A Prospective, Randomized, Open-Label Study Comparing the Efficacy and Safety of Preprandial and Prandial Insulin in Combination with Acarbose in Elderly, Insulin-Requiring Patients with Type 2 Diabetes Mellitus

Background: By delaying absorption of carbohydrates, acarbose can reduce preprandial hyperglycemia and delay the emergence of postprandial hyperglycemia. Patients and Methods: To evaluate whether acarbose can shorten the desirable time interval between insulin injection and meals, 60 elderly (>= 60 years) patients with unsatisfactorily controlled type 2 diabetes mellitus despite insulin use were enrolled in a randomized, open-label study of 16 weeks' duration. Two groups (n = 20 each) were randomized to receive isophane protamine biosynthetic human insulin 70/30 injections twice daily 30 min before meals plus acarbose 50 mg once daily (Group A) or three times daily (Group B) before meals, whereas the third group (n = 20) received isophane protamine biosynthetic human insulin 70/30 injections twice daily immediately before meals plus acarbose 50 mg three times daily before meals (Group C). Results: The required insulin dosage at study end was significantly less in Groups B and C than in Group A. Both continuous glucose monitoring data and the patients' self-monitoring data indicated that blood glucose variability parameters were significantly improved in Groups B and C in comparison with Group A, but there were no significant differences between Groups B and C. The incidence of hypoglycemia was low in all three groups. Conclusions: The absence of a significant difference in glucose variability between Groups B and C suggests that the addition of acarbose permitted adjustment of the insulin administration time from 30 min before meals to immediately before meals-which may be more convenient for patients-without affecting glycemic control.