The Effect of Smoking on Mitochondrial Biogenesis in Patients With Graves Ophthalmopathy

PURPOSE: To evaluate the effects of cigarette smoking on oxidative stress (OS) and mitochondrial biogenesis related parameters in patients Graves Ophthalmopathy (GO). METHODS: Patients with moderate-to-severe GO according to the European Group on Graves Orbitopathy (EUGOGO) criteria were prospectively enrolled in this study. Age- and sex-matched healthy volunteers who applied to outpatient clinic due to refractive problems consisted the control group. Participants were divided into 4 groups based on their diagnosis and smoking status: group 1 (n = 30) smoker GO patients, group 2 (n = 30) nonsmoker GO patients, group 3 (n = 30) smoker healthy controls, and group 4 (n = 30) nonsmoker healthy controls. In the sera, total antioxidant status, total oxidant status and OS index values, peroxisome proliferator-activated receptor-gamma coactivator 1-alpha, mitochondrial transcriptional factor A levels, and paraoxonase-1 enzyme activity were evaluated. RESULTS: Total oxidant status and OS index values were the highest in group 1 compared to other groups (p = 0.031, p = 0.042; respectively). There was no statistically significant difference in total antioxidant status and peroxisome proliferator-activated receptor-gamma coactivator 1alpha levels among the groups (p = 0.521, p = 0.388; respectively). Paraoxonase-1 enzyme activity was the lowest in group 1 and highest in group 4 (p = 0.024). The levels of mitochondrial transcriptional factor A was the lowest in group 1 compared to other groups (p = 0.012). CONCLUSIONS: Cigarette smoking in GO patients seems to be a risk factor that increases OS, and therefore, it may have an unfavorable impact on the mitochondrial biogenesis.