Glucose intolerance in Japanese patients with obstructive sleep apnea.

OBJECTIVE: Obstructive sleep apnea syndrome (OSAS) often accompanies obesity and diabetes mellitus. This study was performed to investigate the prevalence of glucose intolerance and to determine independent predictors for insulin resistance in patients with OSAS. METHODS: A cross-sectional study of 679 OSAS patients with an apnea-hypopnea index (AHI)>or=5/h and 73 controls subjects (AHI<5/h) was done in a tertiary university-based medical center. They were assessed by nocturnal polysomnography and underwent an oral glucose tolerance test. RESULTS: The prevalence of diabetes mellitus in OSAS patients was higher than that of the control group (25.9% vs. 8.2%, p<0.001) and 424 patients (62.4%) received a new diagnosis of impaired glucose tolerance or diabetes mellitus. The very severe OSAS group (AHI >or=45/h) had significantly higher homeostasis model assessment of insulin resistance (HOMA-IR) and HOMA beta-cell function than the other OSAS groups (AHI<45/h) and the control group. In a logistic regression model adjusting for potential confounders: age, AHI, minimum SpO(2) and body mass index (BMI), only BMI was associated with insulin resistance (HOMA-IR>3) (odds ratio: 1.272, 95% confidence interval 1.206-1.343, p<0.0001). CONCLUSION: Glucose intolerance was more common in patients with OSAS. Insulin resistance was associated not with AHI but rather with BMI.

Expenditure on health care in obese women with and without sleep apnea.

STUDY OBJECTIVES: To determine the effect of obesity and sleep apnea on health care expenditure in women over 10 years. DESIGN: Retrospective observational study SETTING: Tertiary university-based medical center PATIENTS AND CONTROLS: Three groups of age-matched women: 223 obese women with OSAS (body mass index: 39.3 +/- 0.6 kg/m2), and from the general population, 223 obese controls (BMI 36.3 +/- 0.4) and 223 normal weight controls (BMI 23.9 +/- 0.4). INTERVENTIONS: None. MEASUREMENTS AND RESULTS: We examined health care utilization in the 3 matched groups for the 10 years leading up to the documentation of OSAS. The mean physician fees and the number of physician visits were significantly higher in obese controls than in normal weight controls during the observed period. Physician fees and physician visits progressively increased in the 10 years before diagnosis in the OSAS cases and were significantly higher than in the matched obese controls. Physician fees, in Canadian dollars, one year before diagnosis in the OSAS cases were higher than in obese controls: $547.49 +/- 34.79 vs $246.85 +/- 20.88 (P<0.0001). More was spent for OSAS cases on physician fees for circulatory, endocrine and metabolic diseases, and mental disorders than the obese controls. Physician visits one year before diagnosis in the OSAS cases were more frequent than in the obese controls: 13.2 +/- 0.73 visits vs 7.26 +/- 0.49 visits (P<0.0001). CONCLUSIONS: Obese women are heavier users of health services than normal weight controls. Obese women with OSAS use significantly more health services than obese controls. Since OSAS imposes a greater financial burden, treatment of OSAS may reduce other comorbidities and lower overall medical costs.

Sleep apnea: clinical investigations in humans.

Sleep apnea syndrome (SAS), a common disorder, is characterized by repetitive episodes of cessation of breathing during sleep, resulting in hypoxemia and sleep disruption. The consequences of the abnormal breathing during sleep include daytime sleepiness, neurocognitive dysfunction, development of cardiovascular disorders, metabolic dysfunction, and impaired quality of life. There are two types of SAS: obstructive sleep apnea syndrome (OSAS) and central sleep apnea syndrome (CSAS). OSAS is a prevalent disorder in which there is snoring, repetitive apneic episodes, and daytime sleepiness. Anatomical conditions causing upper airway obstruction (obesity or craniofacial abnormalities such as retrognathia or micrognathia) can cause OSAS. CSAS, much less common than OSAS, is a disorder characterized by cessation of breathing which is caused by reduced respiratory drive from the central nervous system to the muscles of respiration. The latter condition is common in patients with heart failure and cerebral neurologic diseases. The diagnosis of SAS requires assessment of subjective symptoms and apneic episodes during sleep documented by polysomnography. Treatments of OSAS include continuous positive airway pressure (CPAP), oral appliances, and surgery; patients with CSAS are treated with oxygen, adaptive servo-ventilation, or CPAP. With assessment and treatment of the SAS, patients usually have resolution of their disabling symptoms, subsequently resulting in improved quality of life.

Healthcare utilization in women with obstructive sleep apnea syndrome 2 years after diagnosis and treatment.

UNLABELLED: SUBJECTIVE OBJECTIVES: To document healthcare utilization 2 years after diagnosis in women with obstructive sleep apnea syndrome (OSAS). DESIGN: Retrospective observational cohort study. SETTING: Tertiary university-based medical center. PATIENTS AND CONTROLS: Four hundred and fourteen women with OSAS were matched with 1404 women from the general population who served as controls. INTERVENTIONS: Patients were treated with continuous positive airway pressure (CPAP) or were recommended weight loss alone. MEASUREMENTS AND RESULTS: There were 231 treatment compliant (TC) patients, 91 patients not using CPAP (NCU), and 92 patients who were only recommended weight loss (WL). In the entire group, there was increase in fees of $123.43+/-$25.01 in the 2 years before diagnosis and a reduction of fees of $37.96+/-$21.35 in the 2 years after diagnosis (p < .0001). Physician claims increased in the 2 years before diagnosis by $111.22+/-31.35 in TC and by $152.77+/-59.55 in the NCU groups and then decreased in TC by $20.96+/-$26.60 (p < .01) and NCU by $72.20 +/-45.91 in the 2 years after diagnosis (p < .01). The fees in WL group did not change significantly. The number of clinic visits of the entire group increased in the 2 years before diagnosis by 2.32+/-0.43 and decreased over the next 2 years by 1.48+/-0.42 visits (p < .0001). There was an increase of clinic visits in the 3 subgroups in the 2 years before diagnosis (2.30+/-0.57 in TC, 2.55+/-0.99 in NCU, and 2.18+/-0.82 in WL groups) followed by a reduction of clinic visits over the next 2 years (1.56+/-0.55 fewer visits in TC [p < .0001], 1.70+/-0.90 in NCU [p < .01], and 1.04+/-0.90 in the WL group [p < .05] ). CONCLUSIONS: Healthcare utilization in women with OSAS increased in the years before sleep-clinic evaluation and then decreased in the following 2 years.

Metabolic syndrome in Japanese patients with obstructive sleep apnea syndrome.

We investigated the prevalence of metabolic syndrome in patients with obstructive sleep apnea syndrome (OSAS) referred to a tertiary university-based medical center. A cross-sectional study of patients with a definite diagnosis of OSAS was performed using new diagnostic criteria for metabolic syndrome that were designed for the Japanese population. Clinical features and comorbidities related to metabolic syndrome were compared between 819 patients with OSAS (719 men and 100 women) and 89 control subjects without OSAS. Metabolic syndrome was significantly more common in the patients with OSAS than in the controls (49.5% vs. 22.0% for men, p < 0.01; 32.0% vs. 6.7% for women, p < 0.01). Men with OSAS (apnea-hypopnea index [AHI] > or =5/h) had a higher risk of metabolic syndrome compared with controls (odds ratio [OR]: 3.47; 95% confidence interval [CI]: 1.84-6.53). There was a significantly increased risk of metabolic syndrome in men with moderate OSAS (AHI: 15-29.9/h) (OR: 2.83; 95% CI: 1.42-5.66) and men with severe OSAS (AHI > or =30/h) (OR: 5.09; 95% CI: 2.67-9.71). Women with OSAS (AHI> or =5/h) also had an increased risk of metabolic syndrome (OR: 6.59; 95% CI: 1.47-29.38), and the risk was significantly higher in women with severe OSAS (AHI > or =30/h) (OR 14.00; 95% CI: 2.93-66.82). Risk factors for metabolic syndrome differed by gender: in men, age, body mass index (BMI), and OSAS (AHI > or =15/h) were significantly associated with metabolic syndrome, whereas, in women, BMI was the only risk factor for metabolic syndrome. The increase of metabolic syndrome in Japanese OSAS patients suggests that this patient population is burdened with multiple risk factors for cardiovascular disease.

Adaptive servo-ventilation in patients with idiopathic Cheyne-Stokes breathing.

BACKGROUND: Cheyne Stokes Breathing (CSB), a form of central sleep apnea is often found in medical illnesses such as heart failure, stroke or renal failure. Adaptive servo-ventilation (ASV) has been reported to be an effective treatment of CSB in heart failure. However, there are no reports about using ASV for idiopathic CSB, which is not associated with heart failure or other serious medical problems. CASE SUMMARY: We evaluated three patients with idiopathic CSB and examined the feasibility of using ASV to treat them. The patients had a periodic breathing pattern resembling Cheyne-Stokes Breathing. During polysomnography, the abnormal breathing pattern was present while patients were both awake and asleep. The patients were first tested on continuous positive airway pressure (CPAP) and/or oxygen; however they did not respond well to either of these treatments. They were then assessed on ASV. The mean abnormal breathing events index decreased from 35.2 to 3.5 per hour of sleep on ASV. There was a significant reduction in the mean number of arousals caused by abnormal breathing events: from 18.5 to 1.1 per hour of sleep. After six to twelve months of using ASV, the patients had maintained significant improvement in subjective daytime alertness and mood. CONCLUSION: A trial of ASV for patients with idiopathic CSB is recommended if they do not have improvement in sleep respiration or daytime performance on CPAP and/or oxygen.

Utilization of healthcare resources in obstructive sleep apnea syndrome: a 5-year follow-up study in men using CPAP.

STUDY OBJECTIVES: Patients with untreated obstructive sleep apnea syndrome (OSAS) have higher healthcare utilization than matched controls. However, the long-term impact of continuous positive airway pressure (CPAP) use on healthcare utilization is unknown. DESIGN: Retrospective observational cohort study. SUBJECTS: There were 342 eligible men with OSAS and matched controls on whom there were utilization data for 5 years prior to initial OSAS diagnosis and for the 5 years on CPAP treatment of the cases. INTERVENTIONS: Patients were treated with CPAP. RESULTS: Patients with OSAS were typical cases (mean +/- SD): age, 48.2 +/- 0.6 years; body mass index, 35.6 +/- 0.4 kg/m2; Epworth Sleepiness Scale score, 14.2 +/- 0.3; apnea-hypopnea index, 47.1 +/- 1.8 events per hour. The number of physician visits were higher by 3.46 +/- 0.2 (95% confidence interval [CI]: 2.57 to 4.36) in cases in the year before diagnosis, compared with the fifth year before diagnosis, then decreased over the next 5 years by 1.03 +/- 0.49 (95% CI: -1.99 to -0.07)(P<.0001). Physician fees, in Canadian dollars, were higher by dollars 148.65 +/- dollars 27.27 (95% CI: 95.12 to 202.10) in cases in the year before diagnosis, compared with the fifth year before diagnosis, and then decreased over the next 5 years by dollars 13.92 +/- dollars 27.94(95%CI: -68.68 to 40.83)(P=.0009). Preexisting ischemic heart disease at the time of OSAS diagnosis predicted about a 5-fold increase in healthcare utilization between the second and fifth year of treatment. CONCLUSIONS: Treatment of OSAS reversed the trend of increasing healthcare utilization seen prior to diagnosis. Preexisting ischemic heart disease results in a negative impact on healthcare utilization. CPAP results in a long-term health benefit, as measured by the use of healthcare services.

Differences between men and women in the clinical presentation of patients diagnosed with obstructive sleep apnea syndrome.

STUDY OBJECTIVES: Obstructive sleep apnea syndrome (OSAS) results from recurrent episodes of breathing cessation during sleep. Epidemiologic studies have shown that OSAS is more prevalent in men than women (4% vs 2%). Previous studies have explored gender-related differences in upper airway anatomy and function, hormone physiology, and polysomnographic findings. The aim of this study is to assess differences in clinical presentation between women and men with OSAS. DESIGN: Retrospective chart review analysis. SETTING: Tertiary university-based medical center PARTICIPANTS: 130 randomly selected women with OSAS matched individually with 130 men with OSAS for age, body mass index, apnea-hypopnea index, and Epworth Sleepiness Scale score. INTERVENTIONS: N/A. MEASUREMENTS AND RESULTS: Data were obtained from questionnaires and in-laboratory polysomnographic studies. There were no differences between the genders for age (48.0 +/- 1.1 years [mean +/- SEM] for women vs 47.6 +/- 1.0 years for men), body mass index (40.4 +/- 0.7 kg/m2 for women vs 40.0 +/- 0.6 kg/m2 for men), apnea-hypopnea index (36.8 +/- 3.3/hour for women vs 36.0 +/- 3.0/hour for men), or Epworth Sleepiness Scale score (12.45 +/- 0.53 for women vs 12.84 +/- 0.47 for men). Although snoring and sleepiness were similarly common in women and men, women more often described their main presenting symptoms as insomnia (odds ratio: 4.20; 95% confidence interval: 1.54-14.26) and were much more likely to have a history of depression (odds ratio: 4.60; 95% confidence interval: 1.71-15.49) and hypothyroid disease (odds ratio: 5.60; 95% confidence interval: 2.14-18.57). Women presented less often with a primary complaint of witnessed apnea (odds ratio: 0.66; 95% confidence interval: 0.38-1.12), consumed less caffeine per day (3.3 cups in women vs 5.2 cups in men; P = .0001), and admitted to less alcohol consumption (odds ratio: 0.36; 95% confidence interval: 0.18-0.70). CONCLUSIONS: At the time of OSAS diagnosis, women with OSAS are more likely to be treated for depression, to have insomnia, and to have hypothyroidism than are men with the same degree of OSAS.

Experience in using split-day studies for suspected obstructive sleep apnea syndrome.

BACKGROUND: Because in many locations the demand for sleep studies exceeds resources, we evaluated the utility of split-day in-laboratory studies (SDS) in highly selected patients. METHODS: We studied 100 eligible cases: 68 males (age 48.6+/-1.3 [standard error, se] years, body mass index (BMI): 32.6+/-0.8 kg/m(2)) and 32 females (age 50.9+/-2.4 years, BMI: 36.3+/-1.3 kg/m(2)) with severe subjective sleepiness (Epworth sleepiness scale: ESS 16) and suspected obstructive sleep apnea syndrome (OSAS). RESULTS: There were 86 conclusive studies that yielded both a diagnosis and sufficient information for management (86.0%) and 14 inconclusive studies that did not yield sufficient information for management (14.0%). In six cases (6.0%) with an inconclusive study a diagnosis was made, however, no titration data was obtained. Thus a definitive diagnosis was obtained in 92.0% of all cases. Those with inconclusive studies had additional assessment, and eight of them ultimately had a final diagnosis of a sleep breathing disorder (SBD) and six had another sleep disorder: four had narcolepsy, one had a movement disorder, one had sleep deprivation. Thus there were six patients (6.0%) in whom SDS yielded only an SBD diagnosis but there was insufficient data for titration; two patients (2.0%) who ultimately had severe OSAS who were not diagnosed on SDS. CONCLUSIONS: SDS was found to be useful in the evaluation and treatment of highly selected patients with severe daytime sleepiness (ESS 16) and suspected OSAS.

Long-term treatment of sleep breathing disorder in a patient with Huntington's disease.

Huntington's disease (HD) is an autosomal dominant neurodegenerative disorder. An association with sleep breathing disorder has not previously been established in the literature. We report the case of a 45-year-old woman with HD, presenting with snoring and observed apnea. Polysomnography showed obstructive sleep apnea with an apnea-hypopnea index (AHI) of 6.6 per hour including events up to 57 s long during rapid eye movement (REM) sleep. A trial of continuous positive airway pressure (CPAP) resulted in significant improvement in sleep structure, nocturnal respiration, daytime alertness, and subjective memory. Snoring, apneas, and respiratory arousals were abolished on CPAP. HD patients may suffer from sleep breathing disorder, and in spite of potential chorea, CPAP is feasible and may significantly improve their quality of life.

Increasing obesity trends in patients with sleep-disordered breathing referred to a sleep disorders center.

STUDY OBJECTIVES: The prevalence of sleep-related breathing disorders (SBD) is high and may be rising because of the increasing prevalence of obesity. We investigated the obesity trends over 9 years in patients referred to a sleep disorders center suspected of having SBD. PATIENTS: There were 5163 new patients (3679 men and 1484 women) who were referred to sleep disorders centee for an assessment of SBD from January 1995 to May 2004. MEASUREMENTS AND RESULTS: During the entire period, the mean body mass index (BMI) at time of referral was 32.2 +/- 0.1 kg/m2 (+/- SEM) (95% confidence interval [CI]:32.0-32.4) in men versus 34.5 +/- 0.2 kg/m2 (95% CI: 34.1-35.0) in women (p < .0001). Mean age and BMI were calculated for each 3-month period starting in January 1995. Regression analysis using a generalized linear model was performed to determine the relationship between BMI and the time when the patients were referred, for both sexes. The annual increase in mean BMI was 0.17 (95% CI: 0.10-0.24) for men (p < .0001) and 0.34 (95% CI: 0.13-0.54) for women (p = .002). There was no relationship between age at referral and BMI in either sex. There was a significant positive correlation between year of referral and BMI for both sexes: p < .0001, r2 = 0.40 for men, p = .002, r2 = 0.24 for women. The average female patient was 3.4 BMI units heavier over the 9-year period, while the average male patient was 1.7 BMI units heavier. CONCLUSIONS: The BMI in patients referred to a sleep disorders center for an assessment of SBD has increased significantly over 9 years. Recent obesity trends may contribute to the increase in the number of patients with SBD.

Sleep-disordered breathing in patients with idiopathic cardiomyopathy.

BACKGROUND: Sleep-disordered breathing may adversely affect heart function, and thereby contribute to the progression of heart failure. A study was undertaken in patients with idiopathic cardiomyopathy to document the characteristics of sleep-disordered breathing. METHODS AND RESULTS: Thirty-five patients with a diagnosis of idiopathic cardiomyopathy, comprising 20 patients with dilated cardiomyopathy (DCM) and 15 patients with hypertrophic cardiomyopathy (HCM), underwent overnight polysomnography. Of these 35, 16 (80%) of the DCM patients and 7 (47%) of the HCM patients had sleep-disordered breathing. Central sleep apnea-hypopnea syndrome (CSAHS) was seen in 10 DCM patients, but not in the HCM patients, and obstructive sleep apnea-hypopnea syndrome (OSAHS) was seen in 6 DCM patients and 7 HCM patients. CSAHS was seen in DCM patients with a low left ventricular ejection fraction. HCM patients with OSAHS had a significantly greater body mass index (BMI) than those without OSAHS and CSAHS (27.6 +/- 3.8 vs 22.0 +/- 4.0 kg/m2, p<0.05). DCM patients with OSAHS had a larger BMI than those with CSAHS (29.3 +/- 5.8 vs 24.2 +/- 4.0 kg/m2, p<0.05) and those without OSAHS and CSAHS (29.3 +/- 5.8 vs 21.3 +/- 3.1 kg/m2, p<0.05). CONCLUSIONS: Sleep-disordered breathing is common in patients with idiopathic cardiomyopathy; half of DCM patients had CSAHS, which was closely associated with obesity.

Pulmonary hypertension in patients with severe obstructive sleep apnea.

Thirty-seven patients (35 men and two women) with obstructive sleep apnea-hypopnea syndrome (OSAHS) without any known cardiovascular and lung diseases were examined by Doppler echocardiography. Eight of the 37 (21.6%) patients experienced daytime pulmonary hypertension (PH), and all of them had severe OSAHS with an apnea-hypopnea index of > 30. The study suggested that one-third of patients with severe OSAHS had daytime PH.

Falling asleep while driving and automobile accidents among patients with obstructive sleep apnea-hypopnea syndrome.

Among 448 patients with obstructive sleep apnea-hypopnea syndrome (OSAHS), 40 patients (8.9%) had been involved in one or more automobile accidents during the preceding 5 years. The main cause of these accidents was falling asleep while driving. Excessive sleepiness during driving was associated with an Epworth sleepiness scale (ESS) score of > 11 and/or an apnea-hypopnea index (AHI) of > 15. The automobile accident rate among 182 patients with severe OSAHS (AHI > 30) was significantly higher than the rate among 106 simple snorers (AHI < 5). Although four of the simple snorers were involved in automobile accidents, their ESS scores were all very high (15 or more).