14C-D-galactose breath test for evaluation of liver function in patients with chronic liver disease.

D-Galactose metabolism and demethylation of aminopyrine by healthy controls and patients with chronic active hepatitis (CAH) and cirrhosis (Ci), were assessed by a breath analysis technique measuring 14CO2 exhalation after oral ingestion of 14C-D-galactose or 14C-aminopyrine. Patients with CAH and Ci exhibited decreased 14CO2-exhalation rates following 14C-D-galactose or 14C-aminopyrine. D-Galactose oxidation capacity of the liver can be assessed by a breath analysis technique in analogy to the demethylating function for aminopyrine. The ordinary oral D-galactose tolerance test seems, however, superior in comparison to the 14C-D-galactose tolerance test, in discriminating between healthy controls and patients with chronic liver disease.