[Metabolic changes in patients with hereditary fructose intolerance. A contribution to the topic of fructose administration for parenteral feeding].

The literature contains a number of reports of death following the intravenous administration of fructose in patients with hereditary fructose intolerance (HFI). The aim of the present study was, therefore, to investigate the metabolic changes occurring during intravenous administration of fructose to patients with HFI, with the aim of identifying metabolic parameters that would permit the early diagnosis of HFI. Also, the deaths reported in the literature were analyzed. In three of our own patients with fruit intolerance known since childhood, and in volunteers with normal metabolism, a one-hour intravenous fructose tolerance test (1.7 g fructose/min) was performed. An analysis was done using the usual enzymatic and chemical methods: blood glucose, fructose, lactic acid, serum uric acid, ammonia, free fatty acids, inorganic phosphate, and serum amino acids (ion exchange chromatography). During fructose infusion, the following metabolic changes were detected: hypoglycemia (20 to 60 mg/dl), increase in blood fructose levels (up to 350 mg/dl), hypophosphatemia (2 to 3 mg/dl), hyperlacticacidemia (up to 60 mg/dl), elevation of plasma ammonia levels (up to 120 mg/dl), increased serum glutamate, and a decrease in serum glutamine, as also hyperuricemia (up to 10 mg/dl). On termination of the fructose infusion, these changes were completely reversible. Analysis of the deaths reported in the literature revealed a known intolerance to fruit or sweets, and that no regular metabolic studies were apparently performed. Although HFI is rare, use should be made of the known advantages of sugar substitutes in post-aggression metabolism.(ABSTRACT TRUNCATED AT 250 WORDS)