Association of Low-Dose Exposure to Persistent Organic Pollutants with Global DNA Hypomethylation in Healthy Koreans

• Published in: Environmental health perspectives 2010-03, Vol.118 (3), p.370-374
• Main Authors: Kim, Keon-Yeop, Kim, Dong-Sun, Lee, Sung-Kook, Lee, In-Kyu, Kang, Jung-Ho, Chang, Yoon-Seok, Jacobs, David R., Steffes, Michael, Lee, Duk-Hee
• Format: Article
• Language: English
• Subjects: Adult; Age Factors; Aged; Alcohol drinking; Asian Continental Ancestry Group; Biological and medical sciences; Blood; Body mass index; Demography; Diabetes; DNA; DNA Methylation - drug effects; Environmental Exposure - adverse effects; Environmental Exposure - analysis; Environmental Pollutants - blood; Environmental Pollutants - toxicity; Female; Genetic aspects; Halogenated Diphenyl Ethers; Health; Health aspects; Humans; Hydrocarbons, Chlorinated; Korea - ethnology; Koreans; Male; Medical sciences; Methylation; Middle Aged; Organic Chemicals - blood; Organic Chemicals - toxicity; Persistent organic pollutants; Pesticides; Pesticides, fertilizers and other agrochemicals toxicology; Polychlorinated Biphenyls; Reference Values; Time Factors; Toxicology
• ISSN: 0091-6765; 1552-9924
• DOI: 10.1289/ehp.0901131

Background: Global DNA methylation levels have been reported to be inversely associated with blood levels of persistent organic pollutants (POPs), xenobiotics that accumulate in adipose tissue. Whether these associations extend to a population with much lower concentrations of POPs is not known. Objectives: This study was performed to examine whether low-dose exposure to POPs was associated with global DNA hypomethylation in Koreans. Methods: The amount of global DNA hypomethylation was estimated by the percent 5-methyl-cytosine (%5-mC) in Alu and LINE-1 assays in 86 apparently healthy Koreans. Among various POPs, organochlorine (OC) pesticides, polychlorinated biphenyls (PCBs), and polybrominated diphenylethers (PBDEs) were measured. Results: Most OC pesticides were inversely and significantly associated with %5-mC in the Alu assay, with correlation coefficients in the range -0.2 to -0.3 after adjusting for age, sex, body mass index, smoking, and alcohol. The strongest OC pesticide associations with %5-mC in the Alu assay were observed with oxychlordane, trans-nonachlor, and p,p'-dichlorodiphenyldichloroethylene. The correlation coefficient of age with %5-mC in the Alu assay was -0.24, similar to correlations of OC pesticides with %5-mC in the Alu assay. Most PCBs and PBDEs showed nonsignificant inverse trends with %5-mC in the Alu assay, but for some PCBs the U-shaped association was significant. On the other hand, POPs were not associated with %5-mC in the LINE-1 assay. Conclusions: We found that low-dose exposure to POPs, in particular OC pesticides, was associated with global DNA hypomethylation in apparently healthy Koreans.