Aim and Objective:
In general, cigarette smoking is linked to increased risk of occurrence of MS and rate of progression. Extended disability status scale (EDSS) is used for measuring disability status of MS patients. Higher EDSS score indicates a worse neurological dysfunction In our study, we aimed to reveal the effect of smoking on disability progression in Turkish patients with MS.

Methods:
Patients were divided into two groups according to smoking status (smokers and non-smokers). Demographic characteristics and clinical parameters of disease progression including time to reach EDSS 3 and EDSS 6 were compared between both groups using chi-square, student's t-test, log-rank test, and ANOVA.

Results:
Overall, 280 smokers (108 males, 172 females) and 685 non-smokers (171 males, 514 females) were included in the study. There was no difference between the two groups in terms of gender, age at onset, the duration between first two relapses, and MS subtypes (p>0,05). As expected, women smoked less than men (p<0.001). Interestingly, as education level increased, there was a tendency to smoking (p=0.001). We found no difference in the time to reach EDSS 3 and EDSS 6 for smokers and non-smokers (log-rank test; p=0.48 and p=0.93).

Conclusions:
Our study suggests that, unlike general notion, cigarette smoking does not affect the rate of progression in MS patients negatively. The lack of effect of smoking in Turkish patients with MS suggests that the relationship between smoking and MS may be affected by complex genetic factors.