Background: Dexamethasone (dex) challenge was used historically to diagnose chemical diabetes. Here we determined its utility in predicting prediabetes in a biracial cohort.

Methods: We studied 190 euglycemic subjects with parental type 2 diabetes. After a baseline 75-gram OGTT, subjects ingested 2 mg dex at 10 PM and returned at 8AM for measurement of plasma cortisol and glucose. Subjects were followed quarterly for incident prediabetes for 5 years. Serial assessments included OGTT, insulin secretion (IVGTT), and insulin sensitivity (euglycemic clamp).

Results: Table 1 shows baseline characteristics and response to dex. Progressors to prediabetes had a higher glycemic response to dex than nonprogressors (<0.0001). In a regression model, post-dex fasting glucose level remained a significant predictor of Incident prediabetes after controlling for age, weight, waist, and baseline glucose (P<0.001). From ROC analysis, fasting plasma glucose ≥110 mg/dL after dex predicted incident prediabetes with 80% sensitivity and 60% specificity.

Conclusion: Glycemic response to 2mg dex predicts incident prediabetes and could be useful for stratification and selection of high-risk subjects for lifestyle intervention.

Table 1: Baseline demographic and glucoregulatory characteristics of subjects who developed prediabetes compared to those who remained normoglycemic.
Disclosure

E. Nyenwe: None. N.A. Umekwe: None. D.J. James: None. F. Ariganjoye: None. J.Y. Wan: None. S. Dagogo-Jack: Board Member; Self; Jana Care Inc. Consultant; Self; Janssen Pharmaceuticals, Inc., Merck & Co., Inc., Sanofi-Aventis. Research Support; Self; AstraZeneca, Novo Nordisk Inc. Stock/Shareholder; Self; Dance Biopharm Holdings Inc.

Funding

American Diabetes Association (7-07-MN-13 to S.D-J.); National Institutes of Health

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