Dipeptidyl peptidase IV and incident diabetes: the Atherosclerosis Risk in Communities (ARIC) study.

OBJECTIVE: Dipeptidyl peptidase IV (DPP-IV) is not only important in beta-cell function but also has proinflammatory actions. We aimed to investigate whether it could act as a link between low-grade chronic inflammation and diabetes. RESEARCH DESIGN AND METHODS: Using a case-cohort design, we followed 546 middle-aged individuals who developed diabetes and 538 who did not over approximately 9 years within the Atherosclerosis Risk in Communities study. RESULTS: In weighted analyses, the correlation between DPP-IV levels and anthropometric, inflammatory, or metabolic variables was minimal (Spearman correlations <0.11). Those who developed diabetes had mean DPP-IV values similar to those who did not (P = 0.18). Individuals in the highest quartile of DPP-IV were not at greater risk of diabetes (hazard ratio 0.88 [95% CI 0.62-1.24]) in Cox proportional hazards models adjusting for age, sex, race, study center, and multiple additional diabetes risk factors. CONCLUSIONS: Fasting DPP-IV levels do not appear to predict incident diabetes.