Age-related paraoxonase activity changes in Turkish population.

Paraoxonase1 (PON1) is a high-density lipoprotein (HDL)-associated enzyme capable of hydrolyzing diverse substrates from organophosphate (OP) toxins to oxidized phospholipids. As such, it has been linked with both the prevention of OP poisoning and inhibition of atherosclerosis initiated by oxidatively modified low-density lipoprotein (LDL). The aim of this study was to investigate, with aging, the activity of PON1 associated with HDL and partially responsible for its antiatherogenic activity. The study involved 187 individuals (67 males and 120 females) divided into three groups according to their ages, young (n = 49; 20-44 years, mean age = 30.12 +/- 6.6 years), middle aged (n = 25; 45-64 years, mean age = 52 +/- 5.6 years), and elderly subjects (n = 113; 65-95 years, mean age = 78.94 +/- 6.2 years). Interestingly, serum total cholesterol and LDL-cholesterol levels significantly decreased with age (P < 0.05). The elderly aged group had also significantly lower body mass index than the middle aged group (P < 0.05). Serum paraoxonase activity and HDL cholesterol levels remained unchanged with age. The prevalence of phenotype AA, AB, and BB in our subjects' group was 40.6%, 45.9%, and 13.5%, respectively.