Prediagnostic body size and risk of amyotrophic lateral sclerosis death in 10 studies

Amyotroph Lateral Scler Frontotemporal Degener. 2018 Aug;19(5-6):396-406. doi: 10.1080/21678421.2018.1452944. Epub 2018 Apr 16.


Objectives and methods: Using pooled multivariable-adjusted rate ratios (RR), we explored relationships between prediagnostic body-mass-index (BMI), waist-to-hip-ratio (WHR), and weight-gain during adulthood, and ALS in 419,894 women and 148,166 men from 10 community-based cohorts in USA, Europe, and Australia; 428 ALS deaths were documented in women and 204 in men.

Results: Higher mid-to-later adulthood BMI was associated with lower ALS mortality. For 5 kg/m2 increased BMI, the rate was 15% lower (95% confidence interval [CI]: 4-24%; p = 0.005). Although a clear linear trend was not evident for WHR at enrollment (p = 0.099) individuals in the highest cohort-specific quartile had 27% (95% CI: 0-47%; p = 0.053) lower ALS compared to those in the lowest. BMI in early adulthood did not predict ALS; fewer than 10% of participants had early adulthood BMI >25 kg/m2, limiting power. Weight-gain during adulthood was strongly associated with lower ALS; for an additional 1kg gain in weight/year, the RR = 0.43 (95% CI: 0.28-0.65; p < 0.001). Associations persisted when adjusted for diabetes at enrollment, restricted to never-smokers, and ALS deaths in the 5 years after enrollment were excluded (accounting for recent weight loss).

Conclusions: These findings confirm somewhat conflicting, underpowered evidence that adiposity is inversely associated with ALS. We newly demonstrate that weight-gain during adulthood is strongly predictive of lower ALS risk.

Keywords: Amyotrophic lateral sclerosis; body mass index; waist-to-hip ratio; weight gain.

Publication types

  • Multicenter Study
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Age Factors
  • Aged
  • Aged, 80 and over
  • Amyotrophic Lateral Sclerosis / epidemiology*
  • Amyotrophic Lateral Sclerosis / mortality*
  • Anthropometry
  • Body Mass Index*
  • Cohort Studies
  • Female
  • Humans
  • International Cooperation
  • Male
  • Middle Aged
  • Sex Factors
  • Young Adult