Certain diabetic patients receiving insulin in amounts of 70 to 150 U. daily exhibit “insulin resistance” to a demonstrable degree. The diminished response to a specific dose of insulin, which is the criterion for such resistance, is related to the species source of the insulin used.
Eleven patients whose daily insulin requirements were in a dose range not uncommonly encountered in clinic practice were studied. Insulins which were derived from various species or which had been structurally altered (dealaninated) were utilized. Six of the patients were shown to manifest definite improvement in their diabetic state when a change was made from beef insulin to pork insulin, dealaninated insulin (pork), or human insulin. The improvement was characterized by a drop in blood glucose, a lowering in daily insulin requirement, or both. One patient of the eleven gave equivocal results and four showed no evidence of improvement.
Although the patients' sera were not examined for the presence of insulin-binding antibodies and thus no positive evidence for the presence of species-related differences in antibody titer can be offered, it appears that a diminished response to insulin, if observed, is most commonly associated with the injection of insulin derived from beef pancreas. Also, it is noted that the more closely the amino acid sequence of the insulin used approximates that of human insulin, the less the interference and the better the hypoglycemic response.
