Smoking and Disease Progression in Multiple Sclerosis
Brian C. Healy, PhD; Eman N. Ali, MD; Charles R. G. Guttmann, MD; Tanuja Chitnis, MD; Bonnie I. Glanz, PhD; Guy Buckle, MD; Maria Houtchens, MD; Lynn Stazzone, MSN, NP; Jennifer Moodie, MD; Annika M. Berger, MD; Yang Duan, MD; Rohit Bakshi, MD; Samia Khoury, MD; Howard Weiner, MD; Alberto Ascherio, MD
Arch Neurol. 2009;66(7):858-864.
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
Design Cross-sectional survey and longitudinal follow-up for a mean of 3.29 years, ending January 15, 2008.
Setting Partners MS Center (Boston, Massachusetts), a referral center for patients with MS.
Patients 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.
Main Outcome Measures 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).
Conclusion 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.
Indeed, this field of investigation is expanding rapidly, further clarification of the possible association or dissociation between MS and CCSVI is likely forthcoming. Smoking is reported to be significantly associated with lower limb venous insufficiency. The mechanisms leading to harmful effects of tobacco on the venous system are still not elucidated.127 However, cigarette smoking is believed to be a major factor in hypoxia through carbon monoxide and NO fixation in hemoglobin.127,128 It has been hypothesized that the effect of hypoxia on the functional state of the endothelium can be the starting point of a cascade of events leading to disorganization of the vessel typical of venous pathologies such as varicose veins. Hypoxia activates the endothelial cells, resulting in the production of proinflammatory factors within the vessel wall, increased capillary permeability and local inflammatory changes.129 Endothelial basal lamina has been found thickened in heavy smokers and the thickening contained fibronectin.130 It has also been reported that heavy smokers have impaired release of endothelium-derived relaxing factor in response to bradykinin and calcium ionophore. This impairment may increase vasomotor tone and smooth muscle proliferation in veins.131 Even the implication of a developmental origin in venous anomalies seen in CCSVI132 does not exclude the possibility that smoking could contribute to the venous flow abnormalities. It can thus be speculated that smoking may be related to venous MS hypothesis through harmful effects of tobacco on the venous system and its hemodynamics.
Interrupted wrote:Guilty, it sounds so ridiculous but MS in a way made me start again after 2 years stopping many years ago. It's totally an anxiety and boredom thing.
This evening I have received the dates for my procedure in Katowice in 3 weeks, and so tomorrow it'll be me+e-cigarette+a very grumpy mood! lol
Still, I think getting the actual date has been the kick up the bumsicle that I need. Time to cut the 15 year habit for good. <- that face is pure determination!
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