title: Association of inorganic arsenic exposure with type 2 diabetes mellitus: a meta-analysis.
abstract: BACKGROUND
  The association of long-term effects of inorganic arsenic (iAs) exposure with type 2 diabetes mellitus (T2DM) risk remains controversial.
  
  
  METHODS
  A literature search was performed in PubMed, China National Knowledge Infrastructure and Web of Knowledge for relevant available articles published in English or Chinese from 1 January 1990 to 5 June 2013. Case-control, cohort or cross-sectional studies evaluating iAs and T2DM were included. The DerSimonian and Laird random effect model was adopted as the pooling method. Dose-response relationship was assessed by restricted cubic spline model and multivariate random-effect meta-regression.
  
  
  RESULTS
  Of the 569 articles identified through searching databases, 17 published articles with 2,243,745 participants for iAs in drinking water and 21 083 participants for total arsenic (tAs) in urine were included for this meta-analysis. The pooled relative risk with 95% CI of T2DM for the highest versus lowest category of iAs exposure level in drinking water was 1.75 (1.20 to 2.54). After removing three studies that had a strong effect on heterogeneity, the pooled relative risk was 1.23 (1.12 to 1.36). Dose-response analysis suggested T2DM risk increased by 13% (1.13 (1.00 to 1.27)) for every 100 µg/L increment of iAs in drinking water. Significant association of T2DM risk with tAs in urine was also found 1.28 (1.14 to 1.44).
  
  
  CONCLUSIONS
  This meta-analysis indicates that long-term iAs exposure might be positively associated with T2DM risk.
authors.affiliation: Department of Epidemiology and Health Statistics, The Medical College of Qingdao University, , Qingdao, Shandong, People's Republic of China.
authors.forename: Weijing
authors.initials: W
authors.lastname: Wang
authors.forename: Zhutian
authors.initials: Z
authors.lastname: Xie
authors.forename: Yan
authors.initials: Y
authors.lastname: Lin
authors.forename: Dongfeng
authors.initials: D
authors.lastname: Zhang
mesh_terms: D001151:Arsenic / Q000009:adverse effects* / Q000032:analysis / Q000652:urine; D016022:Case-Control Studies; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D003924:Diabetes Mellitus, Type 2 / Q000139:chemically induced / Q000453:epidemiology*; D004305:Dose-Response Relationship, Drug; D060766:Drinking Water / Q000009:adverse effects / Q000032:analysis / Q000737:chemistry*; D004781:Environmental Exposure; D006801:Humans; D012307:Risk Factors; D013223:Statistics as Topic
chemical_list: D060766:Drinking Water; D001151:Arsenic
keywords: EPIDEMIOLOGY; Environmental epidemiology; PUBLIC HEALTH; SYSTEMATIC REVIEWS; TOXICOLOGY