title: Circadian rhythm of fasting and postprandial portal blood flow in cirrhosis.
abstract: OBJECTIVE
  To examine the relationship of both the unstimulated and the postprandial portal blood flow (PVF) to the time of day and to determine its intra-individual reproducibility over time in patients with liver cirrhosis.
  
  
  METHODS
  In 24 cirrhotic patients, 27 PVF measurements were performed during 24 h on day 0 and day 7 using Doppler ultrasound. Three standard liquid meals were given orally. On day 7, the baseline hepatic venous pressure gradient (HVPG) was also measured.
  
  
  RESULTS
  Circadian area under the time curve of PVF was highly reproducible within individuals (r=0.959, p<0.001). It did not correlate with HVPG. Cosinor analysis showed a significant circadian rhythm of PVF (acrophase at 11:44 and amplitude of 9.44%). Maximal postprandial increase in PVF was significantly higher in the morning than at noon or in the evening.
  
  
  CONCLUSIONS
  PVF is subject to a circadian rhythm and postprandial portal hyperemia shows a diurnal variability. Both are highly reproducible.
authors.affiliation: Department of Internal Medicine I, University of Bonn, Sigmund Freud Strasse 25, DE-53105 Bonn, Germany.
authors.forename: Peter
authors.initials: P
authors.lastname: Schiedermaier
authors.forename: Lydia
authors.initials: L
authors.lastname: Koch
authors.forename: Artemio
authors.initials: A
authors.lastname: Mojón
authors.forename: Ramon
authors.initials: R
authors.lastname: Hermida
authors.forename: Günter
authors.initials: G
authors.lastname: Layer
authors.forename: Tilman
authors.initials: T
authors.lastname: Sauerbruch
mesh_terms: D002940:Circadian Rhythm / Q000502:physiology*; D005215:Fasting / Q000502:physiology*; D006801:Humans; D006975:Hypertension, Portal; D008102:Liver Circulation / Q000502:physiology*; D008103:Liver Cirrhosis / Q000378:metabolism*; D019518:Postprandial Period / Q000502:physiology*