Obstructive sleep apnoea heterogeneity and cardiovascular disease.

From Resistant Airway to Resistant Hypertension.

Are we underestimating the lifelong benefits of therapy for obstructive sleep apnea? Alec M Berman, Saurabh S Thosar, Steven A SheaOregon Institute of Occupational Health Sciences, Oregon Health and Science University, Portland, OR, USAObstructive sleep apnea (OSA) is a complex disorder involving the cardiovascular (CV), pulmonary, and metabolic systems. Characterized by marked daytime fatigue and reduced quality of life, OSA is independently associated with increased risk of hypertension,1 cardiovascular disease (CVD),2 including myocardial infarction (MI)3 and ischemic stroke,4 metabolic syndrome,5 and all-cause mortality.6 Currently, the most common treatment for OSA is continuous positive airway pressure (CPAP) during sleep, though its efficacy in reducing daytime fatigue and CVD risk factors depends largely on compliance to therapy, which is poor in the general population.7 Lamberts et al8 performed a large epidemiological study of OSA, using the Danish National Patient Registry (NPR; ∼4.5 million; including 25,389 people diagnosed with OSA), which confirmed associations between OSA and risk of ischemic stroke and MI. Yet, that study failed to show that CPAP reduces the incidence of these adverse CV events.8 On the other hand, a more recent study, which examined the same Danish NPR across a very similar time period, revealed that in people with OSA, CPAP reduces all-cause mortality.9 This editorial evaluates these seemingly conflicting results, whereby CPAP appears to reduce mortality but not two of the largest contributors to mortality: stroke and MI.

Obstructive sleep apnea syndrome (OSAS) is associated with impairment of cognitive function, and improvement is often noted with treatment. Golf is a sport that requires a range of cognitive skills. We evaluated the impact of nasal positive airway pressure (PAP) therapy on the handicap index (HI) of golfers with OSAS. Golfers underwent a nocturnal polysomnogram (NPSG) to determine whether they had significant OSAS (respiratory disturbance index > 15). Twelve subjects with a positive NPSG were treated with PAP. HI, an Epworth Sleepiness Scale (ESS), and sleep questionnaire (SQ) were submitted upon study entry. After 20 rounds of golf on PAP treatment, the HI was recalculated, and the questionnaires were repeated. A matched control group composed of non-OSAS subjects was studied to assess the impact of the study construct on HI, ESS, and SQ. Statistical comparisons between pre- and post-PAP treatment were calculated. The control subjects demonstrated no significant change in HI, ESS, or SQ during this study, while the OSAS group demonstrated a significant drop in average HI (11.3%, p = 0.01), ESS, (p = 0.01), and SQ (p = 0.003). Among the more skilled golfers (defined as HI ≤ 12), the average HI dropped by an even greater degree (31.5%). Average utilization of PAP was 91.4% based on data card reporting. Treatment of OSAS with PAP enhanced performance in golfers with this condition. Treatment adherence was unusually high in this study. Non-medical performance improvement may be a strong motivator for selected subjects with OSAS to seek treatment and maximize adherence.

Metabolic Syndrome, Obstructive Sleep Apnea, and Continuous Positive Airway Pressure: A Weighty Issue

Background: Chronic obstructive pulmonary disease (COPD) and obstructive sleep apnea (OSA) are two of the most prevalent respiratory disorders in adults and are both independently associated with increased cardiovascular disease (CVD) risk. The coexistence of OSA in individuals with COPD is termed “overlap syndrome” and occurs in up to 65% of all COPD patients. Individuals with overlap syndrome have more frequent COPD exacerbations, poorer quality of life and increased CVD morbidity than patients with either COPD or OSA alone. COPD and OSA are both independently associated with increased carotid artery stiffness, a predictor of CVD events. However, the interaction of COPD and OSA on carotid artery stiffness remains unknown. We hypothesized that a) carotid artery stiffness would be greater in patients with overlap syndrome than COPD patients without OSA and non-COPD controls and b) overlap syndrome patients that reported using continuous positive airway pressure (CPAP) would have lower carotid artery stiffness than overlap patients not using a CPAP. Methods: Ninety-nine former smokers (n=62 with COPD and n=37 non-COPD controls; age 70 ± 7 yrs; 60M/39F) completed measurements of pulmonary function and common carotid artery stiffness and were retrospectively stratified by self-report of previous clinical diagnosis with OSA. Results: Participants with overlap syndrome had significantly greater carotid β-stiffness than COPD patients without OSA, non-COPD controls with OSA and non-COPD controls without OSA (overlap 5.7 ± 0.71 vs COPD only 3.9 ± 0.20, OSA only 3.6 ± 0.31, controls 3.7 ± 0.23 U; F=6.245, p<0.01) and this difference remained significant after adjustment for body mass index (p=0.01). There were no differences in blood pressure, heart rate, resting oxygen saturation (SpO 2 ) or nocturnal mean SpO 2 in those with overlap syndrome vs. the other groups. Furthermore, there was no difference in carotid β-stiffness between overlap syndrome patients that reported using vs. not using a CPAP (5.98 ± 0.7 vs 5.53 ± 1.9 U, p=0.80). Discussion: These data suggest that OSA exacerbates carotid artery stiffening in COPD patients and that carotid artery stiffness may be one mechanism that mediates the increased CVD risk observed in COPD patients with overlap syndrome.

Postoperative Complications in Patients With Obstructive Sleep Apnea Syndrome Undergoing Hip or Knee Replacement: A Case-Control Study

Introduction Obstructive sleep apnea (OSA) is a prevalent condition often managed with continuous positive airway pressure (CPAP) treatment. There is an ongoing debate about the link between OSA and cardiovascular disease (CVD), but the existing evidence points toward an association.Objective The present study aims to investigate whether CPAP is an effective strategy to reduce the risk of developing CVD risk among OSA patients.Methods The literature search was conducted in collaboration with Weill Cornell Medical College librarians, and we identified the five most recent papers highlighting the correlation between CPAP treatment for OSA and CVD risk reduction.Results Recent studies highlight the link between OSA and CVD, emphasizing the potential of the CPAP therapy to reduce the risks of developing CVD and the mortality associated with the condition. The analyses by Guo et al., Peker et al., Khan et al., and Wickwire et al., collectively involving thousands of patients across various study designs, including randomized clinical trials and retrospective cohort studies, consistently demonstrate that the CPAP treatment improves cardiovascular outcomes by lowering blood pressure, reducing sleepiness scores, and significantly decreasing the risk of serious CVD events, especially with consistent adherence to therapy.Conclusion Although further studies are needed to confirm these findings among patients with consistent high compliance to the CPAP treatment, it remains reasonable to continue to prescribe CPAP as the first-line therapy for OSA due to its potential cardiovascular benefits and low associated risks.

BackgroundThis retrospective cohort study aimed to determine if there are differences in cardiovascular co-morbidities, blood pressure (BP) and continuous positive airway pressure (CPAP) use between patients with positional-dependent and nonpositional-dependent obstructive sleep apnea (OSA).MethodsPatients who were referred for overnight polysomnography for suspected OSA between 2007 and 2011 were screened. A total of 371 patients with OSA were included for analysis and divided into six groups according to positional-dependency and severity of OSA: positional mild (n = 52), positional moderate (n = 29), positional severe (n = 24), non-positional mild (n = 18), non-positional moderate (n = 70) and non-positional severe group (n = 178). The six groups were compared for anthropometric and polysomnographic variables, presence of cardiovascular co-morbidities, morning and evening BP and the changes between evening and morning BP, and CPAP device usage patterns.ResultsDemographic and anthropometric variables showed non-positional severe OSA had poor sleep quality and higher morning blood pressures. Positional mild OSA had the lowest cardiovascular co-morbidities. Overall CPAP acceptance was 45.6%. Mild OSA patients had the lowest CPAP acceptance rate (10%), followed by moderate group (37.37%) and severe group (61.88%, P < 0.001). However, the significant difference in CPAP acceptance across OSA severity disappeared when the data was stratified by positional dependency.ConclusionsThis study found that positional mild OSA had less cardiovascular co-morbidities compared with subjects with positional severe OSA. Independent of posture, CPAP acceptance in patients with mild OSA was low, but CPAP compliance was similar in CPAP acceptors regardless of posture dependency of OSA. Since there are increasing evidences of greater cardiovascular risk for untreated mild OSA, improving CPAP acceptance among mild OSA patients may be clinically important regardless of posture dependency.

Obstructive sleep apnea (OSA) is an independent risk factor for cardiovascular disease (CVD). Although continuous positive airway pressure (CPAP) is the first-line treatment for OSA, its role in primary and secondary prevention of CVD remains controversial. This review explored the potential mechanisms, key evidence, and inconsistent outcomes of CPAP intervention in the context of OSA-related CVD. By incorporating insights into OSA subtypes, novel physiological markers, and practical clinical challenges, we revisited the indications for CPAP therapy. Ultimately, we emphasized the need to reassess CPAP indications based on individualized risk profiles to promote more precise and effective management of OSA-related cardiovascular risks.

Obesity, obstructive sleep apnoea, and diabetes mellitus: anaesthetic implications

Oxidative Stress in Blood Cells Associated with Obstructive Sleep Apnea Contributes to Absence of Hypoxia-Induced Polycythemia

Duration of positive airway pressure adherence: how much PAP is enough?

Background and Objectives: Cognitive deficits are common in obstructive sleep apnea (OSA), and both intermittent hypoxemia and cardiovascular comorbidity may contribute to poorer outcomes. Arterial hypertension (HTN) has been suggested as a potential modifier of cognitive function in OSA, but findings remain inconsistent. This study examined whether HTN influences baseline cognition or cognitive improvement after continuous positive airway pressure (CPAP) therapy in moderate-to-severe OSA and identified predictors of poorer post-treatment cognitive status. Materials and Methods: This prospective study involved 71 adults with newly diagnosed moderate-to-severe OSA (AHI ≥ 15). Participants underwent baseline polysomnography, Montreal Cognitive Assessment (MoCA) testing, and P300 assessments. Cognitive impairment was defined as MoCA < 26 and HTN by antihypertensive therapy, documented diagnosis, or repeatedly elevated blood pressure. All participants initiated auto-adjusting CPAP and were reassessed after three months for adherence, residual respiratory indices, MoCA, and P300 parameters. Multivariate logistic regression and receiver operating characteristic (ROC) analyses were used to identify independent predictors of poorer cognitive outcomes. Results: CPAP therapy significantly improved apnea severity, daytime sleepiness, global cognition, and P300 latency, while P300 amplitude did not change significantly. After three months, hypertensive and normotensive patients showed similar MoCA scores, respiratory outcomes, and P300 amplitude; P300 latency remained marginally longer in hypertensive individuals. Across multivariate models, lower mean nocturnal oxygen saturation and reduced CPAP adherence independently predicted poorer cognitive outcome at follow-up. CPAP adherence demonstrated greater discriminative ability than mean nocturnal oxygenation. Conclusions: In adequately treated moderate-to-severe OSA, HTN did not significantly affect baseline cognition or short-term cognitive recovery with CPAP. Although P300 latency remained slightly prolonged in hypertensive individuals, this difference was marginal and not accompanied by cognitive deficits. Nocturnal oxygenation and CPAP adherence emerged as the strongest predictors of post-treatment cognitive status, underscoring the importance of sustained and effective therapy. These findings suggest that effective CPAP adherence and improved nocturnal oxygenation are crucial for cognitive recovery in OSA patients, regardless of hypertensive status.

Commentary on Zheng Y, Yee BJ, Wong K, Grunstein R, Piper A. A pilot randomized trial comparing CPAP versus bilevel PAP spontaneous mode in the treatment of hypoventilation disorder in patients with obesity and obstructive airway disease. J Clin Sleep Med. 20XX;XX(XX):XXX-XXX. doi:10.5664/jcsm.9506.

Objective To evaluate serum soluble lectin-like oxidized low density lipoprotein receptor -1 (sLOX-1) level in patients with obstructive sleep apnea syndrome (OSAS) and effect of continuous positive airway pressure (CPAP) on serum sLOX-1 level in patients with OSAS. Methods Twenty cases of moderate and severe OSAS patients were selected as the OSAS group by means of polysomnography (PSG), and 15 healthy cases were enrolled as the control group. The serum sLOX-1 levels were measured in the OSAS group and the control group. After treatment with CPAP in the OSAS group, the serum sLOX-1 level was measured again. Results Before treatment, the serum sLOX-1 level was (105.26±37.47) pg/ml in the OSAS group, in which the serum sLOX-1 level was significantly higher than that in the control group [(99.98±18.78) pg/ml] (P < 0.05). After 1 week CPAP treatment in the OSAS group, the serum sLOX-1 level dropped to (93.34±21.24) pg/ml. Comparing the levels between before and after treatment, the difference was statistically significant (P < 0.05). Before treatment in the OSAS group, the serum sLOX-1 level was positively correlated with apnea hyponea index (AHI) (r = 0.416, P < 0.05). Conclusion The level of serum sLOX-1 increases in patients with OSAS. CPAP can effectively reduce the level of serum sLOX-1 in patients with OSAS. Key words: Obstructive sleep apnea syndrome; Continuous positive airway pressure; Soluble lectin-like oxidized low-density lipoprotein receptor-1