Jalal Poorolajal1, Masoud Bahrami2, Manoochehr Karami3, Elham Hooshmand2. 1. Modeling of Noncommunicable Diseases Research Center, Department of Epidemiology, School of Public Health, Hamadan University of Medical Sciences, Hamadan, Iran. 2. Department of Epidemiology, School of Public Health, Hamadan University of Medical Sciences, Hamadan 651783869, Iran. 3. Social Determinants of Health Research Center (SDHRC) and Department of Epidemiology, School of Public Health, Hamadan University of Medical Sciences, Hamadan, Iran.
Abstract
Background: Despite our awareness of the significant effect of smoking on multiple sclerosis (MS), there was a serious lack of information about the effect of different types of smoking habit on MS as well as the dose-response relationship between smoking and MS, but this gap was addressed by this meta-analysis. Methods: Major electronic databases, including PubMed, Web of Science and Scopus were searched until July 2015. Epidemiological studies addressing the association between smoking and MS were enrolled. The heterogeneity across studies was investigated by Q-test and I2 statistic. The probability of publication bias was explored using Begg's and Egger's tests. The results were expressed as odds ratio (OR) with 95% confidence intervals (CI) using a random effects model. Results: We identified a total of 10 687 references and included 34 studies involving 623 852 participants. Compared with nonsmokers, the OR estimate of MS was 1.46 (1.33, 1.59) among ever smokers, 1.57 (1.34, 1.80) among current smokers, 1.36 (1.27, 1.46) among ex-smokers and 1.12 (0.87, 1.36) among passive smokers. In addition, analyzing the effect of cigarette pack-year on MS indicated that the OR estimate of MS was 1.34 (1.06, 1.61) for 1-5 cigarette pack-years, 1.56 (1.15, 1.97) for 6-10 cigarette pack-years, 1.74 (1.16, 2.33) for 11-15 cigarette pack-years and 1.46 (0.49, 2.43) for more than 15 cigarette pack-years. Conclusions: Smoking habits are significantly associated with MS, although the association is not very strong. However, there is a dose-response relationship between the smoking habits and MS.
Background: Despite our awareness of the significant effect of smoking on multiple sclerosis (MS), there was a serious lack of information about the effect of different types of smoking habit on MS as well as the dose-response relationship between smoking and MS, but this gap was addressed by this meta-analysis. Methods: Major electronic databases, including PubMed, Web of Science and Scopus were searched until July 2015. Epidemiological studies addressing the association between smoking and MS were enrolled. The heterogeneity across studies was investigated by Q-test and I2 statistic. The probability of publication bias was explored using Begg's and Egger's tests. The results were expressed as odds ratio (OR) with 95% confidence intervals (CI) using a random effects model. Results: We identified a total of 10 687 references and included 34 studies involving 623 852 participants. Compared with nonsmokers, the OR estimate of MS was 1.46 (1.33, 1.59) among ever smokers, 1.57 (1.34, 1.80) among current smokers, 1.36 (1.27, 1.46) among ex-smokers and 1.12 (0.87, 1.36) among passive smokers. In addition, analyzing the effect of cigarette pack-year on MS indicated that the OR estimate of MS was 1.34 (1.06, 1.61) for 1-5 cigarette pack-years, 1.56 (1.15, 1.97) for 6-10 cigarette pack-years, 1.74 (1.16, 2.33) for 11-15 cigarette pack-years and 1.46 (0.49, 2.43) for more than 15 cigarette pack-years. Conclusions: Smoking habits are significantly associated with MS, although the association is not very strong. However, there is a dose-response relationship between the smoking habits and MS.
Authors: Amin Ziaei; Amy M Lavery; Xiaorong Ma Shao; Cameron Adams; T Charles Casper; John Rose; Meghan Candee; Bianca Weinstock-Guttman; Greg Aaen; Yolanda Harris; Jennifer Graves; Leslie Benson; Mark Gorman; Mary Rensel; Soe Mar; Tim Lotze; Benjamin Greenberg; Tanuja Chitnis; Janace Hart; Amy T Waldman; Lisa F Barcellos; Emmanuelle Waubant Journal: Mult Scler Date: 2022-01-08 Impact factor: 5.855
Authors: Cecilia Wallin; Sabrina B Sholts; Nicklas Österlund; Jinghui Luo; Jüri Jarvet; Per M Roos; Leopold Ilag; Astrid Gräslund; Sebastian K T S Wärmländer Journal: Sci Rep Date: 2017-10-31 Impact factor: 4.379
Authors: Mattia Rosso; Dorlan J Kimbrough; Cindy T Gonzalez; Bonnie I Glanz; Brian C Healy; Maria Assunta Rocca; Massimo Filippi; Howard Weiner; Tanuja Chitnis Journal: Mult Scler J Exp Transl Clin Date: 2019-02-25
Authors: Emmanuelle Waubant; Robyn Lucas; Ellen Mowry; Jennifer Graves; Tomas Olsson; Lars Alfredsson; Annette Langer-Gould Journal: Ann Clin Transl Neurol Date: 2019-08-07 Impact factor: 4.511
Authors: Ruth E Mitchell; Kirsty Bates; Robyn E Wootton; Adil Harroud; J Brent Richards; George Davey Smith; Marcus R Munafò Journal: PLoS Biol Date: 2020-11-30 Impact factor: 8.029