Endocrine Abstracts

Aim: Paraoxonase-1 (PON-1), an HDL-associated enzyme has been shown to possess antioxidant properties that protect against atherosclerosis. The aim of this study is to evaluate serum paraoxanase activities, lipid profiles and carotid intimae media thickness (CIMT) as an early marker of atherosclerosis in healthy man and women.

Method: Four hundred healthy volunteers (F/M: 250/150, 19–23 years) included in the study. Serum paraoxonase and arylesterase activities, lipids and Apo a levels were measured. CIMTwas evaluated with Doppler ultrasonography.

Results: Biochemical parameters are shown at the Table 1.

CIMT measurement was significantly higher in man (0.460±0.02 cm) compared to women (0.450±0.02 cm, P=0.006). Body mass index was lower in women (20.8±3.4 kg/m²) than man (23.5±4.1 kg/m²) (P<0.001). Serum paraoxonase activity was positively correlated with arylesterase (r=0.31, P<0.001) and HDL levels (r=0.14, P=0.03), negatively correlated with CIMT (r=−16, P=0.03) in women. Arylesterase activity was positively correlated with HDL levels (r=0.14, P=0.04) in women. In men paraoxonase activity showed significant correlation with arylesterase activity (r=0.20, P<0.01) but not with CIMT.

Conclusion: A Serum PON-1 activity varies between young man and women. PON-1 activities against different substrates and mass of the enzyme need to be studied for antioxidant properties of PON-1 enzyme.