NREM Parasomnias: Retrospective Analysis of Treatment Approaches and Comorbidities.

The aim of this retrospective analysis is to determine the most frequently prescribed medications for the treatment of NREM parasomnias and evaluate reported outcomes. We performed a retrospective chart review of all patients with NREM parasomnia diagnosed within Brigham and Women's Hospital (BWH) clinics examining the date of diagnosis, date of starting therapy, comorbidities, type of medication prescribed, and the reported change in symptoms or side effects at follow-up visits. From 2012 to 2019, 110 patients (59 females, 51 male) at BWH clinics received a diagnosis of NREM parasomnia, including sleepwalking and night terrors. The mean age was 44. Comorbidities included obstructive sleep apnea (OSA) (46%), periodic limb movement syndrome (PLMS) (13%), insomnia (19%), Restless leg syndrome (RLS) (9%), epilepsy (4%), and REM behavior disorder (RBD) (9%). Initial treatment strategies include behavioral and safety counseling only (34%), pharmacological treatment (29%), treatment of any comorbidity (28%), and combined treatment of any of the above (9%). Improvement was reported with: treatment of OSA (n = 23 52% reported improvement), melatonin (n = 8, improvement reported by 88%.,benzodiazepine (n = 7, improvement reported by 57%). Treating comorbid conditions is a frequent treatment strategy, often associated with symptom improvement. The pharmacologic treatment most commonly included melatonin and benzodiazepines. Comprehensive management should include behavioral and safety recommendations, assessment of comorbid conditions, and individually tailored pharmaceutical treatment.

Sleepiness in obstructive sleep apnea using hypopneas defined by a 3% oxygen desaturation or arousal but not by 4% or greater oxygen desaturation.

STUDY OBJECTIVES: This analysis determined the association between obstructive sleep apnea (OSA) with hypopneas defined by a 3% O2 desaturation or arousal (3%A), but not by a hypopnea criterion of ≥ 4% (4%), and subjective sleepiness. METHODS: Data were analyzed from Sleep Heart Health Study participants who had polysomnography (N = 6307) regarding OSA and subjective sleepiness scores (Epworth Sleepiness Scale, ESS). The apnea hypopnea index (AHI) was classified based on 3% only, 3%A only, and 4% definitions of hypopneas. RESULTS: Of the 3326 participants without 4% OSA, 67.6% (n = 2247) had 3%A only OSA. The ESS score was higher in 3%A only OSA than in those without OSA (7.44 ± 4.2 vs 7.07 ± 4.3, P = 0.02). Of those without 4% OSA, 40.2% (n = 1336) had 3% only OSA. The ESS score was higher in those with 3% only OSA than those with no OSA (7.72 ± 4.3 vs 7.05 ± 4.2, P < 0.001). A linear regression model demonstrated a trend towards significance for the 3%A only AHI as an independent predictor of ESS when controlled for age, BMI, and sex (P = 0.051). The association of 3% only AHI with the ESS was stronger (P = 0.003). However, 23.3% of the participants with hypersomnia would not qualify as having OSA if arousals were excluded from the definition of OSA. CONCLUSION: The current study found that the presence and severity of OSA is associated with higher ESS scores in persons with 3%A only OSA. Hence, the use of the 4% hypopnea definition will result in the failure to identify and treat a significant number of individuals with OSA who have subjective sleepiness.

Long-term All-Cause Mortality Risk in Obstructive Sleep Apnea Using Hypopneas Defined by a ≥3 Percent Oxygen Desaturation or Arousal.

STUDY OBJECTIVES: Some prior studies have demonstrated an increase in mortality associated with obstructive sleep apnea (OSA) utilizing a definition of OSA that requires a minimum 4% oxygen desaturation to identify a hypopnea. No large community-based studies have determined the risk of long-term mortality with OSA with hypopneas defined by a ≥3% O2 desaturation or arousal (AHI3%A). METHODS: Data from 5591 Sleep Heart Health Study participants without prevalent cardiovascular disease at baseline who underwent polysomnography were analyzed regarding OSA diagnosed using the AHI3%A criteria and all-cause mortality over a mean follow up period of 10.9±3.2 years. RESULTS: There were 1050 deaths in this group during the follow-up period. A Kaplan-Meir plot of survival revealed a reduction in survival with increasing AHI severity. Cox proportional hazards regression models revealed significantly increased all-cause mortality risk with increasing AHI, hazard ratio (HR, 95% CI) 1.13 (1.04-1.23), after adjusting for age, sex, race, BMI, cholesterol, HDL, self-reported hypertension and/or diabetes and smoking status. In categorical models, the mortality risk was significantly higher with severe OSA [adjusted HR 1.38 (1.09-1.76)]. When stratified by gender or age, severe OSA was associated with increased risk of death in men [adjusted HR 1.14 (1.01-1.28)] and in those <70 years of age [adjusted HR 1.51 (1.02-2.26)]. In contrast, AHI severity was not associated with increased mortality in women or those ≥70 years of age in fully adjusted models. CONCLUSION: Severe AHI3%A OSA is associated with significantly increased mortality risk, especially in men and those <70 years of age.

Titration studies overestimate continuous positive airway pressure requirements in uncomplicated obstructive sleep apnea.

STUDY OBJECTIVES: Attended manual continuous positive airway pressure (CPAP) titration is the standard practice for determining optimal positive airway pressures for obstructive sleep apnea (OSA) treatment. However, an unattended single night auto-titrating positive airway pressure (APAP) titration is an alternative. The goal of this study was to determine whether therapeutic CPAP pressures determined during manual titrations are higher than APAP-generated surrogate pressures. METHODS: We conducted a retrospective review of 165 adults with uncomplicated OSA who had full/split-night manual CPAP titrations prior to commencing treatment with APAP. Demographic and clinical data including 30-day APAP compliance data were obtained. We compared the recommended CPAP pressure from manual titrations with the 90th/95th percentile pressure generated from APAP usage over 30 days. RESULTS: The recommended CPAP pressures during the manual titrations were higher than the 90th/95th percentile pressures generated from APAP (11.4 ± 3.4 vs 10.3 ± 2.4 cmH2O; P = .000). Almost half the group (41.9%) had their manually derived titration pressure at least 1.5 cm above the 90th/95th percentile pressure. In multivariate analyses, body mass index was the only variable that predicted higher manual titration pressures. Notably, the average residual apnea-hypopnea index on 30-day APAP data was less than the average residual apnea-hypopnea index observed at the recommended pressure during the manual titration (5.0 ± 4.3 vs 7.2 ± 8.5; P = .006). CONCLUSIONS: Manual CPAP titrations may overestimate pressure requirements, particularly in patients with higher body mass index, and may not be necessary in managing patients with uncomplicated OSA. APAP appears to be at least as effective as single-pressure CPAP, while delivering lower positive airway pressure. CITATION: Fashanu OS, Budhiraja R, Batool-Anwar S, Quan SF. Titration studies overestimate continuous positive airway pressure requirements in uncomplicated obstructive sleep apnea. J Clin Sleep Med. 2021;17(9):1859-1863.

The Association Between Obstructive Sleep Apnea Defined by 3 Percent Oxygen Desaturation or Arousal Definition and Self-Reported Cardiovascular Disease in the Sleep Heart Health Study.

BACKGROUND: Studies have established that OSA defined using a hypopnea definition requiring a ≥4% oxygen desaturation (AHI4%) is associated with cardiovascular (CVD) or coronary heart (CHD) disease. This study determined whether OSA defined using a hypopnea definition characterized by a ≥3% oxygen desaturation or an arousal (AHI3%A) is associated with CVD/CHD. METHODS: Data were analyzed from 6307 Sleep Heart Health Study participants who had polysomnography. Self-reported CVD included angina, heart attack, heart failure, stroke, previous coronary bypass surgery or angioplasty. Self-reported CHD included the aforementioned conditions but not stroke or heart failure. The association between OSA and CVD/CHD was examined using logistic regression models with stepwise inclusion of demographic, anthropometric, social/behavioral and co-morbid medical conditions. A parsimonious model in which diabetes and hypertension were excluded because of their potential to be on the causal pathway between OSA and CVD/CHD also was constructed. RESULTS: For CVD, the odds ratios and 95% confidence intervals for AHI3%A ≥30/hour were 1.39 (1.03-1.87) and 1.45 (1.09-1.94) in the fully adjusted and parsimonious models. Results for CHD were 1.29 (0.96-1.74) and 1.36 (0.99-1.85). In participants without OSA according to more stringent AHI4% criteria but with OSA using the AHI3%A definition, similar findings were observed. CONCLUSION: OSA defined using an AHI3%A is associated with both CVD and CHD. Use of a more restrictive AHI4% definition will misidentify a large number of individuals with OSA who have CVD or CHD. These individuals may be denied access to therapy, potentially worsening their underlying CVD or CHD.

Incidence of hypertension in obstructive sleep apnea using hypopneas defined by 3 percent oxygen desaturation or arousal but not by only 4 percent oxygen desaturation.

STUDY OBJECTIVES: This analysis determined ∼5-year incident hypertension rates using the 2017 American College of Cardiology/American Heart Association blood pressure (BP) guidelines in individuals with obstructive sleep apnea (OSA) with hypopneas defined by a ≥ 3% oxygen desaturation or arousal but not by a hypopnea criterion of ≥ 4% oxygen desaturation (4% only). METHODS: Data were analyzed from participants in the Sleep Heart Health Study exam 2 (n = 1219) who were normotensive (BP ≤ 120/80 mm Hg) at exam 1. The AHI at exam 1 was classified into 4 categories of OSA severity: < 5, 5 ≤ 15, 15 ≤ 30, and ≥ 30 events/h using both the 3% oxygen desaturation or arousal and the 4% only definitions. Three definitions of hypertension-elevated BP (> 120/80 mm Hg), stage 1 (> 130/80 mm Hg), and stage 2 (> 140/90 mm Hg)-were used to determine incidence rates at exam 2. RESULTS: Five-year follow-up was available for 476 participants classified as having OSA by the 3% oxygen desaturation or arousal criterion but not by the 4% only standard at exam 1. Incident hypertension using American College of Cardiology/American Heart Association-defined BP categories in these discordantly classified individuals were 15% (elevated BP), 15% (stage 1), and 6% (stage 2). Hypertensive medications were used in 4% of participants who were normotensive. The overall incidence rate of at least an elevated BP was 40% (191/476) in those with OSA defined using the 3% oxygen desaturation or arousal criterion but not by the 4% only criterion. CONCLUSIONS: Use of the 4% only hypopnea definition resulted in the failure to identify a significant number of individuals with OSA who eventually developed hypertension and could have benefited from earlier diagnosis and treatment.

Prevalence and correlates of periodic limb movements in OSA and the effect of CPAP therapy.

OBJECTIVE: We sought to assess the prevalence, correlates, and consequences of periodic limb movements of sleep (PLMS) in persons with obstructive sleep apnea (OSA) and the effect (worsening or improvement) of continuous positive airway pressure (CPAP) therapy on PLMS in a large prospective multicenter randomized controlled trial. METHODS: We performed retrospective analyses of data from the Apnea Positive Pressure Long-term Efficacy Study, a prospective multicenter randomized controlled trial. A total of 1,105 persons with OSA enrolled in this study underwent a polysomnographic investigation at baseline, another one for CPAP titration, and another study 6 months after randomization to either active CPAP or sham CPAP. RESULTS: Of all participants, 19.7% had PLM index (PLMI) ≥10/hour, 14.8% had PLMI ≥15/hour, 12.1% had PLMI ≥20/hour, 9.3% had PLMI ≥25/hour, and 7.5% had PLMI ≥30/hour. The odds of having a PLMI ≥10 were higher in older participants (odds ratio [OR] 1.03, p < 0.001), men (OR 1.63. p = 0.007), those using antidepressants (OR 1.48. p = 0.048), and those with higher caffeine use (OR 1.01, p = 0.04). After controlling for OSA and depression, PLMS were associated with increased sleep latency, reduced sleep efficiency, and reduced total sleep time. No significant relationships were noted between PLMS frequency and subjective sleepiness (Epworth Sleepiness Scale score) or objective sleepiness (Maintenance of Wakefulness Test). There was no differential effect of CPAP in comparison to sham CPAP on PLMS after 6 months of therapy. CONCLUSIONS: PLMS are common in patients with OSA and are associated with a significant reduction in sleep quality over and above that conferred by OSA. Treatment with CPAP does not affect the severity of PLMS.

The Association Between Obstructive Sleep Apnea Characterized by a Minimum 3 Percent Oxygen Desaturation or Arousal Hypopnea Definition and Hypertension.

STUDY OBJECTIVES: The association between obstructive sleep apnea (OSA) and hypertension in prior studies has been determined using a definition of hypopnea requiring a 4% O2 desaturation. However, the American Academy of Sleep Medicine (AASM) recommends using a 3% O2 desaturation or an arousal. This analysis assesses the relationship between OSA and hypertension utilizing the AASM recommended definition and the 2018 American College of Cardiology/American Heart Association hypertension guidelines. METHODS: Data from 6113 participants from the Sleep Heart Health Study were analyzed. The AASM recommended apnea-hypopnea index (AHI) was classified into 4 categories of OSA severity: < 5, 5 to < 15, 15 to < 30 and ≥ 30 events/h. Three definitions of hypertension were used: elevated (> 120/< 80 or use of hypertension medications [meds]), stage 1/stage 2 (> 130/80 or meds), stage 2 (> 140/90 or meds). Data were analyzed using logistic regression controlling for demographics, smoking and body mass index. Multiple linear regression analysis assessed the relationship between natural log AHI, and systolic and diastolic blood pressure controlling for the same covariates. RESULTS: For all definitions of blood pressure elevation, increasing OSA severity was associated with greater likelihood of an elevated or hypertensive status in fully adjusted models (odds ratio [95% confidence interval]): elevated 1.30 (1.09-1.54), 1.39 (1.13-1.70) 1.69 (1.29-2.13); stage 1/2: 1.25 (1.06-1.47), 1.32 (1.10-1.59), 1.53 (1.23-1.91); stage 2: 1.07 (0.91-1.25), 1.21 (1.01-1.44), 1.37 (1.11-1.69) for AHI 5 to < 15, 15 to < 30 and > 30 events/h (< 5 events/h reference). Linear regression found that AHI was associated with both systolic and diastolic blood pressure in fully adjusted models. CONCLUSIONS: Use of the AASM recommended definition of hypopnea as a component of the AHI is associated with the presence of hypertension. CITATION: Budhiraja R, Javaheri S, Parthasarathy S, Berry RB, Quan SF. The association between obstructive sleep apnea characterized by a minimum 3 percent oxygen desaturation or arousal hypopnea definition and hypertension. J Clin Sleep Med. 2019;15(9):1261-1270.

Use of blood biomarkers to screen for obstructive sleep apnea.

PURPOSE: Obstructive sleep apnea (OSA) is a highly prevalent disorder associated with increased risk for cardiovascular disease, diabetes, and other chronic conditions. Unfortunately, up to 90% of individuals with OSA remain without a diagnosis or therapy. We assess the relationship between OSA and blood biomarkers, and test the hypothesis that combinations of markers provide a characteristic OSA signature with diagnostic screening value. This validation study was conducted in an independent cohort in order to replicate findings from a prior feasibility study. PATIENTS AND METHODS: This multicenter prospective study consecutively enrolled adult male subjects with clinically suspected OSA. All subjects underwent overnight sleep studies. An asymptomatic control group was also obtained. Five biomarkers were tested: glycated hemoglobin (HbA1c), C-reactive protein (CRP), uric acid, erythropoietin (EPO), and interleukin-6 (IL-6). RESULTS: The study enrolled 264 subjects. The combination of HbA1c+CRP+EPO (area under the curve 0.78) was superior to the Epworth Sleepiness Scale (ESS; 0.53) and STOP-Bang (0.70) questionnaires. In non-obese subjects, the combination of biomarkers (0.75) was superior to body mass index (BMI; 0.61). Sensitivity and specificity results, respectively, were: HbA1c+CRP+EPO (81% and 60%), ESS (78% and 19%), STOP-Bang (75% and 52%), BMI (81% and 56%), and BMI in non-obese patients (81% and 38%). CONCLUSION: We verify our hypothesis and replicate our prior feasibility findings that OSA is associated with a characteristic signature cluster of biomarker changes in men. Concurrent elevations of HbA1c, CRP, and EPO levels should generate a high suspicion of OSA and may have utility as an OSA screening tool. Biomarker combinations correlate with OSA severity and, therefore, may assist sleep centers in identifying and triaging higher risk patients for sleep study diagnosis and treatment.

Associations Between Sleep Quality, Sleep Architecture and Sleep Disordered Breathing and Memory After Continuous Positive Airway Pressure in Patients with Obstructive Sleep Apnea in the Apnea Positive Pressure Long-term Efficacy Study (APPLES).

OBJECTIVE: The role of sleep architecture in consolidation of memory has not been extensively investigated. In this study, the association of continuous positive airway pressure (CPAP) and sleep architecture and quality, and sleep disordered breathing on changes in memory are explored during the course of a 6 month clinical trial of CPAP or sham CPAP (APPLES). METHODS: 848 participants had polysomnographic and memory assessments (Buschke Selective Reminding Test [Buschke] and Digit Symbol Substitution Test [DSST]) at baseline, CPAP/Sham CPAP titration, and the 2 and 6 month time points. Half were assigned to the CPAP and Sham CPAP groups respectively. Changes in performance on the Buschke and the DSST were analyzed over the course of the study between CPAP and Sham CPAP as well as in relationship to changes in sleep architecture, sleep quality and sleep disordered breathing (SDB). RESULTS: Sleep architecture, sleep quality and SDB improved in the CPAP group at 6 months; performance on the Buschke and DSST improved equally in both CPAP and Sham CPAP groups. There also were no significant correlations between changes in the amount or percentage of sleep stages between baseline and the 6 months, and corresponding changes in either the Buschke or the DSST. However, when stratified by the upper quartile and lower 3 quartiles, greater changes in the Buschke occurred over 6 months in the top quartile of total sleep time (5.7±7.3 vs. 4.0±6.8, p≤0.01) and amount of N3 sleep (55.9±7.7 vs. 53.6±8.9 min, p≤0.01). Those with more %N3 at 6 months scored better on the Buschke as well (55.9±7.8 vs. 53.6±8.9, p≤0.01). Borderline improvement in the DSST over 6 months was observed in the top quartiles of amount of N3 and %N3. Those in the top quartile of the amount of REM and %REM also showed greater improvement in the Buschke after 6 months. No differences were observed for the AHI, but those in the top quartile of oxygen desaturation had worse scores on the Buschke at 6 months. CPAP/Sham CPAP adherence did not impact 6 month Buschke or DSST performance. CONCLUSIONS: CPAP improved long-term sleep duration, quality and architecture, but did not memory. However, large changes in REM and N3 sleep as well as moderate amounts of nocturnal hypoxemia are associated with changes in assessments of memory.

Predictors of sleepiness in obstructive sleep apnoea at baseline and after 6†months of continuous positive airway pressure therapy.

We evaluated factors associated with subjective and objective sleepiness at baseline and after 6 months of continuous positive airway pressure (CPAP) therapy in patients with obstructive sleep apnoea (OSA).We analysed data from the Apnoea Positive Pressure Long-term Efficacy Study (APPLES), a prospective 6-month multicentre randomised controlled trial with 1105 subjects with OSA, 558 of who were randomised to active CPAP. Epworth sleepiness scale (ESS) scores and the mean sleep latency (MSL) on the maintenance of wakefulness test at baseline and after 6 months of CPAP therapy were recorded.Excessive sleepiness (ESS score >10) was present in 543 (49.1%) participants. Younger age, presence of depression and higher apnoea-hypopnoea index were all associated with higher ESS scores and lower MSL. Randomisation to the CPAP group was associated with lower odds of sleepiness at 6 months. The prevalence of sleepiness was significantly lower in those using CPAP >4 h·night-1versus using CPAP ≤4 h·night-1 Among those with good CPAP adherence, those with ESS >10 at baseline had significantly higher odds (OR 8.2, p<0.001) of persistent subjective sleepiness.Lower average nightly CPAP use and presence of sleepiness at baseline were independently associated with excessive subjective and objective sleepiness after 6 months of CPAP therapy.

The Role of Big Data in the Management of Sleep-Disordered Breathing.

Analysis of large-volume data holds promise for improving the application of precision medicine to sleep, including improving identification of patient subgroups who may benefit from alternative therapies. Big data used within the health care system also promises to facilitate end-to-end screening, diagnosis, and management of sleep disorders; improve the recognition of differences in presentation and susceptibility to sleep apnea; and lead to improved management and outcomes. To meet the vision of personalized, precision therapeutics and diagnostics and improving the efficiency and quality of sleep medicine will require ongoing efforts, investments, and change in our current medical and research cultures.

An Official American Thoracic Society Research Statement: Impact of Mild Obstructive Sleep Apnea in Adults.

BACKGROUND: Mild obstructive sleep apnea (OSA) is a highly prevalent disorder in adults; however, whether mild OSA has significant neurocognitive and cardiovascular complications is uncertain. OBJECTIVES: The specific goals of this Research Statement are to appraise the evidence regarding whether long-term adverse neurocognitive and cardiovascular outcomes are attributable to mild OSA in adults, evaluate whether or not treatment of mild OSA is effective at preventing or reducing these adverse neurocognitive and cardiovascular outcomes, delineate the key research gaps, and provide direction for future research agendas. METHODS: Literature searches from multiple reference databases were performed using medical subject headings and text words for OSA in adults as well as by hand searches. Pragmatic systematic reviews of the relevant body of evidence were performed. RESULTS: Studies were incongruent in their definitions of "mild" OSA. Data were inconsistent regarding the relationship between mild OSA and daytime sleepiness. However, treatment of mild OSA may improve sleepiness in patients who are sleepy at baseline and improve quality of life. There is limited or inconsistent evidence pertaining to the impact of therapy of mild OSA on neurocognition, mood, vehicle accidents, cardiovascular events, stroke, and arrhythmias. CONCLUSIONS: There is evidence that treatment of mild OSA in individuals who demonstrate subjective sleepiness may be beneficial. Treatment may also improve quality of life. Future research agendas should focus on clarifying the effect of mild OSA and impact of effective treatment on other neurocognitive and cardiovascular endpoints as detailed in the document.

Impact of Randomization, Clinic Visits, and Medical and Psychiatric Cormorbidities on Continuous Positive Airway Pressure Adherence in Obstructive Sleep Apnea.

STUDY OBJECTIVES: To evaluate factors associated with continuous positive airway pressure (CPAP) adherence in patients with obstructive sleep apnea (OSA) in the Apnea Positive Pressure Long-term Efficacy Study (APPLES) cohort. METHODS: The data from a prospective 6-mo multicenter randomized controlled trial with 558 subjects randomized to active CPAP and 547 to sham CPAP were analyzed to assess adherence to CPAP during first 2 mo (early period) and during months 5-6 (late period). RESULTS: Participants randomized to active CPAP had higher hours of nightly adherence compared to the sham CPAP group at both 2 (4.9 ± 2.0 h versus 4.07 ± 2.14 h, p < 0.001) and 6 mo (4.70 ± 2.08 h versus 3.41 ± 2.19 h, p < 0.001). Those assigned to sham CPAP were more likely to correctly identify their treatment group (70.0% versus 55.2%, p < 0.001). Irrespective of treatment group assignment, those who believed they were receiving active CPAP had higher hours of adherence than those who thought they were in the sham CPAP group at both 2 mo (4.91 ± 2.01 versus 4.17 ± 2.17, p < 0.001) and 6 mo (4.65 ± 2.10 versus 3.65 ± 2.22, p < 0.001). Among those randomized to active CPAP, older age was significantly related to CPAP use > 4 h per night. Presence of cardiovascular disorders was associated with higher hours of CPAP use, whereas presence of anxiety was associated with a trend toward lower hours of CPAP use. Presence of nasal congestion was associated with a decrease in mean daily CPAP use between the early and the late adherence period. The adherence during the week prior to a clinic visit was higher than the average adherence during the 2-mo period prior to the visit. CONCLUSIONS: Randomization to active therapy, belief that one is in the active treatment group, older age, and possibly presence of cardiovascular disorders are positively linked to CPAP adherence. Nasal congestion and anxiety are negatively associated with CPAP adherence. CPAP nightly usage increases as clinic visits approach.

Sleep disorders in chronic obstructive pulmonary disease: etiology, impact, and management.

ABSTRACT: Chronic obstructive pulmonary disease (COPD) is a leading cause of morbidity and mortality and may frequently be complicated by sleep disorders. Insomnia and obstructive sleep apnea are commonly encountered in patients with COPD. Nocturnal hypoxemia is also prevalent in COPD may occur despite adequate awake oxygenation and can be especially severe in rapid eye movement sleep. Additionally, several factors--some of them unique to COPD--can contribute to sleep-related hypoventilation. Recognition of hypoventilation can be vital as supplemental oxygen therapy itself can acutely worsen hypoventilation and lead to disastrous consequences. Finally, accruing data establish an association between restless leg syndrome and COPD--an association that may be driven by hypoxemia and/or hypercapnia. Comorbid sleep disorders portend worse sleep quality, diminished quality of life, and multifarious other adverse consequences. The awareness and knowledge regarding sleep comorbidities in COPD has continued to evolve over past many years. There are still several lacunae, however, in our understanding of the etiologies, impact, and therapies of sleep disorders, specifically in patients with COPD. This review summarizes the latest concepts in prevalence, pathogenesis, diagnosis, and management of diverse sleep disorders in COPD.