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

To evaluate the effects of cigarette smoking on oxidative stress (OS) and mitochondrial biogenesis related parameters in patients Graves Ophthalmopathy (GO).

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-γ coactivator 1-α, mitochondrial transcriptional factor A levels, and paraoxonase-1 enzyme activity were evaluated.

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-γ coactivator 1α 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).

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.