Oral Disposition Index Predicts the Development of Future Diabetes Above and Beyond Fasting and 2-h Glucose Levels

• Published in: Diabetes care Vol. 32; no. 2; pp. 335 - 341
• Main Authors: Utzschneider, Kristina M, Prigeon, Ronald L, Faulenbach, Mirjam V, Tong, Jenny, Carr, Darcy B, Boyko, Edward J, Leonetti, Donna L, McNeely, Marguerite J, Fujimoto, Wilfred Y, Kahn, Steven E
• Format: Journal Article
• Language: English
• Published: United States American Diabetes Association 01.02.2009
• Subjects: blood; Blood Glucose; Blood Glucose - metabolism; body mass index; Cardiovascular and Metabolic Risk; Diabetes; Diabetes Mellitus; Diabetes Mellitus - blood; Diabetes Mellitus - epidemiology; epidemiology; Fasting; Feedback; Follow-Up Studies; glucose; glucose tolerance; Glucose Tolerance Test; Glucose Tolerance Test - methods; homeostasis; Humans; Hyperglycemia; Hyperglycemia - epidemiology; Insulin; Insulin - physiology; Insulin Resistance; Insulin-Secreting Cells; Insulin-Secreting Cells - metabolism; Insulin-Secreting Cells - physiology; Japanese Americans; Measurement errors; men; metabolism; methods; Minority & ethnic groups; physiology; Plasma; Predictive Value of Tests; Regression Analysis; Reproducibility of Results; secretion; Statistical methods; Time Factors; Variables; women
• ISSN: 0149-5992; 1935-5548; 1935-5548
• DOI: 10.2337/dc08-1478

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.