Paraoxonase (PON 1) polymorphism & its relation with lipids in north west Indian Punjabis

We investigated 190 healthy, unrelated and randomly selected, north-west In dian Punjabis (M:102; F:88) for paraoxonase (PON1) polymorphism by dual sub strate method and also determined lipid variables i.e., total cholesterol ( TC), high density lipoprotein cholesterol (HDL), low density lipoprotein ch olesterol (LDL) and triglycerides (TG) in them to determine any relationshi p between PON1 activity, PON1 phenotypes and lipids. The basal plasma parao xonase (PON) activity, and PON activity in presence of 1 Mol NaCl (salt act ivated paraoxonase i.e., SAP) were estimated by using paraoxon as substrate whereas the, phenyl acetate esterase (A) activity was estimated by using p henylacetate as substrate. Based on the ratio of SAP / A activity, three di stinct phenotypes of PON1 could be determined with gene frequencies of PON* A (low activity) and PON*B thigh activity) allele being 0.847 and 0.153 res pectively. In the whole population on partial correlation after normalising the variables and after adjusting the lipids for age and body mass index ( BMI), a significant negative correlation was observed between SAP /A ratio and TC (r= -0.290; P<0.01) and LDL (r=-0.154; q<0.05). However, on analysis of covariance (ANCOVA) after normalising the lipid variables and adjusting these for age and body mass index (BMI), no significant difference could b e observed in lipid profile of these three phenotypes. The lack of a signif icant relationship between lipids and PON1 phenotypes, suggests that PON ph enotype does not significantly influence the lipid profile in north-west In dian Punjabis. However, a significant negative correlation between the PON activity and TC and LDL suggests that low PON activity could be a risk fact or for atherosclerosis in these subjects.