Cigarette Smoking in Multiple Sclerosis and Its Impact on the Disability

OBJECTIVE: We aimed to investigate the effect of smoking on multiple sclerosis (MS) development. METHODS: The data of 270 MS patients were collected retrospectively. The patients were classified according to disease severity and MS subtypes. Expanded Disability Status Scale (EDSS) and the MS types were statistically compared with smoking features. RESULTS: Sixty-seven percent of the patients were females and 33% were males. The mean age was 40.9 ± 10.73 years. The age at disease onset was 31.3 ± 9.9 and the disease duration was 9.5 ± 6.3 years. EDSS was < 5.0 in 76% of the patients and ≥ 5.5 in 24%. The rate of nonsmokers was 45.4%, while 19.1% were light smokers, and 35.5% were heavy smokers. There was no difference between smokers and nonsmokers according to EDSS and MS types (p= 0.19 and p= 0.55). According to subgroup analysis, EDSS was high in male smokers (p= 0.024). CONCLUSION: No relationship was found between the risk of MS development and smoking. The relevant literature generally favors a negative effect of smoking on MS; however, there are some reports with insignificant results, similar to ours. In our study, the only significant finding was the relationship between high EDSS and high smoking rate in male patients in the subgroup analysis. Additionally, the rate of smoking was nearly twice of the normal population among female MS patients. In the Turkish population, the rate of smoking is markedly higher in men than women. Additionally, male gender is regarded as an unfavorable prognostic factor in MS. Hence, the statistical significance we found may represent only the effect of gender, or smoking might exert an additional negative, albeit weak effect on disability status in MS. Our study revealed a neutral relationship between smoking and MS in our region in a limited patient population