Influence of obstructive sleep apnea on ischemia-modified albumin levels and carotid intima-media thickness

Abstract

Obstructive sleep apnea (OSA) is associated with an increased risk of atherosclerosis. Carotid intima-media thickness (CIMT) is strongly associated with the presence of significant risk factors for cardiovascular disturbances. A disturbance in the oxidative/antioxidative balance is involved in the pathogenesis of OSA and cardiovascular diseases. Ischemia-modified albumin (IMA) is suggested as a novel marker of oxidative stress; IMA can be defined as decreased binding of transitional metal ions to serum albumin in oxidative status. The purpose of this research was to evaluate the influence of OSA on IMA levels and CIMT. In total, 61 individuals with OSA with no comorbidities and 24 healthy controls with a similar body mass index and age were enrolled in this study. Serum levels of IMA, CIMT (estimated radiologically), and polysomnographic parameters, were determined and interpreted. Serum IMA levels were significantly higher in individuals with OSA compared with the control group (p=0.0003). CIMT was significantly higher in the OSA group compared with the control group (0.88 +/- 0.26 mm vs 0.75 +/- 0.17 mm, p=0.005). The CIMT and serum IMA levels were positively correlated with the apnea-hypopnea index (r=0.35 and r=0.32, respectively), and with the oxygen desaturation index (r=0.34 and r=0.29, respectively) at baseline. Increased IMA levels and CIMT may be related to increased oxidative stress and risk of atherosclerosis in individuals with OSA.