Contribution of Postprandial Versus Interprandial Blood Glucose to HbA (1c) in Type 1 Diabetes on Physiologic Intensive Therapy With Lispro Insulin at Mealtime

    loading  Checking for direct PDF access through Ovid

Abstract

OBJECTIVE

To quantitate the contribution of postprandial blood glucose, which improves with the short-acting insulin analog lispro [Lys(B28),Pro(B29)] in type 1 diabetes, to the overall 24-h blood glucose concentration and the long-term HbA1c concentration under conditions of different postabsorptive blood glucose.

RESEARCH DESIGN AND METHODS

A total of 24 type 1 diabetic patients on long-term intensive therapy with premeal human regular insulin (Hum-R) and bedtime NPH were randomly assigned to a continuation of Hum-R (group 1, n = 8), lispro (group 2, n = 8), or lispro + NPH (in variable proportions) administered at mealtime (group 3, n = 8) for 3 months. NPH administered at bedtime was continued in all three groups. Data from home blood glucose monitoring were collected, and a 24-h plasma glucose and insulin profile was obtained during a 2-day hospital visit to calculate areas under the postprandial glucose curve (3.5 h after breakfast, 3.5 h after lunch, and 3.0 h after dinner for a total of 10.0 h) and the postabsorptive blood glucose curve (the remaining 14.0 h out of 24.0 h) (AUC). Eight nondiabetic subjects were also studied.

RESULTS

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 [centered dot] 100 ml-1 [centered dot] h-1), but the postabsorptive blood glucose AUC was greater (155 +/- 22 vs. 142 +/- 19 mg [centered dot] 100 ml-1 [centered dot] 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 [centered dot] 100 ml-1 [centered dot] 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 [centered dot] 100 ml-1 [centered dot] 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.

CONCLUSIONS

Lispro administered at mealtime, which improves postprandial blood glucose, should be associated with optimized replacement of basal insulin to prevent deterioration of postabsorptive blood glucose. NPH administered four times daily normalizes interprandial daily plasma insulin concentration and decreases mean daily blood glucose and HbA1c, with no increase in hypoglycemia. Diabetes Care 22:795-800, 1999

Related Topics

    loading  Loading Related Articles