RESUMEN
PURPOSE: Genetic polymorphisms in antioxidant defense and detoxification genes may modulate the levels of oxidative stress biomarkers. METHODS: A total of 301 healthy preschool-aged children in the Seoul and Kyung-gi areas were recruited. DNA was extracted from blood for genotyping of manganese superoxide dismutase (Mn-SOD) Val16Ala, glutathione S-transferase (GST) P1 Ile105Val, GSTT1 present/null, and GSTM1 present/null polymorphisms by PCR-restriction fragment length polymorphism or multiplex PCR analyses. In addition to a questionnaire survey, the levels of urinary 8- hydroxyl-2-deoxiguanosine (8-OHdG) and plasma malondialdehyde (MDA) were measured by ELISA. RESULTS: Significantly higher urinary 8-OHdG concentrations were observed in GSTP1 Ile/Val + Val/Val genotype (p = 0.030), and tended to be higher in Mn-SOD Val/Val genotype (p = 0.065). On the other hand, exposure to environmental tobacco smoking (ETS) and interaction between ETS and gene polymorphisms did not significantly influence either urinary 8-OHdG concentrations or serum MDA. CONCLUSION: Based on our findings, GSTP1 Ile/Val gene polymorphisms might modulate the levels of oxidative stress biomarkers in healthy preschool children.