After further adjusting for the variables in model 2 plus BUN, creatinine, TG, HDL-c, LDL-c, Hs-CRP, hemoglobin, cystatin C, and HbA1c, diabetes status was a significant risk factor for subsequent cognitive decline (unstandardized β estimate = −0.50, 95%CI = −0.98 ~ −0.02, model 3). This evidence concerns the gene CST3 and diabetes mellitus.