Smoking, alcohol consumption, and the risk of amyotrophic lateral sclerosis: a population-based study

Am J Epidemiol. 2012 Aug 1;176(3):233-9. doi: 10.1093/aje/kws015. Epub 2012 Jul 11.


Smoking has been posited as a possible risk factor for amyotrophic lateral sclerosis (ALS), but large population-based studies of patients with incident disease are still needed. The authors performed a population-based case-control study in the Netherlands between 2006 and 2009, including 494 patients with incident ALS and 1,599 controls. To prove the relevance of population-based incidence cohorts in case-control studies, the authors compared results with those from cohorts including patients with prevalent ALS and referral patients. Subjects were sent a questionnaire. Multivariate analyses showed an increased risk of ALS among current smokers (odds ratio = 1.38, 95% confidence interval (CI): 1.02, 1.88) in the incident patient group only. Cox regression models showed that current smoking was also independently associated with shorter survival (hazard ratio = 1.51, 95% CI: 1.07, 2.15), explaining the lack of association in the prevalent and referral patient groups. Current alcohol consumption was associated with a reduced risk of ALS (incident patient group: odds ratio = 0.52, 95% CI: 0.40, 0.75). These findings indicate that current smoking is associated with an increased risk of ALS, as well as a worse prognosis, and alcohol consumption is associated with a reduced risk of ALS, further corroborating the role of lifestyle factors in the pathogenesis of ALS. The importance of population-based incident patient cohorts in identifying risk factors is highlighted by this study.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Alcohol Drinking / adverse effects*
  • Alcohol Drinking / epidemiology
  • Amyotrophic Lateral Sclerosis / epidemiology
  • Amyotrophic Lateral Sclerosis / etiology*
  • Amyotrophic Lateral Sclerosis / mortality
  • Case-Control Studies
  • Female
  • Humans
  • Male
  • Middle Aged
  • Multivariate Analysis
  • Netherlands / epidemiology
  • Proportional Hazards Models
  • Risk Factors
  • Sex Factors
  • Smoking / adverse effects*
  • Smoking / epidemiology
  • Surveys and Questionnaires
  • Survival Analysis
  • Young Adult