AJP - Regulatory, Integrative and Comparative Physiology, Vol 240, Issue 5 266-R271, Copyright © 1981 by American Physiological Society
A modeling study of the effect of fasting on bilirubin kinetics in Gilbert's syndrome
L. Okolicsanyi, R. Orlando, M. Venuti, G. Dal Brun, C. Cobelli, A. Ruggeri and A. Salvan
The mechanism of fasting hyperbilirubinemia (FH) is not fully understood.
We investigated basal bilirubin kinetics in 20 Gilbert's patients and in 7
healthy volunteers. The study was repeated in seven of these Gilbert's
patients after 48-h fasting. A two-compartment model proved to be adequate
for interpreting crystalline bilirubin kinetics in these individuals. The
parameters of bilirubin kinetics were estimated by employing a maximum
likelihood parameter estimation technique. Consistency of the model and
uniqueness of the estimated parameter values (from the covariance matrix)
were shown. Our results confirmed previous observations regarding impaired
bilirubin kinetics in Gilbert's patients as compared to controls. The main
results obtained from kinetic studies in Gilbert's patients after fasting
were i) no modification in the bilirubin clearance, and ii) a more than
twice increase of bilirubin turnover. These data indicate that FH is
related to an increased bilirubin production (mainly intrahepatic).
Furthermore, evidence arises from this study that the bilirubin tolerance
test is a useful diagnostic test for Gilbert's syndrome.
