Serum PON1 activity and oxidative stress in non-alcoholic fatty liver disease

Background: Recent studies have shown that non-alcoholic fatty liver disease (NAFLD) is associated with increased carotid intima-media thickness as a reliable marker of early atherosclerosis, but possible direct relationships between NAFLD and carotid artery atherosclerosis is unknown. Therefore, the aim of this study was to investigate serum paraoxonase and arylesterase activities (PON1) along with lipid hydroperoxide (LOOH) levels. Methods: We studied 32 consecutive patients with biopsy proven NAFLD and 28 healthy controls. Serum basal/saltstimulated paraoxonase and arylesterase activities were detected spectrophotometrically. LOOH levels were measured by the FOX–2 assay. Results: Serum basal/salt-stimulated paraoxonase and arylesterase activities were significantly lower in NAFLD than controls (p<0.05, p<0.05, p<0.05; respectively), while LOOH levels were significantly higher (p<0.05). Conclusions: These results suggest that NAFLD are associated with increased oxidative stress and decreased PON1 activity. Thus, low serum PON1 activity could contribute to, in part, pathogenesis of carotid arterial atherosclerosis in patients with NAFLD.