Glucose Response Curve and Type 2 Diabetes Risk in Latino Adolescents

OBJECTIVE-In adults, the shape of the glucose response during an oral glucose tolerance test (OGTT) prospectively and independently predicts type 2 diabetes. However, no reports have described the utility of this indicator in younger populations. The purpose of this study was to compare type 2 diabetes risk factors in Latino adolescents characterized by either a monophasic or biphasic glucose response during an OGTT. RESEARCH DESIGN AND METHODS-A total of 156 nondiabetic Latino adolescents completed a 2-h OGTT. Monophasic and biphasic groups were compared for the following type 2 diabetes risk factors: fasting and 2-h glucose, HbA(lc), glucose area under the curve (AUC), insulin sensitivity (Matsuda index), insulin secretion (insulinogenic index), and beta-cell function as measured by the disposition index (insulin sensitivity X insulin secretion). RESULTS-Of the participants, 107 youth were categorized as monophasic and 49 were biphasic. Compared with the monophasic group, participants with a biphasic response exhibited lower HbA(lc) (5.4 +/- 0.3 vs. 5.6 +/- 0.3%, P < 0.01) and lower glucose AUC (14,205 +/- 2,382 vs. 16,230 +/- 2,537 mg . dL(-1) . h(-1), P < 0.001) with higher insulin sensitivity (5.4 +/- 3.2 vs. 4.6 +/- 3.4, P <= 0.05), higher insulin secretion (2.1 +/- 1.3 vs. 1.8 +/- 1.3, P = 0.05), and better beta-cell function (10.3 +/- 7.8 vs. 6.0 +/- 3.6, P < 0.001). Differences persisted after adjusting for age, sex, and BMI. CONCLUSIONS-These data suggest that the glycemic response to an OGTT may differentiate risk for type 2 diabetes in youth. This response may be an early marker of type 2 diabetes risk among high-risk youth.