title: 13C-Methacetin metabolism in patients with cirrhosis: relation to disease severity, haemoglobin content and oxygen supply.
abstract: BACKGROUND
  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.
  
  
  OBJECTIVE
  We questioned how oxygen supplementation would influence the hepatic microsomal function as assessed by the 13C-methacetin breath test in patients with cirrhosis of different severity and different degrees of anaemia.
  
  
  METHODS
  13C/12C ratios in exhaled breath assessed by non-dispersive infrared spectrometry were studied in 34 patients with cirrhosis (Child A/B/C 9/17/8) after administration of 75 mg 13C-methacetin p.o. with and without oxygen inhalation (4 L/min).
  
  
  RESULTS
  In patients breathing room air the total amount of 13C exhaled weakly correlated both with the Child-Pugh score (r = - 0.41, P < 0.02) and haemoglobin concentrations (r = 0.46; p = 0.006). Oxygen supplementation increased the total amount of 13C exhaled by 68 +/- 90% (P < 0.001). This effect was similar in Child-Pugh classes A (43 +/- 55%), B (83 +/- 80%) and C (66 +/- 123%) and not related to the Child-Pugh score.
  
  
  CONCLUSIONS
  Our results suggest that tests of microsomal liver function are independently influenced both by oxygen delivery and the Child-Pugh score.
authors.affiliation: First Department of Medicine, Martin-Luther-University Halle-Wittenberg, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Zipprich
authors.forename: F
authors.initials: F
authors.lastname: Meiss
authors.forename: N
authors.initials: N
authors.lastname: Steudel
authors.forename: U
authors.initials: U
authors.lastname: Sziegoleit
authors.forename: W E
authors.initials: WE
authors.lastname: Fleig
authors.forename: G
authors.initials: G
authors.lastname: Kleber
mesh_terms: D000081:Acetamides / Q000378:metabolism*; D001944:Breath Tests; D005260:Female; D006454:Hemoglobins / Q000032:analysis; D006801:Humans; D000860:Hypoxia / Q000150:complications / Q000503:physiopathology; D008099:Liver / Q000098:blood supply; D008103:Liver Cirrhosis / Q000378:metabolism* / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D010100:Oxygen / Q000627:therapeutic use*
chemical_list: D000081:Acetamides; D006454:Hemoglobins; C035495:methacetin; D010100:Oxygen