Increased Plasma Levels of Asymmetric Dimethylarginine and Soluble CD40 Ligand in Patients with Sleep Apnea

Background: Cardiovascular (CV) diseases are a leading cause of mortality and they are frequent in patients with the obstructive sleep apnea syndrome (OSAS). Objectives: In this study we investigated if OSAS influences CV function independently of other CV risk factors frequently present in these patients (e.g. obesity, high blood pressure). Methods: We compared plasma markers of endothelial dysfunction, asymmetric dimethylarginine (ADMA) and endothelin-1 (ET-1), and atherosclerosis progression (soluble fraction of the CD40 ligand, sCD40L) in OSAS patients with (n = 23) and without (n = 18) concurrent CV risk factors, as well as in healthy subjects (n = 23). Results: Plasma ADMA (p < 0.01) and sCD40L (p < 0.05) were abnormally increased in patients with OSAS versus healthy controls, but they were not influenced by the presence or absence of CV risk factors in OSAS. ET-1 levels were not different between the three groups of subjects studied. Conclusions: OSAS is associated with endothelial injury and atherosclerosis progression independently of other CV risk factors.