Increased plasma homocysteine in liver cirrhosis

Background: Homocysteine (Hcy), is an atherogenic and thrombogenic risk factor which has also been proposed to be involved in hepatic fibrinogenesis. Hey metabolism depends on the cofactors folate, vit. B12, and the vit. B6 vitamer pyridoxalphosphate (PLP). Metabolism of these vitamins is frequently disturbed in cirrhotics, but little is known about plasma Hey levels in these patients. Methods: Plasma le levels of Hcy, methionine, serine, cysteine, PLP, vit. B12 and folate, and standard clinical/biochemical parameters of liver disease were measured in 43 postabsorptive patients with biopsy proven cirrhosis of different origin. Results: 74% of the patients had elevated plasma Hey levels defined as > 13.4 mu mol/l (mean + 2SD of healthy age matched controls). Increased plasma Hcy concentrations were seen in alcoholic as well as in non-alcoholic cirrhosis. Excluding patients with impaired renal function (n = 7), Hey concentrations remained elevated in 69% of the patients. We found a high prevalence of pathological plasma vitamin concentrations of 33% for increased vit. B12 levels and 5% and 80% for decreased folate and vit. B6 levels, respectively. Mean plasma vitamin B12 concentrations increased, folate remained unchanged and PLP concentrations decreased with deteriorating liver function. Hey concentrations were correlated with levels of creatinine (r = 0.44, P < 0.01), serine (r = -0.46, P < 0.01), and cysteine (r = 0.38, P < 0.05), but showed no association with parameters of liver function and with plasma levels of folate, vit, B12 und vit. B6. This was contrary to data obtained in healthy individuals. In a stepwise multiple regression serine and cysteine best explained the variance in Hey levels. Conclusions: Elevated basal Hey-plasma levels are frequently seen cirrhotic patients. Variations of Hey concentration in liver cirrhosis are not explained by plasma levels of cofactors of Hey metabolism. <(c)> 2001 Elsevier Science Ireland Ltd. All rights reserved.