title: Study of liver function in healthy elderly subjects using the 13C-methacetin breath test.
abstract: BACKGROUND
  The issue of whether or not liver function is compromised in the healthy elderly population remains unsolved.
  
  
  OBJECTIVE
  To investigate the putative age-related modifications of hepatic function using the 13C-methacetin breath test. Because endogenous CO2 production changes with age, motor activity and nutrition, a different form of processing the results was investigated.
  
  
  METHODS
  Twenty-nine elderly subjects (mean age, 79.8 +/- 7.9 years; female/male ratio, 17/12) and 28 adult subjects (mean age, 40.6 +/- 12.3 years; female/male ratio, 13/15) underwent 13C-methacetin breath test and trans-abdominal echosonography with Doppler pulsed wave analysis of the coeliac axis and portal vein.
  
  
  RESULTS
  Although the 13CO2 peak occurred within 15-30 min in both elderly and adult subjects, it was significantly decreased in the former (30.66% +/- 9.2% vs. 38.33% +/- 6.05%; P < 0.001), as was the cumulative excretion (33.07% +/- 7.06% vs. 39.81% +/- 5.68%; P < 0.001). When correcting for the effects of CO2 excretion by age, the age-related modification of the cumulative dose became more evident (elderly group 30.15% +/- 6.46% vs. adult group 37.97% +/- 5.92%; P < 0.0001). The elderly group also showed an increase in the intra-hepatic resistance index using Doppler pulsed wave analysis, which inversely correlated with the results of the breath test.
  
  
  CONCLUSIONS
  Hepatic function is not well preserved in healthy humans throughout life and may be due to an increase in vascular resistance.
authors.affiliation: Department of Internal Medicine, University of L'Aquila, Italy. angiologia@rm.unicatt.it
authors.forename: R
authors.initials: R
authors.lastname: Ciccocioppo
authors.forename: M
authors.initials: M
authors.lastname: Candelli
authors.forename: D
authors.initials: D
authors.lastname: Di Francesco
authors.forename: F
authors.initials: F
authors.lastname: Ciocca
authors.forename: G
authors.initials: G
authors.lastname: Taglieri
authors.forename: A
authors.initials: A
authors.lastname: Armuzzi
authors.forename: G
authors.initials: G
authors.lastname: Gasbarrini
authors.forename: A
authors.initials: A
authors.lastname: Gasbarrini
mesh_terms: D000081:Acetamides; D001944:Breath Tests; D002245:Carbon Dioxide / Q000032:analysis / Q000378:metabolism*; D005260:Female; D006801:Humans; D008099:Liver / Q000502:physiology*; D008111:Liver Function Tests / Q000379:methods*; D008297:Male; D013997:Time Factors
chemical_list: D000081:Acetamides; C035495:methacetin; D002245:Carbon Dioxide