All-cause mortality in males with sleep apnoea syndrome: declining mortality rates with age

Sleep apnoea syndrome as a risk for mortality in elderly inpatients

OBJECTIVE

The characteristics of sleep apnoea syndrome (SAS) in the elderly, including subtype classification and association with mortality, have not been fully elucidated. This study examined these factors in an elderly Japanese inpatient population.

METHODS

Overnight polysomnography was used to diagnose and classify SAS in 145 elderly inpatients (mean ± age 81 ± 8 years). Clinical data, including brain computerized tomography findings, were recorded. The study population included nine inpatients with obstructive SAS, 12 with central SAS, 25 with mixed SAS and 99 controls (no SAS).

RESULTS

Increased body mass index and grade of aortic arch calcification independently contributed to risk of all subtypes of SAS combined. There was an independent association between SAS and increased risk of mortality from all causes as well as from pneumonia and from cardiovascular disease. Only mixed SAS was independently and positively associated with increased risk of death from pneumonia.

CONCLUSIONS

Obstructive, central and mixed SAS were associated with increased risk of cardiovascular related and all-cause mortality. Mixed SAS was associated with an increase in mortality from pneumonia. There was no relationship between mortality and severity of SAS.

Obstructive sleep apnoea and cardiovascular disease

Obstructive sleep apnoea (OSA) is a common health concern caused by repeated episodes of collapse of the upper airway during sleep. The events associated with OSA lead to brain arousal, intrathoracic pressure changes, and intermittent episodes of hypoxaemia and reoxygenation. These events activate pathways such as oxidative stress, sympathetic activation, inflammation, hypercoagulability, endothelial dysfunction, and metabolic dysregulation that predispose patients with OSA to hypertension and atherosclerosis. OSA is a common cause of systemic hypertension and should be suspected in hypertensive individuals, especially those with resistant hypertension. In patients with OSA, continuous positive airway pressure (CPAP) treatment reduces blood pressure, and its effects are related to compliance and baseline blood pressure. Evidence suggests that OSA is a risk factor for stroke and heart failure. An association between coronary heart disease and OSA seems to be limited to middle-aged men (30-70 years). Cardiac rhythm disorders occur in about half of patients with OSA, but their clinical relevance is still unknown. The association of OSA with cardiovascular risk is mainly based on studies in men, and an association has yet to be established in women. Data on older patients is similarly scarce. Currently, there is not enough evidence to support treatment with CPAP for primary or secondary prevention of cardiovascular disease.

Treatment of obstructive sleep apnea in patients with cardiac arrhythmias

OPINION STATEMENT

Obstructive sleep apnea (OSA) is the most common form of sleep-disordered breathing that is prevalent in the population and frequently under diagnosed. Usually presenting with respiratory symptoms, the most significant consequences of OSA are cardiovascular, including arrhythmias. The pathophysiology of OSA through multiple mechanisms may promote bradyarrhythmias, atrial fibrillation, premature ventricular complexes, ventricular arrhythmias, and sudden death. These mechanisms may acutely trigger nocturnal arrhythmias and may chronically affect electrical and structural myocardial changes, causing arrhythmias. Numerous epidemiological data have identified an increased risk for atrial fibrillation, ventricular fibrillation and sudden death in subjects with OSA. Diagnosis of OSA should be considered in patients with arrhythmias. However, not all patients with arrhythmias need to undergo formal testing for sleep apnea. Patients who are observed to have nocturnal arrhythmias should be considered for evaluation for possible OSA. Also, if the arrhythmia is refractory to standard therapy and if other clinical indicators of OSA are also present, there should be a low threshold for pursuing the diagnosis of sleep apnea. The principal therapy for OSA is continuous positive airway pressure (CPAP). Currently, there are limited data to support the efficacy of CPAP for arrhythmia prevention or treatment. Randomized trials are necessary to determine the efficacy of OSA treatment on arrhythmia prevention.

Central sleep apnea is associated with increased risk of ischemic stroke in the elderly

OBJECTIVES

Sleep apnea/hypopnea syndrome is a well-recognized independent risk factor for stroke in middle-aged population, but controversy remains in older subjects. We examined the possible association between different respiratory parameters and risk of stroke in a prospective population-based cohort of 394 stroke-free elderly subjects.

MATERIAL AND METHODS

Fully overnight polysomnography was performed at baseline. Over the 6 year follow-up period, 20 ischemic strokes occurred. Differences in stroke-free survival between subjects according to central apnea index (CAI) were assessed.

RESULTS

We just observed association with incident ischemic stroke on central sleep apnea (CSA) episodes. Obstructive sleep apnea, time passed under 90% oxygen saturation, or arousal index were not associated. The event-free survival was lowest in the highest CAI group. This association was independent of any other vascular risk factors.

CONCLUSIONS

CSA is the specific respiratory event associated with stroke in the elderly. Additionally, CSA could be a marker of silent brain ischemia, as a sign of disturbed regulation of central respiratory mechanisms, tentatively of ischemic origin.

The association between sleep apnea and young adults with hypertension

OBJECTIVES/HYPOTHESIS

To study the association between sleep apnea and hypertension in a younger age group than previously studied, adding upper airway sizes at endoscopy as important compounding variables not often included in the past.

STUDY DESIGN

Case control.

METHODS

We analyzed data on sleep-disordered breathing (based on polysomnography tests), body mass index (BMI), neck circumference, upper airway endoscopy sizes, and habitus and health history in 120 hypertensive and 120 nonhypertensive participants in a clinic-based setting. Independent t test, χ(2) , multivariate analysis, and binary logistic regression models were used for case-control comparison.

RESULTS

The mean age of the participants was 27 years; 67.5% were male. The incidence and severity of sleep apnea were significantly higher in the hypertensive than the control subjects. Persons with hypertension had an OR of 2.7 times of having comorbid sleep apnea than patients without hypertension (95% confidence interval [CI] 1.2-6.1). Persons with sleep apnea (AHI [apnea-hypopnea index] ≥ 5) had an OR of 2.76 (95% CI 1.57-4.86), and persons with severe sleep apnea (AHI ≥ 30) had an OR 7.94 (95% CI 4.21-15.33) for having hypertension than did persons without sleep apnea. Although adjustments for the compounding factors, particularly BMI, decreased the OR to a large degree, subjects with severe sleep apnea were still 72% more likely to have hypertension than subjects without sleep apnea.

CONCLUSIONS

Sleep apnea is related to hypertension in young adults aged 18 to 40 years. The association was more pronounced with the increasing severity of sleep apnea. Screening for sleep apnea should be considered in young adults with hypertension.

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.

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.

An epidemiologic study of snoring and all-cause mortality

OBJECTIVE

Snoring is a common problem that is often associated with obstructive sleep apnea syndrome (OSAS). However, it is suggested that snoring may itself be harmful. Patients with objectively measured snoring were matched against a mortality database and associations were explored.

STUDY DESIGN

Database study.

SETTING

Community-based use of a portable sleep study device.

SUBJECTS AND METHODS

More than 77,000 patients who underwent a portable sleep study (SNAP Test, SNAP Labs Inc, Wheeling, Illinois) with a detailed, acoustical snoring analysis were matched to the Social Security Death Master File to establish mortality (1653 deaths matched). Snoring indices to include amount (snoring events per hour), volume (dB), and palatal versus nonpalatal snoring were correlated to mortality using stepwise multivariate logistic regression and survival analysis.

RESULTS

As expected, increasing age (odds ratio [OR] = 1.84; 95% confidence interval [CI], 1.76-1.93; P < .001), body mass index (BMI) (OR = 1.23; 95% CI, 1.18-1.28; P < .001), and male sex (OR = 1.38; 95% CI, 1.2-1.56; P < .001) were associated with increased all-cause mortality. The presence of increasing OSAS confounded the relationship between snoring and mortality. For patients without OSAS (apnea–hypopnea index [AHI] < 5) and with a BMI < 30 (n = 5955), increasing snoring was associated with an age- and sex-adjusted increase in mortality (OR = 1.16; 95% CI, 1.01-1.32; P = .034). For all patients, increasing nonpalatal snoring was associated with an increase in mortality (OR = 1.21; 95% CI, 1.09-1.35; P < .001) after adjustment for age, sex, BMI, and AHI. Survival analysis produced identical results to logistic regression.

CONCLUSION

In patients without OSAS and with a BMI less than 30, increasing snoring was associated with a significant increase in all-cause mortality. Nonpalatal snoring is associated with an increase in observed all-cause mortality controlling for age, sex, BMI, and AHI.

Sleep disordered breathing with excessive daytime sleepiness is a risk factor for mortality in older adults

STUDY OBJECTIVES

Excessive daytime sleepiness (EDS) is associated with increased mortality in older adults, yet sleep disordered breathing (SDB), a common cause of sleepiness, has not been shown to increase mortality in older adults. This study examined the relationship between daytime sleepiness, SDB, self-report sleep parameters, and mortality in older adults.

DESIGN

Longitudinal cohort study.

SETTING

Clinical and Translational Research Center, at-home testing.

PARTICIPANTS

289 study participants (age >65, no dementia or depression at the time of enrollment) classified as having EDS (n=146) or not (n=143).

MEASUREMENTS AND RESULTS

Study participants underwent in-lab polysomnography and multiple sleep latency testing at cohort inception. Survival analysis was conducted, with an average follow-up of 13.8 years. Excessive daytime sleepiness was associated with an unadjusted mortality hazard ratio of 1.5 (95% CI 1.1-2.0). The unadjusted mortality hazard ratio for study participants with both EDS and SDB (apnea-hypopnea index ≥20 events/h) was 2.7, 95% CI: 1.8-4.2. These findings persisted with an adjusted mortality hazard ratio of 2.3, 95% CI: 1.5-3.6 in the final model that included other covariates associated with increased mortality (sleep duration >8.5 h, self-reported angina, male gender, African American race, and age).

CONCLUSION

The presence of SDB is an important risk factor for mortality from excessive daytime sleepiness in older adults. In the presence of SDB at an AHI ≥20 events/h, EDS was associated with an increased all-cause mortality risk in older adults, even when adjusting for other significant risk factors, such as prolonged sleep duration. In older patients who had SDB without EDS, or EDS without SDB, there was no increased all-cause mortality rate.

Cardiovascular disease risk reduction with sleep apnea treatment

Cardiovascular diseases are the leading cause of death among adults in developed countries. An increase in prevalent cardiovascular risk factors (e.g., obesity, hypertension and diabetes) has led to a concerted effort to raise awareness of the need to use evidence-based strategies to help patients at risk of developing cardiovascular disease and to reduce their likelihood of suffering a stroke. Sleep apnea has emerged as an important risk factor for the development of cardiovascular disease. Epidemiologic and clinical evidence has prompted the American Heart Association to issue a scientific statement describing the need to recognize sleep apnea as an important target for therapy in reducing cardiovascular disease risks. This article examines evidence supporting associations of sleep apnea with cardiovascular disease and considers evidence suggesting cardiovascular risk reductions through sleep apnea treatment. Perspectives on emerging therapeutic approaches and promising areas of clinical and experimental research are also discussed.

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.

Adult obstructive sleep apnea/hypopnea syndrome: definitions, risk factors, and pathogenesis

The objectives of this article are to (1) understand how respiratory event definitions and syndrome threshold values affect prevalence estimates of obstructive sleep apnea in adults, (2) recognize important risk factors for obstructive sleep apnea in adults, and (3) understand current theories of the underlying mechanisms for airway obstruction during sleep.

Sleep apnea syndrome in a young cosmopolite urban adult population: risk factors for disease severity

PURPOSE

The purpose of this study is to investigate the risk factors for obstructive sleep apnea (OSA) in young patients from an urban European city with many migrants.

METHODS

The medical data of 2,343 patients referred for polysomnography from January 2007 till September 2009 were retrospectively reviewed in order to identify patients younger than 40 years with OSA and assess their characteristics.

RESULTS

One hundred twenty-one of the 2,093 patients (6%) referred for diagnostic polysomnography were younger than 40 years and had OSA. There were 17 women and 104 men. The race was Caucasian in 55% (67/121) and African in 42% (51/121). The median apnea-hypopnea index (AHI) was 39 in men and 23 in women (p < 0.01), 30 in Caucasians and 39 in Africans (p = 0.03). BMI was positively correlated to the AHI (correlation of 0.19, p = 0.04). Multiple regression modeling showed that African origin (p = 0.01), current smoking (p = 0.05), and neck circumference (p < 0.01) were predictors of AHI, independently of BMI, but not the presence of upper airway abnormalities (p = 0.75). Co-morbidities were frequent (hypertension, 20%; diabetes, 13%; hypercholesterolemia, 27%; depression, 13%; reflux and gastric ulcer, 13%; hypothyroidism, 5%; asthma, 9%), and were related to BMI (p = 0.02), nocturnal desaturation time (p = 0.02), and African origin (p = 0.024).

CONCLUSIONS

In patients aged <40 years and suffering from OSA, disease severity was associated with high BMI, large neck circumference, male sex, and African origin. After adjustment for BMI, African origin, tobacco use, and neck circumference remained predictors of high AHI. Neither upper airway abnormalities nor co-morbidities were found to be a risk factor for higher AHI in this group of young patients from a European city.

Clinical characteristics in two subgroups of obstructive sleep apnea syndrome in the elderly: comparison between cases with elderly and middle-age onset

BACKGROUND

Morbidity due to obstructive sleep apnea syndrome (OSAS) is increased in the elderly population. However, the clinical characteristics of OSAS in elderly patients have not been characterized conclusively. The aim of this study was to clarify differences in clinical characteristics of OSAS between patients with middle-age onset and elderly onset of OSAS.

METHODS

Patients with OSAS aged > or = 65 years were classified into groups according to age at first identification of respiratory pauses during sleep: a middle-age onset group (n = 32) where onset was at age < 50 years and an elderly onset group (n = 31) where onset was at age > or = 60 years. We compared demographic variables; polysomnographic variables; daytime sleepiness measures, including the multiple sleep latency test (MSLT) and the Epworth sleepiness scale (ESS); and adequate level of nasal continuous positive airway pressure (CPAP) between groups.

RESULTS

BMI and frequency of underlying cardiovascular disorder were lower in the elderly onset group than in the middle-age onset group. No significant differences in apnea-hypopnea index or percentage of the period showing O(2) desaturation were seen between groups. However, arousal index, maximal negative esophageal pressure value, and adequate nasal CPAP level were significantly smaller in the elderly onset group. Mean sleep latency on MSLT was longer, and ESS score was lower in the elderly onset group.

CONCLUSIONS

Compared with the middle-age onset group, the clinical significance of OSAS in the elderly onset group seemed to remain milder. This finding is possibly because of the smaller physiologic response to respiratory events.

Daytime sleepiness and its determining factors in Chinese obstructive sleep apnea patients

OBJECTIVE

The aim of this study was to characterize excessive daytime sleepiness (EDS) in a large cohort of Chinese patients with various severity of obstructive sleep apnea-hypopnea syndrome (OSAHS), and investigate its correlations with clinical/polysomnographic variables.

MATERIALS AND METHODS

A total of 1,035 consecutive Chinese patients with snoring (mean age ± SD 45 ± 15 years, BMI 26.6 ± 4.3 kg/m(2)) were examined by overnight polysomnography, and subjective EDS was assessed using the Epworth Sleepiness Scale (ESS).

RESULTS

The 1,035 patients were compared according to severity of sleep-disordered breathing: AHI <5 (primary snoring group or normal overall AHI) (24.1%), AHI 5-20 (mild OSAHS, 21.7%), AHI >20-40 (moderate OSAHS 16.5%), and AHI >40 (severe OSAHS 37.7%). ESS score progressively increased as the severity of OSAHS aggravated among these patients. More severe OSAHS patients were characterized by EDS, nocturnal hypoxemia, and disruption of sleep structure. Progressive worsening of nocturnal hypoxemia was observed from mild to severe OSAHS patients with a strong correlation with ESS score. The stepwise multiple regression analysis performed to evaluate the correlations of individual clinical and polysomnographic variables with the ESS score revealed that the ESS score significantly correlated with the oxygen desaturation index (ODI), apnea-hypopnea index (AHI), and body mass index (BMI), and ODI was the strongest determinant of ESS score.

CONCLUSION

EDS is correlated with the severity of OSAHS. More severe patients are characterized by higher ESS score, higher BMI, and progressive worsening of nocturnal hypoxemia. Nocturnal hypoxemia is a major determinant of EDS in Chinese OSAHS patients.

Early cardiovascular abnormalities in newly diagnosed obstructive sleep apnea

Obstructive sleep apnea (OSA) is associated with high cardiovascular morbidity and mortality. Recent studies have shown that it is associated with atherosclerosis and left ventricular dysfunction markers. The aim of this study was to assess the cardiovascular effects of OSA depending on its severity, in patients without clinically diagnosed cardiovascular disease. One hundred thirty newly diagnosed, nondiabetic OSA patients (mean age 49 +/- 10 years), without vasoactive treatment were included. They underwent clinical and ambulatory blood pressure measurements, echocardiography, carotid ultrasound examination, and a carotid-femoral pulse wave velocity (PWV) measurement. Seventy-five percent of the subjects were hypertensive according to the clinical or ambulatory measurement. More patients with the most severe forms (respiratory disturbance index >37/hour) had a nondipper profile (52% vs 34%; P = 0.025) and their left ventricular mass was higher (40 +/- 7 vs 36 +/- 8 g/m, p = 0.014). This last parameter was independently and inversely associated with mean nocturnal oxygen saturation (P = 0.004). PWV and carotid intima-media thickness did not differ between one OSA severity group to another, but the prevalence of carotid hypertrophy was higher when mean SaO(2) was below 93.5% (29.5 vs 16%; P = 0.05). Our study shows that in OSA patients without clinically diagnosed cardiovascular disease, there is a significant left ventricular and arterial effect, which is even more marked when OSA is severe.

[Why and how to diagnose sleep respiratory disorders?]

Gas exchange abnormalities occur firstly during sleep in restrictive and obstructive chronic respiratory failure. Nocturnal hypoxemia is often a revealing feature of a sleep-related hypoventilation/hypoxemia syndrome in patients who will have later a diurnal hypoxemia. On the other hand, sleep may induce breathing abnormalities in individuals without lung diseases, like in obstructive sleep apnea syndrome (OSAS). In OSAS, repeated closure and/or narrowing of the pharynx during sleep increases the inspiratory effort and induces sleep fragmentation. Intermittent hypoxemia is another consequence of the obstructive events in OSAS. Besides its direct consequences on sleep, OSAS is also associated with an increased risk of cardiovascular morbi-mortality. Reduced daytime alertness and cognitive functions are usually present in patients with sleep-disordered breathing. These features are believed to be related to both sleep fragmentation and nocturnal hypoxia/hypercapnia. Sleep-related hypoventilation/hypoxemia and pharyngeal obstructive events may occur together in patients with respiratory insufficiency, especially in obese and/or chronic obstructive pulmonary disease (COPD) subjects. A correct qualitative and quantitative assessment of sleep-disordered breathing may only be performed by recording specific physiological signals during sleep.

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.

Commentary from the Italian Association of Sleep Medicine on the AASM manual for the scoring of sleep and associated events: for debate and discussion

In 2007, the American Academy of Sleep Medicine (AASM) completed a new manual for the scoring of sleep and associated events. The AASM manual is divided into separate sections relative to the parameters reported for polysomnography. The present commentary, accomplished by a Task Force of the Italian Association of Sleep Medicine, focuses on sleep scoring data, arousal rules, movement and respiratory events. Comparisons with the previous Rechtschaffen and Kales system are detailed and a number of methodological weaknesses are pointed out. Major comments address the 30-s scoring epochs, the restrictive approach to arousals and EEG activating patterns, the incomplete quantification of motor events and the thresholds for the definition of hypopnea. Since the new AASM manual is an iterative process, proposals for discussion and re-examination of the agreed criteria with other national and international organizations are encouraged.

Medication adherence and persistence in severe obstructive sleep apnea

STUDY OBJECTIVE

The aim of this study was to compare 2 groups of patients with severe obstructive sleep apnea (OSA) who were taking medication for cardiovascular disease: those who were compliant with nasal continuous positive airway pressure (CPAP) treatment and those who refused treatment or were noncompliant with CPAP treament.

METHODS

In a cohort of 2158 patients with severe OSA (apnea-hypopnea index >30) a 2-year prospective longitudinal assessment of adherence and persistence with 3 medication categories (antihypertensives, statins, and antiplatelets) was carried out using the administrative database of the National Health Service. Medication adherence was evaluated by calculating the medication possession ratio (%MPR = days supplylactual days to refill x 100) for each drug. Medication persistency was defined as the proportion of subjects having filled a prescription in the last 30 days of the 2-year period. CPAP use was assessed at every follow-up visit after the treatment was prescribed. Medication adherence was compared between patients who had adequate CPAP adherence (> 4 h/day) and those who declined CPAP therapy or had discontinued CPAP due to an average use of less than 4 hours per day.

RESULTS

The average 2-year MPR for antihypertensives, statins, and antiplatelets was not different among patients who used CPAP (88%, 81%, 95%) or did not use CPAP (86%, 77%, 93%). Female sex and increased number of comorbidities were predictors of good medication adherence (MPR > 80%). The rates of persistence for the 3 studied medications after the 2-year observation period were not different between the 2 groups (patients with or without CPAP).

CONCLUSIONS

Medication adherence and persistence during a 2-year period for 3 well-known protective cardiovascular medications were not different in patients with severe OSA, whether or not they were treated with CPAP.

Continuous positive airway pressure treatment reduces mortality in patients with ischemic stroke and obstructive sleep apnea: a 5-year follow-up study

RATIONALE

Obstructive sleep apnea (OSA) is an independent risk factor for stroke, but little is known about the role of continuous positive airway pressure (CPAP) on mortality in patients with stroke.

OBJECTIVES

To analyze the independent impact of long-term CPAP treatment on mortality in patients with ischemic stroke.

METHODS

Prospective observational study in 166 patients with ischemic stroke. Sleep study was performed in all of them and CPAP treatment was offered in the case of moderate to severe cases. Patients were followed-up for 5 years to analyze the risk of mortality.

MEASUREMENTS AND MAIN RESULTS

Of 223 patients consecutively admitted for stroke, a sleep study was performed on 166 of them (2 mo after the acute event). Thirty-one had an apnea-hypopnea index (AHI) of less than 10; 39 had an AHI between 10 and 19, and 96 had an AHI of 20 or greater. CPAP treatment was offered when AHI was 20 or greater. Patients were followed up in our outpatient clinic at 1, 3, and 6 months, and for every 6 months thereafter for 5 years (prospective observational study). Mortality data were recorded from our computer database and official death certificates. The mean age of subjects was 73.3 +/- 11 years (59% males), and the mean AHI was 26 (for all patients with a predominance of obstructive events). Patients with an AHI of 20 or greater who did not tolerate CPAP (n = 68) showed an increase adjusted risk of mortality (hazards ratio [HR], 2.69; 95% confidence interval [CI], 1.32-5.61) compared with patients with an AHI of less than 20 (n = 70), and an increased adjusted risk of mortality (HR, 1.58; 95% CI, 1.01-2.49; P = 0.04) compared with patients with moderate to severe OSA who tolerated CPAP (n = 28). There were no differences in mortality among patients without OSA, patients with mild disease, and patients who tolerated CPAP.

CONCLUSIONS

Our results suggest that long-term CPAP treatment in moderate to severe OSA and ischemic stroke is associated with a reduction in excess risk of mortality.

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.

[The role of family physicians in the recognition and screening of obstructive sleep apnea]

Obstructive sleep apnea is the most frequent sleep disorder. The prevalence of sleep apnea in the general population is 2-4% and the main characteristic of the disease is the intermittent cessation or substantial reduction of airflow during sleep, caused by complete, or near complete upper airway obstruction. Decreased airflow is followed by oxygen desaturation and intermittent arousals. The clinical presentation of the disorder is complex. Loud snoring with breathing pauses and daytime sleepiness should raise the suspicion of sleep apnea, but we have to consider this disease if the patient has therapy resistant hypertension, heart failure, arrhythmias, stroke, depression or memory problems. Family physicians have an important role in recognizing sleep apnea. High risk patients can easily be identified by the main symptoms and using the Berlin sleep apnea questionnaire. These patients should be referred to a sleep laboratory for polysomnographic assessment and, if necessary, for further treatment.

Biology of peripheral blood cells in obstructive sleep apnea--the tip of the iceberg

Obstructive sleep apnea (OSA), a highly prevalent breathing disorder in sleep, characterized by intermittent and recurrent pauses in respiration, has emerged as an independent risk factor for cardiovascular morbidity and mortality. Accumulated evidence implicates Leukocyte-endothelial cell activation and adhesion as critical components that induce inflammation and injury to the vasculature resulting in the development of cardiovascular complications. Similar cellular interactions were described in conditions of ischemia/reperfusion, and various components of the metabolic syndrome as hypercholesterolemia and hypertension. The hallmark of sleep apnea--the multiple cycles of hypoxia/reoxygenation--promote oxidative stress and inflammation. These facilitate increased interactions of blood cells with endothelial cells, resulting in endothelial cell injury and dysfunction. Such events can promote atherosclerosis and the development of cardiovascular morbidities in OSA. However, inter-individual differences in response to intermittent hypoxia and activation of anti-inflammatory cytokine profiles in T lymphocytes can serve as protective mechanisms.

Prevalence of sleep disturbances in a cohort of older drivers

BACKGROUND

Lower levels of driving capacity in older persons are typically attributed to cognitive, visual, and/or physical impairments, with sleep disturbances rarely considered. This is in contrast to the general adult population for whom sleep disturbances are established risk factors for crashes. We thus set out to determine the prevalence of sleep disturbances in the form of insomnia symptoms, daytime drowsiness, and sleep apnea risk in a cohort of older drivers and to assess how these relate to self-reported driving capacity.

METHODS

Participants included 430 active drivers aged > or =70 years. Questionnaires measured self-reported insomnia symptoms (Insomnia Severity Index [ISI]), drowsiness (Epworth Sleepiness Scale [ESS]), apnea risk (Sleep Apnea Clinical Score [SACS]), driving mileage, driver self-ratings (overall and nighttime), and prior adverse driving events.

RESULTS

Mean age was 78.5 years, with 85% being male. Overall, 64% were dissatisfied with sleep patterns and 26% had an abnormal ISI (> or =8). A large proportion (60%) reported a moderate-to-high chance of dozing in the afternoon, and 19% had an abnormal ESS (> or =10). Habitual snoring was noted by 43%, with 20% at risk for sleep apnea (SACS > 15). Regarding driving, the most consistent finding was for lower levels of nighttime driver self-ratings in participants with insomnia symptoms or drowsiness. Lower levels of driving mileage were also noted but only with difficulty falling asleep. Otherwise, sleep disturbances were not associated with prior adverse driving events.

CONCLUSION

In our cohort of older drivers, insomnia symptoms and daytime drowsiness were prevalent and associated with lower levels of nighttime driver self-ratings. Although sleep apnea risk was also prevalent, it was not associated with self-reported driving capacity. These preliminary findings suggest that insomnia symptoms and drowsiness merit continued consideration as risk factors for lower levels of driving capacity in older persons, particularly given that effective interventions are available.

Sleep-disordered breathing in the usual lifestyle setting as detected with home monitoring in a population of working men in Japan

STUDY OBJECTIVES

To examine (1) the prevalence of home-monitored sleep-disordered breathing (SDB) and obstructive sleep apnea syndrome in a Japanese working population and (2) whether home monitoring with a type 3 portable monitor and actigraphy can produce reliable data to analyze SDB in usual lifestyles.

METHODS

A cross-sectional survey using a self-administered questionnaire was conducted on a group of employees at a wholesale company in Osaka, Japan. Examinations by physicians and by sleep monitoring were also performed. Unattended home cardiorespiratory (type 3) sleep studies with actigraphy were conducted for 2 nights to diagnose SDB in 322 subjects. From the baseline questionnaires and sleep diaries, participants were assessed to follow their usual lifestyles during the study (e.g., time in bed, alcohol intake).

RESULTS

Of 466 Japanese male employees, 396 responded to the questionnaire survey (85.0%). Results from 322 male employees aged 23 to 59 (43.8 +/- 8.4 years) were analyzed. Respiratory disturbance index (RDI), calculated from the type 3 portable monitors and actigraphy, was highly reliable with an intraclass correlation of 0.98 for interscorer reliability and with an intraclass correlation of 0.95 for night-to-night reliability. Prevalence of mild (5 < or = RDI < 15), moderate (15 < or = RDI < 30) and severe (RDI < or = 30) SDB in this population were 37.4%, 15.7%, and 6.6%, respectively. The prevalence of obstructive sleep apnea syndrome (RDI > or = 5 and Epworth Sleepiness Scale score > 10) was 17.6%.

CONCLUSIONS

The prevalence of moderate to severe SDB (RDI > or = 15) was 22.3% in this Japanese male working population aged 23 to 59, measured in participant's usual life settings. Unattended home monitoring with type 3 portable monitors and actigraphy was highly reliable and may be suitable for analyzing SDB in the usual lifestyle setting.

Cardiovascular disease and health-care utilization in snorers: a population survey

STUDY OBJECTIVES

We assessed the prevalence of self-reported snoring in the Hungarian population and established whether different types of snoring are associated with cardiovascular disorders and increased health-care utilization.

DESIGN

Cross-sectional study. Door-to-door survey.

SETTING

Nationally representative population in Hungary.

PARTICIPANTS

Interviews were carried out in the homes of 12,643 persons. We used the Hungarian National Population Register as the sampling frame and implemented a clustered, stratified sampling procedure. The study population represented 0.16% of the population over the age of 18 years according to age, sex, and 150 subregions of the country.

INTERVENTIONS

Not applicable.

MEASUREMENTS AND RESULTS

Thirty-seven percent of men and 21% of women reported loud snoring with breathing pauses. Hypertension, myocardial infarction, and stroke were reported by 26%, 3%, and 4% of the respondents, respectively. There was a significant increase in the prevalence of hypertension, myocardial infarction, and stroke in quiet and loud snorers, as compared with nonsnorers. Multivariate analysis showed an association between loud snoring and hypertension (odds ratio [OR]: 1.40, 95% confidence interval [CI]: 1.24-1.58), myocardial infarction (OR: 1.34, CI: 1.04-1.73), and stroke (OR: 1.67, CI: 1.32-2.11) after statistical adjustment for age, sex, body mass index, diabetes, level of education, smoking, and alcohol consumption. Loud snoring was also associated with measures of health-care use in both sexes.

CONCLUSIONS

Snoring is frequent in the Hungarian adult population, and loud snoring with breathing pauses, in contrast with quiet snoring, is associated with an increased risk of cardiovascular disease and increased health-care utilization.

[Arrhythmias in patients with obstructive sleep apnea]

The authors summarize the current knowledge on the types, prevalence, reasons, diagnosis and current therapy of arrhythmias occurring in patients with obstructive sleep apnea. Most of the patients with obstructive sleep apnea have nocturnal bradycardia (5-50%), paroxysmal tachyarrhythmia (atrial 35%; ventricular 0-15%), or both. The frequency of rhythm disturbances associated with the severity of the sleeping disorder. It is important to recognize the factors predisposing to arrhythmias and the early appropriate therapy of patients is essential, in order to protect patients from life threatening arrhythmias which may worsen the clinical outcome.