Diabetes Q&A

Could an Oral Glucose Tolerance Test Predict Prediabetes Risk?




According to a recent study, the time to peak glucose measured during an oral glucose tolerance test (OGTT) could be an important predictor for determining prediabetes risk in adult patients.1

The study, presented at the Endocrine Society’s 99th annual meeting, examined the relationship between time to glucose peak and β-cell function in relation to insulin sensitivity to determine whether OGTT could predict prediabetes risk.
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In their multiethnic study, the researchers administered a standard OGTT to 123 adult participants who self-identified as healthy. Glucose, insulin, and C-peptide levels were measured at baseline and at 30, 60, 90, and 120 minutes after participants ingested sugar. Participants were divided according to glucose peak at 30 minutes vs glucose peak after 30 minutes. In addition, an insulin-modified frequently sampled intravenous glucose tolerance test was conducted 1 to 2 weeks after the standard OGTT.

A total of 76 participants (60%) had glucose peak occur after 30 minutes, and 43 participants (34%) were identified as having prediabetes. The researchers found that those with peak glucose after 30 minutes were 5 times more likely to have prediabetes compared with those with peak glucose at 30 minutes.

Peak glucose after 30 minutes was associated with older age, higher body mass index, lower β-cell function, lower acute insulin response to glucose, and a lower disposition index.

In addition, time to glucose peak was an independent predictor of disposition index, which was consistent in separate analyses of individuals with prediabetes and normal glucose tolerance.

Overall, the results of the study suggested that time to glucose peak during an OGTT was a strong indicator of β-cell function relative to insulin sensitivity and was independent of overall glycemia during the test.

“Our research may help clinicians and public health officials guide patients to better and more cost-effective decisions about risk for prediabetes,” the researchers said. “Further research is needed to assess whether this tool can be used to inform primary prevention guidelines for diabetes.”2

—Melissa Weiss


1. Chung ST, de la Cruz MG, Kasturi K, et al. Time to glucose peak during an oral glucose tolerance test identifies high prediabetes risk: results from a multiethnic study. Presented at: Endocrine Society’s 99th Annual Meeting; April 1-4, 2017; Orlando, FL. Accessed April 4, 2017.

2. New simple tool can help identify people at high risk for prediabetes [press release]. Orlando, FL: Endocrine Society; April 3, 2017. Accessed April 4, 2017.