Paraoxonase-1 (PON1) has an anti-oxidative function in preventing the formation of oxidized lipoproteins (LDL and HDL) and hydrolyzing the active metabolites of some organophosphate insecticides (e.g., paraoxon and diazoxon) and other non-physiological substrates. PON1Q192R affects PON1 hydrolytic activity and its protective role against oxidative stress, thereby influencing susceptibility to cardiovascular disease among individuals. The objectives of this study were to determine the effect of race, gender, and age on PON1 activities and PON1192 genotypes in Caucasian and African American Southerners. Serum samples from 200 individuals (equally distributed race and gender classes, ages 25-55) were assayed spectrophotometrically for paraoxon and diazoxon hydrolysis. Data indicate a positive correspondence between PON1192 genotypes and race and PON1 activity and race. Data do not indicate an influence of gender and age on PON1 activities or PON1192 genotypes. These results are useful in explaining the increased risk of cardiovascular disease in African Americans compared to Caucasians

Mississippi has a very high prevalence of coronary artery disease (CAD) and type 2 diabetes (T2D), especially among African Americans compared to Caucasians. This project determined the L55M genotypes of paraoxonase 1 (PON1) in 187 people and evaluated associations of PON1 single nucleotide polymorphisms (SNPs), Q192R and L55M, with CAD and T2D in a Mississippian (southern) population. Significant associations were found with PON1 SNPs and race: genotypes LL, LM, QR, and RR showed significant associations with race (p values 0.0000955, 0.0024, 0.00001244, and 0.00001676, respectively), and combined genotypes LMQQ and LMRR were significantly associated with race (p values = 0.0001013 and 0.000473, respectively). While no significant associations were found between PON1 SNPs and CAD (p values > 0.2374), combined genotype LMQQ and genotype LM trended towards the likelihood of having T2D with p values = 0.0723 and 0.0931, respectively, and are suggestive of a potential biomarker for T2D risk.