Abnormally Increased Glomerular Filtration Rate in Short-term Insulin-treated Diabetic Subjects

Functional changes in the microvascular system appear to precede the morphological changes in the conjunctiva and retina of young subjects with diabetes mellitus. Similar functional changes might occur in the renal microvascular system and hemodynamics and possibly lead to a disturbance in the glomerular filtration rate. A preliminary study of the glomerular filtration rate (GFR) using the radioactive vitamin B12 method in young, insulin-treated patients with short duration of diabetes is reported. The average GFR in eighteen diabetic subjects was 137.8 ml. per min. per 1.73m2 with a standard deviation of 24.3 ml. in contrast to the average GFR in twelve control subjects which was 102.9 ml. with a standard deviation of 15.1 ml. This difference in GFR is highly significant. The reasons for the increased GFR in diabetics with short duration of their disease are discussed.