Abstract 17077: Nocturnal Intermittent Hypoxia and Short Sleep Duration were Independently Associated With Elevated C-reactive Protein Level in Patients With Coronary Artery Disease

Abstract

Introduction: There is growing evidence of a relationship between sleep disorders and cardiovascular diseases including coronary artery disease (CAD). However, the mechanism of these association is not well established. Enhanced vascular inflammation is implicated as a pathophysiologic mechanism in CAD. The aim of this study was to evaluate the relationship among sleep-disordered breathing (SDB), sleep duration, and serum C-reactive protein (CRP) level in patients with CAD. Methods and Results: Consecutive 225 patients with CAD who underwent percutaneous coronary intervention were evaluated. We used a nocturnal pulse oximetry as a non-invasive screening method for nocturnal intermittent hypoxia, a surrogate marker of SDB. Nocturnal intermittent hypoxia was evaluated using 3% oxygen desaturation index (3% ODI) which was the number of oxygen desaturation measurement ≤ 3% per hour, and we divided the patients into nocturnal intermittent hypoxia group (3% ODI≥15; n=64) and control group (3% ODI<15; n=161). Sleep quality was assessed using validated questionnaires (Pittsburgh Sleep Quality Index [PSQI]; 5.3±3.4, sleep duration; 385±83 minutes). Nocturnal intermittent hypoxia group had significantly higher BMI compared with control group, but age, gender, other coronary risk factors, sleep disturbance (PSQI≥8), sleep duration, and angiographic findings did not differ between two groups. Laboratory data showed that serum CRP level was significantly higher in patients with nocturnal intermittent hypoxia (0.15 [0.09-0.33] vs 0.06 [0.02-0.21] mg/dl, p=0.003). Short sleep duration (<6 hours) was also associated with increased CRP level (0.22 [0.04-0.40] vs 0.07 [0.03-0.14] mg/dl, p=0.036). In multiple regression analysis adjusted by age, gender, BMI, and acute coronary syndrome, 3% ODI (β=0.25; p=0.016; 95% CI, 0.153 to 1.475) and short sleep duration (β=0.20; p=0.04; 95% CI, 0.022 to 1.299) were independent determinants for log serum CRP level. Conclusions: Nocturnal intermittent hypoxia and short sleep duration were independently associated with elevated serum CRP level in CAD patients, suggesting that SDB and sleep duration could be important modifiable factors for the clinical management of patients with CAD.