Insulin release in hyperuricemic patients

The insulin response to oral glucose and to i.v tolbutamide was stuied in a group of hyperuricemic subjects and in a group of weight-matched controls. Glucose tolerance was impaired only in obese hyperuricemic subjects. Insulin response to oral glucose was enhanced in hyperuricemic subjects. Tolbutamide gave rise to a sharp increase in IRI levels already 2 min after the injection and this rise was significantly higher in hyperuricemic subjects than in controls. The same result was observed also after i.v. fructose. The interpretation of these data is not easy. Uric acid plasma level and obesity do not seem to be directly involved because an abnormal IRI response has been observed also after a rapid fall in uric acid plasma level after allopurinol treatment and is evident also in lean subjects. In our opinion the problem is more complex and must be considered from the point of view of a change involving carbohydrate as well as purine metabolism.