Background: DPP-4 inhibitors have been reported to have beneficial effects on endothelial function as sitagliptin increases circulating endothelial progenitor cells (EPCs) via inhibition of plasma stromal derived factor-1 alpha (SDF-1α). However, its mechanisms are unclear. We evaluated whether DPP-4 inhibitor teneligliptin increases the number of circulating EPCs through inhibition of SDF-1α metabolism and improves flow mediated vascular dilatation (FMD) in type 2 diabetes mellitus (T2DM) patients with acute coronary syndrome (ACS) or its risk factors.
Methods: This study was a prospective, single-center, open-label, randomized controlled trial. A total of 16 patients with present or past history of ACS or multiple cardiovascular risk factors were enrolled, and who take any medicine for diabetes, whose HbA1c > 7.5% and/or peak CPK > 2000 IU/ml, were excluded. Variable of glucose and lipids, the number of EPCs, activity levels of DPP-4 and SDF-1α and FMD were evaluated at baseline and at 28±4 weeks after enrollment in all patients. They were randomly assigned into 2 groups either 20mg per day teneligliptin or control. Finally, 8 patients were included in teneligliptin group and 8 in control. All data were analyzed by paired t-test, and p < 0.05 was considered statistically significant.
Results: DPP-4 activity (∆-509.5±105.7 vs. ∆32.8±53.4 μU/ml) and SDF-1α levels (∆-695.6±443.2 vs. ∆11.1±193.7 pg/ml) were significantly decreased after 28 weeks in teneligliptin group compared to control, respectively. Number of EPCs, and variables of glucose and lipids were not significantly different between two groups before and after 28 weeks. However, FMD was significantly improved in the teneligliptin group compared to control (∆3.8±2.1 vs. ∆-0.3±2.9%, p = 0.006) after 28 weeks treatment.
Conclusion: These results indicate that teneligliptin improves FMD by different mechanisms from the increase of blood EPC number via SDF-1α.
N. Akashi: None. T. Umemoto: None. Y. Hodaka: None. T. Fujiwara: None. K. Yamamoto: None. Y. Taniguchi: None. K. Sakakura: None. H. Wada: None. S. Momomura: None. H. Fujita: None.