Contribution of postprandial versus interprandial blood glucose to HbA1c in type 1 diabetes on physiologic intensive therapy with lispro insulin at mealtime.

Abstract

The substitution of Hum-R with lispro (group 2) resulted in lower postprandial blood glucose, but greater postabsorptive blood glucose (P < 0.05 vs. group 1). The postprandial blood glucose AUC was lower (161 +/- 19 vs. 167 +/- 20 mg.100 ml-1.h-1), but the postabsorptive blood glucose AUC was greater (155 +/- 22 vs. 142 +/- 19 mg.100 ml-1.h-1) (P < 0.05). Therefore, the 24-h blood glucose AUC was no different (NS). Consequently, HbA1c was no different (NS). This occurred because in group 2, mealtime lispro resulted in normal prandial plasma insulin, but also resulted in lower interprandial concentration (P < 0.05 vs. group 1). When NPH was added to lispro (30% at breakfast, 40% at lunch, 10% at dinner) in group 3, postabsorptive plasma insulin was similar to group 1 (NS), in group 3, the postprandial blood glucose AUC (153 +/- 17 mg.100 ml-1.h-1) was lower and the postabsorptive blood glucose AUC was no different, as compared with group 1 (NS). Therefore, the 24-h blood glucose AUC was lower (147 +/- 17 vs. 155 +/- 21 and 158 +/- 20 mg.100 ml-1.h-1), and HbA1c was lower (6.41 +/- 0.12 vs. 6.84 +/- 0.2 and 6.96 +/- 0.2% (groups 3, 1, and 2 respectively, P < 0.05). Frequency of hypoglycemia was greater in group 2 (P < 0.05), but not in group 3 (NS) vs. group 1.