title: Smoking and disease progression in multiple sclerosis.
abstract: BACKGROUND
  Although cigarette smokers are at increased risk of developing multiple sclerosis (MS), the effect of smoking on the progression of MS remains uncertain.
  
  
  OBJECTIVE
  To establish the relationship between cigarette smoking and progression of MS using clinical and magnetic resonance imaging outcomes
  
  
  METHODS
  Cross-sectional survey and longitudinal follow-up for a mean of 3.29 years, ending January 15, 2008.
  
  
  METHODS
  Partners MS Center (Boston, Massachusetts), a referral center for patients with MS.
  
  
  METHODS
  Study participants included 1465 patients with clinically definite MS (25.1% men), with mean (range) age at baseline of 42.0 (16-75) years and disease duration of 9.4 (0-50.4) years. Seven hundred eighty patients (53.2%) were never-smokers, 428 (29.2%) were ex-smokers, and 257 (17.5%) were current smokers.
  
  
  METHODS
  Smoking groups were compared for baseline clinical and magnetic resonance imaging characteristics as well as progression and sustained progression on the Expanded Disability Status Scale at 2 and 5 years and time to disease conversion to secondary progressive MS. In addition, the rate of on-study change in the brain parenchymal fraction and T2 hyperintense lesion volume were compared.
  
  
  RESULTS
  Current smokers had significantly worse disease at baseline than never-smokers in terms of Expanded Disability Status Scale score (adjusted P < .001), Multiple Sclerosis Severity Score (adjusted P < .001), and brain parenchymal fraction (adjusted P = .004). In addition, current smokers were significantly more likely to have primary progressive MS (adjusted odds ratio, 2.41; 95% confidence interval, 1.09-5.34). At longitudinal analyses, MS in smokers progressed from relapsing-remitting to secondary progressive disease faster than in never-smokers (hazard ratio for current smokers vs never-smokers, 2.50; 95% confidence interval, 1.42-4.41). In addition, in smokers, the T2-weighted lesion volume increased faster (P = .02), and brain parenchymal fraction decreased faster (P = .02).
  
  
  CONCLUSIONS
  Our data suggest that cigarette smoke has an adverse influence on the progression of MS and accelerates conversion from a relapsing-remitting to a progressive course.
authors: Department of Neurology, Partners MS Center, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA.
authors: Brian C
authors: BC
authors: Healy
authors: Eman N
authors: EN
authors: Ali
authors: Charles R G
authors: CR
authors: Guttmann
authors: Tanuja
authors: T
authors: Chitnis
authors: Bonnie I
authors: BI
authors: Glanz
authors: Guy
authors: G
authors: Buckle
authors: Maria
authors: M
authors: Houtchens
authors: Lynn
authors: L
authors: Stazzone
authors: Jennifer
authors: J
authors: Moodie
authors: Annika M
authors: AM
authors: Berger
authors: Yang
authors: Y
authors: Duan
authors: Rohit
authors: R
authors: Bakshi
authors: Samia
authors: S
authors: Khoury
authors: Howard
authors: H
authors: Weiner
authors: Alberto
authors: A
authors: Ascherio
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D020520:Brain Infarction / Q000473:pathology; D003430:Cross-Sectional Studies; D004185:Disability Evaluation; D018450:Disease Progression; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008137:Longitudinal Studies; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000150:complications / Q000401:mortality / Q000473:pathology* / Q000523:psychology*; D012189:Retrospective Studies; D012307:Risk Factors; D012720:Severity of Illness Index; D012907:Smoking / Q000009:adverse effects* / Q000523:psychology*; D018709:Statistics, Nonparametric; D055815:Young Adult