13C-aminopyrine demethylation is decreased in cirrhotic patients with normal biochemical markers

• Published in: Isotopes in environmental and health studies Vol. 49; no. 3; pp. 346 - 356
• Main Authors: Afolabi, Paul, Wright, Mark, Wootton, Steve A., Jackson, Alan A.
• Format: Journal Article
• Language: English
• Published: England Taylor & Francis 2013
• Subjects: administered dose; Adult; alanine transaminase; alkaline phosphatase; Aminopyrine - metabolism; bilirubin; biochemical markers; biomarkers; Biomarkers - metabolism; Breath Tests; C-aminopyrine breath test; Carbon Isotopes - metabolism; carbon-13; Child-Pugh score; cirrhosis; Female; Finland; health; hepatic function; human; Humans; isotope application in medicine; liver cirrhosis; Liver Cirrhosis - etiology; Liver Cirrhosis - metabolism; Liver Function Tests; Male; metabolism; Methylation; Middle Aged; patients; stable isotope tracer techniques; stable isotopes; Young Adult; Finland
• ISSN: 1477-2639; 1025-6016; 1477-2639
• DOI: 10.1080/10256016.2013.803098

This study determined the rates of ¹³C-aminopyrine metabolism in patients with varying degrees of liver cirrhosis as defined by clinical scores. Twenty-five cirrhotic patients and 18 healthy subjects underwent a ¹³C-aminopyrine breath test. The cumulative per cent dose recovery (cPDR) of ¹³C on breath expressed as a percentage of the administered dose at 2 h was significantly lower in cirrhotic patients than in healthy subjects (median: 1.7% versus 9.0%; p <.0001). Significant inverse associations between cPDR at 2 h and the model for end-stage liver disease score, Child–Pugh score, international normalised ratio and bilirubin (all p <.05), but not alanine aminotransferase or alkaline phosphatase were observed in the cirrhotic patients. Taking each biochemical marker independently, cirrhotic patients with normal biochemistry had a significantly lower cPDR at 2 h than healthy subjects (all p <.05). Differences in ¹³C-aminopyrine metabolism were evident in cirrhotic patients with less severe disease and may mark hepatic dysfunction when conventional biochemical markers appear unchanged.