Comparison of insulin receptor binding to monocytes and erythrocytes in newly diagnosed type II diabetes mellitus

Insulin binding to circulating monocytes and erythrocytes was studied in 20 healthy volunteers and in 25 obese hyperinsulinemic newly diagnosed type-II diabetics. In type-II diabetics insulin binding to monocytes as well as to erythrocytes was significantly decreased in comparison with healthy individuals. The lowered insulin binding of the diabetics was mainly caused by a loss of receptor number. Individual analysis of the binding data, however, shows a marked discrepancy between receptor binding to circulating monocytes compared with erythrocytes. Since insulin binding to erythrocytes shows a great variation and seems to be influenced by other factors beside insulin concentrations it is suggested that insulin receptors on monocytes should be preferred for evaluation of peripheral insulin sensitivity.