RESUMEN
In this study we investigated the relationship between vitamin D and markers of oxidative stress and apoptosis in patients with liver cirrhosis stratified according serum GGT activity. Forty-eight patients with liver cirrhosis of various aetiology were selected, among which 58% cases (n=28) diagnosed with alcoholic liver cirrhosis and 42% (n=20) with cirrhosis after hepatitis virus infection. Each group was divided into three quartiles according GGT activity. 25-hydroxyvitamin D [25-(HO) vit D], markers of oxidative stress (catalase, superoxide dismutase) and apoptosis (M30) were compared. Higher levels of GGT were correlated with elevated AST, ALT and ALP values in both groups. A statistically significant difference was observed when comparing 25-(OH) vit D levels of patients suffering from ethanol-induced liver cirrhosis versus control group for all the quartiles as well as for those from the first quartile of viral-induced liver cirrhosis. For SOD, statistically significant differences were noticed between all cirrhosis subgroups and the control group. CAT values in all cirrhosis subgroups were lower than in control, but significant differences were only between Q2.2 and Q1.3 quartiles and Q2.2 and control. Correlation of 25-(OH) vit D versus SOD yields statistically significant results in ethanol-induced cirrhosis patients. M30 activity was increased in patients with alcoholic cirrhosis compared to controls and those with virus-induced cirrhosis, being correlated with the degree of GGT activity. Our results emphasized that vitamin D deficiency is associated with enhanced liver dysfunction regardless of the trigger responsible for disease onset. Furthermore, vitamin D deficiency augments liver injury by promoting oxidative stress which influence the survival mechanisms of parenchymal liver cells.
RESUMEN
Oxidative stress involvement in liver diseases has been extensively studied. A direct assessment of the reactive species incriminated is avoided due to their short lifespan and high cost. For these reasons an inexpensive and easy to perform test for whole body oxidative stress is highly desired. This pilot study was conducted to assess the relationship between γ-glutamyl transferase (GGT) activity and markers of oxidative stress: reduced glutathione (GSH), glutathione peroxidase (GPx) activity and lipid peroxidation in patients with liver cirrhosis due to chronic ethanol consumption and viral hepatitis. Forty-eight patients with alcoholic liver cirrhosis and cirrhosis developed after HBV and HCV infection were included in this study.Blood GSH andGPxand serum GGT and MDAwere assayed and the results were statistically analyzed. The activity of serum GGT was significantly higher in the alcoholic group. The relationship between GGT activity, GSH and MDA levels was different between groups.A strong significant positive correlation between GGT and GSH was noticed for the patients from GGT Q3 and Q4 quartiles in the group of viral liver cirrhosis, while for alcoholics the relationship between GGT and GSH showed the trend for a negative correlation.The values of serum MDA differ significantly between groups (p<0.015); a very significant variation was observed at low levels of GGT activity (p<0.006). Our study demonstrates that the GSH antioxidant defense system is more compromisedin alcoholic cirrhosisand tends to correlate negatively with GGT. Even in its normal range GGT might be an early and sensitive marker of oxidative stress.