The effect of acarbose and miglitol (BAY-M-1099) on postprandial glucose levels following ingestion of various sources of starch by nondiabetic and streptozotocin-induced diabetic rats

The effect of two α-glucosidase inhibitors, acarbose (BAY-G-5421) and miglitol (BAY-M-1099), on postprandial glucose levels following intubation of corn, rice, spaghetti and potato (0.5 g/100 g body wt) was evaluated in nondiabetic and diabetic rats. The peak plasma glucose level and total incremental glucose were significantly decreased following ingestion of each starch source when acarbose (8 mg/100 g body wt) or BAY-M-1099 (2 mg/100 g body wt) were simultaneously intubated. The effect of both inhibitors was more pronounced in diabetic rats than in nondiabetic rats, and their effect on digestion was in a substrate-specific manner. Potato starch digestion was inhibited 58 ± 11% by BAY-M-1099, and by acarbose, 38 ± 9%. Rice starch digestion was inhibited by 65 ± 2% by acarbose, and by BAY-M-1099, only 30 ± 9%. Both drugs had a similar inhibitory effect when corn or spaghetti was ingested. Bay-M-1099 appears to be mroe potent than acarbose on both a weight-per-weight basis and on a molar basis. When corn or rice was used, only 2 mg of BAY-M-1099 was required to achieve a similar inhibitory effect to that of 8 mg of acarbose (9.7 x 10^-3 M vs. 12.2 x 10^-3 M). Since both drugs blunted to varying degrees the rise in glucose level following starch ingestion, they may be a useful adjuvant in the treatment of diabetic subjects. Simultaneous use of both drugs in therapeutic treatment should be seriously considered.