The purpose of this communication is to present our observations on a group of diabetic patients who have been observed for a year or more during treatment with one daily dose of protamine zinc insulin. Furthermore, we plan to discuss briefly our routine therapy as well as to review the events which contributed to the adoption of the principles presented in this publication.
Protamine zinc insulin has been used in the treatment of diabetes mellitus for nearly four years. True, the original compound as prepared by Hagedorn1 has undergone slight modifications, but basically the product is still regular insulin which has been mixed with protamine (a simple protein) with small quantities of zinc added to the compound. The resulting mixture, a milky suspension, is much less soluble, and is therefore more slowly absorbed in the subcutaneous tissues, than the clear soluble insulin hydrochloride discovered by Banting and Best.2