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Study Objectives: Uncertainty exists over whether continuous positive airway pressure (CPAP) treatment improves moderate to vigorous physical activity levels in those with obstructive sleep apnea. We aimed to determine effects of CPAP on moderate to vigorous physical activity among participants with co-occurring cardiovascular disease and obstructive sleep apnea., Methods: The Sleep Apnea cardioVascular Endpoints (SAVE) trial recruited participants with confirmed cardiovascular disease history and obstructive sleep apnea, 45-75 years old. The 2,687 participants (1,346 randomized to CPAP plus usual care and 1,341 to usual care alone) were followed up for a mean of 3.7 years. Self-reported physical activity was recorded at baseline, 6, 24, and 48 months using the Godin-Shepard Leisure Time Exercise Questionnaire (LTEQ). We also determined effects on any limitation of physical activity reported on the physical functioning subscale of the 36-item short form questionnaire (SF-36) and proportions of participants reaching guideline recommended physical activity levels., Results: Among 2,601 participants with available data, those in the CPAP group reported significantly more physical activity compared to the usual care group, with approximately 20% higher reported moderate activities on the LTEQ during follow-up (adjusted mean 95% confidence interval) scores: 8.7, 7.5-9.9 vs 7.3, 6.1-8.5; P = .003). Those in the CPAP group also reported less limitation in physical activity (adjusted between-group difference in SF-36 physical functioning subscale score 1.66, 95% confidence interval 0.87-2.45; P < 0.001), and more reported sufficient levels of physical activity to meet recommendations., Conclusions: CPAP has positive effects on improving physical activity levels, consistent with long-term health benefits., Clinical Trial Registration: Registry: ClinicalTrials.gov; Name: Continuous Positive Airway Pressure Treatment of Obstructive Sleep Apnea to Prevent Cardiovascular Disease (SAVE); URL: https://clinicaltrials.gov/ct2/show/NCT00738179; Identifier: NCT00738179; and Registry: Australian New Zealand Clinical Trials Registry; Name: Sleep Apnea cardioVascular Endpoints study-An investigation of continuous positive airway pressure for the treatment of obstructive sleep apnea to prevent cardiovascular disease; URL: https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=83062&isReview=true; Identifier: ACTRN12608000409370., (© 2021 American Academy of Sleep Medicine.)

Background: The relation of snoring to risks of stroke and other major cardiovascular (CV) events is uncertain., Research Question: We aimed to determine associations of snoring patterns and major CV events in relation to OSA among participants of the international Sleep Apnea cardiovascular Endpoints (SAVE) trial., Study Design and Methods: Post hoc analyses of the SAVE trial, which involved 2,687 patients with coexisting moderate-to-severe OSA and established coronary or cerebral CV disease, who were randomly allocated to CPAP treatment plus usual care or usual care alone, and followed-up for a median 3.5 years. Associations of self-reported snoring patterns (frequency and loudness) and breathing pauses collected on the Berlin questionnaire at baseline and multiple times during follow-up, and adjudicated composites of CV outcomes (primary, CV death, nonfatal myocardial infarction, nonfatal stroke, and hospitalization for unstable angina, heart failure, or transient ischemic attack; and separately of cardiac and cerebral events), were evaluated in time-dependent Cox proportional hazards models adjusted for various confounders including the apnea-hypopnea index., Results: Increase (per category) of snoring frequency (adjusted hazard ratio [HR], 1.10; 95% CI, 1.02-1.20; P = .015), loudness (HR, 1.16; 95% CI, 1.06-1.27; P = .001), and breathing pauses (HR, 1.16; 95% CI, 1.08-1.25; P < .001) at any time point during follow-up were each associated with the primary composite CV outcome. These associations were driven by significant associations for cerebral rather than cardiac events, and positive interactions between the three snoring patterns for cerebral events. There was no significant interaction between CPAP treatment and snoring variables for cerebral events., Interpretation: Snoring in patients with OSA with established CV disease is associated with greater risks of cerebral but not cardiac events, independent of CPAP treatment and frequency of apnea and hypopnea events., Trial Registry: ClinicalTrials.gov; No.: NCT00738179; URL: www.clinicaltrials.gov., (Copyright © 2020 American College of Chest Physicians. Published by Elsevier Inc. All rights reserved.)

Importance: Many adults with obstructive sleep apnea (OSA) use device treatments inadequately and remain untreated., Objective: To determine whether combined palatal and tongue surgery to enlarge or stabilize the upper airway is an effective treatment for patients with OSA when conventional device treatment failed., Design, Setting, and Participants: Multicenter, parallel-group, open-label randomized clinical trial of upper airway surgery vs ongoing medical management. Adults with symptomatic moderate or severe OSA in whom conventional treatments had failed were enrolled between November 2014 and October 2017, with follow-up until August 2018., Interventions: Multilevel surgery (modified uvulopalatopharyngoplasty and minimally invasive tongue volume reduction; n = 51) or ongoing medical management (eg, advice on sleep positioning, weight loss; n = 51)., Main Outcomes and Measures: Primary outcome measures were the apnea-hypopnea index (AHI; ie, the number of apnea and hypopnea events/h; 15-30 indicates moderate and >30 indicates severe OSA) and the Epworth Sleepiness Scale (ESS; range, 0-24; >10 indicates pathological sleepiness). Baseline-adjusted differences between groups at 6 months were assessed. Minimal clinically important differences are 15 events per hour for AHI and 2 units for ESS., Results: Among 102 participants who were randomized (mean [SD] age, 44.6 [12.8] years; 18 [18%] women), 91 (89%) completed the trial. The mean AHI was 47.9 at baseline and 20.8 at 6 months for the surgery group and 45.3 at baseline and 34.5 at 6 months for the medical management group (mean baseline-adjusted between-group difference at 6 mo, -17.6 events/h [95% CI, -26.8 to -8.4]; P < .001). The mean ESS was 12.4 at baseline and 5.3 at 6 months in the surgery group and 11.1 at baseline and 10.5 at 6 months in the medical management group (mean baseline-adjusted between-group difference at 6 mo, -6.7 [95% CI, -8.2 to -5.2]; P < .001). Two participants (4%) in the surgery group had serious adverse events (1 had a myocardial infarction on postoperative day 5 and 1 was hospitalized for observation following hematemesis of old blood)., Conclusions and Relevance: In this preliminary study of adults with moderate or severe OSA in whom conventional therapy had failed, combined palatal and tongue surgery, compared with medical management, reduced the number of apnea and hypopnea events and patient-reported sleepiness at 6 months. Further research is needed to confirm these findings in additional populations and to understand clinical utility, long-term efficacy, and safety of multilevel upper airway surgery for treatment of patients with OSA., Trial Registration: Australian New Zealand Clinical Trials Registry: ACTRN12614000338662.

Objective: Despite evidence of a relationship among obstructive sleep apnea (OSA), metabolic dysregulation, and diabetes, it is uncertain whether OSA treatment can improve metabolic parameters. We sought to determine effects of long-term continuous positive airway pressure (CPAP) treatment on glycemic control and diabetes risk in patients with cardiovascular disease (CVD) and OSA., Research Design and Methods: Blood, medical history, and personal data were collected in a substudy of 888 participants in the Sleep Apnea cardioVascular Endpoints (SAVE) trial in which patients with OSA and stable CVD were randomized to receive CPAP plus usual care, or usual care alone. Serum glucose and glycated hemoglobin A 1c (HbA 1c ) were measured at baseline, 6 months, and 2 and 4 years and incident diabetes diagnoses recorded., Results: Median follow-up was 4.3 years. In those with preexisting diabetes ( n = 274), there was no significant difference between the CPAP and usual care groups in serum glucose, HbA 1c , or antidiabetic medications during follow-up. There were also no significant between-group differences in participants with prediabetes ( n = 452) or new diagnoses of diabetes. Interaction testing suggested that women with diabetes did poorly in the usual care group, while their counterparts on CPAP therapy remained stable., Conclusions: Among patients with established CVD and OSA, we found no evidence that CPAP therapy over several years affects glycemic control in those with diabetes or prediabetes or diabetes risk over standard-of-care treatment. The potential differential effect according to sex deserves further investigation., (© 2020 by the American Diabetes Association.)

Background: Despite the improvement in the prognosis of acute coronary syndrome (ACS), substantial morbidity and mortality remain. We aimed to evaluate the effect of obstructive sleep apnoea (OSA) and its treatment with continuous positive airway pressure (CPAP) on the clinical evolution of patients with ACS., Methods: We designed a multicentre, open-label, parallel-group, randomised controlled trial of patients with ACS at 15 hospitals in Spain. Eligible non-sleepy patients were men and women aged 18 years and older, admitted to hospital for documented symptoms of ACS. All patients underwent respiratory polygraphy during the first 24-72 h after admission. OSA patients were randomly assigned (1:1) to CPAP treatment plus usual care (CPAP group) or usual care alone (UC group) by a computerised system available 24 h a day. A group of patients with ACS but without OSA was also included as a reference group. Because of the nature of the intervention, the trial intervention could not be masked to either investigators or patients. Patients were monitored and followed for a minimum of 1 year. Patients were examined at the time of inclusion; after 1 month, 3 months, 6 months, 12 months, 18 months, 24 months, 30 months, and 36 months; and every 12 months thereafter, if applicable, during the follow-up period. The primary endpoint was the prevalence of a composite of cardiovascular events (cardiovascular death or non-fatal events [Acute myocardial infarction, non-fatal stroke, hospital admission for heart failure, and new hospitalisations for unstable angina or transient ischaemic attack]) in patients followed up for a minimum of 1 year. The primary analysis was done according to the intention-to-treat principle. This study is registered with Clinicaltrials.gov, NCT01335087 and is now closed., Findings: Between April 25, 2011, and Feb 2, 2018, a total of 2834 patients with ACS had respiratory polygraphy, of whom 2551 (90·01%) were recruited. 1264 (49·55%) patients had OSA and were randomly assigned to the CPAP group (n=633) or the UC group (n=631). 1287 (50·45%) patients did not have OSA, of whom 603 (46·85%) were randomly assigned to the reference group. Patients were followed up for a median of 3·35 years (IQR 1·50-5·31). The prevalence of cardiovascular events was similar in the CPAP and UC groups (98 events [16%] vs 108 events [17%]; hazard ratio [HR] 0·89 [95% CI 0·68-1·17]; p=0·40) during follow-up. Mean time of adherence to CPAP treatment was 2·78 h/night (SD 2·73). The prevalence of cardiovascular events was similar between patients in the reference group (90 [15%] events) and those in the UC group (102 (17%) events) during follow-up (1·01 [0·76-1·35]; p=0·93). The prevalence of cardiovascular events seem not to be related to CPAP compliance or OSA severity. 464 (74%) of 629 patients in the CPAP group had 1538 serious adverse events and 406 (65%) of 626 patients in the UC group had 1764 serious adverse events., Interpretation: Among non-sleepy patients with ACS, the presence of OSA was not associated with an increased prevalence of cardiovascular events and treatment with CPAP did not significantly reduce this prevalence., Funding: ResMed (Australia), Fondo de Investigación Sanitaria (Fondo Europeo de Desarrollo Regional), the Spanish Respiratory Society, the Catalonian Cardiology Society, Esteve-Teijin, Oxigen Salud, and ALLER., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Study Objectives: Insomnia and obstructive sleep apnea (OSA) commonly co-occur which makes OSA difficult to treat with continuous positive airway pressure (CPAP). We conducted a randomized controlled trial in participants with OSA and co-occurring insomnia to test the hypothesis that initial treatment with cognitive and behavioral therapy for insomnia (CBT-i), versus treatment as usual (TAU) would improve insomnia symptoms and increase subsequent acceptance and use of CPAP., Methods: One hundred and forty-five participants with OSA (apnea-hypopnea index ≥ 15) and comorbid insomnia were randomized to either four sessions of CBT-i, or TAU, before commencing CPAP therapy until 6 months post-randomization. Primary between-group outcomes included objective average CPAP adherence and changes in objective sleep efficiency by 6 months. Secondary between-group outcomes included rates of immediate CPAP acceptance/rejection, and changes in; sleep parameters, insomnia severity, and daytime impairments by 6 months., Results: Compared to TAU, participants in the CBT-i group had 61 min greater average nightly adherence to CPAP (95% confidence interval [CI] = 9 to 113; p = 0.023, d = 0.38) and higher initial CPAP treatment acceptance (99% vs. 89%; p = 0.034). The CBT-i group showed greater improvement of global insomnia severity, and dysfunctional sleep-related cognitions by 6 months (both: p < 0.001), and greater improvement in sleep impairment measures immediately following CBT-i. There were no between-group differences in sleep outcomes, or daytime impairments by 6 months., Conclusions: In OSA participants with comorbid insomnia, CBT-i prior to initiating CPAP treatment improves CPAP use and insomnia symptoms compared to commencing CPAP without CBT-i. OSA patients should be evaluated for co-occurring insomnia and considered for CBT-i before commencing CPAP therapy., Clinical Trial: Treating comorbid insomnia with obstructive sleep apnea (COMSIA) study: A new treatment strategy for patients with combined insomnia and sleep apnea, https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=365184 Australian New Zealand Clinical Trials Registry: ACTRN12613001178730. Universal Trial Number: U1111-1149-4230., (© Sleep Research Society 2019. Published by Oxford University Press on behalf of the Sleep Research Society. All rights reserved. For permissions, please e-mail journals.permissions@oup.com.)

Study Objectives: Poor adherence to continuous positive airway pressure (CPAP) commonly affects therapeutic response in obstructive sleep apnea (OSA). We aimed to determine predictors of adherence to CPAP among participants of the Sleep Apnea and cardioVascular Endpoints (SAVE) trial., Methods: SAVE was an international, randomized, open trial of CPAP plus usual care versus usual care (UC) alone in participants (45-75 years) with co-occurring moderate-to-severe OSA (≥12 episodes/h of ≥4% oxygen desaturation) and established cardiovascular (CV) disease. Baseline sociodemographic, health and lifestyle factors, OSA symptoms, and 1-month change in daytime sleepiness, as well as CPAP side effects and adherence (during sham screening, titration week, and in the first month), were entered in univariate linear regression analyses to identify predictors of CPAP adherence at 24 months. Variables with p <0.2 were assessed for inclusion in a multivariate linear mixed model with country, age, and sex included a priori and site as a random effect., Results: Significant univariate predictors of adherence at 24 months in 1,121 participants included: early adherence measures, improvement in daytime sleepiness at 1 month, fixed CPAP pressure, some measures of OSA severity, cardiovascular disease history, breathing pauses, and very loud snoring. While observed adherence varied between countries, adherence during sham screening, initial titration, and the first month of treatment retained independent predictive value in the multivariate model along with fixed CPAP pressure and very loud snoring., Conclusions: Early CPAP adherence had the greatest predictive value for identifying those at highest risk of non-adherence to long-term CPAP therapy., Clinical Trial Registration: SAVE is registered with clinicaltrials.gov (NCT00738179)., (© Sleep Research Society 2019. Published by Oxford University Press on behalf of the Sleep Research Society. All rights reserved. For permissions, please e-mail journals.permissions@oup.com.)

Study Objectives: Obstructive sleep apnea (OSA) is a serious and costly public health problem. The main medical treatment, continuous positive airway pressure, is efficacious when used, but poorly tolerated in up to 50% of patients. Upper airway reconstructive surgery is available when medical treatments fail but randomized trial evidence supporting its use is limited. This protocol details a randomized controlled trial designed to assess the clinical effectiveness, safety, and cost-effectiveness of a multilevel upper airway surgical procedure for OSA., Methods: A prospective, parallel-group, open label, randomized, controlled, multicenter clinical trial in adults with moderate or severe OSA who have failed or refused medical therapies. Six clinical sites in Australia randomly allocated participants in a 1:1 ratio to receive either an upper airway surgical procedure consisting of a modified uvulopalatopharyngoplasty and minimally invasive tongue volume reduction, or to continue with ongoing medical management, and followed them for 6 months., Results: Primary outcomes: difference between groups in baseline-adjusted 6 month OSA severity (apnea-hypopnea index) and subjective sleepiness (Epworth Sleepiness Scale). Secondary outcomes: other OSA symptoms (e.g. snoring and objective sleepiness), other polysomnography parameters (e.g. arousal index and 4% oxygen desaturation index), quality of life, 24 hr ambulatory blood pressure, adverse events, and adherence to ongoing medical therapies (medical group)., Conclusions: The Sleep Apnea Multilevel Surgery (SAMS) trial is of global public health importance for testing the effectiveness and safety of a multilevel surgical procedure for patients with OSA who have failed medical treatment., Clinical Trial Registration: Multilevel airway surgery in patients with moderate-severe Obstructive Sleep Apnea (OSA) who have failed medical management to assess change in OSA events and daytime sleepiness. https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=366019&isReview=true Australian New Zealand Clinical Trials Registry ACTRN12614000338662, prospectively registered on 31 March 2014., (© Sleep Research Society 2019. Published by Oxford University Press on behalf of the Sleep Research Society. All rights reserved. For permissions, please e-mail journals.permissions@oup.com.)

Background: Although recent evidence suggests that OSA treatment may cause weight gain, the long-term effects of CPAP on weight are not well established., Methods: This study was a post hoc analysis of the Sleep Apnea Cardiovascular Endpoints (SAVE) study, a multicenter, randomized trial of CPAP plus standard care vs standard care alone in adults with a history of cardiac or cerebrovascular events and moderate to severe OSA. Participants with weight, BMI, and neck and waist circumferences measured at baseline and during follow-up were included. Linear mixed models were used to examine sex-specific temporal differences, and a sensitivity analysis compared high CPAP adherers (≥ 4 h per night) with propensity-matched control participants., Results: A total of 2,483 adults (1,248 in the CPAP group and 1,235 in the control group) were included (mean 6.1 ± 1.5 measures of weight available). After a mean follow-up of 3.78 years, there was no difference in weight change between the CPAP and control groups, for male subjects (mean [95% CI] between-group difference, 0.07 kg [-0.40 to 0.54]; P = .773) or female subjects (mean [95% CI] between-group difference, -0.14 kg [-0.37 to 0.09]; P = .233). Similarly, there were no significant differences in BMI or other anthropometric measures. Although male participants who used CPAP ≥ 4 h per night gained slightly more weight than matched male control subjects without CPAP (mean difference, 0.38 kg [95% CI, 0.04 to 0.73]; P = .031), there were no between-group differences in other anthropometric variables, nor were there any differences between female high CPAP adherers and matched control subjects., Conclusions: Long-term CPAP use in patients with comorbid OSA and cardiovascular disease does not result in clinically significant weight change., Trial Registry: ClinicalTrials.gov; No.: NCT00738179; URL: www.clinicaltrials.gov., (Copyright © 2018 American College of Chest Physicians. Published by Elsevier Inc. All rights reserved.)

Reduced ventilatory control stability (elevated loop gain) is a key nonanatomical, pathological trait contributing to obstructive sleep apnea (OSA), yet the mechanisms responsible remain unclear. We sought to identify the key factors contributing to elevated loop gain in OSA (controller vs. plant contributions) and to examine whether abnormalities in these factors persist after OSA treatment. In 15 males (8 OSA, 7 height, weight- and age -matched controls), we measured loop gain, controller gain, and plant gain using a pseudorandom binary CO 2 stimulation method during wakefulness. Factors potentially influencing plant gain were also assessed (supine lung volume via helium dilution and spirometry). Measures were repeated 2 and 6 wk after initiating continuous positive airway pressure treatment. Loop gain (LG) was higher in OSA versus controls (LG at 1 cycle/min 0.28 ± 0.04 vs. 0.16 ± 0.04, P = 0.046, respectively), and the controller exhibited a greater peak response to CO 2 and faster roll-off in OSA. OSA patients also exhibited reduced forced expiratory volume in the first second and forced vital capacity compared with controls (92.2 ± 1.7 vs. 102.9 ± 3.5% predicted, P = 0.021; 93.4 ± 3.1 vs. 106.6 ± 3.6% predicted, P = 0.015, respectively). There was no effect of treatment on any variable. These findings confirm loop gain is higher in untreated OSA patients than in matched controls; however, this was not affected by treatment. NEW & NOTEWORTHY Elevated loop gain contributes to obstructive sleep apnea (OSA) pathophysiology. However, whether loop gain is inherently elevated in OSA or induced by OSA itself, whether it is elevated due to increased chemoreflex sensitivity or obesity-dependent reduced lung volume, and whether it is treatment reversible, are all currently uncertain. This study found loop gain was elevated in OSA versus age-, sex-, height-, and weight-matched controls. However, this was not altered by 6-wk continuous positive airway pressure treatment.

Importance: Obstructive sleep apnea (OSA) is the most common clinically significant breathing abnormality during sleep. It is highly prevalent among patients with atrial fibrillation (AF), and it promotes arrhythmogenesis and impairs treatment efficacy., Observations: The prevalence of OSA ranges from 3% to 49% in population-based studies and from 21% to 74% in patients with AF. Diagnosis and treatment of OSA in patients with AF requires a close interdisciplinary collaboration between electrophysiologists, cardiologists, and sleep specialists. Because the prevalence of OSA is high in patients with AF and most do not report daytime sleepiness, sleep-study evaluation may be reasonable for patients being considered for rhythm control strategy. Acute, transient apnea-associated atrial electrophysiological changes and increased occurrence of AF triggers associated with short episodes of intermittent deoxygenation and reoxygenation, intrathoracic pressure changes during obstructed breathing efforts, and sympathovagal activation combine to create a stimulus for AF triggers and a complex and dynamic substrate for AF during sleep. Repeated episodes of long-term OSA are eventually associated with structural remodeling and changes in electrical conduction in the atrium. Observational data suggest OSA reduces the efficacy of catheter-based and pharmacological antiarrhythmic therapy. Nonrandomized studies have shown that treatment of OSA by continuous positive airway pressure can help to maintain a sinus rhythm after electrical cardioversion and catheter ablation in patients with AF. However, it remains unclear which sleep apnea metric should be used to determine severity and guide such treatment in patients with AF., Conclusions and Relevance: Data from nonrandomized studies of patients with AF suggest that treatment of OSA by continuous positive airway pressure may help to maintain sinus rhythm after electrical cardioversion and improve catheter ablation success rates. Randomized clinical trials are needed to confirm the association between OSA and AF the benefits of treatment of OSA and the need for and cost-effectiveness of routine OSA screening and treatment.

Study Objectives: The degree of neurobehavioral impairment and treatment response in mild-moderate obstructive sleep apnea (OSA) compared to that of an appropriate control group are unclear. This study compared neurobehavioral function and response to continuous positive airway pressure (CPAP) treatment in patients with mild to moderate OSA with those of a non-sleep apneic community sample of similar demography., Methods: One hundred ten patients with OSA and 31 asymptomatic community dwellers underwent overnight polysomnography and neurobehavioral testing. Participants with OSA (n = 88) were treated with CPAP for 3 months, and repeat evaluations were performed at the end of the treatment period., Results: Compared to the community sample, participants with OSA were significantly sleepier, had impaired mood and quality of life, and showed decrements in neuropsychological function, specifically psychomotor function, working memory and vigilance. Some neuropsychological and mood outcomes were normalized with CPAP, but significant decrements persisted in most outcomes even in those participants with adequate device usage., Conclusions: Patients with mild to moderate OSA have significant neurobehavioral morbidity. During "gold standard" treatment, normal function was not achieved, even with adequate device usage. CPAP efficacy for improving sleepiness and neuropsychological function in this milder end of the OSA spectrum may be poor, which may affect CPAP adherence. These findings suggest that there may be neurological changes related to OSA that do not respond to CPAP treatment, the etiology of which requires further investigation., (© 2018 American Academy of Sleep Medicine)

Study Objectives: To determine if the type of continuous positive airway pressure (CPAP) mask interface influences CPAP treatment efficacy, adherence, side effects, comfort and sleep quality in patients with moderate-severe obstructive sleep apnea (OSA)., Methods: This took place in a hospital-based tertiary sleep disorders unit. It is a prospective, randomized, crossover trial comparing three CPAP interfaces: nasal mask (NM), nasal mask plus chinstrap (NM-CS) and oronasal mask (ONM) each tried in random order, for 4 weeks. After each 4-week period, patient outcomes were assessed. Participants had a new diagnosis of obstructive sleep apneas. Forty-eight patients with moderate-severe OSA (32 males, mean ± standard deviation apnea-hypopnea index (AHI) 55.6 ± 21.1 events/h, age 54.9 ± 13.1 years, body mass index 35.8 ± 7.2 kg/m 2 ) were randomized. Thirty-five participants completed the full study, with complete data available for 34 patients., Results: There was no statistically significant difference in CPAP adherence; however, residual AHI was higher with ONM than NM and NM-CS (residual AHI 7.1 ± 7.7, 4.0 ± 3.1, 4.2 ± 3.7 events/h respectively, main effect P = .001). Patient satisfaction and quality of sleep were higher with the NM and NM-CS than the ONM. Fewer leak and mask fit problems were reported with NM (all chi-square P < .05), which patients preferred over the NM-CS and ONM options (n = 22, 9 and 4 respectively, P = .001)., Conclusions: The CPAP adherence did not differ between the three different mask interfaces but the residual AHI was lower with NM than ONM and patients reported greater mask comfort, better sleep, and overall preference for a NM. A nasal mask with or without chinstrap should be the first choice for patients with OSA referred for CPAP treatment., Clinical Trial Registration: Registry: Australian and New Zealand Clinical Trials Registry, URL: https://www.anzctr.org.au, title: A comparison of continuous positive airway pressure (CPAP) interface in the control of leak, patient compliance and patient preference: nasal CPAP mask and chinstrap versus full face mask in patients with obstructive sleep apnoea (OSA), identifier: ACTRN12609000029291., (© 2018 American Academy of Sleep Medicine)

Rationale: Obstructive sleep apnea (OSA) is associated with impaired renal function, but uncertainty exists over whether OSA treatment can influence renal outcomes., Objectives: To determine the effects of continuous positive airway pressure (CPAP) on renal function in subjects with coexisting OSA and cardiovascular disease., Methods: This was a substudy of the international SAVE (Sleep Apnea Cardiovascular Endpoints) trial, in which 2,717 patients with moderate to severe OSA and established coronary or cerebrovascular disease were randomized to receive either CPAP plus usual care or usual care alone. Renal function and adverse renal events were compared between the CPAP (n = 102) and usual care (n = 98) groups. Glomerular filtration rate was estimated at randomization and at the end of follow-up, and the urinary albumin-to-creatinine ratio was measured at study exit., Measurements and Main Results: In 200 substudy participants (mean age, 64 yr; median, 4% oxygen desaturation index; 20 events/h; mean estimated glomerular filtration rate at baseline, 82 ml/min/1.73 m 2 ), the median (interquartile range) changes in estimated glomerular filtration rate (ml/min/1.73 m 2 /yr) were -1.64 (-3.45 to -0.740) in the CPAP group and -2.30 (-4.53 to -0.71) in the usual care group (P = 0.21) after a median of 4.4 years. There were no between-group differences in end-of-study urinary albumin-to-creatinine ratio or in the occurrence of serious renal or urinary adverse events during the trial. The level of CPAP adherence did not influence the findings., Conclusions: CPAP treatment of OSA in patients with cardiovascular disease does not alter renal function or the occurrence of renal adverse events. Clinical trial registered with www.clinicaltrials.gov (NCT00738179).

Study Objectives: The choice of mask interface used with continuous positive airway pressure (CPAP) therapy can affect the control of upper airway obstruction (UAO) in obstructive sleep apnea (OSA). We describe a case series of four patients with paradoxical worsening of UAO with an oronasal mask and the effect of changing to a nasal mask., Methods: We retrospectively reviewed the case histories of 4 patients and recorded patient demographics, in-laboratory and ambulatory CPAP titration data, CPAP therapy data, type of mask interface used and potential confounding factors., Results: The 4 cases (mean ± SD: age = 59 ± 16 y; BMI = 30.5 ± 4.5 kg/m(2)) had a high residual apnoea-hypopnea index (AHI) (43 ± 14.2 events/h) and high CPAP pressure requirements (14.9 ± 6.6 cmH2O) with an oronasal mask. Changing to a nasal mask allowed adequate control of UAO with a significant reduction in the average residual AHI (3.1 ± 1.5 events/h). In two of the four cases, it was demonstrated that control of UAO was obtained at a much lower CPAP pressure compared to the oronasal mask (Case one = 17.5 cmH2O vs 12cmH2O; Case two = 17.9 cmH2O vs 7.8 cmH2O). Other potential confounding factors were unchanged. There are various physiological observations that may explain these findings but it is uncertain which individuals are susceptible to these mechanisms., Conclusions: If patients have OSA incompletely controlled by CPAP with evidence of residual UAO and/or are requiring surprisingly high CPAP pressure to control OSA with an oronasal mask, the choice of mask should be reviewed and consideration be given to a trial of a nasal mask., Commentary: A commentary on this article appears in this issue on page 1209., (© 2016 American Academy of Sleep Medicine.)

Background: Obstructive sleep apnea is associated with an increased risk of cardiovascular events; whether treatment with continuous positive airway pressure (CPAP) prevents major cardiovascular events is uncertain., Methods: After a 1-week run-in period during which the participants used sham CPAP, we randomly assigned 2717 eligible adults between 45 and 75 years of age who had moderate-to-severe obstructive sleep apnea and coronary or cerebrovascular disease to receive CPAP treatment plus usual care (CPAP group) or usual care alone (usual-care group). The primary composite end point was death from cardiovascular causes, myocardial infarction, stroke, or hospitalization for unstable angina, heart failure, or transient ischemic attack. Secondary end points included other cardiovascular outcomes, health-related quality of life, snoring symptoms, daytime sleepiness, and mood., Results: Most of the participants were men who had moderate-to-severe obstructive sleep apnea and minimal sleepiness. In the CPAP group, the mean duration of adherence to CPAP therapy was 3.3 hours per night, and the mean apnea-hypopnea index (the number of apnea or hypopnea events per hour of recording) decreased from 29.0 events per hour at baseline to 3.7 events per hour during follow-up. After a mean follow-up of 3.7 years, a primary end-point event had occurred in 229 participants in the CPAP group (17.0%) and in 207 participants in the usual-care group (15.4%) (hazard ratio with CPAP, 1.10; 95% confidence interval, 0.91 to 1.32; P=0.34). No significant effect on any individual or other composite cardiovascular end point was observed. CPAP significantly reduced snoring and daytime sleepiness and improved health-related quality of life and mood., Conclusions: Therapy with CPAP plus usual care, as compared with usual care alone, did not prevent cardiovascular events in patients with moderate-to-severe obstructive sleep apnea and established cardiovascular disease. (Funded by the National Health and Medical Research Council of Australia and others; SAVE ClinicalTrials.gov number, NCT00738179 ; Australian New Zealand Clinical Trials Registry number, ACTRN12608000409370 .).

Rationale: Obstructive sleep apnea (OSA) is associated with increased risk of cardiovascular disease. Continuous positive airway pressure (CPAP) delivered via a nasal mask during sleep immediately alleviates obstructive apneas and improves sleep quality and daytime somnolence. However, there is uncertainty as to whether such treatment can modify CV risk and disease., Aims: The Sleep Apnea Cardiovascular Endpoints (SAVE) study aims to determine whether CPAP on top of best medical care compared to best medical care alone can reduce the risk of serious CV events in patients with co-morbid OSA and established CV disease., Design: SAVE is an investigator initiated and conducted, international, multicenter, open, blinded endpoint, randomized controlled trial. Participants were randomised to either CPAP or usual care between 2008 and 2013 and will be followed up for an average of approximately 4 years., Study Outcome: The primary endpoint is a composite of CV death, myocardial infarction (MI, including silent MI), stroke, hospitalisation for heart failure, hospitalisation for an acute ischemic cardiac event (unstable angina) or cerebral event (transient ischemic event [TIA])., Discussion: The pre-specified statistical analysis plan (SAP) for the main analyses is presented. This SAP was finalised before patient follow-up was completed and before any unblinding of the data. The SAP outlines details of the primary, secondary and tertiary outcomes, together with planned subgroup and exploratory analyses., (© 2016 World Stroke Organization.)

Abstract: The Sleep Apnea cardioVascular Endpoints (SAVE) study is an ongoing investigator-initiated and conducted, international, multicenter, open, blinded endpoint, randomized controlled trial that was designed to determine whether treatment of obstructive sleep apnea (OSA) with continuous positive airways pressure (CPAP) can reduce the risk of serious cardiovascular (CV) events in patients with established CV disease (clinical trial registration NCT00738179). The results of this study will have important implications for the provision of health care to patients with sleep apnea around the world. The SAVE study has brought together respiratory, sleep, CV and stroke clinicians-scientists in an interdisciplinary collaboration with industry and government sponsorship to conduct an ambitious clinical trial. Following its launch in Australia and China in late 2008, the recruitment network expanded across 89 sites that included New Zealand, India, Spain, USA, and Brazil for a total of 2,717 patients randomized by December 2013. These patients are being followed until December 2015 so that the average length of follow-up of the cohort will be over 4 y. This article describes the rationale for the SAVE study, considerations given to the design including how various cultural and ethical challenges were addressed, and progress in establishing and maintaining the recruitment network, patient follow-up, and adherence to CPAP and procedures. The assumptions underlying the original trial sample size calculation and why this was revised downward in 2012 are also discussed., Clinical Trials Registration Number: NCT00738179., Australia New Zealand Clinical Trials Registry Number: ACTRN12608000409370., (© 2015 Associated Professional Sleep Societies, LLC.)

Study Objectives: To determine the clinical variables that best predict long- term continuous positive airway pressure (CPAP) adherence among patients with cardiovascular disease who have obstructive sleep apnea (OSA)., Design: 12-mo prospective within-trial observational study., Setting: Centers in China, Australia, and New Zealand participating in the Sleep Apnea cardioVascular Endpoints (SAVE) study., Patients: There were 275 patients age 45-70 y with cardiovascular disease (i.e., previously documented transient ischemic attack, stroke, or coronary artery disease) and OSA (4% oxygen desaturation index (ODI) > 12) who were randomized into the CPAP arm of the SAVE trial prior to July 1, 2010., Methods: Age, sex, country of residence, type of cardiovascular disease, baseline ODI, severity of sleepiness, and Hospital Anxiety and Depression Scale (HADS) scores plus CPAP side effects and adherence at 1 mo were entered in univariate analyses in an attempt to identify factors predictive of CPAP adherence at 12 mo. Variables with P < 0.2 were then included in a multivariate analysis using a linear mixed model with sites as a random effect and 12-mo CPAP use as the dependent outcome variable., Measurements and Results: CPAP adherence at 1, 6, and 12 mo was (mean ± standard deviation) 4.4 ± 2.0, 3.8 ± 2.3, and 3.3 ± 2.4 h/night, respectively. CPAP use at 1 mo (effect estimate ± standard error, 0.65 ± 0.07 per h increase, P < 0.001) and side effects at 1 mo (-0.24 ± 0.092 per additional side effect, P = 0.009) were the only independent predictors of 12- mo CPAP adherence., Conclusion: Continuous positive airway pressure use in patients with coexisting cardiovascular disease and moderate to severe obstructive sleep apnea decreases significantly over 12 months. This decline can be predicted by early patient experiences with continuous positive airway pressure (i.e., adherence and side effects at 1 month), raising the possibility that intensive early interventions could improve long-term continuous positive airway pressure compliance in this patient population., Clinical Trials Register: Clinical Trials, http://www.clinicaltrials.gov, NCT00738179.

Importance: Due to increasing demand for sleep services, there has been growing interest in ambulatory models of care for patients with obstructive sleep apnea. With appropriate training and simplified management tools, primary care physicians are ideally positioned to take on a greater role in diagnosis and treatment., Objective: To compare the clinical efficacy and within-trial costs of a simplified model of diagnosis and care in primary care relative to that in specialist sleep centers., Design, Setting, and Patients: A randomized, controlled, noninferiority study involving 155 patients with obstructive sleep apnea that was treated at primary care practices (n=81) in metropolitan Adelaide, 3 rural regions of South Australia or at a university hospital sleep medicine center in Adelaide, Australia (n = 74), between September 2008 and June 2010., Interventions: Primary care management of obstructive sleep apnea vs usual care in a specialist sleep center; both plans included continuous positive airway pressure, mandibular advancement splints, or conservative measures only., Main Outcome and Measures: The primary outcome was 6-month change in Epworth Sleepiness Scale (ESS) score, which ranges from 0 (no daytime sleepiness) to 24 points (high level of daytime sleepiness). The noninferiority margin was -2.0. Secondary outcomes included disease-specific and general quality of life measures, obstructive sleep apnea symptoms, adherence to using continuous positive airway pressure, patient satisfaction, and health care costs., Results: There were significant improvements in ESS scores from baseline to 6 months in both groups. In the primary care group, the mean baseline score of 12.8 decreased to 7.0 at 6 months (P < .001), and in the specialist group, the score decreased from a mean of 12.5 to 7.0 (P < .001). Primary care management was noninferior to specialist management with a mean change in ESS score of 5.8 vs 5.4 (adjusted difference, -0.13; lower bound of 1-sided 95% CI, -1.5; P = .43). There were no differences in secondary outcome measures between groups. Seventeen patients (21%) withdrew from the study in the primary care group vs 6 patients (8%) in the specialist group., Conclusions and Relevance: Among patients with obstructive sleep apnea, treatment under a primary care model compared with a specialist model did not result in worse sleepiness scores, suggesting that the 2 treatment modes may be comparable. TRIAL REGISTRATION anzctr.org.au Identifier: ACTRN12608000514303.

Objective: To assess the effects of 3 months of optimal CPAP treatment on auditory event related potentials (AERP) in patients with severe obstructive sleep apnoea (OSA) compared with healthy controls., Methods: Auditory odd-ball related N1, P2, N2 and P3 AERP components were assessed in 9 severe OSA subjects and 9 healthy controls at baseline evaluation and at ∼3 months follow-up in both groups, with OSA subjects treated with continuous positive air-way pressure (CPAP) during this period., Results: Severe OSA subjects showed significantly delayed, P2, N2 and P3 latencies, and significantly different P2 and P3 amplitudes compared to controls at baseline (group effect, all p<0.05). At follow-up evaluation P3 latency shortened in treated OSA patients but remained prolonged compared to controls (group by treatment interaction, p<0.05) despite high CPAP compliance (6h/night). The earlier AERP (P2 and N2) components did not change in either controls or OSA patients at follow-up and remained different in patients versus controls., Conclusions: This study demonstrates that in severe OSA patients AERP responses show minimal or no improvement and remain abnormal following 3 months of optimal CPAP treatment., Significance: Persistent cortical sensory processing abnormalities despite treatment in severe OSA may have implications for daytime neurobehavioral performance and safety in OSA patients. AERP responses may help identify residual performance deficits and risks., (Copyright © 2011 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.)

This study, in optimally treated CAD patients with newly diagnosed OSA, focused on (1) The relationships between OSA and serum biomarkers of four potential pathways of cardiovascular injury in OSA: high-sensitivity C-reactive protein (hs-CRP), endothelin-1 (ET-1), N terminal pro B type natriuretic peptide (NT-proBNP) and fibrinogen; and (2) The effect of continuous positive airway pressure (CPAP) therapy on these markers. 151 Chinese patients with proven CAD and standard medication were enrolled. After polysomnography, patients were classified into four groups according to apnea-hypopnea index (AHI): no OSA (n = 25); mild OSA (n = 50); moderate OSA (n = 43); severe OSA (n = 33). Morning levels of hs-CRP, ET-1, NT-proBNP and fibrinogen were assayed and repeated in severe OSA patients after 3-months CPAP treatment. Hs-CRP was greater in patients with severe OSA than those with no OSA or mild OSA (P = 0.001, P = 0.003; respectively). After adjustment for confounders, the hs-CRP levels correlated most strongly with AHI and oxygen desturation index (ODI) (r = 0.439, P < 0.001; r = 0.445, P < 0.001; respectively). In stepwise multiple linear regressions, the strongest predictor of hs-CRP levels was ODI (P < 0.001). After 3 months of CPAP treatment, the hs-CRP levels deceased (P = 0.005) in CAD patients with severe OSA. In CAD patients on current optimal medications, hs-CRP is significantly correlated with the severity of OSA, and the elevated hs-CRP levels can be decreased by CPAP. This suggests that OSA could activate vascular inflammation in CAD patients despite current best practice medications., (Copyright © 2011 Elsevier Ltd. All rights reserved.)

Study Objectives: To assess the effectiveness of CPAP treatment in improving 90-minute driving simulator performance in severe OSA patients compared to age/gender matched controls., Design: Driving simulator performance was assessed at baseline and 3 months later, with OSA patients treated with CPAP during the interval., Setting: University Teaching Hospital., Participants: Patients with severe OSA (n = 11) and control subjects without OSA (n = 9)., Interventions: CPAP MEASUREMENTS AND RESULTS: Simulator driving parameters of steering deviation, braking reaction time and crashes were measured at baseline and ∼3 months follow-up. At baseline, OSA subjects demonstrated significantly greater steering deviation compared to controls (mean [95% CI], OSA group, 49.9 cm [43.7 to 56.0 cm] vs control group, 34.9 cm [28.1 to 41.7 cm], p = 0.003). Following ∼3 months of CPAP treatment (mean ± SD 6.0 ± 1.4 h/night), steering deviation in OSA subjects improved by an average of 3.1 cm (CI, 1.4 to 4.9), p < 0.001, while no significant steering changes were observed in the control group. Despite the improvement, steering deviation in the OSA group remained significantly higher than in controls (OSA group, 46.7 cm [CI, 40.6 to 52.8 cm] vs control group, 36.1 cm [CI, 29.3 to 42.9 cm], p = 0.025)., Conclusions: While driving simulator performance improved after ∼3 months of CPAP treatment with high adherence in patients with severe OSA, performance remained impaired compared to control subjects. These results add to the growing body of evidence that some neurobehavioral deficits in patients with severe OSA are not fully reversed by treatment. Further studies are needed to assess causes of residual driving simulator impairment and to determine whether this is associated with persistent elevated real-life accident risk., Trial Registration: Data presented in this manuscript was collected as part of a clinical trial "Experimental Investigations of Driving Impairment in Obstructive Sleep Apnoea" ACTRN12610000009011, http://www.anzctr.org.au/trial&#95;view.aspx?ID=334979

Study Objectives: The study aimed to document the neurobehavioral outcomes of patients referred to and treated by a sleep medicine service for moderate to severe obstructive sleep apnea (OSA). In particular, we aimed to establish the proportion of patients who, while appearing to have optimal continuous positive airway pressure (CPAP) adherence, did not normalize their daytime sleepiness or neurocognitive function after 3 months of CPAP therapy despite effective control of OSA., Design: Multicenter clinical-effectiveness study., Setting: Three academic sleep centers in Australia., Participants: Patients referred to a sleep medicine service with moderate to severe OSA (n = 174)., Intervention: CPAP., Measurements and Results: Participants were assessed pretreatment and again after 3 months of CPAP therapy. At the beginning and at the conclusion of the trial, participants completed a day of testing that included measures of objective and subjective daytime sleepiness, neurocognitive function, and quality of life. In patients with symptomatic moderate to severe OSA (i.e., apnea-hypopnea index > 30/h), we found a treatment dose-response effect for CPAP in terms of Epworth Sleepiness Scale scores (P < 0.001). Several key indexes of neurobehavior (e.g., Functional Outcomes of Sleep Questionnaire, Epworth Sleepiness Scale) currently used to assess treatment response failed to normalize in a substantial group of patients after 3 months of CPAP treatment, even in those who were maximally compliant with treatment. Forty percent of patients in this trial had an abnormal Epworth Sleepiness Scale score at the conclusion of the trial. In addition, we showed no dose-response effect with the Maintenance of Wakefulness Test, raising doubts as to the clinical utility of the Maintenance of Wakefulness Test in assessing treatment response to CPAP in patients with OSA., Conclusions: Our study suggests that a greater percentage of patients achieve normal functioning with longer nightly CPAP duration of use, but a substantial proportion of patients will not normalize neurobehavioral responses despite seemingly adequate CPAP use. It is thus crucial to adequately assess patients after CPAP therapy and seek alternate etiologies and treatments for any residual abnormalities.

Introduction: Central sleep apnea (CSA) may occur in patients with snoring and obstructive sleep apnea-hypopnea (OSAH) during commencement of continuous positive airway pressure (CPAP) therapy. The presence of CSA may limit the effectiveness of CPAP therapy. The aims of this study were to assess the prevalence of CSA amongst patients starting CPAP for OSAH and to identify possible predictors of this condition., Methods: We reviewed the polysomnograms (PSGs) and clinical records of 99 consecutive patients with a primary diagnosis of OSAH who were referred for an in-laboratory CPAP titration study. Patients with a CSA Index of > or =5 per hour at or near (+/-1 cm H2O) prescribed CPAP level formed the CSA-CPAP group. The remaining patients made up the noCSA-CPAP group. Demographic, baseline and CPAP titration PSG variables were compared between the 2 two groups., Results: 13 subjects (13.1%) had CSA-CPAP. Patients with and without CSA-CPAP did not differ with respect to age or body mass index. 46% of patients with CSA-CPAP had CSA on their baseline PSGs compared with 8% in the noCSA-CPAP group (p <0.01). CSA-CPAP patients also had a higher apnea-hypopnea index (72.1 vs. 52.7 p = 0.02), a higher arousal index (43.3 vs. 29.2 p <0.01), and a higher mixed apnea index (6.8 vs. 1.3 p = 0.03), on their baseline PSGs. Therapeutic CPAP could not be determined in 2 CSA-CPAP patients due to a very high frequency (of severe) central apneas. In the remaining 11, the CPAP prescription to eliminate obstructive events was higher than in the noCSA-CPAP group (11.0 vs. 9.3 p = 0.08). AHI was greater both at or near prescribed CPAP (48.8 vs. 6.7 p <0.01) and overall (47.4 vs. 14.9 p <0.01). A history of ischemic heart disease or heart failure was more frequent amongst patients with CSA-CPAP than those without (p = 0.03)., Conclusion: A significant minority of patients with a primary diagnosis of OSAH have either emergence or persistence of CSA on CPAP. Risk factors include male sex, history of cardiac disease, and CSA on baseline PSG.

Continuous positive airway pressure (CPAP) is the first-line treatment for obstructive sleep apnea (OSA). Although CPAP improves symptoms (e.g., daytime sleepiness), there is a lack of high-quality evidence that CPAP prevents many long-term outcomes, including cognitive impairment, myocardial infarction, and stroke. Observational studies suggest that patients with symptoms may be particularly likely to experience these preventive benefits with CPAP, but ethical and practical concerns limited the participation of such patients in prior long-term randomized trials. As a result, there is uncertainty about the full benefits of CPAP, and resolving this uncertainty is a key priority for the field. This workshop assembled clinicians, researchers, ethicists, and patients to identify strategies to understand the causal effects of CPAP on long-term clinically important outcomes among patients with symptomatic OSA. Quasi-experimental designs can provide valuable information and are less time and resource intensive than trials. Under specific conditions and assumptions, quasi-experimental studies may be able to provide causal estimates of CPAP's effectiveness from generalizable observational cohorts. However, randomized trials represent the most reliable approach to understanding the causal effects of CPAP among patients with symptoms. Randomized trials of CPAP can ethically include patients with symptomatic OSA, as long as there is outcome-specific equipoise, adequate informed consent, and a plan to maximize safety while minimizing harm (e.g., monitoring for pathologic sleepiness). Furthermore, multiple strategies exist to ensure the generalizability and practicality of future randomized trials of CPAP. These strategies include reducing the burden of trial procedures, improving patient-centeredness, and engaging historically excluded and underserved populations. [ABSTRACT FROM AUTHOR]

Rationale: Primary care clinicians may be well placed to play a greater role in obstructive sleep apnea (OSA) management. Objectives: To evaluate the outcomes and cost-effectiveness of sleep apnea management in primary versus specialist care, using an individual-participant data meta-analysis to determine whether age, sex, severity of OSA, and daytime sleepiness impacted outcomes. Methods: Data sources were the Cumulative Index to Nursing and Allied Health Literature (CINAHL) database, Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE Ovid SP, Scopus, ProQuest, U.S. National Institutes of Health Ongoing Trials Register, and ISRCTN registry (inception until 09-25-2019). Hand searching was undertaken. Two authors independently assessed articles and included trials that randomized adults with a suspected diagnosis of sleep apnea to primary versus specialist management within the same study and reported daytime sleepiness using the Epworth Sleepiness Scale (range 0-24; >10 indicates pathological sleepiness; minimum clinically important difference 2 units) at baseline and follow-up. Results: The primary analysis combined data from 970 (100%) participants (four trials). Risk of bias was assessed (Cochrane Tool). One-stage intention-to-treat analysis showed a slightly smaller decrease in daytime sleepiness (0.8; 0.2 to 1.4), but greater reduction in diastolic blood pressure in primary care (-1.9; -3.2 to -0.6 mm Hg), with similar findings in the per-protocol analysis. Primary care-based within-trial healthcare system costs per participant were lower (-$448.51 U.S.), and quality-adjusted life years and daytime sleepiness improvements were less expensive. Similar primary outcome results were obtained for subgroups in both management settings. Conclusions: Similar outcomes in primary care at a lower cost provide strong support for implementation of primary care-based management of sleep apnea. [ABSTRACT FROM AUTHOR]

Falls-related hospitalization and injury rates are steadily increasing globally due to a growth in the aging population, and the associated health problems that increase risk of falls. One such associated health problem is sleep disturbances and disorders. Recent cohort studies have shown that subjectively reported poor quality sleep is associated with an increased risk of falls. Obstructive sleep apnea (OSA) is a common sleep disorder characterized by the repetitive reductions, or cessation, of airflow. Some studies have shown that OSA impairs posture/balance and gait with nocturnal hypoxemia the likely main cause. Emerging evidence suggests that treating OSA by continuous positive airway pressure (CPAP) can improve gait, but no studies to date have examined the effect of CPAP on posture/balance. The overall control of balance relies on a complex interaction between several physiological functions including vestibular, muscle, visual, and cognitive functions. We postulate that OSA impacts balance by affecting these different systems to various degrees, with the nocturnal hypoxic burden likely playing an important role. Importantly, these impairments in balance/posture and possible falls risk may be alleviated by OSA treatment. Larger mechanistic studies are needed to properly elucidate how OSA affects falls risk and future large-scale randomized control trials are needed to determine the effectiveness of OSA treatment in reducing the risk of falls. [ABSTRACT FROM AUTHOR]

Reduced ventilatory control stability (elevated loop gain) is a key nonanatomical, pathological trait contributing to obstructive sleep apnea (OSA), yet the mechanisms responsible remain unclear. We sought to identify the key factors contributing to elevated loop gain in OSA (controller vs. plant contributions) and to examine whether abnormalities in these factors persist after OSA treatment. In 15 males (8 OSA, 7 height, weight- and age -matched controls), we measured loop gain, controller gain, and plant gain using a pseudorandom binary CO2 stimulation method during wakefulness. Factors potentially influencing plant gain were also assessed (supine lung volume via helium dilution and spirometry). Measures were repeated 2 and 6 wk after initiating continuous positive airway pressure treatment. Loop gain (LG) was higher in OSA versus controls (LG at 1 cycle/min 0.28 ± 0.04 vs. 0.16 ± 0.04, P = 0.046, respectively), and the controller exhibited a greater peak response to CO2 and faster roll-off in OSA. OSA patients also exhibited reduced forced expiratory volume in the first second and forced vital capacity compared with controls (92.2 ± 1.7 vs. 102.9 ± 3.5% predicted, P = 0.021; 93.4 ± 3.1 vs. 106.6 ± 3.6% predicted, P = 0.015, respectively). There was no effect of treatment on any variable. These findings confirm loop gain is higher in untreated OSA patients than in matched controls; however, this was not affected by treatment. NEW & NOTEWORTHY Elevated loop gain contributes to obstructive sleep apnea (OSA) pathophysiology. However, whether loop gain is inherently elevated in OSA or induced by OSA itself, whether it is elevated due to increased chemoreflex sensitivity or obesity-dependent reduced lung volume, and whether it is treatment reversible, are all currently uncertain. This study found loop gain was elevated in OSA versus age-, sex-, height-, and weight-matched controls. However, this was not altered by 6-wk continuous positive airway pressure treatment. [ABSTRACT FROM AUTHOR]

Importance: Sleep apnea (obstructive and central) is associated with adverse cardiovascular risk factors and increased risks of cardiovascular disease. Positive airway pressure (PAP) provides symptomatic relief, whether delivered continuously (CPAP) or as adaptive servo-ventilation (ASV), but the associations with cardiovascular outcomes and death are unclear.Objective: To assess the association of PAP vs control with cardiovascular events and death in patients with sleep apnea.Data Sources and Study Selection: MEDLINE, EMBASE, and the Cochrane Library were systematically searched from inception date to March 2017 for randomized clinical trials that included reporting of major adverse cardiovascular events or deaths.Data Extraction and Synthesis: Two authors independently extracted data using standardized forms. Summary relative risks (RRs), risk differences (RDs) and 95% CIs were obtained using random-effects meta-analysis.Main Outcomes and Measures: The main outcomes were a composite of acute coronary syndrome (ACS) events, stroke, or vascular death (major adverse cardiovascular events); cause-specific vascular events; and death.Results: The analyses included data from 10 trials (9 CPAP; 1 ASV) of patients with sleep apnea (N = 7266; mean age, 60.9 [range, 51.5 to 71.1] years; 5847 [80.5%] men; mean [SD] body mass index, 30.0 [5.2]. Among 356 major adverse cardiovascular events and 613 deaths recorded, there was no significant association of PAP with major adverse cardiovascular events (RR, 0.77 [95% CI, 0.53 to 1.13]; P = .19 and RD, -0.01 [95% CI, -0.03 to 0.01]; P = .23), cardiovascular death (RR, 1.15 [95% CI, 0.88 to 1.50]; P = .30 and RD -0.00 [95% CI, -0.02 to 0.02]; P = .87), or all-cause death (RR, 1.13 [95% CI, 0.99 to 1.29]; P = .08 and RD, 0.00 [95% CI, -0.01 to 0.01]; P = .51). The same was true for ACS, stroke, and heart failure. There was no evidence of different associations for CPAP vs ASV (all P value homogeneity >.24), and meta-regressions identified no associations of PAP with outcomes for different levels of apnea severity, follow-up duration, or adherence to PAP (all P values > .13).Conclusions and Relevance: The use of PAP, compared with no treatment or sham, was not associated with reduced risks of cardiovascular outcomes or death for patients with sleep apnea. Although there are other benefits of treatment with PAP for sleep apnea, these findings do not support treatment with PAP with a goal of prevention of these outcomes. [ABSTRACT FROM AUTHOR]

Insomnia and sleep apnoea are the two most common sleep disorders, found in 6% and 23-50% of the general population respectively. These disorders also frequently co-occur, with 39-58% of sleep apnoea patients reporting symptoms indicative of co-morbid insomnia. When these disorders co-occur, clinicians are faced with difficult treatment decisions, patients experience the additive detrimental impacts of both disorders, and the effectiveness of discrete treatments for each disorder may be impaired. A common finding is that co-morbid insomnia and sleep apnoea (COMISA) is more difficult to treat than either disorder presenting alone. Co-morbid insomnia reduces the initial acceptance of, and later adherence to, continuous positive airway pressure (CPAP) therapy for obstructive sleep apnoea. This has resulted in recent recommendations that treatment approaches should initially target COMISA patients' insomnia to remove this barrier to CPAP treatment, and improve patient outcomes. However, no randomised controlled trial outcomes investigating this treatment approach currently exist. The current article aims to review and integrate recent research examining the prevalence, characteristics, and theoretical mechanistic relationships between co-occurring insomnia and OSA, and discuss previous treatment attempts. [ABSTRACT FROM AUTHOR]

Background: The clinical utility of limited-channel sleep studies (which are increasingly conducted at home) versus laboratory polysomnography (PSG) for diagnosing obstructive sleep apnea (OSA) is unclear.Objective: To compare patient outcomes after PSG versus limited-channel studies.Design: Multicenter, randomized, noninferiority study. (Australian New Zealand Clinical Trials Registry: ACTRN12611000926932).Setting: 7 academic sleep centers.Participants: Patients (n = 406) aged 25 to 80 years with suspected OSA.Intervention: Sleep study information disclosed to sleep physicians comprised level 1 (L1) PSG data (n = 135); level 3 (L3), which included airflow, thoracoabdominal bands, body position, electrocardiography, and oxygen saturation (n = 136); or level 4 (L4), which included oxygen saturation and heart rate (n = 135).Measurements: The primary outcome was change in Functional Outcomes of Sleep Questionnaire (FOSQ) score at 4 months. Secondary outcomes included the Epworth Sleepiness Scale (ESS), the Sleep Apnea Symptoms Questionnaire (SASQ), continuous positive airway pressure (CPAP) compliance, and physician decision making.Results: Change in FOSQ score was not inferior for L3 (mean difference [MD], 0.01 [95% CI, -0.47 to 0.49; P = 0.96]) or L4 (MD, -0.46 [CI, -0.94 to 0.02; P = 0.058]) versus L1 (noninferiority margin [NIM], -1.0). Compared with L1, change in ESS score was not inferior for L3 (MD, 0.08 [CI, -0.98 to 1.13; P = 0.89]) but was inconclusive for L4 (MD, 1.30 [CI, 0.26 to 2.35; P = 0.015]) (NIM, 2.0). For L4 versus L1, there was less improvement in SASQ score (-17.8 vs. -24.7; P = 0.018), less CPAP use (4.5 vs. 5.3 hours per night; P = 0.04), and lower physician diagnostic confidence (P = 0.003).Limitation: Limited-channel studies were simulated by extracting laboratory PSG data and were not done in the home.Conclusion: The results support manually scored L3 testing in routine practice. Poorer outcomes with L4 testing may relate, in part, to reduced physician confidence.Primary Funding Source: National Health and Medical Research Council and Repat Foundation. [ABSTRACT FROM AUTHOR]

Data on the prevalence of obstructive sleep apnea in subjects with type 2 diabetes mellitus in China is scarce. We conducted a multi-centre, cross-sectional study involving 12 hospitals from six regional cities to investigate the prevalence of obstructive sleep apnea in hospitalized patients with type 2 diabetes mellitus and to explore the association between obstructive sleep apnea and related risk factors, diabetic complications and comorbidities in China. Each hospital recruited at least 70 consecutive patients with type 2 diabetes mellitus who were admitted to the endocrinology ward. A total of 880 participants were enrolled and administered overnight sleep monitoring with a portable monitor (ApneaLink™, ResMed, San Diego, CA, USA); other information was collected from medical charts and a standardized questionnaire. In this study, 60.0% (95% confidence interval: 56.8%, 63.2%) of hospitalized patients in China with type 2 diabetes mellitus had comorbid obstructive sleep apnea (apnea-hypopnea index ≥ 5). Only 1.5% (eight of 528) of the patients with both conditions had been diagnosed previously with obstructive sleep apnea. The prevalence of moderate-severe (apnea-hypopnea index ≥ 15) and severe obstructive sleep apnea (apnea-hypopnea index ≥ 30) was estimated to be 25.6% (22.7, 28.5%) and 10.3% (8.3, 12.4%), respectively. Age, sex, body mass index, snoring, reported breath-holding in sleep or gasping or choking arousal, sleepiness, diabetes duration, hypertension, diabetic nephropathy and cardiovascular diseases history were correlated significantly with the severity of obstructive sleep apnea. In China, the prevalence of obstructive sleep apnea in hospitalized patients with type 2 diabetes mellitus is high. Routine screening for and treatment of obstructive sleep apnea is an important, but often neglected, part of the management of diabetes. [ABSTRACT FROM AUTHOR]

The high prevalence of obstructive sleep apnoea ( OSA) and increasing awareness of its potential health consequences has placed significant pressure on laboratory-based sleep services leading to growing waiting lists and delays in diagnosis and treatment. Consequently, there has been increasing interest in the use of simplified, ambulatory models of care involving clinical prediction tools, portable sleep monitoring and home autotitrating continuous positive airway pressure. Researchers are also exploring the potential role for a wider range of health-care providers, including trained nurses and general practitioners, in the primary management of OSA. Recent randomized, controlled studies evaluating the clinical effectiveness of ambulatory management strategies versus traditional laboratory-based care for patients with OSA have consistently demonstrated that comparable patient outcomes can be achieved. The cost-effectiveness of these strategies is currently being debated, and further research examining the long-term economic implications of ambulatory models of care is needed. [ABSTRACT FROM AUTHOR]

Introduction: Nocturnal hypoxemia is associated with increased cardiovascular mortality. Here, we assess whether positive airway pressure by adaptive servo-ventilation (ASV) reduces nocturnal hypoxemic burden in patients with primary central sleep apnea (primary CSA), or heart failure related central sleep apnea (CSA-HF) and treatment emergent central sleep apnea (TECSA).Methods: Overnight oximetry data from 328 consecutive patients who underwent ASV initiation between March 2010 and May 2018 were retrospectively analyzed. Patients were stratified into three groups: primary CSA (n = 14), CSA-HF (n = 31), TECSA (n = 129). Apnea hypopnea index (AHI) and time spent below 90% SpO2 (T90) was measured. Additionally, T90 due to acute episodic desaturations (T90Desaturation) and due to non-specific and non-cyclic drifts of SpO2 (T90Non-specific) were assessed.Results: ASV reduced the AHI below 15/h in all groups. ASV treatment significantly shortened T90 in all three etiologies to a similar extent. T90Desaturation, but not T90Non-specific, was reduced by ASV across all three patient groups. AHI was identified as an independent modulator for ΔT90Desaturation upon ASV treatment (B (95% CI: -1.32 (-1.73; -0.91), p < 0.001), but not for ΔT90 or ΔT90Non-specific. Body mass index was one independent predictor of T90.Conclusions: Across different central sleep apnea etiologies, ASV reduced AHI, but nocturnal hypoxemic burden remained high due to a non-specific component of T90 not related to episodic desaturation. Whether adjunct risk factor management such as weight-loss can further reduce T90 warrants further study. [ABSTRACT FROM AUTHOR]