title: Impaired glucose tolerance is normalized by treatment with the thiazolidinedione troglitazone.
abstract: OBJECTIVE
  The primary purpose of this study was to assess the effects of 12 weeks of treatment with either troglitazone, an investigational thiazolidinedione that acts as an insulin-action enhancer, or placebo in patients with impaired glucose tolerance (IGT).
  
  
  METHODS
  A total of 51 subjects with IGT between 24 and 77 years of age were enrolled in this multicenter, double-blind, placebo-controlled, parallel group study (troglitazone, 25 patients; placebo, 26 patients). Patients were randomly assigned to receive either 400 mg troglitazone (every morning [QAM]) or placebo (QAM). The main outcome measure was the oral glucose tolerance test (OGTT) assessing glucose, insulin, and C-peptide levels in the fasting state and every 30 min up to 2 h after ingesting the glucose load. Fasting serum levels of HbA1c, fructosamine, lipids, and blood pressure were also measured.
  
  
  RESULTS
  A total of 46 patients completed the study. The glucose, insulin, and C-peptide responses after a glucose load were significantly reduced at 6 and 12 weeks in the troglitazone treatment group. After 6 weeks of treatment, 75% (n = 18) of those taking troglitazone had improved to normal glucose tolerance, whereas only 38% (n = 9) of those of placebo showed improvement (P = 0.008). After 12 weeks of treatment, 80% (n = 16) of the troglitazone treatment group had normalized their glucose tolerance, while only 48% (n = 10) of those on placebo had converted to normal (P = 0.016). Fasting triglyceride levels in the troglitazone treatment group had decreased by 40 mg/dl (0.45 mmol/l) (P = 0.0016). Other lipid measurements, blood pressure, glycosylated hemoglobin, and fructosamine were normal at baseline for both treatment groups and remained normal throughout the study.
  
  
  CONCLUSIONS
  The glycemic response after a glucose load is statistically and clinically significantly improved for patients with IGT treated with troglitazone.
authors.affiliation: Parke-Davis Pharmaceutical Research Division, Warner-Lambert Company, Ann Arbor, Michigan 48105, USA.
authors.forename: T
authors.initials: T
authors.lastname: Antonucci
authors.forename: R
authors.initials: R
authors.lastname: Whitcomb
authors.forename: R
authors.initials: R
authors.lastname: McLain
authors.forename: D
authors.initials: D
authors.lastname: Lockwood
authors.forename: R M
authors.initials: RM
authors.lastname: Norris
mesh_terms: D000328:Adult; D000368:Aged; D001786:Blood Glucose / Q000032:analysis* / Q000187:drug effects / Q000378:metabolism; D002096:C-Peptide / Q000097:blood* / Q000187:drug effects / Q000378:metabolism; D002839:Chromans / Q000627:therapeutic use*; D004311:Double-Blind Method; D005006:Ethnicity; D018149:Glucose Intolerance / Q000188:drug therapy*; D005951:Glucose Tolerance Test; D006801:Humans; D007004:Hypoglycemic Agents / Q000627:therapeutic use*; D007328:Insulin / Q000097:blood* / Q000378:metabolism; D008875:Middle Aged; D011446:Prospective Studies; D013844:Thiazoles / Q000627:therapeutic use*; D045162:Thiazolidinediones; D013997:Time Factors; D014280:Triglycerides / Q000097:blood / Q000378:metabolism; D000077288:Troglitazone
chemical_list: D001786:Blood Glucose; D002096:C-Peptide; D002839:Chromans; D007004:Hypoglycemic Agents; D007328:Insulin; D013844:Thiazoles; D045162:Thiazolidinediones; D014280:Triglycerides; D000077288:Troglitazone