Continuous positive airway pressure improves sleepiness but not calculated vascular risk in patients with minimally symptomatic obstructive sleep apnoea: the MOSAIC randomised controlled trial

Association between Upper-airway Surgery and Ameliorative Risk Markers of Endothelial Function in Obstructive Sleep Apnea

The objective of our study was to evaluate the effects of upper-airway surgery on improvement of endothelial function-related markers in patients with obstructive sleep apnea (OSA). Subjects with moderate to severe OSA who underwent upper-airway surgery, with a follow-up duration of at least 6 months, were included. Pre- and postoperative polysomnographic variables and endothelial function-related markers were compared. Subgroup and correlation analyses were conducted to find possible indicators for better endothelial function-related markers after upper-airway surgery. In total, 44 patients with OSA were included. The mean follow-up duration was 1.72 ± 0.92 years. Serum VEGFA [-20.29 (CI: -35.27, -5.31), p < 0.05], Ang2 [-0.06 (CI: -0.16, 0.03), p < 0.05], E-selectin [-7.21 (CI: -11.01, -3.41), p < 0.001], VWF [-58.83 (CI: -103.93, -13.73), p < 0.05], VWFCP [-33.52 (CI: -66.34, -0.70), p < 0.05], and TM [-0.06 (CI: -0.09, -0.03), p < 0.05] were significantly lower after upper-airway surgery. However, other risk markers of endothelial function, such as Ang1, ICAM1, VEGFR1, and VCAM, did not change significantly. Correlations between improved endothelial function-related markers and ameliorated oxyhemoglobin saturation and glucolipid metabolism were established. Upper-airway surgery might be associated with an improvement in endothelial function in patients with OSA. These changes may be associated with improved oxygen saturation after upper-airway surgery.

Non-sleepy obstructive sleep apnoea: to treat or not to treat?

Non-sleepy obstructive sleep apnoea (OSA) is thought to have a prevalence of around 20-25% in industrialised countries. However, the question of whether it should be routinely treated or not is controversial. This review collates the results from recent randomised controlled trials addressing OSA and examines whether treating the condition leads to improvements in quality of life and reduced cardiometabolic dysfunction, comorbidities generally attributed to untreated obstructive sleep apnoea/hypopnoea syndrome.

Effects of suboptimal adherence of CPAP therapy on symptoms of obstructive sleep apnoea: a randomised, double-blind, controlled trial

Introduction

Continuous positive airway pressure (CPAP) is currently the treatment of choice for sleepiness in patients with obstructive sleep apnoea (OSA); however, adherence is often thought to be suboptimal. We investigated the effects of suboptimal CPAP usage on objective and subjective sleepiness parameters in patients with OSA.

Material and methods

In this 2-week, parallel, double-blind, randomised controlled trial we enrolled moderate-to-severe OSA patients with excessive pre-treatment daytime sleepiness (Epworth sleepiness scale (ESS) score >10 points) who had suboptimal CPAP adherence over ≥12 months (mean nightly usage time 3–4 h). Patients were allocated through minimisation to either subtherapeutic CPAP (“sham CPAP”) or continuation of CPAP (“therapeutic CPAP”). A Bayesian analysis with historical priors calculated the posterior probability of superiority.

Results

Between May, 2016 and November, 2018, 57 patients (aged 60±8 years, 79% male, 93% Caucasian) were allocated in total, and 52 who completed the study (50% in each arm) were included in the final analysis. The unadjusted ESS score increase was 2.4 points (95% CI 0.6–4.2, p=0.01) in the sham-CPAP group when compared to continuing therapeutic CPAP. The probability of superiority of therapeutic CPAP over sham CPAP was 90.4% for ESS, 90.1% for systolic blood pressure and 80.3% for diastolic blood pressure.

Conclusions

Patients with moderate-to-severe OSA and daytime sleepiness are still getting a substantial benefit from suboptimal CPAP adherence, albeit not as much as they might get if they adhered more. Whether a similar statement can be made for even lower adherence levels remains to be established in future trials.

Continuous positive airway pressure versus standard care for the treatment of people with mild obstructive sleep apnoea (MERGE): a multicentre, randomised controlled trial

BACKGROUND

The evidence base for the treatment of mild obstructive sleep apnoea is limited and definitions of disease severity vary. The MERGE trial investigated the clinical effectiveness of continuous positive airway pressure in patients with mild obstructive sleep apnoea.

METHODS

MERGE, a multicentre, parallel, randomised controlled trial enrolled patients (≥18 years to ≤80 years) with mild obstructive sleep apnoea (apnoea-hypopnoea index [AHI] ≥5 to ≤15 events per h using either AASM 2007 or AASM 2012 scoring criteria) from 11 UK sleep centres. Participants were assigned (1:1) to either 3 months of continuous positive airway pressure plus standard care (sleep counselling), or standard care alone, by computer-generated randomisation; neither participants nor researchers were blinded. The primary outcome was a change in the score on the Short Form-36 questionnaire vitality scale in the intention-to-treat population of patients with mild obstructive sleep apnoea diagnosed using the American Academy of Sleep Medicine 2012 scoring criteria. The study is registered with ClinicalTrials.gov, NCT02699463.

FINDINGS

Between Nov 28, 2016 and Feb 12, 2019, 301 patients were recruited and randomised. 233 had mild obstructive sleep apnoea using AASM 2012 criteria and were included in the intention-to-treat analysis: 115 were allocated to receive continuous positive airway pressure and 118 to receive standard care. 209 (90%) of these participants completed the trial. The vitality score significantly increased with a treatment effect of a mean of 10·0 points (95% CI 7·2-12·8; p<0·0001) after 3 months of continuous positive airway pressure, compared with standard care alone (9·2 points [6·8 to 11·6] vs -0·8 points [-3·2 to 1·5]). Using the ANCOVA last-observation-carried-forward analysis, a more conservative estimate, the vitality score also significantly increased with a treatment effect of a mean of 7·5 points (95% CI 5·3 to 9·6; p<0·0001) after 3 months of continuous positive airway pressure, compared with standard care alone (7·5 points [6·0 to 9·0] vs 0·0 points [-1·5 to 1·5]). Three serious adverse events occurred (one allocated to the continuous positive airway pressure group) and all were unrelated to the intervention.

INTERPRETATION

3 months of treatment with continuous positive airway pressure improved the quality of life in patients with mild obstructive sleep apnoea. These results highlight the need for health-care professionals and providers to consider treatment for patients with mild obstructive sleep apnoea.

FUNDING

ResMed Ltd.

Effects of continuous positive airway pressure on blood pressure in obstructive sleep apnea patients: The Apnea Positive Pressure Long-term Efficacy Study (APPLES)

Obstructive sleep apnea is associated with hypertension, and short-term studies have demonstrated a modest reduction in blood pressure with continuous positive airway pressure therapy. We evaluated the effects of continuous positive airway pressure versus sham continuous positive airway pressure on blood pressure in 1,101 participants with obstructive sleep apnea from the Apnea Positive Pressure Long-term Efficacy Study, a randomized, sham-controlled double-blinded study designed to assess the impact of continuous positive airway pressure on neurocognition. Participants with apnea-hypopnea index ≥ 10 were randomly assigned to continuous positive airway pressure or sham continuous positive airway pressure. Blood pressures measured in the morning and evening at baseline, 2 months and 6 months were analysed post hoc using a mixed-model repeated-measures analysis of variance. The largest magnitude reduction was approximately 2.4 mmHg in morning systolic pressure that occurred at 2 months in the continuous positive airway pressure arm as compared with an approximate 0.5 mmHg reduction in the sham group (continuous positive airway pressure effect -1.9 mmHg, p = .008). At 6 months, the difference between groups was diminished and no longer statistically significant (continuous positive airway pressure effect -0.9 mmHg, p = .12). Sensitivity analysis with use of multiple imputation approaches to account for missing data did not change the results. Treatment with continuous positive airway pressure for obstructive sleep apnea reduces morning but not evening blood pressure in a population with well-controlled blood pressure. The effect was greater after 2 than after 6 months of treatment.

Sleep Apnea and Sleep Habits: Relationships with Metabolic Syndrome

Excess visceral adiposity is a primary cause of metabolic syndrome and often results from excess caloric intake and a lack of physical activity. Beyond these well-known etiologic factors, however, sleep habits and sleep apnea also seem to contribute to abdominal obesity and metabolic syndrome: Evidence suggests that sleep deprivation and behaviors linked to evening chronotype and social jetlag affect eating behaviors like meal preferences and eating times. When circadian rest and activity rhythms are disrupted, hormonal and metabolic regulations also become desynchronized, and this is known to contribute to the development of metabolic syndrome. The metabolic consequences of obstructive sleep apnea syndrome (OSAS) also contribute to incident metabolic syndrome. These observations, along with the first sleep intervention studies, have demonstrated that sleep is a relevant lifestyle factor that needs to be addressed along with diet and physical activity. Personalized lifestyle interventions should be tested in subjects with metabolic syndrome, based on their specific diet and physical activity habits, but also according to their circadian preference. The present review therefore focuses (i) on the role of sleep habits in the development of metabolic syndrome, (ii) on the reciprocal relationship between sleep apnea and metabolic syndrome, and (iii) on the results of sleep intervention studies.

Predictors of long-term adherence to continuous positive airway pressure in patients with obstructive sleep apnea and cardiovascular disease

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).

Feasibility of Single Channel Oximetry for Mass Screening of Obstructive Sleep Apnea

BACKGROUND

The growing awareness for the high prevalence of obstructive sleep apnea (OSA) coupled with the dramatic proportion of undiagnosed individuals motivates the elaboration of a simple but accurate screening test. This study assesses, for the first time, the performance of oximetry combined with demographic information as a screening tool for identifying OSA in a representative (i.e. non-referred) population sample.

METHODS

A polysomnography (PSG) clinical database of 887 individuals from a representative population sample of São Paulo's city (Brazil) was used. Using features derived from the oxygen saturation signal during sleep periods and demographic information, a logistic regression model (termed OxyDOSA) was trained to distinguish between non-OSA and OSA individuals (mild, moderate, and severe). The OxyDOSA model performance was assessed against the PSG-based diagnosis of OSA (AASM 2017) and compared to the NoSAS and STOP-BANG questionnaires.

FINDINGS

The OxyDOSA model had mean AUROC = 0.94 ± 0.02, Se = 0.87 ± 0.04 and Sp = 0.85 ± 0.03. In particular, it did not miss any of the 75 severe OSA individuals. In comparison, the NoSAS questionnaire had AUROC = 0.83 ± 0.03, and missed 23/75 severe OSA individuals. The STOP-BANG had AUROC = 0.77 ± 0.04 and missed 14/75 severe OSA individuals.

INTERPRETATION

We provide strong evidence on a representative population sample that oximetry biomarkers combined with few demographic information, the OxyDOSA model, is an effective screening tool for OSA. Our results suggest that sleep questionnaires should be used with caution for OSA screening as they fail to identify many moderate and even some severe cases. The OxyDOSA model will need to be further validated on data recorded using overnight portable oximetry.

Treatment of Adult Obstructive Sleep Apnea With Positive Airway Pressure: An American Academy of Sleep Medicine Systematic Review, Meta-Analysis, and GRADE Assessment

INTRODUCTION

The purpose of this systematic review is to provide supporting evidence for the clinical practice guideline for the treatment of obstructive sleep apnea (OSA) in adults using positive airway pressure (PAP).

METHODS

The American Academy of Sleep Medicine commissioned a task force of experts in sleep medicine. A systematic review was conducted to identify studies that compared the use of PAP with no treatment as well as studies that compared different PAP modalities. Meta-analyses were performed to determine the clinical significance of using PAP in several modalities (ie, continuous PAP, auto-adjusting PAP, and bilevel PAP), to treat OSA in adults. In addition, meta-analyses were performed to determine the clinical significance of using an in-laboratory versus ambulatory strategy for the initiation of PAP, educational and behavioral interventions, telemonitoring, humidification, different mask interfaces, and flexible or modified pressure profile PAP in conjunction with PAP to treat OSA in adults. Finally, the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) process was used to assess the evidence for making recommendations.

RESULTS

The literature search resulted in 336 studies that met inclusion criteria; 184 studies provided data suitable for meta-analyses. The data demonstrated that PAP compared to no treatment results in a clinically significant reduction in disease severity, sleepiness, blood pressure, and motor vehicle accidents, and improvement in sleep-related quality of life in adults with OSA. In addition, the initiation of PAP in the home demonstrated equivalent effects on patient outcomes when compared to an in-laboratory titration approach. The data also demonstrated that the use of auto-adjusting or bilevel PAP did not result in clinically significant differences in patient outcomes compared with standard continuous PAP. Furthermore, data demonstrated a clinically significant improvement in PAP adherence with the use of educational, behavioral, troubleshooting, and telemonitoring interventions. Systematic reviews for specific PAP delivery method were also performed and suggested that nasal interfaces compared to oronasal interfaces have improved adherence and slightly greater reductions in OSA severity, heated humidification compared to no humidification reduces some continuous PAP-related side effects, and pressure profile PAP did not result in clinically significant differences in patient outcomes compared with standard continuous PAP.

Good long-term adherence to continuous positive airway pressure therapy in patients with resistant hypertension and sleep apnea

Although adequate adherence is paramount in achieving the beneficial effects of continuous positive airway pressure therapy in patients with obstructive sleep apnea, long-term adherence and the variables involved in continuous positive airway pressure compliance in patients with resistant hypertension and obstructive sleep apnea are yet unknown. We conducted a prospective, multicentre, observational study in 177 patients recruited from hypertensive units with resistant hypertension confirmed by means of 24-hr blood pressure monitoring (blood pressure ≥ 130 and/or ≥ 80 mmHg, despite taking at least three antihypertensive drugs or < 130/80 mmHg with > 3 drugs) and obstructive sleep apnea (apnea-hypopnea index ≥ 5 in a respiratory polygraph) who were prescribed continuous positive airway pressure treatment. Good adherence was defined as an average cumulative continuous positive airway pressure use of ≥ 4 hr per night at the end of the follow-up. A multivariate Cox regression analysis was performed to identify independent predictors of continuous positive airway pressure adherence. Patients were followed for a median of 57.6 (42-72) months after initiating continuous positive airway pressure therapy. At the end of the follow-up, the median continuous positive airway pressure use was 5.7 (inter-quartile range 3.9-6.6) hr per night, and 132 patients (74.5%) showed good continuous positive airway pressure adherence. The only baseline variable associated with poor adherence was the presence of previous stroke (hazard ratio 4.00, 95% confidence interval 1.92-8.31). Adequate adherence at 1 month also predicted good adherence at the end of the follow-up (hazard ratio 14.4, 95% confidence interval 4.94-56). Both variables also predicted adherence at a threshold of 6 hr per night. Our results show that good continuous positive airway pressure adherence is an achievable and feasible goal in patients with resistant hypertension and obstructive sleep apnea. Previous stroke and short-term adherence predicted long-term adherence.

Effects of CPAP on Testosterone Levels in Patients With Obstructive Sleep Apnea: A Meta-Analysis Study

Background: Obstructive sleep apnea (OSA) represents a frequent complication among patients with obesity and has been associated with neuroendocrine changes, including hypogonadism. Objective: We conducted a systematic review and meta-analysis to evaluate the effects of continuous positive airway pressure (CPAP) on testosterone and gonadotropins in male patients with OSA. Methods: The review was registered on PROSPERO (CRD42018103164). PubMed, Scopus, CENTRAL, and Clinicaltrials.gov were searched until June 2018. Studies reporting the effect of CPAP on total testosterone, free testosterone, sexual hormone binding globulin (SHBG), follicle stimulating hormone (FSH), luteinizing hormone (LH), and prolactin were included. A subgroup analysis on hypogonadal vs. eugonadal status at baseline was performed. Results: Out of 129 retrieved papers, 10 prospective cohort and 2 randomized controlled studies were included in the review. Three hundred eighty-eight patients were included. CPAP use was not associated with a significant change in total testosterone levels [mean difference 1.08, 95% confidence interval (CI) -0.48 to 2.64] or other outcomes. The subgroup analysis confirmed the overall results. Conclusions: The present review does not support the hypothesis of a direct interaction between OSA and testosterone. Strategies other than CPAP should therefore be considered in managing hypogonadism in patients with OSA.

Systemic hypertension in obstructive sleep apnea

There is consistent epidemiological evidence that sleep disordered breathing and systemic arterial hypertension are deeply associated, being linked through a bidirectional complex interaction among multiple mechanisms including autonomic nervous system alterations, inflammation, hormonal and hemodynamic components, sleep alterations. However there are several unanswered questions not only from a pathophysiological perspective, but also regarding the effects of obstructive sleep apnea (OSA) treatment on arterial blood pressure values. At present, while many studies have supported the possibility to obtain at least a small blood pressure reduction with OSA treatment, in particular in hypertensive patients, large trials have not clearly confirmed a significant anti-hypertensive effect, nor a beneficial effect of this intervention on cardiovascular endpoints including cardiovascular mortality. Aim of the present review article is to address the relationship between OSA and hypertension in the light of the latest evidence in the field. Moreover we will discuss research topics which need to be investigated in the future, in order to better clarify still pending issues with the aim of obtaining an early diagnosis, a more suitable phenotyping including comorbidities, and better strategies to improve patients' compliance and adherence to treatment.

Comparing different ways of calculating sample size for two independent means: A worked example

We discuss different methods of sample size calculation for two independent means, aiming to provide insight into the calculation of sample size at the design stage of a parallel two-arm randomised controlled trial (RCT). We compare different methods for sample size calculation, using published results from a previous RCT. We use variances and correlation coefficients to compare sample sizes using different methods, including

1. The choice of the primary outcome measure: post-intervention score vs. change from baseline score.

2. The choice of statistical methods: t-test without using correlation coefficients vs. analysis of covariance (ANCOVA).

We show that the required sample size will depend on whether the outcome measure is the post-intervention score, or the change from baseline score, with or without baseline score included as a covariate. We show that certain assumptions have to be met when using simplified sample size equations, and discuss their implications in sample size calculation when planning an RCT. We strongly recommend publishing the crucial result “mean change (SE, standard error)” in a study paper, because it allows (i) the calculation of the variance of the change score in each arm, and (ii) to pool the variances from both arms. It also enables us to calculate the correlation coefficient in each arm. This subsequently allows us to calculate sample size using change score as the outcome measure. We use simulation to demonstrate how sample sizes by different methods are influenced by the strength of the correlation.

Continuous positive airway pressure for adults with obstructive sleep apnea and cardiovascular disease: a meta-analysis of randomized trials

BACKGROUND

It remains uncertain whether continuous positive airway pressure (CPAP) therapy would significantly impact hard clinical outcomes in patients with obstructive sleep apnea (OSA). This meta-analysis aimed to assess the effects of CPAP in survival and secondary prevention of major cardiovascular events in patients with OSA and cardiovascular disease (CVD).

METHODS

PubMed, Cochrane CENTRAL, LILACS, and SciElo databases (up to January 2018) were searched for randomized trials that compared CPAP with no active treatment in adults with OSA and CVD. The primary outcomes were all-cause death, cardiovascular death, acute myocardial infarction, stroke, and any major cardiovascular event. We used risk ratios (RR) and 95% confidence interval (CI) as the effect measures for dichotomous data, and weighted mean difference (WMD) and 95% CI for continuous variables. We used the random-effects method for meta-analysis.

RESULTS

Nine trials involving 3314 patients contributed data for meta-analysis of at least one outcome. The duration (median) of CPAP treatment varied from one month to 56.9 months. The pooled RR (95% CI) was 0.86 (0.60-1.23, I² = 0.0%) for all-cause death, 0.58 (0.19-1.74, I² = 47%) for cardiovascular death, 1.11 (0.76-1.62, I² = 0.0%) for myocardial infarction, 0.77 (0.46-1.28, I² = 16%) for stroke, and 0.93 (0.70-1.24, I² = 49%) for any major cardiovascular event. The quality of evidence for these outcomes was low.

CONCLUSIONS

Low-quality evidence suggests that CPAP therapy does not significantly improve survival or prevent major cardiovascular events in adults with OSA and cardiovascular disease.

A consensus opinion amongst stakeholders as to benefits of obstructive sleep apnoea treatment for cardiovascular health

BACKGROUND AND OBJECTIVE

Obstructive sleep apnoea (OSA) is a prevalent sleep disorder associated with increased cardiovascular morbidity and mortality. Whether treatment of OSA improves cardiovascular risk remains controversial. Our aim was to determine a consensus opinion of key sleep medicine stakeholder groups as to the cardiovascular benefits of treating moderate-severe OSA.

METHODS

A multidisciplinary panel was assembled from representatives from the Australasian Sleep Association, Sleep Health Foundation, Australasian Sleep Technologists Association, the Sleep Health Foundation Business Council and the Sleep Disorders Australia patient support group. Three statements reflecting areas of controversy related to cardiovascular benefits of OSA treatment were created. A modified RAND/UCLA appropriateness methodology was applied determining the panel's level of consensus and agreement with each statement.

RESULTS

Voting results indicated the panel: (1) remained unsure whether moderate-severe OSA treatment improves rates of cardiovascular events/death, (2) agreed that moderate-severe OSA treatment improves blood pressure in patients with hypertension and (3) mostly agreed that moderate-severe OSA treatment improves left ventricular function in patients with heart failure. Consensus of opinion was achieved for statements (1) and (2), but was narrowly missed for statement (3).

CONCLUSION

The panel believed that findings from large-scale randomized trials indicate that treatment of moderate-severe OSA has not been established to improve cardiovascular event or morbidity/mortality rates. Strong evidence supports the ability of treatment to reduce blood pressure. Whilst many panel members believed that treatment improves left ventricular function, some were uncertain of the clinical significance of this secondary endpoint measure derived from lesser quality evidence.

Continuous positive airway pressure effect on visual acuity in patients with type 2 diabetes and obstructive sleep apnoea: a multicentre randomised controlled trial

We sought to establish whether continuous positive airway pressure (CPAP) for obstructive sleep apnoea (OSA) in people with type 2 diabetes and diabetic macular oedema (DMO) improved visual acuity.We randomly assigned 131 eligible patients aged 30-85 years from 23 UK centres with significant DMO causing visual impairment (LogMAR letters identified ≥39 and ≤78, score 0.92-0.14) plus severe OSA on screening to either usual ophthalmology care (n=67) or usual ophthalmology care plus CPAP (n=64) for 12 months.Mean age of participants was 64 years, 73% male, mean body mass index 35.0 kg·m- 2 Mean 4% oxygen desaturation index was 36 events·h-1 There was no significant difference in the visual acuity at 12 months between the CPAP group and the control group (mean LogMAR 0.33 (95% CI 0.29-0.37) versus 0.31 (95% CI 0.27-0.35); p=0.39), and no significant correlation between change in LogMAR and average CPAP use. The median±sd (range) daily CPAP use was 3.33±2.25 (0-7.93) h at 3 months, 3.19±2.54 (0-8.07) h at 6 months and 3.21±2.70 (0-7.98) h at 12 months.CPAP therapy for OSA did not improve visual acuity in people with type 2 diabetes and DMO compared with usual care alone over 12 months.

Sleep apnea and type 2 diabetes

The aim of the present review was to clarify the association between obstructive sleep apnea (OSA) and type 2 diabetes, and discuss the therapeutic role of continuous positive airway pressure (CPAP) in type 2 diabetes. OSA patients are more likely than non-OSA populations to develop type 2 diabetes, while more than half of type 2 diabetes patients suffer from OSA. Similar to Western countries, in the East Asian population, the association between these two disorders has also been reported. CPAP is the primary treatment for OSA, but the effect of CPAP on comorbid diabetes has not been established. CPAP improved glucose metabolism determined by the oral glucose tolerance test in OSA patients, and several studies have shown that CPAP improves insulin resistance, particularly in obese populations undergoing long-term CPAP. Diabetes is associated with other sleep-related manifestations as well, such as snoring and excessive daytime sleepiness. Snoring is associated with the development of diabetes, and excessive daytime sleepiness appears to modify insulin resistance. Well-designed studies are required to clarify the therapeutic effect of CPAP on diabetes. As both diabetes and OSA lead to cardiovascular disease, clinicians and healthcare professionals should be aware of the association between diabetes and OSA, and should take CPAP and health-related behaviors into consideration when treating patients with diabetes and/or OSA.

Minimum important difference of the Epworth Sleepiness Scale in obstructive sleep apnoea: estimation from three randomised controlled trials

BACKGROUND

The Epworth Sleepiness Scale (ESS) is a widely used tool for assessing sleepiness in patients with obstructive sleep apnoea (OSA). We aimed to estimate the minimal important difference (MID) in patients with OSA.

METHODS

We used individual data from three randomised controlled trials (RCTs) in patients with OSA where the preintervention to postintervention change in ESS was used as a primary outcome. We used anchor-based linear regression and responder analysis approaches to estimate the MID. For anchors, we used the change in domains of the Functional Outcomes of Sleep Questionnaire and 36-Item Short Form Health Survey. We also used the distribution-based approaches Cohen's effect size, SE of measurement and empirical rule effect size to support the anchor-based estimates. The final MID was determined by triangulating all estimates to a single MID.

FINDINGS

A total of 639 patients with OSA were included in our analyses across the three RCTs with a median (IQR) baseline ESS score of 10 (6-13). The median (IQR) ESS change score overall was -2 (-5 to 1). The anchor-based estimates of the MID were between -1.74 and -4.21 points and estimates from the responder analysis were between -1 and -3 points. Distribution-based estimates were smaller, ranging from -1.46 to -2.36.

INTERPRETATION

We propose an MID for the ESS of 2 points in patients with OSA with a disease severity from mild to severe. This estimate provides the means to plan trials and interpret the clinical relevance of changes in ESS.

TRIAL REGISTRATION NUMBER

Provent, NCT01332175; autoCPAP trial, NCT00280800; MOSAIC,ISRCTN (3416388).

Patient experience with upper airway stimulation in the treatment of obstructive sleep apnea

OBJECTIVE

Selective upper airway stimulation (sUAS) is a new treatment modality for patients with obstructive sleep apnea (OSA) and continuous positive airway pressure (CPAP) failure. The aim of this study was to analyze therapy adherence and to structure patient experience reports.

METHODS

Patients from two German implantation centers were included. Besides demographic and OSA characteristics of that cohort, patients answered a questionnaire on subjective sensation of the stimulation, use of different functions, side effects, and an inventory for the description of the attitude towards sUAS. The use of the sUAS was evaluated as a read-out of the implanted system.

RESULTS

The overall apnea-hypopnea-index (AHI) of that 102 assessed patients reduced from initially 32.8/h to 12.6/h at the last available assessment. The responder rate was 75%. There was an objective therapy usage of 5.7 h and subjective reports of 6.8 nights per week. The attitude resulted in strong agreement towards the statement "UAS reduces the problems caused by my sleep apnea". Information on sensing the stimulation and usage habits could be gathered such as that stimulation is only sensed by 67.9% of the patients upon waking in the morning and that 73.6% of the patients do not change the voltage in general.

CONCLUSION

This investigation on the sUAS therapy revealed a high adherence to the therapy. The AHI or daytime sleepiness do not have obvious influence on adherence. Patients expressed a positive attitude towards sUAS. These patient reports upon stimulation experiences are of great help to consult candidates for sUAS in future.

Obstructive Sleep Apnea With or Without Excessive Daytime Sleepiness: Clinical and Experimental Data-Driven Phenotyping

Introduction: Obstructive sleep apnea (OSA) is a serious and prevalent medical condition with major consequences for health and safety. Excessive daytime sleepiness (EDS) is a common-but not universal-accompanying symptom. The purpose of this literature analysis is to understand whether the presence/absence of EDS is associated with different physiopathologic, prognostic, and therapeutic outcomes in OSA patients. Methods: Articles in English published in PubMed, Medline, and EMBASE between January 2000 and June 2017, focusing on no-EDS OSA patients, were critically reviewed. Results: A relevant percentage of OSA patients do not complain of EDS. EDS is a significant and independent predictor of incident cardiovascular disease (CVD) and is associated with all-cause mortality and an increased risk of metabolic syndrome and diabetes. Male gender, younger age, high body mass index, are predictors of EDS. The positive effects of nasal continuous positive airway pressure (CPAP) therapy on blood pressure, insulin resistance, fatal and non-fatal CVD, and endothelial dysfunction risk factors have been demonstrated in EDS-OSA patients, but results are inconsistent in no-EDS patients. The most sustainable cause of EDS is nocturnal hypoxemia and alterations of sleep architecture, including sleep fragmentation. These changes are less evident in no-EDS patients that seem less susceptible to the cortical effects of apneas. Conclusions: There is no consensus if we should consider OSA as a single disease with different phenotypes with or without EDS, or if there are different diseases with different genetic/epigenetic determinants, pathogenic mechanisms, prognosis, and treatment.The small number of studies focused on this issue indicates the need for further research in this area. Clinicians must carefully assess the presence or absence of EDS and decide accordingly the treatment. This approach could improve combination therapy targeted to a patient's specific pathology to enhance both efficacy and long-term adherence to OSA treatment and significantly reduce the social, economic, and health negative impact of OSA.

Cysteinyl-leukotriene pathway as a new therapeutic target for the treatment of atherosclerosis related to obstructive sleep apnea syndrome

AIMS

Obstructive sleep apnea (OSA) characterized by nocturnal intermittent hypoxia (IH) is associated with atherosclerosis and cysteinyl-leukotrienes (CysLT) pathway activation. We aimed to identify the determinants of CysLT pathway activation and the role of CysLT in OSA-related atherosclerosis.

METHODS AND RESULTS

Determinants of the urinary excretion of LTE₄ (U-LTE₄) including history of cardiovascular events, polysomnographic and biological parameters were studied in a cohort of 170 OSA patients and 29 controls, and in a subgroup of OSA patients free of cardiovascular event (n = 136). Mechanisms linking IH, the CysLT pathway and atherogenesis were investigated in Apolipoprotein E deficient (ApoE^-/-) mice exposed to 8-week IH. In the whole cohort, U-LTE₄ was independently influenced by age, minimal oxygen saturation, and a history of cardiovascular events, and correlated significantly with intima-media thickness. In the subgroup of OSA patients free of cardiovascular event, increased U-LTE₄ was increased compared to controls and independently related to hypoxia severity and traditional risk factors aggregated in the 10-year cardiovascular risk score of European Society of Cardiology. In IH mice, atherosclerosis lesion size and mRNA levels of 5-lipoxygenase, 5-lipoxygenase activating protein (FLAP) and CysLT₁ receptor were significantly increased. This transcriptional activation was associated with the binding of HIF-1 to the FLAP promoter and was strongly associated with atherosclerosis lesion size. CysLT₁ receptor antagonism (montelukast) significantly reduced atherosclerosis progression in IH mice.

CONCLUSIONS

IH-related CysLT pathway activation contributes to OSA-induced atherogenesis. In the era of personalized medicine, U-LTE₄ may be a useful biomarker to identify OSA patients for whom CysLT₁ blockade could represent a new therapeutic avenue for reducing cardiovascular risk.

Continuous Positive Airway Pressure Reduces Night-Time Blood Pressure and Heart Rate in Patients With Obstructive Sleep Apnea and Resistant Hypertension: The RHOOSAS Randomized Controlled Trial

Objective

Most patients with resistant hypertension (RH) have obstructive sleep apnea (OSA). We aimed to determine the impact of OSA and continuous positive airway pressure (CPAP) treatment on the leptin profile and blood pressure (BP) in patients with RH.

Methods

After an initial case-control study (RH with and without OSA), we performed a randomized, single blind study in OSA + RH patients receiving either sham CPAP (3 months) followed by active CPAP (6 months) or 6 months of active CPAP. The primary outcome was the comparison of leptin levels between groups of RH patients with or without OSA. Secondary outcomes were the comparison of metabolic parameters, biomarkers of sympathetic activity, and BP indices between the two groups of RH patients with or without OSA. The same outcomes were then evaluated and compared before and after sham and effective CPAP intervention.

Results

Sixty-two patients (60 ± 10 years; 77% men) with RH (24-h daytime systolic BP (SBP)/diastolic BP: 145 ± 13/85 ± 10 mmHg, 3.7 antihypertensive drugs) were included. The 37 RH patients exhibiting OSA (60%) were predominantly men (87 vs 64% for non-OSA patients), with a greater prevalence of metabolic syndrome and higher creatininemia. Their leptin concentrations were significantly lower than in non-OSA patients [9 (6; 15) vs 17 (6; 29) ng/mL] but increased after 6 months of CPAP. Three months of effective CPAP significantly decreased night-time SBP by 6.4 mmHg and heart rate (HR) by 6.0 bpm, compared to sham CPAP.

Conclusion

The association between OSA and RH corresponds to a specific, predominately male phenotype with a higher burden of metabolic syndrome and higher creatininemia but there was no significant difference between OSA and non-OSA patients regarding BP indices, and the number of antihypertensive drugs used. Active CPAP could be efficient at decreasing night-time BP and HR, but there was no difference between CPAP and sham CPAP groups for all metabolic and SNS markers (NCT00746902 RHOOSAS).

Severity of OSAS, CPAP and cardiovascular events: A follow-up study

BACKGROUND

Previous studies suggested obstructive sleep apnoea syndrome (OSAS) as a major risk factor for incident cardiovascular events. However, the relationship between OSAS severity, the use of continuous positive airway pressure (CPAP) treatment and the development of cardiovascular disease is still matter of debate.

STUDY OBJECTIVES

The aim was to test the association between OSAS and cardiovascular events in patients with concomitant cardio-metabolic diseases and the potential impact of CPAP therapy on cardiovascular outcomes.

METHODS

Prospective observational cohort study of consecutive outpatients with suspected metabolic disorders who had complete clinical and biochemical workup including polysomnography because of heavy snoring and possible OSAS. The primary endpoint was a composite of major adverse cardiovascular and cerebrovascular events (MACCE).

RESULTS

Median follow-up was 81.3 months, including 434 patients (2701.2 person/years); 83 had a primary snoring, 84 had mild, 93 moderate and 174 severe OSAS, respectively. The incidence of MACCE was 0.8% per year (95% confidence interval [CI] 0.2-2.1) in primary snorers and 2.1% per year (95% CI 1.5-2.8) for those with OSAS. A positive association was observed between event-free survival and OSAS severity (log-rank test; P = .041). A multivariable Cox regression analysis showed obesity (HR = 8.011, 95% CI 1.071-59.922, P = .043), moderate OSAS (vs non-OSAS HR = 3.853, 95% CI 1.069-13.879, P = .039) and severe OSAS (vs non-OSAS HR = 3.540, 95% CI 1.026-12.217, P = .045) as predictors of MACCE. No significant association was observed between CPAP treatment and MACCE (log-rank test; P = .227).

CONCLUSIONS

Our findings support the role of moderate/severe OSAS as a risk factor for incident MACCE. CPAP treatment was not associated with a lower rate of MACCE.

Obstructive sleep apnoea

Obstructive sleep apnoea (OSA) is increasing in prevalence due to rising obesity. While OSA is a disorder primarily of the upper airway during sleep, its pathophysiological impact on other body systems is increasingly recognised. There has been interest in the prevalence of OSA in different ophthalmic conditions and possible causation has been postulated. As OSA is common, it can be expected that people with co-existent OSA will be found in any ophthalmic disease population studied. To determine with confidence the significance of finding patients with OSA in a particular cohort requires a well matched control group, ideally matched for age, obesity, gender and co-morbidities. Only if one can say with certainty that the prevalence of OSA is higher in a group with a particular co-existent ophthalmic disease can we begin to speculate about possible mechanisms for the overlap in these conditions. Possible mechanisms for how OSA might affect the eye are discussed in this review. The current literature is reviewed with respect to diabetic retinopathy, glaucoma, floppy eyelid syndrome, non-arteritic ischaemic optic neuropathy, keratoconus and AMD. Associations with OSA have been found, but robust prospective studies using multi-channel sleep studies to diagnose OSA are lacking. Gaps remain in the evidence and in our knowledge. It is hoped that this review will highlight the need for ophthalmologists to consider OSA in their patients. It also makes recommendations for future research, especially to consider whether therapies for OSA can also be effective for ophthalmic disorders.

Obstructive Sleep Apnea and the Impact on Surgical Outcomes in Gynecology

Importance

Obstructive sleep apnea syndrome (OSAS) is a common medical condition in the United States and affects gynecologic surgical outcomes.

Objective

The aim of this review was to improve perioperative diagnosis and management of OSAS in patients presenting for gynecologic surgery and ultimately improve perioperative outcomes. The role of preoperative evaluation and screening is also addressed.

Evidence Acquisition

Medical databases were queried for publications pertaining to OSAS complications, risk factors, screening, and perioperative management. Pertinent articles were reviewed by the study authors.

Results

Obstructive sleep apnea syndrome is underdiagnosed in the preoperative surgical population. Obesity and other risk factors for OSAS are prevalent in patients with gynecologic issues but are not fully assessed with screening prior to surgery. Effective treatment modalities, such as continuous positive airway pressure, and perioperative management strategies are available to improve patient outcomes.

Conclusions and Relevance

Increased diagnosis and treatment for OSAS in the perioperative period can improve perioperative outcomes, surgical outcomes, and long-term patient outcomes. Strategies to increase effective management in patients presenting for gynecologic surgery are needed.

The acute effect of continuous positive airway pressure titration on blood pressure in awake overweight/obese patients with obstructive sleep apnoea

OBJECTIVES

Continuous positive airway pressure (CPAP) improves upper airway obstruction in patients with obstructive sleep apnoea (OSA), who often are overweight-obese. Although it is thought that CPAP improves long-term blood pressure control (BP), the impact of acute and short-term CPAP use on the cardiovascular system in obese patients has not been described in detail.

METHODS

Obese patients (body mass index, BMI > 25 kg/m²) with OSA were studied awake, supine during incremental CPAP titration (4-20 cmH₂O, +2 cmH₂O/3 mins). BP was measured continuously with a beat-to-beat BP monitor (Ohmeda 2300, Finapres Medical Systems, Amsterdam/NL), BP variability (BPV) was calculated as the standard deviation of BP at each CPAP level, the 95% confidence interval (95%CI) was calculated and changes in BP and BPV were reported.

RESULTS

15 patients (12 male, 48 ± 10) years, BMI 38.9 ± 5.8 kg/m²) were studied; the baseline BP was 131.0 ± 10.2/85.1 ± 9.1 mmHg. BP and BPV increased linearly with CPAP titration (systolic BP r = 0.960, p < .001; diastolic BP r = 0.961, p < .001; systolic BPV r = 0.662, p = .026; diastolic BPV r = 0.886, p < .001). The systolic BP increased by +17% (+23.15 (7.9, 38.4) mmHg; p = .011) and the diastolic BP by +23% (+18.27 (2.33, 34.21) mmHg; p = .009), when titrating CPAP to 20 cmH₂O. Systolic BPV increased by +96% (+5.10 (0.67, 9.53) mmHg; p < .001) and was maximal at 14 cmH₂O, and diastolic BPV by +97% (+3.02 (0.26, 5.78) mmHg; p < .001) at 16 cmH₂O.

CONCLUSION

Short-term incremental CPAP leads to significant increases in BP and BPV in obese patients with OSA while awake. Careful titration of pressures is required to minimise the risk of nocturnal awakenings while improving BP control.

Kinesthetic stimulation for obstructive sleep apnea syndrome: An "on-off" proof of concept trial

Obstructive sleep apnea (OSA) occurs when the upper airway narrows or collapses due to the loss of upper airway muscle activation at sleep onset. This study investigated the effectiveness of triggered kinesthetic stimulation in patients with OSA. This proof-of-concept, open-label, multicenter prospective study was conducted on 24 patients with severe OSA. During a one night evaluation, kinesthetic stimulation was intermittently delivered in 30 minute periods. The duration of apneas and hypopneas during Stim _on and Stim _off periods were compared. Five hospital-based university centers in France participated. Sleep studies were evaluated by a single scorer at a core laboratory (CHU Grenoble). Results show that during the Stim _on phases, statistically significant decreases in durations of apneas and hypopneas were observed in 56% and 46% of patients, respectively. Overall, 75% of patients showed an improvement in apneas or hypopneas durations. The mean reduction in durations for patients with a significant decrease was 4.86 seconds for apneas and 6.00 seconds for hypopneas. This proof of concept study is the first to identify kinesthetic stimulation as a potentially effective therapy for OSA. These data justify evaluation in a controlled study.

Long-term prediction of adherence to continuous positive air pressure therapy for the treatment of moderate/severe obstructive sleep apnea syndrome

BACKGROUND

Continuous positive airway pressure (CPAP) therapy is a highly effective treatment for obstructive sleep apnea syndrome (OSAS). However, poor adherence is a limiting factor, and a significant proportion of patients are unable to tolerate CPAP. The aim of this study was to determine predictors of long-term non-compliance with CPAP.

METHODS

CPAP treatment was prescribed to all consecutive patients with moderate or severe OSAS (AHI ≥15 events/h) (n = 295) who underwent a full-night CPAP titration study at home between February 1, 2002 and December 1, 2016. Adherence was defined as CPAP use for at least 4 h per night and five days per week. Subjects had periodical follow-up visits including clinical and biochemical evaluation and assessment of adherence to CPAP.

RESULTS

Median follow-up observation was 74.8 (24.2/110.9) months. The percentage of OSAS patients adhering to CPAP was 41.4% (42.3% in males and 37.0% in females), and prevalence was significantly higher in severe OSAS than in moderate (51.8% vs. 22.1%; p < 0.001; respectively). At multivariate analysis, lower severity of OSAS (HR = 0.66; CI 95 0.46-0.94) p < 0.023), cigarette smoking (HR = 1.72; CI 95 1.13-2.61); p = 0.011), and previous cardiovascular events (HR = 1.95; CI 95 1.03-3.70; p = 0.04) were the only independent predictors of long-term non-adherence to CPAP after controlling for age, gender, and metabolic syndrome.

CONCLUSIONS

In our cohort of patients with moderate/severe OSAS who were prescribed CPAP therapy, long-term compliance to treatment was present in less than half of the patients. Adherence was positively associated with OSAS severity and negatively associated with cigarette smoking and previous cardiovascular events at baseline.

Sleep Disturbances as a Risk Factor for Stroke

Sleep, a vital process of human being, is carefully orchestrated by the brain and consists of cyclic transitions between rapid eye movement (REM) and non-REM (NREM) sleep. Autonomic tranquility during NREM sleep is characterized by vagal dominance and stable breathing, providing an opportunity for the cardiovascular-neural axis to restore homeostasis, in response to use, distress or fatigue inflicted during wakefulness. Abrupt irregular swings in sympathovagal balance during REM sleep act as phasic loads on the resting cardiovascular system. Any causes of sleep curtailment or fragmentation such as sleep restriction, sleep apnea, insomnia, periodic limb movements during sleep, and shift work, not only impair cardiovascular restoration but also impose a stress on the cardiovascular system. Sleep disturbances have been reported to play a role in the development of stroke and other cardiovascular disorders. This review aims to provide updated information on the role of abnormal sleep in the development of stroke, to discuss the implications of recent research findings, and to help both stroke clinicians and researchers understand the importance of identification and management of sleep pathology for stroke prevention and care.

Adherence to Positive Airway Therapy After Switching From CPAP to ASV: A Big Data Analysis

STUDY OBJECTIVES

There is a lack of data regarding adherence trajectories when switching from continuous positive airway pressure (CPAP) to adaptive servoventilation (ASV) in the context of persistent or treatment-emergent central sleep apnea (CSA). This study investigated 90-day adherence rates in patients with sleep apnea based on the type of positive airway pressure (PAP) device used and any switching of PAP modality over time.

METHODS

Telemonitoring data were obtained from a United States PAP database. Eligible patients were a 30% random sample who started PAP, plus all who started ASV, from January 1, 2015 to October 2, 2015. All received PAP and had at least one session with usage of 1 hour or more. Adherence and device usage were determined in three groups: started on CPAP and stayed on CPAP (CPAP only); started on ASV and stayed on ASV (ASV only); started on CPAP, switched to ASV (Switch). The United States Medicare definition of adherence was used.

RESULTS

The study included 198,890 patients; 189,724 (CPAP only), 8,957 (ASV only) and 209 (Switch). In the Switch group, average apnea-hypopnea index decreased significantly on ASV versus CPAP. At 90 days, adherence rates were 73.8% and 73.2% in the CPAP only and ASV only groups. In the Switch group, CPAP adherence was 62.7%, improving to 76.6% after the switch to ASV. Mean device usage at 90 days was 5.27, 5.31, and 5.73 h/d in the CPAP only, ASV only, and Switch groups, respectively.

CONCLUSIONS

Treatment-emergent or persistent CSA during CPAP reduced therapy adherence, but adherence improved early after switching from CPAP to ASV.

Predictors of long-term adherence to continuous positive airway pressure in patients with obstructive sleep apnoea and acute coronary syndrome

Background

Continuous positive airway pressure (CPAP) is an effective treatment for obstructive sleep apnoea (OSA), but an evaluation of CPAP adherence is rarely carried out among patients with acute coronary syndrome (ACS). The goals of the study are to analyse long-term adherence and identify the predictors of non-compliance with CPAP treatment for patients with non-sleepy OSA and ACS.

Methods

This is an ancillary study of the ISAACC study, which is a multicentre, prospective, open-label, parallel, randomized, and controlled trial (NCT01335087) in patients with hospital admission for ACS. For the purpose of this study, only non-sleepy patients with moderate or severe OSA and randomized to receive CPAP treatment were analysed (n=357). Non-compliance was defined as CPAP dropout or average cumulative CPAP use of <4 hours/night. Multivariable logistic regression analysis was performed to identify predictors of CPAP adherence.

Results

Adherence to treatment was 35.3% at 12 months. According to the unadjusted analysis, higher apnoea-hypopnea index (AHI) (P<0.001) and oxygen desaturation index (ODI) (P=0.001) were associated with a lower risk of non-compliance. Multivariable logistic regression analysis showed that high AHI (P=0.0051), high amounts of smoking pack-year (P=0.0170), and long intensive care unit (ICU) stays (P=0.0263) were associated with lower odds of non-compliance. It also showed a significant interaction between ACS history and age (P=0.0131), such that young patients with their first ACS showed significantly lower odds of CPAP non-compliance than patients with recurrent ACS and significantly lower odds of CPAP non-compliance were associated with ageing only in patients with recurrent ACS.

Conclusions

Protective factors against non-compliance with CPAP treatment in non-sleepy patients with ACS were illness severity (high values of AHI or ICU stay length) or smoking amount. Patients with no previous history of ACS showed lower odds of CPAP non-compliance than patients with a recurrent ACS with younger age.

Sex Differences in the Prevalence and Modulators of Sleep-Disordered Breathing in Outpatients with Type 2 Diabetes

In patients with type 2 diabetes, sleep-disordered breathing is a widespread cause of deteriorated quality of life. However, robust prevalence estimates for sleep-disordered breathing in patients with type 2 diabetes are limited due to scarce data. We investigated sex differences in sleep-disordered breathing prevalence and its modulators in the DIACORE SDB substudy, a sample of outpatient type 2 diabetes. 721 participants were tested for sleep-disordered breathing using a two-channel sleep apnoea monitoring device. Patients were stratified according to the severity of sleep-disordered breathing, defined as an apnoea-hypopnoea index < 15, ≥15 to 29, and ≥30 events per hour as no/mild, moderate, and severe sleep-disordered breathing, respectively. In the 679 analysed patients (39% women, age 66 ± 9 years, body mass index 31.0 ± 5.4 kg/m²), the prevalence of sleep-disordered breathing was 34%. The prevalence of sleep-disordered breathing was higher in men than in women (41% versus 22%, p < 0.001) and increased with age (15%, 21%, and 30% in women and 35%, 40%, and 47% in men in those aged 18-59, 60-69, or ≥70, respectively; age trend p = 0.064 in women and p = 0.15 in men). In linear regression analysis, age, BMI, and waist-hip ratio were associated with apnoea-hypopnoea index. Modulators for higher apnoea-hypopnoea index seem to be similar in men and women.

Which place of pharmacological approaches beyond continuous positive airway pressure to treat vascular disease related to obstructive sleep apnea?

Obstructive sleep apnea (OSA) is characterized by recurrent episodes of partial or complete upper airway obstruction, occurring during sleep, leading to chronic intermittent hypoxia (IH), which harms the cardiovascular system. OSA is associated with both functional and structural vascular alterations that contribute to an increased prevalence of fatal and non-fatal cardiovascular events. OSA is a heterogeneous disease with respect to the severity of hypoxia, the presence of daytime symptoms, obesity, and cardiovascular comorbidities. Various clusters of OSA phenotypes have been described leading to more highly personalized treatment. The aim of this review is to describe the various therapeutic strategies including continuous positive airway pressure (CPAP), oral appliances, surgery, weight loss, and especially pharmacological interventions that have been evaluated to reduce vascular alterations in both OSA patients and preclinical animal models. Conventional therapies, predominantly CPAP, have a limited impact on vascular alterations in the presence of co-morbidities. A better knowledge of pharmacological therapies targeting IH-induced vascular alterations will facilitate the use of combined therapies and is crucial for designing clinical trials in well-defined OSA phenotypes.

Effects of a lifestyle intervention on REM sleep-related OSA severity in obese individuals with type 2 diabetes

The aim of this study was to determine if an intensive lifestyle intervention (ILI) reduces the severity of obstructive sleep apnea (OSA) in rapid-eye movement (REM) sleep, and to determine if longitudinal changes in glycaemic control are related to changes in OSA severity during REM sleep over a 4-year follow-up. This was a randomized controlled trial including 264 overweight/obese adults with type 2 diabetes (T2D) and OSA. Participants were randomized to an ILI targeted to weight loss or a diabetes support and education (DSE) control group. Measures included anthropometry, apnea-hypopnea index (AHI) during REM sleep (REM-AHI) and non-REM sleep (NREM-AHI) and glycated haemoglobin (HbA1c) at baseline and year 1, year 2 and year 4 follow-ups. Mean baseline values of REM-AHI were significantly higher than NREM-AHI in both groups. Both REM-AHI and NREM-AHI were reduced significantly more in ILI versus DSE, but these differences were attenuated slightly after adjustment for weight changes. Repeated-measure mixed-model analyses including data to year 4 demonstrated that changes in HbA1c were related significantly to changes in weight, but not to changes in REM-AHI and NREM-AHI. Compared to control, the ILI reduced REM-AHI and NREM-AHI during the 4-year follow-up. Weight, as opposed to REM-AHI and NREM-AHI, was related to changes in HbA1c. The findings imply that weight loss from a lifestyle intervention is more important than reductions in AHI for improving glycaemic control in T2D patients with OSA.

Upper airway surgery for obstructive sleep apnea reduces blood pressure

OBJECTIVES/HYPOTHESIS

To evaluate if upper airway surgery reduces blood pressure in patients with obstructive sleep apnea (OSA).

STUDY DESIGN

Prospective series.

METHODS

A prospective series of 112 consecutive OSA patients with hypertension (HTN). All patients were > 18 years old, respiratory disturbance index >5, all levels of apnea-hypopnea index (AHI), with a history of HTN treated with medication for at least 6 months. Surgical procedures included septoplasty, turbinate reduction, palate surgery, and tongue base reduction.

RESULTS

There were 92 men and 20 women, with a mean age of 48.6 years, mean body mass index (BMI) was 27.5 (range, 19.7-34.7). Mean follow-up was 16.1 months. The mean preoperative AHI was 32.6 (range, 1.2-104), with the mean lowest oxygen saturation (LSAT) of 79.9% (range, 52%-93%). The mean adjusted preoperative and postoperative systolic blood pressure (SBP) was reduced from 146 ± 15.3 mm Hg to 122 ± 12.5 mm Hg (P < .001), and diastolic blood pressure (DBP) was reduced from 91 ± 10.2 mm Hg to 76 ± 7.8 mm Hg (P < .001). There was a decrease in overall BMI from 27.5 ± 3.6 to 25.5 ± 3.0 (P < .001); however, based on multivariate analysis, the reduction in SBP and DBP was not affected by this BMI reduction. Fifty-eight patients (51.8%) did not require their antihypertensive after surgery. There was poor correlation noted between HTN with AHI, LSAT, and oxygen duration <90%.

CONCLUSIONS

Upper airway surgery does reduce SBP and DBP in patients with OSA.

LEVEL OF EVIDENCE

4. Laryngoscope, 128:523-527, 2018.

Association of Positive Airway Pressure With Cardiovascular Events and Death in Adults With Sleep Apnea: A Systematic Review and Meta-analysis

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.