Study of the paraoxonase and platelet-activating factor acetylhydrolase activities with aging.

The purpose of this study was to investigate, with aging, the activity of two enzymes associated to HDL and responsible for its anti-atherogenic activity; paraoxonase (PON1) and platelet-activating factor acetylhydrolase (PAF-AH). Ninety-five subjects aged between 26 and 77 years were recruited for the study. The prevalence of phenotype A, AB, and B in our subjects group was 69.47,21.05 and 9.47% respectively. Plasma as well as HDL paraoxonase activity decreased significantly with aging (r =-0.218, P < 0.039) and (r = -0.280, P < 0.006) respectively. PAF-AH activity was unchanged with aging however, we noted a negative correlation between PAF-AH and PON1 activity in HDL (r = -0.243, P < 0.02) and in LDL vs HDL (r =-0.462, P < 0.001).