title: Metformin use in patients with type 2 diabetes mellitus is associated with reduced risk of deep vein thrombosis: a non-randomized, pair-matched cohort study.
abstract: BACKGROUND
  Metformin, an insulin-sensitizer, may correct several physiologic abnormalities owing to insulin resistance in patients with type 2 diabetes mellitus (DM). The effects of metformin on venous thrombosis in patient with type 2 DM have not been reported. Our study strived to explore the relationship of metformin therapy and the subsequent development of deep vein thrombosis (DVT) using a nationwide, population-based database.
  
  
  METHODS
  From 1997 to 2003, we identified a study cohort consisting of patients with type 2 DM using metformin 7154 cases in the National Health Insurance Research Database. A control cohort without metformin, matched for age, sex, comorbidities, and medications was selected for comparison.
  
  
  RESULTS
  Of the 14945 patients (7167 patients with metformin vs. 7778 control), 60 (0.40%) patients developed DVT during a mean follow-up period of 3.74 years, including 16 (0.21%) from the cohort with metformin and 44 (0.56%) from the control group. Subjects with metformin experienced a 0.427 fold (95% confidence interval 0.240-0.758; P = 0.004) changes of risk reduction in development of DVT, which was independent of age, sex and co-morbidities. Kaplan-Meier analysis also revealed metformin therapy is associated with lower occurrence of DVT (log-rank test, P = 0.001).
  
  
  CONCLUSIONS
  Metformin may have protective effect in patients with type 2 DM for DVT.
authors.forename: Dai-Yin
authors.initials: DY
authors.lastname: Lu
authors.forename: Chin-Chou
authors.initials: CC
authors.lastname: Huang
authors.forename: Po-Hsun
authors.initials: PH
authors.lastname: Huang
authors.forename: Chia-Min
authors.initials: CM
authors.lastname: Chung
authors.forename: Shing-Jong
authors.initials: SJ
authors.lastname: Lin
authors.forename: Jaw-Wen
authors.initials: JW
authors.lastname: Chen
authors.forename: Wan-Leong
authors.initials: WL
authors.lastname: Chan
authors.affiliation: Division of Cardiology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan. hbleu@vghtpe.gov.tw.
authors.forename: Hsin-Bang
authors.initials: HB
authors.lastname: Leu
mesh_terms: D000368:Aged; D003924:Diabetes Mellitus, Type 2 / Q000188:drug therapy*; D005260:Female; D006801:Humans; D007004:Hypoglycemic Agents / Q000627:therapeutic use*; D053208:Kaplan-Meier Estimate; D008297:Male; D016555:Matched-Pair Analysis; D008687:Metformin / Q000627:therapeutic use*; D008875:Middle Aged; D012307:Risk Factors; D013624:Taiwan / Q000453:epidemiology; D020246:Venous Thrombosis / Q000453:epidemiology / Q000517:prevention & control*
chemical_list: D007004:Hypoglycemic Agents; D008687:Metformin