Continuous positive airway pressure treatment reduces cardiovascular death and non-fatal cardiovascular events in patients with obstructive sleep apnea: A meta-analysis of 11 studies

The Curious Role of PAI-1 in Severe Obstructive Sleep Apnea

Plasminogen activator inhibitor-1 (PAI-1) has a significant role in fibrinolysis, atherogenesis, cellular senescence, and chronic inflammation. OSA (obstructive sleep apnea) leads to increased PAI-1 levels and the development of cardiovascular disease (CVD). The aim of this study was to determine the effects of CPAP therapy on coagulation parameters and PAI-1 in patients with severe OSA. This prospective, controlled study enrolled 57 patients who were newly diagnosed with severe OSA, 37 of whom had had good CPAP adherence after 6 months of therapy (usage of the device for at least 4 h per night), and their data were analyzed. The analysis showed a statistically significant increase in D-dimer values before CPAP therapy (415 (316.5-537.5)) vs. after therapy (499 (327-652)), p = 0.0282, and a decrease in fibrinogen values (3.665 ± 0.752 before CPAP therapy vs. 3.365 ± 0.771 after therapy, p = 0.0075)). PAI-1 concentration values before and after CPAP therapy did not differ significantly (17.35 ± 7.01 ng/mL before CPAP therapy vs. 17.42 ± 6.99 ng/mL after therapy, p = 0.9367). This study shows a tendency for fibrinolytic capacity to improve in patients with OSA after CPAP therapy, although PAI-1 levels did not differ significantly.

Impact of Obstructive Sleep Apnea Treatment on Cardiovascular Disease Associated Mortality and Morbidity: A Systematic Review

The association between untreated obstructive sleep apnea (OSA) and cardiovascular disease (CVD) is well known. In this literature review, we aim to review the existing literature on treatment effects of OSA and its impact on CVD morbidity and mortality, stratified by gender. We systematically reviewed PubMed, Medline, and Scopus per PRISMA guidelines and included 25 studies in the final review. Primary outcomes were CVD-associated morbidity and mortality. Out of 25 studies, 10 were meta-analysis, 8 observational, and 7 randomized controlled trials. The treatment modality was continuous positive airway pressure (CPAP) in 23 studies, noninvasive positive pressure ventilation, and oral appliance therapy in 2. Secondary prevention of CVD was the endpoint in 23 studies. A total of 165,775 participants between 45 and 75 years of age, 60%-90% males, and the average Epworth Sleepiness Scale (ESS) score was 5-9. CV outcomes included myocardial infarction, angina, heart failure (HF), acute coronary syndrome (ACS), coronary artery disease (CAD), ischemic heart disease, cardiomyopathy, atrial fibrillation (AF), and hypertension. In 4 studies, CPAP was associated with a reduction in CVD mortality, and 10 studies showed improvement in morbidity. Our review of literature did not show consistent benefits in CV outcomes in OSA patients. We identified many potential research areas, especially the lack of studies demonstrating dose-dependent effect of OSA treatment on CV outcomes, especially when stratified by severity of OSA and gender. Larger prospective studies with longer follow-up will be helpful to study these parameters.

Obstructive sleep apnea-induced multi-organ dysfunction after elective coronary artery bypass surgery in coronary heart disease patients

Background

The aim of this study was to explore the underlying impact of obstructive sleep apnea (OSA) on postoperative parameters of multi-organ function among coronary heart disease (CHD) patients following elective coronary artery bypass grafting (CABG).

Methods

Electronic literature databases were searched manually and automatically for relevant English articles. All of the included articles focused on a comparison of the incidence of postoperative parameters of multi-organ function in CHD patients undergoing elective CABG with and without OSA. Studies were excluded if they met any one of the following criteria: (I) duplicate publication; (II) ongoing or unpublished studies; (III) only published as abstracts or conference proceedings; and (IV) less than 30 patients in the patient cohort.

Results

A total of 13 articles met our inclusion criteria. The current study demonstrated OSA significantly increased the incidence of major adverse cardiac and cerebrovascular events (MACCEs) in CHD patients undergoing elective CABG compared with the controls [odds risk (OR), 1.97; 95% CI, 1.50 to 2.59, P<0.0001]. In addition, OSA was associated with an increased risk of new revascularization in CHD patients undergoing elective CABG (OR, 9.47; 95% CI, 2.69 to 33.33, P<0.0001). Moreover, reintubation and tracheostomy in the OSA group was increased 243% (OR, 3.43; 95% CI, 1.35 to 8.71; P=0.009) and 372% (OR, 4.72; 95% CI, 1.23 to 18.13; P=0.024), respectively, compared with the control group. Besides, we also confirmed OSA significantly increased the acute kidney injury (AKI) incidence by 124% (OR, 2.24; 95% CI, 1.07 to 4.72; P<0.0001).

Conclusions

OSA may contribute to postoperative multi-organ dysfunction among CHD patients undergoing elective CABG by increasing the incidence of MACCEs, especially new revascularization, as well as respiratory, and renal complications.

Obstructive sleep apnea and effects of continuous positive airway pressure on triglyceride-rich lipoprotein metabolism

This study aimed to explore lipoprotein metabolism in obstructive sleep apnea (OSA) and the effects of continuous positive airway pressure (CPAP). We studied 15 men with severe OSA [apnea-hypopnea index (AHI) ≥30 events/hour] and 12 age-, BMI-, and waist circumference-matched volunteers without OSA (AHI <5 events/hour). Carotid intima-media thickness (CIMT) was determined by a blind examiner. After 12 h fasting, a triglyceride-rich chylomicron-like emulsion, labeled with [¹⁴C]cholesteryl oleate and [³H]triolein, was injected intravenously followed by blood sample collection at preestablished times. Fractional clearance rate (FCR) of the radiolabeled lipids was estimated by compartmental analysis of radioisotope decay curves. Compared with controls, patients with OSA showed a significant delay in both cholesteryl ester FCR (0.0126 ± 0.0187 vs. 0.0015 ± 0.0025 min^-1; P = 0.0313) and triglycerides FCR (0.0334 ± 0.0390 vs. 0.0051 ± 0.0074 min^-1; P = 0.0001). CIMT was higher in the OSA group: 620 ± 17 vs. 725 ± 29 µm; P = 0.004. Cholesteryl ester FCRs were inversely related to total sleep time <90% (r = -0.463; P = 0.029) and CIMT (r = -0.601; P = 0.022). The triglyceride FCR was inversely correlated with AHI (r = -0.537; P = 0.04). In a subgroup of patients treated with CPAP for 3 months (n = 7), triglyceride FCR increased 5-fold (P = 0.025), but the cholesteryl ester FCR was unchanged. In conclusion, severe OSA decreased lipolysis of triglyceride-rich lipoproteins and delayed removal of remnants. CPAP treatment may be effective to restore the lipolysis rates.

Prevalence and risk factors of moderate to severe obstructive sleep apnea syndrome in major depression: a observational and retrospective study on 703 subjects

Background

Several studies have investigated the prevalence and risk factors of depression in subjects with obstructive sleep apnea syndrome. However, few studies have investigated the prevalence and risk factors for obstructive sleep apnea syndrome in major depression. The aim of this study was to examine the prevalence and risk factors of moderate to severe obstructive sleep apnea syndrome in a large sample of individuals with major depression.

Methods

Data from 703 individuals with major depression recruited from the research database of the sleep laboratory of the Erasme Hospital were analysed. An apnea-hypopnea index of ≥15 events per hour was used as cut-off score for moderate to severe obstructive sleep apnea syndrome. Logistic regression analyses were conducted to examine clinical and demographic risk factors of moderate to severe obstructive sleep apnea syndrome in major depression.

Results

The prevalence of moderate to severe obstructive sleep apnea syndrome in major depression is 13.94%. Multivariate logistic regression analysis revealed that male gender, snoring, excessive daytime sleepiness, lower insomnia complaint, presence of metabolic syndrome, age ≥ 50 years, BMI >30 kg/m², ferritin >300 μg/L, CRP >7 mg/L and duration of sleep ≥8 h were significant risk factors of moderate to severe obstructive sleep apnea syndrome in major depression.

Conclusion

Moderate to severe obstructive sleep apnea syndrome is a common pathology in major depression. The identification of these different risk factors advances a new perspective for more effective screening of moderate to severe obstructive sleep apnea syndrome in major depression.

Prevalence and risk factors of moderate to severe obstructive sleep apnea syndrome in insomnia sufferers: a study on 1311 subjects

Background

Several studies have investigated the prevalence and risk factors of insomnia in subjects with obstructive sleep apnea syndrome. However, few studies have investigated the prevalence and risk factors for obstructive sleep apnea syndrome in insomnia sufferers. Thus, the aim of this study was to examine the prevalence and risk factors of moderate to severe obstructive sleep apnea syndrome in a large sample of insomnia sufferers.

Methods

Data from 1311 insomnia sufferers who were recruited from the research database of the sleep laboratory of the Erasme Hospital were analysed. An apnea-hypopnea index of ≥15 events per hour was used as the cut-off score for moderate to severe obstructive sleep apnea syndrome. Logistic regression analyses were conducted to examine clinical and demographic risk factors of moderate to severe obstructive sleep apnea syndrome in insomnia sufferers.

Results

The prevalence of moderate to severe obstructive sleep apnea syndrome in our sample of insomnia sufferers was 13.88%. Multivariate logistic regression analysis revealed that male gender, snoring, excessive daytime sleepiness, lower maintenance insomnia complaint, presence of metabolic syndrome, age ≥ 50 & <65 years, age ≥ 65 years, BMI ≥ 25 & <30 kg/m², BMI >30 kg/m², and CRP >7 mg/L were significant risk factors of moderate to severe obstructive sleep apnea syndrome in insomnia sufferers.

Conclusion

Moderate to severe obstructive sleep apnea syndrome is a common pathology in insomnia sufferers. The identification of these different risk factors advances a new perspective for more effective screening of moderate to severe obstructive sleep apnea syndrome in insomnia sufferers.

Effects of continuous positive airway pressure therapy on plasma aldosterone levels in patients with obstructive sleep apnea: A meta-analysis

Obstructive sleep apnea (OSA) is an independent risk factor for cardiovascular diseases. Aldosterone was reported to be increased in patients with OSA and correlated with OSA severity. Many studies investigated the effect of continuous positive airway pressure (CPAP) therapy on plasma aldosterone concentrations (PAC) in OSA patients. The results, however, were inconsistent. In the present study, we aimed to evaluate the effects of CPAP therapy on PAC by performing a meta-analysis. Literature search was carried out in electronic databases including PubMed/Medline, Cochrane Library, Embase and Web of Science. Eligible full-text articles were identified, and important data were extracted. Pooled analysis was performed using the STATA12.0 and RevMan 5.2. Standardized mean difference (SMD) was calculated to estimate the treatment effects. A total of eight studies involving 219 patients were included for our final analysis. PAC was found unchanged after CPAP treatment in OSA patients (SMD=-0.36, 95% CI:-0.91 to 0.18, Z=1.32, P=0.19). Meanwhile, CPAP therapy showed no impact on PAC (SMD=-0.21, 95% CI:-0.85 to 0.42, Z=0.66, P=0.51) in a separate meta-analysis including 3 randomized controlled trials. In conclusion, the evidence for the use of CPAP therapy to decrease PAC in OSA patients is low, and further studies are still warranted.

Non-alcoholic fatty liver disease and dyslipidemia: An update

Non-alcoholic fatty liver (NAFLD) is the most common liver disease worldwide, progressing from simple steatosis to necroinflammation and fibrosis (leading to non-alcoholic steatohepatitis, NASH), and in some cases to cirrhosis and hepatocellular carcinoma. Inflammation, oxidative stress and insulin resistance are involved in NAFLD development and progression. NAFLD has been associated with several cardiovascular (CV) risk factors including obesity, dyslipidemia, hyperglycemia, hypertension and smoking. NAFLD is also characterized by atherogenic dyslipidemia, postprandial lipemia and high-density lipoprotein (HDL) dysfunction. Most importantly, NAFLD patients have an increased risk for both liver and CV disease (CVD) morbidity and mortality. In this narrative review, the associations between NAFLD, dyslipidemia and vascular disease in NAFLD patients are discussed. NAFLD treatment is also reviewed with a focus on lipid-lowering drugs. Finally, future perspectives in terms of both NAFLD diagnostic biomarkers and therapeutic targets are considered.

Continuous positive airway pressure and survival of very elderly persons with moderate to severe obstructive sleep apnea

OBJECTIVE

There is evidence of a beneficial effect of long-term continuous positive airway pressure (CPAP) on survival in elderly persons with obstructive sleep apnea (OSA), although the usual age cut off is between 60 and 70 years of age. Our objective was to determine this effect in very elderly patients (ie, those ≥80 years of age).

METHODS

An observational study of a historic cohort of very elderly persons with moderate to severe OSA (apnea-hypopnea index ≥20) and the effect of long-term CPAP on their survival was performed. Two groups were formed: one prescribed CPAP treatment (≥4 hours per night), and one without CPAP treatment. Survival analyses, including Kaplan-Meier curves and Cox models, were carried out to determine the association of long-term CPAP with longer survival,

RESULTS

A total of 155 very elderly persons (84 men and 71 women, mean age 81.5 ± 1.5 years) were followed up for 53 months (interquartile range, 41-77 months); 83 deaths occurred. CPAP was prescribed to 132 patients, and adherence was observed in 79 (60%). Kaplan-Meier curves showed longer survival in the treated OSA group (91 months, 95% confidence interval [CI] = 76-106) than in the untreated OSA group (52 months, 95% CI 41-64), which was statistically significant (log-rank 16.9, p < 0.0001). Although history of stroke was significantly associated with higher mortality (hazard ratio [HR] = 2.18, 95% CI = 1.14-4.17, p = 0.02), CPAP treatment was associated with higher survival rates (HR = 0.46, 95% CI = 0.27-0.78, p = 0.004) in an adjusted Cox analysis.

CONCLUSIONS

CPAP treatment might be associated with a longer survival in very elderly persons with moderate to severe OSA.