Metabolic efficacy of preprandial administration of Lys(B28), Pro(B29) human insulin analog in IDDM patients. A comparison with human regular insulin during a three-meal test period.

Objective: The objective of this study was to compare the efficacy of the rapid-acting Lys(B28), Pro(B29) human insulin analog, insulin lispro, with currently available short-acting human insulin in a multiple injection therapy (MIT) regimen with respect to blood glucose and plasma insulin profiles and to serum metabolites (lactate, free fatty acids, glycerol, and beta-hydroxybutyrate) in 12 well-controlled type 1 diabetic subjects (8 male, HbA1c 6.8 +/- 0.9% [mean +/- SD]).

Research Design And Methods: After a run-in period of 4 weeks, patients were treated with either lispro at mealtime or human insulin 30 min before the meal for two periods of 4 weeks in a randomized open-label crossover study. Intermediate-acting insulin (NPH insulin) was given at bedtime. At the end of both study periods, metabolic profiles were assessed from 10:00 P.M. to 7:00 P.M. the next day.

Results: During the treatment periods, glycemic control was stable during lispro but improved during human insulin (delta HbA1c lispro 0.1 +/- 0.48, NS; human insulin -0.41 +/- 0.34%, P < 0.05). Glucose excursions, as measured by the incremental AUC, during the day and for the 2-h postprandial periods, were lower, although not significantly, for lispro. Insulin profiles demonstrated a faster rise after administration of lispro as compared with human insulin, peaking at 61 +/- 11.9 and 111 +/- 48.1 min (P < 0.01). Glycerol levels showed a slight increase before lunch and dinner, suggestive of enhanced lipolytic activity and compatible with the lower insulin levels.

Conclusions: Lispro insulin applied in an MIT regimen creates more physiologic insulin profiles and tends to lower the glycemic excursions during the day compared with short-acting insulin. The analog can be applied safely in an MIT regimen, with mealtime intervals up to 5 h.