Exogenous insulin needs. Relationship with duration of diabetes, C-peptidemia, insulin antibodies, and retinopathy.

The study included 75 young diabetics, having a mean age of 13.7 (+/- 3.4) years, and whose diabetes duration was 5.0 (+/- 3.1) years. All of the subjects were insulin dependent, and none had developed insulin resistance. Injections of either conventional or purified insulin were used. The subjects' diets were "spontaneously balanced", and their physical exercise was similar to non-diabetic school-age children. The 75 diabetics were arbitrarily divided into two groups, A and B, according to their average insulin dose/kg, either less than 1 U/kg or greater than 1 U/kg. Groups A and B were comparable according to their age, age of diabetic onset, degree of diabetic control, frequency of retinal complications, proportion of different insulin types, and concentration of beef or pork insulin antibodies. Insulin antibodies were therefore not responsible for any modification in insulin needs. Insulin needs per kg were very significantly correlated to residual secretion of endogenous insulin (r = -0.34; p less than 0.001). They were equally dependent on the duration of diabetes probably because of the progressive beta cell exhaustion. Insulin needs were also weakly negatively correlated to weight, therefore the heaviest diabetics injected an insulin/kg dose relatively less than the lighter diabetics.