In contrast with the noted increase in sCD26/DPP-IV levels, the fasting serum levels of active GLP-1 were significantly lower in T2DM subjects with MetS [3.74 (2.29) pmol/L] than in normal subjects [4.26 (3.89) pmol/L] (p = 0.020). This evidence concerns the gene GLP1R and type 2 diabetes mellitus.