Effect of valvular aortic stenosis on insulin sensitivity.

18 patients with valvular aortic stenosis were given an i.v. glucose tolerance test and an i.v. insulin tolerance test before and 4-36 months after valve replacement. Insulin and C-peptide response to the glucose challenge was smaller preoperatively whereas the glucose response was the same pre- and postoperatively. The effect on blood glucose of the i.v. insulin challenge was more pronounced preoperatively. It is concluded that insulin sensitivity was increased preoperatively and it is suggested that this was a metabolic adaptation to the haemodynamic situation in aortic stenosis, which may have implications for preoperative glucose-insulin-potassium treatment.