RT Journal Article SR Electronic T1 Oral Disposition Index Predicts the Development of Future Diabetes Above and Beyond Fasting and 2-h Glucose Levels JF Diabetes Care JO Diabetes Care FD American Diabetes Association SP 335 OP 341 DO 10.2337/dc08-1478 VO 32 IS 2 A1 Utzschneider, Kristina M. A1 Prigeon, Ronald L. A1 Faulenbach, Mirjam V. A1 Tong, Jenny A1 Carr, Darcy B. A1 Boyko, Edward J. A1 Leonetti, Donna L. A1 McNeely, Marguerite J. A1 Fujimoto, Wilfred Y. A1 Kahn, Steven E. YR 2009 UL http://care.diabetesjournals.org/content/32/2/335.abstract AB OBJECTIVE—We sought to determine whether an oral disposition index (DIO) predicts the development of diabetes over a 10-year period. First, we assessed the validity of the DIO by demonstrating that a hyperbolic relationship exists between oral indexes of insulin sensitivity and β-cell function. RESEARCH DESIGN AND METHODS—A total of 613 Japanese-American subjects (322 men and 291 women) underwent a 75-g oral glucose tolerance test (OGTT) at baseline, 5 years, and 10 years. Insulin sensitivity was estimated as 1/fasting insulin or homeostasis model assessment of insulin sensitivity (HOMA-S). Insulin response was estimated as the change in insulin divided by change in glucose from 0 to 30 min (ΔI0–30/ΔG0–30). RESULTS—ΔI0–30/ΔG0–30 demonstrated a curvilinear relationship with 1/fasting insulin and HOMA-S with a left and downward shift as glucose tolerance deteriorated. The confidence limits for the slope of the loge-transformed estimates included −1 for ΔI0–30/ΔG0–30 versus 1/fasting insulin for all glucose tolerance groups, consistent with a hyperbolic relationship. When HOMA-S was used as the insulin sensitivity measure, the confidence limits for the slope included −1 only for subjects with normal glucose tolerance (NGT) or impaired fasting glucose (IFG)/impaired glucose tolerance (IGT) but not diabetes. On the basis of this hyperbolic relationship, the product of ΔI0–30/ΔG0–30 and 1/fasting insulin was calculated (DIO) and decreased from NGT to IFG/IGT to diabetes (P < 0.001). Among nondiabetic subjects at baseline, baseline DIO predicted cumulative diabetes at 10 years (P < 0.001) independent of age, sex, BMI, family history of diabetes, and baseline fasting and 2-h glucose concentrations. CONCLUSIONS—The DIO provides a measure of β-cell function adjusted for insulin sensitivity and is predictive of development of diabetes over 10 years.