Objective The present study aimed to compare the effects of the dipeptidyl peptidase-4 (DPP-4) inhibitors vildagliptin and saxagliptin on 24 hour acute glucose fluctuations in Chinese patients with type 2 diabetes mellitus (T2DM) inadequately controlled with a combination of metformin and sulfonylurea. Research design and methods This was a 24 week, prospective, randomized, open-label, active-controlled study. Patients (N = 73) with T2DM who had inadequate glycemic control (HbA1c 7.0%-10.0%) with a stable dosage of metformin plus gliclazide for more than 3 months were randomized to receive either vildagliptin 50 mg twice daily (BID, n = 37) or saxagliptin 5 mg once daily (QD, n = 36). Change in mean amplitude of glycemic excursions (MAGE) was assessed at the end of 24 weeks. Results At baseline, the mean (±SD) age was 62.9 ± 6.55 years, disease duration was 7.0 ± 2.33 years, and HbA1c was 8.4 ± 0.68%. After 24 weeks of treatment, the MAGE decreased from 5.81 ± 1.16 mmol/L to 4.06 ± 0.86 mmol/L (p<0.001) in the vildagliptin group and from 5.66 ± 1.14 mmol/L to 4.79 ± 1.25 mmol/L (p = 0.003) in the saxagliptin group. The mean change in MAGE in the vildagliptin group was significantly greater than that in the saxagliptin group (1.74 ± 0.48 mmol/L vs. 0.87 ± 0.40 mmol/L, p<0.001). The mean change in HbA1c, from baseline to the study endpoint, in the vildagliptin and saxagliptin groups, was 1.22 ± 0.40% and 1.07 ± 0.36%, respectively, with no significant difference between the groups (p = 0.091). The overall safety and tolerability of vildagliptin and saxagliptin were similar. The limitations of the study were a small number of patients and open-label administration of the study drug. Conclusion Vildagliptin produced a significantly greater reduction in acute glucose fluctuations compared with saxagliptin when added to a dual combination of metformin and sulfonylurea in Chinese patients with T2DM. Chinese clinical trial registration number ChiCTR-TRC-13003858.
Keywords: Acute glucose fluctuation; CGMS; Chinese type 2 diabetes mellitus; DPP-4 inhibitors.