Abstract: ObjectiveTo explore the effect of sitagliptin， a dipeptidyl peptidase 4 inhibitor， on carotid intimamedia thickness (IMT)in insulintreated patients with type 2 diabetes mellitus (T2DM). MethodsThis prospective， randomized， parallel group and comparative study included 172 insulintreated patients with T2DM who were randomly allocated to either the sitagliptin group (n=84) or the control group (n=88). The primary outcomes were changes in mean IMT of the carotid artery measured by echography at the end of a 12months′  treatment. ResultsChanges in the mean IMT of the carotid arteries were significantly greater after sitagliptin treatment compared with conventional treatment (P＜0.05). After followup of 12 months， sitagliptin， but not conventional treatment， significantly reduced the mean IMT of carotid arteries relative to the baseline. Sitagliptin had a more potent glucoselowering effect compared with the conventional treatment (P＜0.05)， without increasing hypoglycemic episodes or body mass. ConclusionSitagliptin attenuated the progression of carotid IMT in insulintreated T2DM patients with glucoselowering effect.

Key words: diabetes mellitus, type 2； atherosclerosis；dipeptidylpeptidase Ⅳ inhibitors；carotid intimamedia , thickness