Aim: To explore the putative association of new-onset diabetes and the soluble urokinase plasminogen activator receptor (suPAR), which is a new and stable plasma marker of immune function and low-grade inflammation. This association has been previously suggested by using the less sensitive International Classification of Disease system to detect incident diabetes in the Danish MONICA 10 cohort. Methods: The Danish National Diabetes Register enabled more accurate identification of incident diabetes during a median follow-up of 13.8 years in the Danish MONICA 10 cohort (n = 2353 generally healthy individuals). The soluble urokinase plasminogen activator receptor was measured by the ELISA method. To fulfil model assumptions, outcome analyses were stratified by age, and further by smoking, owing to the interaction between the soluble urokinase plasminogen activator receptor and smoking on new-onset diabetes (P