Insulin and proinsulin in normal and chemical diabetic children.

Plasma levels of total immunoreactive insulin and immunoreactive proinsulin were studied in 10 normal children and 15 children with chemical diabetes ranging in age from 5 to 13 years. Eleven of the children with chemical diabetes demonstrated significantly elevated TIRI during fasting and following glucose administration. There was a delay in the increment of plasma TIRI in four children with chemical diabetes, but otherwise their TIRI levels were normal. In these four children IRP was not significantly different from normal; however, in the remaining children with chemical diabetes, those with elevated TIRI, the IRP was elevated following glucose administration. Although the IRP was significantly elevated in the hyperinsulinemic group, the TIRI was also increased to such an extent that the glucose intolerance demonstrated in these patients could not be attributed to the elevated IRP.