Evaluation of lipid profile and oxidized LDL levels among different paraoxonase phenotypes in exudative age-related macular degeneration

Disequilibrium between oxidative stress and antioxidant levels has been proposed as an important case of exudative age-related macular degeneration (ARMD). The aim of the present study was to investigate lipid profile and oxidized low-density lipoprotein (OX-LDL) levels within paraoxonase 1 (PON1) phenotypes together in the patients with exudative ARMD.
Of 90 patients, 45 exudative ARMD patients and 45 healthy controls were selected by an ophthalmologist. PON1 activity was measured in serum using paraoxon and phenylacetate as substrates. The PON1 phenotype was determined using double-substrate method. Cholesterol, triglyceride and HDL were assayed by colorimetric method. OX-LDL levels were determined by enzyme-linked immunosorbent assay method.
Three phenotypes were determined: AA (low activity), AB (intermediate activity) and BB (high activity). The distribution of PON1 phenotypes was significantly different between the patients with exudative ARMD and control subjects (chi-square = 6.17, P= 0.01). The mean OX-LDL levels in all three phenotypes (P Increased plasma OX-LDL levels and ratios of OX-LDL/ HDL, as biomarkers of lipoprotein oxidative stress and more common low or intermediate PON1 activity in patients with exudative ARMD, indicate that PON1 activity is insufficient to explain the increased oxidative stress observed in exudative ARMD.