Upper airway and systemic inflammation in obstructive sleep apnoea.

Obstructive sleep apnoea (OSA) is associated with pharyngeal inflammation, but the coexistence of systemic inflammation is controversial. This study investigated whether local and systemic inflammatory biomarkers are related in patients with OSA. An uncontrolled extension to the study assessed the response to effective treatment.We recruited 89 patients with OSA (apnoea/hypopnoea index (AHI) ≥5 events·h-1), 28 snorers and 26 healthy controls. Pharyngeal lavage (PHAL) and plasma samples were collected at baseline and after a 1-year follow-up. Inflammatory cells were evaluated by flow cytometry; interleukin (IL)-6, IL-8 and tumour necrosis factor-α were evaluated by immunoassay.In PHAL, CD4+ T-cells, IL-6 and IL-8 were higher in OSA patients than in snorers or healthy controls (p<0.05). The AHI correlated with CD4+, IL-6 and IL-8 in PHAL (all p-values <0.05). There were no differences in the inflammatory biomarkers in plasma between the study groups and no relationship between plasma and PHAL biomarkers. Biomarkers decreased significantly in PHAL but not in plasma after 1 year of therapy with continuous positive airway pressure or surgery.In patients with OSA, increased levels of inflammatory biomarkers were found in PHAL, which were reduced with effective treatment. No simultaneous increase in plasma inflammatory biomarkers was found.

Non-invasive ventilation in obesity hypoventilation syndrome without severe obstructive sleep apnoea.

BACKGROUND: Non-invasive ventilation (NIV) is an effective form of treatment in patients with obesity hypoventilation syndrome (OHS) who have concomitant severe obstructive sleep apnoea (OSA). However, there is a paucity of evidence on the efficacy of NIV in patients with OHS without severe OSA. We performed a multicentre randomised clinical trial to determine the comparative efficacy of NIV versus lifestyle modification (control group) using daytime arterial carbon dioxide tension (PaCO2) as the main outcome measure. METHODS: Between May 2009 and December 2014 we sequentially screened patients with OHS without severe OSA. Participants were randomised to NIV versus lifestyle modification and were followed for 2 months. Arterial blood gas parameters, clinical symptoms, health-related quality of life assessments, polysomnography, spirometry, 6-min walk distance test, blood pressure measurements and healthcare resource utilisation were evaluated. Statistical analysis was performed using intention-to-treat analysis. RESULTS: A total of 365 patients were screened of whom 58 were excluded. Severe OSA was present in 221 and the remaining 86 patients without severe OSA were randomised. NIV led to a significantly larger improvement in PaCO2 of -6 (95% CI -7.7 to -4.2) mm Hg versus -2.8 (95% CI -4.3 to -1.3) mm Hg, (p<0.001) and serum bicarbonate of -3.4 (95% CI -4.5 to -2.3) versus -1 (95% CI -1.7 to -0.2 95% CI)  mmol/L (p<0.001). PaCO2 change adjusted for NIV compliance did not further improve the inter-group statistical significance. Sleepiness, some health-related quality of life assessments and polysomnographic parameters improved significantly more with NIV than with lifestyle modification. Additionally, there was a tendency towards lower healthcare resource utilisation in the NIV group. CONCLUSIONS: NIV is more effective than lifestyle modification in improving daytime PaCO2, sleepiness and polysomnographic parameters. Long-term prospective studies are necessary to determine whether NIV reduces healthcare resource utilisation, cardiovascular events and mortality. TRIAL REGISTRATION NUMBER: NCT01405976; results.

Epigenetics modifications and Subclinical Atherosclerosis in Obstructive Sleep Apnea: The EPIOSA study.

BACKGROUND: Obstructive sleep apnea (OSA) is associated with increased risk for cardiovascular morbidity and mortality. Epidemiological and animal models studies generate hypotheses for innovative strategies in OSA management by interfering intermediates mechanisms associated with cardiovascular complications. We have thus initiated the Epigenetics modification in Obstructive Sleep Apnea (EPIOSA) study (ClinicalTrials.gov identifier: NCT02131610). METHODS/DESIGN: EPIOSA is a prospective cohort study aiming to recruit 350 participants of caucasian ethnicity and free of other chronic or inflammatory diseases: 300 patients with prevalent OSA and 50 non-OSA subjects. All of them will be follow-up for at least 5 years. Recruitment and study visits are performed in single University-based sleep clinic using standard operating procedures. At baseline and at each one year follow-up examination, patients are subjected to a core phenotyping protocol. This includes a standardized questionnaire and physical examination to determine incident comorbidities and health resources utilization, with a primary focus on cardiovascular events. Confirmatory outcomes information is requested from patient records and the regional Department of Health Services. Every year, OSA status will be assessed by full sleep study and blood samples will be obtained for immediate standard biochemistry, hematology, inflammatory cytokines and cytometry analysis. For biobanking, aliquots of serum, plasma, urine, mRNA and DNA are also obtained. Bilateral carotid echography will be performed to assess subclinical atherosclerosis and atherosclerosis progression. OSA patients are treated according with national guidelines. DISCUSSION: EPIOSA will enable the prospective evaluation of inflammatory and epigenetics mechanism involved in cardiovascular complication of treated and non-treated patients with OSA compared with non OSA subjects.

Association between treated and untreated obstructive sleep apnea and risk of hypertension.

CONTEXT: Systemic hypertension is prevalent among patients with obstructive sleep apnea (OSA). Short-term studies indicate that continuous positive airway pressure (CPAP) therapy reduces blood pressure in patients with hypertension and OSA. OBJECTIVE: To determine whether CPAP therapy is associated with a lower risk of incident hypertension. DESIGN, SETTING, AND PARTICIPANTS: A prospective cohort study of 1889 participants without hypertension who were referred to a sleep center in Zaragoza, Spain, for nocturnal polysomnography between January 1, 1994, and December 31, 2000. Incident hypertension was documented at annual follow-up visits up to January 1, 2011. Multivariable models adjusted for confounding factors, including change in body mass index from baseline to censored time, were used to calculate hazard ratios (HRs) of incident hypertension in participants without OSA (controls), with untreated OSA, and in those treated with CPAP therapy according to national guidelines. MAIN OUTCOME MEASURE: Incidence of new-onset hypertension. RESULTS: During 21,003 person-years of follow-up (median, 12.2 years), 705 cases (37.3%) of incident hypertension were observed. The crude incidence of hypertension per 100 person-years was 2.19 (95% CI, 1.71-2.67) in controls, 3.34 (95% CI, 2.85-3.82) in patients with OSA ineligible for CPAP therapy, 5.84 (95% CI, 4.82-6.86) in patients with OSA who declined CPAP therapy, 5.12 (95% CI, 3.76-6.47) in patients with OSA nonadherent to CPAP therapy, and 3.06 (95% CI, 2.70-3.41) in patients with OSA and treated with CPAP therapy. Compared with controls, the adjusted HRs for incident hypertension were greater among patients with OSA ineligible for CPAP therapy (1.33; 95% CI, 1.01-1.75), among those who declined CPAP therapy (1.96; 95% CI, 1.44-2.66), and among those nonadherent to CPAP therapy (1.78; 95% CI, 1.23-2.58), whereas the HR was lower in patients with OSA who were treated with CPAP therapy (0.71; 95% CI, 0.53-0.94). CONCLUSION: Compared with participants without OSA, the presence of OSA was associated with increased adjusted risk of incident hypertension; however, treatment with CPAP therapy was associated with a lower risk of hypertension.

Prognostic assessment in COPD: health related quality of life and the BODE index.

RATIONALE: COPD is a debilitating disease with increasing mortality worldwide. The BODE index evaluates disease severity and the St George's Respiratory Questionnaire (SGRQ) measures health status. OBJECTIVE: To identify the relationship between BODE index and the SGRQ and to test the predictive value of both tools against survival. METHODS: Open cohort study of 1398 COPD patients (85% male) followed for up to 10 years. MEASUREMENTS AND MAIN RESULTS: At the time of the inclusion, clinical data, forced spirometry and 6 min walking distance were determined and BODE index and SGRQ were calculated. Vital status and cause of death were documented at the end of follow-up. RESULTS: The cohort's mean of FEV1% predicted was 46 ± 18%, BODE index was 3.6 ± 2.5, and SGRQ% total score was 49 ± 20. The SGRQ scores increased progressively as severity of COPD increased by BODE quartiles. The correlation between SGRQ and BODE index was good (r = 0.58, p < 0.0001). Both tests correlated with COPD survival (BODE = -0.4 vs. SGRQ = -0.20, p < 0.0001). The area under the curve (AUC) for the BODE index was 0.77 vs. 0.66 for the SGRQ % total score (p < 0.001). CONCLUSIONS: Health status as measured by SGRQ worsens with disease severity evaluated by the BODE index. Both tools predict mortality and provide complimentary information in the evaluation of patients with COPD.

Outcomes in patients with chronic obstructive pulmonary disease and obstructive sleep apnea: the overlap syndrome.

RATIONALE: Patients with chronic obstructive pulmonary disease (COPD) and obstructive sleep apnea (OSA) (overlap syndrome) are more likely to develop pulmonary hypertension than patients with either condition alone. OBJECTIVES: To assess the relation of overlap syndrome to mortality and first-time hospitalization because of COPD exacerbation and the effect of continuous positive airway pressure (CPAP) on these major outcomes. METHODS: We included 228 patients with overlap syndrome treated with CPAP, 213 patients with overlap syndrome not treated with CPAP, and 210 patients with COPD without OSA. All were free of heart failure, myocardial infarction, or stroke. Median follow-up was 9.4 years (range, 3.3-12.7). End points were all-cause mortality and first-time COPD exacerbation leading to hospitalization. MEASUREMENTS AND MAIN RESULTS: After adjustment for age, sex, body mass index, smoking status, alcohol consumption, comorbidities, severity of COPD, apnea-hypopnea index, and daytime sleepiness, patients with overlap syndrome not treated with CPAP had a higher mortality (relative risk, 1.79; 95% confidence interval, 1.16-2.77) and were more likely to suffer a severe COPD exacerbation leading to hospitalization (relative risk, 1.70; 95% confidence interval, 1.21-2.38) versus the COPD-only group. Patients with overlap syndrome treated with CPAP had no increased risk for either outcome compared with patients with COPD-only. CONCLUSIONS: The overlap syndrome is associated with an increased risk of death and hospitalization because of COPD exacerbation. CPAP treatment was associated with improved survival and decreased hospitalizations in patients with overlap syndrome.

Prediction of risk of COPD exacerbations by the BODE index.

OBJECTIVES: This study assesses the power of the BODE index, a multidimensional grading system that predicts mortality, to predict subsequent exacerbations in patients with COPD. DESIGN: Prospective cohort study. PATIENTS AND INTERVENTIONS: A total of 275 COPD patients were followed every 6 months up to 8 years (median of 5.1 years). Baseline clinical variables were recorded and the BODE index was calculated. We investigated the prognostic value of BODE quartiles (scores 0-2, 3-4, 5-6 and 7-10) for both the number and severity of exacerbations requiring ambulatory treatment, emergency room visit, or hospitalization. RESULTS: The annual rate of COPD exacerbations was 1.95 (95% CI, 0.90-2.1). The mean time to a first exacerbation was inversely proportional to the worsening of the BODE quartiles (7.9 yrs, 5.7 yrs, 3.4 yrs and 1.3 yrs for BODE scores of 0-2, 3-4, 5-6 and 7-10, respectively). Similarly, the mean time to a first COPD emergency room visit was 6.7 yrs, 3.6 yrs, 2.0 yrs and 0.8 yrs for BODE quartiles (all p<0.05). Using ROC curves, the BODE index was a better predictor of exacerbation than the FEV(1) alone (p<0.01). CONCLUSIONS: The BODE index is a better predictor of the number and severity of exacerbations in COPD than FEV(1) alone.

Long-term cardiovascular outcomes in men with obstructive sleep apnoea-hypopnoea with or without treatment with continuous positive airway pressure: an observational study.

BACKGROUND: The effect of obstructive sleep apnoea-hypopnoea as a cardiovascular risk factor and the potential protective effect of its treatment with continuous positive airway pressure (CPAP) is unclear. We did an observational study to compare incidence of fatal and non-fatal cardiovascular events in simple snorers, patients with untreated obstructive sleep apnoea-hypopnoea, patients treated with CPAP, and healthy men recruited from the general population. METHODS: We recruited men with obstructive sleep apnoea-hypopnoea or simple snorers from a sleep clinic, and a population-based sample of healthy men, matched for age and body-mass index with the patients with untreated severe obstructive sleep apnoea-hypopnoea. The presence and severity of the disorder was determined with full polysomnography, and the apnoea-hypopnoea index (AHI) was calculated as the average number of apnoeas and hypopnoeas per hour of sleep. Participants were followed-up at least once per year for a mean of 10.1 years (SD 1.6) and CPAP compliance was checked with the built-in meter. Endpoints were fatal cardiovascular events (death from myocardial infarction or stroke) and non-fatal cardiovascular events (non-fatal myocardial infarction, non-fatal stroke, coronary artery bypass surgery, and percutaneous transluminal coronary angiography). FINDINGS: 264 healthy men, 377 simple snorers, 403 with untreated mild-moderate obstructive sleep apnoea-hypopnoea, 235 with untreated severe disease, and 372 with the disease and treated with CPAP were included in the analysis. Patients with untreated severe disease had a higher incidence of fatal cardiovascular events (1.06 per 100 person-years) and non-fatal cardiovascular events (2.13 per 100 person-years) than did untreated patients with mild-moderate disease (0.55, p=0.02 and 0.89, p<0.0001), simple snorers (0.34, p=0.0006 and 0.58, p<0.0001), patients treated with CPAP (0.35, p=0.0008 and 0.64, p<0.0001), and healthy participants (0.3, p=0.0012 and 0.45, p<0.0001). Multivariate analysis, adjusted for potential confounders, showed that untreated severe obstructive sleep apnoea-hypopnoea significantly increased the risk of fatal (odds ratio 2.87, 95%CI 1.17-7.51) and non-fatal (3.17, 1.12-7.51) cardiovascular events compared with healthy participants. INTERPRETATION: In men, severe obstructive sleep apnoea-hypopnoea significantly increases the risk of fatal and non-fatal cardiovascular events. CPAP treatment reduces this risk.