Cell Death Biomarkers and Obstructive Sleep Apnea: Implications in the Acute Coronary Syndrome

Study Objectives: Nucleosomes and cell-free double-stranded DNA (dsDNA) have been suggested as promising biomarkers in cell death-related diseases, such as acute coronary syndrome (ACS). Currently, the impact of obstructive sleep apnea (OSA) in patients with ACS is unclear. Our aim was to evaluate the relationship between OSA, dsDNA, and nucleosomes and to assess their potential implication in the development of ACS. Methods: Up to 549 patients were included in the study and divided into four groups (145 ACS; 290 ACS + OSA; 62 OSA; 52 controls). All patients underwent a sleep study, and serum concentrations of dsDNA and nucleosomes were measured. Results: Nucleosome and dsDNA levels were higher in patients with OSA than in controls (nucleosomes: 1.47 +/- 0.88 arbitary units [ AU] vs. 1.00 +/- 0.33 AU; p <.001, dsDNA: 315.6 +/- 78.0 ng/mL vs. 282.6 +/- 55.4 ng/mL; p =.007). In addition, both biomarker levels were higher in patients with ACS than in non-ACS, independently of the presence of OSA. Conclusions: Both nucleosomes and dsDNA are increased in patients with OSA and might be related with the high cardiovascular risk seen in these patients. The extensive cell lysis during a myocardial infarction seems to be the major contributor to the high biomarker levels, and OSA does not seem to be implicated in such elevation when this acute event occurs.