Arsenic exposure in relation to ischemic stroke the reasons for geographic and racial differences in stroke study

Academic Article


  • © 2017 American Heart Association, Inc. Background and Purpose-The purpose of this case-cohort study was to examine urinary arsenic levels in relation to incident ischemic stroke in the United States. Methods-We performed a case-cohort study nested within the REGARDS (REasons for Geographic and Racial Differences in Stroke) cohort. A subcohort (n=2486) of controls was randomly sampled within region-race-sex strata while all incident ischemic stroke cases from the full REGARDS cohort (n=671) were included. Baseline urinary arsenic was measured by inductively coupled plasma-mass spectrometry. Arsenic species, including urinary inorganic arsenic and its metabolites monomethylarsonic acid and dimethylarsinic acid, were measured in a random subset (n=199). Weighted Cox's proportional hazards models were used to calculate hazard ratios and 95% confidence intervals of ischemic stroke by arsenic and its species. Results-The average follow-up was 6.7 years. Although incident ischemic stroke showed no association with total arsenic or total inorganic arsenic, for each unit higher level of urinary monomethylarsonic acid on a log-scale, after adjustment for potential confounders, ischemic stroke risk increased ∼2-fold (hazard ratio=1.98; 95% confidence interval: 1.12- 3.50). Effect modification by age, race, sex, or geographic region was not evident. Conclusions-A metabolite of arsenic was positively associated with incident ischemic stroke in this case-cohort study of the US general population, a low-to-moderate exposure area. Overall, these findings suggest a potential role for arsenic methylation in the pathogenesis of stroke, having important implications for future cerebrovascular research.
  • Authors

    Published In

  • Stroke  Journal
  • Digital Object Identifier (doi)

    Author List

  • Tsinovoi CL; Xun P; McClure LA; Carioni VMO; Brockman JD; Cai J; Guallar E; Cushman M; Unverzagt FW; Howard VJ
  • Start Page

  • 19
  • End Page

  • 26
  • Volume

  • 49
  • Issue

  • 1