Aims: Serum uromodulin has recently emerged as promising biomarker for kidney function and was suggested to be associated with type 2 diabetes (T2D) in patients with coronary heart disease. Here, we analyzed the association of serum uromodulin with T2D in the population-based KORA F4/FF4 study.Methods: In 1119 participants of the KORA F4 study aged 62 to 81 years, serum uromodulin was measured, and the association of serum uromodulin with T2D was assessed using logistic and linear regression models stratified for sex. After a mean follow-up time of 6.5 years, 635 participants where re-evaluated. Glucose tolerance status was determined by oral glucose tolerance test at baseline and at the follow-up examination except in cases of known T2D.Results: Serum uromodulin was inversely associated with T2D in the crude analysis and after adjustment for age and body mass index in men (P < 0.001) and in women (P < 0.05). After further adjustment for estimated glomerular filtration rate, serum uromodulin was significantly inversely associated with T2D in men (P < 0.001) but not in women. Serum uromodulin was not associated with prediabetes after multivariate adjustment and did not predict T2D in men or in women after the follow-up time of 6.5 +/- 0.3 years.Conclusions: In participants of the KORA F4 study, serum uromodulin is independently associated with T2D in men but is not a predictor of future development of T2D.