background Previous studies have suggested that the obstructive sleep apnea syndrome may be an important risk factor for stroke. It has not been determined, however, whether the syndrome is independently related to the risk of stroke or death from any cause after adjustment for other risk factors, including hypertension. methods In this observational cohort study, consecutive patients underwent polysomnography, and subsequent events (strokes and deaths) were verified. The diagnosis of the obstructive sleep apnea syndrome was based on an apnea–hypopnea index of 5 or higher (five or more events per hour); patients with an apnea–hypopnea index of less than 5 served as the comparison group. Proportional-hazards analysis was used to determine the independent effect of the obstructive sleep apnea syndrome on the composite outcome of stroke or death from any cause. results Among 1022 enrolled patients, 697 (68 percent) had the obstructive sleep apnea syndrome. At baseline, the mean apnea–hypopnea index in the patients with the syndrome was 35, as compared with a mean apnea–hypopnea index of 2 in the comparison group. In an unadjusted analysis, the obstructive sleep apnea syndrome was associated with stroke or death from any cause (hazard ratio, 2.24; 95 percent confidence interval, 1.30 to 3.86; P=0.004). After adjustment for age, sex, race, smoking status, alcohol-consumption status, body-mass index, and the presence or absence of diabetes mellitus, hyperlipidemia, atrial fibrillation, and hypertension, the obstructive sleep apnea syndrome retained a statistically significant association with stroke or death (hazard ratio, 1.97; 95 percent confidence interval, 1.12 to 3.48; P=0.01). In a trend analysis, increased severity of sleep apnea at baseline was associated with an increased risk of the development of the composite end point (P=0.005). conclusions The obstructive sleep apnea syndrome significantly increases the risk of stroke or death from any cause, and the increase is independent of other risk factors, including hypertension.

https://www.nejm.org/doi/pdf/10.1056/NEJMoa043104

Obstructive sleep apnea as a risk factor for stroke and death.

The aim of this updated statement is to provide comprehensive and timely evidence-based recommendations on the prevention of stroke among individuals who have not previously experienced a stroke or transient ischemic attack. Evidence-based recommendations are included for the control of risk factors, interventional approaches to atherosclerotic disease of the cervicocephalic circulation, and antithrombotic treatments for preventing thrombotic and thromboembolic stroke. Further recommendations are provided for genetic and pharmacogenetic testing and for the prevention of stroke in a variety of other specific circumstances, including sickle cell disease and patent foramen ovale.

Guidelines for the Primary Prevention of Stroke A Guideline for Healthcare Professionals From the American Heart Association/American Stroke Association

These practice parameters are an update of the previously-published recommendations regarding the indications for polysomnography and related procedures in the diagnosis of sleep disorders. Diagnostic categories include the following: sleep related breathing disorders, other respiratory disorders, narcolepsy, parasomnias, sleep related seizure disorders, restless legs syndrome, periodic limb movement sleep disorder, depression with insomnia, and circadian rhythm sleep disorders. Polysomnography is routinely indicated for the diagnosis of sleep related breathing disorders; for continuous positive airway pressure (CPAP) titration in patients with sleep related breathing disorders; for the assessment of treatment results in some cases; with a multiple sleep latency test in the evaluation of suspected narcolepsy; in evaluating sleep related behaviors that are violent or otherwise potentially injurious to the patient or others; and in certain atypical or unusual parasomnias. Polysomnography may be indicated in patients with neuromuscular disorders and sleep related symptoms; to assist in the diagnosis of paroxysmal arousals or other sleep disruptions thought to be seizure related; in a presumed parasomnia or sleep related seizure disorder that does not respond to conventional therapy; or when there is a strong clinical suspicion of periodic limb movement sleep disorder. Polysomnography is not routinely indicated to diagnose chronic lung disease; in cases of typical, uncomplicated, and noninjurious parasomnias when the diagnosis is clearly delineated; for patients with seizures who have no specific complaints consistent with a sleep disorder; to diagnose or treat restless legs syndrome; for the diagnosis of circadian rhythm sleep disorders; or to establish a diagnosis of depression.

/pdf/practice-parameters-for-the-indications-for-polysomnography-79szzyhm7q.pdf

Practice parameters for the indications for polysomnography and related procedures: an update for 2005.

Background Obstructive sleep apnea (OSA) is a major risk factor for perioperative adverse events. However, no screening tool for OSA has been validated in surgical patients. This study was conducted to develop and validate a concise and easy-to-use questionnaire for OSA screening in surgical patients. Methods After hospital ethics approval, preoperative patients aged 18 yr or older and without previously diagnosed OSA were recruited. After a factor analysis, reliability check, and pilot study; four yes/no questions were used to develop this screening tool. The four questions were respectively related to snoring, tiredness during daytime, observed apnea, and high blood pressure (STOP). For validation, the score from the STOP questionnaire was evaluated versus the apnea-hypopnea index from monitored polysomnography. Results The STOP questionnaire was given to 2,467 patients, 27.5% classified as being at high risk of OSA. Two hundred eleven patients underwent polysomnography, 34 for the pilot test and 177 for validation. In the validation group, the apnea-hypopnea index was 20 +/- 6. The sensitivities of the STOP questionnaire with apnea-hypopnea index greater than 5, greater than 15, and greater than 30 as cutoffs were 65.6, 74.3, and 79.5%, respectively. When incorporating body mass index, age, neck circumference, and gender into the STOP questionnaire, sensitivities were increased to 83.6, 92.9, and 100% with the same apnea-hypopnea index cutoffs. Conclusions The STOP questionnaire is a concise and easy-to-use screening tool for OSA. It has been developed and validated in surgical patients at preoperative clinics. Combined with body mass index, age, neck size, and gender, it had a high sensitivity, especially for patients with moderate to severe OSA.

Stop questionnaire: a tool to screen patients for obstructive sleep apnea

Sleep apnea and cardiovascular disease: an American Heart Association/American College of Cardiology Foundation Scientific Statement from the American Heart Association Council for High Blood Pressure Research Professional Education Committee, Council on Clinical Cardiology, Stroke Council, and Council on Cardiovascular Nursing.

Although sleep apnea is common, it often goes undiagnosed in primary care encounters. The Berlin Questionnaire was found to be a means of identifying patients who are likely to have sleep apnea.

Using the Berlin Questionnaire To Identify Patients at Risk for the Sleep Apnea Syndrome

Prevalence of Symptoms and Risk of Sleep Apnea in Primary Care

Background and Purpose —Epidemiological data link heavy snoring to an increased risk for stroke, an association often ascribed to hypertension and/or sleep apnea. The aim of this study was to determine whether obstructive hypopneas, central apneas, or obstructive apneas during sleep alter blood flow of the middle cerebral artery (MCA).

Methods —Doppler sonography of the MCA was performed in conjunction with nightly polysomnography in 11 men and one woman.

Results —A significant decline in blood flow occurred in 76% (169/223) of obstructive hypopneas and in 80% (98/123) of obstructive apneas, compared with only 14% (13/96) of central apneas ( P ≤.0001). While duration of events was not significantly different, MCA blood flow reductions were associated only with the duration of the obstructive hypopneas ( P ≤.01) and not with the duration of central ( P =.17) or obstructive ( P =.07) apneas. The magnitude of fall in arterial oxygen saturation from baseline correlated with a reduced blood flow with obstructive hypopneas but not with obstructive or central apneas.

Conclusions —With obstructive hypopneas and obstructive apneas, MCA blood flow is more often decreased in comparison to central apneas. MCA blood flow reductions occur with longer obstructive hypopneas and with those hypopneas with greater falls in oxygen saturation. These observations indicate pathophysiology relevant to an increased risk for stroke in heavy snorers and patients with obstructive hypopneas and apneas.

Blood flow of the middle cerebral artery with sleep-disordered breathing: correlation with obstructive hypopneas.

Background: Low levels of sex hormones, especially progesterone, are suspected as a risk factor for sleep-disordered breathing (SDB). Objective: To test the hypothesis that serum levels of progesterone, estradiol, and 17-OH progesterone are lower in those women with clinically significant SDB. Design: Clinical cohort of convenience. Setting: University Hospital Sleep Laboratory. Methods: We investigated sleep and breathing parameters and serum levels of sex hormones in 53 consecutive women (ages 24 to 72 years) being evaluated for symptoms of daytime sleepiness. Analysis of hormonal status by specific radioimmunoassays and fluorescence immunoassays was done from blood samples taken after an overnight polysomnography. Results: Across the cohort, taking account of age and cycle time or postmenopausal status, those with an apnea-hypopnea index (AHI) greater than 10/hrs of sleep had significantly lower levels of 17-OH progesterone, progesterone, and estradiol than those with an AHI less than 10. Conclusion: We conclude that reductions in female sex hormones are associated with an increased probability of SDB in women with daytime sleepiness.

Women with sleep apnea have lower levels of sex hormones.

BACKGROUND: The aim of this study was to determine in an open trial if physical exercise in sleep apnea patients is safe and/or influences respiratory disturbance index (RDI). METHODS: After being treated 3 months or more with nasal CPAP for moderate to severe sleep apnea syndrome, eleven patients (1 female, 10 male, mean age 52.2 years) began a six-month period of supervised physical exercise twice a week, 2 hours each time. Before and after this period a Polysomnography without CPAP was recorded, along with a bicycle exercise test with lactate profile, echocardiography, body-weight, and body-height measurement. RESULTS: No adverse effects or cardiopulmonary problems were observed. There was no significant change in body weight with physical training; no significant difference in either min SaO2 nor mean SaO2; and no significant improvement in fitness. No adverse cardiopulmonary effects or problems were observed. There was a decrease of the RDI from 32.8 to 23.6 (p < 0.05), without a significant change in the REM-sleep portion of total sleep time (TST), NREM sleep, or TST. CONCLUSIONS: A prescription for mild to moderate exercise is safe in the management of sleep apnea, and, even in the absence of a fitness improvement, there occurred a decrease in RDI without a change in sleep architecture.

Nikolaus C. Netzer

Papers

Using the Berlin Questionnaire To Identify Patients at Risk for the Sleep Apnea Syndrome

Prevalence of Symptoms and Risk of Sleep Apnea in Primary Care

Blood flow of the middle cerebral artery with sleep-disordered breathing: correlation with obstructive hypopneas.

Women with sleep apnea have lower levels of sex hormones.

Physical Exercise as an Adjunct Therapy in Sleep Apnea-An Open Trial.