title: Efficacy and safety of the dipeptidyl peptidase-4 inhibitor sitagliptin added to ongoing metformin therapy in patients with type 2 diabetes inadequately controlled with metformin alone.
abstract: OBJECTIVE
  The efficacy and safety of the dipeptidyl peptidase-4 inhibitor, sitagliptin, added to ongoing metformin therapy, were assessed in patients with type 2 diabetes who had inadequate glycemic control (HbA(1c) [A1C] >or=7 and <or=10%) with metformin alone.
  
  
  METHODS
  After a screening diet/exercise run-in period, a metformin dose titration/stabilization period, and a 2-week, single-blind, placebo run-in period, 701 patients, aged 19-78 years, with mild to moderate hyperglycemia (mean A1C 8.0%) receiving ongoing metformin (>or=1,500 mg/day) were randomly assigned to receive the addition of placebo or sitagliptin 100 mg once-daily in a 1:2 ratio for 24 weeks. Patients exceeding specific glycemic limits were provided rescue therapy (pioglitazone) until the end of the study. The efficacy analyses were based on an all-patients-treated population using an ANCOVA and excluded data obtained after glycemic rescue.
  
  
  RESULTS
  At week 24, sitagliptin treatment led to significant reductions compared with placebo in A1C (-0.65%), fasting plasma glucose, and 2-h postmeal glucose. Fasting insulin, fasting C-peptide, fasting proinsulin-to-insulin ratio, postmeal insulin and C-peptide areas under the curve (AUCs), postmeal insulin AUC-to-glucose AUC ratio, homeostasis model assessment of beta-cell function, and quantitative insulin sensitivity check index were significantly improved with sitagliptin relative to placebo. A significantly greater proportion of patients achieved an A1C <7% with sitagliptin (47.0%) than with placebo (18.3%). There was no increased risk of hypoglycemia or gastrointestinal adverse experiences with sitagliptin compared with placebo. Body weight decreased similarly with sitagliptin and placebo.
  
  
  CONCLUSIONS
  Sitagliptin 100 mg once-daily added to ongoing metformin therapy was efficacious and well tolerated in patients with type 2 diabetes who had inadequate glycemic control with metformin alone.
authors.affiliation: Center Hospitalier Universitaire de Nantes, France.
authors.forename: Bernard
authors.initials: B
authors.lastname: Charbonnel
authors.forename: Avraham
authors.initials: A
authors.lastname: Karasik
authors.forename: Ji
authors.initials: J
authors.lastname: Liu
authors.forename: Mei
authors.initials: M
authors.lastname: Wu
authors.forename: Gary
authors.initials: G
authors.lastname: Meininger
mesh_terms: D058892:Adenosine Deaminase Inhibitors; D000293:Adolescent; D000328:Adult; D000368:Aged; D001786:Blood Glucose / Q000187:drug effects / Q000378:metabolism; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000188:drug therapy*; D018819:Dipeptidyl Peptidase 4; D054873:Dipeptidyl-Peptidase IV Inhibitors; D004359:Drug Therapy, Combination; D005260:Female; D006442:Glycated Hemoglobin / Q000378:metabolism; D006023:Glycoproteins / Q000037:antagonists & inhibitors*; D006801:Humans; D007004:Hypoglycemic Agents / Q000627:therapeutic use*; D007328:Insulin / Q000097:blood; D008297:Male; D008687:Metformin / Q000627:therapeutic use*; D008875:Middle Aged; D010919:Placebos; D011384:Proinsulin / Q000097:blood; D011480:Protease Inhibitors / Q000627:therapeutic use*; D011719:Pyrazines / Q000627:therapeutic use*; D016037:Single-Blind Method; D000068900:Sitagliptin Phosphate; D014230:Triazoles / Q000627:therapeutic use*
chemical_list: D058892:Adenosine Deaminase Inhibitors; D001786:Blood Glucose; D018819:Dipeptidyl Peptidase 4; D054873:Dipeptidyl-Peptidase IV Inhibitors; D006442:Glycated Hemoglobin; D006023:Glycoproteins; D007004:Hypoglycemic Agents; D007328:Insulin; D008687:Metformin; D010919:Placebos; D011384:Proinsulin; D011480:Protease Inhibitors; D011719:Pyrazines; D000068900:Sitagliptin Phosphate; D014230:Triazoles; C042807:DPP4 protein, human