A Comparison of the Oral Fructose and Ammonia Tolerance Tests in Cirrhosis

To estimate portal systemic collateral circulation and portal hypertension, results of the fructose and ammonia tolerance tests were compared in 23 patients with cirrhosis. There was good correlation between the arterial ammonia and venous fructose values (r =+0.80). The ability of the fructose tolerance test to separate patients with mild from those with severe cirrhosis was statistically significant (P <0.01). Mean values for peak serum fructose were 23.3 ± 3.2 mg per 100 ml (± 1 SE) in patients with mild cirrhosis and 41.3 ± 4.4 mg per 100 ml in patients with severe cirrhosis. There was no correlation between abnormal results of fructose tolerance tests and demonstration of esophageal varices by roentgenogram taken after barium swallow. This test also failed to separate patients with surgical portacaval shunts from other cirrhotic patients. The fructose tolerance test (fructose given orally) appears to be a safe, practical substitute for the more difficult