[Fructose tolerance and utilization in healthy and chronically diseased liver]

In 12 patients with liver cirrhosis (LC) and 11 normal subjects (N) equimolar (0.75 g/kg/h for 4 hrs.) 14C-(1)-glucose and 14C-(1)-fructose infusions were administered. When given fructose, N and LC showed only a small increase of serum-glucose and -fructose concentrations in steady state. In N and LC the total fructose clearance was significantly higher than the total glucose clearance. No differences were found between N and LC. The metabolic clearance was equal in both groups when given fructose, whereas during glucose infusion lower in LC than in N. 30% of the infused 14C-fructose were recovered in 14C-glucose. The renal loss in both groups was higher for glucose than for fructose. A more extensive renal 14C-excretion during infusion of 14C-fructose was due to a higher 14C-lactate excretion.