THE ROLE OF OXIDATIVE STRESS IN ENDOTHELIAL DYSFUNCTION IN OSA PATIENTS

Endothelial dysfunction is highly prevalent among OSA patients. However, its pathogenetic mechanisms are not thoroughly studied. The aim of our study was to evaluate the role of oxidative stress in the pathogenesis of endothelial dysfunction among OSA patients and to compare it to healthy control subjects. We studied 98 consecutive patients, who were referred to the clinic for probable OSA. Patients underwent standard polysomnography. To assess oxidative stress, we measured urinary 8-iso-PGF2 alpha. Flow mediated brachial artery dilation (FMD) was determined to assess endothelial function. Patients with moderate-severe OSAS had higher urinary 8-iso-PGF2 alpha (0.021 pg/mu mo1/1 cre), compared to healthy subjects (0.017 pg/mu mo1/1 cre, p = 0.037). In contrast to metabolic syndrome urinary 8-isoprostanes were the only independent predictors of FMD (beta = -0.21, p < 0.048). In conclusion, the results of our study indicate that patients with OSAS have an increased oxidative stress, that is implicated in the pathogenesis of arterial dysfunction.