Serum levels of high sensitivity cardiac troponin and B-type natriuretic peptide in patients with COPD-OSA overlap syndrome

Abstract

Introduction: Evidence shows that COPD-OSA overlap syndrome (OS) is more frequently accompanied by cardiovascular disease (CVD) in comparison to either disease alone. The aim of this study is to compare indices of asymptomatic myocardial injury between OS and OSA patients. Methods: Consecutive patients, without a known history of CVD, underwent polysomnography and pulmonary function testing, due to suspected sleep-disordered breathing. An equal number of patients with OS (n=53, with Apnea Hypopnea Index (AHI)g5/h and FEV1/FVCl0.7) and patients with OSA (n=53, AHIg5/h και FEV1/FVCg0.7) were included in the study. Detection of asymptomatic myocardial injury was performed by assessment of serum B-type natriuretic peptide (proBNP) and high sensitivity cardiac troponin (hsTrop) among all participants. Results: OS patients were older (pl0.001) with worse indices of hypoxemia, namely average SpO2 (p=0.002), Tl90% (p=0.003) during sleep and lower daytime pO2 (pl0.001) than OSA. No difference was observed between groups in terms of Epworth Sleepiness Scale (p=0.432), AHI (p=0.587), fasting glucose (p=0.703), lipidemic profile and parameters of renal function. Both serum levels of hsTrop [14.2 (9.1–20.2) vs. 6.5 (5.6–8.7) pg/ml, pl0.001] and proBNP [93.1 (37.9–182.5) vs. 19.2 (8.3–35.4) pg/ml, pl0.001] were increased in OS patients compared to OSA individuals. At multivariate linear regression analysis, both proBNP and hsTrop serum levels correlated with age and average SpO2 during sleep. Conclusions: Serum levels of hsTrop and proBNP in OS patients are increased, indicating a higher probability of latent myocardial injury, compared with OSA individuals.