The Beneficial Effect of α-glucosidase Inhibitor on Glucose Variability Compared with Sulfonylurea in Taiwanese Type 2 Diabetic Patients Inadequately Controlled with Metformin: Preliminary Data

Aims: Although sulfonylurea added to metformin is the first oral drug combination regimen for patients with type 2 diabetes recommended by the American Diabetes Association/European Association for the Study of Diabetes consensus statement, it does not allow for individualizing and optimizing therapy with respect to sustaining glycemic control and the reduction of glucose variability. We therefore sought to investigate acarbose as an alternative to glibenclamide in combination with metformin and compare the effects on metabolic control and glucose variability.

Methods: Type 2 diabetic patients 30-70 years of age with glycosylated hemoglobin 7.0%-11.0% while treated with one or two oral antidiabetic drugs were successively enrolled. After 8 weeks of run-in with metformin 500 mg thrice daily, either acarbose 50 mg or glibenclamide 2.5 mg three times daily was randomly added on and force titrated to acarbose 100 mg or glibenclamide 5.0 mg three times daily for the subsequent 16 weeks. Demographic data, biochemical data and continuous glucose monitoring system data were recorded upon randomization and at the end of the study. Various parameters that measure glucose variability were derived from the continuous glucose monitoring system data.

Results: Of the 51 type 2 diabetes patients enrolled, data from 40 subjects, 20 in each group, were analyzed after excluding those unqualified information. Both drug combinations improved glycemic control. Glucose variability, expressed as mean amplitude of glycemic excursion or continuous overall net glycemic action and mean of daily differences, decreased significantly (all P<.05) after the addition of acarbose but not glibenclamide. The acarbose-metformin combination has the additional benefits of weight reduction and shorter durations of hyperglycemia compared with metformin monotherapy.

Conclusions: This study suggests that both intraday and interday glucose variability are more effectively reduced by the acarbose-metformin combination than by the glibenclamide-metformin combination, while both combinations reduce the overall glucose level equally.