Prediction of diabetes based on baseline metabolic characteristics in individuals at high risk

OBJECTIVE-Individuals with impaired glucose tolerance (IGT) are at high risk for developing type 2 diabetes mellitus (T2DM).We examined which characteristics at baseline predicted the development of T2DMversus maintenance of IGT or conversion to normal glucose tolerance. RESEARCH DESIGN AND METHODS-We studied 228 subjects at high risk with IGT who received treatment with placebo in ACTNOWand who underwent baseline anthropometric measures and oral glucose tolerance test (OGTT) at baseline and after a mean follow-up of 2.4 years. RESULTS-In a univariate analysis, 45 of 228 (19.7%) IGT individuals developed diabetes. After adjusting for age, sex, and center, increased fasting plasma glucose, 2-h plasma glucose, ΔG_0-120 during OGTT, HbA _1c, adipocyte insulin resistance index, ln fasting plasma insulin, and ln ΔI_0-120, as well as family history of diabetes and presence of metabolic syndrome, were associated with increased risk of diabetes. At baseline, higher insulin secretion (ln [ΔI_0-120/ ΔG_0-120]) during the OGTT was associated with decreased risk of diabetes. Higher β-cell function (insulin secretion/insulin resistance or disposition index; ln [ΔI_0-120/ΔG_0-120 × Matsuda index of insulin sensitivity]; odds ratio 0.11; P<0.0001)was the variablemost closely associated with reduced risk of diabetes. CONCLUSIONS-In a stepwise multiple-variable analysis, only HbA_1c and β-cell function (ln insulin secretion/insulin resistance index) predicted the development of diabetes (r = 0.49; P < 0.0001).