0451 OVERLAP SYNDROME OF COPD AND OSA: METABOLIC RISK FACTORS AND SYSTEMIC INFLAMMATION

Abstract Introduction: Chronic obstructive pulmonary disease (COPD) and obstructive sleep apnea (OSA) are common and their co-occurrence, known as the overlap syndrome, is estimated in at least 1% of the general population. However, further knowledge is needed to fully characterize the overlap syndrome. Methods: We retrospectively studied 256 persons with stable COPD characterized in 2 previous physical activity studies. Body-mass index (BMI) was calculated from height and weight measured in the clinic. Participants were asked specifically if they had a diagnosis of OSA, hypertension (HTN), congestive heart failure (CHF), coronary artery disease (CAD), or diabetes mellitus (DM). CRP and IL-6 were determined using a high-sensitivity immunoturbidimetric assay with a sensitivity of 0.03 mg/L and 0.094 pg/mL, respectively. We compared characteristics between those with COPD-OSA (N=61) and those with COPD only (N=195) using unpaired T test, Wilcoxon rank sum test, or Chi square test, as appropriate. To assess the independent relationship between overlap syndrome and levels of CRP and IL-6, we used linear regression models (PROC GLM, SAS 9.4), adjusting for age, BMI, %predicted FEV1, pack-years, and history of CAD. Results: There was no difference between those with COPD-OSA and those with COPD only with respect to age (cohort mean 71 ± 8 years) and %predicted FEV1 (cohort mean 58 ± 21 %predicted). BMI and the prevalence of HTN and DM were significantly higher in the COPD-OSA group compared to the COPD only group. Persons with COPD-OSA were more likely to report CV disease including CAD and CHF, compared to those with COPD only. Both CRP (P=0.02) and IL-6 levels (P=0.02) were significantly higher in persons with COPD-OSA compared to persons with COPD only, after controlling for age, BMI, %predicted FEV1, pack-years, and history of CAD. Compared to COPD only, those with COPD-OSA had a 1.64 mg/L [95%CI: 1.09 to 2.48] increase in CRP and a 1.39 ng/mL [95%CI:1.06 to 1.81] increase in IL-6. Conclusion: Persons with COPD-OSA have a significantly higher prevalence of metabolic risk factors including higher BMI, HTN, and DM, higher levels of inflammatory biomarkers, and are more likely to have CV comorbidities than persons with COPD only. Support (If Any):