The relationship between leisure-time exercise and lipid profiles is affected by Q192R polymorphisms of paraoxonase-1 among Japanese women

INTRODUCTION: Paraoxonase-1(PON-1) is an antioxidant enzyme which protects against lipid peroxidation by destroying proinflammatory molecules formed by the oxidation of LDL-cholesterol. Previous studies demonstrated that PON-1 polymorphism, rs662 (Q192R) affects the development of such life-related diseases as ischemic stroke and chronic kidney disease. In addition, some environmental and lifestyle factors are likely to modify the effect of this SNP. In this study, we aimed to examine the effect of PON-1 polymorphisms on the relationship between leisure-time exercise and lipid profiles. 

METHODS: Subjects were 5070 (1439 men and 3631 women) individuals who were enrolled in the baseline survey at a site of the Japan Multi-Institutional Collaborative Cohort Study (J-MICC Study). We used the OPA-CTPP method, an inexpensive and convenient method, for genotyping single nucleotide polymorphism (SNP). We classified the subjects into two groups based on leisure-time exercise (MET-hour per week). We used the χ² test to confirm the Hardy-Weinbarg equilibrium and linear regression analysis to investigate the interaction effect between PON-1 polymorphisms and exercise on lipid profiles after adjusting for some confounders. 

RESULTS: The mean age was 52.5±10.3. The genotype frequencies for Q192R are A/A:573 (11.3%), G/A:2303 (45.4%) and G/G:2194 (43.3%), respectively. The proportion of Q192R genotype was in accordance with previous studies. When the interaction between lifestyle and Q192R was evaluated, the effect of exercise on HDL-C levels (p=0.02) and TG levels (p=0.03) was significantly affected by PON-1 polymorphisms in women, indicating a sharp contrast among those with A/A genotype. However, such relationships were not observed in men. 

CONCLUSIONS: Our study shows that improvement in lipid profiles by leisure-time exercise is more prominent among women with Q192R A/A genotype than others. It will be necessary to examine the influence that PON-1 polymorphisms confer for the association between other lifestyle factors and lipid profiles in the future study.