title: Comparative effectiveness of early versus delayed metformin in the treatment of type 2 diabetes.
abstract: OBJECTIVE
  The purpose of this study was to evaluate the effectiveness of early versus delayed initiation of metformin in type 2 diabetes.
  
  
  METHODS
  We identified 2925 new users of metformin with type 2 diabetes between 2005 and 2012 in the electronic health records of an integrated health system in Northern California. Patients were matched 1:1 on the propensity for receiving early treatment (defined as ≤6 months from first evidence of diabetes). We evaluated the effectiveness of early versus delayed metformin treatment on intermediate clinical outcomes indicated by changes in hemoglobin A1c (HbA1c) and body mass index (BMI), as well as the incidence of therapy intensification (addition or substitution of a second antihyperglycemic agent).
  
  
  RESULTS
  A total of 2144 propensity-score matched patients were included in the early or delayed treatment group (n=1072, in each). Early treatment was associated with significantly larger decreases in HbA1c (-0.36%; 95% confidence intervals [CI]: -0.44 to -0.27%; P<0.001) and BMI (-0.46 kg/m(2); 95% CI: -0.64 to -0.29 kg/m(2); P<0.001) relative to delayed treatment. Patients receiving early treatment also had a greater likelihood of attaining an HbA1c<7% (<53 mmol/mol) (odds ratio: 2.00; 95% CI: 1.63-2.45; P<0.001) and a reduced risk of therapy intensification (hazard ratio: 0.72; 95% CI: 0.61-0.85; P<0.001).
  
  
  CONCLUSIONS
  Treatment with metformin earlier in the course of type 2 diabetes is associated with better glycemic control, more pronounced weight reduction, and a lower risk for therapy intensification than delayed treatment. Antihyperglycemic therapy should be initiated early after diagnosis to achieve optimal outcomes.
authors: Palo Alto Medical Foundation Research Institute, Palo Alto, CA 94301, United States. Electronic address: romanellir@pamfri.org.
authors: Robert J
authors: RJ
authors: Romanelli
authors: Palo Alto Medical Foundation Research Institute, Palo Alto, CA 94301, United States.
authors: Sukyung
authors: S
authors: Chung
authors: Palo Alto Medical Foundation Research Institute, Palo Alto, CA 94301, United States.
authors: Jia
authors: J
authors: Pu
authors: Palo Alto Medical Foundation Research Institute, Palo Alto, CA 94301, United States.
authors: Vani
authors: V
authors: Nimbal
authors: Palo Alto Medical Foundation Research Institute, Palo Alto, CA 94301, United States.
authors: Beinan
authors: B
authors: Zhao
authors: Palo Alto Medical Foundation Research Institute, Palo Alto, CA 94301, United States; Stanford University School of Medicine, Stanford, CA 94305, United States.
authors: Latha
authors: L
authors: Palaniappan
mesh_terms: D001786:Blood Glucose / Q000378:metabolism; D015992:Body Mass Index; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000188:drug therapy*; D005260:Female; D005500:Follow-Up Studies; D006442:Glycated Hemoglobin / Q000378:metabolism; D006801:Humans; D007004:Hypoglycemic Agents / Q000627:therapeutic use; D008297:Male; D008687:Metformin / Q000627:therapeutic use*; D008875:Middle Aged; D012189:Retrospective Studies; D013997:Time Factors
chemical_list: D001786:Blood Glucose; D006442:Glycated Hemoglobin; D007004:Hypoglycemic Agents; D008687:Metformin
keywords: Metformin; Pharmacotherapy; Type 2 diabetes