Triple trouble – new insights in the COPD-OSA overlap syndrome

<bold>Background:</bold> Chronic obstructive pulmonary disease (COPD) and congestive heart failure (CHF) often coexist, contributing to chronic inflammation, vascular dysfunction, and neuroendocrine activation, increasing the risk of adverse events. Our study aimed to elucidate the impact of comorbid obstructive sleep apnea (OSA) on COPD, with or without CHF, as OSA exacerbates these pathomechanisms. <bold>Methods:</bold> 181 COPD patients (mean age 69.4±9.4 years, BMI 28.0±6.1 kg/m2, 49.7% males) underwent standardized assessments including anthropometrics, comorbidities, arterial blood gas, and spirometry with DLCO% predicted. Overnight sleep studies (PAT system) identified significant OSA (AHI>15). CHF was determined by medical history and NTproBNP. Independent predictors of DLCO% were determined by regression analysis including anthropometrics, sleep apnea, lung function, and biomarkers (hsCRP, NTproBNP). <bold>Results:</bold> Of the patients, 71 (39.2%) had COPD alone, 23 (12.7%) had COPD+CHF, 48 (26.5%) had COPD+OSA overlap syndrome (OS), and 39 (21.5%) had combined OS+CHF. MRC, CAT, ESS scores, and FEV1% did not differ between groups. However, the 6 Minutes Walking test was significantly reduced (p=0.023) in OS+CHF. Deep sleep (p=0.002) and DLCO% (62.0±22.9%, 50.6±14.5%, 50.9±17.2%, 48.1±16.7%, p=0.014, respectively) were also reduced in OS+CHF. DLCO% was independently associated with BMI (β=0.842, p=0.003), FEV1% (β=0.479, p<0.001), and AHI (β=-0.290 p=0.032), but not age and NTproBNP. <bold>Conclusion:</bold> OS is highly prevalent in unselected COPD patients and is characterized by compromised DLCO%. OSA adds further burden to COPD patients, in particular to COPD patients with comorbid CHF - a true “triple trouble” important to recognize.