Display Settings:

Format

Send to:

Choose Destination
See comment in PubMed Commons below
Arch Neurol. 2011 Feb;68(2):207-13. doi: 10.1001/archneurol.2010.367.

Smoking and risk of amyotrophic lateral sclerosis: a pooled analysis of 5 prospective cohorts.

Author information

  • 1Department of Nutrition, Harvard School of Public Health, 665 Huntington Ave, Boston, MA 02115, USA.

Abstract

BACKGROUND:

Cigarette smoking has been proposed as a risk factor for amyotrophic lateral sclerosis (ALS), but epidemiological studies supporting this hypothesis have been small and mostly retrospective.

OBJECTIVE:

To prospectively examine the relation between smoking and ALS in 5 well-established large cohorts.

DESIGN:

Five prospective cohorts with study-specific follow-up ranging from 7 to 28 years.

SETTING:

Academic research.

PATIENTS:

Participants in the Nurses' Health Study, the Health Professionals Follow-up Study, the Cancer Prevention Study II Nutrition Cohort, the Multiethnic Cohort, and the National Institutes of Health-AARP (formerly known as the American Association of Retired Persons) Diet and Health Study.

MAIN OUTCOME MEASURES:

Amyotrophic lateral sclerosis deaths identified through the National Death Index. In the Nurses' Health Study and the Health Professionals Follow-up Study, confirmed nonfatal incident ALS was also included.

RESULTS:

A total of 832 participants with ALS were documented among 562,804 men and 556,276 women. Smokers had a higher risk of ALS than never smokers, with age- and sex-adjusted relative risks of 1.44 (95% confidence interval, 1.23-1.68; P < .001) for former smokers and 1.42 (95% confidence interval, 1.07-1.88; P = .02) for current smokers. Although the risk of ALS was positively associated with pack-years smoked (P < .001), duration of smoking (9% increase for each 10 years of smoking, P = .006), and the number of cigarettes smoked per day (10% increase for each increment of 10 cigarettes smoked per day, P < .001), these associations did not persist when never smokers were excluded. However, among ever smokers, the risk of ALS increased as age at smoking initiation decreased (P = .03).

CONCLUSIONS:

Results of this large longitudinal study support the hypothesis that cigarette smoking increases the risk of ALS. The potential importance of age at smoking initiation and the lack of a dose response deserve further investigation.

PMID:
21320987
[PubMed - indexed for MEDLINE]
PMCID:
PMC3319086
Free PMC Article
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Icon for Silverchair Information Systems Icon for PubMed Central
    Loading ...
    Write to the Help Desk