Background: Paraoxonase1 activity shows decline in patients with coronary artery disease. The C to T change in the -107 position of promoter is the most important genetic determinant of serum levels of paraoxonase 1. Study of this polymorphism and its relationship with the type of fatty acid composition of phospholipids in HDL particles can be found in the common pursuit of better medicines and considered in drug treatment.

Materials and Methods: In this descriptive study 265 Patients were selected and divided in two groups based on LDL level (131 in case and 134 in control). Information of subjects were collected from questionnaire and the results of biochemistry and molecular tests. Fatty acids of HDL phospholipids were measured with Gas chromatography technic .

Results: PON1aryl esterase activity, had no significant changes after treatment with lovastatin but paraoxonase activity had more significant increases in the CC genitype of -C/T107 polymorphism. Percent of oleic acid, linoleic acid and icosapentanioc acid in HDL phospholipids were increased by lovastatin.

Conclusion: Treatment with lovastatin in the CC genotype is probably more protective effect against cardiovascular disease. Following treatment, in patients with higher paraoxanase 1 activity Oleic acid and linoleic acid have also increased in HDL phospholipids.