Insulin-like Growth Factors

Abstract

To determine whether two insulin-like growth factors (IGF I and IGF II) influence the course of diabetic retinopathy, we measured the concentrations of these factors in 80 adult patients with diabetes and in 62 control subjects. In seven patients with Type I diabetes and rapidly deteriorating vision as a result of proliferative and exudative retinopathy, the serum concentration of IGF I was 722±41 ng per milliliter (mean ±S.E.M.), as compared with 381±48 ng per milliliter in 26 patients who had Type I diabetes without retinopathy or with less severe forms of it, and 302±15 ng per milliliter in the controls (P<0.001 for both comparisons). Serum concentrations of IGF II were normal in subjects with Type I diabetes but were somewhat depressed in those with Type II disease.