Validity of the Berlin questionnaire in detecting obstructive sleep apnea: A systematic review and meta-analysis

Identifying the risk of obstructive sleep apnea in metabolic syndrome patients: Diagnostic accuracy of the Berlin Questionnaire

BACKGROUND

Obstructive sleep apnea (OSA) is a risk factor frequently present in patients with metabolic syndrome (MetS). Additionally, moderate and severe OSA are highly prevalent in patients with cardiac disease, as they increase the riskfor cardiovascular events by 80%. The gold standard diagnostic method for OSA is overnight polysomnography (PSG), which remains unaffordable for the overall population. The aim of the present study was to evaluate whether the Berlin Questionnaire (BQ) is anuseful tool for assessing the risk of OSA in patients with MetS.

METHODS

97 patients, previously untreated and recently diagnosed with MetS (National Cholesterol Education Program, Adult Treatment Panel III, ATP-III) underwent a PSG. OSA was characterized by the apnea-hypopnea index (AHI). BQ was administered before PSG and we evaluated sensitivity, specificity, positive and negative predictive values, and accuracy.

RESULTS

Of the 97 patients with MetS, 81 patients had OSA, with 47 (48.5%) presenting moderate and severe OSA. For all MetS with OSA (AHI≥5 events/hour), the BQ showed good sensitivity (0.65, 95% CI 0.54 to 0.76) and fair specificity (0.38, 95% CI 0.15-0.65) with a positive predictive value of 0.84, a negative predictive value of 0.18 and an 84% accuracy. Similarly, for moderate-to-severe OSA (AHI≥15 events/hour) we found good sensitivity (0.73, 95% CI 0.58-0.85) and fair specificity (0.40, 95% CI 0.27-0.55). Interestingly, for severe OSA (AHI≥30 events/hour), there was a very good sensitivity (0.91, 95% CI 0.72-0.99) and moderate specificity (0.42, 95% CI 0.31-0.54).

CONCLUSION

The BQ is a valid tool for screening the risk of OSA in MetS patients in general, and it is particularly useful in predicting severe OSA.

Sleepless in Beirut: Sleep Difficulties in an Urban Environment With Chronic Psychosocial Stress

STUDY OBJECTIVES

The prevalence of sleep disorders in the Lebanese population is unknown. We assessed the prevalence of insomnia and sleep apnea risk and examined their relationship with sociodemographic, lifestyle, and health characteristics in a sample from Greater Beirut.

METHODS

This cross-sectional pilot survey included 501 adults from the community (age 45.2 ± 15.2 years, 64% females). Insomnia symptoms, insomnia disorder, and sleep apnea risk were assessed using the Sleep Heart Health Study and Berlin Questionnaire. Characteristics were compared between individuals with and without insomnia symptoms, insomnia disorder, and sleep apnea. Correlates were assessed using multivariate regression.

RESULTS

A total of 44.5% of participants reported insomnia symptoms > 15 nights/mo and 34.5% reported insomnia. Predictors of insomnia symptoms and disorder included female sex (odds ratio [OR] 1.51, 95% confidence interval [CI] 1.01-2.27 and OR 1.76, 95% CI 1.13-2.75, respectively), education level below high school (OR 1.96, 95% CI 1.31-2.95 and OR 2.40, 95% CI 1.52-3.77, respectively) and medical comorbidities (OR 2.27, 95% CI 1.30-3.95 and OR 3.02, 95% CI 1.3-5.27, respectively). Although 31% of participants were at high risk for sleep apnea, only 5% received the diagnosis from a physician. Increased sleep apnea risk was associated with unemployment (OR 1.96, 95% CI 1.11-3.49), high body mass index (OR 1.17, 95% CI 1.11-1.24), snoring (OR 16.7, 95% CI 9.0-31.0), hypertension (OR 4.33, 95% CI 2.28-8.22), arthritis (OR 2.00, 95% CI 1.01-4.01), and other medical comorbidities (OR 2.65, 95% CI 1.24-5.68).

CONCLUSIONS

Insomnia and sleep apnea are highly prevalent and likely underdiagnosed in this cohort from Lebanon and are associated with disadvantaged socioeconomic status and medical comorbidities. This alarming prevalence of sleep difficulties and disorders calls for future research exploring the causes including the potential effect of social, economic, and political instability, mental and psychological stress, local customs, and environmental factors.

Use of Berlin questionnaire in comparison to polysomnography and home sleep study in patients with obstructive sleep apnea

Background

Obstructive sleep apnea syndrome (OSAS) is a common disorder with significant morbidity and mortality. We aimed to evaluate the predictive accuracy of the Berlin questionnaire in patients with suspected OSAS undergoing PSG in the sleep laboratory setting against those going through the Embletta™ portable diagnostic system (Embletta PDS) at home.

Methods

Patients with suspected OSAS were recruited from respiratory clinics to complete Berlin questionnaire and Epworth Sleepiness Score (ESS). Patients were randomized to undergo either home-based sleep test (group A) or hospital-based polysomnography (PSG) (group B).

Results

Three hundreds and sixteen subjects with newly referred suspected OSAS were recruited and randomized into group A (n = 157) and group B (n = 159). The prevalence of moderate to severe OSAS defined as apnea-hypopnea index (AHI) ≥ 15/h was 54%. The Berlin questionnaire identified 69.7% (n = 99) of subjects as high risk in group A and 77.5% (n = 100) in group B. The sensitivity, specificity, negative predictive value (NPV), and positive predictive value (PPV) of the questionnaire to predict an AHI ≥ 15/h as diagnosed by PSG was 78, 23, 67 and 35%. When compared with Embletta PDS, the specificity and NPV increased to 48 and 63%. The area under the Receiver Operator Curve (ROC) based on PSG (AUC = 0.539, 95%CI 0.417, 0.661) and based on home Embletta (AUC = 0.712, 95%CI 0.617, 0.907).

Conclusions

The questionnaire was not reliable in predicting OSAS through PSG AHI whereas there was some predictive ability in discriminating patients with OSAS from normal subjects based on home Embletta sleep test.

Trial registration

The study was registered at ClinicalTrials.gov (Identifier: NCT01828216) on 10 April 2013.

Serum biomarkers of inflammation and adiposity in the LABS cohort: associations with metabolic disease and surgical outcomes

BACKGROUND

The utility of serum biomarkers related to inflammation and adiposity as predictors of metabolic disease prevalence and outcomes after bariatric surgery are not well-defined.

METHODS

Associations between pre- and post-operative serum levels of four biomarkers (C-reactive protein (CRP), cystatin C (CC), leptin, and ghrelin) with baseline measures of adiposity and metabolic disease prevalence (asthma, diabetes, sleep apnea), and weight loss and metabolic disease remission after bariatric surgery were studied in the Longitudinal Assessment of Bariatric Surgery (LABS) cohort.

RESULTS

Baseline CRP levels were positively associated with the odds of asthma but not diabetes or sleep apnea; baseline CC levels were positively associated with asthma, diabetes, and sleep apnea; baseline leptin levels were positively associated with asthma and negatively associated with diabetes and sleep apnea; baseline ghrelin levels were negatively associated with diabetes and sleep apnea. Increased weight loss was associated with increased baseline levels of leptin and CRP and decreased baseline levels of CC. Remission of diabetes and asthma was not associated with baseline levels of any biomarker. A higher likelihood of asthma remission was associated with a greater decrease in leptin levels, and a higher likelihood of diabetes remission was predicted by a lesser decrease in CC. Bariatric surgery was associated with decreased post-operative CC, CRP, and leptin levels, and increased post-operative ghrelin levels.

CONCLUSION

This is the largest study to date of serum biomarkers of inflammation and adiposity in a bariatric surgery cohort. Biomarker levels correlate with metabolic disease prevalence prior to bariatric surgery, and with weight loss but not metabolic disease remission after surgery. Bariatric surgery regulates serum biomarker levels in a manner consistent with anti-inflammatory and compensatory orexigenic effects. These data contribute to our understanding of the mechanisms underlying the biologic effects of bariatric surgery.

Evaluation of sleep quality and risk of obstructive sleep apnea in patients referred for aesthetic rhinoplasty

Importance

Aesthetic rhinoplasty is the fifth surgical procedure most performed worldwide by plastic surgeons. With the growing demand for rhinoplasty, there is an unmet need for research into the profile of patients who seek aesthetic nasal surgery in an attempt to improve not only cosmetic dissatisfactions, but also the manifestations of other, possibly interrelated disorders, especially sleep disturbances.

Objective

To evaluate the sleep quality and the risk of Obstructive Sleep Apnea in patients referred for aesthetic rhinoplasty, as well as the association of these conditions with nasal symptoms. Design: Cross-sectional study performed at the period of June/2016 to August/2017. Setting: Department of Otolaryngology and Head and Neck Surgery - Universidade Federal de São Paulo. Participants: Patients of both sexes, aged 18 to 65 years, who were referred for aesthetic rhinoplasty. We evaluated 46 patients, two of whom were excluded because they were outside the inclusion age criteria. Main Outcome(s) and Measure(s): Anterior rhinoscopy and the following validated surveys were used. Pittsburgh Sleep Quality Index; Epworth Sleepiness Scale; Nasal Obstruction Symptom Evaluation scale; Berlin Questionnaire. The visual analog scale for snoring was also used.

Results

Of the 44 participants, 18 (41%) were males and 26 (59%) were females. 82% had poor sleep quality. 46% presented excessive daytime sleepiness. There was a high risk for Obstructive Sleep Apnea in 27%. Regarding to nasal symptoms, the mean score in the Nasal Obstructive Symptoms Evaluation was 66.25±25.38. When comparing the groups with good and poor sleep quality, we observed a higher risk for Obstructive Sleep Apnea (p=0.05) in patients with poor sleep quality. Patients at high risk for Obstructive Sleep Apnea had higher scores on the Nasal Obstructive Symptoms Evaluation (p=0.001) and on the analogue snoring scale (p<0.001) compared to patients at low risk.

Conclusions

We observed a high occurrence of poor sleep quality in participants. All participants who were at high risk for obstructive sleep apnea were also classified as having poor sleep quality. An association was also observed between the presence of high risk for obstructive sleep apnea and presence of nasal symptoms.

Sleep Disorders Among People With Migraine: Results From the Chronic Migraine Epidemiology and Outcomes (CaMEO) Study

OBJECTIVES

We examined the cross-sectional association of sleep apnea and indices of sleep quality with both episodic migraine (EM) and chronic migraine (CM).

BACKGROUND

Sleep apnea and abnormal patterns of sleep, such as insomnia, were associated with migraine onset, severity, and progression in previous research.

METHODS

The Chronic Migraine Epidemiology & Outcomes Study, a longitudinal study, used a series of web-based surveys to assess migraine symptoms, burden, and patterns of health care utilization. Quota sampling was used from September 2012 to November 2013 to generate a representative sample of the US population. Persons who screened positive for sleep apnea on the Berlin Questionnaire are said to be at "high risk" for sleep apnea. Respondents indicated if they believed that they had sleep apnea, if a physician had diagnosed it, and if and how they were treated. Other aspects of sleep quality were assessed using the Medical Outcomes Study (MOS) Sleep Measures.

RESULTS

Of 12,810 eligible respondents with migraine and data on sleep, 11,699 with EM (91.3%) and 1111 with CM (8.7%) provided valid data for this analyses. According to the Berlin Questionnaire, 4739/12,810 (37.0%) were at "high risk" for sleep apnea, particularly persons with CM vs EM (575/1111 [51.8%] vs 4164/11,699 [35.6%]), men vs women (1431/3220 [44.4%] vs 3308/9590 [34.5%]), people with higher body mass index, and older people (all P < .001). Among respondents to the MOS Sleep Measures, persons with CM were more likely to report poor sleep quality than those with EM, including sleep disturbance (mean [SD] values: 53.2 [26.9] vs 37.9 [24.3]), snoring (38.0 [33.9] vs 31.0 [32.1]), shortness of breath (34.9 [29.8] vs 15.3 [20.6]), somnolence (44.1 [23.4] vs 32.2 [21.2]), and less likely to report sleep adequacy (34.0 [24.2] vs 39.2 [22.1]).

CONCLUSIONS

Compared with respondents with EM, a larger proportion of those with CM were at "high risk" for sleep apnea and reported poor sleep quality. This reflects an association between CM vs EM and sleep apnea and poor sleep quality; the potential relationships are discussed.

Differentiation of adult severe asthma from difficult-to-treat asthma - Outcomes of a systematic assessment protocol

BACKGROUND

Guidelines recommend a differentiation of difficult-to-treat asthma from severe asthma. However, this might be complex and to which extent this distinction is achievable in clinical practice remains unknown.

OBJECTIVE

To evaluate to which degree a systematic evaluation protocol enables a differentiation between severe versus difficult-to-treat asthma in patients in specialist care on high intensity asthma treatment, i.e. potentially severe asthma.

METHODS

All adult asthma patients seen in four respiratory clinics over one year were screened prospectively for asthma severity. Patients with difficult-to-control asthma according to ERS/ATS criteria (high-dose inhaled corticosteroids/oral corticosteroids) underwent systematic assessment to differentiate severe asthma patients from those with other causes of poor asthma control: objective confirmation of the asthma diagnosis as well as assessment of treatment barriers and comorbidities.

RESULTS

Overall, 1034 asthma patients were screened, of whom 175 (16.9%) had difficult-to-control asthma. 117 of these accepted inclusion, and completed systematic assessment. Asthma diagnosis was objectively confirmed in 88%. Sub-optimal adherence (42.5%), inhaler errors (31.5%) and unmanaged comorbidities (66.7%) were common. After primary assessment, 12% (14/117) fulfilled strict criteria for severe asthma. Moreover, 56% (66/117) were instantly classified as difficult-to-treat asthma due to poor adherence/inhaler technique. Finally, an ´overlap' group of 32% (37/117) were identified with patients being adherent and displaying correct inhaler technique, but had unmanaged comorbidities -potentially fitting into both the difficult-to-treat and severe group.

CONCLUSION

Only a minority of patients with difficult-to-control asthma were found to have severe asthma after primary systematic assessment. Nevertheless, strict categorisation of severe vs. difficult-to-treat asthma seems to pose a challenge.

Race, Sex, Age, and Regional Differences in the Association of Obstructive Sleep Apnea With Atrial Fibrillation: Reasons for Geographic and Racial Differences in Stroke Study

STUDY OBJECTIVES

To examine the cross-sectional association between obstructive sleep apnea (OSA) risk and atrial fibrillation (AF) in the REasons for Geographic And Racial Differences in Stroke (REGARDS), a cohort of black and white adults.

METHODS

Using REGARDS data from subjects recruited between 2003-2007, we assessed 20,351 participants for OSA status. High OSA risk was determined if the participant met at least two criteria from the Berlin Sleep Questionnaire (persistent snoring, frequent sleepiness, high blood pressure, or obesity). AF was defined as a self-reported history of a previous physician diagnosis or presence of AF on electrocardiogram. Logistic regression was used to determine odds ratio and 95% confidence interval for the association between OSA status and AF with subgroup analysis to examine effect modification by age, race, sex, and geographical region.

RESULTS

The prevalence of AF was 7% (n = 1,079/14,992) and 9% (n = 482/5,359) in participants at low and high risk of OSA, respectively (P < .0001). Persons at high risk of OSA had greater prevalence of diabetes and stroke history, and were more likely to be obese and taking sleep medications. In a multivariable analysis adjusted for demographics, cardiovascular risk factors, and potential confounders, high risk for OSA was associated with an increased odds of AF compared to low risk for OSA (odds ratio = 1.27, 95% confidence interval = 1.13, 1.44). This association differed significantly only by race (P for interaction = .0003). For blacks, there was a significant 58% increase in odds of AF in participants at high risk versus low risk of OSA, compared to a nonsignificant 12% increase in odds in whites. We were limited by self-reported variables, inability to adjust for obesity, and the cross-sectional nature of our study.

CONCLUSIONS

High risk of OSA is associated with prevalent AF among blacks but not whites.

COMMENTARY

A commentary on this article appears in this issue on page 1459.

The symptoms and risk of sleep apnea among adults in the United Arab Emirates

INTRODUCTION:

Recently, sleeping disorders and snoring are being recognized as a public health concern with various risk factors and health consequences. The main objective of the present study was to determine the prevalence of snoring and sleep apnea among adults (20–60 years) in Sharjah (United Arab Emirates, UAE) and assess the major risk factors as well as the general knowledge among the population.

METHODS:

A self-administrated Questionnaire of five sections including both Berlin questionnaire (BQ) and the Epworth Sleepiness Scales (ESS) were given to a randomly selected population in Sharjah between the ages of 20–60 years. Data were analyzed using SPSS software version 22.0.

RESULTS:

Nearly 34.2% of the study population reported to be snorers, and 43.2% of snorers were at high risk of sleep apnea based on the BQ. Gender was significantly associated with snoring (P = 0.038), as 40.8% of males reported snoring compared to 28.7% of females. Elderlies (50–60 years) were at a higher risk, and obesity (body mass index >30) was considered to be a powerful risk factor as 46.8% of the obese participants reported snoring. Those who scored higher on the ESS were more likely to be snorers (P = 0.001) and were likely to fall into the high-risk category in the BQ (P = 0.007). In addition, smoking (P = 0.005), hypertension (P = 0.005), and nasal septal deviation (P = 0.024) were also considered as risk factors.

CONCLUSION:

Prevalence and major risk factors within the UAE are similar to those in other countries. Sleeping disorders and snoring campaigns and management facilities should be considered to raise the awareness about these issues and manage their risk factors.

Sleep and Migraine: Assessment and Treatment of Comorbid Sleep Disorders

The relationship of sleep and migraine is unequivocal and familiarity with the nature and magnitude of these associations may inform clinical practice. Recent prospective, longitudinal, and time-series analysis has begun to unravel the magnitude and temporal patterns of sleep and migraine. Prospective evidence has shown that sleep variables can trigger acute migraine, precede and predict new onset headache by several years, and indeed, sleep disturbance and snoring are risk factors for chronification. The presence of a sleep disorder is associated with more frequent and severe migraine and portends a poorer headache prognosis. Interestingly, the disorders linked to migraine are quite varied, including insomnia, snoring and obstructive sleep apnea, restless legs, circadian rhythm disorders, narcolepsy, and others. Insomnia is by far the most common sleep disorder in headache patients. In fact, the majority of patients with chronic migraine presenting for treatment have insomnia. Despite a rapidly expanding literature, very few controlled treatment studies have been published to guide clinical practice. This paper focuses on clinical assessment and treatment of sleep disorders. An algorithm is presented for sleep disorders management in the migraine patient, which highlights major sleep disorders and psychiatric comorbidity. Diagnostic procedures are recommended that are conducive to clinical practice. Suggested tools include the sleep history, screening mnemonics, prediction equation, and sleep diary. New developments in treatment have produced abbreviated and cost-effective therapies for insomnia and obstructive sleep apnea that may reach a larger population. Revisions in the diagnostic manuals for sleep and headache disorders enhance recognition of sleep-related headache. Recommendations include behavioral sleep regulation, shown in recent controlled trials to decrease migraine frequency, management for sleep apnea headache, cognitive behavioral therapy (CBT) for insomnia abbreviated for the physician practice setting, sleep-related headache trigger, and others. There is no empirical evidence that sleep evaluation should delay or supersede usual headache care. Rather, sleep management is complimentary to standard headache practice.

A Novel Artificial Neural Network Based Sleep-Disordered Breathing Screening Tool

STUDY OBJECTIVES

This study evaluated a novel artificial neural network (ANN) based sleep-disordered breathing (SDB) screening tool incorporating nocturnal pulse oximetry with demographic, anatomic, and clinical data. The tool was compatible with 6 categories of apnea-hypopnea index (AHI) with 4% oxyhemoglobin desaturation threshold, ≥ 5, 10, 15, 20, 25, and 30 events/h.

METHODS

Using a general population dataset, the training set included 2,280 subjects, whereas the test set included 470 subjects. The input of this tool was a set of 22 variables. The tool had six neural network models for each AHI threshold. Several metrics were explored to evaluate the performance of the tool: area under the receiver operating characteristic curve (AUC), sensitivity, specificity, positive predictive value, negative predictive value, and 95% confidence interval (CI).

RESULTS

The AUC was 0.904, 0.912, 0.913, 0.926, 0.930, and 0.954, respectively, with models of AHI ≥ 5, 10, 15, 20, 25, and 30 events/h thresholds. The sensitivities of all neural network models were higher than 95%. The AHI ≥ 30 events/h model had the maximum sensitivity: 98.31% (95% CI: 95.01%-100%).

CONCLUSIONS

The results of this study suggested that the ANN based SDB screening tool can be used to identify the presence or absence of SDB. Future validation should be performed in other populations to determine the practicability of this screening tool in sleep clinics and other at-risk populations.

A Review of Scales to Evaluate Sleep Disturbances in Movement Disorders

Patients with movement disorders have a high prevalence of sleep disturbances that can be classified as (1) nocturnal sleep symptoms, such as insomnia, nocturia, restless legs syndrome (RLS), periodic limb movements (PLM), obstructive sleep apnea (OSA), and REM sleep behavior disorder; and (2) diurnal problems that include excessive daytime sleepiness (EDS) and sleep attacks. The objective of this review is to provide a practical overview of the most relevant scales that assess these disturbances to guide the choice of the most useful instrument/s depending on the line of research or clinical focus. For each scale, the reader will find a brief description of practicalities and psychometric properties, use in movement disorder cohorts and analyzed strengths and limitations. To assess insomnia, the Pittsburgh Sleep Quality Index, a generic scale, and three disease-specific scales: the Parkinson Disease Sleep Scale (PDSS), the PDSS-2, and Scales for outcomes in Parkinson's disease (PD)-Sleep-Nocturnal Sleep subscale are discussed. To evaluate nocturia, there are no specific tools, but some extensively validated generic urinary symptom scales (the Overall Bladder Questionnaire and the Overactive Bladder Symptom Score) and some PD-specific scales that include a nocturia item are available. To measure RLS severity, there are currently four domain-specific generic scales: The International Restless Legs Scale, the Johns Hopkins Restless Legs Severity Scale, the Restless Legs Syndrome-6 measure, a Pediatric RLS Severity Scale, and the Augmentation Severity Rating Scale (a scale to evaluate augmentation under treatment) and several instruments that assess impact on quality of sleep and health-related quality of life. To evaluate the presence of PLM, no clinical scales have been developed to date. As far as OSA, commonly used instruments such as the Sleep Apnea Scale of the Sleep Disorders Questionnaire, the STOP-Bang questionnaire, and the Berlin Questionnaire are reviewed. Three scales have been extensively used to assess EDS: the generic Epworth Sleepiness Scale, the Stanford Sleepiness Scale, and the PD-specific Scales for outcomes in PD-Sleep-Daytime sleepiness subscale. To date, only the Inappropriate Sleep Composite Score specifically evaluates propensity to sleep attacks.

The association of snoring and risk of obstructive sleep apnea with poor academic performance among university students

STUDY OBJECTIVES

Subjects with obstructive sleep apnea (OSA) have neurocognitive dysfunction. The aim of this study was to estimate the prevalence of symptoms and risk of OSA among university students and the association with academic performance.

METHODS

A cross-sectional study was conducted at Jordan University of Science and Technology. Students from faculties of engineering, medicine, nursing, pharmacy, and dentistry were asked to participate in this study. The Berlin Sleep Questionnaire was used to report symptoms and risk of OSA. Below average cumulative scores were considered poor academic performance.

RESULTS

A total of 777 students (51% female; mean age, 20 years) completed the study questionnaire. According to the study definition, 42 students (5.4%) had high risk for OSA. Snoring was reported by 11% and daytime sleepiness and fatigue by 30%. Compared to female students, male students had more snoring (14.6 vs. 7.6%, p = 0.002) and higher risk for OSA (6.5 vs. 1.6%, p = 0.001). Both self-reported snoring and being at high risk for OSA were associated with poor academic performance (27.9 vs. 11.6% and 23.1 vs. 9.2%, respectively; p < 0.02). After adjusting for confounding factors, the odds ratio of having poor academic performance in students at high risk for OSA was 2.4 (CI 1.11-5.2, p = 0.027).

CONCLUSIONS

Snoring and OSA were uncommon among university students. However, both were more common among male students and were associated with poor academic performance.

Short Sleep Duration, Obstructive Sleep Apnea, Shiftwork, and the Risk of Adverse Cardiovascular Events in Patients After an Acute Coronary Syndrome

BACKGROUND

It is unknown whether short sleep duration, obstructive sleep apnea, and overnight shift work are associated with the risk of recurrent cardiovascular events in patients after an acute coronary syndrome.

METHODS AND RESULTS

SOLID-TIMI 52 (The Stabilization of PLaques UsIng Darapladib-Thrombolysis in Myocardial Infarction 52 Trial) was a multinational, double-blind, placebo-controlled trial that enrolled 13 026 patients ≤30 days of acute coronary syndrome. At baseline, all patients were to complete the Berlin questionnaire to assess risk of obstructive sleep apnea and a sleep and shift work survey. Median follow-up was 2.5 years. The primary outcome was major coronary events (MCE; coronary heart disease death, myocardial infarction, or urgent revascularization). Cox models were adjusted for clinical predictors. Patients who reported <6 hours sleep per night had a 29% higher risk of MCE (adjusted hazard ratio, 1.29; 95% confidence interval, 1.12-1.49; P<0.001) compared with those with longer sleep. Patients who screened positive for obstructive sleep apnea had a 12% higher risk of MCE (1.12; 1.00-1.24; P=0.04) than those who did not screen positive. Overnight shift work (≥3 night shifts/week for ≥1 year) was associated with a 15% higher risk of MCE (1.15; 1.03-1.29; P=0.01). A step-wise increase in cardiovascular risk was observed for individuals with more than 1 sleep-related risk factor. Individuals with all 3 sleep-related risk factors had a 2-fold higher risk of MCE (2.01; 1.49-2.71; P<0.0001).

CONCLUSIONS

Short sleep duration, obstructive sleep apnea, and overnight shift work are under-recognized as predictors of adverse outcomes after acute coronary syndrome. Increased efforts should be made to identify, treat, and educate patients about the importance of sleep for the potential prevention of cardiovascular events.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT01000727.