Analyses of RBC insulin receptor bindings in chronic liver disease.

I-insulin binding to erythrocytes was measured to evaluate the role of insulin receptors in the mechanism of insulin resistance in partients with chronic liver disease (CLD). Patients with CLD were divided into two groups by the fasting plasma glucose level (FBS) and the glucose disappearance rate (k-glucose) during intravenous glucose tolerance tests: one with normal FBS and normal k-glucose (group I), and the other with higher FBS and lower k-glucose (group II). Insulin receptor bindings were reduced in group I patients compared with those of normal controls, but were not reduced in group II patients. Fasting insulin levels were significantly higher in group I patients than those in normal subjects, and down-regulation by hyperinsulinemia might be the cause of reduced insulin receptor bindings in these patients. However down-regulation of insulin receptors was not associated with glucose intolerance. So it is suggested that insulin resistance in CLD is not due to a primary defect of insulin receptors in peripheral tissues, and down-regulation of insulin receptors is an epiphenomenon of hyperinsulinemia.