A study of nitrotyrosine levels in obsructive sleep apnea syndrome

OSAS is characterized by recurrent upper airway occlusion that is often resulting in oxygen desaturation and sleep division. Episodes of hypoxia-reoxygenation in OSAS patients, is preparing atherosclerosis through the formation of reactive oxygen and nitrogen species. The increase in oxidative stress, even if there is any cardiovascular risk factor in patients with OSAS, may cause endothelial dysfunction which may increase cardiovascular morbidity. The studies supports that OSA also increase the oxidative stress. Produced free radicals influenced through available nitric oxide (NO) level may increase these harmful effects. Nitric oxide, reacts with the superoxide radicals, contributes to the formation of peroxynitrite which is toxic to cells and reacts with lipid and protein disrupts the vascular function. Nitro tyrosine is an oxidation product which is formed by peroxynitrite that reacts with tyrosine residue of protein. In our study we aimed to examine the changes total NO levels in OSAS patients. In total 109 patients and 24 healthy controls in the measurements, although not statistically significant, there is an increase in nitro tyrosine levels and a decrease in total NO levels in patients compared with controls. In our study, we have also examined impact of the factors such as age, gender, obesity and smoking on the parameters. We observe a negative effect of body mass index and smoking on the parameters. Based on the results, we can discussed by considering that protein is less sensitive to free radical damage ,slightly elevated nitro tyrosine values due to oxidative stress in patients with OSAS could be indicator of protein damage.