To test the hypothesis that the recently reported type 2 diabetes-associated variants in KCNQ1 have an effect on insulin release, we investigated rs2283228, rs2237892, rs2237895, and rs2237897 for association with serum insulin levels during an oral glucose tolerance test (OGTT) in a population-based sample of 6,039 middle-aged and treatment-naïve Danes. This evidence concerns the gene INS and type 2 diabetes mellitus.