Diabetes Risk Index (DRI)

The Diabetes Risk Index (DRI) is a nuclear magnetic resonance spectroscopy (NMR)-derived multimarker score (values 1-100) that predicts a patient's risk of developing type 2 diabetes mellitus (T2D) independent of glycemic status. DRI derives its performance from the weighted addition of the Lipoprotein Insulin Resistance Index (LP-IR) scores with simultaneously-measured levels of branched-chain amino acids (BCAA).^1-7

LP-IR is a marker of insulin resistance, and as such the LP-IR score predicts a patient's likelihood of future development of T2D.^1-4 LP-IR is a multimarker index (values 0-100) based on the concentrations of particular lipoprotein subclasses [very large and large triglyceride-rich lipoprotein particles (VLL-TRLP), small low density lipoprotein particles (S-LDLP), large high density lipoprotein particles (L-HDLP), and mean TRL, LDL, and HDL particle sizes (TRLZ, LDLZ, HDLZ)]. The medical decision limits established for LPIR are <50 (low), 50-80 (intermediate), and >80 (high) with these cutpoints corresponding to the 25th and 75th percentiles in a normal population. DRI builds on the effective insulin resistance assessment by LP-IR and adds the measurement of BCAA. Similar to LP-IR, BCAA have also been shown to predict incident T2DM.^5,6 The analytes contributing to DRI are measured by mathematical deconvolution of the methyl signal region of the plasma/serum NMR spectrum. This algorithm is different from the NMR LipoProfile test in that the methyl region is extended downfield to include signals from the BCAA (valine and leucine).

For clinical use, DRI can be divided into three groups, corresponding to a low, intermediate, and high risk of developing T2D, with cutpoints corresponding closely to the 40th and 80th percentile values in the Multi-Ethnic Study of Atherosclerosis (MESA) reference population, using gender-specific cutpoints. Therefore, the low DRI category would include men and women with DRI scores less than 50 and 40, respectively. The intermediate DRI category would include men with DRI 50-65 and women with DRI 40-55. The high DRI group would consist of men and women with DRI >65 and >55, respectively.