Insulin binding to erythrocytes in diabetes mellitus.

Insulin binding to erythrocytes was studied in diabetic patients. Insulin binding was lower in untreated diabetics and diabetic patients treated with diet or insulin than in normal subjects. Binding variation was mainly due to decreased binding site concentration in untreated and insulin-treated patients, and to lowered insulin binding site affinity in diet-treated patients. Several patients treated with hypoglycemic agents showed higher insulin binding due to increased binding site concentration. Insulin binding to erythrocytes may not always reflect the insulin binding status of insulin sensitive tissues.