Absorption and metabolism of D(–) fructose in man

Abstract

Fructose has been incriminated in the etiology of human arterial disease. To search for a possible individual variation in its absorption products, oral fructose (50 g) was given to 19 subjects without liver disease, 5 of whom had ischemic disease (the normal group) and to 10 with proven cirrhosis. Sixteen of them were also given oral glucose (50 g) on another occasion. Blood fructose, glucose, pyruvate, lactate, insulin, and triglyceride-glycerol concentrations were measured by specific methods before and at intervals during the 2 hr after the sugar was given. There is no evidence of gross differences in the absorption products of fructose in man, although, as expected, there are individual variations in blood glucose and lactate concentrations. The blood biochemical changes in the subjects with ischemic cardiac disease were not significantly different from the other subjects in the normal group. The blood glucose and insulin curves after fructose were similar in all subjects, and both were significantly flatter than the curves after glucose. Blood pyruvate and lactate concentrations were also similar in different individuals, although there was a much wider scatter in the results and the curves were significantly higher after fructose than after glucose. There was a very wide variation in the blood triglyceride-glycerol concentrations after fructose. Although the mean blood fructose curve in the cirrhotic patients was significantly higher than in the normal group, more than one-half of the cirrhotic patients had curves that were similar to those in the normal group. The highest curves were in patients with proven portal-systemic shunting.