title: Polychlorinated Biphenyls and Leukocyte Telomere Length: An Analysis of NHANES 1999-2002.
abstract: Polychlorinated biphenyls (PCBs) induce the expression of the proto-oncogene c-myc which has a role in cellular growth and proliferation programs. The c-myc up-regulates the telomerase reverse transcriptase which adds the telomeres repeating sequences to the chromosomal ends to compensate for the progressive loss of telomeric sequence. We performed multivariate linear regression to analyze the association of PCBs, polychlorinated dibenzo-p-dioxins, and 1,2,3,4,6,7,8-heptachlorodibenzofuran with leukocyte telomere length (LTL) in the adult population (n = 2413) of the National Health and Nutrition Examination Survey 1999-2002. LTL was natural log-transformed and the results were re-transformed and presented as percent differences. Individuals in the 3rd and 4th quartiles of the sum of PCBs were associated with 8.33% (95% CI: 4.08-13.88) and 11.63% (95% CI: 6.18-17.35) longer LTLs, respectively, compared with the lowest quartile, with evidence of a dose-response relationship (p-trend < 0.01). The association of the sum PCBs with longer LTL was found in both sexes. Additionally, 1,2,3,4,6,7,8-heptachlorodibenzofuran and 1,2,3,6,7,8-hexachlorodibenzo-p-dioxin were associated with longer LTL. The age independent association between longer LTL and environmental exposures to PCBs, 1,2,3,4,6,7,8-heptachlorodibenzofuran and 1,2,3,6,7,8-hexachlorodibenzo-p-dioxin may support a role as tumor promoter of these compounds. Further studies to evaluate the effect of these compounds on LTL are needed to more fully understand the implications of our finding.
authors: Division of Toxicology and Human Health Sciences, Agency for Toxic Substances and Disease Registry (ATSDR), Atlanta, GA 30341, USA.
authors: Franco
authors: F
authors: Scinicariello
authors: Division of Toxicology and Human Health Sciences, Agency for Toxic Substances and Disease Registry (ATSDR), Atlanta, GA 30341, USA.
authors: Melanie C
authors: MC
authors: Buser
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000097:blood; D003430:Cross-Sectional Studies; D004781:Environmental Exposure / Q000009:adverse effects*; D004785:Environmental Pollutants / Q000633:toxicity*; D005260:Female; D006801:Humans; D007962:Leukocytes / Q000187:drug effects* / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D011078:Polychlorinated Biphenyls / Q000633:toxicity*; D000090063:Proto-Oncogene Mas; D062486:Public Health Surveillance; D016615:Telomere / Q000235:genetics*; D014481:United States / Q000453:epidemiology; D055815:Young Adult
chemical_list: D015415:Biomarkers; D004785:Environmental Pollutants; C000715470:MAS1 protein, human; D000090063:Proto-Oncogene Mas; D011078:Polychlorinated Biphenyls
keywords: Dioxin compounds; Leukocyte telomere length; NHANES; Polychlorinated biphenyls