High-density lipoprotein cholesterol and paraoxonase 1 (PON1) genetics and serum PON1 activity in prepubertal children in Spain

BACKGROUND: Oxidative stress plays an important role in atherosclerosis. Paraoxonase 1 (PON1) is a high-density lipoprotein (HDL)-associated enzyme that inhibits low-density lipoprotein (LDL) oxidation and may play a protective role against coronary heart disease. The aim of this study was to analyze the relationship between HDL-cholesterol (HDL-C) and PON1 in a Spanish prepubertal population with high plasma HDL-C levels. METHODS: The study population included 1,266 children between the ages of 6 and 8 years. Serum PON1 activity was measured by the hydrolysis of paraoxon. PON1 192Q/R and PON1 55L/M polymorphisms were analyzed by PCR and restriction analysis. RESULTS: The prevalence of the less common PON1 192R and PON 55M alleles in this population was 30% and 38%, respectively. No significant correlations between serum PON1 activity and lipid profile were observed. Multiple linear regression analysis showed that the PON1 192Q/R polymorphism accounts for 69% of PON1 activity in the children in the study, with the PON1 55L/M polymorphism accounting for an additional 5% of this variation in boys, and for an additional 3% together with HDL-C concentration in girls. CONCLUSIONS: PON1 192Q/R polymorphism is the main determinant of PON1 activity in the prepubertal population in this study, accounting for around 70% of serum PON1 activity. HDL-C concentration has a small contribution to serum PON1 activity in girls.