title: Vildagliptin added to metformin on β-cell function after a euglycemic hyperinsulinemic and hyperglycemic clamp in type 2 diabetes patients.
abstract: BACKGROUND
  This study evaluated the effect of vildagliptin + metformin on glycemic control and β-cell function in type 2 diabetes patients.
  
  
  METHODS
  One hundred seventy-one type 2 diabetes patients, naive to antidiabetes therapy and with poor glycemic control, were instructed to take metformin for 8±2 months up to a mean dosage of 2,500±500 mg/day; then they were randomly assigned to add vildaglipin 50 mg twice a day or placebo for 12 months. We evaluated at 3, 6, 9, and 12 months: body mass index, glycemic control, fasting plasma insulin, homeostasis model assessment insulin resistance index (HOMA-IR), homeostasis model assessment β-cell function index (HOMA-β), fasting plasma proinsulin, proinsulin/fasting plasma insulin ratio, C-peptide, glucagon, adiponectin, and high-sensitivity C-reactive protein. Before and at 12 months after the addition of vildagliptin, patients underwent a combined euglycemic hyperinsulinemic and hyperglycemic clamp, with subsequent arginine stimulation, to assess insulin sensitivity and insulin secretion.
  
  
  RESULTS
  After 12 months of treatment, vildagliptin + metformin gave a better decrease of body weight, glycemic control, HOMA-IR, and glucagon and a better increase of HOMA-β compared with placebo + metformin. Regarding the measures of β-cell function, treatment-induced changes in M-value, first- and second-phase C-peptide response to glucose, and C-peptide response to arginine were significantly higher in the vildagliptin + metformin group compared with the placebo + metformin group.
  
  
  CONCLUSIONS
  The addition of vildagliptin to metformin gave a better improvement of glycemic control, insulin resistance, and β-cell function compared with metformin alone.
authors.affiliation: Department of Internal Medicine and Therapeutics, University of Pavia, Pavia, Italy. giuseppe.derosa@unipv.it
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Derosa
authors.forename: Pietro D
authors.initials: PD
authors.lastname: Ragonesi
authors.forename: Anna
authors.initials: A
authors.lastname: Carbone
authors.forename: Elena
authors.initials: E
authors.lastname: Fogari
authors.forename: Lucio
authors.initials: L
authors.lastname: Bianchi
authors.forename: Aldo
authors.initials: A
authors.lastname: Bonaventura
authors.forename: Davide
authors.initials: D
authors.lastname: Romano
authors.forename: Arrigo F G
authors.initials: AF
authors.lastname: Cicero
authors.forename: Pamela
authors.initials: P
authors.lastname: Maffioli
mesh_terms: D000218:Adamantane / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000494:pharmacology; D001786:Blood Glucose / Q000378:metabolism*; D015992:Body Mass Index; D002096:C-Peptide / Q000097:blood; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000188:drug therapy*; D004359:Drug Therapy, Combination; D005215:Fasting / Q000097:blood; D005260:Female; D015309:Glucose Clamp Technique / Q000379:methods*; D006801:Humans; D007004:Hypoglycemic Agents / Q000008:administration & dosage* / Q000494:pharmacology; D007328:Insulin / Q000378:metabolism*; D007333:Insulin Resistance; D000078790:Insulin Secretion; D050417:Insulin-Secreting Cells / Q000187:drug effects* / Q000378:metabolism; D008297:Male; D008687:Metformin / Q000008:administration & dosage* / Q000494:pharmacology; D008875:Middle Aged; D009570:Nitriles / Q000008:administration & dosage* / Q000494:pharmacology; D011759:Pyrrolidines / Q000008:administration & dosage* / Q000494:pharmacology; D000077597:Vildagliptin; D015431:Weight Loss / Q000187:drug effects
chemical_list: D001786:Blood Glucose; D002096:C-Peptide; D007004:Hypoglycemic Agents; D007328:Insulin; D009570:Nitriles; D011759:Pyrrolidines; D008687:Metformin; D000077597:Vildagliptin; D000218:Adamantane