The importance of the time interval between insulin injection and breakfast in determining postprandial glycaemic control--a comparison between human and porcine insulin.
This study assessed the effect of the time interval between insulin injection and breakfast in determining subsequent postprandial glycaemic control and also whether this differed between highly purified porcine insulin and human insulin (crb) in six diabetic patients (age range 24-36 years, duration of diabetes greater than 10 years) usually treated with twice daily Actrapid MC and Monotard MC and with stable insulin requirements and diabetic control. On separate mornings each patient was given, after an overnight fast, their usual dose of either Actrapid MC and Monotard MC or Humulin S and Humulin Zn injected 5, 20, or 40 min before a standard breakfast. The postprandial glycaemic profile was not significantly different at any of the three time intervals with Actrapid MC and Monotard MC. However, with the human insulin the profile was significantly better at the 40 min interval than at the 5 min interval (p less than 0.05) and this was also better than any of the profiles with the porcine insulin, there being a significant difference between the two types of insulin (p less than 0.05). These findings suggest that the time interval between insulin injection and breakfast may be more important with human insulin than with porcine insulin.