Diabetic retinopathy and previous insulin therapy as compared with insulin requirement

The aim of study was the comparison of the Biostator-determined insulin requirement with the degree of diabetic retinopathy and previous insulin therapy. Twenty-three patients with insulin-dependent diabetes mellitus of more than 10 years' duration were studied. The mean insulin dosage during the last ten years was calculated, and the degree of retinopathy and insulin requirement during a 2-day connection to the Biostator were determined. In comparing the mean insulin supply during the last ten years with the Biostator-determined insulin requirement in patients with proliferative retinopathy, the significant difference occurred only in patients with diabetes of less than 15 years' duration (P less than 0.05). Such a difference was not found in patients with background retinopathy. We conclude that the patients with more advanced changes in the eye fundus, particularly those with diabetes of shorter duration, had received generally less insulin than was required as determined by the Biostator. It may be inferred that long-term inadequate insulin supply accelerates the development of microvascular complications in diabetes.