Association Between Severity of Obstructive Sleep Apnea and Blood Markers of Liver Injury.

Obstructive sleep apnea (OSA) may contribute to the development of nonalcoholic fatty liver disease. We performed a multisite cross-sectional study to evaluate the association between the severity of OSA and blood markers of liver steatosis (using the hepatic steatosis index), cytolysis (based on alanine aminotransferase activity), and significant liver fibrosis (based on the FibroMeter [Echosens] nonalcoholic fatty liver disease score) in 1285 patients with suspected OSA in France. After adjusting for confounders including central obesity, the risk of liver steatosis increased with the severity of OSA (P for trend < .0001) and sleep-related hypoxemia (P for trend < .0003 for mean oxygen saturation). Decreasing mean oxygen saturation during sleep also was associated independently with a higher risk of liver cytolysis (P for trend < .0048). Severe OSA conferred an approximate 2.5-fold increase in risk for significant liver fibrosis compared with patients without OSA, but the association between OSA severity and liver fibrosis was not maintained after adjusting for confounders.

Association between obstructive sleep apnea severity and glucose control in patients with untreated versus treated diabetes.

The purpose of this study was to determine whether the association between obstructive sleep apnea severity and glucose control differs between patients with newly diagnosed and untreated type 2 diabetes, and patients with known and treated type 2 diabetes. This multicentre cross-sectional study included 762 patients investigated by sleep recording for suspected obstructive sleep apnea, 497 of whom were previously diagnosed and treated for type 2 diabetes (treated diabetic patients), while 265 had no medical history of diabetes but had fasting blood glucose ≥126 mg dL(-1) and/or glycated haemoglobin (HbA1c ) ≥6.5% consistent with newly diagnosed type 2 diabetes (untreated diabetic patients). Multivariate regression analyses were performed to evaluate the independent association between HbA1c and obstructive sleep apnea severity in treated and untreated patients with diabetes. In untreated diabetic patients, HbA1c was positively associated with apnea-hypopnea index (P = 0.0007) and 3% oxygen desaturation index (P = 0.0016) after adjustment for age, gender, body mass index, alcohol habits, metabolic dyslipidaemia, hypertension, statin use and study site. The adjusted mean value of HbA1c increased from 6.68% in the lowest quartile of the apnea-hypopnea index (<17) to 7.20% in the highest quartile of the apnea-hypopnea index (>61; P = 0.033 for linear trend). In treated patients with diabetes, HbA1c was associated with non-sleep variables, including age, metabolic dyslipidaemia and insulin use, but not with obstructive sleep apnea severity. Obstructive sleep apnea may adversely affect glucose control in patients with newly diagnosed and untreated type 2 diabetes, but may have a limited impact in patients with overt type 2 diabetes receiving anti-diabetic medications.

Noninvasive Ventilation in Obese Subjects After Acute Respiratory Failure.

INTRODUCTION: Noninvasive ventilation (NIV) has been widely used to treat acute respiratory failure in obese patients. Criteria that could help clinicians to decide whether they should continue to use NIV after such an initial episode remain unclear. Our retrospective study aims to analyze characteristics of subjects receiving long-term NIV after an initial hospitalization for acute respiratory failure. METHODS: From January 2011 to December 2012, 77 obese adults were admitted in the ICU of the respiratory disease department in Nantes University Hospital in France. After discharge, adherence, body mass index (BMI), and arterial blood gases were assessed or measured at 6 months and 12 months. RESULTS: In all, 53 subjects were analyzed, including 62% who were admitted for idiopathic acute hypercapnic respiratory failure. Mean BMI was 42 ± 11 kg/m2. Failure of NIV occurred in 10% cases in the ICU. At the end of the hospital stay, 34 subjects were discharged with NIV at home. They had higher BMI and higher initial inspiratory positive airway pressure than those who were not ventilated at home. During follow-up, BMI, PaCO2 , and bicarbonate rate significantly decreased. At 12 months, 4 subjects were not ventilated anymore after a mean duration of 6 ± 4.2 months of ventilation. Adherence was correct in 86%, with a mean use of 7 ± 3.1 h/d. Adherent subjects had better adherence at 1 month, a lower forced vital capacity, a higher bicarbonate rate, and a higher NIV breathing frequency when compared to subjects with poor adherence. CONCLUSIONS: Subjects with the most severe obesity or who experienced the most difficult initial ventilation were more likely to receive long-term NIV after initial management of acute respiratory failure in the ICU. In those subjects, long-term NIV at home was effective and well tolerated.

Home Non-Invasive Ventilation Fails to Improve Quality of Life in the Elderly: Results from a Multicenter Cohort Study.

BACKGROUND: Home non-invasive ventilation (NIV) is a widely used treatment for chronic hypoventilation but little is known on its impact in the elderly. In a multicenter prospective cohort study, we studied tolerance and efficacy of domiciliary NIV in patients aged 75 or more compared to younger ones. METHODS AND RESULTS: 264 patients with at least a six-month follow-up were analyzed. Among them, 82 were elderly. In the elderly and the younger, we found an improvement of arterial blood gas, the Epworth sleepiness scale and the Pittsburgh sleep quality index at 6 months. Mean daily use of NIV at 6 months was 7 hours and the rate of non-adherent patients was similar in both group. Health-related quality of life (HRQL) assessed by SF-36 questionnaires did not change significantly after NIV initiation in the elderly whereas HRQL improved in the less than 75. On univariate analysis, we found that diabetes was a predictive factor for non-adherence in the elderly (Odds ratio: 3.95% confidence interval: 1.06-8.52). CONCLUSION: NIV was efficient in the elderly while evaluation at 6 months showed a good adherence but failed to improve HRQL.

Depressive symptoms before and after long-term CPAP therapy in patients with sleep apnea.

BACKGROUND: The outcome of depressive symptoms under CPAP therapy for OSA-hypopnea syndrome (OSAHS) has been poorly evaluated. In this multicenter, prospective cohort study, we evaluated the prevalence and correlates of persistent depressive symptoms after long-term CPAP therapy for OSAHS. METHODS: This study included 300 patients with OSAHS and depressive symptoms (13-item, self-rated Pichot depression scale [QD2A] ≥ 7) at diagnosis. The primary dependent variable was persistent depressive symptoms after ≥ 1 year of CPAP therapy. Multivariate regression analyses were performed to determine variables independently associated with the persistence of depressive symptoms. RESULTS: After an average of 529 days (range, 365-1,569 days) of CPAP therapy, the mean (SD) QD2A score decreased from 9.2 (2.0) to 5.4 (4.0) (P < .0001), but 125 patients (41.7%) presented persistent depressive symptoms. The persistence of depressive symptoms was independently associated with persistent excessive daytime sleepiness (EDS) (OR, 2.72; 95% CI, 1.33-5.61), comorbid cardiovascular disease (OR, 1.76; 95% CI, 1.02-3.00), and female sex (OR, 1.53; 95% CI, 1.09-2.13). A positive linear trend was observed for the adjusted OR of persistent depressive symptoms with decreasing CPAP effect on the Epworth sleepiness scale (P < .0001). CONCLUSIONS: CPAP therapy does not resolve depressive symptoms in many patients with OSAHS. Persistent depressive symptoms are strongly associated with EDS. Active monitoring of depressive symptoms is needed in patients with OSAHS who are treated with CPAP. Interventional trials are required to evaluate the impact of antidepressants, cognitive behavioral therapy, or both on comorbid depression in patients with OSAHS.

Independent association between nocturnal intermittent hypoxemia and metabolic dyslipidemia.

BACKGROUND: There is growing evidence from animal models that intermittent hypoxemia (IH) may induce dyslipidemia. Altered lipid metabolism may contribute to the increased cardiovascular risk observed in obstructive sleep apnea (OSA). In this multisite, cross-sectional study, we tested the hypothesis that there is an independent association between nocturnal IH and dyslipidemia in OSA. METHODS: Fasting serum lipid levels were measured in 2,081 patients (638 women) undergoing nocturnal recording for clinical suspicion of OSA. Multivariate regression analyses were performed to evaluate the independent associations between oxygen desaturation index (ODI) and lipid profile after adjustment for potential confounders, including components of the metabolic syndrome (MS) or the MS itself. Adjusted OR for metabolic dyslipidemia (triglycerides [TG] ≥ 150 mg/dL and high-density lipoprotein cholesterol [HDL-C] ≤ 50 mg/dL for women and ≤ 40 mg/dL for men) according to quartiles of ODI were determined by logistic regression. RESULTS: Total cholesterol and low-density lipoprotein cholesterol were not associated with ODI. In contrast, nocturnal IH and OSA severity were associated with higher TG levels and lower HDL-C levels after adjustment for confounding factors. The association between ODI and TG and HDL-C levels was independent of the MS. Adjusted OR (95% CIs) for metabolic dyslipidemia were 1 (reference), 1.56 (1.24-1.96), 1.72 (1.29-2.29), and 1.93 (1.55-2.41) for ODI ≤ 7, > 7 to ≤ 18, > 18 to ≤ 38, and > 38, respectively (P < .0001 for linear trend). CONCLUSIONS: Nocturnal IH is independently associated with metabolic dyslipidemia, which may predispose patients with OSA to a higher risk of cardiovascular disease.

Independent association between obstructive sleep apnea severity and glycated hemoglobin in adults without diabetes.

OBJECTIVE: We tested the hypothesis of an independent cross-sectional association between obstructive sleep apnea (OSA) severity and glycated hemoglobin (HbA(1c)) in adults without known diabetes. RESEARCH DESIGN AND METHODS: HbA(1c) was measured in whole-blood samples from 2,139 patients undergoing nocturnal recording for suspected OSA. Participants with self-reported diabetes, use of diabetes medication, or HbA(1c) value ≥6.5% were excluded from this study. Our final sample size comprised 1,599 patients. RESULTS: A dose-response relationship was observed between apnea-hypopnea index (AHI) and the percentage of patients with HbA(1c) >6.0%, ranging from 10.8% for AHI <5 to 34.2% for AHI ≥50. After adjustment for age, sex, smoking habits, BMI, waist circumference, cardiovascular morbidity, daytime sleepiness, depression, insomnia, sleep duration, and study site, odds ratios (95% CIs) for HbA(1c) >6.0% were 1 (reference), 1.40 (0.84-2.32), 1.80 (1.19-2.72), 2.02 (1.31-3.14), and 2.96 (1.58-5.54) for AHI values <5, 5 to <15, 15 to <30, 30 to <50, and ≥50, respectively. Increasing hypoxemia during sleep was also independently associated with the odds of HbA(1c) >6.0%. CONCLUSIONS: Among adults without known diabetes, increasing OSA severity is independently associated with impaired glucose metabolism, as assessed by higher HbA(1c) values, which may expose them to higher risks of diabetes and cardiovascular disease.

Influence of marital status and employment status on long-term adherence with continuous positive airway pressure in sleep apnea patients.

BACKGROUND: Long-term adherence is a major issue in patients receiving home continuous positive airway pressure (CPAP) therapy for obstructive sleep apnea-hypopnea syndrome (OSAHS). In a multicenter prospective cohort (the Institut de Recherche en Santé Respiratoire des Pays de la Loire [IRSR] sleep cohort) of consecutive OSAHS patients in whom CPAP had been prescribed for at least 90 days, we studied the impact on long-term treatment adherence of socioeconomic factors, patients and disease characteristics prior to CPAP initiation. METHODS AND PRINCIPAL FINDINGS: Among 1,141 patients in whom CPAP had been prescribed for an average of 504±251 days (range: 91 to 1035), 674 (59%) were adherent with a mean daily use of CPAP≥4 h (mean: 6.42±1.35 h). Stepwise regression analysis identified 4 independent factors of CPAP adherence including apnea-hypopnea index (AHI) (OR: 1.549, 95%CI 1.163 to 2.062 for AHI≥30 vs. AHI<30; p = 0.003), body mass index (BMI) (OR: 1.786, 95%CI 1.131 to 2.822 for BMI≥25 and <30 kg/m(2), p = 0.01; OR: 1.768, 95%CI 1.145-2.731 for BMI≥30 kg/m(2), p = 0.01 vs. BMI<25 kg/m(2)), employment status (OR: 1.414, 95%CI 1.097-1.821 for retired vs. employed; p = 0.007) and marital status (OR: 1.482, 95%CI 1.088-2.019 for married or living as a couple vs. living alone; p = 0.01). Age, gender, Epworth sleepiness scale, depressive syndrome, associated cardiovascular morbidities, educational attainment and occupation category did not influence CPAP adherence. CONCLUSIONS: Marital status and employment status are independent factors of CPAP adherence in addition to BMI and disease severity. Patients living alone and/or working patients are at greater risk of non-adherence, whereas adherence is higher in married and retired patients. These findings suggest that the social context of daily life should be taken into account in risk screening for CPAP non-adherence. Future interventional studies targeting at-risk patients should be designed to address social motivating factors and work-related barriers to CPAP adherence.