title: Patterns of insulin concentration during the OGTT predict the risk of type 2 diabetes in Japanese Americans.
abstract: OBJECTIVE
  To examine whether the patterns of insulin concentration during the oral glucose tolerance test (OGTT) predict type 2 diabetes.
  
  
  METHODS
  We followed 400 nondiabetic Japanese Americans for 10-11 years. Insulin concentrations at 30, 60, and 120 min during a 2-h 75-g OGTT at baseline were used to derive the following possible patterns of insulin: pattern 1 (30-min peak, higher insulin level at 60 than at 120 min), pattern 2 (30-min peak, lower or equal level at 60 vs. 120 min), pattern 3 (60-min peak); pattern 4 (120-min peak, lower level at 30 than at 60 min), and pattern 5 (120-min peak, equal or higher level at 30 vs. 60 min). Insulin sensitivity was estimated by homeostasis model assessment of insulin resistance (HOMA-IR) and Matsuda index. Insulin secretion was estimated by the insulinogenic index (IGI) [Δinsulin/Δglucose (30-0 min)] and disposition index (IGI/HOMA-IR).
  
  
  RESULTS
  There were 86 incident cases of type 2 diabetes. The cumulative incidence was 3.2, 9.8, 15.4, 47.8, and 37.5% for patterns 1, 2, 3, 4, and 5, respectively. Compared with pattern 1, patterns 4 and 5, characterized by a lasting late insulin response, were associated with significantly less insulin sensitivity as measured by the Matsuda index and lower early insulin response by the disposition index. The multiple-adjusted odds ratios of type 2 diabetes were 12.55 (95% CI 4.79-32.89) for pattern 4 and 8.34 (2.38-29.27) for pattern 5 compared with patterns 1 and 2. This association was independent of insulin secretion and sensitivity.
  
  
  CONCLUSIONS
  The patterns of insulin concentration during an OGTT strongly predict the development of type 2 diabetes.
authors.affiliation: Veterans Affairs Puget Sound Health Care System, Seattle, WA, USA.
authors.forename: Tomoshige
authors.initials: T
authors.lastname: Hayashi
authors.forename: Edward J
authors.initials: EJ
authors.lastname: Boyko
authors.forename: Kyoko Kogawa
authors.initials: KK
authors.lastname: Sato
authors.forename: Marguerite J
authors.initials: MJ
authors.lastname: McNeely
authors.forename: Donna L
authors.initials: DL
authors.lastname: Leonetti
authors.forename: Steven E
authors.initials: SE
authors.lastname: Kahn
authors.forename: Wilfred Y
authors.initials: WY
authors.lastname: Fujimoto
mesh_terms: D001213:Asian; D003924:Diabetes Mellitus, Type 2 / Q000453:epidemiology* / Q000378:metabolism*; D005260:Female; D005951:Glucose Tolerance Test / Q000379:methods*; D006801:Humans; D007328:Insulin / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio
chemical_list: D007328:Insulin