BACKGROUND: Vildagliptin is believed to improve glucose variability by restoring the physiologic pattern of insulin secretion and improving beta and alpha cells' sensitivity to glucose but with less increase in insulin secretion compared to sulfonylureas resulting in similar glucose levels but with less risk of hypoglycemia.
OBJECTIVE: To compare the effect of vildagliptin and glimepiride on glucose variability among Type 2 diabetic patients not controlled on metformin alone.
METHODS: This investigation is a prospective, interventional, open-labeled, active control, parallel assignment, efficacy study that included patients with inadequate glycemic control on monotherapy with metformin, randomly assigned either to vildagliptin or glimeparide. For one month, one group took vildagliptin 50mg/tablet one tablet twice a day while the other group took glimepiride 1 mg/tablet one tablet once a day. Subjects were asked to monitor their capillary blood glucose at seven points throughout the day for 35 days.
RESULTS: A total of 18 patients were recruited for the study and randomly assigned to either of the two treatment arms. However, only 16 patients completed the study. The vildagliptin and glimepiride groups had comparable blood sugars at baseline and at the end of the study although the glimepiride group showed a steeper decline in the blood sugar levels. Subjects in both groups showed a downward trend in the blood glucose values from day one to the 35th day with comparable mean glucose values between treatments and across combinations of day and treatment. Likewise, mean postprandial incremental area under the curve (AUCpp)and mean amplitude of glycemic excursions (MAGE) were comparable across treatments and across combinations of day and treatment, although the Glimepiride group showed relatively higher MAGE values.
CONCLUSION: Vildaglipitin and glimepiride both improved glycemia of patients with uncontrolled blood sugar on monotherapy with metformin as both groups showed downward glucose trend, although vildagliptin showed relatively less abrupt glucose lowering effect suggesting lesser risk of hypoglycemia. Mean postprandial glucose excursions of the two groups were also comparable but the vildagliptin arm had lower MAGE and may suggest an improvement in both ?- and ?-cell function.