Purpose: Systemic inflammation is important in the pathogenesis of cardiovascular disease (CVD). We sought to characterize the systemic inflammatory profile associated with obstructive sleep apnea (OSA).
Methods: Adult patients referred for suspected OSA at the University of British Columbia Hospital Sleep Disorders Program were recruited for our study. Patients using HMG CoA inhibitors or a history of CVD were excluded. Fasting serum samples were obtained the morning after their diagnostic polysomnograms. Samples were tested for the following circulating inflammatory mediators: interferon gamma; interleukins 1B, 6, and 8; intercellular and vascular cell adhesion molecules (sICAM-1 and sVCAM-1); and leptin using a multiplex Luminex System.
Results: There were 176 patients; 68% were male, mean age = 50 +/- (SD) 11 years, mean apnea/hyponea index (AHI) = 22.9 +/- 22/h, mean desaturation (i.e. % of sleep time spent below an oxyhemoglobin saturation of 90%) = 5.4% +/- 15, and mean body mass index (BMI) = 32.2 +/- 8 kg/m(2). In univariate analyses, only leptin, sVCAM-1, and sICAM-1 were significantly associated with indices of OSA severity (i.e. AHI and/or desaturation). In multivariate linear regression analyses that controlled for BMI, gender, age, and current smoking; desaturation persisted as a significant independent predictor for elevated sVCAM-1 and leptin.
Conclusions: We did not find significant associations between OSA and markers of activated innate immunity (IL-1B, 6, and 8). However, OSA severity was independently associated with serum levels of sVCAM-1 and leptin; these may represent mechanisms involved in the pathogenesis of OSA-related CVD.