Urinary F-2-Isoprostanes as a Biomarker of Reduced Risk of Type 2 Diabetes

OBJECTIVE We have previously reported evidence of an inverse association between a urinary F-2-isoprostane and type 2 diabetes risk in a pilot case-control study nested within the Insulin Resistance Atherosclerosis Study (IRAS). Here, we report the results from the study extended to the entire IRAS cohort. RESEARCH DESIGN AND METHODS This prospective study included 138 incident type 2 diabetes case and 714 noncase subjects. Four F-2-isoprostanes (iPF2 alpha.-III; 2,3-dinor-iPF2 alpha-III; iPF2 alpha-VI; and 8,12-iso-iPF2 alpha-VI) were assayed in baseline urine samples using liquid chromatography tandem mass spectrometry. RESULTS Three F2-isoprostanes showed significant inverse associations with type 2 diabetes risk: the adjusted odds ratios were 0.52 (95% Cl 0.39-0.67), 0.56 (0.42-0.73), 0.62 (0.48-079), and 0.91 (0.72-1.12) for iPF2 alpha-III, 2,3-dinor-iPF2 alpha-III; iPF2 alpha-VI; and 8,12-iso-iPF2 alpha-VI, respectively. CONCLUSIONS Our findings indicate that urinary F-2-isoprostanes are inversely associated with type 2 diabetes risk beyond the traditional risk factors and may be useful in identifying highrisk populations.