Excess body weight and incidence of stroke: meta-analysis of prospective studies with 2 million participants

Stroke. 2010 May;41(5):e418-26. doi: 10.1161/STROKEAHA.109.576967. Epub 2010 Mar 18.

Abstract

Background and purpose: A systematic review of the prospective studies addressing the relationship of overweight and obesity to major stroke subtypes is lacking. We evaluated the occurrence of a graded association between overweight, obesity, and incidence of ischemic and hemorrhagic stroke by a meta-analysis of cohort studies.

Methods: A search of online databases and relevant reviews was performed. Inclusion criteria were original article in English, prospective study design, follow-up > or = 4 years, indication of number of subjects exposed, and number of events across body mass index categories. Crude unadjusted relative risk (RR) and 95% CI were calculated for each study for overweight or obese compared with normal-weight categories. Log-transformed values and SE were used to calculate the pooled RR with random effects models; publication bias was checked. Additional analyses were performed using the multivariate estimates of risk reported in the individual studies.

Results: Twenty-five studies were included, with 2 274 961 participants and 30 757 events. RR for ischemic stroke was 1.22 (95% CI, 1.05-1.41) for overweight and 1.64 (95% CI, 1.36-1.99) for obesity, whereas RR for hemorrhagic stroke was 1.01 (95% CI, 0.88-1.17) and 1.24 (95% CI, 0.99-1.54), respectively. Subgroup and meta-regression analyses ruled out gender, population average age, body mass index and blood pressure, year of recruitment, year of study publication, and length of follow-up as significant sources of heterogeneity. The additional analyses relying on the published multivariate estimates of risk provided qualitatively similar results.

Conclusions: Overweight and obesity are associated with progressively increasing risk of ischemic stroke, at least in part, independently from age, lifestyle, and other cardiovascular risk factors.

Publication types

  • Comparative Study
  • Meta-Analysis
  • Research Support, Non-U.S. Gov't
  • Review
  • Systematic Review

MeSH terms

  • Body Weight / physiology
  • Cohort Studies
  • Humans
  • Incidence
  • Obesity / complications
  • Obesity / epidemiology
  • Obesity / physiopathology
  • Overweight / complications*
  • Overweight / epidemiology*
  • Overweight / physiopathology
  • Prospective Studies
  • Risk Factors
  • Stroke / epidemiology*
  • Stroke / etiology*
  • Stroke / physiopathology