Restoring the Salivary Cortisol Awakening Response Through Nasal Continuous Positive Airway Pressure Therapy in Obstructive Sleep Apnea

Partial and largely conflicting data are currently available on the interplay between obstructive sleep apnea (OSA) and hypothalamus-pituitary-adrenal axis (HPA) activity in adult obese men. This study was performed to evaluate the daily trajectories of salivary cortisol, specifically with respect to the salivary cortisol awakening response (CAR), a common method used to assess HPA axis activity. The main findings of this study were that adult male obese subjects who were newly diagnosed with severe OSA showed the following: (1) a flattening of the CAR; (2) levels of cortisol at awakening that were lower than those of the controls; and (3) maintenance of the physiological circadian activity of the HPA axis, with the highest hormone concentrations produced in the morning and the lowest in the evening. This study was also designed to investigate the effects of 3 and 6 mos of treatment with continuous airways positive pressure (CPAP). CPAP use resulted in a significant recovery of the sleep patterns disrupted by OSA; moreover, mild neuropsychological signs of depression and anxiety in severe OSA patients were concomitantly progressively improved by CPAP treatment. Furthermore, this study reports that 3 and 6 mos of CPAP therapy restored the presence of CAR and was able to significantly reduce the difference in the morning cortisol levels between the OSA and control groups. In conclusion, we report here that compared with obese nonapneic matched controls, OSA patients present a dysregulation of HPA axis activity, as shown by the flattening of the diurnal pattern of cortisol production in response to repeated challenge due to hypoxia and sleep fragmentation. This dysregulation was especially detectable in the first hour after awakening and restored after 3 and 6 mos of treatment with CPAP.     

Effect of Continuous Positive Airway Pressure on Adiponectin in Patients with Obstructive Sleep Apnea: A Meta-Analysis

Objective

Obstructive sleep apnea (OSA) has been suggested to be associated with low levels of adiponectin. Continuous positive airway pressure (CPAP) is the gold standard treatment for OSA; however, previous studies assessing the effect of CPAP on adiponectin in patients with OSA yielded conflicting results. The present meta-analysis was performed to determine whether CPAP therapy could increase adiponectin levels.

Methods

Two reviewers independently searched PubMed, Cochrane library, Embase and Web of Science before February 2015. Information on characteristics of subjects, study design and pre- and post-CPAP treatment of serum adiponectin was extracted for analysis. Standardized mean difference (SMD) was used to analyze the summary estimates for CPAP therapy.

Results

Eleven studies involving 240 patients were included in this meta-analysis, including ten observational studies and one randomized controlled study. The meta-analysis showed that there was no change of adiponectin levels before and after CPAP treatment in OSA patients (SMD = 0.059, 95% confidence interval (CI) = −0.250 to 0.368, z = 0.37, p = 0.710). Subgroup analyses indicated that the results were not affected by age, baseline body mass index, severity of OSA, CPAP therapy duration, sample size and racial differences.

Conclusions

This meta-analysis suggested that CPAP therapy has no impact on adiponectin in OSA patients, without significant changes in body weight. Further large-scale, well-designed long-term interventional investigations are needed to clarify this issue.     

Continuous Positive Airway Pressure Treatment Reduces Mortality in Elderly Patients with Moderate to Severe Obstructive Severe Sleep Apnea: A Cohort Study

Obstructive sleep apnea (OSA) is much more prevalent in older people than in middle-aged or young populations, and has been associated with cardiovascular disease. Continuous positive airway pressure (CPAP) is the first-line therapy for OSA, but its long-term clinical benefit in the elderly is unclear. Here, we carried out a prospective cohort study to explore the survival rate and incidence of cardiovascular events in elderly patients with moderate to severe OSA who did or did not receive CPAP treatment. The study included 130 patients (104 male, 26 female; mean age: 77.8 ± 6.2 years) who were followed up for a mean of 5 ± 2.54 years (range, 1–8 years). Thirty-six patients received CPAP and 88 had no CPAP. The results showed that mortality in the untreated group (21.6%) was significantly higher than in the CPAP group (5.6%). Kaplan–Meier survival analysis showed that the survival rate in the CPAP group was 94.4%, which was markedly higher than the rate of 78.4% in the untreated group. The incidence of cardiovascular events was 13.9% in the CPAP group and 55.7% in the untreated group. The present study provides evidence that CPAP can reduce mortality in older patients with moderate to severe OSA, and lead to a good long-term prognosis. The study also indicates that death in older OSA patients is associated with cardiovascular disease and diabetes.     

Socio-Economic Status: A Barrier to Access to Mandibular Advancement Device Therapy for Patients with Obstructive Sleep Apnea Syndrome in France

Background

Obstructive sleep apnea syndrome (OSAS) is a major public health problem which affects between 5 to 10% of the general population. OSAS is known to be associated with high rates of morbidity and mortality mainly due to cardiovascular diseases and traffic accidents. The burden of illness is high for the individual and society. There are 2 treatment options for OSAS, Continuous Positive Airway Pressure (CPAP) and Mandibular Advancement Device therapy (MAD). CPAP is known to be an effective but very constraining treatment. Patients are usually poorly adherent. MAD is a more recent treatment easier to use and consequently better tolerated, but MAD can only be prescribed to patients with satisfactory oral hygiene. Oral health constitutes a real issue particularly among underprivileged groups in France. Through this link, the question of whether low socio-economic status constitutes a barrier to access to care for patients with OSAS is raised.

Methods and Principal Findings

In a multicenter prospective cohort of 2822 consecutive OSAS patients in whom MAD has been proposed as an alternative to CPAP between May 15, 2007 and December 1st, 2014, we identified the factors that lead to a patient diagnosed with OSAS to be treated by MAD instead of CPAP. A logistic regression was performed using a stepwise forward procedure. The main outcome of the study was that treatment by MAD was significantly associated with both educational attainment, as determined by the age at which the patient left full-time education, ≥18 years compared with <18 (adjusted odds ratio (aOR): 1.64, 95% CI 1.23 to 2.20), and the patient''s occupational category. Executives and higher intellectual professions, intermediate professions, technicians, foremen and employees were significantly more likely to be treated by MAD than workers (aOR: 2.21, 95% CI 1.88 to 2.58; aOR: 1.74, 95% CI 1.15 to 2.63; aOR: 1.96, 95% CI 1.11 to 3.47, respectively).

Conclusions

Overall, these results suggest that low socio-economic status constitutes a barrier to access to MAD for patients with OSAS in France. MAD use in patients with OSAS highlights inequalities in health care access.     

Efficacy of Continuous Positive Airway Pressure on Testosterone in Men with Obstructive Sleep Apnea: A Meta-Analysis

Objective

To evaluate the efficacy of continuous positive airway pressure (CPAP) on serum testosterone in men with obstructive sleep apnea (OSA).

Methods

Two reviewers independently searched PubMed, Cochrane library, Embase and Web of Science before June 2014. Information on characteristics of subjects, study design, pre- and post-CPAP treatment of serum total testosterone, free testosterone and sexual hormone blinding protein (SHBG) was extracted for analysis.

Results

A total of 7 studies with 9 cohorts that included 232 men were pooled into meta-analysis. There was no change of total testosterone levels before and after CPAP treatment in OSA men (standardized mean difference (SMD) = −0.14, 95%CI: −0.63 to 0.34, z = 0.59, p = 0.558), even subdivided by CPAP therapeutic duration (>3 months). Meanwhile, no significant differences in free testosterone and SHBG were detected after CPAP treatment (SMD =  0.16, 95%CI: −0.09 to 0.40, z = 1.25, p = 0.211 and SMD = −0.58, 95%CI: −1.30 to 0.14, z = 1.59, p = 0.112, respectively).

Conclusion

CPAP has no influence on testosterone levels in men with OSA, further large-scale, well-design interventional investigation is needed.     

Relationship between Aldosterone and the Metabolic Syndrome in Patients with Obstructive Sleep Apnea Hypopnea Syndrome: Effect of Continuous Positive Airway Pressure Treatment

Background

Metabolic syndrome (MS) occurs frequently in patients with obstructive sleep apnea-hypopnea syndrome (OSAHS). We hypothesized that aldosterone levels are elevated in OSAHS and associated with the presence of MS.

Methods

We studied 66 patients with OSAHS (33 with MS and 33 without MS) and 35 controls. The occurrence of the MS was analyzed according to the National Cholesterol Education Program Adult Treatment Panel III (NCEP ATP III) clinical criteria. Measurements of plasma renin activity (PRA), aldosterone, aldosterone:PRA ratio, creatinine, glucose, triglycerides, cholesterol and HDL cholesterol were obtained at baseline and after CPAP treatment.

Results

Aldosterone levels were associated with the severity of OSAHS and higher than controls (p = 0.046). Significant differences in aldosterone levels were detected between OSAHS patients with and without MS (p = 0.041). A significant reduction was observed in the aldosterone levels in patients under CPAP treatment (p = 0.012).

Conclusion

This study shows that aldosterone levels are elevated in OSAHS in comparison to controls, and that CPAP therapy reduces aldosterone levels. It also shows that aldosterone levels are associated with the presence of metabolic syndrome, suggesting that aldosterone excess might predispose or aggravate the metabolic and cardiovascular complications of OSAHS.

Trial registration

The study is not a randomized controlled trial and was not registered.

What is the key question?

Are aldosterone levels elevated in patients with obstructive sleep apnea-hypopnea syndrome (OSAHS), and associated with the presence of metabolic syndrome (MS)?

What is the bottom line?

Current data indicate that OSAHS is highly associated with MS. The underlying mechanistic links between OSAHS and MS are not well delineated to date.There is a close relationship between the Renin-Angiotensin-Aldosterone system and hypertension, and recent evidence involves aldosterone in the pathogenesis of MS.

Why read on?

These findings show that aldosterone levels are elevated in OSAHS in comparison to controls, and continuous positive airway pressure (CPAP) therapy reduces aldosterone levels. They also show that aldosterone levels are associated with the presence of metabolic syndrome, suggesting a potential role of aldosterone excess in the development of metabolic and cardiovascular complications in patients with OSAHS.

What is the bottom line?

Current data indicate that OSAHS is highly associated with MS. The underlying mechanistic links between OSAHS and MS are not well delineated to date.There is a close relationship between the Renin-Angiotensin-Aldosterone system and hypertension, and recent evidence involves aldosterone in the pathogenesis of MS.

Why read on?

These findings show that aldosterone levels are elevated in OSAHS in comparison to controls, and continuous positive airway pressure (CPAP) therapy reduces aldosterone levels. They also show that aldosterone levels are associated with the presence of metabolic syndrome, suggesting a potential role of aldosterone excess in the development of metabolic and cardiovascular complications in patients with OSAHS.     

经鼻高流量氧疗对阻塞性睡眠呼吸暂停综合征患者的临床疗效研究

目的:探讨经鼻高流量氧疗对阻塞性睡眠呼吸暂停综合征患者的临床疗效。方法:选择2013年7月至2017年7月我院接诊的80例急阻塞性睡眠呼吸暂停综合征患者进行研究,通过随机数表法分为观察组(n=45)和对照组(n=35)。观察组采用经鼻高流量氧疗进行治疗,对照组采用无创正压通气进行治疗,比较两组临床疗效、夜间呼吸暂停时间、呼吸暂停低通气指数(AHI)、总睡眠时间、醒觉时间、血氧饱和度、治疗前后血压、高敏C反应蛋白(hs-CRP)、低密度脂蛋白(LDL)、总胆固醇(TC)水平及生活质量评分的变化。结果:观察组患者治疗后有效率为88.89%,显著高于对照组(71.43%,P0.05)。治疗后,观察组夜间最低血氧饱和度、总睡眠时间、醒觉时间、生活质量评分均明显高于对照组,AHI、收缩压、舒张压、平均动脉压、血清hs-CRP、LDL以及TC水平均显著低于对照组(P0.05)。结论:经鼻高流量氧疗用于阻塞性睡眠呼吸暂停综合征患者的临床疗效明显优于无创正压通气进行治疗,其可显著改善患者的临床症状,提高患者的生活质量。     

Brain Structure Network Analysis in Patients with Obstructive Sleep Apnea

Childhood obstructive sleep apnea (OSA) is a sleeping disorder commonly affecting school-aged children and is characterized by repeated episodes of blockage of the upper airway during sleep. In this study, we performed a graph theoretical analysis on the brain morphometric correlation network in 25 OSA patients (OSA group; 5 female; mean age, 10.1 ± 1.8 years) and investigated the topological alterations in global and regional properties compared with 20 healthy control individuals (CON group; 6 females; mean age, 10.4 ± 1.8 years). A structural correlation network based on regional gray matter volume was constructed respectively for each group. Our results revealed a significantly decreased mean local efficiency in the OSA group over the density range of 0.32–0.44 (p < 0.05). Regionally, the OSAs showed a tendency of decreased betweenness centrality in the left angular gyrus, and a tendency of decreased degree in the right lingual and inferior frontal (orbital part) gyrus (p < 0.005, uncorrected). We also found that the network hubs in OSA and controls were distributed differently. To the best of our knowledge, this is the first study that characterizes the brain structure network in OSA patients and invests the alteration of topological properties of gray matter volume structural network. This study may help to provide new evidence for understanding the neuropathophysiology of OSA from a topological perspective.     

Prevalence of Sleep Apnea and Electrocardiographic Disturbances in Morbidly Obese Patients

Objective: To determine the prevalence of sleep apnea in morbidly obese patients and its relationship with cardiac arrhythmias. Research Methods and Procedures: Fifty‐two consecutive morbidly obese (body mass index ≥ 40 kg/m²) outpatients from the Obesity Clinic of the National Institute of Nutrition Salvador Zubirán underwent two nights of polysomnography with standard laboratory techniques. Electrocardiographic polysomnography signals (Lead II) were evaluated by two experienced cardiologists, and sleep complaints were measured with a standard sleep questionnaire (Sleep Disorders Questionnaire). In order to make comparisons between groups with different severities of sleep‐disordered breathing, we classified the patients in four groups using the apnea‐hypopnea index (AHI): Group 1, AHI 5 < 15 (n = 10); Group 2, AHI 15 < 30 (n = 10); Group 3, AHI 30 < 65 (n = 14); Group 4, AHI ≥ 65 (n = 17). Results: A wide range of sleep‐disordered breathing, ranging from AHI of 2.5 to 128.9 was found. Ninety‐eight percent of the sample (n = 51) had an AHI ≥ 5 (mean = 51 ± 37), and 33% had severe sleep apnea with AHI ≥ 65 with a mean nocturnal desaturation time of <65% over 135 minutes. Electrocardiographic abnormalities were present in 31% of the patients. Cardiac rhythm alterations showed an association with the level of sleep‐disordered breathing and oxygen desaturation. Discussion: We conclude that there is a high prevalence of sleep apnea in morbidly obese patients and that the risk for cardiac arrhythmias increases in this population in the presence of a severe sleep apnea (AHI ≥ 65) with severe oxygen desaturation (Sao ₂ ≤ 65%).     

阻塞性睡眠呼吸暂停综合征临床监测分析

目的:探讨阻塞性睡眠呼吸暂停综合征患者的临床特征及评价疗效。方法:回顾分析70例阻塞性睡眠呼吸暂停综合征患者PSG监测数据。结果:随着呼吸紊乱指数的增加,年龄、体重指数、最长呼吸暂停时间、最低SaO_2%、平均SaO_2%下降等指标在轻度与中、重度SAS之间差异显著;70例患者中伴有高血压52.9%、糖尿病5.7%、冠心病21.4%。结论:OSAS是一种具有潜在危险的疾痛,对OSAS早期诊断治疗是预防发生严重并发症的关键。     

The Effects of CPAP Treatment on Task Positive and Default Mode Networks in Obstructive Sleep Apnea Patients: An fMRI Study

Introduction

Functional magnetic resonance imaging studies enable the investigation of neural correlates underlying behavioral performance. We investigate the effect of active and sham Continuous Positive Airway Pressure (CPAP) treatment on working memory function of patients with Obstructive Sleep Apnea Syndrome (OSAS) considering Task Positive and Default Mode networks (TPN and DMN).

Methods

An experiment with 4 levels of visuospatial n-back task was used to investigate the pattern of cortical activation in 17 men with moderate or severe OSAS before and after 2 months of therapeutic (active) or sub-therapeutic (sham) CPAP treatment.

Results

Patients with untreated OSAS had significantly less deactivation in the temporal regions of the DMN as compared to healthy controls, but activation within TPN regions was comparatively relatively preserved. After 2 months of treatment, active and sham CPAP groups exhibited opposite trends of cerebral activation and deactivation. After treatment, the active CPAP group demonstrated an increase of cerebral activation in the TPN at all task levels and of task-related cerebral deactivation in the anterior midline and medial temporal regions of the DMN at the 3-back level, associated with a significant improvement of behavioral performance, whereas the sham CPAP group exhibited less deactivation in the temporal regions of Default Mode Network and less Task Positive Network activation associated to longer response times at the 3-back.

Conclusion

OSAS has a significant negative impact primarily on task-related DMN deactivation, particularly in the medial temporal regions, possibly due to nocturnal hypoxemia, as well as TPN activation, particularly in the right ventral fronto-parietal network. After 2 months of active nasal CPAP treatment a positive response was noted in both TPN and DMN but without compete recovery of existing behavioral and neuronal deficits. Initiation of CPAP treatment early in the course of the disease may prevent or slow down the occurrence of irreversible impairment.     

Obstructive Sleep Apnea Predisposes to Nonalcoholic Fatty Liver Disease in Patients with Polycystic Ovary Syndrome

ObjectiveSome studies have shown a higher prevalence of nonalcoholic fatty liver disease (NAFLD) and obstructive sleep apnea (OSA) in patients with polycystic ovary syndrome (PCOS). The objective of this study was to assess NAFLD in PCOS women with and without OSA. A possible role of high serum androgen levels in the development of OSA in PCOS women was also investigated.MethodsBiochemical, hormonal, and polysomnography parameters were determined in 38 premenopausal PCOS patients. NAFLD was evaluated by ultrasound. Testosterone was measured by an immunoassay.ResultsSerum androgen levels and the prevalence of NAFLD (83.3% vs. 26.9%; P < .001) were higher in patients with OSA than those without OSA. The mean apnea-hypopnea index (AHI) was higher in patients with NAFLD than in those without NAFLD (16.87 events [ev]/h vs. 1.57 ev/h; P < .002). On multivariate logistic regression, where body mass index ≥ 30 kg/m², homeostasis model assessment for insulin resistance ≥ 2.7, and OSA (AHI ≥ 5 ev/h) were independent variables, only OSA was an independent predictor of NAFLD (odds ratio [OR], 7.63; P = .044). Free testosterone levels ≥ 1.07 ng/dL were also independently associated with OSA (OR, 8.18; P = .023).ConclusionIn PCOS women, the occurrence of OSA strongly predisposes them to development of NAFLD and a worse metabolic profile; hence, treatment of OSA might be beneficial for NAFLD. (Endocr Pract. 2014;20:244-251)     

Relationship between Obstructive Sleep Apnea Severity and Sleep,Depression and Anxiety Symptoms in Newly-Diagnosed Patients

Obstructive sleep apnea (OSA) occurs in at least 10% of the population, and leads to higher morbidity and mortality; however, relationships between OSA severity and sleep or psychological symptoms are unclear. Existing studies include samples with wide-ranging comorbidities, so we assessed relationships between severity of OSA and common sleep and psychological disturbances in recently diagnosed OSA patients with minimal co-morbidities. We studied 49 newly diagnosed, untreated OSA patients without major co-morbidities such as mental illness, cardiovascular disease, or stroke; subjects were not using psychoactive medications or tobacco (mean ± std age: 46.8±9.1 years; apnea/hyponea index [AHI]: 32.1±20.5 events/hour; female/male: 12/37; weight <125 kg). We evaluated relationships between the AHI and daytime sleepiness (Epworth Sleepiness Scale; ESS), sleep quality (Pittsburg Sleep Quality Index; PSQI), depressive symptoms (Beck Depression Inventory-II; BDI), and anxiety symptoms (Beck Anxiety Inventory; BAI), as well as sex and body mass index (BMI). AHI was similar in females and males. Mean levels of all symptoms were above normal thresholds, but AHI was not correlated with age, ESS, PSQI, BDI, or BAI; only BMI was correlated with OSA severity. No differences in mean AHI appeared when subjects were grouped by normal versus elevated values of ESS, PSQI, BDI, or BAI. Consistent with other studies, a strong link between OSA severity and psychological symptoms did not appear in these newly diagnosed patients, suggesting that mechanisms additional to the number and frequency of hypoxic events and arousals occurring with apneas contribute to adverse health effects in OSA. OSA patients presenting with mild or moderate severity, and no major co-morbidities will not necessarily have low levels of sleep or psychological disturbances.     

A Novel Wearable Real-Time Sleep Apnea Detection System Based on the Acceleration Sensor

Background and objectiveThe apnea syndrome is characterized by an abnormal breath pause or reduction in the airflow during sleep. It is reported in the literature that, it affects 2% of middle-aged women and 4% of middle-aged men, approximately. This study has vital importance, especially for the elderly, the disabled, and pediatric sleep apnea patients.MethodsIn this study, a device is developed to detect apnea events to alert the patient. The device records continuously accelerations on the diaphragm by using an acceleration sensor, which is placed on the patient's diaphragm. When the apnea is detected by the accelerometer-based system, a signal is sent to the wristband, and then the vibration motor on the wristband vibrates until the patient starts breathing again. The force of the vibration motor can be adjusted according to the patients' sleep debt, especially for elderly, disabled, or pediatric patients. There is no need for a sleeping room to see the patients' breathing properties since those parameters can be stored by using the developed device on a secure digital memory card (SD) at patients' homes during sleeping.ResultsA study group were formed of 10 patients (4 males (40%) and 6 females (60%)) with different characteristics ([mean] age, 36.3; height, 169.6 cm; and body weight, 81.4 kg). The patients in the study group have sleep apnea (SA). All the apnea events were detected, and all the patients were successfully alerted. Also, the lying position, which is a significant issue, is performed in this study.ConclusionsThis work proposed using an acceleration sensor as a reliable method of sleep apnea screening, detection of an apnea event, sending alert to the patient, and detection of the patient lying position. The developed device is more economical, comfortable, and convenient than existing systems for not only the patients but also the doctors. The patients can easily use this device in their home environment.     

Impact of Acetazolamide and CPAP on Cortical Activity in Obstructive Sleep Apnea Patients

Study Objectives

1) To investigate the impact of acetazolamide, a drug commonly prescribed for altitude sickness, on cortical oscillations in patients with obstructive sleep apnea syndrome (OSAS). 2) To examine alterations in the sleep EEG after short-term discontinuation of continuous positive airway pressure (CPAP) therapy.

Design

Data from two double-blind, placebo-controlled randomized cross-over design studies were analyzed.

Setting

Polysomnographic recordings in sleep laboratory at 490 m and at moderate altitudes in the Swiss Alps: 1630 or 1860 m and 2590 m.

Patients

Study 1: 39 OSAS patients. Study 2: 41 OSAS patients.

Interventions

Study 1: OSAS patients withdrawn from treatment with CPAP. Study 2: OSAS patients treated with autoCPAP. Treatment with acetazolamide (500–750 mg) or placebo at moderate altitudes.

Measurements and Results

An evening dose of 500 mg acetazolamide reduced slow-wave activity (SWA; approximately 10%) and increased spindle activity (approximately 10%) during non-REM sleep. In addition, alpha activity during wake after lights out was increased. An evening dose of 250 mg did not affect these cortical oscillations. Discontinuation of CPAP therapy revealed a reduction in SWA (5–10%) and increase in beta activity (approximately 25%).

Conclusions

The higher evening dose of 500 mg acetazolamide showed the “spectral fingerprint” of Benzodiazepines, while 250 mg acetazolamide had no impact on cortical oscillations. However, both doses had beneficial effects on oxygen saturation and sleep quality.     

Distinct Associations between Hypertension and Obstructive Sleep Apnea in Male and Female Patients

Obstructive sleep apnea (OSA) is highly associated with hypertension. However, the correlation between hypertension and OSA at different levels of severity and the influence of gender on that correlation are unclear. A total of 996 patients (776 males and 190 females) with OSA were recruited. The influence of gender on the correlation between hypertension and OSA at different stratifications of severity, based on the apnea-hypopnea index (AHI), was fully evaluated together with the major health risk factors obesity, age, and diabetes. Females with OSA were significantly older on average than males with OSA. Moreover, females had milder degrees of OSA on average than the extent of severity seen in males. The proportion of females with diabetes or hypertension was higher than that of males. The proportion of males with hypertension and obesity increased significantly with OSA, and age also increased with OSA. The percentage of females with hypertension at different degrees of OSA severity was stable at about 26% in the mild, moderate, and severe OSA groups. Among females, age was increased significantly in the moderate relative to the mild OSA group. Moreover, the proportion of obese subjects was increased significantly in the severe compared with the moderate OSA group. The proportions of males and females with diabetes were not significantly different among all OSA severity groups. An ordinal multivariate logistic regression analysis confirmed that hypertension, age, and obesity were associated with OSA severity in males, whereas only age and obesity were associated with OSA severity in females. Although the proportion of subjects with hypertension was higher in females with OSA than in males with OSA, the proportion of subjects with hypertension increased as the severity of OSA increased in males but not in females.