The association of oxidative stress with central obesity in obstructive sleep apnea

The purpose of this paper is to evaluate concentrations of multiple oxidative stress and antioxidant status markers in patients with obstructive sleep apnea (OSA) and normal controls of comparable obesity. A total of 73 male subjects, recruited from a sleep clinic or advertisements, were enrolled in this study. All subjects underwent overnight polysomnography. The subjects were divided into normal control (n = 20), mild to moderate OSA (n = 31), and severe OSA (n = 22) with no difference in obesity. Blood was withdrawn from subjects, and markers of oxidative stress and antioxidant status, and parameters of glucose metabolism were assessed. There was no significant difference in either oxidative stress or antioxidant status markers among the three groups. There was no significant correlation between the oxidative stress markers and the OSA variables. However, there were correlations between waist-to-hip ratio (WHR)-oxidized low-density lipoprotein cholesterol (oxLDL) (r = 0.424), WHR-glutathione peroxidase (GPX) (r = 0.318), WHR-total antioxidant status (TAS) (r = -0.317), and WHR-superoxide dismutase (SOD) (r = -0.338). In multiple regression analysis, WHR was a significant independent variable of oxLDL, GPX, TAS, and SOD. The oxidative stress in OSA was related to central obesity rather than intermittent hypoxia or respiratory disturbances. To control cardiovascular complications in OSA, weight reduction should be a component in the treatment strategy.