BACKGROUND: Whether a dipeptidyl peptidase-4 (DPP-4) inhibitor can attenuate atherosclerosis is still controversial. Some clinical trials reported that DPP-4 inhibitors in diabetes patients without a previous history of cardiovascular (CV) events could reduce carotid intima-media thickness (IMT). However, in the PROLOGUE study, which enrolled diabetes patients both with and without previous CV events, sitagliptin failed to slow the progression of carotid IMT relative to conventional therapy.
AIM AND METHODS: We hypothesized that the effect of DPP-4 inhibitors on carotid atherosclerosis might be different between the primary and secondary prevention groups. We performed a post hoc analysis of the PROLOGUE study and compared the effects of sitagliptin and conventional therapy on changes in carotid IMT in subgroups with or without previous CV events.
RESULTS: No significant difference in the IMT changes between the treatment groups was found in the secondary prevention subgroup (sitagliptin, N = 102; conventional, 111). However, in the primary prevention subgroup (sitagliptin, 120; conventional, 109), we found significant inhibitory effects of sitagliptin on mean and max internal carotid artery IMT [estimated group difference: −0.096 mm (95% CI −0.175 to −0.018, p = 0.017) and −0.162 mm (95% CI −0.272 to −0.052, p = 0.004), respectively], although there was no significant difference in the common carotid artery IMT.
CONCLUSIONS: Our data suggest that there is a favorable effect of DPP-4 inhibitor treatment on carotid atherosclerosis in diabetes patients without previous CV events.