SERUM PARAOXONASE ACTIVITY AND ITS RELATION TO SERUM LIPIDS IN CORONARY ARTERY DISEASE.

CORRESPONDING AUTHOR:
Dr. Rakhi S. Nair,
Assistant Professor,
Department of Biochemistry,
Govt. Medical College,
Thiruvananthapuram-695011.
E-mail: rakhiniranjan@gmail.com

ABSTRACT: Human serum paraoxonase1 (PON1) is a calcium dependent esterase enzyme that hydrolyses lipid peroxides accumulating on low density lipoproteins. In the serum, PON1 enzyme is almost exclusively located on the high density lipoprotein (HDL). It hydrolyses oxidised lipids in low density lipoprotein (LDL) and could therefore retard the development of atherosclerosis. As PON1 activity has a role in preventing atherosclerosis and coronary heart disease is common in Kerala, this study was conducted to assess the activity of the enzyme and its corelation to serum lipids. MATERIALS AND METHODS: In this case-control study, one hundred patients with coronary artery disease and one hundred healthy controls were included. Serum paraoxonase activity was meausured using phenyl acetate as substrate and lipid profile was done in auto analyzer. RESULTS: The mean PON 1 activity {(70.21±27.62) in cases against (135.86±33.48) in controls (p value .000)} was significantly low in CAD group compared to the control group. The CHD group had a significantly lower mean total cholesterol level (202.82±57.77 against 219.45±46.08) and lower mean HDL level (40.88±10.08 against 56.79±17.24). Correlation of the activity of PON1 with other variables for the combined group (Cases and controls taken together) showed that age is negatively correlated and HDL is positively correlated with PON 1 activity. CONCLUSIONS: The activity of serum paraoxonase enzyme (PON1) is low in patients with coronary artery disease compared to healthy controls. Thus low serum PON1 enzyme activity is a risk factor for CAD. The activity of the serum PON1 enzyme increases with increase in HDL level and decreases with increase in age for the combined group.

KEYWORDS: paraoxonase, cardiovascular, atherosclerosis