Comparison of insulin lispro with regular human insulin for the treatment of type 1 diabetes in adolescents

Background: Although insulin lispro (insulin LP) has been shown to improve postprandial blood glucose (BG) control and reduce hypoglycemic episodes in adult patients with type I diabetes, there appear to have been few clinical studies focusing on its use in adolescents. Objective: This study compared the effects of insulin LP with those of regular human insulin (insulin R) on postprandial BG control and hypoglycemia in adolescents with type I diabetes. Methods: In this crossover, open-label study, adolescents between the ages of 9 and 18 years who had reached Tanner stage 11 puberty were randomized to receive either insulin LP immediately before meals or insulin R 30 to 45 minutes before meals, in addition to daily intermediate-acting insulin. After 4 months, patients were switched to the alternate treatment sequence. Eight-point. BG profiles, hypoglycemia rate, and glycosylated hemoglobin (HbA(1c)) were measured at baseline and end point. Results: Four hundred eighty-one adolescents participated in the study at 53 investigative sites in 15 countries; 463 were randomized to treatment (228 insulin LP, 235 insulin R), and 457 completed the study. Insulin LP given before breakfast resulted in significantly lower mean (+/-SD) 2-hour postprandial BG levels compared with insulin R (9.7 +/- 4.0 mmol/L vs 10.6 +/- 4.3 mmol/L, respectively; P < 0.001). Insulin LP given before dinner resulted in significantly lower 2-hour postprandial BG levels compared with insulin R (8.6 +/- 3.5 mmol/L vs 9.3 +/- 3.7 mmol/L; P = 0.003). No differences were seen between treatments in 2-hour postprandial BG levels after the midday meal. Mean baseline HbA(1c) values were similar between sequence groups, and no between-group difference in HbA,, was observed at end point (insulin LP, 8.69% +/- 1.52%; insulin R, 8.70% +/- 1.65%). Treatment with insulin LP resulted in a significantly lower incidence of hypoglycemic episodes per patient per 30 days compared with insulin R (4.02 +/- 4.5 vs 4.37 +/- 4.5, respectively; P = 0.023) and significantly fewer hypoglycemic episodes between midnight and 6 AM (1.0 +/- 1.9 vs 1.7 +/- 2.6; P < 0.001). Conclusions: In adolescents with type 1 diabetes, insulin LP significantly improved postprandial glycemic control and reduced episodes of nocturnal hypoglycemia compared with insulin R. Insulin LP was well tolerated and effective as part of an intensified insulin regimen in this study population.