title: Diabetes mellitus and risk of pancreatic cancer: A meta-analysis of cohort studies.
abstract: BACKGROUND
  Diabetes mellitus (DM) is widely considered to be associated with risk of pancreatic cancer (PaC), however, whether DM is a cause or a consequence of PaC is still controversial. We examined this association by conducting a detailed meta-analysis of cohort studies.
  
  
  METHODS
  Studies were identified by searching Medline and Embase through November 30, 2010. Summary relative risks (RRs) with their corresponding 95% confidence intervals (CIs) were calculated using a random-effects model.
  
  
  RESULTS
  A total of thirty-five cohort studies were included in this meta-analysis. DM was associated with an increased risk of PaC (the summary RRs=1.94; 95% CI, 1.66-2.27), with significant evidence of heterogeneity among these studies (p<0.001, I²=93.6%). Subgroup analyses revealed that the increased risk of PaC was independent of geographic locations, sex, study design, alcohol consumption, body mass index (BMI) and smoking status. In addition, the relative risk of PaC was correlated negatively with the duration of DM, with the highest risk of PaC found among patients diagnosed within less than 1 year. There was no significant publication bias (p=0.136 for Egger's regression asymmetry test).
  
  
  CONCLUSIONS
  Findings from this meta-analysis strongly support that diabetes is associated with an increased risk of PaC in both males and females and that DM is both an early manifestation and an etiologic factor of pancreatic cancer.
authors: Department of Gastroenterology, Changhai Hospital of Second Military Medical University, Shanghai, China.
authors: Qiwen
authors: Q
authors: Ben
authors: Maojin
authors: M
authors: Xu
authors: Xiaoyan
authors: X
authors: Ning
authors: Jun
authors: J
authors: Liu
authors: Shangyou
authors: S
authors: Hong
authors: Wen
authors: W
authors: Huang
authors: Huagao
authors: H
authors: Zhang
authors: Zhaoshen
authors: Z
authors: Li
mesh_terms: D000328:Adult; D000368:Aged; D015331:Cohort Studies; D003924:Diabetes Mellitus, Type 2 / Q000150:complications / Q000453:epidemiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010190:Pancreatic Neoplasms / Q000453:epidemiology* / Q000209:etiology; D012307:Risk Factors