13C-methacetin breath test shortened: 2-point-measurements after 15 minutes reliably indicate the presence of liver cirrhosis.

BACKGROUND AND GOALS: The 13C-methacetin breath test (MBT) measures the activity of the cytochrome P450 dependent enzyme system and has been developed to assess the functional hepatic mass. We evaluated simple modifications of the 13C-MBT to further increase its practicability and therefore clinical acceptance. STUDY: One hundred and four patients with different chronic liver diseases (including 35 patients with histologically proven cirrhosis) and 65 healthy controls underwent the 13C-MBT. Breath test results of 2-point measurements were compared with conventional breath test results (cumulative recovery after 30 min) and liver histology. RESULTS: The 2-point-measurement at 0 and 15 minutes (with a cut-off <14.6 per thousand delta over baseline) had 92.6% sensitivity and 94.1% specificity in identifying the presence of cirrhosis compared with liver histology. The 2-point-measurements at 5 and 10 minutes also provided good discrimination between cirrhotic and noncirrhotic patients. CONCLUSIONS: The 13C-MBT using 2-point-measurement of breath samples at baseline and after 15 minutes reliably indicates decreased liver function in liver cirrhosis. This simplification of the 13C-MBT will increase practicability and cost efficiency, thus facilitating its clinical acceptability.