After adjustment for confounding factors (age, gender, body mass index, diabetes mellitus, calcium, and phosphorus), creatinine, BUN, and Cystatin C remained correlated significantly with O-sulfotyrosine levels in multivariate linear regression analysis (β = 0.71, P < 0.001; β = 0.40, P = 0.002; β = 0.73, P < 0.001, respectively). This evidence concerns the gene CST3 and diabetes mellitus.