Performance of a multi-marker diabetes risk score in the insulin resistance atherosclerosis study (IRAS), a multi-ethnic U.S. cohort

Abstract

Background

This study compares a previously developed Diabetes Risk Score (DRS) to commonly-used clinical tools for type 2 diabetes risk evaluation in the Insulin Resistance Atherosclerosis Study (IRAS) cohort, a multi-ethnic U.S. cohort. Available as a clinical test, the PreDx® DRS, uses fasting concentrations of adiponectin, C-reactive protein, ferritin, interleukin-2 receptor alpha, HbA1c, glucose and insulin, plus age and gender to predict 5-year risk of diabetes. It was developed in a Northern European population.

Methods

The DRS was measured in archived fasting plasma specimens from 722 non-diabetic IRAS participants, 17.6% of whom developed diabetes during 5.2 years median follow-up (IQR: 5.1-5.4 years). The study included non-Hispanic whites (41.8%), Hispanics (34.5%) and African Americans (23.7%). Performance of the algorithm was evaluated by Area under the Receiver Operating Characteristic Curve (AROC) and risk reclassification against other tools.

Results

DRS discriminates participants who developed diabetes from those who did not significantly better than fasting glucose (AROC = 0.763 vs. 0.710, p = 0.003). The DRS performed equally well in subpopulations defined by race/ethnicity or gender. The DRS provided a significant Net Reclassification Improvement 0.24 (p = 0.01) when comparing predefined low/moderate/high DRS categories to metabolic syndrome risk factor counting. DRS complemented the use of the oral glucose tolerance test by identifying high risk patients with impaired fasting glucose but normal glucose tolerance, 33% of whom converted.

Conclusions

Measuring the DRS of elevated-risk U.S. patients could help physicians decide which patients warrant more intensive intervention. The DRS performed equally well across the ethnic subpopulations present in this cohort. Copyright © 2012 John Wiley & Sons, Ltd.