Effect of Adding Vildagliptin to Insulin in Hemodialyzed Patients with Type 2 Diabetes: A Randomized Multicentric Prospective Study—The VILDDIAL Study

AIM: To evaluate the effect of adding the dipeptidyl-peptidase-4 inhibitor vildagliptin to insulin on the glycaemic control of patients with type 2 diabetes undergoing haemodialysis. METHODS: Overall, 65 insulin-treated patients with type 2 diabetes undergoing haemodialysis (HbA1c: 7.3% +/- 1.1%; age: 70.5 +/- 8.5 years) were randomized (1:1) either to receive vildagliptin 50 mg/day in addition to insulin (vildagliptin-insulin group) or to pursue their usual insulin regimen (insulin-only group). Continuous glucose monitoring (CGM) was performed for 48 +/- 6 hours at baseline and at week 12. The primary study endpoint was change from baseline in mean interstitial glucose using CGM. The secondary endpoints included other CGM variables and glucose control markers. RESULTS: After 12 weeks, a greater reduction in mean CGM glucose from baseline was observed in the vildagliptin-insulin group compared with the insulin-only group, although the between-treatment difference was not statistically significant (mean difference [CI 95%]: -0.96 mmol/L [-2.09; 0.18] vs. -0.29 mmol/L [-1.29; 0.76], P = 0.32). However, a significant decrease from baseline in HbA1c, glycated albumin and insulin daily doses was observed in the vildagliptin-insulin group versus the insulin-only group (-0.6% [-1.19; -0.1], P < 0.01), in the vildagliptin-insulin group versus no change in the insulin-only group (-130.6 mumol/L [-271; 10.7] vs. +36.2 mumol/L [-164.4; 236.9], P = 0.04 and - 5.9 IU/day [-1.8; 7.1] vs. +1.1 IU/day [-14.5; 16.6], P = 0.01, respectively). There was no significant difference in the percentage of time spent in hypoglycaemia using CGM, occurrence of severe hypoglycaemia or number of adverse events. CONCLUSION: In this study, vildagliptin added to insulin improved glycaemic control with an associated insulin-sparing effect in patients with type 2 diabetes undergoing haemodialysis and was well tolerated.