Oxidative and nitrosative stress in patients with ischemic stroke

Background: Oxidative and nitrosative stress is well believed to play a role in the pathogenesis of ischemic stroke. This study aims to evaluate the time course of oxidative and nitrosative stress in ischemic stroke. Methods: In total, 27 healthy individuals, 22 individuals with high risk of ischemic stroke due to hypertension and diabetes mellitus, and 20 patients with acute ischemic stroke hospitalized at the Neurology Department of the Kirikkale University School of Medicine were enrolled in the study. Venous blood was collected at admission (hour 0) and again at hours 24, 48, 72, and 96. Nitric oxide (NO), malondialdehyde (MDA), total oxidative stress (TOS), oxidative stress index (OSI), and total antioxidant status (TAS) were measured and compared among stroke patients and control groups. Results: Blood NO was significantly higher in the patient group at 0, 24, 48, and 72 h compared to the healthy and high-risk control groups, and lower at 96 h than at early times within the patient group (p<0.001). MDA was higher in patients than the healthy control group at all times. Conversely, TOS and OSI were significantly lower in the patient group than the healthy control group at 96 h and the high-risk control group at 72 and 96 h (p <0.05). There was a significant correlation between initial NO (0 h) and duration of hospitalization (r= 0.71; p= 0.0003). Conclusions: These findings suggest a substantial early increase in oxidative and nitrosative stress in ischemic stroke patients during the first 2 days post-admission. However, TOS was lower by days 3-4, likely due to pathological recovery and local/systemic defense systems. The correlation between elevated serum NO during the acute phase of stroke and duration of hospitalization suggests NO as a potentially valuable predictor of ensuing oxidative damage and clinical outcome.