One-hour glucose during an oral glucose challenge prospectively predicts β-cell deterioration and prediabetes in obese Hispanic youth

Abstract

Objective: In adults, 1-h glucose during an oral glucose tolerance test (OGTT) predicts the development of type 2 diabetes independent of fasting and 2-h glucose concentrations. The purpose of the current investigation was to examine the utility of elevated 1-h glucose levels to prospectively predict deterioration in β-cell function and the development of prediabetes in high-risk youth.

Research design and methods: Obese Latino youth with a family history of type 2 diabetes (133 male and 100 female; age 11.1 ± 1.7 years) completed a baseline OGTT and were divided into two groups based upon a 1-h glucose threshold of 155 mg/dL (<155 mg/dL, n = 151, or ≥ 155 mg/dL, n = 82). Youth were followed annually for up to 8 years for assessment of glucose tolerance, body composition by dual-energy X-ray absorptiometry, and insulin sensitivity, insulin secretion, and the disposition index by the frequently sampled intravenous glucose tolerance test.

Results: Over time, the ≥ 155 mg/dL group exhibited a significantly greater decline in β-cell function compared with youth with a 1-h glucose <155 mg/dL (β = -327.8 ± 126.2, P = 0.01). Moreover, this decline was independent of fasting or 2-h glucose and body composition. When the data were restricted to only participants with normal glucose tolerance at baseline, a 1-h glucose ≥ 155 mg/dL was independently associated with a 2.5 times greater likelihood of developing prediabetes during follow-up (95% CI 1.6-4.1, P = 0.0001).

Conclusions: These data suggest that a 1-h glucose ≥ 155 mg/dL during an OGTT is an independent predictor of β-cell deterioration and progression to prediabetes among obese Latino youth.

Figure 1

Changes in DI over time in the <155 mg/dL and ≥155 mg/dL groups.