THE METABOLISM OF RIBOFLAVIN IN FEMALE-PATIENTS WITH LIVER-CIRRHOSIS

The metabolism of vitamin B-2 was studied in five female patients with liver cirrhosis of varying etiology. Following the oral administratio n of 40 mg(106.3 mu mol) riboflavin, plasma concentrations of riboflav in excretion were analyzed over a period of 48 h. Results were compare d to data obtained for healthy controls (Zempleni J. et al, Am. J. Cli n. Nutr., 1996 [15]). About 18% of the administered vitamin was recove red from patients' urine, indicating an absorption similar to healthy subjects (p >0.05). The area under the riboflavin plasma concentration vs time curve was 1.2-fold larger among patients than controls, but t he difference was not significant (P >0.05). Riboflavin peak concentra tions in plasma (315.6 nmol/l) and times when those concentrations wer e achieved (3.0 h) were similar to those found for healthy subjects (p >0.05). Flavocoenzyme peak plasma concentrations were increased 1.4-f old above their baseline levels in cirrhotics which was equal to contr ols (p >0.05). 7 alpha-Hydroxyriboflavin was detected in the plasma of patients. Distribution and elimination kinetics of riboflavin were an alyzed by using a two-compartment open model; the riboflavin plasma di sposition rate constants of the patients (k(alpha)=0.7232 h(-1); k(bet a)=0.0627 h(-1)) were not different from controls (p >0.05). No differ ences between both groups were found regarding renal excretion (renal clearance, first-order rate constants for renal excretion; p >0.05). I n conclusion, patients with liver cirrhosis of varying etiology and va rying medical treatment did not show alterations of riboflavin turnove r.