The comparison of second phase insulin secretion in patients treated with repaglinide or gliclazide

Aims: Sulfonylurea with long half-life such as gliclazide has sustained stimulation on insulin secretion compared to repaglinide which has short half-life for only about 1 h. In this hospital cohort, randomized, cross-over study, we used modified low dose graded glucose infusion test (M-LDGGI) to evaluate second phase insulin secretion after 4 months of treatment with either gliclazide or repaglinide. Methods: Sixteen fresh type 2 diabetes with age of 49.5 ± 2.6 years old and BMI of 25.3 ± 0.9 kg/m² were included. After titration and maintain dose stage, all cases were randomized to the repaglinide or gliclazide treatment for 4 months. At the end of each treatment period, an M-LDGGI was done. Results: The general linear model repeated measurement was used to evaluate the plasma glucose, insulin and insulin/glucose curve during M-LDGGI. Although the plasma insulin and insulin/glucose ratios were higher at 40 min and 100-120 min, they did not reach statistically significant. The area under curve of the plasma glucose, insulin and insulin/glucose ratio was also used to evaluate the secretory capacity of beta cell. Although the AUC of the ratio of plasma insulin/plasma glucose seems to be more evident than the curves, they are still not significantly different with each other. Conclusions: In conclusion, although non-significant, better second phase insulin secretion could be noted with treatment of repaglinide than gliclazide for 4 months. Further study with longer duration and larger study cohort are needed to solve this interesting and important question.