Long-term miglitol administration suppresses postprandial glucose-dependent insulinotropic polypeptide secretion

Several studies indicated that short-term administration of α-glucosidase inhibitors (α-GIs) significantly reduces postprandial glucose-dependent insulinotropic polypeptide (GIP) secretion. However, little is known about the long-term effect. We investigated the effects of long-term miglitol administration on GIP secretion and body weight in patients with type 2 diabetes.

This study included ten patients with type 2 diabetes administered 150 mg miglitol and another ten patients treated with glinide. We evaluated postprandial GIP, plasma glucose, insulin and triglyceride levels at baseline and after 12 months of each administration.

After 12 months, postprandial glucose levels significantly decreased in each group. Miglitol significantly suppressed postprandial plasma insulin levels at 30 min compared to glinide (97.9 vs. 257.3 pmol/l; P < 0.01). The fasting GIP level in the glinide group after 12 months significantly increased compared to before administration (15.5 vs. 24.5 pg/ml), but miglitol did not affect the fasting GIP level. Miglitol significantly reduced postprandial GIP levels at 30, 60 and 120 min (28.8, 45.3 and 42.4 vs. 137.4, 130.8 and 108.7 pg/ml; P < 0.01, P < 0.05, P < 0.01) and the delta area under the curve of GIP (12M−0M) (−70.8 vs. 57.2 pg min/ml; P < 0.05) compared to glinide. Miglitol significantly decreased postprandial triglyceride levels, but glinide did not. Miglitol slightly reduced body weight (−0.6 kg) and waist circumference (−1.0 cm); however, glinide slightly increase body weight (+0.4 kg) and waist circumference (+0.6 cm).

We conclude long-term miglitol administration suppressed postprandial GIP secretion, in association with improvements in body weight, postprandial blood glucose, insulin and triglyceride levels.