The plasma clearance of fructose and glucose during and after surgical operation.

Fasting blood glucose is elevated and the rate of disappearance of a glucose load is reduced after major surgery. Resistance to insulin is considered to play a part in post-traumatic glucose intolerance. Fructose metabolism is partly independent of insulin. Glucose and fructose clearance were compared in two groups of 6 matched male patients with normal glucose tolerance who were studied before and after major vascular surgical operations of the same severity. Fructose or glucose (25 g) was given intravenously over a 2-min period before, during and at intervals for 8 days after surgery. The rate of clearance of fructose increased significantly during operation (P less than 0.01), but returned to the preoperative level by the first postoperative day. Glucose clearance, in contrast, was reduced during and throughout the 8 days of the study. The fructose load produced a brisk insulin response before operation which was diminished and delayed during surgery. These findings suggest that administered fructose may be removed more rapidly than glucose during and immediately after surgical operation.