title: Diabetes mellitus carries a risk of gastric cancer: a meta-analysis.
abstract: OBJECTIVE
  To investigate the association and quantify the relationship between diabetes mellitus (DM) and gastric cancer (GC) by an updated meta-analysis.
  
  
  METHODS
  The initial PubMed search identified 1233 publications. Studies not reporting GC or those not reporting actual number of GC were excluded. Twelve pertinent studies were retrieved from the PubMed database or from a manual search and considered for the meta-analysis. Pooled risk ratios and 95%CI were estimated by a random-effects model. Subgroup analysis was performed according to gender or geographical regions. Heterogeneity and publication bias were evaluated by I (2) and funnel plot analysis, respectively.
  
  
  RESULTS
  DM was significantly associated with GC with a RR of 1.41 (P = 0.006) (95%CI: 1.10-1.81). Subgroup analyses revealed that both sexes showed a significant association with GC, with a greater magnitude of risk in females (RR = 1.90; 95%CI: 1.27-2.85; P = 0.002) than in males (RR = 1.24; 95%CI: 1.08-1.43; P = 0.002). In addition, the link between DM and GC was significant in East Asian DM patients (RR = 1.77; 95%CI: 1.38-2.26; P < 0.00001) but not in Western DM patients (RR = 1.23; 95%CI: 0.90-1.68; P = 0.2). There was no evidence of publication bias, but the results indicated significant heterogeneity.
  
  
  CONCLUSIONS
  This updated meta-analysis has provided evidence of positive DM-GC associations. The limited information on potentially important clinical confounding factors in each study deserves further investigation.
authors.affiliation: Shouji Shimoyama, Gastrointestinal Unit, Settlement Clinic, Tokyo 120-0003, Japan.
authors.forename: Shouji
authors.initials: S
authors.lastname: Shimoyama
mesh_terms: D044466:Asian People; D016009:Chi-Square Distribution; D048909:Diabetes Complications / Q000453:epidemiology* / Q000208:ethnology; D003920:Diabetes Mellitus / Q000453:epidemiology* / Q000208:ethnology; D005260:Female; D006801:Humans; D008297:Male; D016017:Odds Ratio; D012307:Risk Factors; D012737:Sex Factors; D013274:Stomach Neoplasms / Q000453:epidemiology* / Q000208:ethnology; D044465:White People
keywords: Diabetes mellitus; Gastric cancer; Hyperglycemia; Hyperinsulinemia; Meta-analysis