Mortality in sleep apnea patients: a multivariate analysis of risk factors

Prevalence and related factors for high-risk of obstructive sleep apnea in a large korean population: results of a questionnaire-based study

Background and Purpose

A population-based door-to-door study of cross-sectional methods for assessing the prevalence and factors related to a high risk of obstructive sleep apnea (OSA) was conducted using the Korean version of the Berlin Questionnaire (K-BQ).

Methods

Pooled data collected from Community Health Surveys by the Korea Center for Disease Control and Prevention were analyzed. Of 8,140 respondents from the population, 7,955 were finally included in this study.

Results

Of the 7,955 included subjects, 15.7% of the men and 9.8% of the women were at high risk of OSA. Significant differences were found in the following factors between the subjects with a high risk of OSA: gender, age, marital status, educational level, occupation, and presence of smoking, harmful alcohol use, and chronic diseases. Male sex, harmful alcohol use, and the presence of chronic diseases were identified as factors independently associated with a high risk of OSA.

Conclusions

This is the first study to confirm the usefulness of the K-BQ to study the prevalence of OSA in the Korean general population. The findings demonstrate that harmful alcohol use and chronic diseases are very common characteristics among those with a high risk of OSA.

Neural control of the upper airway: integrative physiological mechanisms and relevance for sleep disordered breathing

The various neural mechanisms affecting the control of the upper airway muscles are discussed in this review, with particular emphasis on structure-function relationships and integrative physiological motor-control processes. Particular foci of attention include the respiratory function of the upper airway muscles, and the various reflex mechanisms underlying their control, specifically the reflex responses to changes in airway pressure, reflexes from pulmonary receptors, chemoreceptor and baroreceptor reflexes, and postural effects on upper airway motor control. This article also addresses the determinants of upper airway collapsibility and the influence of neural drive to the upper airway muscles, and the influence of common drugs such as ethanol, sedative hypnotics, and opioids on upper airway motor control. In addition to an examination of these basic physiological mechanisms, consideration is given throughout this review as to how these mechanisms relate to integrative function in the intact normal upper airway in wakefulness and sleep, and how they may be involved in the pathogenesis of clinical problems such obstructive sleep apnea hypopnea.

Sleep disordered breathing in primary care medicine

Primary care medicine plays a key role in the delivery of health care. Sleep disorders medicine is a new specialty and standard medical school curricula do not contain any or only very little training in sleep medicine. Unrecognized and therefore untreated sleep disorders account for a large loss of human life and socio-economic damage. Recognition of sleep disorders, in particular sleep-disordered breathing at the primary care level is thus a major element in health care delivery. The objective of this study was to assess the occurrence of the risk of sleep-disordered breathing (SDB) in a large primary care population. 852 primary care patients received a validated questionnaire which contained items based on signs and symptoms of SDB, periodic limb movement disorder (PLMD), and insomnia. A polygraphically validated algorithm was used to identify patients with a high suspicion of having sleep disordered breathing. Based on this algorithm 20% of the study participants had a high risk for SDB, 18.5% of PLMD and 25% of insomnia.Most commonly daytime sleepiness and fatigue was associated in patients with a positive likelihood of SDB, PLMD, and insomnia. Fifty percent of all primary care patients reported to snore while 31% of snorers reported to snore every night. SDB was twice as common in men than in women and associated with a significantly higher body mass index. A popular validated scale to assess the degree of daytime sleepiness, the Epworth sleepiness scale, was not always useful to document the degree of daytime sleepiness.We conclude that SDB, PLMD, and insomnia are very frequent sleep disorders in primary care patients yielding the need to include assessment of these sleep disorders in the medical history of primary care physicians.

New therapeutics in promoting and modulating mandibular growth in cases with mandibular hypoplasia

Children with mandibular growth deficiency may develop airway obstruction. The standard treatment of severe airway obstruction involves invasive procedures such as tracheostomy. Mandibular distraction osteogenesis has been proposed in neonates with mandibular deficiency as a treatment option to avoid tracheostomy procedure later in life. Both tracheostomy and distraction osteogenesis procedures suffer from substantial shortcomings including scarring, unpredictability, and surgical complications. Forward jaw positioning appliances have been also used to enhance mandible growth. However, the effectiveness of these appliances is limited and lacks predictability. Current and future approaches to enhance mandibular growth, both experimental and clinical trials, and their effectiveness are presented and discussed.

Intima-media thickness in patients with obstructive sleep apnea without comorbidities

Background

Obstructive sleep apnea (OSA) is associated with elevated risk of cardiovascular events. The early stages of vascular complications can be visualized by means of ultrasound. Intima-media thickness (IMT) correlates with the presence of risk factors of cardiovascular diseases such as hypertension, diabetes, tobacco smoking, or hyperlipidemia. However, little is known whether OSA itself may be the cause of IMT thickening.

Methods

The study group was composed of 28 patients (6 women, 22 men; mean age = 53.8 years, mean BMI = 27.1 kg/m², mean AHI = 22.4/h) with OSA who had no comorbidities. The control group consisted of 28 healthy subjects (6 women, 22 men; mean age = 53.9 years; mean BMI = 27.5 kg/m²). In both groups IMT was assessed in common carotid arteries with the use of ultrasonography. Additionally, in patients with OSA, pulse wave velocity, echocardiography, 24-h automated blood pressure monitoring, clinical signs and symptoms, and blood tests were performed to investigate possible correlations with IMT.

Results

Median IMT was 0.41 mm in OSA patients and 0.46 mm in the control group (p = 0.087). Echocardiography revealed left ventricle hypertrophy in 21 %, systolic disorders in 8 %, and diastolic disorders in 57 % of the patients. In a large majority of patients, pulse wave velocity was found to be normal. IMT correlated with age (r = 0.446, p = 0.017), total cholesterol (r = 0.518, p = 0.005), daytime systolic blood pressure (r = 0.422, p = 0.025), pulse pressure 24 h and daytime (r = 0.424, p = 0.027 and r = 0.449, p = 0.019), early mitral flow/atrial mitral flow (E/A) (r = −0.429, p = 0.023), and posterior wall diameter (PWD) (r = 0.417, p = 0.270).

Conclusion

In a relatively nonobese group of patients, no significant differences were found in the intima-media thickness between OSA patients without concomitant cardiovascular diseases and healthy controls. This may lead to the conclusion that IMT does not reflect increased risk of cardiovascular events in patients with isolated OSA.

Severe obstructive sleep apnea increases mortality in patients with ischemic heart disease and myocardial injury

OBJECTIVES

We hypothesized that obstructive sleep apnea(OSA) has a dose-dependent impact on mortality in those with ischemic heart disease or previous myocardial injury.

METHODS

We performed a retrospective cohort study of 281 consecutive OSA patients with a history of myocardial injury as determined by elevated troponin levels or with known existing ischemic heart disease. We compared survival between those with severe OSA [apnea–hypopneaindex (AHI) ≥30] and those with mild to moderate OSA(AHI >5 and <30).

RESULTS

Of the 281 patients (mean age 65 years, mean BMI34, 98% male, 58% with diabetes), 151 patients had mild moderate OSA and 130 had severe OSA. During a mean follow-up of 4.1 years, there were significantly greater deaths in the severe OSA group compared to the mild moderate OSA group [53 deaths (41%) vs. 44 deaths(29%), respectively, p00.04]. The adjusted hazard ratio for mortality with severe OSA was 1.72 (95% confidence interval1.01–2.91, p00.04).

CONCLUSIONS

The severity of obstructive sleep apnea is associated with increased risk of death, and risk stratification based on OSA severity is relevant even in the diseased cardiac patient.

Obstructive sleep apnea after radial forearm free flap reconstruction of the oral tongue

OBJECTIVES/HYPOTHESIS

To determine whether radial forearm free flap reconstruction of the tongue after partial glossectomy is associated with obstructive sleep apnea.

STUDY DESIGN

Retrospective case series.

METHODS

Fifteen patients (5 men, 10 women) treated for tongue cancer in 2006-2010 by partial glossectomy and immediate radial forearm free flap reconstruction completed the Epworth Sleepiness Scale and underwent polysomnographic studies. Background, clinical, and pathologic data were collected from the medical files.

RESULTS

Mean ± SD age of the study group was 57 ± 19 years; body mass index, 24 ± 4; follow-up, 5.6 ± 2.8 years. Mean ± SD Epworth scale score was 8.18 ± 6.18 (normal, <8). Disordered sleep was documented in 11 patients, of whom 8 (53.3% of the cohort) had OSA (5 mild, 2 moderate, 1 severe). The OSA rate was significantly higher than reported in the general population (P = 0.001).

CONCLUSION

Patients after partial glossectomy and radial forearm free flap reconstruction appear to be at high risk of obstructive sleep apnea. Testing for OSA should be considered in these patients.

Relation of central fat mass to obstructive sleep apnea in the elderly

STUDY OBJECTIVES

Obesity is a recognized risk factor for obstructive sleep apnea syndrome (OSAS). We evaluated whether total trunk and central fat mass (CFM) is associated with OSAS in elderly subjects.

DESIGN

Cross-sectional.

SETTING

Body composition assessment by dual-energy X-ray absorbsiometry (DEXA).

PARTICIPANTS

749 volunteers aged 67.2 ± 0.8 years (59.4% women).

INTERVENTION

All participants underwent evaluation of their body composition by DEXA in parallel with clinical and polygraphic assessments. The presence of OSAS was defined by an apnea plus hypopnea index (AHI) ≥ 15.

MEASUREMENTS AND RESULTS

A total of 44.8% of the population had an AHI < 15, and 55.2% presented OSAS. OSAS subjects were more frequently overweight and had a higher total trunk fat mass and central fat mass (CFM). Correlation analyses revealed that body mass index (r = 0.27, P < 0.001), neck circumference (r = 0.35, P < 0.001), and CFM (r = 0.23, P < 0.001) were significantly related to AHI. Logistic regression analysis indicated that in mild OSAS cases (> 15AHI < 30), BMI (OR: 1.10; 95% CI: 1.03-1.18; P = 0.008), and male gender (OR: 1.49; 95% CI: 1.05-2.12, P = 0.03) were key factors explaining an AHI between 15 and 30. In severe cases (AHI > 30), male gender (OR: 3.65; 95% CI: 2.40-5.55; P < 0.001) and CFM (OR: 1.10; 95% CI: 1.03-1.19; P = 0.009) were significant independent predictors of OSAS.

CLINICAL TRIAL REGISTRATION

NCT 00759304 and NCT 00766584.

CONCLUSIONS

Although central fat mass plays a role in the occurrence of severe OSAS in men older than 65 years of age, its low discriminative sensitivity in mild OSAS cases does not warrant systematic use of DEXA for the diagnosis of OSAS.

The utility of routine EEG in the diagnosis of sleep disordered breathing

Sleep disordered breathing (SDB) is a common medical condition. Its manifestations of snoring, nocturnal choking, arousals, and sleep fragmentation can lead to excessive daytime sleepiness, neuropsychological slowing, lapses of consciousness, and accidents that can be misinterpreted as epileptic phenomena. Moreover, patients with documented epilepsy commonly exhibit similar symptomatology because of the undiagnosed coexistence of sleep apnea. Therefore, a large proportion of patients referred to the electroencephalogram (EEG) laboratory primarily to confirm or refute the diagnosis of epilepsy could suffer from latent sleep apnea and the routine EEG has the potential to divulge it. We retrospectively evaluated the reporting of sleep apnea symptomatology (snoring, choking, gasping/deep breath, apnea, desaturation, excessive drowsiness) in routine inpatient and outpatient adult EEG studies performed in our institution over the past 12 years (39,130 studies, approximately half of which recorded at least early stages of sleep). Comparisons were performed with the medical records to ascertain the coexistence of objectively diagnosed SDB with polysomnography before or after the EEG study and the importance of reporting variations in assisting with the diagnosis. Two illustrative examples are provided. Sixty-nine EEG studies were identified, performed primarily to confirm, or refute the diagnosis of epilepsy. The mean age of the subjects at EEG was 64 years (range 30-89), and 55 (80%) were male. 36% of them suffered from known epilepsy. Snoring was the most commonly reported sign in 48 (70%) of the studies, followed by arousals in 29 (42%), apnea in 16 (23%), excessive drowsiness in 13 (19%), gasping/deep breath in 9 (13%), and desaturation in 7 (10%). A sleep disorder was suggested in 25 (36%) of the interpretations and a direct recommendation for a sleep study was made in 22 of them (32%). This interpretation was included in the impression of the report in 21 (30%) of the cases, in the detail in 20 (30%) of the cases and in both in 28 (40%). Only 14 (20%) patients underwent polysomnography, and all of them were formally diagnosed with SDB. Seven (50%) of them were diagnosed with obstructive sleep apnea, 2 (14%) with central sleep apnea, 3 (22%) with both, 1 (7%) with upper airways resistance syndrome, and 1 (7%) with primary snoring. From these 14 patients, 9 (64%) were diagnosed with a sleep study performed after the EEG, 4 (29%) before the EEG interpretation, and 1 (7%) had a repeat study after the EEG. In the logistic regression model applied, with the exception of the presence of arousals (odds ratio = 4.63, P = 0.033), none of the aforementioned symptomatology or the reporting of suspicion for SDB or the location (impression vs. detail) of the reporting showed a statistically significant association with the completion of a sleep study. Routine EEG offers a unique opportunity of direct clinical observation along with electrophysiologic and cardiorespiratory monitoring. When sleep is recorded, it can help identify clinical and electrographic features of sleep apnea and prompt confirmation with a polysomnogram in the appropriate clinical context. It can therefore serve as a valuable, adjunctive tool for the diagnosis of SDB. Our data highlight that potential but unveil its decreased use in the neurology community. Increased awareness is required by the EEG technologists, interpreting neurologists, and referring physicians, regarding reporting and using sleep apnea features on the EEG.

An overnight increase in CO2 predicts mortality in sleep disordered breathing

BACKGROUND AND OBJECTIVE

Sleep disordered breathing (SDB) is highly prevalent but under-recognized. Evidence is accumulating for its role as a predictor of mortality independent of cardiovascular risk factors. The role of hypercapnia in SDB is not known systematically, and between 11 and 43% of patients with SDB develop chronic hypercapnia. Hypercapnia predicts mortality in other respiratory conditions. The role of hypercapnia in independently predicting mortality in patients with SDB after assessing for the presence of airways disease and obesity was investigated.

METHODS

The records of 396 consecutive patients were examined retrospectively. Univariate and multivariate analyses were performed using Cox proportional hazards regression to determine the association between gas exchange and polysomnography (PSG) variables and all-cause mortality, adjusted for potential confounders, including age, gender and presence of co-morbidity and airways disease.

RESULTS

The mean age of our patient population was 55 ± 15 years, and the mean body mass index (BMI) was 30.6 ± 6.2 kg/m2 . Out of the 322 patient population, 258 were men. After 10 years, 25% had died, following a maximum follow-up of 16.7 years. Mortality among patients with SDB was predicted by a difference between evening and morning PaCO2 (ΔPaCO2 ) of ≥7 mm Hg and evening hypoxaemia (PaO2 < 65 mm Hg), independent of age and the presence of co-morbidity and airways disease. There was a significant correlation between minimum oxygen saturation (SpO2 ) and ΔPaCO2  ≥ 7 mm Hg (P = 0.002) and evening PaO2 < 65 mm Hg (P < 0.001).

CONCLUSIONS

An overnight increase in CO2 and evening hypoxaemia are independent mortality predictors in SDB. A low minimum SpO2 identifies patients in whom morning and evening arterial blood gases are beneficial.

Comorbidities and survival in obstructive sleep apnoea beyond the age of 50

BACKGROUND

Although mortality risk associated with obstructive sleep apnoea (OSA) tends to disappear from the age of 50, it has been suggested that OSA treatment by continuous positive airway pressure (CPAP) improves survival even in older subjects. Life expectancy of subjects with several diseases is worse if OSA coexists. The objectives of this study were to evaluate the relevance of comorbidities in the relationship between OSA and mortality, and in the effect of CPAP on survival, in subjects ≥ 50 years old.

METHODS

Data from 810 patients studied by polysomnography for suspected OSA between 1991 and 2000 were retrospectively evaluated. In 2009, state of survival and use of CPAP were enquired. Three hundred and thirteen subjects were < 50 and 497 were ≥ 50 years at diagnosis.

RESULTS

Age and comorbidities, but not apnoea/hypopnoea index (AHI) or lowest nocturnal arterial oxygen saturation (Nadir SaO(2)), predicted mortality in the whole sample. Nadir SaO(2) was related to mortality among the younger subjects without comorbidities (P = 0·01), but not among the older subjects. In the older patients with an AHI > 30 CPAP treatment was associated with a better survival only if comorbidities coexisted.

CONCLUSIONS

Unlike in younger subjects, in subjects ≥ 50 years old, comorbidities do not mask an effect of OSA on mortality. Among OSA subjects ≥ 50 years old, comorbidities could separate those who may expect an improvement in survival with CPAP treatment from those who may not. Possibly, after the age of 50, OSA per se does not affect survival, but worsens prognosis of subjects with coexisting diseases.

Sleep apnea and atrial fibrillation; 2012 update

Atrial fibrillation (AF) and obstructive sleep apnea (OSA) are very prevalent diseases in modern society. Recent years have seen the emergence of a wide body of literature suggesting an important association between these two diseases. This review will provide a summary of this evidence as it currently exists. First, it will review the literature suggesting an association between AF and OSA by highlighting the prevalence of AF in OSA, the correlation of AF prevalence with OSA severity and the trend towards increased AF recurrence in patients with OSA after treatment for AF. Second, it will identify the possible pathophysiologic mechanisms for this association. In doing so, it will discuss the investigated effects of intrathoracic pressure changes, autonomic instability and atrial remodeling. Finally, it will review the evidence of the effect of treatment of OSA on AF, highlighting the role of continuous positive airway pressure (CPAP) in the treatment of OSA and its impact on AF prevalence and recurrence.

Indication of CPAP in Patients with Suspected Obstructive Sleep Apnea, Based on Clinical Parameters and a Novel Two-Channel Recording Device (ApneaLink): A Pilot Study

Objective. To evaluate the accuracy and reliability of the medical decision based on the results of the hand scoring from a two-channel recording device (ApneaLink) plus clinical data for the prescription of a CPAP assay in patients with suspected OSA. Methods. 39 subjects were assessed in the sleep laboratory with polysomnography and ApneaLink. The patients completed the Epworth sleepiness scale and a clinical history. Two blinded independent observers decided to prescribe CPAP according to the results of the PSG (gold standard, observer A), ApneaLink (alternative method, observer B), and the clinical parameters. Sensitivity and specificity of observer B on the indication of CPAP were calculated. The interobserver agreement for the indication of CPAP was assessed using kappa statistics. Results. 38 subjects were included (26 men, mean age 47.5, mean RDI 28.7, mean BMI 31.4 kg/m(2)). The prevalence of OSA was 84%. The sensitivity and specificity of observer B to initiate a CPAP trial were 90.6% and 100%, respectively. The interrater agreement for the prescription of CPAP was good (kappa: 0.75). Conclusion. This study has shown that the use of ApneaLink plus clinical data has made it possible to indicate CPAP reliably in most patients with high-clinical pretest for OSA.

Altered Luteinizing Hormone and Testosterone Secretion in Middle-Aged Obese Men with Obstructive Sleep Apnea

OBJECTIVE

To elucidate the causes for the decline in testosterone levels observed in men with obstructive sleep apnea (OSA).

RESEARCH METHODS AND PROCEDURES

We determined serum luteinizing hormone (LH) and testosterone levels every 20 minutes between 7 pm and 7 am with simultaneous sleep recordings in five obese middle-aged men with OSA, in five age- and BMI-matched controls, and in six lean young healthy men.

RESULTS

The mean and area under the curve (AUC) values of LH and testosterone were significantly lower in men with OSA compared with controls. Young controls had significantly more testosterone pulses of shorter interpulse duration than OSA subjects and middle-aged controls. After adjusting for age and BMI, the three groups differed in mean and AUC values of LH and testosterone. Analysis of covariance, using BMI as a covariate, revealed a statistically significant group effect on mean and AUC testosterone values (p = 0.03; p < 0.003, respectively). Eliminating young controls, there was a significant positive correlation between the amount of LH and testosterone secreted at night. After partialling out age alone and BMI alone, the mean LH and mean testosterone were still positively correlated.

DISCUSSION

Thus, OSA is associated with decreased pituitary-gonadal function. The decline in testosterone concentrations is due to obesity and advanced age and to a lesser degree to sleep fragmentation and hypoxia.

Snoring is not associated with all-cause mortality, incident cardiovascular disease, or stroke in the Busselton Health Study

STUDY OBJECTIVES

To ascertain whether objectively measured snoring increases mortality, cardiovascular disease, or stroke risk over the effects of obstructive sleep apnea and other established risk factors.

DESIGN

Community-based cohort.

PARTICIPANTS

400 residents of the Western Australian town of Busselton.

INTERVENTIONS

N/A.

MEASUREMENTS

Snoring and obstructive sleep apnea were quantified via the percentage of the night spent snoring and the respiratory disturbance index as measured by a single night recording in November-December 1990 by a home sleep apnea monitoring device (MESAM IV), along with a range of cardiovascular disease risk factors. Follow-up for deaths and cardiovascular hospitalizations was ascertained via record linkage until the end of 2007.

RESULTS

Our analytical sample of 380 people was made up of the 397 people for whom the authors had follow-up data, minus 17 people who reported a previous stroke or heart attack at baseline (n = 380/400 = 95% of cohort). Snoring was observed for a mean/median of 32.0/27.4% of the night (standard deviation = 23.9%; range = 0-97.2%). There were 46 deaths, 68 cardiovascular events, and 24 strokes during 17 yr of follow-up. Snoring as either a categoric or continuous variable was not significantly associated with death, incident cardiovascular disease, or stroke in both unadjusted Cox regression models and in models that adjusted for obstructive sleep apnea and other risk factors.

CONCLUSIONS

No measure of snoring was associated with all-cause mortality, or incident cardiovascular disease or stroke over 17 yr in this community-based sample.

Validation of ApneaLink Ox™ for the diagnosis of obstructive sleep apnea

OBJECTIVE

The aim of the study was to validate the automatic and manual analysis of ApneaLink Ox™ (ALOX) in patients with suspected obstructive sleep apnea (OSA).

METHODS

All patients with suspected OSA had a polysomnography (PSG) and an ALOX performed in the sleep laboratory. For automatic analysis, hypopnea was defined as a decrease in airflow ≥30 % of baseline for at least 10 s plus oxygen desaturation ≥3 or 4 %. While for the manual analysis, hypopnoea was considered when a reduction of airflow ≥30 % of ≥10 s plus oxygen desaturation ≥3 % or increase in cardiac rate ≥5 beats/min were identified or, when only a reduction of airflow ≥50 % was observed. OSA was defined as a respiratory disturbance index (RDI) ≥5. The apnea/hypopnea automatic index (AHI3-a, AHI4-a) and manual index were estimated. Receiver operating characteristics (ROC) analysis and the agreement between ALOX and PSG were performed.

RESULTS

Fifty-five patients were included (38 men; mean age, 48.2; median, RDI 15.1; median BMI, 30 Kg/m(2)). The automatic analysis of ALOX under-estimated the RDI from PSG, mainly for the criterion of oxygen desaturation ≥4 % (AHI3-a-RDI, -3.6 ± 10.1; AHI4-a-RDI, -6.5 ± 10.9, p < 0.05). The autoscoring from ALOX device showed a better performance when it was set up to identify hypopneas with an oxygen desaturation criterion of ≥3 % than when it was configured with an oxygen desaturation criterion of ≥4 % (area under the receiver operator curves, 0.87 vs. 0.84). Also, the manual analysis was found to be better than the autoscoring set up with an oxygen desaturation of ≥3 % (0.923 vs. 0.87). The manual analysis showed a good interobserver agreement for the classification of patients with or without OSA (k = 0.81).

CONCLUSION

The AHI obtained automatically from the ApneaLink Ox™ using oxygen desaturation ≥3 % as a criterion of hypopnea had a good performance to diagnose OSA. The manual scoring from ApneaLink Ox™ was better than the automatic scoring to discriminate patients with OSA.

Auto-titrating versus fixed continuous positive airway pressure for the treatment of obstructive sleep apnea: a systematic review with meta-analyses

BACKGROUND

Obstructive sleep apnea is a relatively common disorder that can lead to lost productivity and cardiovascular disease. The form of positive airway treatment that should be offered is unclear.

METHODS

MEDLINE and the Cochrane Central Trials registry were searched for English language randomized controlled trials comparing auto-titrating positive airway pressure (APAP) with continuous positive airway pressure (CPAP) in adults with obstructive sleep apnea (inception through 9/2010). Six researchers extracted information on study design, potential bias, patient characteristics, interventions and outcomes. Data for each study were extracted by one reviewer and confirmed by another. Random effects model meta-analyses were performed for selected outcomes.

RESULTS

Twenty-four randomized controlled trials met the inclusion criteria. In individual studies, APAP and fixed CPAP resulted in similar changes from baseline in the apnea-hypopnea index, most other sleep study measures and quality of life. By meta-analysis, APAP improved compliance by 11 minutes per night (95% CI, 3 to 19 minutes) and reduced sleepiness as measured by the Epworth Sleepiness Scale by 0.5 points (95% CI, 0.8 to 0.2 point reduction) compared with fixed CPAP. Fixed CPAP improved minimum oxygen saturation by 1.3% more than APAP (95% CI, 0.4 to 2.2%). Studies had relatively short follow-up and generally excluded patients with significant comorbidities. No study reported on objective clinical outcomes.

CONCLUSIONS

Statistically significant differences were found but clinical importance is unclear. Because the treatment effects are similar between APAP and CPAP, the therapy of choice may depend on other factors such as patient preference, specific reasons for non-compliance and cost.

[Sleep-disordered breathing and cardiac resynchronization therapy]

Patients with progressive heart failure often suffer from sleep-disordered breathing (SDB). Upon receiving cardiac resynchronization therapy (CRT), there is an improvement of cardiac function and central sleep apnea syndrome (CSA) with Cheyne-Stokes respiration; however, effects of CRT on obstructive sleep apnea syndrome seemed to be without clinical relevance. Likewise, additional atrial overdrive pacing did not improve CRT effects relevantly in CSA patients. During CRT, there is an improvement in sleep parameters, sleep quality by reduction of depressive syndromes, and in long-term survival. Therefore, all patients with chronic heart failure and indication for CRT should be monitored regarding SDB before and after CRT device implantation.

Effects of dietary weight loss on obstructive sleep apnea: a meta-analysis

PURPOSE

Clinical and epidemiologic investigations suggest a strong association between obesity and obstructive sleep apnea (OSA). The purpose of this study is to evaluate the currently available literature reporting on the effectiveness of dietary weight loss in treating OSA among obese patients.

METHODS

Relevant studies were identified by computerized searches of PubMed, EMBASE, CINAHL, Web of Science, and The Cochrane Central Register of Controlled Trials through September 2011 as well as the reference lists of all obtained articles. Information on study design, patient characteristics, pre- and post-dietary weight loss measures of OSA and body mass index (BMI), and study quality was obtained. Data were extracted by two independent analysts. Weighted averages using a random-effects model are reported with 95 % confidence intervals.

RESULTS

Nine articles representing 577 patients were selected. Dietary weight loss program resulted in a pooled mean BMI reduction of 4.8 kg/m(2) (95 % confidence interval [CI] 3.8-5.9). The random-effects pooled apnea hypopnea (AHI) indices at pre- and post-dietary intervention were 52.5 (range 10.0-91.0) and 28.3 events/h (range 5.4-64.5), respectively (p < 0.001). Compared to control, the weighted mean difference of AHI was decreased by -14.3 events/h (95 % CI -23.5 to -5.1; p = 0.002) in favor of the dietary weight loss programs.

CONCLUSIONS

Dietary weight loss programs are effective in reducing the severity of OSA but not adequate in relieving all respiratory events. Weight reduction programs should be considered as adjunct rather than curative therapy.

Assessment of multiple health risks in a single obstructive sleep apnea population

STUDY OBJECTIVES

In order to provide a comprehensive estimate of the health risks for OSA patients, we analyzed multiple outcomes and independent predictors of these outcomes in an OSA population evaluated and followed at one sleep center.

METHODS

Cox proportional hazard regression analyses were used in an 8-year follow-up analysis of consecutive OSA patients (N = 1025) and non-apneic snorers (apnea-hypopnea index < 5, N = 494).

RESULTS

In our fully adjusted model, independent variables predictive of all-cause mortality, myocardial infarction, cerebral vascular accident, and pulmonary embolus were: older age, male gender, and history of cardiovascular diseases or procedures. In examining subgroups based on age and gender, severe OSA (AHI ≥ 30) was one of the independent predictors of mortality in males and in patients < 50 years old. Severe OSA interacted with maleness, age, and hypertension to predict mortality and myocardial infarction. CPAP use ≥ 4 h/night was associated with lower mortality rates in males and those ≥ 50 years old with severe OSA.

CONCLUSIONS

Mortality and cardiovascular event outcomes were predicted by demographics and cardiovascular disease history more commonly than by OSA severity. OSA severity was an important predictor of mortality in male and young OSA patients. CPAP use appeared protective in older and male severe OSA patients.

Membrane level of omega-3 docosahexaenoic acid is associated with severity of obstructive sleep apnea

BACKGROUND

Patients with obstructive sleep apnea (OSA) are at increased risk of cardiovascular disease (CVD). The omega-3 fatty acid docosahexaenoic acid (DHA) is a major component of neural tissues, and supplementation with fish oils improves autonomic tone and reduces risk for CVD. A link between low DHA status and less mature sleep patterns was observed in newborns.

METHODS

We investigated the relations between red blood cell (RBC) levels of DHA and OSA severity in 350 sequential patients undergoing sleep studies. Severity categories were defined as none/mild, moderate, and severe, based on apnea hypopnea index (AHI) scores of 0 to 14, 15 to 34, and > 34, respectively.

RESULTS

After controlling for age, sex, race, smoking, BMI, alcohol intake, fish intake, and omega-3 supplementation, RBC DHA was inversely related with OSA severity. For each 1-SD increase in DHA levels, a patient was about 50% less likely to be classified with severe OSA. The odds ratios (95% CI) were 0.47 (0.28 to 0.80) and 0.55 (0.31 to 0.99) for being in the severe group versus the none/mild or moderate groups, respectively.

CONCLUSION

These findings suggest that disordered membrane fatty acid patterns may play a causal role in OSA and that the assessment of RBC DHA levels might help in the diagnosis of OSA. The effects of DHA supplementation on OSA should be explored.

Relationship between sleep-disordered breathing and markers of systemic inflammation in women from the general population

Sleep-disordered breathing (SDB) is a risk factor for cardiovascular disease (CVD). The underlying pathogenesis is not clear. In patients with obstructive sleep apnoea syndrome (OSAS) elevated levels of inflammatory markers, such as C-reactive protein (CRP), interleukin-6 (IL-6) and tumour necrosis factor α (TNFα) have been found. These markers have also been shown as independent markers of CVD in other populations. The aim of the study was to investigate the association between SDB and systemic inflammation in a population-based cohort of women. From 6817 women who previously answered a questionnaire concerning snoring habits, 230 habitually snoring women and 170 women regardless of snoring status went through polysomnography, anthropometric measurements and blood sampling. Analyses were made for CRP, TNFα, IL-6, myeloperoxidase (MPO) and lysozyme. The levels of CRP, IL-6 and lysozyme were significantly higher in subjects with apnoea-hypopnoea index (AHI) ≥15 compared with women with lower AHI. All inflammatory markers except MPO correlated to AHI and oxygen desaturation measures, and to waist circumference. In multiple linear regressions adjusting for age, waist circumference and smoking, independent correlations between oxygen desaturation indices (ODI) and inflammation were found for IL-6 (P = 0.03 for % sleep time with saturation <90%) and TNFα (P = 0.03 for ODI 3%). No significant correlations were found between AHI and inflammation. Also, for women from the general population there is an independent correlation between SDB and inflammation, even after adjusting for obesity. The results indicate that intermittent hypoxia, and not the AHI, is related to systemic inflammation seen in OSAS.

Snoring is not associated with adverse effects on blood pressure, arterial structure or function in 8-year-old children: the Childhood Asthma Prevention Study (CAPS)

AIMS

To study the association between childhood snoring and cardiovascular risk factors.

METHODS

Cross-sectional analyses of a population-based birth cohort, who had been participants in a randomised controlled trial of interventions to prevent asthma and who were assessed at age 8 years. The presence and frequency of snoring were assessed by parent-completed questionnaire. We measured a wide range of cardiovascular function markers including non-fasting serum lipoproteins, blood pressure, high-sensitivity C-reactive protein, carotid artery intima media thickness (by ultrasound), brachial pulse wave velocity and augmentation index (by applanation tonometry).

RESULTS

Of 409 children whose snoring status was assessed at age 8 years, 321 had lipid and 386 had arterial structure and function measurements. Snoring was not independently associated with blood pressure, carotid artery intima media thickness or measures of arterial stiffness (all P > 0.05). Increasing snoring frequency was independently associated with lower high-density lipoprotein cholesterol (-0.032 g/dL per step, 95% confidence interval -0.060 to -0.003), although the difference in high-density lipoprotein between snorers and non-snorers was not significant (P = 0.052). An association of snoring frequency with brachial pulse wave velocity differed according to body mass index (P = 0.03) and was the reverse of that expected.

CONCLUSIONS

Parentally reported snoring was not independently associated with adverse measurements of metabolic markers, vascular structure or function in 8-year-old children. Parental reports of snoring may be below the treatment threshold without additional diagnosis via sleep studies.

Sleep disordered breathing in community dwelling elderly: associations with cardiovascular disease, impaired systolic function, and mortality after a six-year follow-up

INTRODUCTION

Sleep disordered breathing (SDB), cardiovascular disease (CVD) and impaired cardiac function are common in elderly people. We investigated the association of SDB and mortality in a community dwelling elderly population, considering CVD and objectively measured impaired cardiac function have been poorly studied thus far.

AIM

To investigate whether SDB is a factor that affects mortality in elderly people, with a focus on those with CVD and/or signs of impaired cardiac function.

METHODS

A prospective cohort design was used and 331 community dwelling elderly aged 71-87 years underwent one-night polygraphic recordings in the subjects' homes. CVD and systolic function were objectively established. Mortality data were collected after 6 years.

RESULTS

In the total population there were no significant associations between mortality and SDB. In those with CVD and impaired systolic function, as measured by NT-proBNP, oxygen desaturation index (ODI) ≥10 was associated with mortality. The hazard ratio of 3.0 (CI 95% 1.1-8.6, p=0.03) remained statistically significant after adjustments for age, gender, diabetes and plasma values of NT-proBNP.

CONCLUSION

SDB in community dwelling elderly has no overall association to mortality irrespective of degree of SDB. However, hypoxic events (i.e., ODI ≥10) were associated with mortality in the group who had CVD in combination with impaired systolic function.

Treatment of obstructive sleep apnea reduces arterial stiffness

PURPOSE

A close relationship between obstructive sleep apnea (OSA) and atherosclerosis has been reported, but it is still discussed controversially whether OSA affects vascular function and structure independently. Therefore, we prospectively investigated the independent impact of OSA and its treatment on arterial stiffness.

METHODS

One hundred seventy-two patients with suspected OSA were prospectively enrolled in a non-randomized 6-month study to determine whether effective treatment (respiratory events sufficiently reduced and proven compliance) of OSA with continuous positive airway pressure (CPAP) would affect vascular function as measured by augmentation index (Aix) and pulse wave velocity (PWV). Additionally, using a nested case-control, we matched 45 pairs of patients with and without OSA for gender, age, and hypertension.

RESULTS

Overall, OSA (n = 117) was associated with increased Aix (23.6 ± 13.5 vs. 8.9 ± 13.7, p < 0.001) and PWV (9.1 ± 1.6 vs. 7.8 ± 1.6 m/s, p < 0.001) as compared with that in controls without OSA (n = 55). Multivariable analysis and results from the nested case-control cohort showed that OSA was associated with increased Aix and PWV independently from hypertension, age, gender, body mass index, and antihypertensive medications. In 49 effectively treated OSA patients, Aix (baseline 22.0 ± 13.4, follow-up 20.1 ± 12.9, p < 0.01) and PWV (baseline 9.6 ± 1.5, follow-up 8.7 ± 1.4, p < 0.05) had improved. In contrast, ineffectively treated OSA patients (n = 39) showed no change in Aix and PWV.

CONCLUSIONS

This prospective controlled study suggests that OSA is independently associated with increased arterial stiffness. Furthermore, treatment with CPAP significantly reduced arterial stiffness. These findings extend our understanding of the recently shown cardiovascular burden in OSA and help to explain why CPAP treatment proved to ameliorate cardiovascular outcome even in patients without preexisting cardiovascular disease.

Risk of stroke from sleep apnea in men and women

Obstructive sleep apnea (OSA) is a common sleep disorder, and research on the effects of sleep apnea is important to gain insight into how sleep affects health. Untreated OSA has been associated with important health consequences, such as an increased risk for hypertension, cardiovascular disease and diabetes. Previous studies have shown that OSA also represents a risk factor for stroke. The relationship between OSA and stroke is particularly relevant, as stroke is the second leading cause of death globally. The reviewed article presents new data from the Sleep Heart Health Study, a longitudinal cohort study, which shows an association between incident stroke and untreated OSA of varying severity for men and possibly more severe OSA for women. The study is discussed in the context of the current state of knowledge about OSA, in particular its health consequences, and the general limitations in conducting research with OSA patients.

Increased arterial stiffness in obstructive sleep apnea: a systematic review

Obstructive sleep apnea is a prevalent disease that is associated with significant morbidity and mortality, particularly due to cardiovascular disease. An emerging cardiovascular risk factor, arterial stiffness, may also be involved in the cardiovascular complications of obstructive sleep apnea. The purpose of this review was to summarize the current literature regarding the effect of obstructive sleep apnea on arterial stiffness. We conducted a systematic literature review using PubMed, Embase and the Cochrane Library. We identified 24 studies that met search criteria investigating the effect of obstructive sleep apnea on arterial stiffness. Arterial stiffness was found to be increased in obstructive sleep apnea patients compared with controls or increased in severe compared with mild sleep apnea. In some studies, a positive correlation was identified between the degree of arterial stiffness and sleep apnea severity. In the two randomized, controlled trials and the two nonrandomized trials identified, treatment of obstructive sleep apnea with continuous positive airway pressure led to significant decreases in arterial stiffness. Obstructive sleep apnea appears to have an independent effect on arterial stiffness, which may be one of the mechanisms accounting for sleep apnea-associated cardiovascular risk.

Aging and sleep: physiology and pathophysiology

Aging effects on sleep are important to consider for the practicing pulmonologist due to the increase in prevalence of major respiratory disorders as well as the normal changes that occur in sleep patterns with aging. Typically, aging is associated with decreases in the amount of slow wave sleep and increases in stage 1 and 2 non-rapid eye movement sleep, often attributed to an increased number of spontaneous arousals that occur in the elderly. Elderly individuals tend to go to sleep earlier in the evening and wake earlier due to a phase advance in their normal circadian sleep cycle. Furthermore the development of sleep-related respiratory disorders such as obstructive sleep apnea (OSA) and central sleep apnea or Cheyne-Stokes respiration (CSA-CSR) associated with congestive heart failure (CHF) occur with increasing prevalence in the elderly. The development of such disorders is often of major concern because they are associated with systemic hypertension and cardiovascular disease, metabolic disorders such as diabetes, and impaired neurocognition. The present review reflects the current understanding of the normal changes in sleep patterns and sleep needs with advancing age, in addition to the effect that aging has on the predisposition to and consequences of OSA and CSA-CSR associated with CHF.

Endocrine aspects of obstructive sleep apnea

CONTEXT

Some endocrine and metabolic disorders are associated with a high frequency of obstructive sleep apnea (OSA), and treatment of the underlying endocrine disorder can improve and occasionally cure OSA. On the other hand, epidemiological and interventional studies suggest that OSA increases the cardiovascular risk, and a link between OSA and glucose metabolism has been suggested, via reduced sleep duration and/or quality.

EVIDENCE ACQUISITION

We reviewed the medical literature for key articles through June 2009.

EVIDENCE SYNTHESIS

Some endocrine and metabolic conditions (obesity, acromegaly, hypothyroidism, polycystic ovary disease, etc.) can be associated with OSA. The pathophysiological mechanisms of OSA in these cases are reviewed. In rare instances, OSA may be improved or even cured by treatment of underlying endocrine disorders: this is the case of hypothyroidism and acromegaly, situations in which OSA is mainly related to upper airways narrowing due to reversible thickening of the pharyngeal walls. However, when irreversible skeletal defects and/or obesity are present, OSA may persist despite treatment of endocrine disorders and may thus require complementary therapy. This is also frequently the case in patients with obesity, even after substantial weight reduction.

CONCLUSIONS

Given the potential neurocognitive consequences and increased cardiovascular risk associated with OSA, specific therapy such as continuous positive airway pressure is recommended if OSA persists despite effective treatment of its potential endocrine and metabolic causes. "Apropos of sleep, that sinister adventure of all our nights, we might say that men go to bed daily with an audacity that would be incomprehensible if we did not know that it is the result of ignorance of the danger." Charles Baudelaire, in "Fusées, IX"

Sleep duration and the risk of diabetes mellitus: epidemiologic evidence and pathophysiologic insights

Evidence from well-defined cohort studies has shown that short sleep, through sleep fragmentation caused by obstructive sleep apnea (OSA) or behavioral sleep curtailment because of lifestyle choices, is associated with increased incidence of diabetes. In this report, we review epidemiologic and clinical data suggesting that OSA is involved in the pathogenesis of altered glucose metabolism. Evidence suggesting increased risk of developing diabetes resulting from curtailed sleep duration is also considered. Proposed mechanisms explaining associations between short sleep and diabetes are examined and clinical management of OSA among patients with diabetes is discussed.

Sleep-disordered breathing and mortality: a prospective cohort study

BACKGROUND

Sleep-disordered breathing is a common condition associated with adverse health outcomes including hypertension and cardiovascular disease. The overall objective of this study was to determine whether sleep-disordered breathing and its sequelae of intermittent hypoxemia and recurrent arousals are associated with mortality in a community sample of adults aged 40 years or older.

METHODS AND FINDINGS

We prospectively examined whether sleep-disordered breathing was associated with an increased risk of death from any cause in 6,441 men and women participating in the Sleep Heart Health Study. Sleep-disordered breathing was assessed with the apnea-hypopnea index (AHI) based on an in-home polysomnogram. Survival analysis and proportional hazards regression models were used to calculate hazard ratios for mortality after adjusting for age, sex, race, smoking status, body mass index, and prevalent medical conditions. The average follow-up period for the cohort was 8.2 y during which 1,047 participants (587 men and 460 women) died. Compared to those without sleep-disordered breathing (AHI: <5 events/h), the fully adjusted hazard ratios for all-cause mortality in those with mild (AHI: 5.0-14.9 events/h), moderate (AHI: 15.0-29.9 events/h), and severe (AHI: >or=30.0 events/h) sleep-disordered breathing were 0.93 (95% CI: 0.80-1.08), 1.17 (95% CI: 0.97-1.42), and 1.46 (95% CI: 1.14-1.86), respectively. Stratified analyses by sex and age showed that the increased risk of death associated with severe sleep-disordered breathing was statistically significant in men aged 40-70 y (hazard ratio: 2.09; 95% CI: 1.31-3.33). Measures of sleep-related intermittent hypoxemia, but not sleep fragmentation, were independently associated with all-cause mortality. Coronary artery disease-related mortality associated with sleep-disordered breathing showed a pattern of association similar to all-cause mortality.

CONCLUSIONS

Sleep-disordered breathing is associated with all-cause mortality and specifically that due to coronary artery disease, particularly in men aged 40-70 y with severe sleep-disordered breathing. Please see later in the article for the Editors' Summary.

[Smoking and sleep disorders]

Snoring and sleep apnea-hypopnea syndrome (SAHS) are two disorders of considerable relevance due to their high prevalence in the general population and their notable morbidity and mortality, particularly in association with their harmful effects on the cardiovascular system. As well as sex, age, weight, craniofacial malformations, alcohol consumption, and use of hypnotic drugs, it has been suggested that smoking may be a risk factor for developing sleep-disordered breathing. While there is solid evidence for the independent association between snoring and smoking in both children and adults, it is still unclear whether smoking constitutes an independent risk factor for developing SAHS, despite the many studies carried out to assess this link. This is probably because the association, if it exists, is very weak.

Blood pressure increase detected by ambulatory monitoring correlates with hypoxemia reflecting sleep apnea severity

Ambulatory blood pressure monitoring and parallel polysomnographic study were performed in 116 adult males divided into 6 groups. Thirty blood-pressure (BP) and polysomnographic variables were measured to test their usefulness for screening for both arterial hypertension and sleep apnea-hypopnea syndrome (SAHS). The development of severe breathing disorders and hypoxemia during sleep was attributed to SAHS, when compared with measurements in healthy controls and in patients with arterial hypertension. Such disorders manifested as an increased apnea-hypopnea index, apnea index, duration of arterial oxygen saturation of less than 85%, and decrease of average arterial oxygen saturation that correlated with nocturnal average diastolic BP (p=0.0049, p=0.0027, p=0.049 and p=0.0457, respectively). These respiratory disorders resulted in various nocturnal, rather than diurnal, and diastolic and systolic BP variables. The acute antihypertensive effect of continuous positive airway pressure therapy for SAHS significantly reduced the episodes of apnea and hypopnea and the secondary component of hypertension caused by excessive sympathetic stimulation. For the SAHS-induced, dose-dependent component of hypertension that responded to continuous positive airway pressure, the following variables, in decreasing significance, were useful: nocturnal average systolic and diastolic BP and 24-hour average systolic and diastolic BP, as well as percent time elevation and mean blood pressure load. The monitoring of these variables could contribute to early diagnostic and prognostic stratification of complications and adequate therapy of the secondary component of hypertension caused by SAHS.

Obstructive sleep apnea and atherosclerosis

Obstructive sleep apnea (OSA) is associated with significant cardiovascular morbidity and excess in mortality. Atherosclerosis has been shown to occur in OSA patients free of any other significant risk factors. In particular, intima media thickness, an early marker of atherosclerosis, may be increased at the carotid level in OSA. Thus, early atherosclerosis could be one of the intermediary mechanisms supporting the link between OSA and cardiovascular morbidity. The current concept is that the development of atherosclerotic lesions results from a dynamic interplay between the native cells of the vasculature and different proinflammatory leukocytes issued from the general circulation. Immunoinflammatory cells dominate early atherosclerotic processes, with the secretion of several proinflammatory molecules aggravating lesion progression. There is now substantial evidence that intermittent hypoxia in rodents, as a partial model of sleep apnea, triggers atherogenesis. Blood pressure alterations and hemodynamic strains on the vascular wall, impairment in vascular reactivity, lipid metabolism dysregulation, and activation of proinflammatory transcription factors at the vascular wall level are among the key factors promoting atherosclerosis. Specifically, increases in leukocyte rolling and adhesion molecule expression at the endothelial cell level have been shown to occur in the first 2 weeks after intermittent hypoxia exposure initiation. Early changes at the vascular wall level have been shown in OSA patients and its reversibility under continuous positive airway pressure has also been suggested. Several biological markers potentially linked with early atherosclerosis development are under study in OSA patients. Further studies are needed to identify at-risk subjects prone to develop vascular changes because OSA treatment may either be initiated earlier or combined with specific drug treatments.

Obstructive sleep apnoea/hypopnea influences high-density lipoprotein cholesterol in the elderly

BACKGROUND AND PURPOSE

An association between obstructive sleep apnoea/hypopnea (OSAH) and cardiovascular risk factors such as dyslipidemia has been described in adults and high-risk populations.

PATIENTS AND METHODS

We examined this association in a prospective cohort (SYNAPSE study) of 846 elderly (68.5+/-1.1 years) volunteers (41.6% of men). No subject presented with recognized OSAH syndrome, heart disease, or any neurological disorder. Unattended at-home polygraphy was done by all subjects. OSAH severity was defined as moderate (apnoea/hypopnea index: AHI>15/h) or severe (AHI>30/h). High-density lipoprotein cholesterol (HDL-c) was measured by immuno-separation-based homogenous assay.

RESULTS

The prevalence of severe cases reached 21.5% (AHI mean+/-SD: 43.5+/-11.9). Using univariate linear regression analysis, AHI (R=-0.172; p<0.0001), oxyhemoglobin desaturation index (ODI) (R=-0.108; p<0.002), mean SaO(2) (R=0.125; p<0.0003) and Nadir SaO(2) (R=0.094; p<0.007) were significantly associated with HDL-c. Multiple regression analysis demonstrated that male gender, BMI, waist to hip ratio, ODI, and AHI represent independent predictors of HDL-c. Logistic regression analysis showed a significant association between severe OSAH and low HDL-c serum levels (p<0.03) after adjustment for gender, BMI, hypertension, glycaemia, waist to hip ratio, alcohol intake and treated dyslipidemia. The association appears more evident in subjects free of lipid-lowering medications and beta-blockers (p<0.007). There was no independent association of OSAH syndrome with low-density lipoprotein (LDL) cholesterol.

CONCLUSION

Unrecognized moderate to severe apnoea/hypopnea syndrome was independently associated with low HDL-c serum levels in the present cross-sectional based elderly population. This could explain the deleterious effect of OSAH syndrome on cardiovascular risk.

Symptoms of obstructive sleep apnea in a Caribbean sample

Obstructive sleep apnea (OSA) is a prevalent sleep disorder that disproportionately affects blacks. While clinical and epidemiologic data indicate intraethnic differences in several medical diseases, little is known about whether OSA symptoms differ within the black ethnic group. We estimated the rate of OSA symptoms in a community-based sample of Caribbean-born black men and women. We also ascertained which sociodemographic and/or medical factors were associated with OSA risk. A total of 554 patients (mean age = 48.17 +/- 16.75 years) participated in the study; 55% were women. Data were collected in four primary-care clinics in Brooklyn, NY. A health educator explained the purpose of the study to interested patients and assisted consenting participants in completing questionnaires, which required 15 min to complete. Participants reporting habitual snoring, excessive daytime sleepiness, and sleep fragmentation were considered at high OSA risk. The rate of OSA symptoms was: snoring (45%), excessive daytime sleepiness (33%), and difficulty maintaining sleep (34%). Many reported falling asleep while watching television (47%) or while driving (14%). Based on logistic regression analysis, a history of heart disease was the most important predictor of the likelihood of expressing OSA symptoms, with a corresponding multivariate-adjusted odds ratio of 11 (95% confidence interval = 3.03-40.63). Findings suggest the need to investigate whether Caribbean-born blacks are at greater risk for developing OSA than African Americans and whites. Caribbean-born blacks with a history of heart disease should be a prime target for interventions that promote adequate screening and timely OSA diagnosis.