Observations on the improvements in carbohydrate metabolism in diabetic and other morbidly obese patients after jejunoileal bypass.

In most morbidly obese patients with diabetes, fasting plasma glucose levels decreased immediately after jejunoileal bypass operations, with patients often becoming normoglycemic before discharge from the hospital. All 12 patients who had required insulin or orally administered hypoglycemic agents preoperatively were able to discontinue the medication shortly after the operation. Oral glucose tolerance test curves in all morbidly obese patients had a flattened pattern, in the normal range, postoperatively. Serum insulin levels, which had been elevated preoperatively, decreased significantly, both in fasting and postglucose determinations. Results of intravenous glucose tolerance tests showed little change in the early period after operation. Improvement in carbohydrate metabolism may be due to several factors and does not appear to be dependent upon massive weight loss. Major factors may include decreased absorption of carbohydrates and amino acids, decreased oral caloric intake, increased insulin sensitivity and decreased output of gastric inhibitory polypeptide as well as the eventual weight loss.