Aim To evaluate effects of the G994T,sex,and age on the lipoprotein-Associated phospholipase A2(Lp-PLA2) activity.Methods Genotyping of the G994T was done by the allele-specific PCR.The Lp-PLA2 activity was measured using a commercial kit by the spectrophotometric method.Results The Lp-PLA2 levels were significantly higher in GG subpopulation,as compared to GT population and TT population.The Lp-PLA2 activity was correlated with sex.We found that,in men with the GG genotype,enzyme activity increased significantly with age.In contrast,plasma Lp-PLA2 activity in men with the GT genotype did not significantly increase with age.Conclusions The G994T was strongly correlated with the enzyme activity.The Lp-PLA2 activity in men was higher than that in women.Plasma PAF-AH activity may increase in response to stresses induced by PAF and:or oxidized phospholipids.This compensatory response may be attenuated or not evident in individuals with the m allele.