PURPOSE AND METHODS: To estimate the effect of exposure to smoking on the risk for multiple sclerosis (MS), we analyzed nicotine metabolite (cotinine) levels in biobank samples from 109 MS cases and 218 matched referents.

RESULTS: Elevated cotinine levels, even modest elevations, were associated with an increased risk for MS (all other categories versus lowest: OR = 2.9; 95% CI: 1.3-6.3). A similar but non-significant risk increase was observed also in the small subset of individuals with samples collected before the onset of MS (all other categories versus lowest: OR = 2.4; 95% CI: 0.26-21). Elevated cotinine was associated with an increased risk for MS predominantly in women (all other categories versus lowest category: OR = 3.9; 95% CI: 1.3-12), whereas the risk increase in men was smaller and non-significant..........

For the full abstract please go to MSRC: MS Research News : Environmental Factors And MS Research - http://www.msrc.co.uk/index.cfm?fuseaction=show&pageid=1850