Normalization of the insulin sensitivity and the cellular insulin binding during treatment of obese diabetics for one year.

The relative importance of the insulin resistance, the decreased cellular insulin binding and the relative insulin deficiency in the pathogenesis of diabetes mellitus in obese subjects has been studied. Ten obese diabetics were studied before and during treatment for 1 year with a 1200-1500 kcal's diet. No change was found in the insulin response to iv injection of glucose during treatment (P greater than 0.1), whereas the insulin sensitivity was normalized after 1 year (P less than 0.01). In parallel to the clinical normalization and the improvement of the insulin sensitivity the insulin binding to monocytes was normalized (P less than 0.01). We conclude that both the insulin resistance and the relative insulin deficiency are of decisive importance in the pathogenesis of diabetes mellitus of the obese. The insulin receptor defect seems to be one of the major factors responsible for the insulin resistance.