Objective To study the effect of type 2diabetes mellitus(T2DM)duration on cognition and its related risk factors in the elderly T2 DM patients.Methods One hundred and seventy-two elderly T2 DM patients were divided into group A with the duration <10years(n=60),group B with the duration being 10-19years(n=67)and group C with the duration≥20years(n=45).Forthermore,41 subjects with impaired glucose tolerance(IGT)served as an IGT group and 68 subjects served as a control group.The subjects underwent brain CT an...