Factors Affecting Serum Paraoxonase 1 Activity in Migrant and Resident Gujarati South Asians

Paraoxonase 1 (PON1) protects against the development of atherosclerosis by hydrolysing damaging lipid peroxides formed in low-density lipoprotein (LDL) and cell membranes. The effect of migration on PON1 activity is unknown. We have investigated the effect of migration on serum PON1 activity by comparing an Indian Gujarati community who had migrated to Sandwell (West Midlands, UK) with people still living in their villages of origin around the town of Navsari (Gujarat, North-West India) and determined biochemical and nutritional parameters which may correlate with PON1 activity. PON1 activity was almost double in men and women living in Sandwell compared to those in Navsari. In the Spearman’s Rank correlation analysis, PON1 activity was significantly negatively correlated with fasting glucose and C-reactive protein, and positively with fasting non-esterified fatty acids, homeostasis model assessment (HOMA)-insulin sensitivity, and high-density lipoprotein (HDL) in rural Indian men, positively with HDL and apolipoprotein A1 (apo A1) in migrant Indian men, negatively with HOMA-β-cell activity and apo A1. It was positively correlated with HDL cholesterol, mean LDL particle diameter, and oxidised-LDL (ox-LDL) in rural Indian women and positively with HDL cholesterol, apo A1, and ox-LDL in migrant Indian women. Multivariate analysis with PON1 as the dependent variable indicated significant relationships with migrant status and HDL cholesterol only (both p<0.001). In conclusion, in the South Asian populations studied here, PON1 activity significantly correlated with measures of insulin sensitivity and the metabolic syndrome; however, by far the strongest determinant of PON1 activity was migration, or at least environmental and dietary changes which accompany migration. We also found an as yet unexplained lack of gender difference in HDL cholesterol, which requires further investigation.