Insulin therapy - From insulin secretion to insulin therapy

Which insulin for which diabetic?: Besides type 1 insulin-dependent diabetes, insulin therapy may be indicated in certain type 2 patients whose glucose regulation is insufficiently controlled by diet or oral antidiabetic drugs or who require temporary control with insulin. Target glucose level: Blood glucose should be as close as possible to normal levels, i.e. 0.8 g/l in the fasting state and 1.40 g/l after meals. However the target must be calculated according to the patients age and diabetic risks. Insulin requirements: Baseline insulin secretion lies in the 0.4 to 0.5 IU/kg/d range which is about two-thirds of the overall daily insulin secretion. Acute secretion reaches 0.3 IU/kg/d. Mean insulin requirements in adults are approximately 0.7 to 0.9 IU/kg/d, i.e. 50 to 60 U/d for a 70-kg adult. Insulin sources: Bovine and porcine insulins can lead to the development of anti-insulin antibodies. Semi-synthetic or recombinant human insulins have been obtained by genetic engineering. The kinetics of one insulin analog, Humalog, has been modified compared with ordinary insulin by transposition of 2 amino acids. Available insulins: Ordinary rapid-acting insulins should be injected 20 minutes before meals and never just before eating. Intermediate-acting isophane insulins (14-18 hr) have the same bioavailability characteristics and can be used in combination with ordinary insulin. Long-acting insulins cannot be used with pens; they are active for 24 hours. Very-long-acting insulins (Ultralente) are active for 36 hours. Insulin analogs administered just before food intake can reduce the risk of postprandial hyperglycemia and late post-prandial hypoglycemia compared with rapid-acting insulins. (C) 1998, Masson, Paris.