Hyperoxaluria correlates with fat malabsorption in patients with sprue

The effect of fat malabsorption on the absorption and renal excretion of dietary oxalate was studied in four patients with sprue and in two patients with dermatitis herpetiformis and sprue-like jejunal histology. Hyperoxaluria was present in all patients with sprue when fat malabsorption was severe. Urinary oxalate excretion decreased in two of the three patients with coeliac sprue when their fat malabsorption had improved after three months of dietary gluten restriction. Neither patient with dermatitis herpetiformis and sprue had steatorrhoea. In these patients, urinary oxalate excretion was always within normal limits. A significant positive linear relationship (y=28.25 +4-84x; r=0-82; P less than 0-01) was demonstrated between faecal fat and urinary oxalate excretion. The results of this study support the concept that severe malabsorption of dietary fat plays a primary causative role in enteric hyperoxaluria.