Impaired glucose tolerance: a late effect of insulin shock treatment.

Glucose tolerance tests were performed in a group of patients in a mental hospital who had been treated with insulin shock and in a matched control group. Five out of 31 (16%) patients in the insulin-treated group and 1 out of 22 (5%) controls had "diabetic" blood sugar curves. Median blood sugar values were significantly higher at 60 minutes and later in the insulin-treated group, as were mean blood sugar values when the "diabetic" patients were excluded. Small amounts of plasma insulin-binding antibody were found in two insulin-treated patients. In the absence of any other clear-cut explanation, it is suggested that in some patients massive doses of insulin by injection may leave diminished tissue responsiveness to insulin as a long-term after-effect.