Rational use of insulin analogues in the treatment of type 1 diabetes mellitus.

Long-term near-normoglycaemia in Type 1 diabetes protects against the onset and/or progression of microangiopathic complications. To successfully reach the goal while avoiding the risk of hypoglycaemia and hypoglycaemia unawareness, insulin therapy has to be physiological. Mealtime insulin should be given as a bolus injection before, or both before and after, a meal. In addition, basal insulin between meals should be replaced by an insulin preparation with a square wave action profile. Rapid-acting insulin analogues are the mealtime insulin preparations of choice. Either continuous subcutaneous insulin infusion (CSII), or once day injection of the long-acting insulin analogue glargine is required to optimally replace basal insulin. In Type 1 diabetes the benefits of mealtime treatment with rapid-acting insulin analogues become apparent only to the extent to which replacement of basal insulin is optimised at the same time. This has been difficult in the past with the peak insulin NPH, but it is nowdays easier with the nearly peakless long-acting insulin analogue glargine. As compared to NPH, glargine reduces the risk for nocturnal hypoglycaemia, and at the same time improves HbA1c similarly to CSII.