A comparison of insulin lispro and buffered regular human insulin administered via continuous subcutaneous insulin infusion pump

This study compared glycemic control achieved with insulin lispro or buffered regular human insulin in patients with Type 1 diabetes treated with continuous subcutaneous insulin infusion (CSII) using an external insulin pump. In this 24-week multicenter, randomized, two-way crossover, open-label trial, 58 patients on CSII with adequate glycemic control received either insulin lispro or buffered regular human insulin for 12 weeks, followed by the alternate treatment for another 12 weeks. Efficacy and safety measures included hemoglobin A_1c (HbA_1c) at baseline and endpoint, home blood glucose monitoring, hypoglycemia, and frequency of pump catheter occlusion. Patients consumed a standard test meal on three occasions, with determinations of fasting, 1- and 2-h postprandial glucose values. Insulin lispro use was associated with a significantly lower HbA_1c than was buffered regular human insulin (7.41±0.97 vs. 7.65±0.85 mmol/l; P=.004). Fasting serum glucose values before the test meal were similar between the two therapies. The 1-h (11.16±4.29 vs. 13.20±4.68 mmol/l; P=.012) and 2-h (9.64±4.10 vs. 12.53±4.64 mmol/l; P=.001) postprandial glucose concentrations were significantly lower during treatment with insulin lispro. No differences between treatments were observed in basal or bolus insulin doses, weight gain, or the incidence and rate of hypoglycemia, hyperglycemia, or pump occlusions. When used in external pumps, insulin lispro provides better glycemic control than buffered regular human insulin with a similar adverse event profile.