Impaired vitamin E status in patients with parenchymal liver cirrhosis: relationships with lipoprotein compositional alterations, nutritional factors, and oxidative susceptibility of plasma.

Vitamin E is a lipid-soluble vitamin and an important antioxidant that protects lipoproteins and cell membranes from lipid peroxidation. The aims of the present study were to investigate, in patients with parenchymal liver cirrhosis, the following: (1) nutritional and vitamin E status in relation to compositional changes in lipoproteins; and (2) the effects of these alterations on the patients' plasma susceptibility to copper-mediated oxidation. Patients (n = 55) with liver cirrhosis and 25 healthy volunteers had vitamin E in serum and in isolated lipoprotein fractions analyzed by high-performance liquid chromatography (HPLC). Plasma susceptibility to peroxidation was measured by incubation with Cu(2+). Nutritional status was assessed by anthropometry. Vitamin E concentration was significantly decreased (P <.001) in the serum and in very-low-density lipoprotein (VLDL) and high-density lipoprotein (HDL) in cirrhotic patients. The decrease was related to the degree of liver impairment. There were significant correlations between cholesterol and vitamin E concentrations in serum and in all the lipoprotein fractions (r between 0.72 and 0.89; P <.001) in cirrhotic patients, but there were no significant relationships between vitamin E and any of the anthropometric indices of nutritional status. The plasma maximal oxidation rate was significantly increased in cirrhotic patients (P <.01) and was inversely related to the serum concentration of vitamin E (P <.05). We conclude that lipoprotein alterations and not nutritional factors should be regarded as major factors explaining serum vitamin E reduction in patients with parenchymal liver cirrhosis, and that vitamin E depletion is associated with an increased plasma susceptibility to oxidation.