Effects of Vildagliptin Add-on Insulin Therapy on Nocturnal Glycemic Variations in Uncontrolled Type 2 Diabetes

INTRODUCTION: To investigate whether vildagliptin add-on insulin therapy improves glycemic variations in patients with uncontrolled type 2 diabetes (T2D) compared to patients with placebo therapy. METHODS: This was a 24-week, single-center, double-blind, placebo-controlled trial. Inadequately controlled T2D patients treated with insulin therapy were recruited between June 2012 and April 2013. The trial included a 2-week screening period and a 24-week randomized period. Subjects were randomly assigned to a vildagliptin add-on insulin therapy group (n = 17) or a matched placebo group (n = 16). Scheduled visits occurred at weeks 4, 8, 12, 16, 20, and 24. Continuous glucose monitoring (CGM) was performed before and at the endpoint of the study. RESULTS: A total of 33 subjects were admitted, with 1 patient withdrawing from the placebo group. After 24 weeks of therapy, HbA1c values were significantly reduced at the endpoint in the vildagliptin add-on group. CGM data showed that patients with vildagliptin add-on therapy had a significantly lower 24-h mean glucose concentration and mean amplitude of glycemic excursion (MAGE). At the endpoint of the study, patients in the vildagliptin add-on group had a significantly lower MAGE and standard deviation compared to the control patients during the nocturnal period (0000–0600). A severe hypoglycemic episode was not observed in either group. CONCLUSION: Vildagliptin add-on therapy to insulin has the ability to improve glycemic variations, especially during the nocturnal time period, in patients with uncontrolled T2D.