Smoking, early menopause and multiple sclerosis disease course.

Smoking is associated with an increased risk of multiple sclerosis (MS), and smoking and early menopause are related to poor outcomes in MS. Smoking is also associated with early menopause. To explore this intricate relationship between smoking status, age at menopause and disease course in MS, 137 women with MS and 396 age-matched controls were included in this case-control study. Age at menopause (median 49.0 vs. 50.0 years;  = 0.79) and smoking status (40.3% vs. 47.6%;  = 0.15) were similar among MS and control women. Relapsing MS onset was earlier in ever-smoker women with early menopause compared to the rest of the women (median 30.4 vs. 37.0 years;  = 0.02) and also compared to ever-smoker women with normal age at menopause (median 30.4 vs. 41.0 years;  = 0.008) and never-smoker women with early menopause (median 30.4 vs. 41.5 years;  = 0.004). Progressive MS onset was also earlier in ever-smoker women with early menopause compared to ever-smoker women with normal age at menopause (median 41.1 vs. 49.4 years;  = 0.05) and never-smoker women with early menopause (median 41.1 vs. 50.1 years;  = 0.12). Our results suggest that smoking and menopause associate with MS disease course, including the onset of relapsing and progressive MS in women.