Insulin aspart

Comparative studies

In a double-blind, crossover study of insulin aspart or soluble human insulin before meals and protamine zinc insulin before bedtime, 90 of 104 patients with type 1 diabetes completed the trial [ ]. Insulin aspart improved postprandial control by reducing hyperglycemic and hypoglycemic variations, but night-time control was inferior. There were 547 hypoglycemic episodes in the aspart period compared with 615 in the regular insulin period (no significant difference). However, there were only 20 major hypoglycemic events in 16 patients using aspart versus 44 events in 24 patients using human insulin. One patient was withdrawn with fatigue and anorexia during aspart. Convulsions during hypoglycemia occurred once in each group.

Insulin aspart had an increased maximal effect compared with regular insulin in euglycemic clamps in non-diabetics [ ].

In an open comparison of insulin aspart and regular human insulin for 6 months in 882 patients with type 1 diabetes and extended to 714 patients for another 6 months, postprandial glucose concentrations were lower with insulin aspart [ ]. HbA _1c was slightly but significantly lower (7.78 versus 7.93%). There were no differences in hypoglycemic periods or adverse events.

Insulin aspart has been compared with regular insulin in 1065 patients for 26 weeks [ ]. HbA _1c improved significantly with aspart. The number of major attacks of hypoglycemia fell in the aspart group from 11 to 8%; there were no other differences.

Insulin aspart has been compared with buffered regular insulin by continuous subcutaneous infusion [ ]. There was some crystal formation with both formulations, but less with insulin aspart. Patients who used aspart required a slightly higher basal dose of insulin but had fewer unexplained attacks of hypoglycemia.

Frequent addition of isophane to a regimen of insulin aspart is unnecessary, as has been shown in a multicenter, multinational, randomized, open study in 368 patients followed for 64 weeks [ ]. Frequent addition of isophane up to four times daily to insulin aspart did not improve HbA _1c or change the number of episodes of hypoglycemia compared with regular insulin combined with isophane. Only postprandial blood glucose concentrations were reduced.

When insulin lispro and insulin aspart were compared in a single-blind, randomized, crossover study in 14 patients with type 1 diabetes, insulin lispro had a faster onset of action but a shorter duration [ ]. However, in another study the pharmacokinetic and the pharmacodynamic profiles of insulin aspart compared with human insulin were the same in 24 healthy Japanese as in non-Japanese [ ]. Insulin aspart and insulin lispro were equally effective in another 24 patients with type 1 diabetes [ ].