title: Oral anti-diabetic drugs for the prevention of Type 2 diabetes.
abstract: OBJECTIVE
  To determine the comparative efficacy of oral anti-diabetic drugs in preventing the development of Type 2 diabetes.
  
  
  METHODS
  A systematic literature search of MEDLINE, EMBASE and Cochrane CENTRAL was conducted for randomized controlled trials evaluating oral anti-diabetic drugs in patients at high risk for developing Type 2 diabetes. Mixed-treatment comparison meta-analysis methods were used to evaluate the relative risks and risk differences of developing Type 2 diabetes, along with associated 95% credible intervals.
  
  
  RESULTS
  Overall, 20 trials (n = 23 230 participants) were included. Upon mixed-treatment comparison meta-analysis, thiazolidinediones, alpha-glucosidase inhibitors and biguanides significantly reduced the relative risk of developing diabetes by 64, 40 and 27%, respectively, compared with control. Sulphonylureas and glinides showed no significant effect. Moreover, thiazolidinediones significantly reduced the relative risk of diabetes by 50% compared with biguanides and trended towards a 40% risk reduction vs. alpha-glucosidase inhibitors [relative risk 0.60 (95% credible intervals 0.34-1.02)]. None of the results were appreciably altered upon subgroup or sensitivity analyses. When evaluating risk differences compared with control, thiazolidinediones (-9%, number needed to treat = 11), alpha-glucosidase inhibitors (-7%, number needed to treat = 14) and biguanides (-7%, number needed to treat = 14) continued to show significant benefit.
  
  
  CONCLUSIONS
  Of the oral anti-diabetic drugs evaluated to prevent Type 2 diabetes, thiazolidinediones were associated with the greatest risk reduction compared with control and associated with greater risk reduction than biguanides. Alpha-glucosidase inhibitors and biguanides performed similarly, and better than control, while sulphonylureas and glinides provided no significant benefit.
authors.affiliation: Western University of Health Sciences College of Pharmacy, Pomona, CA, USA.
authors.forename: O J
authors.initials: OJ
authors.lastname: Phung
authors.forename: N A
authors.initials: NA
authors.lastname: Sood
authors.forename: B E
authors.initials: BE
authors.lastname: Sill
authors.forename: C I
authors.initials: CI
authors.lastname: Coleman
mesh_terms: D000284:Administration, Oral; D001645:Biguanides / Q000627:therapeutic use*; D003924:Diabetes Mellitus, Type 2 / Q000517:prevention & control*; D005260:Female; D006801:Humans; D007004:Hypoglycemic Agents / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D016032:Randomized Controlled Trials as Topic; D045162:Thiazolidinediones / Q000627:therapeutic use*; D000520:alpha-Glucosidases / Q000627:therapeutic use*
chemical_list: D001645:Biguanides; D007004:Hypoglycemic Agents; D045162:Thiazolidinediones; D000520:alpha-Glucosidases