistance: a large-scale study : OSA, short sleep duration and insulin resistance

Objectives

Both short sleep duration and obstructive sleep apnea (OSA) seem to be associated with insulin resistance. We aimed to explore whether short sleep duration modifies the relationship between OSA and insulin resistance.

Methods

Participants were consecutively enrolled from our sleep center during the period from 2007 to 2017. The index of homeostasis model assessment insulin resistance (HOMA-IR) was calculated from insulin and glucose. Sleep duration was determined by standard polysomnography. The associations between sleep duration and insulin resistance were estimated by logistic regression analyses.

Results

A total of 5447 participants (4507 OSA and 940 primary snorers) were included in the study. OSA was independently correlated with insulin resistance after adjusting for all potential confounders (OR, 1.319; 95% CI, 1.088–1.599), but not short sleep duration. In stratified analysis by sleep duration, compared with primary snorers, in the OSA group only extremely short sleep duration (< 5 h) was significantly associated with insulin resistance after adjusting for all covariates (OR, 2.229; 95% CI, 1.283–3.874). Rapid eye movement predominant OSA was significantly associated with insulin resistance (OR = 1.355, 95% CI: 1.019–1.802) after adjustment for confounding factors including age, sex and body mass index.

Conclusions

OSA, but not short sleep duration, was independently associated with insulin resistance. It is worth noting that OSA combined with extremely short sleep duration showed a greater detrimental effect than OSA itself with regard to insulin resistance.

Relationship between Cortisol Changes during the Night and Subjective and Objective Sleep Quality in Healthy Older People

The aim of this study was to investigate whether the nighttime cortisol release was associated with subjective and objective sleep quality and the discrepancy between them. Forty-five healthy older adults (age range from 56 to 75 years) collected salivary samples immediately before sleep and immediately after awakening on two consecutive nights. Actigraphy was used to assess objective sleep quality and quantity. A sleep diary was used to assess subjective sleep quality. Linear mixed models were performed using subjective and objective sleep quality data from 76 nights to investigate between-subject associations. We observed that larger changes in cortisol levels between sleep onset and awakening, reflecting a healthier circadian rhythm of the Hypothalamic-Pituitary-Adrenal (HPA) axis, were associated with better subjective sleep quality, but not with objective sleep quality. Moreover, smaller changes in nighttime cortisol were associated with lower subjective sleep quality relative to objective sleep quality. All these results were observed even after controlling for important confounders such as sleep quantity, age, sex, subjective socioeconomic status, stress perception, depression, physical activity, and adherence to the salivary sampling protocol. This study demonstrates that subjective sleep quality in older people may be explained, to some extent, by the activity of the HPA axis.

Sleep duration and risk of cardiovascular events: The SAVE study

Background and aim

Controversy exists regarding cardiovascular risk in relation to sleep duration. We determined sleep duration and major recurrent cardiovascular event associations in patients with obstructive sleep apnoea and established cardiovascular disease.

Methods

Secondary analyses of the international, multicenter, Sleep Apnea Cardiovascular Endpoints trial. Sleep duration was estimated from overnight home oximetry (ApneaLink monitor) used for obstructive sleep apnoea diagnosis. Cox proportional hazards models were used to determine associations of categorized sleep duration (<6 h, 6–8 h (reference), and >8 h) and major cardiovascular outcomes: primary composite of cardiovascular death, non-fatal myocardial infarction, non-fatal stroke, and any hospitalization for unstable angina, heart failure, or transient ischemic attack; secondary composite of cardiac and cerebral (stroke/transient ischemic attack) events.

Results

Oximetry-derived sleep duration estimates were available in 2687 participants (mean 61.2 years, 80.9% males) who experienced a total of 436 cardiovascular events over a mean follow-up of 3.7 years. Compared to the reference category, sleep duration was not associated with risk of the primary composite cardiovascular outcome (adjusted hazard ratio (HR) 1.00, 95% confidence interval 0.76–1.33, and HR 1.22, 95% confidence interval 0.98–1.52, for sleep duration <6 and >8 h, respectively). However, long sleep was associated with increased cerebral events (HR 1.67, 95% confidence interval 1.17–2.39; P = 0.005) and stroke alone (HR 1.79, 95% confidence interval 1.22–2.63; P = 0.003).

Conclusions

Long sleep duration is associated with an increased risk of stroke but not cardiac events in obstructive sleep apnoea patients with existing cardiovascular disease.

Clinical trial registration

The trial is registered at ClinicalTrials.gov (NCT00738179).

Interaction Between Slow Wave Sleep and Obstructive Sleep Apnea in Prevalent Hypertension

Due to frequent abnormal breathing events and their effects on sleep architecture, patients with obstructive sleep apnea (OSA) exhibit decreased amounts of slow wave sleep (SWS). Reduced SWS has been linked to hypertension in community-based studies. We sought to investigate whether SWS percentage modifies the association between OSA and prevalent hypertension. We studied 7107 patients with OSA and 1118 primary snorers who underwent in-laboratory polysomnography. Patients were classified into quartiles of percent SWS. Hypertension was defined based either on clinic blood pressure measures or on physician diagnosis. Multivariable logistic regression model showed a significant interaction effect of OSA and SWS on prevalent hypertension (P=0.002). Decreased SWS was associated with higher odds for hypertension in OSA but not in primary snoring, with patients with OSA exhibiting <0.1% SWS (OR, 1.44 [95% CI, 1.21-1.70]; P=0.001) and those with 0.1% to 4.8% SWS (OR, 1.20 [95% CI, 1.03-1.40]; P=0.02) being more likely to have hypertension compared with those with >11.1% SWS. In analysis stratified by OSA severity, significant associations between percent SWS and blood pressure emerged only in moderate and severe OSA. Effect modifications by sex (P=0.040) and age (P=0.007) were also only evident in OSA, indicating that decreased SWS was associated with hypertension only in men and in patients <60 years old. Decreased SWS is associated with a dose-dependent increase in odds of prevalent hypertension in patients with OSA. The effects of SWS are likely to be modulated by OSA severity. SWS may be implicated in the heightened risk of cardiovascular diseases exhibited by patients with OSA.

Sleep duration and health-related quality of life in Korean adults: 2007-2015 Korea National Health and Nutrition Examination Survey

PURPOSE

To evaluate the association of sleep duration with health-related quality of life (HRQOL) and examine the influence of age, sex, and common comorbidities on this association.

METHODS

Using appropriate survey design, we analyzed 50,181 adults who participated in the 2007-2015 Korea National Health and Nutrition Examination Survey. Participants were categorized into five groups according to self-reported sleep duration ≤ 5 (short sleeper), 6, 7, 8, and ≥ 9 h (long sleeper). HRQOL was measured with the European Quality of Life-5 Dimensions (EQ-5D) index and visual analogue scale (VAS).

RESULTS

In multiple linear regression, short sleep duration was associated with lower EQ-5D index (β = - 0.024; 95% confidence interval [CI], - 0.027 to - 0.021) and lower EQ-VAS (β = - 3.0; 95% CI, - 3.7 to - 2.3), and long sleep duration was associated with lower EQ-5D index (β = - 0.016; 95% CI, - 0.021 to - 0.011) and lower EQ-VAS (β = - 2.2; 95% CI, - 3.1 to - 1.3) compared with 7-h sleepers. Old-age (≥ 65 years old) short and long sleepers had significantly lower EQ-5D index than those of < 65 years old. When separated according to sex, men with long sleep and women with short sleep showed the lowest EQ-5D index. Short and long sleepers with hypertension, diabetes, hypercholesterolemia, cardiovascular disease, or depression showed significantly lower EQ-5D index than those without comorbidities.

CONCLUSIONS

Extreme sleep duration was associated with poor HRQOL. Short and long sleepers with old age and comorbidities had significantly lower HRQOL than those without such conditions.