Cigarette smokers are at higher risk of developing multiple sclerosis (MS), according to background information in the article. However, the effect of smoking on the progression of MS remains uncertain.
Brian C. Healy, Ph.D., of Brigham and Women's Hospital, Harvard Medical School and Massachusetts General Hospital, Boston, and colleagues studied 1,465 patients with MS who visited a referral center between February 2006 and August 2007. Participants had an average age of 42 and had MS for an average of 9.4 years. Their progression was assessed by clinical characteristics as well as by magnetic resonance imaging (MRI) over an average of 3.29 years.