We observed a significant correlation of increased glucose with elevated levels of Cystatin C, and an effect of T2D on the levels of CD26 (β = 45.8 pg/μg; p = 0.001) and CD14 (β = 168 pg/μg; p < 0.001) compared to subjects without T2D. This evidence concerns the gene CST3 and type 2 diabetes mellitus.