The hypoxic burden of sleep apnoea predicts cardiovascular disease-related mortality: the Osteoporotic Fractures in Men Study and the Sleep Heart Health Study

A new perspective on OSAS cases with the baveno classification

OBJECTIVE/BACKGROUND

Since the apnea-hypopnea index (AHI), which is used in the diagnosis and grading of OSAS, does not adequately reflect the clinical perspective of the disease, the Baveno classification of OSA was developed, which allows multicomponent evaluation of OSAS patients. The aim of our study was to evaluate the application of the Baveno classification in clinical practice.

PATIENTS/METHODS

A prospective study was performed on patients diagnosed with OSAS between January 2021 and June 2022. Patients were divided into 4 groups according to Baveno classification (Groups A-D) and three groups as mild, moderate, and severe OSAS according to AHI.

RESULTS

A total of 378 patients (70% male, mean age 48.68 ± 11.81 years) were included in the study. The patients had mild (n: 75; 20%), moderate (n:88; 23%), and severe (n:215; 57%) OSAS. According to Baveno classification, patients were included in Groups A (n:90; 24%), B (n: 105 (28%), C (n:65; 17%), and D (n:118;3 1%). The mean AHIs of the Baveno groups were similar (p = 0.116). Oxygen desaturation index (ODI) was higher in Groups B and D compared to Group A. The duration of T90 desaturation was longer in Groups C and D compared to Groups A and B (p < 0.05).

CONCLUSIONS

The Baveno classification divided our OSAS cases into equivalent groups. One out of every four patients with mild OSAS was in Group D. This data was noteworthy in that the Baveno classification allows for the identification of symptomatic and comorbid patients with mild OSAS according to AHI and for the application of more effective treatments to these patients. Patients with comorbidities experienced oxygen desaturation for a longer period of time at night, and oxygenation deteriorated in patients with prominent symptoms. Baveno classification was found to be a more reasonable and easily applicable approach in clinical practice.

Measures of overnight oxygen saturation to characterize sleep apnea severity and predict postoperative respiratory depression

BACKGROUND

Sleep apnea syndrome, characterized by recurrent cessation (apnea) or reduction (hypopnea) of breathing during sleep, is a major risk factor for postoperative respiratory depression. Challenges in sleep apnea assessment have led to the proposal of alternative metrics derived from oxyhemoglobin saturation (SpO2), such as oxygen desaturation index (ODI) and percentage of cumulative sleep time spent with SpO2 below 90% (CT90), as predictors of postoperative respiratory depression. However, their performance has been limited with area under the curve of 0.60 for ODI and 0.59 for CT90. Our objective was to propose novel features from preoperative overnight SpO2 which are correlated with sleep apnea severity and predictive of postoperative respiratory depression.

METHODS

Preoperative SpO2 signals from 235 surgical patients were retrospectively analyzed to derive seven features to characterize the sleep apnea severity. The features included entropy and standard deviation of SpO2 signal; below average burden characterizing the area under the average SpO2; average, standard deviation, and entropy of desaturation burdens; and overall nocturnal desaturation burden. The association between the extracted features and sleep apnea severity was assessed using Pearson correlation analysis. Logistic regression was employed to evaluate the predictive performance of the features in identifying postoperative respiratory depression.

RESULTS

Our findings indicated a similar performance of the proposed features to the conventional apnea-hypopnea index (AHI) for assessing sleep apnea severity, with average area under the curve ranging from 0.77 to 0.81. Notably, entropy and standard deviation of overnight SpO2 signal and below average burden showed comparable predictive capability to AHI but with minimal computational requirements and individuals' burden, making them promising for screening purposes. Our sex-based analysis revealed that compared to entropy and standard deviation, below average burden exhibited higher sensitivity in detecting respiratory depression in women than men.

CONCLUSION

This study underscores the potential of preoperative SpO2 features as alternative metrics to AHI in predicting postoperative respiratory.

Nocturnal Hypoxemic Burden in Patients with Heart Failure: Emerging Prognostic Role of Its Non-Specific Component

BACKGROUND

Nocturnal hypoxemic burden has been shown to be a robust, independent predictor of all-cause mortality in patients with heart failure and reduced ejection fraction (HFrEF) and to occur in a severe form even in patients with low or negligible frequency of respiratory events (apneas/hypopneas). This suggests the existence of two components of hypoxemic burden: one unrelated to respiratory events and the other related. The aim of this study was to characterize these two components and to evaluate their prognostic value.

METHODS

Nocturnal hypoxemic burden was assessed in a cohort of 280 patients with HFrEF by measuring the percentage of sleep with an oxygen saturation (SpO2) <90% (T90), and the area of the SpO2 curve below 90% (Area90). Both indices were also recalculated within the sleep segments associated with respiratory events (event-related component: T90Eve, Area90Eve) and outside these segments (non-specific component: T90Nspec, Area90Nspec). The outcome of the survival analysis (Cox regression) was all-cause mortality.

RESULTS

During a median follow-up of 60 months, 87 patients died. T90, Area90, and their components were significant in univariate analysis (p<0.05 all). However, when these indices were adjusted for known risk factors, T90, T90Nspec, Area90, and Area90Nspec remained statistically significant (p=0.018, hazard ratio (HR)=1.12, 95%CI=(1.02, 1.23); p=0.007, HR=1.20, 95%CI=(1.05, 1.37); p=0.020, HR=1.05, 95%CI=(1.01, 1.10); p=0.0006, HR=1.15, 95%CI=(1.06, 1.25)), whereas T90Eve and Area90Eve did not (p=0.27, p=0.28). These results were internally validated using bootstrap resampling.

CONCLUSIONS

By demonstrating a significant independent association of non-specific hypoxemic burden with all-cause mortality, this study suggests that this component of total nocturnal hypoxemic burden may play an important prognostic role in patients with HFrEF.

Sleep disordered breathing: OSA-COPD overlap

INTRODUCTION

Sleep has important effects on breathing and gas exchange that may have negative consequences in patients with chronic obstructive pulmonary disease (COPD). COPD and obstructive sleep apnea (OSA) are highly prevalent and may coexist, which is referred to as the overlap syndrome.

AREAS COVERED

The probability of OSA-COPD overlap represents the balance of protective and promoting factors such as hyperinflation and fluid retention; thus, different clinical COPD phenotypes influence the likelihood of comorbid OSA. The clinical presentation of OSA-COPD overlap is nonspecific, and the diagnosis requires clinical awareness to identify patients needing overnight studies. Both COPD and OSA are associated with a range of overlapping physiological and biological disturbances including hypoxia and inflammation that contribute to cardiovascular comorbidities. The management of OSA-COPD overlap patients differs from those with COPD alone and the survival of overlap patients treated with positive airway pressure (PAP) is superior to those untreated.

EXPERT OPINION

The recognition of OSA-COPD overlap has important clinical relevance because of its impact on outcomes and management. Management of the overlap should address both sleep quality and disordered gas exchange. PAP therapy has demonstrated reductions in COPD exacerbations, hospitalizations, healthcare costs and mortality in overlap patients.

Multi-center safety and efficacy study of a negative-pressure intraoral device in obstructive sleep apnea

BACKGROUND

Intraoral devices, with or without negative oral pressure, can stabilize the oropharynx and reduce obstructive sleep apneas. We tested the hypothesis that treatment with the iNAP® Sleep Therapy System, which applies negative oral pressure through an intra-oral appliance, would reduce the severity of obstructive sleep apnea in a multi-center, prospective, first-night-randomized-order cross-over study.

METHODS/PATIENTS

130 patients fulfilled the entry criteria (age <75, AHI 15-55, BMI <33), and 63 entered the primary endpoint cohort (Total Sleep Time ≥4 h/night on the baseline polysomnogram and an oral negative vacuum time maintained by iNAP® ≥ 4 h/night and total sleep time ≥4 h/night during the first treatment study). 54 patients completed a second treatment sleep study at least 28 days after the first sleep study.

RESULTS

Among the primary endpoint cohort (n = 63, age = 53.2 ± 11.3, BMI = 27.1 ± 2.8), 33 patients (52 %; 95 % confidence interval = 40%-64 %, p < 0.001) responded to iNAP treatment according to the Sher criteria (>50 % reduction in AHI and an AHI ≤20 events/hr). The average oxy-hemoglobin saturation increased by 1-2%, and the average percent oxygen desaturation decreased (was less severe) by 1 % while using the iNAP device. The incidence of adverse events, all self-limited, was low. The reduction in the apnea-hypopnea index was durable over the 28-day study. Patients used iNAP on average 5.6 h per night during the study period.

CONCLUSION

The iNAP® Sleep Therapy System achieved a durable benefit in more than half the patients with moderate to severe obstructive sleep apnea and may be considered in patients who object to or failed continuous positive airway pressure.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02698059.

Influence of Impaired Diffusing Capacity and Sleep-disordered Breathing on Nocturnal Hypoxemia and Health Outcomes in Men with and without Human Immunodeficiency Virus

Rationale: Nocturnal hypoxemia is common in sleep-disordered breathing (SDB) and is associated with increased morbidity and mortality. Although impaired diffusing capacity of the lung for carbon monoxide (DlCO) is associated with daytime hypoxemia, its influence on SDB-related nocturnal hypoxemia is not known. Objectives: To characterize the effects of DlCO impairment on SDB-related nocturnal hypoxemia and associated health outcomes. Methods: Data from a multicenter cohort of men with and without human immunodeficiency virus (HIV) infection, with concomitant measures of DlCO and home-based polysomnography (n = 544), were analyzed. Multivariable quantile regression models characterized associations between DlCO and several measures of SDB-related hypoxemia (e.g., total sleep time with oxygen saturation as measured by pulse oximetry [SpO2] < 90% [T90]). Structural equation models were used to assess associations of impaired DlCO and SDB-related hypoxemia measures with prevalent hypertension and type 2 diabetes. Results: DlCO impairment (<80% predicted) was associated with sleep-related hypoxemia. Participants with severe SDB (apnea-hypopnea index ⩾ 30 events/h) and impaired DlCO had higher T90 (median difference, 15.0% [95% confidence interval (CI), 10.3% to 19.7%]) and average SDB-related desaturation (median difference, 1.0 [95% CI, 0.5 to 1.5]) and lower nadir SpO2 (median difference, -8.2% [95% CI, -11.4% to -4.9%]) and average SpO2 during sleep (median difference, -1.1% [95% CI, -2.1% to -0.01%]) than those with severe SDB and preserved DlCO. Higher T90 was associated with higher adjusted odds of prevalent hypertension (odds ratio, 1.39 [95% CI, 1.14 to 1.70]) and type 2 diabetes (odds ratio, 1.25 [95% CI, 1.07 to 1.46]). Conclusions: DlCO impairment in severe SDB was associated with sleep-related hypoxemia, prevalent hypertension, and type 2 diabetes. Assessment of SDB should be considered in those with impaired DlCO to guide testing and risk stratification strategies.

Long-term incident severe outcomes in a prospective cohort of non-obese obstructive sleep apnoea patients free of comorbidities at inclusion

In a prospective cohort of OSA patients without comorbidities at inclusion, age, mean blood pressure, mean oxygen saturation and minimum oxygen saturation were associated with long-term incidence of severe health events https://bit.ly/3VyYEzC.

Sleep apnea-related hypoxic burden as a predictor of pregnancy and neonatal outcome

STUDY OBJECTIVES

To determine the clinical impact of sleep apnea-related hypoxic burden in pregnant women and neonates.

METHODS

This is a secondary analysis of the Nulliparous Pregnancy Outcomes Study: Monitoring Mothers-to-Be (nuMoM2b) study. Hypoxia burden was calculated from the home sleep apnea test (HSAT) and defined as the total area under respiratory events. Logistic regression analysis assessed the relationship between hypoxia burden and pregnancy/neonatal outcomes.

RESULTS

A total of 3006 subjects in the early term, and 2326 subjects in the middle term of pregnancy, had HSAT. A hypoxic burden greater than 6.8%min was present in 1740 at early term and associated with a higher risk of preeclampsia (odds ratio 1.297, 95 % confidence interval 1.032-1.630, p: 0.026) after adjusted by obstructive sleep apnea (OSA) severity. In the middle term, 1058 subjects had a hypoxia burden more than 11.8%min, which was a predictor for higher incidence of gestational diabetes (OR 1.795, 95 % CI 1.097-2.938, p: 0.020) and an Apgar <7 at 1 min (OR 1.446, 95 % CI 1.079-1.939, p: 0.012) after adjusted by obstructive sleep apnea (OSA) severity. After adjusted by oxygenation disturbance index, HB was not related with Apgar <7 at 1 min (p:0.565).

CONCLUSIONS

The hypoxic burden is an independent predictor for preeclampsia and gestational diabetes and an Apgar <7 at 1 min.

Obstructive Sleep Apnea and Oxygenation in Very Old Adults: A Propensity-Score Match Study

OBJECTIVES

The prevalence of obstructive sleep apnea (OSA) escalates with advancing age. Although the apnea-hypopnea index (AHI) is the standard measure for assessing OSA severity, it does not account for additional oximetric parameters that may influence disease progression in older adults. This study aimed to evaluate disparities in respiratory polygraphy/polysomnography parameters among patients with OSA, stratified by age and sex.

DESIGN

Retrospective propensity score-matched study.

SETTING AND PARTICIPANTS

Sleep unit of a university hospital; 11,747 participants, 210 aged 80 years or older.

METHODS

Propensity score matching was used to establish 4 age cohorts, with the 210 oldest adults serving as the reference group. Primary outcome variables included the total sleep time with oxygen saturation (SaO2) below 90% (T90), average SaO2, minimum SaO2, and AHI. The association between T90 and AHI, as well as the severity of OSA, was assessed across the 4 age categories.

RESULTS

Despite comparable AHI scores, the oldest patients with OSA exhibited the highest T90 and the lowest SaO2 levels compared to younger counterparts. The proportion of patients with severe OSA and T90 in the highest quartile increased with age: 12.5% in young adults, 14.8% in adults, 21.7% in the old, and 34% in the very old participants (P < .001). old and very old patients had a greater likelihood of being in the most severe OSA category compared to the younger ones, with odds ratios (OR) 2.57 (95% CI 1.42-4.65) and 5.52 (95% CI 3.06-9.97), respectively. These patterns were more pronounced in women of advanced age, indicating a sex-specific variation in disease severity with increasing age.

CONCLUSIONS AND IMPLICATIONS

Old patients with OSA, particularly women, demonstrate elevated T90 and reduced SaO2 levels, irrespective of AHI, indicating a hypoxemia increased risk. The diagnostic criteria, management, and outcomes for OSA may require adaptations to address the unique needs of very old populations.

Heterogeneous Effects of Continuous Positive Airway Pressure in Non-Sleepy Obstructive Sleep Apnea on Cardiovascular Disease Outcomes: Post Hoc Machine Learning Analysis of the ISAACC Trial (ECSACT Study)

Rationale: Randomized controlled trials of continuous positive airway pressure (CPAP) therapy for cardiovascular disease (CVD) prevention among patients with obstructive sleep apnea (OSA) have been largely neutral. However, given that OSA is a heterogeneous disease, there may be unidentified subgroups demonstrating differential treatment effects. Objectives: We sought to apply a novel data-drive approach to identify nonsleepy OSA subgroups with heterogeneous effects of CPAP on CVD outcomes within the Impact of Sleep Apnea Syndrome in the Evolution of Acute Coronary Syndrome (ISAACC) study. Methods: Participants were randomly partitioned into two datasets. One for training (70%) our machine-learning model and a second (30%) for validation of significant findings. Model-based recursive partitioning was applied to identify subgroups with heterogeneous treatment effects. Survival analysis was conducted to compare treatment (CPAP vs. usual care [UC]) outcomes within subgroups. Results: A total of 1,224 nonsleepy OSA participants were included. Of 55 features entered into our model, only two appeared in the final model (i.e., average OSA event duration and hypercholesterolemia). Among participants at or below the model-derived average event duration threshold (19.5 s), CPAP was protective for a composite of CVD events (training hazard ratio [HR], 0.46; P = 0.002). For those with longer event duration (>19.5 s), an additional split occurred by hypercholesterolemia status. Among participants with longer event duration and hypercholesterolemia, CPAP resulted in more CVD events compared with UC (training HR, 2.24; P = 0.011). The point estimate for this harmful signal was also replicated in the testing dataset (HR, 1.83; P = 0.118). Conclusions: We discovered subgroups of nonsleepy OSA participants within the ISAACC study with heterogeneous effects of CPAP. Among the training dataset, those with longer OSA event duration and hypercholesterolemia had nearly 2.5 times more CVD events with CPAP compared with UC, whereas those with shorter OSA event duration had roughly half the rate of CVD events if randomized to CPAP.

Association between multiple sleep dimensions in obstructive sleep apnea and an early sign of atherosclerosis

STUDY OBJECTIVES

We investigated the associations between multiple sleep dimensions in obstructive sleep apnea (OSA) and carotid intima-media thickness (CIMT), an early sign of atherosclerosis, in participants from the Shanghai Sleep Health Study.

METHODS

We performed secondary analysis of SSHS in a group of subjects who underwent ultrasound evaluation from 2018 to 2022. Multiple sleep dimensions were measured using standard polysomnography. CIMT was measured from ultrasound images as an early sign of atherosclerosis. Multivariable-adjusted linear regression and logistic regression analyses were performed to detect associations between sleep traits in OSA and CIMT.

RESULTS

CIMT was found to increase with increasing severity of OSA (P < .001). When adjusted for conventional risk factors, microarousal index and hypoxic burden were positively correlated with CIMT, while slow-wave sleep and mean apnea-hypopnea event duration showed a negative correlation with CIMT (all P < .01). In binary logistic regression analysis, participants with a high microarousal index, less slow-wave sleep, higher hypoxic burden, and shorter mean apnea-hypopnea event duration showed a higher prevalence of thick CIMT with no evidence of interaction by age, sex, or body mass index (P-interaction > .05).

CONCLUSIONS

Patients with more severe sleep fragmentation, more severe hypoxemia, and increased arousability were more likely to have increased CIMT after adjusting for potential confounders. It is important to evaluate novel indices of sleep fragmentation, hypoxemia, and arousability in OSA for early detection and prevention of cardiovascular disease, including stroke.

CLINICAL TRIAL REGISTRATION

Registry: Chinese Clinical Trial Registry; Name: Establishing Bio-bank and Cohort of OSAHS in Hospital-based Population; URL: http://www.chictr.org.cn/showproj.aspx?proj=43057; Identifier: ChiCTR1900025714.

CITATION

Huang W, Zhou E, Zhang J, et al. Association between multiple sleep dimensions in obstructive sleep apnea and an early sign of atherosclerosis. J Clin Sleep Med. 2024;20(7):1093-1104.

Tirzepatide for the Treatment of Obstructive Sleep Apnea and Obesity

BACKGROUND

Obstructive sleep apnea is characterized by disordered breathing during sleep and is associated with major cardiovascular complications; excess adiposity is an etiologic risk factor. Tirzepatide may be a potential treatment.

METHODS

We conducted two phase 3, double-blind, randomized, controlled trials involving adults with moderate-to-severe obstructive sleep apnea and obesity. Participants who were not receiving treatment with positive airway pressure (PAP) at baseline were enrolled in trial 1, and those who were receiving PAP therapy at baseline were enrolled in trial 2. The participants were assigned in a 1:1 ratio to receive either the maximum tolerated dose of tirzepatide (10 mg or 15 mg) or placebo for 52 weeks. The primary end point was the change in the apnea-hypopnea index (AHI, the number of apneas and hypopneas during an hour of sleep) from baseline. Key multiplicity-controlled secondary end points included the percent change in AHI and body weight and changes in hypoxic burden, patient-reported sleep impairment and disturbance, high-sensitivity C-reactive protein (hsCRP) concentration, and systolic blood pressure.

RESULTS

At baseline, the mean AHI was 51.5 events per hour in trial 1 and 49.5 events per hour in trial 2, and the mean body-mass index (BMI, the weight in kilograms divided by the square of the height in meters) was 39.1 and 38.7, respectively. In trial 1, the mean change in AHI at week 52 was -25.3 events per hour (95% confidence interval [CI], -29.3 to -21.2) with tirzepatide and -5.3 events per hour (95% CI, -9.4 to -1.1) with placebo, for an estimated treatment difference of -20.0 events per hour (95% CI, -25.8 to -14.2) (P<0.001). In trial 2, the mean change in AHI at week 52 was -29.3 events per hour (95% CI, -33.2 to -25.4) with tirzepatide and -5.5 events per hour (95% CI, -9.9 to -1.2) with placebo, for an estimated treatment difference of -23.8 events per hour (95% CI, -29.6 to -17.9) (P<0.001). Significant improvements in the measurements for all prespecified key secondary end points were observed with tirzepatide as compared with placebo. The most frequently reported adverse events with tirzepatide were gastrointestinal in nature and mostly mild to moderate in severity.

CONCLUSIONS

Among persons with moderate-to-severe obstructive sleep apnea and obesity, tirzepatide reduced the AHI, body weight, hypoxic burden, hsCRP concentration, and systolic blood pressure and improved sleep-related patient-reported outcomes. (Funded by Eli Lilly; SURMOUNT-OSA ClinicalTrials.gov number, NCT05412004.).

The relationship between haemoglobin concentrations and obstructive sleep apnea syndrome: A systematic review and meta-analysis

BACKGROUND

This systematic review and meta-analysis investigates the relationship between haemoglobin (Hb) concentrations and obstructive sleep apnea syndrome (OSAS).

METHODS

Following PRISMA guidelines, we searched PubMed, EMBASE, and Cochrane Library from inception to March 8, 2024. Eligible studies included cross-sectional, cohort, and case-control designs comparing Hb concentrations in OSAS patients and healthy controls. Two reviewers independently screened records and extracted data. The risk of bias was assessed using the Joanna Briggs Institute checklist.

RESULTS

A total of 27 studies involving 6499 OSAS subjects and 5199 controls were included. Hb concentrations were significantly higher in OSAS patients compared to controls (SMD: 0.28; 95 % CI: 0.18 to 0.39; I2 = 84.4 %). Subgroup analysis by OSAS severity showed that severe OSAS patients had higher Hb concentrations than those with mild/moderate OSAS. Sensitivity analyses confirmed the robustness of the findings. However, 7 studies reported opposite results, indicating possible regional or methodological differences.

CONCLUSION

Hb concentrations are elevated in OSAS patients, with higher levels observed in severe cases. The significant heterogeneity and the predominance of studies from Turkey highlight the need for further research in diverse populations. Limitations include potential publication bias and variability in study designs.

Physiological Consequences of Upper Airway Obstruction in Sleep Apnea

OSA is diagnosed and managed by a metric called the apnea-hypopnea index (AHI). The AHI quantifies the number of respiratory events (apnea or hypopnea), disregarding important information on the characteristics and physiological consequences of respiratory events, including degrees of ventilatory deficit and associated hypoxemia, cardiac autonomic response, and cortical activity. The oversimplification of the disorder by the AHI is considered one of the reasons for divergent findings on the associations of OSA and cardiovascular disease (CVD) in observational and randomized controlled trial studies. Prospective observational cohort studies have demonstrated strong associations of OSA with several cardiovascular diseases, and randomized controlled trials of CPAP intervention have not been able to detect a benefit of CPAP to reduce the risk of CVD. Over the last several years, novel methodologies have been proposed to better quantify the magnitude of OSA-related breathing disturbance and its physiological consequences. As a result, stronger associations with cardiovascular and neurocognitive outcomes have been observed. In this review, we focus on the methods that capture polysomnographic heterogeneity of OSA.

Intermittent Versus Sustained Hypoxemia from Sleep-disordered Breathing: Outcomes in Patients with Chronic Lung Disease and High Altitude

In a variety of physiologic and pathologic states, people may experience both chronic sustained hypoxemia and intermittent hypoxemia ("combined" or "overlap" hypoxemia). In general, hypoxemia in such instances predicts a variety of maladaptive outcomes, including excess cardiovascular disease or mortality. However, hypoxemia may be one of the myriad phenotypic effects in such states, making it difficult to ascertain whether adverse outcomes are primarily driven by hypoxemia, and if so, whether these effects are due to intermittent versus sustained hypoxemia.

Nocturnal oxygen resaturation parameters are associated with cardiorespiratory comorbidities

BACKGROUND

There are strong associations between oxygen desaturations and cardiovascular outcomes. Additionally, oxygen resaturation rates are linked to excessive daytime sleepiness independent of oxygen desaturation severity. No studies have yet looked at the independent effects of comorbidities or medications on resaturation parameters.

METHODS

The Sleep Heart Health Study data was utilised to derive oxygen saturation parameters from 5804 participants. Participants with a history of comorbidities or medication usage were compared against healthy participants with no comorbidity/medication history.

RESULTS

4293 participants (50.4% female, median age 64 years) were included in the analysis. Females recorded significantly faster resaturation rates (mean 0.61%/s) than males (mean 0.57%/s, p < 0.001), regardless of comorbidities. After adjusting for demographics, sleep parameters, and desaturation parameters, resaturation rate was reduced with hypertension (-0.09 (95% CI -0.16, -0.03)), myocardial infarction (-0.13 (95% CI -0.21, -0.04)) and heart failure (-0.19 (95% CI -0.33, -0.05)), or when using anti-hypertensives (-0.10 (95% CI -0.17, -0.03)), mental health medications (-0.18 (95% CI -0.27, -0.08)) or anticoagulants (-0.41 (95% CI -0.56, -0.26)). Desaturation to Resaturation ratio for duration was decreased with mental health (-0.21 (95% CI -0.34, -0.08)) or diabetic medications (-0.24 (95% CI -0.41, -0.07)), and desaturation to resaturation ratio for area decreased with heart failure (-0.25 (95% CI -0.42, -0.08)).

CONCLUSIONS

Comorbidities and medications significantly affect nocturnal resaturation parameters, independent of desaturation parameters. However, the causal relationship remains unclear. Further research can enhance our knowledge and develop more precise and safer interventions for individuals affected by certain comorbidities.

Long-term effects on clinical event, mental health, and related outcomes of CPAP for obstructive sleep apnea: a systematic review

STUDY OBJECTIVES

We performed a systematic review of long-term health outcomes of continuous positive airway pressure (CPAP) use in adults with obstructive sleep apnea.

METHODS

We updated prior systematic reviews with searches in multiple databases through January 3, 2023. We included randomized controlled trials (RCTs) and adjusted nonrandomized comparative studies that reported prespecified long-term (mostly > 1 year) health outcomes. We assessed risk of bias, conducted meta-analyses, and evaluated strength of evidence.

RESULTS

We found 38 eligible studies (16 trials, 22 observational). All conclusions were of low strength of evidence given study and data limitations. RCTs found no evidence of effect of CPAP on mortality (summary effect size [ES] 0.89; 95% confidence interval [CI] 0.66, 1.21); inclusion of adjusted nonrandomized comparative studies yields an association with reduced risk of death (ES 0.57; 95% CI 0.44, 0.73). RCTs found no evidence of effects of CPAP for cardiovascular death (ES 0.99; 95% CI 0.64, 1.53), stroke (ES 0.99; 95% CI 0.73, 1.35), myocardial infarction (ES 1.05; 95% CI 0.78, 1.41), incident atrial fibrillation (ES 0.89; 95% CI 0.48, 1.63), or composite cardiovascular outcomes (all statistically nonsignificant). RCTs found no evidence of effects for incident diabetes (ES 1.02; 95% CI 0.69, 1.51) or accidents (all nonsignificant) and no clinically significant effects on depressive symptoms, anxiety symptoms, or cognitive function.

CONCLUSIONS

Whether CPAP use for obstructive sleep apnea affects long-term health outcomes remains largely unanswered. RCTs and nonrandomized comparative studies are inconsistent regarding the effect of CPAP on mortality. Current studies are underpowered, with relatively short duration follow-up and methodological limitations.

CITATION

Balk EM, Adam GP, Cao W, Bhuma MR, D'Ambrosio C, Trikalinos TA. Long-term effects on clinical event, mental health, and related outcomes of CPAP for obstructive sleep apnea: a systematic review. J Clin Sleep Med. 2024;20(6):895-909.

Does Obstructive Sleep Apnea Lead to Progression of Chronic Obstructive Pulmonary Disease

Chronic obstructive pulmonary disease (COPD) and obstructive sleep apnea (OSA) have important bidirectional relationships that influence the pathophysiology of each disorder. The slim hyperinflated "pink puffer" phenotype of COPD protects against OSA, whereas the heavier "blue bloater" phenotype predisposes to OSA by fluid retention. OSA may aggravate COPD by promoting airway inflammation. COPD-OSA overlap patients have lower quality of life and are at higher risk of cardiovascular comorbidity than either disorder alone due to greater nocturnal oxygen desaturation and sympathetic activation. Management of OSA with positive airway pressure improves COPD outcomes that include lower exacerbation rates compared to untreated patients.

The PAP-RES algorithm: Defining who, why and how to use positive airway pressure therapy for OSA

Obstructive sleep apnea (OSA) is a common condition that is increasing in prevalence worldwide. Untreated OSA has a negative impact on health-related quality of life and is an independent risk factor for cardiovascular diseases. Despite available data suggesting that cardiovascular risk might differ according to clinical phenotypes and comorbidities, current approaches to OSA treatment usually take a "one size fits all" approach. Identification of cardiovascular vulnerability biomarkers and clinical phenotypes associated with response to positive airway pressure (PAP) therapy could help to redefine the standard treatment paradigm. The new PAP-RES (PAP-RESponsive) algorithm is based on the identification of OSA phenotypes that are likely to impact therapeutic goals and modalities. The paradigm shift is to propose a simplified approach that defines therapeutic goals based on OSA phenotype: from a predominantly "symptomatic phenotype" (individuals with high symptom burden that negatively impacts on daily life and/or accident risk or clinically significant insomnia) to a "vulnerable cardiovascular phenotype" (individuals with comorbidities [serious cardiovascular or respiratory disease or obesity] that have a negative impact on cardiovascular prognosis or a biomarker of hypoxic burden and/or autonomic nervous system dysfunction). Each phenotype requires a different PAP therapy care pathway based on differing health issues and treatment objectives.

Effect of obesity on sleep apnea pathogenesis differs in women versus men: multiple mediation analyses in the retrospective SNOOzzzE cohort

There are multiple mechanisms underlying obstructive sleep apnea (OSA) development. However, how classic OSA risk factors such as body mass index (BMI) and sex portend to OSA development has not been fully described. Thus we sought to evaluate how obesity leads to OSA and assess how these mechanisms differ between men and women. The San Diego Multi-Outcome OSA Endophenotype (SNOOzzzE) cohort includes 3,319 consecutive adults who underwent a clinical in-laboratory polysomnography at the University of California, San Diego, sleep clinic between January 2017 and December 2019. Using routine polysomnography signals, we determined OSA endotypes. We then performed mediation analyses stratified by sex to determine how BMI influenced the apnea-hypopnea index (AHI) using OSA pathophysiological traits as mediators, adjusting for age, race, and ethnicity. We included 2,146 patients of whom 919 (43%) were women and 1,227 (57%) were obese [body mass index (BMI) > 30 kg/m2]. BMI was significantly associated with AHI in both women and men. In men, the adjusted effect of BMI on AHI was partially mediated by a reduction in upper airway stiffness (βstandardized = 0.124), a reduction in circulatory delay (βstandardized = 0.063), and an increase in arousal threshold (βstandardized = 0.029; Pboot-strapped,all < 0.05). In women, the adjusted effect of BMI on AHI was partially mediated by a reduction in upper airway stiffness (βstandardized = 0.05) and circulatory delay (βstandardized = 0.037; Pboot-strapped,all < 0.05). BMI-related OSA pathogenesis differs by sex. An increase in upper airway collapsibility is consistent with prior studies. A reduction in circulatory delay may lead to shorter and thus more events per hour (higher AHI), while the relationship between arousal threshold and OSA is likely complex.NEW & NOTEWORTHY Our data provide important insights into obesity-related obstructive sleep apnea (OSA) pathogenesis, thereby validating, and extending, prior research findings. This is the largest sample size study to examine the relationships between obesity and gender on OSA pathogenesis. The influence of obesity on sleep apnea severity is mediated by different mechanistic traits (endotypes).

Tirzepatide for the treatment of obstructive sleep apnea: Rationale, design, and sample baseline characteristics of the SURMOUNT -OSA phase 3 trial

BACKGROUND

Weight reduction is a standard recommendation for obstructive sleep apnea (OSA) treatment in people with obesity or overweight; however, weight loss can be challenging to achieve and maintain without bariatric surgery. Currently, no approved anti-obesity medication has demonstrated effectiveness in OSA management. This study is evaluating the efficacy and safety of tirzepatide for treatment of moderate to severe OSA in people with obesity.

METHODS

SURMOUNT-OSA, a randomized, placebo -controlled, 52-week phase 3 trial, is investigating the efficacy and safety of tirzepatide for treatment of moderate to severe OSA (apnea hypopnea- index ≥15 events/h) in participants with obesity (body mass index ≥30 kg/m2) and an established OSA diagnosis. SURMOUNT-OSA is made of 2 intervention-specific appendices (ISAs): ISA-1 includes participants with no current OSA treatment, and ISA-2 includes participants using positive airway pressure therapy. Overall, 469 participants have been randomized 1:1 to receive tirzepatide or placebo across the master protocol (ISA-1, n = 234; ISA-2, n = 235). All participants are also receiving lifestyle intervention for weight reduction.

RESULTS

The primary endpoint for the individual ISAs is the difference in apnea hypopnea- index response, as measured by polysomnography, between tirzepatide and placebo arms at week 52. Secondary endpoints include sleep apnea-specific hypoxic burden, functional outcomes, and cardiometabolic biomarkers. The trial employs digital wearables, including home sleep testing to capture time to improvement and accelerometry for daily physical activity assessment, to evaluate exploratory outcomes.

CONCLUSION

SURMOUNT-OSA brings a novel design to investigate if tirzepatide provides clinically meaningful improvement in obesity-related OSA by targeting the underlying etiology.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT05412004.

Association between sleep apnea-specific hypoxic burden and severity of coronary artery disease

PURPOSE

Sleep apnea-specific hypoxic burden (SASHB) is a polysomnographic metric that comprehensively measures the degree of nocturnal desaturation caused by obstructive sleep apnea. This research was conducted to elucidate the relationship between SASHB and coronary artery disease (CAD) severity.

METHODS

We carried out a prospective study of hospitalized patients with CAD of unstable angina who were expected to undergo invasive coronary angiography at Beijing Anzhen Hospital from February to September 2023. SASHB values were calculated using a self-programmed C +  + program. Multivariable logistic regression analysis was applied to identify the association between SASHB and the prevalence of severe CAD, documented by the Gensini Score, and the SYNTAX (Synergy between Percutaneous Coronary Intervention With Taxus and Cardiac Surgery) Score.

RESULTS

This study enrolled 137 patients with a median age of 59 years, 96 (70.1%) of whom were male. A total of 125 (91.2%) patients had coronary stenosis of ≥ 50% in at least one location. Patients with a high SASHB of ≥ 18% min/h had a significantly higher Gensini Score (32.0 vs. 18.5, P = 0.002) and SYNTAX Score (14.0 vs. 7.0, P = 0.002) than those with a low SASHB. After adjusting for multiple covariates, a high SASHB was significantly associated with the prevalence of severe CAD, determined by a Gensini Score ≥ 21 (OR 2.67, P = 0.008) or a SYNTAX Score > 22 (OR 4.03, P = 0.016).

CONCLUSION

Our findings revealed a robust and independent association between SASHB and CAD severity in patients with unstable angina, highlighting the potential value of SASHB as a predictor of risk and a target for interventions aimed at preventing cardiovascular diseases.

TRIAL REGISTRATION

Chinese Clinical Trial Registry No. ChiCTR2300067991 on February 2, 2023.

The Association of High Arousal Threshold with Hypertension and Diabetes in Obstructive Sleep Apnea

Objective

Compared to low arousal threshold (AT), high AT is an easily overlooked characteristic for obstructive sleep apnea (OSA) severity estimation. This study aims to evaluate the relationship between high AT, hypertension and diabetes in OSA, compared to those with apnea-hypopnea index (AHI).

Methods

A total of 3400 adults diagnosed with OSA were retrospectively recruited. Propensity score matching (PSM) was conducted to further categorize these patients into the low and high AT groups based on the strategy established by previous literature. The different degrees of AHI and quantified AT (AT score) were subsequently measured. The correlation of AT and AHI with the occurrence of various comorbidities in OSA was estimated by logistic regression analysis with odds ratio (OR).

Results

After PSM, 938 pairs of patients arose. The median AT score of high and low AT group was 21.7 and 12.2 scores, and the adjusted OR of high AT for hypertension and diabetes was 1.31 (95% CI = 1.07-1.62, P < 0.01) and 1.45 (95% CI = 1.01-2.08, P < 0.05), respectively. Compared to low AT score group, the OR significantly increased in patients with very high AT score (30 ≤ AT score), especially for diabetes (OR = 1.79, 95% CI = 1.02-3.13, P < 0.05). The significant association was not observed in AHI with increasing prevalent diabetes.

Conclusion

Higher AT is significantly associated with increased prevalence of hypertension and diabetes in patients with OSA. Compared with AHI, AT score is a potentially comprehensive indicator for better evaluating the relationship between OSA and related comorbidities.

Hypoxic indices for obstructive sleep apnoea severity and cardiovascular disease risk prediction: A comparison and application in a community population

BACKGROUND AND OBJECTIVE

The apnoea-hypopnoea index (AHI) and oxygen desaturation index (ODI) encounter challenges in capturing the intricate relationship between obstructive sleep apnoea (OSA) and cardiovascular disease (CVD) risks. Although novel hypoxic indices have been proposed to tackle these limitations, there remains a gap in comprehensive validation and comparisons across a unified dataset.

METHODS

Samples were derived from the Sleep Heart Health Study (SHHS), involving 4485 participants aged over 40 years after data quality screening. The study compared several key indices, including AHI, ODI, the reconstructed hypoxic burden (rHB), the percentage of sleep time with the duration of respiratory events causing desaturation (pRED_3p) and the sleep breathing impairment index (SBII), in relation to CVD mortality and morbidity risks. Adjusted Cox proportional models were employed to calculate hazard ratios (HRs) for each index, and comparisons were performed.

RESULTS

SBII and pRED_3p exhibited significant correlations with both CVD mortality and morbidity, with SBII showing the highest adjusted HR (95% confidence interval) for mortality (2.04 [1.25, 3.34]) and pRED_3p for morbidity (1.43 [1.09-1.88]). In contrast, rHB was only significant in predicting CVD mortality (1.63 [1.05-2.53]), while AHI and ODI did not show significant correlations with CVD outcomes. The adjusted models based on SBII and pRED_3p exhibited optimal performance in the CVD mortality and morbidity datasets, respectively.

CONCLUSION

This study identified the optimal indices for OSA-related CVD risks prediction, SBII for mortality and pRED_3p for morbidity. The open-source online platform provides the computation of the indices.

Independent relationship between sleep apnea-specific hypoxic burden and glucolipid metabolism disorder: a cross-sectional study

OBJECTIVES

Obstructive sleep apnea (OSA) is associated with abnormal glucose and lipid metabolism. However, whether there is an independent association between Sleep Apnea-Specific Hypoxic Burden (SASHB) and glycolipid metabolism disorders in patients with OSA is unknown.

METHODS

We enrolled 2,173 participants with suspected OSA from January 2019 to July 2023 in this study. Polysomnographic variables, biochemical indicators, and physical measurements were collected from each participant. Multiple linear regression analyses were used to evaluate independent associations between SASHB, AHI, CT90 and glucose as well as lipid profile. Furthermore, logistic regressions were used to determine the odds ratios (ORs) for abnormal glucose and lipid metabolism across various SASHB, AHI, CT90 quartiles.

RESULTS

The SASHB was independently associated with fasting blood glucose (FBG) (β = 0.058, P = 0.016), fasting insulin (FIN) (β = 0.073, P < 0.001), homeostasis model assessment of insulin resistance (HOMA-IR) (β = 0.058, P = 0.011), total cholesterol (TC) (β = 0.100, P < 0.001), total triglycerides (TG) (β = 0.063, P = 0.011), low-density lipoprotein cholesterol (LDL-C) (β = 0.075, P = 0.003), apolipoprotein A-I (apoA-I) (β = 0.051, P = 0.049), apolipoprotein B (apoB) (β = 0.136, P < 0.001), apolipoprotein E (apoE) (β = 0.088, P < 0.001) after adjustments for confounding factors. Furthermore, the ORs for hyperinsulinemia across the higher SASHB quartiles were 1.527, 1.545, and 2.024 respectively, compared with the lowest quartile (P < 0.001 for a linear trend); the ORs for hyper-total cholesterolemia across the higher SASHB quartiles were 1.762, 1.998, and 2.708, compared with the lowest quartile (P < 0.001 for a linear trend) and the ORs for hyper-LDL cholesterolemia across the higher SASHB quartiles were 1.663, 1.695, and 2.316, compared with the lowest quartile (P < 0.001 for a linear trend). Notably, the ORs for hyper-triglyceridemia{1.471, 1.773, 2.099} and abnormal HOMA-IR{1.510, 1.492, 1.937} maintained a consistent trend across the SASHB quartiles.

CONCLUSIONS

We found SASHB was independently associated with hyperinsulinemia, abnormal HOMA-IR, hyper-total cholesterolemia, hyper-triglyceridemia and hyper-LDL cholesterolemia in Chinese Han population. Further prospective studies are needed to confirm that SASHB can be used as a predictor of abnormal glycolipid metabolism disorders in patients with OSA.

TRIAL REGISTRATION

ChiCTR1900025714 { http://www.chictr.org.cn/ }; Prospectively registered on 6 September 2019; China.

Reconsidering screening thresholds in health assessments for obstructive sleep apnea using operational and safety incident data

The rail industry in Australia screens workers for probable obstructive sleep apnea (OSA) due to known safety risks. However, existing criteria to trigger screening only identify a small proportion of workers with OSA. The current study sought to examine the relationship between OSA risk and rail incidents in real-world data from Australian train drivers, and conducted a proof of concept analysis to determine whether more conservative screening criteria are justified. Health assessment (2016-2018) and subsequent rail incident data (2016-2020) were collected from two passenger rail service providers. Predictors included OSA status (confirmed no OSA with a sleep study, controlled OSA, unknown OSA [no recorded sleep assessment data] and confirmed OSA with no indication of treatment); OSA risk according to the current Standard, and OSA risk according to more conservative clinical markers (BMI threshold and cardiometabolic burden). Coded rail safety incidents involving the train driver were included. Data were analysed using zero-inflated negative binomial models to account for over-dispersion with high 0 counts, and rail safety incidents are reported using Incidence Risk Ratios (IRRs). A total of 751 train drivers, typically middle-aged, overweight to obese and mostly men, were included in analyses. There were 43 (5.7%) drivers with confirmed OSA, 62 (8.2%) with controlled OSA, 13 (1.7%) with confirmed no OSA and 633 (84.4%) drivers with unknown OSA. Of the 633 train drivers with unknown OSA status, 21 (3.3%) met 'at risk' criteria for OSA according to the Standard, and incidents were 61% greater (IRR: 1.61, 95% Confidence Interval (CI) 1.02-2.56) in the years following their health assessment compared to drivers who did not meet 'at risk' criteria. A more conservative OSA risk status using lower BMI threshold and cardiometabolic burden identified an additional 30 'at risk' train drivers who had 46% greater incidents compared to drivers who did not meet risk criteria (IRR (95% CI) 1.46 (1.00-2.13)). Our more conservative OSA risk criteria identified more workers, with greater prospective incidents. These findings suggest that existing validated tools could be considered in future iterations of the Standard in order to more sensitively screen for OSA.

Treatment of Sleep Apnea and Reduction in Blood Pressure: The Role of Heart Rate Response and Hypoxic Burden

BACKGROUND

Obstructive sleep apnea is associated with increased blood pressure (BP). Obstructive sleep apnea treatment reduces BP with substantial variability, not explained by the apnea-hypopnea index, partly due to inadequate characterization of obstructive sleep apnea's physiological consequences, such as oxygen desaturation, cardiac autonomic response, and suboptimal treatment efficacy. We sought to examine whether a high baseline heart rate response (ΔHR), a marker of high cardiovascular risk in obstructive sleep apnea, predicts a larger reduction in post-treatment systolic BP (SBP). Furthermore, we aimed to assess the extent to which a reduction in SBP is explained by a treatment-related reduction in hypoxic burden (HB).

METHODS

ΔHR and HB were measured from pretreatment and posttreatment polygraphy, followed by a 24-hour BP assessment in 168 participants treated with continuous positive airway pressure or nocturnal supplemental oxygen from the HeartBEAT study (Heart Biomarker Evaluation in Apnea Treatment). Multiple linear regression models assessed whether high versus mid (reference) ΔHR predicted a larger reduction in SBP (primary outcome) and whether there was an association between treatment-related reductions in SBP and HB.

RESULTS

A high versus mid ΔHR predicted improvement in SBP (adjusted estimate, 5.8 [95% CI, 1.0-10.5] mm Hg). Independently, a greater treatment-related reduction in HB was significantly associated with larger reductions in SBP (4.2 [95% CI, 0.9-7.5] mm Hg per 2 SD treatment-related reduction in HB). Participants with substantial versus minimal treatment-related reductions in HB had a 6.5 (95% CI, 2.5-10.4) mm Hg drop in SBP.

CONCLUSIONS

A high ΔHR predicted a more favorable BP response to therapy. Furthermore, the magnitude of the reduction in BP was partly explained by a greater reduction in HB.

Predicting the impact of CPAP on brain health: A study using the sleep EEG-derived brain age index

OBJECTIVE

This longitudinal study investigated potential positive impact of CPAP treatment on brain health in individuals with obstructive sleep Apnea (OSA). To allow this, we aimed to employ sleep electroencephalogram (EEG)-derived brain age index (BAI) to quantify CPAP's impact on brain health and identify individually varying CPAP effects on brain aging using machine learning approaches.

METHODS

We retrospectively analyzed CPAP-treated (n = 98) and untreated OSA patients (n = 88) with a minimum 12-month follow-up of polysomnography. BAI was calculated by subtracting chronological age from the predicted brain age. To investigate BAI changes before and after CPAP treatment, we compared annual ΔBAI between CPAP-treated and untreated OSA patients. To identify individually varying CPAP effectiveness and factors influencing CPAP effectiveness, machine learning approaches were employed to predict which patient displayed positive outcomes (negative annual ΔBAI) based on their baseline clinical features.

RESULTS

CPAP-treated group showed lower annual ΔBAI than untreated (-0.6 ± 2.7 vs. 0.3 ± 2.6 years, p < 0.05). This BAI reduction with CPAP was reproduced independently in the Apnea, Bariatric surgery, and CPAP study cohort. Patients with more severe OSA at baseline displayed more positive annual ΔBAI (=accelerated brain aging) when untreated and displayed more negative annual ΔBAI (=decelerated brain aging) when CPAP-treated. Machine learning models achieved high accuracy (up to 86%) in predicting CPAP outcomes.

INTERPRETATION

CPAP treatment can alleviate brain aging in OSA, especially in severe cases. Sleep EEG-derived BAI has potential to assess CPAP's impact on brain health. The study provides insights into CPAP's effects and underscores BAI-based predictive modeling's utility in OSA management.

Associations of baseline obstructive sleep apnea and sleep macroarchitecture with cognitive function after 8 years in middle-aged and older men from a community-based cohort study

Previous prospective studies examining associations of obstructive sleep apnea and sleep macroarchitecture with future cognitive function recruited older participants, many demonstrating baseline cognitive impairment. This study examined obstructive sleep apnea and sleep macroarchitecture predictors of visual attention, processing speed, and executive function after 8 years among younger community-dwelling men. Florey Adelaide Male Ageing Study participants (n = 477) underwent home-based polysomnography, with 157 completing Trail-Making Tests A and B and the Mini-Mental State Examination. Associations of obstructive sleep apnea (apnea-hypopnea index, oxygen desaturation index, and hypoxic burden index) and sleep macroarchitecture (sleep stage percentages and total sleep time) parameters with future cognitive function were examined using regression models adjusted for baseline demographic, biomedical, and behavioural factors, and cognitive task performance. The mean (standard deviation) age of the men at baseline was 58.9 (8.9) years, with severe obstructive sleep apnea (apnea-hypopnea index ≥30 events/h) in 9.6%. The median (interquartile range) follow-up was 8.3 (7.9-8.6) years. A minority of men (14.6%) were cognitively impaired at baseline (Mini-Mental State Examination score <28/30). A higher percentage of light sleep was associated with better Trail-Making Test A performance (B = -0.04, 95% confidence interval [CI] -0.06, -0.01; p = 0.003), whereas higher mean oxygen saturation was associated with worse performance (B = 0.11, 95% CI 0.02, 0.19; p = 0.012). While obstructive sleep apnea and sleep macroarchitecture might predict cognitive decline, future studies should consider arousal events and non-routine hypoxaemia measures, which may show associations with cognitive decline.

Beat-to-beat cardiac repolarization lability increases during hypoxemia and arousals in obstructive sleep apnea patients

Obstructive sleep apnea (OSA) is associated with the progression of cardiovascular diseases, arrhythmias, and sudden cardiac death (SCD). However, the acute impacts of OSA and its consequences on heart function are not yet fully elucidated. We hypothesized that desaturation events acutely destabilize ventricular repolarization, and the presence of accompanying arousals magnifies this destabilization. Ventricular repolarization lability measures, comprising heart rate corrected QT (QTc), short-time-variability of QT (STVQT), and QT variability index (QTVI), were calculated before, during, and after 20,955 desaturations from lead II electrocardiography signals of 492 patients with suspected OSA (52% men). Variations in repolarization parameters were assessed during and after desaturations, both with and without accompanying arousals, and groupwise comparisons were performed based on desaturation duration and depth. Regression analyses were used to investigate the influence of confounding factors, comorbidities, and medications. The standard deviation (SD) of QT, mean QTc, SDQTc, and STVQT increased significantly (P < 0.01), whereas QTVI decreased (P < 0.01) during and after desaturations. The changes in SDQT, mean QTc, SDQTc, and QTVI were significantly amplified (P < 0.01) in the presence of accompanying arousals. Desaturation depth was an independent predictor of increased SDQTc (β = 0.405, P < 0.01), STVQT (β = 0.151, P < 0.01), and QTVI (β = 0.009, P < 0.01) during desaturation. Desaturations cause acute changes in ventricular repolarization, with deeper desaturations and accompanying arousals independently contributing to increased ventricular repolarization lability. This may partially explain the increased risk of arrhythmias and SCD in patients with OSA, especially when the OSA phenotype includes high hypoxic load and fragmented sleep.NEW & NOTEWORTHY Nocturnal desaturations are associated with increased ventricular repolarization lability. Deeper desaturations with accompanying arousals increase the magnitude of alterations, independent of confounding factors, comorbidities, and medications. Changes associated with desaturations can partially explain the increased risk of arrhythmias and sudden cardiac death in patients with OSA, especially in patients with high hypoxic load and fragmented sleep. This highlights the importance of detailed electrocardiogram analytics for patients with OSA.

The effect of pharyngeal structures on the severity of obstructive sleep apnea

BACKGROUND/OBJECTIVE

Obstructive sleep apnea (OSA) is characterized by complete or partial cessation of breathing during sleep. The tongue is suggested as a possible anatomical site causing airway obstruction. However, the role of other pharyngeal structures in the development of OSA remains unclear. We designed a study using both the apnea-hypopnea index (AHI) and the oxygen saturation measurements to assess the severity of OSA. We aimed to identify critical anatomical structures of the upper airway that correlate with the severity of OSA and to evaluate the utility of magnetic resonance imaging (MRI) markers to detect possible OSA in patients without overt symptoms.

MATERIALS AND METHODS

The study included participants referred to the neurology outpatient clinic from the check-up unit. Participants were grouped as controls, mild, moderate, or severe OSA according to the AHI. A cranial MRI with a field of view (FOV) encompassing the upper airway structures was obtained from all participants. The areas of the tongue and the uvula were measured on the sagittal images by drawing the boundaries of the tissues manually. The posterior air space (PAS) area was evaluated from regions of interest in five parallel planes.

RESULTS

Of 105 participants, 30 were controls, 27 had mild, 25 had moderate, and 23 had severe OSA. The moderate and severe OSA groups did not differ in oxygen saturation levels during sleep. Therefore, patients with moderate and severe OSA were combined into one group (moderate/severe OSA). The area of the tongue was significantly larger in the moderate/severe OSA group compared to the control group. Both the tongue and the uvula areas showed a significant positive correlation with the AHI.

CONCLUSION

Our findings suggest that the tongue and uvula have prominent roles in the severity of OSAS. It may be useful to measure these structures with MRI to screen for at-risk individuals without overt OSA symptoms.

Adherence to continuous positive airway pressure therapy in patients with spinal cord injury and obstructive sleep apnea: trajectories and predictors

PURPOSE

To identify specific determinants of non-adherence or cessation of continuous positive airway pressure (CPAP) therapy in a population of patients with spinal cord injuries (SCI).

METHODS

Retrospective analysis of data from patients with SCI who underwent a full night supervised polysomnography between 2015 and 2021 and presented with moderate to severe obstructive sleep apnea (OSA) and for whom CPAP was indicated. Adherence was studied at 1, 6, and 12 months. Univariate and multivariate analyses were performed to identify factors associated with non-adherence (< 4 h per night or CPAP cessation). Factors studied were demographic and disease-related data and both subjective and objective sleep parameters.

RESULTS

A total of 60 patients were included (40% cervical SCI). In univariate analysis, the only predictive parameters of non-adherence observed at 1, 6, and 12 months were the average use of CPAP on the 1st night (p = 0.02) and over the 1st week (p ≤ 0.001). A complete lesion (AIS-A) was predictive of non-adherence at 1 and 6 months (p = 0.02 at 6 months), while mask leakage was associated with non-adherence at 12 months (p = 0.02). Upper limb autonomy and the presence of family caregivers did not appear to be protective. In multivariate analysis, only the average use in the first week remained predictive of adherence (> 4 h) in the short, medium and long term.

CONCLUSION

In patients with SCI and OSA, the 1st week of CPAP treatment seems to be determinant of short-, medium-, and long-term CPAP adherence. Support for SCI patients from the start of treatment is essential and may help avoid treatment failures.

All Obstructive Sleep Apnea Events Are Not Created Equal: The Relationship between Event-related Hypoxemia and Physiologic Response

Rationale: Obstructive sleep apnea (OSA) severity is typically assessed by the apnea-hypopnea index (AHI), a frequency-based metric that allocates equal weight to all respiratory events. However, more severe events may have a greater physiologic impact. Objectives: The purpose of this study was to determine whether the degree of event-related hypoxemia would be associated with the postevent physiologic response. Methods: Patients with OSA (AHI, ⩾5/h) from the multicenter Canadian Sleep and Circadian Network cohort were studied. Using mixed-effect linear regression, we examined associations between event-related hypoxic burden (HBev) assessed by the area under the event-related oxygen saturation recording with heart rate changes (ΔHRev), vasoconstriction (vasoconstriction burden [VCBev] assessed with photoplethysmography), and electroencephalographic responses (power ratio before and after events). Results: Polysomnographic recordings from 658 patients (median [interquartile range] age, 55.00 [45.00, 64.00] yr; AHI, 27.15 [14.90, 64.05] events/h; 42% female) were included in the analyses. HBev was associated with an increase in all physiologic responses after controlling for age, sex, body mass index, sleep stage, total sleep time, and study centers; for example, 1 standard deviation increase in HBev was associated with 0.21 [95% confidence interval, 0.2, 0.22], 0.08 [0.08, 0.09], and 0.22 [0.21, 0.23] standard deviation increases in ΔHRev, VCBev, and β-power ratio, respectively. Conclusions: Increased event-related hypoxic burden was associated with greater responses across a broad range of physiologic signals. Future metrics that incorporate information about the variability of these physiologic responses may have promise in providing a more nuanced assessment of OSA severity.

Polysomnographic characteristics of excessive daytime sleepiness phenotypes in obstructive sleep apnea: results from the international sleep apnea global interdisciplinary consortium

STUDY OBJECTIVES

Excessive daytime sleepiness (EDS) is a major symptom of obstructive sleep apnea (OSA). Traditional polysomnographic (PSG) measures only partially explain EDS in OSA. This study analyzed traditional and novel PSG characteristics of two different measures of EDS among patients with OSA.

METHODS

Sleepiness was assessed using the Epworth Sleepiness Scale (>10 points defined as "risk of dozing") and a measure of general sleepiness (feeling sleepy ≥ 3 times/week defined as "feeling sleepy"). Four sleepiness phenotypes were identified: "non-sleepy," "risk of dozing only," "feeling sleepy only," and "both at risk of dozing and feeling sleepy."

RESULTS

Altogether, 2083 patients with OSA (69% male) with an apnea-hypopnea index (AHI) ≥ 5 events/hour were studied; 46% were "non-sleepy," 26% at "risk of dozing only," 7% were "feeling sleepy only," and 21% reported both. The two phenotypes at "risk of dozing" had higher AHI, more severe hypoxemia (as measured by oxygen desaturation index, minimum and average oxygen saturation [SpO2], time spent < 90% SpO2, and hypoxic impacts) and they spent less time awake, had shorter sleep latency, and higher heart rate response to arousals than "non-sleepy" and "feeling sleepy only" phenotypes. While statistically significant, effect sizes were small. Sleep stages, frequency of arousals, wake after sleep onset and limb movement did not differ between sleepiness phenotypes after adjusting for confounders.

CONCLUSIONS

In a large international group of patients with OSA, PSG characteristics were weakly associated with EDS. The physiological measures differed among individuals characterized as "risk of dozing" or "non-sleepy," while "feeling sleepy only" did not differ from "non-sleepy" individuals.

Associations between Nocturnal Hypoxemia and Retinal Nerve Fiber Layer Thinning: The Nagahama Study

Rationale: There have been meta-analyses that showed reduced retinal nerve fiber layer (RNFL) thickness, which is a surrogate marker of glaucoma, in patients with obstructive sleep apnea (OSA). However, the sample sizes in these reports were small (<300), and the mechanism of RNFL thinning in patients with OSA was not revealed.Objectives: To investigate the relationship of RNFL thickness with nocturnal hypoxemia or hypoxemic burden in a large-scale study.Methods: In this epidemiological study, 8,309 community residents were enrolled. The actigraphy-modified 3% oxygen desaturation index (acti-ODI3%) and cumulative percentage of sleep time with oxygen saturation <90% (acti-CT90) modified by objective sleep duration using actigraphy were measured. The hypoxemic burden is shown as acti-CT90. Circumpapillary RNFL thickness was determined using optical coherence tomography.Results: Multivariable logistic analysis models revealed that an increase in acti-CT90 was significantly associated with mean RNFL thinning after adjusting for several factors in participants without glaucoma diagnosed or treated previously (β = -0.037; P = 0.009). There were significant differences in mean RNFL thickness among participants stratified according to acti-CT90 (>1.5 vs. ⩽1.5; P = 0.04). Although acti-ODI3% was significantly associated with acti-CT90 (β = 0.72; P < 0.0001), acti-ODI3% was not significantly associated with mean RNFL thickness in the multivariable logistic analysis (β = -0.011; P = 0.48). In addition, acti-CT90 was significantly associated with mean RNFL thickness both in the elderly (⩾60 yr; β = -0.058; P = 0.002) and nonelderly (<60 yr; β = -0.054; P = 0.007).Conclusions: Acti-CT90, but not acti-ODI3%, was associated with mean RNFL thinning in participants irrespective of age in the elderly or nonelderly. Further prospective studies are required to investigate whether the prevention of hypoxic burden, which was shown as acti-CT90 in this study, is favorable for RNFL thinning.

Identifying clusters of patient comorbidities associated with obstructive sleep apnea using electronic health records

STUDY OBJECTIVES

The objectives of this study were to understand the relative comorbidity burden of obstructive sleep apnea (OSA), determine whether these relationships were modified by sex or age, and identify patient subtypes defined by common comorbidities.

METHODS

Cases with OSA and noncases (controls) were defined using a validated electronic health record (EHR)-based phenotype and matched for age, sex, and time period of follow-up in the EHR. We compared prevalence of the 20 most common comorbidities between matched cases and controls using conditional logistic regression with and without controlling for body mass index. Latent class analysis was used to identify subtypes of OSA cases defined by combinations of these comorbidities.

RESULTS

In total, 60,586 OSA cases were matched to 60,586 controls (from 1,226,755 total controls). Patients with OSA were more likely to have each of the 20 most common comorbidities compared with controls, with odds ratios ranging from 3.1 to 30.8 in the full matched set and 1.3 to 10.2 after body mass index adjustment. Associations between OSA and these comorbidities were generally stronger in females and patients with younger age at diagnosis. We identified 5 distinct subgroups based on EHR-defined comorbidities: High Comorbidity Burden, Low Comorbidity Burden, Cardiovascular Comorbidities, Inflammatory Conditions and Less Obesity, and Inflammatory Conditions and Obesity.

CONCLUSIONS

Our study demonstrates the power of leveraging the EHR to understand the relative health burden of OSA, as well as heterogeneity in these relationships based on age and sex. In addition to enrichment for comorbidities, we identified 5 novel OSA subtypes defined by combinations of comorbidities in the EHR, which may be informative for understanding disease outcomes and improving prevention and clinical care. Overall, this study adds more evidence that OSA is heterogeneous and requires personalized management.

CITATION

Te TT, Keenan BT, Veatch OJ, Boland MR, Hubbard RA, Pack AI. Identifying clusters of patient comorbidities associated with obstructive sleep apnea using electronic health records. J Clin Sleep Med. 2024;20(4):521-533.

Association of sleep timing with all-cause and cardiovascular mortality: the Sleep Heart Health Study and the Osteoporotic Fractures in Men Study

STUDY OBJECTIVES

Previous studies have highlighted the importance of sleep patterns for human health. This study aimed to investigate the association of sleep timing with all-cause and cardiovascular disease mortality.

METHODS

Participants were screened from two cohort studies: the Sleep Heart Health Study (SHHS; n = 4,824) and the Osteoporotic Fractures in Men Study (n = 2,658). Sleep timing, including bedtime and wake-up time, was obtained from sleep habit questionnaires at baseline. The sleep midpoint was defined as the halfway point between the bedtime and wake-up time. Restricted cubic splines and Cox proportional hazards regression analyses were used to examine the association between sleep timing and mortality.

RESULTS

We observed a U-shaped association between bedtime and all-cause mortality in both the SHHS and Osteoporotic Fractures in Men Study groups. Specifically, bedtime at 11:00 pm and waking up at 7:00 am was the nadir for all-cause and cardiovascular disease mortality risks. Individuals with late bedtime (> 12:00 am) had an increased risk of all-cause mortality in SHHS (hazard ratio 1.53, 95% confidence interval 1.28-1.84) and Osteoporotic Fractures in Men Study (hazard ratio 1.27, 95% confidence interval 1.01-1.58). In the SHHS, late wake-up time (> 8:00 am) was associated with increased all-cause mortality (hazard ratio 1.39, 95% confidence interval 1.13-1.72). No significant association was found between wake-up time and cardiovascular disease mortality. Delaying sleep midpoint (> 4:00 am) was also significantly associated with all-cause mortality in the SHHS and Osteoporotic Fractures in Men Study.

CONCLUSIONS

Sleep timing is associated with all-cause and cardiovascular disease mortality. Our findings highlight the importance of appropriate sleep timing in reducing mortality risk.

CITATION

Ma M, Fan Y, Peng Y, et al. Association of sleep timing with all-cause and cardiovascular mortality: the Sleep Heart Health Study and the Osteoporotic Fractures in Men Study. J Clin Sleep Med. 2024;20(4):545-553.

Diagnosis and management of obstructive sleep apnoea in adults

Obstructive sleep apnoea is the most common form of sleep-disordered breathing. It is characterised by recurrent occlusion of the airway during sleep. Ensuing apnoeas terminate in arousal from sleep and lead to non-restorative sleep, excessive daytime sleepiness and adverse cardiovascular and neurocognitive effects. A sleep study should be offered to patients reporting witnessed apnoeas or symptoms related to non-restorative sleep. It should also be considered in the presence of predisposing factors for obstructive sleep apnoea (e.g. obesity, tonsillar hypertrophy, retrognathia, refractory hypertension). Treatment should aim to improve symptoms and reduce cardiovascular and neurocognitive risk. The treatment approach should consider the symptom burden, severity, anatomical factors, and patient preference. Positive airway pressure is the most effective treatment option, although intolerance and non-adherence are common. Other options include positional therapy, oral appliances and upper airway surgery. Weight loss and optimisation of cardiovascular disease risk should be considered in selected patients.

A review of obstructive sleep apnea and lung cancer: epidemiology, pathogenesis, and therapeutic options

Despite undeniable advances in modern medicine, lung cancer still has high morbidity and mortality rates. Lung cancer is preventable and treatable, and it is important to identify new risk factors for lung cancer, especially those that can be treated or reversed. Obstructive sleep apnea (OSA) is a very common sleep-breathing disorder that is grossly underestimated in clinical practice. It can cause, exacerbate, and worsen adverse outcomes, including death and various diseases, but its relationship with lung cancer is unclear. A possible causal relationship between OSA and the onset and progression of lung cancer has been established biologically. The pathophysiological processes associated with OSA, such as sleep fragmentation, intermittent hypoxia, and increased sympathetic nervous excitation, may affect normal neuroendocrine regulation, impair immune function (especially innate and cellular immunity), and ultimately contribute to the occurrence of lung cancer, accelerate progression, and induce treatment resistance. OSA may be a contributor to but a preventable cause of the progression of lung cancer. However, whether this effect exists independently of other risk factors is unclear. Therefore, by reviewing the literature on the epidemiology, pathogenesis, and treatment of lung cancer and OSA, we hope to understand the relationships between the two and promote the interdisciplinary exchange of ideas between basic medicine, clinical medicine, respiratory medicine, sleep medicine, and oncology.

The Chinese Clinical Sleep Database: An Innovative Database System Includes Large-Scale Clinical Data of Chinese Population

Purpose

In this study, we established the Chinese Clinical Sleep Database (CCSD), aiming to provide a safe, scalable, and user-friendly database that includes high-quality clinical data from Chinese population to facilitate sleep research.

Material and Methods

We collect individual's demographic data, scales, anthropometric measurements, clinical diagnosis, and polysomnography (PSG) recordings from the routine medical process of sleep medicine centers using standardized procedures. The distributed cluster storage technology are utilized to store these data. The structured data are stored in a high-performance MySQL database, while the unstructured data are stored in an object storage service. And we have developed an online data platform to share and manage our data.

Results

The data collection has been conducted in three hospitals. In the preliminary stage of data collection (from October 18, 2022 to September 4, 2023), our database included a total of 1183 patients. Among them, 56.8% were male and their ages ranged from 3 to 88 years. These patients were diagnosed with various types of sleep disorders.

Conclusion

Since the CCSD's inception, it has demonstrated good stability, security, and scalability. As an public database, the CCSD also exhibits user-friendliness. The CCSD contains comprehensive clinical data, which can contribute to the advancement of the diagnosis and treatment strategies for sleep disorders, ultimately promoting sleep health.

Integrating Phenotypic Information of Obstructive Sleep Apnea and Deep Representation of Sleep-Event Sequences for Cardiovascular Risk Prediction

Background

Advances in mobile, wearable and machine learning (ML) technologies for gathering and analyzing long-term health data have opened up new possibilities for predicting and preventing cardiovascular diseases (CVDs). Meanwhile, the association between obstructive sleep apnea (OSA) and CV risk has been well-recognized. This study seeks to explore effective strategies of incorporating OSA phenotypic information and overnight physiological information for precise CV risk prediction in the general population.

Methods

1,874 participants without a history of CVDs from the MESA dataset were included for the 5-year CV risk prediction. Four OSA phenotypes were first identified by the K-mean clustering based on static polysomnographic (PSG) features. Then several phenotype-agnostic and phenotype-specific ML models, along with deep learning (DL) models that integrate deep representations of overnight sleep-event feature sequences, were built for CV risk prediction. Finally, feature importance analysis was conducted by calculating SHapley Additive exPlanations (SHAP) values for all features across the four phenotypes to provide model interpretability.

Results

All ML models showed improved performance after incorporating the OSA phenotypic information. The DL model trained with the proposed phenotype-contrastive training strategy performed the best, achieving an area under the Receiver Operating Characteristic (ROC) curve of 0.877. Moreover, PSG and FOOD FREQUENCY features were recognized as significant CV risk factors across all phenotypes, with each phenotype emphasizing unique features.

Conclusion

Models that are aware of OSA phenotypes are preferred, and lifestyle factors should be a greater focus for precise CV prevention and risk management in the general population.

ERS International Congress 2023: highlights from the Sleep Disordered Breathing Assembly

The topic of sleep-related breathing disorders is always evolving, and during the European Respiratory Society (ERS) International Congress 2023 in Milan, Italy, the latest research and clinical topics in respiratory medicine were presented. The most interesting issues included new diagnostic tools, such as cardiovascular parameters and artificial intelligence, pathophysiological traits of sleep disordered breathing from routine polysomnography or polygraphy signals, and new biomarkers and the diagnostic approach in patients with excessive daytime sleepiness. This article summarises the most relevant studies and topics presented at the ERS International Congress 2023. Each section has been written by early career members of ERS Assembly 4.

Impact of Comorbid Sleep-Disordered Breathing and Atrial Fibrillation on the Long-Term Outcome After Ischemic Stroke

BACKGROUND

Sleep-disordered breathing (SDB) and atrial fibrillation (AF) are highly prevalent in patients with stroke and are recognized as independent risk factors for stroke. Little is known about the impact of comorbid SDB and AF on long-term outcomes after stroke.

METHODS

In this prospective cohort study, 353 patients with acute ischemic stroke or transient ischemic attacks were analyzed. Patients were screened for SDB by respiratory polygraphy during acute hospitalization. Screening for AF was performed using a 7-day ECG up to 3× in the first 6 months. Follow-up visits were scheduled at 1, 3, 12, 24, and 36 months poststroke. Cox regression models adjusted for various factors (age, sex, body mass index, hypertension, diabetes, dyslipidemia, and heart failure) were used to assess the impact of comorbid SDB and AF on subsequent death or cerebro-cardiovascular events.

RESULTS

Among 353 patients (299 ischemic stroke and 54 transient ischemic attacks), median age, 67 (interquartile range, 57-74) years with 63% males. Moderate-to-severe SDB (apnea-hypopnea index score, ≥15/h) was present in 118 (33.4%) patients. Among the 56 (15.9%) patients with AF, 28 had comorbid moderate-to-severe SDB and AF. Over 36 months, there were 12 deaths and 67 recurrent cerebro-cardiovascular events. Patients with comorbid moderate-to-severe SDB and AF had a higher risk of subsequent death or cerebro-cardiovascular events compared with those with only moderate-to-severe SDB without AF (hazard ratio, 2.49 [95% CI, 1.18-5.24]) and to those without moderate-to-severe SDB or AF (hazard ratio, 2.25 [95% CI, 1.12-4.50]). However, no significant difference was found between the comorbid moderate-to-severe SDB and AF group and the group with only AF without moderate-to-severe SDB (hazard ratio, 1.64 [95% CI, 0.62-4.36]).

CONCLUSIONS

Comorbid moderate-to-severe SDB and AF significantly increase the risk of long-term mortality or recurrent cerebro-cardiovascular events after acute ischemic stroke. Considering both conditions as cumulative and modifiable cerebro-cardiovascular risk factors is of interest for the management of acute stroke.

REGISTRATION

URL: https://www.clinicaltrials.gov; Unique identifier: NCT02559739.

Is the time below 90% of SpO2 during sleep (T90%) a metric of good health? A longitudinal analysis of two cohorts

BACKGROUND

Novel wireless-based technologies can easily record pulse oximetry at home. One of the main parameters that are recorded in sleep studies is the time under 90% of SpO2 (T90%) and the oxygen desaturation index 3% (ODI-3%). We assessed the association of T90% and/or ODI-3% in two different scenarios (a community-based study and a clinical setting) with all-cause mortality (primary outcome).

METHODS

We included all individuals from the Sleep Heart Health Study (SHHS, community-based cohort) and Santiago Obstructive Sleep Apnea (SantOSA, clinical cohort) with complete data at baseline and follow-up. Two measures of hypoxemia (T90% and ODI-3%) were our primary exposures. The adjusted hazard ratios (HRs) per standard deviation (pSD) between T90% and incident all-cause mortality (primary outcome) were determined by adjusted Cox regression models. In the secondary analysis, to assess whether T90% varies across clinical factors, anthropometrics, abdominal obesity, metabolic rate, and SpO2, we conducted linear regression models. Incremental changes in R2 were conducted to test the hypothesis.

RESULTS

A total of 4323 (56% male, median 64 years old, follow-up: 12 years, 23% events) and 1345 (77% male, median 55 years old, follow-up: 6 years, 11.6% events) patients were included in SHHS and SantOSA, respectively. Every 1 SD increase in T90% was associated with an adjusted HR of 1.18 [95% CI: 1.10-1.26] (p value < 0.001) in SHHS and HR 1.34 [95% CI: 1.04-1.71] (p value = 0.021) for all-cause mortality in SantOSA. Conversely, ODI-3% was not associated with worse outcomes. R2 explains 62% of the variability in T90%. The main contributors were baseline-mean change in SpO2, baseline SpO2, respiratory events, and age.

CONCLUSION

The findings suggest that T90% may be an important marker of wellness in clinical and community-based scenarios. Although this nonspecific metric varies across the populations, ventilatory changes during sleep rather than other physiological or comorbidity variables explain their variability.

Metabolomic profiles of sleep-disordered breathing are associated with hypertension and diabetes mellitus development

Sleep-disordered breathing (SDB) is a prevalent disorder characterized by recurrent episodic upper airway obstruction. Using data from the Hispanic Community Health Study/Study of Latinos (HCHS/SOL), we apply principal component analysis (PCA) to seven SDB-related measures. We estimate the associations of the top two SDB PCs with serum levels of 617 metabolites, in both single-metabolite analysis, and a joint penalized regression analysis. The discovery analysis includes 3299 individuals, with validation in a separate dataset of 1522 individuals. Five metabolite associations with SDB PCs are discovered and replicated. SDB PC1, characterized by frequent respiratory events common in older and male adults, is associated with pregnanolone and progesterone-related sulfated metabolites. SDB PC2, characterized by short respiratory event length and self-reported restless sleep, enriched in young adults, is associated with sphingomyelins. Metabolite risk scores (MRSs), representing metabolite signatures associated with the two SDB PCs, are associated with 6-year incident hypertension and diabetes. These MRSs have the potential to serve as biomarkers for SDB, guiding risk stratification and treatment decisions.

Approach the Patient With Obstructive Sleep Apnea and Obesity

Obstructive sleep apnea (OSA) and obesity are highly prevalent and bidirectionally associated. OSA is underrecognized, however, particularly in women. By mechanisms that overlap with those of obesity, OSA increases the risk of developing, or having poor outcomes from, comorbid chronic disorders and impairs quality of life. Using 2 illustrative cases, we discuss the relationships between OSA and obesity with type 2 diabetes, dyslipidemia, cardiovascular disease, cognitive disturbance, mood disorders, lower urinary tract symptoms, sexual function, and reproductive disorders. The differences in OSA between men and women, the phenotypic variability of OSA, and comorbid sleep disorders are highlighted. When the probability of OSA is high due to consistent symptoms, comorbidities, or both, a diagnostic sleep study is advisable. Continuous positive airway pressure or mandibular advancement splints improve symptoms. Benefits for comorbidities are variable depending on nightly duration of use. By contrast, weight loss and optimization of lifestyle behaviors are consistently beneficial.

Positive Airway Pressure Therapy Predicts Lower Mortality and Major Adverse Cardiovascular Events Incidence in Medicare Beneficiaries with Obstructive Sleep Apnea

Background

Obesity is associated with obstructive sleep apnea (OSA) and cardiovascular risk. Positive airway pressure (PAP) is the first line treatment for OSA, but evidence on its beneficial effect on major adverse cardiovascular events (MACE) prevention is limited. Using claims data, the effects of PAP on mortality and incidence of MACE among Medicare beneficiaries with OSA were examined.

Methods

A cohort of Medicare beneficiaries with ≥2 distinct OSA claims was defined from multi-state, state-wide, multi-year (2011-2020) Medicare fee-for-service claims data. Evidence of PAP initiation and utilization was based on PAP claims after OSA diagnosis. MACE was defined as a composite of myocardial infarction, heart failure, stroke, or coronary revascularization. Doubly robust Cox proportional hazards models with inverse probability of treatment weights estimated treatment effects controlling for sociodemographic and clinical factors.

Results

Among 888,835 beneficiaries with OSA (median age 73 years; 43.9% women; median follow-up 1,141 days), those with evidence of PAP initiation (32.6%) had significantly lower all-cause mortality (HR [95%CI]: 0.53 [0.52-0.54]) and MACE incidence risk (0.90 [0.89-0.91]). Higher quartiles of annual PAP claims were progressively associated with lower mortality (Q2: 0.84 [0.81-0.87], Q3: 0.76 [0.74-0.79], Q4: 0.74 [0.72-0.77]) and MACE incidence risk (Q2: 0.92 [0.89-0.95], Q3: 0.89 [0.86-0.91], Q4: 0.87 [0.85-0.90]).

Conclusion

PAP utilization was associated with lower all-cause mortality and MACE incidence among Medicare beneficiaries with OSA. Results might inform trials assessing the importance of OSA therapy towards minimizing cardiovascular risk and mortality in older adults.