¹³C‐Methacetin metabolism in patients with cirrhosis: relation to disease severity, haemoglobin content and oxygen supply

Abstract

SUMMARYBackground: Hypoxia may contribute to impairment of liver function and thus interfere with results of liver tests. In patients with cirrhosis, cytochrome P-450 mediated metabolism of substrates is facilitated in the presence of supplemental oxygen. It has not been studied how this relates to liver function and haemoglobin content. Aim: We questioned how oxygen supplementation would influence the hepatic microsomal function as assessed by the 13 C-methacetin breath test in patients with cirrhosis of different severity and different degrees of anaemia. Methods: 13 C/ 12 C ratios in exhaled breath assessed by non-dispersive infrared spectrometry were studied in 34

13C-methacetin breath test reproducibility study reveals persistent CYP1A2 stimulation on repeat examinations

“…Remarkably, as opposed to the short gap between consecutive examinations, the capacity of the liver to handle 13 C-methacetin increased slightly but statistically significantly when a repeat dose was administered after two to three weeks.…”

“…Neither the time gap between the repeat examinations nor the gender of the subjects affected the 13 C-MBT reproducibility.…”

“…The reproducibility of the 1-h cumulative 13 C recovery (AUC0-60), characterized by a coefficient of variation of 10%, appeared to be considerably better than the reproducibility of the maximum momentary 13 C recovery or the time of reaching it. Remarkably, as opposed to the short gap between consecutive examinations, the capacity of the liver to handle 13 C-methacetin increased slightly but statistically significantly when a repeat dose was administered after two to three weeks.…”

“…13 C-MBT is most reproducibly quantified by the cumulative 13 C recovery, but the exactitude thereof may be modestly affected by persistent stimulation of CYP1A2 on repeat examinations.…”

“…A brilliant idea of per oral administration of 13 Cenriched substrates in order to get information on the metabolic efficiency or functional mass of the liver is a…”