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Mani MS, Puranik A, Kabekkodu SP, Joshi MB, Dsouza HS. Influence of VDR and HFE polymorphisms on blood lead levels of occupationally exposed workers. Hum Exp Toxicol 2020; 40:897-914. [PMID: 33233953 DOI: 10.1177/0960327120975451] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Lead is a ubiquitous heavy metal toxin of significant public health concern. Every individual varies in their response to lead's toxic effects due to underlying genetic variations in lead metabolizing enzymes or proteins distributed in the population. Earlier studies, including our lab, have attributed the influence of ALAD (δ-Aminolevulinate dehydratase) polymorphism on blood lead retention and ALAD activity. The present study aimed to investigate the influence of VDR (Vitamin D receptor) and HFE (Hemochromatosis) polymorphisms in modulating blood lead levels (BLLs) of occupationally exposed workers. 164 lead-exposed subjects involved in lead alloy manufacturing and battery breaking and recycling processes and 160 unexposed controls with BLLs below 10 µg/dL recruited in the study. Blood lead levels, along with a battery of biochemical assays and genotyping, were performed. Regression analysis revealed a negative influence of BLLs on ALAD activity (p < 0.0001) and a positive influence on smokeless tobacco use (p < 0.001) in lead-exposed subjects. A predicted haplotype of the three VDR polymorphisms computed from genotyping data revealed that T-A-A haplotype increased the BLLs by 0.93 units (p ≤ 0.05) and C-C-A haplotype decreased the BLLs by 7.25 units (p ≤ 0.05). Further analysis revealed that the wild-type CC genotype of HFE H63D presented a higher median BLL, indicating that variant C allele may have a role in increasing the concentration of lead. Hence, the polymorphism of genes associated with lead metabolism might aid in predicting genetic predisposition to lead and its associated effects.
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Affiliation(s)
- Monica Shirley Mani
- Department of Radiation Biology and Toxicology, Manipal School of Life Sciences, 76793Manipal Academy of Higher Education, Manipal, Karnataka, India
| | - Amitha Puranik
- Department of Data Science, Prasanna School of Public Health, 76793Manipal Academy of Higher Education, Manipal, Karnataka, India
| | - Shama Prasada Kabekkodu
- Department of Cellular and Molecular Biology, Manipal School of Life Sciences, 76793Manipal Academy of Higher Education, Manipal, Karnataka, India
| | - Manjunath B Joshi
- Department of Ageing, Manipal School of Life Sciences, 76793Manipal Academy of Higher Education, Manipal, Karnataka, India
| | - Herman Sunil Dsouza
- Department of Radiation Biology and Toxicology, Manipal School of Life Sciences, 76793Manipal Academy of Higher Education, Manipal, Karnataka, India
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Mani MS, Kabekkodu SP, Joshi MB, Dsouza HS. Ecogenetics of lead toxicity and its influence on risk assessment. Hum Exp Toxicol 2019; 38:1031-1059. [PMID: 31117811 DOI: 10.1177/0960327119851253] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/02/2024]
Abstract
Lead (Pb) toxicity is a public health problem affecting millions worldwide. Advances in 'omic' technology have paved the way to toxico-genomics which is currently revolutionizing the understanding of interindividual variations in susceptibility to Pb toxicity and its functional consequences to exposure. Our objective was to identify, comprehensively analyze, and curate all the potential genetic and epigenetic biomarkers studied to date in relation to Pb toxicity and its association with diseases. We screened a volume of research articles that focused on Pb toxicity and its association with genetic and epigenetic signatures in the perspective of occupational and environmental Pb exposure. Due to wide variations in population size, ethnicity, age-groups, and source of exposure in different studies, researchers continue to be skeptical on the topic of the influence of genetic variations in Pb toxicity. However, surface knowledge of the underlying genetic factors will aid in elucidating the mechanism of action of Pb. Moreover, in recent years, the application of epigenetics in Pb toxicity has become a promising area in toxicology to understand the influence of epigenetic mechanisms such as DNA methylation, chromatin remodeling, and small RNAs for the regulation of genes in response to Pb exposure during early life. Growing evidences of ecogenetic understanding (both genetic and epigenetic processes) in a dose-dependent manner may help uncover the mechanism of action of Pb and in the identification of susceptible groups. Such studies will further help in refining uncertainty factors and in addressing risk assessment of Pb poisoning.
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Affiliation(s)
- M S Mani
- 1 Department of Radiation Biology and Toxicology, Manipal School of Life Sciences, Manipal Academy of Higher Education, Manipal, Karnataka, India
| | - S P Kabekkodu
- 2 Department of Cellular and Molecular Biology, Manipal School of Life Sciences, Manipal Academy of Higher Education, Manipal, Karnataka, India
| | - M B Joshi
- 3 Department of Ageing, Manipal School of Life Sciences, Manipal Academy of Higher Education, Manipal, Karnataka, India
| | - H S Dsouza
- 1 Department of Radiation Biology and Toxicology, Manipal School of Life Sciences, Manipal Academy of Higher Education, Manipal, Karnataka, India
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Abstract
Millions of Americans now entering midlife and old age were exposed to high levels of lead, a neurotoxin, as children. Evidence from animal-model and human observational studies suggest that childhood lead exposure may raise the risk of adult neurodegenerative disease, particularly dementia, through a variety of possible mechanisms including epigenetic modification, delayed cardiovascular and kidney disease, direct degenerative CNS injury from lead remobilized from bone, and lowered neural and cognitive reserve. Within the next ten years, the generation of children with the highest historical lead exposures, those born in the 1960s, 1970s, and 1980s, will begin to enter the age at which dementia symptoms tend to emerge. Many will also enter the age in which lead stored in the skeleton may be remobilized at greater rates, particularly for women entering menopause and men and women experiencing osteoporosis. Should childhood lead exposure prove pro-degenerative, the next twenty years will provide the last opportunities for possible early intervention to forestall greater degenerative disease burden across the aging lead-exposed population. More evidence is needed now to characterize the nature and magnitude of the degenerative risks facing adults exposed to lead as children and to identify interventions to limit long-term harm.
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Affiliation(s)
- Aaron Reuben
- Department of Psychology and Neuroscience, Duke University, Durham, NC, USA
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Chen CJ, Lin TY, Wang CL, Ho CK, Chuang HY, Yu HS. Interactive Effects between Chronic Lead Exposure and the Homeostatic Iron Regulator Transport HFE Polymorphism on the Human Red Blood Cell Mean Corpuscular Volume (MCV). INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2019; 16:E354. [PMID: 30691187 PMCID: PMC6388122 DOI: 10.3390/ijerph16030354] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Revised: 01/01/2019] [Accepted: 01/12/2019] [Indexed: 12/16/2022]
Abstract
Research has shown that long-term exposure to lead harms the hematological system. The homeostatic iron regulator HFE (hemochromatosis) mutation, which has been shown to affect iron absorption and iron overload, is hypothesized to be related to lead intoxication in vulnerable individuals. The aim of our study was to investigate whether the HFE genotype modifies the blood lead levels that affect the distributions of serum iron and other red blood cell indices. Overall, 121 lead workers and 117 unexposed age-matched subjects were recruited for the study. The collected data included the blood lead levels, complete blood count, serum iron, total iron binding capacity, transferrin, and ferritin, which were measured during regular physical examinations. All subjects filled out questionnaires that included demographic information, medical history, and alcohol and tobacco consumption. HFE genotyping for C282Y and H63D was determined using polymerase chain reaction and restriction fragment length polymorphism (PCR/RFLP). The mean blood lead level in lead workers was 19.75 µg/dL and was 2.86 µg/dL in unexposed subjects. Of 238 subjects, 221 (92.9%) subjects were wild-type (CCHH) for HFE C282Y and H63D, and 17 (7.1%) subjects were heterozygous for a H63D mutation (CCHD). Multiple linear regression analysis showed that blood lead was significantly negatively associated with hemoglobin (Hb), mean corpuscular hemoglobin concentration (MCHC), and mean corpuscular volume (MCV), whereas the HFE variant was associated negatively with MCV and positively with ferritin. An interactive influence on MCV was identified between blood lead and HFE variants. Our research found a significant modifying effect of the HFE variant, which possibly affected MCV. The HFE H63D heterozygous (CCHD) variant seemed to provide a protective factor against lead toxicity. Future studies should focus on competing binding proteins between iron and lead influenced by gene variation.
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Affiliation(s)
- Chien-Juan Chen
- Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung 80708, Taiwan.
| | - Ting-Yi Lin
- Master Program of Public Health, Kaohsiung Medical University, Kaohsiung 80708, Taiwan.
| | - Chao-Ling Wang
- Department of Environmental and Occupational Medicine, Kaohsiung Medical University Hospital, Kaohsiung 80708, Taiwan.
| | - Chi-Kung Ho
- Department of Environmental and Occupational Medicine, Kaohsiung Medical University Hospital, Kaohsiung 80708, Taiwan.
- Department of Public Health, College of Health Sciences, Kaohsiung Medical University, Kaohsiung 80708, Taiwan.
| | - Hung-Yi Chuang
- Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung 80708, Taiwan.
- Department of Environmental and Occupational Medicine, Kaohsiung Medical University Hospital, Kaohsiung 80708, Taiwan.
- Department of Public Health, College of Health Sciences, Kaohsiung Medical University, Kaohsiung 80708, Taiwan.
| | - Hsin-Su Yu
- Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung 80708, Taiwan.
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Mitra P, Sharma S, Purohit P, Sharma P. Clinical and molecular aspects of lead toxicity: An update. Crit Rev Clin Lab Sci 2017; 54:506-528. [DOI: 10.1080/10408363.2017.1408562] [Citation(s) in RCA: 139] [Impact Index Per Article: 19.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Prasenjit Mitra
- Department of Biochemistry, All India Institute of Medical Sciences, Jodhpur, India
| | - Shailja Sharma
- Department of Biochemistry, All India Institute of Medical Sciences, Jodhpur, India
| | - Purvi Purohit
- Department of Biochemistry, All India Institute of Medical Sciences, Jodhpur, India
| | - Praveen Sharma
- Department of Biochemistry, All India Institute of Medical Sciences, Jodhpur, India
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Ding N, Wang X, Weisskopf MG, Sparrow D, Schwartz J, Hu H, Park SK. Lead-Related Genetic Loci, Cumulative Lead Exposure and Incident Coronary Heart Disease: The Normative Aging Study. PLoS One 2016; 11:e0161472. [PMID: 27584680 PMCID: PMC5008632 DOI: 10.1371/journal.pone.0161472] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2016] [Accepted: 08/06/2016] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND Cumulative exposure to lead is associated with cardiovascular outcomes. Polymorphisms in the δ-aminolevulinic acid dehydratase (ALAD), hemochromatosis (HFE), heme oxygenase-1 (HMOX1), vitamin D receptor (VDR), glutathione S-transferase (GST) supergene family (GSTP1, GSTT1, GSTM1), apolipoprotein E (APOE),angiotensin II receptor-1 (AGTR1) and angiotensinogen (AGT) genes, are believed to alter toxicokinetics and/or toxicodynamics of lead. OBJECTIVES We assessed possible effect modification by genetic polymorphisms in ALAD, HFE, HMOX1, VDR, GSTP1, GSTT1, GSTM1, APOE, AGTR1 and AGT individually and as the genetic risk score (GRS) on the association between cumulative lead exposure and incident coronary heart disease (CHD) events. METHODS We used K-shell-X-ray fluorescence to measure bone lead levels. GRS was calculated on the basis of 22 lead-related loci. We constructed Cox proportional hazard models to compute adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) for incident CHD. We applied inverse probability weighting to account for potential selection bias due to recruitment into the bone lead sub-study. RESULTS Significant effect modification was found by VDR, HMOX1, GSTP1, APOE, and AGT genetic polymorphisms when evaluated individually. Further, the bone lead-CHD associations became larger as GRS increases. After adjusting for potential confounders, a HR of CHD was 2.27 (95%CI: 1.50-3.42) with 2-fold increase in patella lead levels, among participants in the top tertile of GRS. We also detected an increasing trend in HRs across tertiles of GRS (p-trend = 0.0063). CONCLUSIONS Our findings suggest that lead-related loci as a whole may play an important role in susceptibility to lead-related CHD risk. These findings need to be validated in a separate cohort containing bone lead, lead-related genetic loci and incident CHD data.
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Affiliation(s)
- Ning Ding
- Department of Epidemiology, School of Public Health, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Xin Wang
- Department of Epidemiology, School of Public Health, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Marc G. Weisskopf
- Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, United States of America
| | - David Sparrow
- Veterans Affairs Normative Aging Study, Veterans Affairs Boston Healthcare System, Boston, Massachusetts, United States of America
- Department of Medicine, Boston University School of Medicine, Boston, Massachusetts, United States of America
| | - Joel Schwartz
- Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, United States of America
| | - Howard Hu
- Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario, Canada
- Department of Environmental Health Sciences, School of Public Health, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Sung Kyun Park
- Department of Epidemiology, School of Public Health, University of Michigan, Ann Arbor, Michigan, United States of America
- Department of Environmental Health Sciences, School of Public Health, University of Michigan, Ann Arbor, Michigan, United States of America
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Barrett JR. Different People, Different Outcomes: Assessing Genetic Susceptibility to Lead Exposures. ENVIRONMENTAL HEALTH PERSPECTIVES 2016; 124:A131. [PMID: 27479021 PMCID: PMC4937845 DOI: 10.1289/ehp.124-a131] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
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Nigg JT, Elmore AL, Natarajan N, Friderici KH, Nikolas MA. Variation in an Iron Metabolism Gene Moderates the Association Between Blood Lead Levels and Attention-Deficit/Hyperactivity Disorder in Children. Psychol Sci 2015; 27:257-69. [PMID: 26710823 DOI: 10.1177/0956797615618365] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2015] [Accepted: 10/29/2015] [Indexed: 12/12/2022] Open
Abstract
Although attention-deficit/hyperactivity disorder (ADHD) is a heritable neurodevelopmental condition, there is also considerable scientific and public interest in environmental modulators of its etiology. Exposure to neurotoxins is one potential source of perturbation of neural, and hence psychological, development. Exposure to lead in particular has been widely investigated and is correlated with neurodevelopmental outcomes, including ADHD. To investigate whether this effect is likely to be causal, we used a Mendelian randomization design with a functional gene variant. In a case-control study, we examined the association between ADHD symptoms in children and blood lead level as moderated by variants in the hemochromatosis (HFE) gene. The HFE gene regulates iron uptake and secondarily modulates lead metabolism. Statistical moderation was observed: The magnitude of the association of blood lead with symptoms of ADHD was altered by functional HFE genotype, which is consistent with a causal hypothesis.
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Affiliation(s)
- Joel T Nigg
- Department of Psychiatry, Oregon Health & Science University Department of Behavioral Neuroscience, Oregon Health & Science University
| | - Alexis L Elmore
- Department of Psychological & Brain Sciences, University of Iowa
| | - Neil Natarajan
- Department of Psychiatry, Oregon Health & Science University
| | - Karen H Friderici
- Department of Microbiology and Molecular Genetics, Michigan State University
| | - Molly A Nikolas
- Department of Microbiology and Molecular Genetics, Michigan State University
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Kayaalti Z, Kaya-Akyüzlü D, Söylemez E, Söylemezoğlu T. Maternal hemochromatosis gene H63D single-nucleotide polymorphism and lead levels of placental tissue, maternal and umbilical cord blood. ENVIRONMENTAL RESEARCH 2015; 140:456-461. [PMID: 25981872 DOI: 10.1016/j.envres.2015.05.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2015] [Revised: 04/30/2015] [Accepted: 05/05/2015] [Indexed: 06/04/2023]
Abstract
Human hemochromatosis protein (HFE), a major histocompatibility complex class I-like integral membrane protein, participates in the down regulation of intestinal iron absorption by binding to transferrin receptor (TR). HFE competes with transferrin-bound iron for the TR and thus reduces uptake of iron into cells. On the other hand, a lack of HFE increases the intestinal absorption of iron similarly to iron deficiency associated with increasing in absorption and deposition of lead. During pregnancy, placenta cannot prevent transfer lead to the fetus; even low-level lead poisoning causes neurodevelopmental toxicity in children. The aim of this study was to determine the association between the maternal HFE H63D single-nucleotide polymorphism and lead levels in placental tissue, maternal blood and umbilical cord bloods. The study population comprised 93 mother-placenta pairs. Venous blood from mother was collected to investigate lead levels and HFE polymorphism that was detected by standard PCR-RFLP technique. Cord bloods and placentas were collected for lead levels which were analyzed by dual atomic absorption spectrometer system. The HFE H63D genotype frequencies of mothers were found as 75.3% homozygote typical (HH), 23.6% heterozygote (HD) and 1.1% homozygote atypical (DD). Our study results showed that the placental tissue, umbilical cord and maternal blood lead levels of mothers with HD+DD genotypes were significantly higher than those with HH genotype (p<0.05). The present study indicated for the first time that mothers with H63D gene variants have higher lead levels of their newborn's placentas and umbilical cord bloods.
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Affiliation(s)
- Zeliha Kayaalti
- Ankara University, Institute of Forensic Sciences, Ankara, Turkey.
| | | | - Esma Söylemez
- Ankara University, Institute of Forensic Sciences, Ankara, Turkey; Middle Black Sea Passage Generation of Agricultural Research Station Director, Tokat, Turkey
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Grashow R, Sparrow D, Hu H, Weisskopf MG. Cumulative lead exposure is associated with reduced olfactory recognition performance in elderly men: The Normative Aging Study. Neurotoxicology 2015; 49:158-64. [PMID: 26121922 DOI: 10.1016/j.neuro.2015.06.006] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2015] [Revised: 06/05/2015] [Accepted: 06/23/2015] [Indexed: 10/23/2022]
Abstract
INTRODUCTION Olfactory dysfunction has been identified as an early warning sign for Alzheimer's disease, Parkinson's disease, dementia and more. A few occupational and environmental exposures have also been associated with reduced olfactory function, although the effects of long term environmental exposure to lead on olfactory dysfunction have not been explored. Here we performed olfactory recognition testing in elderly men in a community-dwelling cohort and examined the association with cumulative lead exposure, as assessed by lead in tibial and patellar bone. METHODS Olfactory recognition was measured in 165 men from the Normative Aging Study (NAS) who had previously taken part in bone lead measurements using K-X-ray fluorescence (KXRF). Olfactory recognition was measured using the University of Pennsylvania Smell Identification Test (UPSIT). Associations between olfactory recognition, global cognition and cumulative lead exposure were estimated using linear regression, with additional adjustment for age, smoking, and functional polymorphism status for hemochromatosis (HFE), transferrin (TfC2), glutathione-s-transferase Pi1 (GSTP1) and apolipoprotein E (APOE) genotypes. Sensitivity analyses explored olfactory recognition in men with high global cognitive function as measured using the Mini-Mental Status Exam (MMSE). RESULTS The average age of the NAS participants at the time of olfactory recognition testing was 80.3 (standard deviation or SD=5.7) years. Mean tibia lead was 16.3 (SD=12.0) μg/g bone, mean patella lead was 22.4 (SD=14.4)μg/g bone, and mean UPSIT score was 26.9 out of 40 (SD=7.0). Consistent with previous findings, age at olfaction testing was negatively associated with UPSIT score. Tibia (but not patella) bone lead was negatively associated with olfaction recognition (per 15 μg/g tibia lead: β=-1.57; 95% CI: -2.93, -0.22; p=0.02) in models adjusted for smoking and age. Additional adjustment for education did not significantly change results. Of all the genes explored, only the presence of one or more HFE variant alleles was significantly associated with olfaction recognition (HFE β=2.26; 95% CI: 0.09, 4.43; p=0.04). In a model containing the HFE term and a lead term, the tibia lead parameter estimate dropped by 21% (per 15 μg/g tibia lead: β=-1.25; 95% CI: -2.64, 0.14; p=0.08) while the HFE term dropped 15% (β=1.91; 95% CI: -0.28, 4.10; p=0.09). None of the other gene terms were associated with olfactory recognition in this cohort, nor were any gene-lead interaction terms significant. Additional sensitivity analysis in men with MMSE scores of 25 or higher (n=149) showed a similar but slightly attenuated association between lead and olfactory recognition (per 15 μg/g tibia lead β=-1.39; 95% CI: -3.00, 0.22; p=0.09). CONCLUSION Cumulative exposure to lead is associated with reduced olfactory recognition in a cohort of elderly men. The association was similar but not significant in men with better cognitive function as measured by the MMSE. Iron metabolism gene status may also affect olfactory function.
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Affiliation(s)
- Rachel Grashow
- Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, MA, USA; Department of Civil and Environmental Engineering, Northeastern University, Boston, MA, USA.
| | - David Sparrow
- VA Boston Healthcare System, Boston University Schools of Public Health and Medicine, Boston, MA, USA; Department of Medicine, Boston University School of Medicine, Boston, MA, USA
| | - Howard Hu
- Dalla Lana School of Public Health, University of Toronto, Toronto, ON, Canada
| | - Marc G Weisskopf
- Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, MA, USA
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The relationship between selected VDR, HFE and ALAD gene polymorphisms and several basic toxicological parameters among persons occupationally exposed to lead. Toxicology 2015; 334:12-21. [PMID: 25963508 DOI: 10.1016/j.tox.2015.05.002] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2015] [Revised: 05/04/2015] [Accepted: 05/06/2015] [Indexed: 02/06/2023]
Abstract
UNLABELLED The aim of this study was to find a relationship between polymorphisms of ALAD rs1805313, rs222808, rs1139488, VDR FokI and HFE C282Y and H63D and basic toxicological parameters (lead and ZnPP blood concentration) in people occupationally exposed to lead. We collected data of 101 workers (age 25-63 years) directly exposed to lead. The toxicological lab tests included blood lead, cadmium and ZnPP concentration measurement and arsenic urine concentration measurement. Workers were genotyped for ALAD (rs1805313, rs222808, rs1139488), HFE (C282Y, H63D) and VDR (FokI). Individuals with the lead exposure and coexisting F allel in the locus Fok-I of VDR gene are suspected of higher zinc protoporphyrins concentrations. Workers exposed to the lead with the Y allel in the locus C282Y of the HFE gene are predisposed to lower ZnPP levels and individuals with coexisting H allel in the locus H63D HFE gene are predisposed to lower Pb-B levels. The T allel in the locus rs1805313 of the ALAD gene determines lower Pb-B and ZnPP levels in lead-exposed individuals. The heterozigosity of the locus rs2228083 of the ALAD gene has a strong predilection to higher Pb-B levels. The carriage of the C allel in the locus rs1139488 of the ALAD gene might determine higher Pb-B levels and the heterozigosity of the locus rs1139488 of the ALAD gene might result in higher ZnPP levels. CONCLUSION The study revealed relationship between VDR, HFE and ALAD genes polymorphism and basic toxicological parameters in occupationally exposed workers.
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Barcelos GRM, Souza MFD, Oliveira AÁSD, Lengert AVH, Oliveira MTD, Camargo RBDOG, Grotto D, Valentini J, Garcia SC, Braga GÚL, Cólus IMDS, Adeyemi J, Barbosa F. Effects of genetic polymorphisms on antioxidant status and concentrations of the metals in the blood of riverside Amazonian communities co-exposed to Hg and Pb. ENVIRONMENTAL RESEARCH 2015; 138:224-232. [PMID: 25728017 DOI: 10.1016/j.envres.2015.02.017] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2014] [Revised: 02/10/2015] [Accepted: 02/14/2015] [Indexed: 06/04/2023]
Abstract
There have been reports of genetic effects affecting the metabolism of Hg and Pb individually, and thus modulating their toxicities. However, there is still a knowledge gap with respect to how genetics may influence the toxicities of these toxic metals during a co-exposure scenario. This present study is therefore aimed at investigating the effects of polymorphisms in genes (GSTM1, GSTT1, GSTP1, GCLM, GCLC, GPx1, ALAD, VDR and MDR1) that have been implicated in Hg and Pb metabolisms affects the kinetics of these metals, as well as various blood antioxidant status parameters: MDA and GSH, and the activities of CAT, GPx and ALAD among populations that have been co-exposed to both Hg and Pb. Study subjects (207 men; 188 women) were from an Amazonian population in Brazil, exposed to Hg and Pb from diet. The blood levels of Hg and Pb were determined by ICP-MS while genotyping were performed by PCR assays. The median values of Hg and Pb in blood were 39.8µg/L and 11.0µg/dL, respectively. GSTM1, ALAD and VDR polymorphisms influenced Hg in blood (β=0.17; 0.37 and 0.17; respectively, p<0.050) while variations on GCLM, GSTT1 and MDR1 (TT) modulated the concentrations of Pb among the subjects (β=-0.14; 0.13 and -0.22; re-spectively, p<0.050). GSTT1 and GCLM polymorphisms also are associated to changes of MDA concentrations. Persons with null GSTM1 genotype had higher activity of the antioxidant enzyme CAT than carries of the allele. Individuals with deletion of both GSTM1 and GSTT1 had a decreased expression of GPx compared to those that expressed at least, one of the enzymes. ALAD 1/2 subjects had lower ALAD activity than individuals with the non-variant genotype. Our findings give further support that polymorphisms related to Hg and Pb metabolism may modulate Hg and Pb body burden and, consequently metals-induced toxicity.
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Affiliation(s)
- Gustavo Rafael Mazzaron Barcelos
- Department of Clinical Analyses, Toxicology and Food Sciences, School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Avenida do Café s/no, CEP 14040-903 Ribeirão Preto, SP, Brazil.
| | - Marilesia Ferreira de Souza
- Department of General Biology, Center for Biological Sciences, State University of Londrina, Rodovia Celso Garcia Cid km 380, CEP 86051-990 Londrina, PR, Brazil
| | - Andréia Ávila Soares de Oliveira
- Department of Clinical Analyses, Toxicology and Food Sciences, School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Avenida do Café s/no, CEP 14040-903 Ribeirão Preto, SP, Brazil
| | - André van Helvoort Lengert
- Department of General Biology, Center for Biological Sciences, State University of Londrina, Rodovia Celso Garcia Cid km 380, CEP 86051-990 Londrina, PR, Brazil
| | - Marcelo Tempesta de Oliveira
- Department of General Biology, Center for Biological Sciences, State University of Londrina, Rodovia Celso Garcia Cid km 380, CEP 86051-990 Londrina, PR, Brazil
| | | | - Denise Grotto
- Department of Clinical Analyses, Toxicology and Food Sciences, School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Avenida do Café s/no, CEP 14040-903 Ribeirão Preto, SP, Brazil
| | - Juliana Valentini
- Department of Clinical Analyses, Toxicology and Food Sciences, School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Avenida do Café s/no, CEP 14040-903 Ribeirão Preto, SP, Brazil
| | - Solange Cristina Garcia
- School of Pharmacy, Federal University of Rio Grande do Sul, Avenida Ipiranga, 2752, CEP 90610-000, Porto Alegre, RS, Brazil
| | - Gilberto Úbida Leite Braga
- Department of Clinical Analyses, Toxicology and Food Sciences, School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Avenida do Café s/no, CEP 14040-903 Ribeirão Preto, SP, Brazil
| | - Ilce Mara de Syllos Cólus
- Department of General Biology, Center for Biological Sciences, State University of Londrina, Rodovia Celso Garcia Cid km 380, CEP 86051-990 Londrina, PR, Brazil
| | - Joseph Adeyemi
- Department of Biological Sciences, Faculty of Basic and Applied Sciences, Osun State University, P.M.B. 4494 Osogbo, Osun State, Nigeria
| | - Fernando Barbosa
- Department of Clinical Analyses, Toxicology and Food Sciences, School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Avenida do Café s/no, CEP 14040-903 Ribeirão Preto, SP, Brazil
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Warrington NM, Zhu G, Dy V, Heath AC, Madden PAF, Hemani G, Kemp JP, Mcmahon G, St Pourcain B, Timpson NJ, Taylor CM, Golding J, Lawlor DA, Steer C, Montgomery GW, Martin NG, Davey Smith G, Evans DM, Whitfield JB. Genome-wide association study of blood lead shows multiple associations near ALAD. Hum Mol Genet 2015; 24:3871-9. [PMID: 25820613 DOI: 10.1093/hmg/ddv112] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2014] [Accepted: 03/24/2015] [Indexed: 01/30/2023] Open
Abstract
Exposure to high levels of environmental lead, or biomarker evidence of high body lead content, is associated with anaemia, developmental and neurological deficits in children, and increased mortality in adults. Adverse effects of lead still occur despite substantial reduction in environmental exposure. There is genetic variation between individuals in blood lead concentration but the polymorphisms contributing to this have not been defined. We measured blood or erythrocyte lead content, and carried out genome-wide association analysis, on population-based cohorts of adult volunteers from Australia and UK (N = 5433). Samples from Australia were collected in two studies, in 1993-1996 and 2002-2005 and from UK in 1991-1992. One locus, at ALAD on chromosome 9, showed consistent association with blood lead across countries and evidence for multiple independent allelic effects. The most significant single nucleotide polymorphism (SNP), rs1805313 (P = 3.91 × 10(-14) for lead concentration in a meta-analysis of all data), is known to have effects on ALAD expression in blood cells but other SNPs affecting ALAD expression did not affect blood lead. Variants at 12 other loci, including ABO, showed suggestive associations (5 × 10(-6) > P > 5 × 10(-8)). Identification of genetic polymorphisms affecting blood lead reinforces the view that genetic factors, as well as environmental ones, are important in determining blood lead levels. The ways in which ALAD variation affects lead uptake or distribution are still to be determined.
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Affiliation(s)
- Nicole M Warrington
- University of Queensland Diamantina Institute, Translational Research Institute, Brisbane, Australia
| | - Gu Zhu
- QIMR Berghofer Medical Research Institute, Locked Bag 2000, Royal Brisbane Hospital, Queensland 4029, Australia
| | - Veronica Dy
- Royal Prince Alfred Hospital, Sydney, Australia
| | - Andrew C Heath
- Department of Psychiatry, Washington University School of Medicine, St Louis, MO, USA
| | - Pamela A F Madden
- Department of Psychiatry, Washington University School of Medicine, St Louis, MO, USA
| | - Gibran Hemani
- MRC Integrative Epidemiology Unit, School of Social and Community Medicine and
| | - John P Kemp
- University of Queensland Diamantina Institute, Translational Research Institute, Brisbane, Australia, MRC Integrative Epidemiology Unit, School of Social and Community Medicine and
| | - George Mcmahon
- MRC Integrative Epidemiology Unit, School of Social and Community Medicine and
| | | | - Nicholas J Timpson
- MRC Integrative Epidemiology Unit, School of Social and Community Medicine and
| | - Caroline M Taylor
- Centre for Child and Adolescent Health, School of Social and Community Medicine, University of Bristol, Bristol, UK
| | | | - Debbie A Lawlor
- MRC Integrative Epidemiology Unit, School of Social and Community Medicine and
| | - Colin Steer
- Centre for Child and Adolescent Health, School of Social and Community Medicine, University of Bristol, Bristol, UK
| | - Grant W Montgomery
- QIMR Berghofer Medical Research Institute, Locked Bag 2000, Royal Brisbane Hospital, Queensland 4029, Australia
| | - Nicholas G Martin
- QIMR Berghofer Medical Research Institute, Locked Bag 2000, Royal Brisbane Hospital, Queensland 4029, Australia
| | - George Davey Smith
- MRC Integrative Epidemiology Unit, School of Social and Community Medicine and
| | - David M Evans
- University of Queensland Diamantina Institute, Translational Research Institute, Brisbane, Australia, MRC Integrative Epidemiology Unit, School of Social and Community Medicine and
| | - John B Whitfield
- QIMR Berghofer Medical Research Institute, Locked Bag 2000, Royal Brisbane Hospital, Queensland 4029, Australia,
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14
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Jhun MA, Hu H, Schwartz J, Weisskopf MG, Nie LH, Sparrow D, Vokonas PS, Park SK. Effect modification by vitamin D receptor genetic polymorphisms in the association between cumulative lead exposure and pulse pressure: a longitudinal study. Environ Health 2015; 14:5. [PMID: 25582168 PMCID: PMC4417283 DOI: 10.1186/1476-069x-14-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2014] [Accepted: 12/27/2014] [Indexed: 05/07/2023]
Abstract
BACKGROUND Although the association between lead and cardiovascular disease is well established, potential mechanisms are still poorly understood. Calcium metabolism plays a role in lead toxicity and thus, vitamin D receptor (VDR) polymorphisms have been suggested to modulate the association between lead and health outcomes. We investigated effect modification by VDR genetic polymorphisms in the association between cumulative lead exposure and pulse pressure, a marker of arterial stiffness. METHODS We examined 727 participants (3,100 observations from follow-ups from 1991 to 2011) from the Normative Aging Study (NAS), a longitudinal study of aging. Tibia and patella bone lead levels were measured using K-x-ray fluorescence. Four single nucleotide polymorphisms (SNPs) in the VDR gene, Bsm1, Taq1, Apa1, and Fok1, were genotyped. Linear mixed effects models with random intercepts were implemented to take into account repeated measurements. RESULTS Adjusting for potential confounders, pulse pressure was 2.5 mmHg (95% CI: 0.4-4.7) and 1.9 mmHg (95% CI: 0.1-3.8) greater per interquartile range (IQR) increase in tibia lead (15 μg/g) and patella lead (20 μg/g), respectively, in those with at least one minor frequency allele in Bsm1 compared with those with major frequency allele homozygotes. The observed interaction effect between bone lead and the Bsm1 genotype persists over time during the follow-up. Similar results were observed in effect modification by Taq1. CONCLUSIONS This study suggests that subjects with the minor frequency alleles of VDR Bsm1 or Taq1 may be more susceptible to cumulative lead exposure-related elevated pulse pressure.
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Affiliation(s)
- Min A Jhun
- />Department of Epidemiology, University of Michigan School of Public Health, Ann Arbor, MI USA
| | - Howard Hu
- />Dalla Lana School of Public Health, University of Toronto, Toronto, ON Canada
| | - Joel Schwartz
- />Department of Environmental Health, Harvard School of Public Health, Boston, MA USA
| | - Marc G Weisskopf
- />Department of Environmental Health, Harvard School of Public Health, Boston, MA USA
| | - Linda H Nie
- />School of Health Sciences, Purdue University, West Lafayette, IN USA
| | - David Sparrow
- />Veterans Affairs Boston Healthcare System and Boston University School of Medicine & Public Health, Boston, MA USA
| | - Pantel S Vokonas
- />Veterans Affairs Boston Healthcare System and Boston University School of Medicine & Public Health, Boston, MA USA
| | - Sung Kyun Park
- />Department of Epidemiology, University of Michigan School of Public Health, Ann Arbor, MI USA
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15
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Mener DJ, Garcia-Esquinas E, Navas-Acien A, Dietert RR, Shargorodsky J, Lin SY. Lead exposure and increased food allergic sensitization in U.S. children and adults. Int Forum Allergy Rhinol 2014; 5:214-20. [PMID: 25524712 DOI: 10.1002/alr.21460] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2014] [Revised: 10/22/2014] [Accepted: 10/28/2014] [Indexed: 11/10/2022]
Abstract
BACKGROUND Whether blood lead levels are associated with sensitization to food allergens in adults and children is unclear. Prior studies have shown that exposure to lead is associated with atopic sensitization and modulation of several cytokines (eg, interleukin [IL]-12, IL-10, interferon [IFN]-γ, and IL-4 production) and with T-cell dysregulation and bias toward T helper 2 (Th2) activity. The objective of this work was to assess whether exposure to lead is independently associated with allergic symptoms and sensitizations in a large nationally representative sample of children and adults. METHODS We studied 2712 children and 4333 adults enrolled in the 2005-2006 cycle of the National Health and Nutritional Examination Surveys (NHANES). Participants were tested for serum-specific immunoglobulin E (IgE) levels to food allergens as well as blood lead levels. Food allergens tested included shrimp, egg, peanut, and milk. Logistic regression models adjusted for demographic factors, body mass index, history of asthma, smoking, housing characteristics, and current exposure to animals in the home, to assess the association of blood lead levels with sensitization to food allergens. RESULTS Median (interquartile range [IQR]) for serum blood was 0.87 μg/L (0.61 to 1.31) in children and 1.48 μg/L (0.92 to 2.34) in adults. At baseline, 672 (24.7%) of children participants and 719 (16.6%) of adult participants tested positive for increased sensitization to food allergens. A 2-fold increase in blood lead levels in adult participants was associated with increased sensitization to food allergens (odds ratio [OR], 1.11; 95% confidence interval [CI], 1.02 to 1.22). Blood lead was not associated with sensitization to food allergens among pediatric participants (OR, 0.95; 95% CI, 0.82 to 1.10). CONCLUSION Exposure to lead was associated with increased odds of sensitization to food allergens in adult but not children participants.
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Affiliation(s)
- David J Mener
- Department of Otolaryngology-Head and Neck Surgery, Johns Hopkins School of Medicine, Baltimore, MD
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16
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Karwowski MP, Just AC, Bellinger DC, Jim R, Hatley EL, Ettinger AS, Hu H, Wright RO. Maternal iron metabolism gene variants modify umbilical cord blood lead levels by gene-environment interaction: a birth cohort study. Environ Health 2014; 13:77. [PMID: 25287020 PMCID: PMC4271345 DOI: 10.1186/1476-069x-13-77] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2014] [Accepted: 09/26/2014] [Indexed: 05/06/2023]
Abstract
BACKGROUND Given the relationship between iron metabolism and lead toxicokinetics, we hypothesized that polymorphisms in iron metabolism genes might modify maternal-fetal lead transfer. The objective of this study was to determine whether maternal and/or infant transferrin (TF) and hemochromatosis (HFE) gene missense variants modify the association between maternal blood lead (MBL) and umbilical cord blood lead (UCBL). METHODS We studied 476 mother-infant pairs whose archived blood specimens were genotyped for TF P570S, HFE H63D and HFE C282Y. MBL and UCBL were collected within 12 hours of delivery. Linear regression models were used to examine the association between log-transformed MBL and UCBL, examine for confounding and collinearity, and explore gene-environment interactions. RESULTS The geometric mean MBL was 0.61 μg/dL (range 0.03, 3.2) and UCBL 0.42 (<0.02, 3.9). Gene variants were common with carrier frequencies ranging from 12-31%; all were in Hardy-Weinberg equilibrium. In an adjusted linear regression model, log MBL was associated with log UCBL (β = 0.92, 95% CI: 0.82, 1.03; p < 0.01) such that a 1% increase in MBL was associated with a 0.92% increase in UCBL among infants born to wild-type mothers. In infants born to C282Y variants, however, a 1% increase in MBL is predicted to increase UCBL 0.65% (β(Main Effect) = -0.002, 95% CI: -0.09, -0.09; p = 0.97; β(Interaction) = -0.27, 95% CI: -0.52, -0.01; p = 0.04), representing a 35% lower placental lead transfer among women with MBL 5 μg/dL. CONCLUSIONS Maternal HFE C282Y gene variant status is associated with greater reductions in placental transfer of lead as MBL increases. The inclusion of gene-environment interaction in risk assessment models may improve efforts to safeguard vulnerable populations.
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Affiliation(s)
- Mateusz P Karwowski
- />Division of General Pediatrics, Pediatric Environmental Health Center, Boston Children’s Hospital, Boston, MA USA
- />Department of Environmental Health, Harvard School of Public Health, Boston, MA USA
| | - Allan C Just
- />Department of Environmental Health, Harvard School of Public Health, Boston, MA USA
| | - David C Bellinger
- />Department of Environmental Health, Harvard School of Public Health, Boston, MA USA
- />Department of Neurology, Boston Children’s Hospital, Boston, MA USA
| | - Rebecca Jim
- />Local Environmental Action Demanded Agency, Inc, Miami, OK USA
| | - Earl L Hatley
- />Local Environmental Action Demanded Agency, Inc, Miami, OK USA
| | - Adrienne S Ettinger
- />Department of Chronic Disease Epidemiology, Center for Perinatal, Pediatric, and Environmental Epidemiology, Yale School of Public Health, New Haven, CT USA
| | - Howard Hu
- />Divisions of Clinical Public Health, Epidemiology, Global Health, and Occupational and Environmental Health, Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario Canada
| | - Robert O Wright
- />Departments of Preventive Medicine and Pediatrics, Icahn School of Medicine at Mt. Sinai, New York, NY USA
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17
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Schneider JS, Talsania K, Mettil W, Anderson DW. Genetic diversity influences the response of the brain to developmental lead exposure. Toxicol Sci 2014; 141:29-43. [PMID: 24913800 PMCID: PMC4271117 DOI: 10.1093/toxsci/kfu101] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2014] [Accepted: 05/14/2014] [Indexed: 11/14/2022] Open
Abstract
Although extrinsic factors, such as nutritional status, and some intrinsic genetic factors may modify susceptibility to developmental lead (Pb) poisoning, no studies have specifically examined the influence of genetic background on outcomes from Pb exposure. In this study, we used gene microarray profiling to identify Pb-responsive genes in rats of different genetic backgrounds, including inbred (Fischer 344 (F344)) and outbred (Long Evans (LE), Sprague Dawley (SD)) strains, to investigate the role that genetic variation may play in influencing outcomes from developmental Pb exposure. Male and female animals received either perinatal (gestation through lactation) or postnatal (birth through weaning) exposure to Pb in food (0, 250, or 750 ppm). RNA was extracted from the hippocampus at day 55 and hybridized to Affymetrix Rat Gene 1.0 ST Arrays. There were significant strain-specific effects of Pb on the hippocampal transcriptome with 978 transcripts differentially expressed in LE rats across all experimental groups, 269 transcripts differentially expressed in F344 rats, and only 179 transcripts differentially expressed in SD rats. These results were not due to strain-related differences in brain accumulation of Pb. Further, no genes were consistently differentially regulated in all experimental conditions. There was no set of "Pb toxicity" genes that are a molecular signature for Pb neurotoxicity that transcended sex, exposure condition, and strain. These results demonstrate the influence that strain and genetic background play in modifying the brain's response to developmental Pb exposure and may have relevance for better understanding the molecular underpinnings of the lack of a neurobehavioral signature in childhood Pb poisoning.
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Affiliation(s)
- Jay S Schneider
- Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, Philadelphia, Pennsylvania 19107
| | - Keyur Talsania
- Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, Philadelphia, Pennsylvania 19107
| | - William Mettil
- Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, Philadelphia, Pennsylvania 19107
| | - David W Anderson
- Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, Philadelphia, Pennsylvania 19107
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18
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The effect of the hemochromatosis (HFE) genotype on lead load and iron metabolism among lead smelter workers. PLoS One 2014; 9:e101537. [PMID: 24988074 PMCID: PMC4079697 DOI: 10.1371/journal.pone.0101537] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2014] [Accepted: 06/06/2014] [Indexed: 12/28/2022] Open
Abstract
Background Both an excess of toxic lead (Pb) and an essential iron disorder have been implicated in many diseases and public health problems. Iron metabolism genes, such as the hemochromatosis (HFE) gene, have been reported to be modifiers for lead absorption and storage. However, the HFE gene studies among the Asian population with occupationally high lead exposure are lacking. Objectives To explore the modifying effects of the HFE genotype (wild-type, H63D variant and C282Y variant) on the Pb load and iron metabolism among Asian Pb-workers with high occupational exposure. Methods Seven hundred and seventy-one employees from a lead smelter manufacturing company were tested to determine their Pb intoxication parameters, iron metabolic indexes and identify the HFE genotype. Descriptive and multivariate analyses were conducted. Results Forty-five H63D variant carriers and no C282Y variant carrier were found among the 771 subjects. Compared with subjects with the wild-type genotype, H63D variant carriers had higher blood lead levels, even after controlling for factors such as age, sex, marriage, education, smoking and lead exposure levels. Multivariate analyses also showed that the H63D genotype modifies the associations between the blood lead levels and the body iron burden/transferrin. Conclusions No C282Y variant was found in this Asian population. The H63D genotype modified the association between the lead and iron metabolism such that increased blood lead is associated with a higher body iron content or a lower transferrin in the H63D variant. It is indicated that H63D variant carriers may be a potentially highly vulnerable sub-population if they are exposed to high lead levels occupationally.
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19
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Kim J, Lee Y, Yang M. Environmental exposure to lead (Pb) and variations in its susceptibility. JOURNAL OF ENVIRONMENTAL SCIENCE AND HEALTH. PART C, ENVIRONMENTAL CARCINOGENESIS & ECOTOXICOLOGY REVIEWS 2014; 32:159-85. [PMID: 24875442 DOI: 10.1080/10590501.2014.907461] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Based on exposure frequency and intrinsic toxicity, lead (Pb) ranks one of the highest priority toxic materials. Continuous regulation of environmental Pb exposure has contributed to dramatically diminished exposure levels of Pb, for example, blood level of Pb. However, the safety level of Pb is not established, as low-level exposure to Pb still shows severe toxicity in high susceptible population and late onset of some diseases from early exposure. In the present study, we focused on food-borne Pb exposure and found broad variations in Pb exposure levels via food among countries. In addition, there are genetic or ethnical variations in Pb-targeted and protective genes. Moreover, various epigenetic alterations were induced by Pb poisoning. Therefore, we suggest a systemic approach including governmental (public) and individual prevention from Pb exposure with continuous biological monitoring and genetic or epigenetic consideration.
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Affiliation(s)
- Jina Kim
- a Research Center for Cell Fate Control, College of Pharmacy , Sookmyung Women's University , Seoul , Republic of Korea
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20
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Silver MK, Lozoff B, Meeker JD. Blood cadmium is elevated in iron deficient U.S. children: a cross-sectional study. Environ Health 2013; 12:117. [PMID: 24373608 PMCID: PMC3883480 DOI: 10.1186/1476-069x-12-117] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2013] [Accepted: 12/18/2013] [Indexed: 05/04/2023]
Abstract
BACKGROUND Cadmium (Cd), a widespread environmental contaminant, and iron deficiency (ID), the most common nutrient deficiency in the world, are known risk factors for neurodevelopmental delays, as well as other disorders, in infants and children. Studies assessing the cumulative effects of these factors are lacking in children, despite concerns of increased uptake of metals in the presence of ID. Here we sought to determine if blood and urine Cd levels were elevated in ID children compared to non-ID children. METHODS Data for 5224 children, aged 3-19 years, were obtained from the 1999-2002 NHANES. ID was defined as ≥2 of 3 abnormal iron indicators (low serum ferritin [SF], high free erythrocyte protoporphyrin [FEP], low % transferrin saturation [TSAT]); ID anemia (IDA) was defined as ID plus low hemoglobin (Hgb). Logistic regression was used to evaluate associations between ID, IDA, and abnormal iron indicators and categories of blood and urine Cd. RESULTS Adjusted odds of ID, IDA, low SF, and low TSAT were associated with increasing category of blood Cd but not urine Cd. Adjusted ORs (95% CI) for blood Cd ≥0.5 μg/L versus < LOD were = 1.74 (1.30-2.34), 4.02 (1.92-8.41), 4.08 (2.36-5.89) and 1.78 (1.32-2.39), for ID, IDA, low SF, and low TSAT, respectively. Age and sex specific analyses of blood Cd and ID/abnormal iron indicators revealed that the observed associations were strongest in females aged 16-19 years. CONCLUSIONS Given their shared neurotoxic effects in children, and that many people live in areas with high burdens of both ID and Cd, more research into the complex relationships between nutrient deficiencies and environmental toxicants is vital.
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Affiliation(s)
- Monica K Silver
- Department of Environmental Health Sciences, University of Michigan School of Public Health, Ann Arbor, Michigan, USA
| | - Betsy Lozoff
- Center for Human Growth and Development, University of Michigan, Ann Arbor, Michigan, USA
| | - John D Meeker
- Department of Environmental Health Sciences, University of Michigan School of Public Health, Ann Arbor, Michigan, USA
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21
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Diacomanolis V, Noller BN, Ng JC. Interaction effects of lead on bioavailability and pharmacokinetics of arsenic in the rat. ENVIRONMENTAL GEOCHEMISTRY AND HEALTH 2013; 35:757-766. [PMID: 23728997 DOI: 10.1007/s10653-013-9527-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/03/2013] [Accepted: 03/26/2013] [Indexed: 06/02/2023]
Abstract
Arsenic (As) and lead (Pb) are common contaminants found in mine waste materials. For an evidence-based risk assessment, it is important to better understand the potential interaction of mixed contaminants; and this interaction study was investigated in an in vivo rat model. Following co-administration of a fixed dose of As(V) as in sodium arsenate and different doses of Pb as lead acetate to Sprague-Dawley rats, blood arsenic concentration and bioavailability decreased. A decrease in As blood concentration when lead was co-administered was observed with increasing lead doses. Pharmacokinetic parameters for As in the blood showed faster absorption and elimination of this metalloid in the presence of Pb. The elimination half-life of As decreased from 67 days in As solo group to 27-30 with doses of Pb. Bioavailability of As was also decreased by 30-43 % in the presence of Pb. Decreased urinary excretion of Pb and tissue accumulation were also observed. It indicates lower absorption of As when co-administered with Pb. A probable explanation for these findings is that As co-administration with Pb could have resulted in the formation of less soluble lead arsenate. However, such an interaction between As and Pb could only explain about one-third of the variation when real mine waste materials containing both of these elements were administered to rats. This suggests that other effects from physical and chemical parameters could contribute to the bioavailability of arsenic in complex real environmental samples.
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Affiliation(s)
- Violet Diacomanolis
- National Research Centre for Environmental Toxicity, The University of Queensland, 39 Kessels Rd, Coopers Plains, Brisbane, QLD, 4108, Australia,
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22
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Power MC, Weisskopf MG, Alexeeff SE, Wright RO, Coull BA, Spiro A, Schwartz J. Modification by hemochromatosis gene polymorphisms of the association between traffic-related air pollution and cognition in older men: a cohort study. Environ Health 2013; 12:16. [PMID: 23413885 PMCID: PMC3599892 DOI: 10.1186/1476-069x-12-16] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2012] [Accepted: 01/11/2013] [Indexed: 05/28/2023]
Abstract
BACKGROUND Previous studies found effect modification of associations between traffic-related air pollution and cardiovascular outcomes by polymorphisms in the hemochromatosis gene (HFE). As traffic-related air pollution may impact cognition through effects on cardiovascular health or through mechanisms which may also influence cardiovascular outcomes, we hypothesized that HFE polymorphisms would also modify a previously observed association between traffic-related air pollution exposure and cognition in older men. METHODS We considered data from 628 participants of the VA Normative Aging Study. We estimated long term exposure to black carbon (BC), a marker of traffic related air pollution, using a spatio-temporal land use regression model. We assessed cognition using the Mini-Mental State Examination (MMSE), a test of global function, and performance on a battery of other tests, covering a wide range of domains. We investigated whether variants of HFE C282Y and H63D modified the association between BC and having a low MMSE score using logistic models with generalized estimating equations and multiplicative interaction terms. Similarly, we assessed whether HFE variants modified the association between BC and performance on the cognitive battery using linear mixed models with multiplicative interaction terms. RESULTS Our results suggest modification of the BC-cognition association by HFE C282Y, although the test of interaction did not achieve statistical significance. In multivariable-adjusted models, participants who lacked a HFE C282Y variant (CC) exhibited an adverse association between BC and total cognition z-score (beta for a doubling in BC concentration: -0.061, 95% CI: -0.115, -0.007), while we did not observe an association in participants with at least one variant genotype (CY or YY) (beta for a doubling in BC concentration: 0.073, 95% CI: -0.081, 0.228; p-value for interaction: 0.11). The pattern of association was similar for analyses considering performance on the Mini-Mental State Examination. There was little evidence to support effect modification of the BC-cognition association by the HFE H63D genotype. CONCLUSIONS Our data suggest that older adults who lack an HFE C282Y variant may be more susceptible to an adverse effect of traffic-related air pollution exposure on cognition. This finding and the proposed biological mechanism require confirmation.
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Affiliation(s)
- Melinda C Power
- Department of Epidemiology, Harvard School of Public Health, 677 Huntington Avenue, Boston, MA 02115, USA
- Department of Environmental Health, Harvard School of Public Health, 677 Huntington Avenue, Boston, MA 02115, USA
| | - Marc G Weisskopf
- Department of Epidemiology, Harvard School of Public Health, 677 Huntington Avenue, Boston, MA 02115, USA
- Department of Environmental Health, Harvard School of Public Health, 677 Huntington Avenue, Boston, MA 02115, USA
| | - Stacey E Alexeeff
- Department of Biostatistics, Harvard School of Public Health, 677 Huntington Avenue, Boston, MA, 02115, USA
| | - Robert O Wright
- Department of Environmental Health, Harvard School of Public Health, 677 Huntington Avenue, Boston, MA 02115, USA
| | - Brent A Coull
- Department of Biostatistics, Harvard School of Public Health, 677 Huntington Avenue, Boston, MA, 02115, USA
| | - Avron Spiro
- Veterans Affairs Boston Healthcare System, 150 S. Huntington Avenue, Boston, MA, 02130, USA
- Department of Epidemiology, Boston University School of Public Health, 715 Albany Street, Boston, MA, 02118, USA
- Department of Psychiatry, Boston University Medical School, 72 East Concord Street, Boston, MA, 02118, USA
| | - Joel Schwartz
- Department of Epidemiology, Harvard School of Public Health, 677 Huntington Avenue, Boston, MA 02115, USA
- Department of Environmental Health, Harvard School of Public Health, 677 Huntington Avenue, Boston, MA 02115, USA
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Claus Henn B, Kim J, Wessling-Resnick M, Téllez-Rojo MM, Jayawardene I, Ettinger AS, Hernández-Avila M, Schwartz J, Christiani DC, Hu H, Wright RO. Associations of iron metabolism genes with blood manganese levels: a population-based study with validation data from animal models. Environ Health 2011; 10:97. [PMID: 22074419 PMCID: PMC3248860 DOI: 10.1186/1476-069x-10-97] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2011] [Accepted: 11/10/2011] [Indexed: 05/10/2023]
Abstract
BACKGROUND Given mounting evidence for adverse effects from excess manganese exposure, it is critical to understand host factors, such as genetics, that affect manganese metabolism. METHODS Archived blood samples, collected from 332 Mexican women at delivery, were analyzed for manganese. We evaluated associations of manganese with functional variants in three candidate iron metabolism genes: HFE [hemochromatosis], TF [transferrin], and ALAD [δ-aminolevulinic acid dehydratase]. We used a knockout mouse model to parallel our significant results as a novel method of validating the observed associations between genotype and blood manganese in our epidemiologic data. RESULTS Percentage of participants carrying at least one copy of HFE C282Y, HFE H63D, TF P570S, and ALAD K59N variant alleles was 2.4%, 17.7%, 20.1%, and 6.4%, respectively. Percentage carrying at least one copy of either C282Y or H63D allele in HFE gene was 19.6%. Geometric mean (geometric standard deviation) manganese concentrations were 17.0 (1.5) μg/l. Women with any HFE variant allele had 12% lower blood manganese concentrations than women with no variant alleles (β = -0.12 [95% CI = -0.23 to -0.01]). TF and ALAD variants were not significant predictors of blood manganese. In animal models, Hfe(-/-) mice displayed a significant reduction in blood manganese compared with Hfe(+/+) mice, replicating the altered manganese metabolism found in our human research. CONCLUSIONS Our study suggests that genetic variants in iron metabolism genes may contribute to variability in manganese exposure by affecting manganese absorption, distribution, or excretion. Genetic background may be critical to consider in studies that rely on environmental manganese measurements.
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Affiliation(s)
- Birgit Claus Henn
- Department of Environmental Health, Harvard School of Public Health, Boston, MA, USA
| | - Jonghan Kim
- Department of Genetics and Complex Diseases, Harvard School of Public Health, Boston, MA, USA
| | | | - Martha María Téllez-Rojo
- Division of Statistics, Center for Evaluation Research and Surveys, National Institute of Public Health, Cuernavaca, Morelos, Mexico
| | - Innocent Jayawardene
- Channing Laboratory, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston MA, USA
| | - Adrienne S Ettinger
- Department of Environmental Health, Harvard School of Public Health, Boston, MA, USA
- Center for Perinatal, Pediatric and Environmental Epidemiology, Department of Epidemiology and Public Health, Yale University School of Medicine, New Haven, Connecticut 06510, USA
| | | | - Joel Schwartz
- Department of Environmental Health, Harvard School of Public Health, Boston, MA, USA
| | - David C Christiani
- Department of Environmental Health, Harvard School of Public Health, Boston, MA, USA
| | - Howard Hu
- Department of Environmental Health Sciences, University of Michigan School of Public Health, Ann Arbor, MI, USA
| | - Robert O Wright
- Department of Environmental Health, Harvard School of Public Health, Boston, MA, USA
- Department of Emergency Medicine, Children's Hospital Boston, Boston, MA, USA
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A transdisciplinary perspective of chronic stress in relation to psychopathology throughout life span development. Dev Psychopathol 2011; 23:725-76. [DOI: 10.1017/s0954579411000289] [Citation(s) in RCA: 170] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
AbstractThe allostatic load (AL) model represents an interdisciplinary approach to comprehensively conceptualize and quantify chronic stress in relation to pathologies throughout the life cycle. This article first reviews the AL model, followed by interactions among early adversity, genetics, environmental toxins, as well as distinctions among sex, gender, and sex hormones as integral antecedents of AL. We next explore perspectives on severe mental illness, dementia, and caregiving as unique human models of AL that merit future investigations in the field of developmental psychopathology. A complimenting transdisciplinary perspective is applied throughout, whereby we argue that the AL model goes beyond traditional stress–disease theories toward the advancement of person-centered research and practice that promote not only physical health but also mental health.
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Zhang A, Park SK, Wright RO, Weisskopf MG, Mukherjee B, Nie H, Sparrow D, Hu H. HFE H63D polymorphism as a modifier of the effect of cumulative lead exposure on pulse pressure: the Normative Aging Study. ENVIRONMENTAL HEALTH PERSPECTIVES 2010; 118:1261-6. [PMID: 20478760 PMCID: PMC2944087 DOI: 10.1289/ehp.1002251] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2010] [Accepted: 05/14/2010] [Indexed: 05/06/2023]
Abstract
BACKGROUND Cumulative lead exposure is associated with a widened pulse pressure (PP; the -difference between systolic and diastolic blood pressure), a marker of arterial stiffness and a predictor of cardiovascular disease. Polymorphisms in the hemochromatosis gene (HFE) have been shown to modify the impact of cumulative lead exposure on measures of adult cognition and cardiac function. OBJECTIVES We examined whether the HFE mutations modify the impact of lead on PP in -community-dwelling older men. METHODS We examined 619 participants with a total of 1,148 observations of PP from a substudy of bone lead levels (a measure of cumulative exposure, measured by in vivo K-shell X-ray fluorescence) and health in the Normative Aging Study between 1991 and 2001. Linear mixed-effects regression models with random intercepts were constructed. RESULTS Of the 619 subjects, 138 and 72 carried the HFE H63D and C282Y variants, respectively. After adjusting for age; education; alcohol intake; smoking; daily intakes of calcium, sodium, and potassium; total calories; family history of hypertension; diabetes; height; heart rate; high-density lipoprotein (HDL); total cholesterol:HDL ratio; and waist circumference, baseline bone lead levels were associated with steeper increases in PP in men with at least one H63D allele (p-interaction = 0.03 for tibia and 0.02 for patella) compared with men with only the wild types or C282Y variant. CONCLUSIONS The HFE H63D polymorphism, but not the C282Y mutation, appears to enhance susceptibility to the deleterious impact of cumulative lead on PP, possibly via prooxidative or pro-inflammatory mechanisms.
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Affiliation(s)
- Aimin Zhang
- Department of Environmental Health Sciences, University of Michigan School of Public Health, Ann Arbor, Michigan, USA.
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Cantonwine D, Hu H, Téllez-Rojo MM, Sánchez BN, Lamadrid-Figueroa H, Ettinger AS, Mercado-García A, Hernández-Avila M, Wright RO. HFE gene variants modify the association between maternal lead burden and infant birthweight: a prospective birth cohort study in Mexico City, Mexico. Environ Health 2010; 9:43. [PMID: 20659343 PMCID: PMC2916893 DOI: 10.1186/1476-069x-9-43] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2010] [Accepted: 07/26/2010] [Indexed: 05/11/2023]
Abstract
BACKGROUND Neonatal growth is a complex process involving genetic and environmental factors. Polymorphisms in the hemochromatosis (HFE) iron regulatory genes have been shown to modify transport and toxicity of lead which is known to affect birth weight. METHODS We investigated the role of HFE C282Y, HFE H63 D, and transferrin (TF) P570 S gene variants in modifying the association of lead and infant birthweight in a cohort of Mexican mother-infant pairs. Subjects were initially recruited between 1994-1995 from three maternity hospitals in Mexico City and 411 infants/565 mothers had archived blood available for genotyping. Multiple linear regression models, stratified by either maternal/infant HFE or TF genotype and then combined with interaction terms, were constructed examining the association of lead and birthweight after controlling for covariates. RESULTS 3.1%, 16.8% and 17.5% of infants (N=390) and 1.9%, 14.5% and 18.9% of mothers (N=533) carried the HFE C282Y, HFE H63D, and TF P570 S variants, respectively. The presence of infant HFE H63 D variants predicted 110.3 g (95% CI -216.1, -4.6) decreases in birthweight while maternal HFE H63 D variants predicted reductions of 52.0 g (95% CI -147.3 to 43.2). Interaction models suggest that both maternal and infant HFE H63 D genotype may modify tibia lead's effect on infant birthweight in opposing ways. In our interaction models, maternal HFE H63 D variant carriers had a negative association between tibia lead and birthweight. CONCLUSIONS These results suggest that the HFE H63 D genotype modifies lead's effects on infant birthweight in a complex fashion that may reflect maternal-fetal interactions with respect to the metabolism and transport of metals.
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Affiliation(s)
- David Cantonwine
- Department of Environmental Health Sciences, University of Michigan School of Public Health, Ann Arbor, Michigan, USA
| | - Howard Hu
- Department of Environmental Health Sciences, University of Michigan School of Public Health, Ann Arbor, Michigan, USA
- Department of Environmental Health, Harvard School of Public Health, Boston, Massachusetts, USA
- Channing Laboratory, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Martha Maria Téllez-Rojo
- Division of Statistics, Center for Evaluation Research and Surveys, National Institute of Public Health, Cuernavaca, Morelos, México
| | - Brisa N Sánchez
- Department of Biostatistics, University of Michigan School of Public Health, Ann Arbor, Michigan, USA
| | - Héctor Lamadrid-Figueroa
- Division of Statistics, Center for Evaluation Research and Surveys, National Institute of Public Health, Cuernavaca, Morelos, México
| | - Adrienne S Ettinger
- Department of Environmental Health, Harvard School of Public Health, Boston, Massachusetts, USA
- Channing Laboratory, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Adriana Mercado-García
- Division of Environmental Health, Center for Population Health Research, National Institute of Public Health, Cuernavaca, Morelos, México
| | | | - Robert O Wright
- Department of Environmental Health, Harvard School of Public Health, Boston, Massachusetts, USA
- Channing Laboratory, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA
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Gundacker C, Gencik M, Hengstschläger M. The relevance of the individual genetic background for the toxicokinetics of two significant neurodevelopmental toxicants: mercury and lead. Mutat Res 2010; 705:130-140. [PMID: 20601101 DOI: 10.1016/j.mrrev.2010.06.003] [Citation(s) in RCA: 98] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2010] [Revised: 06/07/2010] [Accepted: 06/10/2010] [Indexed: 11/25/2022]
Abstract
The heavy metals mercury and lead are well-known and significant developmental neurotoxicants. This review summarizes the genetic factors that modify their toxicokinetics. Understanding toxicokinetics (uptake, biotransformation, distribution, and elimination processes) is a key precondition to understanding the individual health risks associated with exposure. We selected candidate susceptibility genes when evidence was available for (1) genes/proteins playing a significant role in mercury and lead toxicokinetics, (2) gene expression/protein activity being induced by these metals, and (3) mercury and lead toxicokinetics being affected by gene knockout/knockdown or (4) by functional gene polymorphisms. The genetic background is far better known for mercury than for lead toxicokinetics. Involved are genes encoding L-type amino acid transporters, organic anion transporters, glutathione (GSH)-related enzymes, metallothioneins, and transporters of the ABC family. Certain gene variants can influence mercury toxicokinetics, potentially explaining part of the variable susceptibility to mercury toxicity. Delta-aminolevulinic acid dehydratase (ALAD), vitamin D receptor (VDR) and hemochromatosis (HFE) gene variants are the only well-established susceptibility markers of lead toxicity in humans. Many gaps remain in our knowledge about the functional genomics of this issue. This calls for studies to detect functional gene polymorphisms related to mercury- and lead-associated disease phenotypes, to demonstrate the impact of functional polymorphisms and gene knockout/knockdown in relation to toxicity, to confirm the in vivo relevance of genetic variation, and to examine gene-gene interactions on the respective toxicokinetics. Another crucial aspect is knowledge on the maternal-fetal genetic background, which modulates fetal exposure to these neurotoxicants. To completely define the genetically susceptible risk groups, research is also needed on the genes/proteins involved in the toxicodynamics, i.e., in the mechanisms causing adverse effects in the brain. Studies relating the toxicogenetics to neurodevelopmental disorders are lacking (mercury) or very scarce (lead). Thus, the extent of variability in susceptibility to heavy metal-associated neurological outcomes is poorly characterized.
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Affiliation(s)
- Claudia Gundacker
- Institute of Medical Genetics, Medical University of Vienna, Währinger Strasse 10, A-1090 Vienna, Austria.
| | - Martin Gencik
- Praxis fur Humangenetik, Brünnlbadgasse 15, A-1090 Vienna, Austria
| | - Markus Hengstschläger
- Institute of Medical Genetics, Medical University of Vienna, Währinger Strasse 10, A-1090 Vienna, Austria
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Bone lead level prediction models and their application to examine the relationship of lead exposure and hypertension in the Third National Health and Nutrition Examination Survey. J Occup Environ Med 2010; 51:1422-36. [PMID: 19952788 DOI: 10.1097/jom.0b013e3181bf6c8d] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVE We developed prediction models for bone lead using blood lead levels and other standard covariates in a community-based cohort of older men. METHODS Participants having bone lead levels measured by K X-ray fluorescence were included in the model selection process (n = 825). Predictors of each tibia and patella lead were identified in three quarters of the population and then predicted the bone lead levels in the remaining one quarter and in the Community Lead Study. RESULTS Eighteen predictors were selected for tibia (blood lead, age, education, occupation, smoking status, pack-years of cigarette, serum levels of phosphorus, uric acid, calcium, creatinine and total and high-density lipoprotein cholesterols, hematocrit, body mass index, systolic and diastolic blood pressure, and diagnoses of cancer and diabetes; R2 = 0.32) and 16 for patella lead (among the predictors included in the tibia model diagnosis of cancer, serum levels of calcium, and total cholesterol were not included in patella lead model, but diagnosis of hypertension was included; R2 = 0.34), respectively. The correlation coefficients between the observed and predicted values were 0.43 to 0.50 for tibia and 0.52 to 0.58 for patella lead in internal and external validation. We applied these predicted bone lead models to the Third National Health and Nutrition Examination Survey (NHANES-III) to examine associations with hypertension and found relatively more significant associations compared with blood lead. CONCLUSIONS This study suggests that the prediction equations may be used to predict bone lead levels in other community-based cohorts with reasonable accuracy.
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Roy A, Hu H, Bellinger DC, Palaniapan K, Wright RO, Schwartz J, Balakrishnan K. Predictors of blood lead in children in Chennai, India (2005-2006). INTERNATIONAL JOURNAL OF OCCUPATIONAL AND ENVIRONMENTAL HEALTH 2009; 15:351-9. [PMID: 19886345 DOI: 10.1179/oeh.2009.15.4.351] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Abstract
Lead has been phased out of gasoline in India since 2001. However, elevated blood lead levels continue to be reported, and little is known about the predictors of lead exposure. The purpose of this study was to examine the lead burden and identify possible predictors of blood lead among children in Chennai, India after the phase-out of leaded gasoline. Subjects were children from twelve schools in Chennai. Venous blood was collected and analyzed for lead. Demographic, environmental, and nutritional information was collected using questionnaires administered to the primary caregiver. Generalized estimating equations were used to assess predictors of blood lead. We found that lead exposure remains elevated among children four or more years after the phase-out of lead from gasoline. Industrial activity, water storage vessels, and lower socio-economic status are predictors of elevated blood lead in this population, but additional work is required to better define preventable risk factors.
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Affiliation(s)
- Ananya Roy
- University of Michigan School of Public Health 109 Observatory St., 1700 SPH i, Ann Arbor, MI 48109-2029, USA.
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Gundacker C, Wittmann KJ, Kukuckova M, Komarnicki G, Hikkel I, Gencik M. Genetic background of lead and mercury metabolism in a group of medical students in Austria. ENVIRONMENTAL RESEARCH 2009; 109:786-796. [PMID: 19515364 DOI: 10.1016/j.envres.2009.05.003] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2008] [Revised: 05/14/2009] [Accepted: 05/19/2009] [Indexed: 05/27/2023]
Abstract
BACKGROUND Information on the impact of genetic predisposition on metal toxicokinetics in the human body is limited. There is increasing evidence that certain genetic polymorphisms modify lead and mercury toxicokinetics. This called for analysis of further candidate genes. OBJECTIVES Medical students (N=324) were examined in order to detect potential associations between lead exposure and polymorphisms in HFE, VDR, ALAD, and MT genes, as well as between mercury exposure and GSTT1, GSTM1, GSTA1, GSTP1, GCLC, and MT polymorphisms. METHODS The levels of lead and mercury exposure of students were determined by blood, urine, and hair analyses (ICP-MS, CV-AAS). Genotyping of common polymorphisms was examined by MALDI-TOF MS and the TaqMan methodology. Associations between lead and mercury exposures and genetic background were examined by bivariate analysis, and by categorical regression analysis (CATREG) controlled by metal- and matrix-specific variables. RESULTS Lead and mercury levels in urine, blood, and hair indicated low exposures. VDR polymorphism and joint presence of VDR/ALAD polymorphisms were significantly and independently associated with urine lead concentrations (CATREG P<0.05). Polymorphisms in GSTP1-114 and MT4 genes as well as dual gene combinations including GSTP1, GCLC, GSTT1, and GSTM1 polymorphisms were independent variables related to mercury body burdens (CATREG P<0.05). GSTP1-114/GSTT1 and GSTP1-105/GCLC combinations showed synergistic effects on hair mercury levels compared to single-gene variants. CONCLUSIONS We found evidence that certain genetic backgrounds were associated with lead and mercury metabolism, suggesting gene-environment and gene-gene-environment interactions. The modes of interaction remain to be evaluated.
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Affiliation(s)
- Claudia Gundacker
- Medical University of Vienna, Center for Public Health, Lab Ecotoxicology, Waehringer Strasse 10, A-1090 Vienna, Austria.
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Park SK, Hu H, Wright RO, Schwartz J, Cheng Y, Sparrow D, Vokonas PS, Weisskopf MG. Iron metabolism genes, low-level lead exposure, and QT interval. ENVIRONMENTAL HEALTH PERSPECTIVES 2009; 117:80-5. [PMID: 19165391 PMCID: PMC2627870 DOI: 10.1289/ehp.11559] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2008] [Accepted: 08/22/2008] [Indexed: 05/22/2023]
Abstract
BACKGROUND Cumulative exposure to lead has been shown to be associated with depression of electrocardiographic conduction, such as QT interval (time from start of the Q wave to end of the T wave). Because iron can enhance the oxidative effects of lead, we examined whether polymorphisms in iron metabolism genes [hemochromatosis (HFE), transferrin (TF) C2, and heme oxygenase-1 (HMOX-1)] increase susceptibility to the effects of lead on QT interval in 613 community-dwelling older men. METHODS We used standard 12-lead electrocardiograms, K-shell X-ray fluorescence, and graphite furnace atomic absorption spectrometry to measure QT interval, bone lead, and blood lead levels, respectively. RESULTS A one-interquartile-range increase in tibia lead level (13 mug/g) was associated with a 11.35-msec [95% confidence interval (CI), 4.05-18.65 msec] and a 6.81-msec (95% CI, 1.67-11.95 msec) increase in the heart-rate-corrected QT interval among persons carrying long HMOX-1 alleles and at least one copy of an HFE variant, respectively, but had no effect in persons with short and middle HMOX-1 alleles and the wild-type HFE genotype. The lengthening of the heart-rate-corrected QT interval with higher tibia lead and blood lead became more pronounced as the total number (0 vs. 1 vs. >/=2) of gene variants increased (tibia, p-trend = 0.01; blood, p-trend = 0.04). This synergy seems to be driven by a joint effect between HFE variant and HMOX-1 L alleles. CONCLUSION We found evidence that gene variants related to iron metabolism increase the impacts of low-level lead exposure on the prolonged QT interval. This is the first such report, so these results should be interpreted cautiously and need to be independently verified.
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Affiliation(s)
- Sung Kyun Park
- Department of Environmental Health Sciences, University of Michigan School of Public Health, Ann Arbor, Michigan 48109, USA.
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Hopkins MR, Ettinger AS, Hernández-Avila M, Schwartz J, Téllez-Rojo MM, Lamadrid-Figueroa H, Bellinger D, Hu H, Wright RO. Variants in iron metabolism genes predict higher blood lead levels in young children. ENVIRONMENTAL HEALTH PERSPECTIVES 2008; 116:1261-6. [PMID: 18795173 PMCID: PMC2535632 DOI: 10.1289/ehp.11233] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/03/2008] [Accepted: 04/23/2008] [Indexed: 05/21/2023]
Abstract
BACKGROUND Given the association between iron deficiency and lead absorption, we hypothesized that variants in iron metabolism genes would predict higher blood lead levels in young children. OBJECTIVE We examined the association between common missense variants in the hemochromatosis (HFE) and transferrin (TF) genes and blood lead levels in 422 Mexican children. METHODS Archived umbilical cord blood samples were genotyped for HFE (H63D and C282Y) and TF (P570S) variants. Blood lead was measured at 24, 30, 36, 42, and 48 months of age. A total of 341 subjects had at least one follow-up blood lead level available and data available on covariates of interest for inclusion in the longitudinal analyses. We used random-effects models to examine the associations between genotype (HFE, TF, and combined HFE + TF) and repeated measures of blood lead, adjusting for maternal blood lead at delivery and child's concurrent anemia status. RESULTS Of 422 children genotyped, 17.7, 3.3, and 18.9% carried the HFE H63D, HFE C282Y, and TF P570S variants, respectively. One percent of children carried both the HFE C282Y and TF P570S variants, and 3% of children carried both the HFE H63D and TF P570S variants. On average, carriers of either the HFE (beta = 0.11, p = 0.04) or TF (beta = 0.10, p = 0.08) variant had blood lead levels that were 11% and 10% higher, respectively, than wild-type subjects. In models examining the dose effect, subjects carrying both variants (beta = 0.41, p = 0.006) had blood lead 50% higher than wild-type subjects and a significantly higher odds of having a blood lead level > 10 microg/dL (odds ratio = 18.3; 95% confidence interval, 1.9-177.1). CONCLUSIONS Iron metabolism gene variants modify lead metabolism such that HFE variants are associated with increased blood lead levels in young children. The joint presence of variant alleles in the HFE and TF genes showed the greatest effect, suggesting a gene-by-gene-by-environment interaction.
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Affiliation(s)
- Marianne R. Hopkins
- Department of Environmental Health, Harvard School of Public Health, Boston, Massachusetts, USA
- Department of Medicine, Children’s Hospital Boston, Boston, Massachusetts, USA
| | - Adrienne S. Ettinger
- Department of Environmental Health, Harvard School of Public Health, Boston, Massachusetts, USA
- Channing Laboratory, Brigham and Women’s Hospital, Boston, Massachusetts, USA
- Department of Environmental Health Sciences, University of Michigan School of Public Health, Ann Arbor, Michigan, USA
- Address correspondence to A.S. Ettinger, Harvard School of Public Health, HSPH Landmark Center, 401 Park Dr., Rm. 421-West, Boston, MA 02215 USA. Telephone: (617) 384-8834. Fax: (617) 384-8745. E-mail:
| | | | - Joel Schwartz
- Department of Environmental Health, Harvard School of Public Health, Boston, Massachusetts, USA
- Channing Laboratory, Brigham and Women’s Hospital, Boston, Massachusetts, USA
| | - Martha María Téllez-Rojo
- Division of Program Evaluation and Biostatistics, Center of Evaluation Research and Surveys, National Institute of Public Health, Cuernavaca, Morelos, Mexico
| | - Héctor Lamadrid-Figueroa
- Division of Program Evaluation and Biostatistics, Center of Evaluation Research and Surveys, National Institute of Public Health, Cuernavaca, Morelos, Mexico
| | - David Bellinger
- Department of Environmental Health, Harvard School of Public Health, Boston, Massachusetts, USA
- Department of Neurology, Children’s Hospital Boston, Boston, Massachusetts, USA
| | - Howard Hu
- Department of Environmental Health, Harvard School of Public Health, Boston, Massachusetts, USA
- Department of Environmental Health Sciences, University of Michigan School of Public Health, Ann Arbor, Michigan, USA
| | - Robert O. Wright
- Department of Environmental Health, Harvard School of Public Health, Boston, Massachusetts, USA
- Department of Medicine, Children’s Hospital Boston, Boston, Massachusetts, USA
- Channing Laboratory, Brigham and Women’s Hospital, Boston, Massachusetts, USA
- Department of Environmental Health Sciences, University of Michigan School of Public Health, Ann Arbor, Michigan, USA
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Whitfield JB, Dy V, McQuilty R, Zhu G, Montgomery GW, Ferreira MAR, Duffy DL, Neale MC, Heijmans BT, Heath AC, Martin NG. Evidence of genetic effects on blood lead concentration. ENVIRONMENTAL HEALTH PERSPECTIVES 2007; 115:1224-30. [PMID: 17687451 PMCID: PMC1940084 DOI: 10.1289/ehp.8847] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2005] [Accepted: 06/14/2007] [Indexed: 05/04/2023]
Abstract
BACKGROUND Lead is an environmental pollutant that causes acute and chronic toxicity. Surveys have related mean blood lead concentrations to exogenous sources, including industrial activity, use of lead-based paints, or traffic density. However, there has been little investigation of individual differences in lead absorption, distribution, or toxicity, or of genetic causes of such variation. OBJECTIVES We assessed the genetic contribution to variation in blood lead concentration in adults and conducted a preliminary search for genes producing such variation. METHODS Erythrocyte lead concentration was measured by inductively coupled plasma mass spectrometry in venous blood samples from 2,926 Australian adult male and female twins. Mean lead concentrations were compared by place of residence, social class and education, and by the subjects' age, sex, alcohol intake, smoking habits, iron status, and HFE genotype. RESULTS After adjustment for these covariates, there was strong evidence of genetic effects but not for shared environmental effects persisting into adult life. Linkage analysis showed suggestive evidence (logarithm of odds = 2.63, genome-wide p = 0.170) for a quantitative trait locus affecting blood lead values on chromosome 3 with the linkage peak close to SLC4A7, a gene whose product affects lead transport. CONCLUSIONS We conclude that genetic variation plays a significant role in determining lead absorption, lead distribution within the body, or both.
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Affiliation(s)
- John B Whitfield
- Department of Clinical Biochemistry, Royal Prince Alfred Hospital, Sydney, Australia.
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Wang FT, Hu H, Schwartz J, Weuve J, Spiro AS, Sparrow D, Nie H, Silverman EK, Weiss ST, Wright RO. Modifying effects of the HFE polymorphisms on the association between lead burden and cognitive decline. ENVIRONMENTAL HEALTH PERSPECTIVES 2007; 115:1210-5. [PMID: 17687449 PMCID: PMC1940090 DOI: 10.1289/ehp.9855] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/25/2006] [Accepted: 05/10/2007] [Indexed: 05/16/2023]
Abstract
BACKGROUND As iron and lead promote oxidative damage, and hemochromatosis (HFE) gene polymorphisms increase body iron burden, HFE variant alleles may modify the lead burden and cognitive decline relationship. OBJECTIVE Our goal was to assess the modifying effects of HFE variants on the lead burden and cognitive decline relation in older adults. METHODS We measured tibia and patella lead using K-X-ray fluorescence (1991-1999) among participants of the Normative Aging Study, a longitudinal study of community-dwelling men from greater Boston. We assessed cognitive function with the Mini-Mental State Examination (MMSE) twice (1993-1998 and 1995-2000) and genotyped participants for HFE polymorphisms. We estimated the adjusted mean differences in lead-associated annual cognitive decline across HFE genotype groups (n = 358). RESULTS Higher tibia lead was associated with steeper cognitive decline among participants with at least one HFE variant allele compared with men with only wild-type alleles (p interaction = 0.03), such that a 15 microg/g increase in tibia lead was associated with a 0.2 point annual decrement in MMSE score among HFE variant allele carriers. This difference in scores among men with at least one variant allele was comparable to the difference in baseline MMSE scores that we observed among men who were 4 years apart in age. Moreover, the deleterious association between tibia lead and cognitive decline appeared progressively worse in participants with increasingly more copies of HFE variant alleles (p-trend = 0.008). Results for patella lead were similar. CONCLUSION Our findings suggest that HFE polymorphisms greatly enhance susceptibility to lead-related cognitive impairment in a pattern consistent with allelelic dose.
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Affiliation(s)
- Florence T Wang
- Department of Environmental Health, Harvard School of Public Health, Boston, Massachusetts, USA.
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35
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Park SK, O'Neill MS, Wright RO, Hu H, Vokonas PS, Sparrow D, Suh H, Schwartz J. HFE
Genotype, Particulate Air Pollution, and Heart Rate Variability. Circulation 2006; 114:2798-805. [PMID: 17145987 DOI: 10.1161/circulationaha.106.643197] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background—
Particulate air pollution has been associated with cardiovascular mortality and morbidity. Transition metals such as iron bound to the particles may be responsible for those associations. The protein product of the hemochromatosis (
HFE
) gene modulates uptake of iron and divalent cations from pulmonary sources and reduces their toxicity. Two
HFE
polymorphisms (C282Y and H63D) associated with increased iron uptake may modify the effect of metal-rich particles on the cardiovascular system.
Methods and Results—
We investigated the association between particulate matter ≤2.5 μm in aerodynamic diameter and heart rate variability in 518 older men from the Normative Aging Study who were examined between November 2000 and December 2004. Linear regression models were fit to evaluate interactions between
HFE
genotype and particulate matter ≤2.5 μm in aerodynamic diameter in relation to heart rate variability, controlling for potential confounders. A 10-μg/m
3
increase in particulate matter ≤2.5 μm in aerodynamic diameter during the 48 hours before heart rate variability measurement was associated with a 31.7% (95% CI, 10.3% to 48.1%) decrease in the high-frequency component of heart rate variability in persons with the wild-type genotype, whereas no relationship in the high-frequency component was observed in persons with either
HFE
variant. The difference in effect of particulate matter ≤2.5 μm in aerodynamic diameter on the high-frequency component between persons with and without
HFE
variants was significant (
P
for interaction=0.02).
Conclusions—
The effect of particles on cardiac autonomic function was shielded in subjects with at least 1 copy of an
HFE
variant compared with wild-type subjects. Transition metals, including iron, bound to ambient particles and the related oxidative stress may play an important role in cardiac toxicity of particles.
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Affiliation(s)
- Sung Kyun Park
- Department of Environmental Health, Harvard School of Public Health, Boston, Mass, USA.
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36
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Bellinger DC. Interpretation of small effect sizes in occupational and environmental neurotoxicology: individual versus population risk. Neurotoxicology 2006; 28:245-51. [PMID: 16806481 DOI: 10.1016/j.neuro.2006.05.009] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2005] [Revised: 05/16/2006] [Accepted: 05/17/2006] [Indexed: 11/23/2022]
Abstract
Some have questioned the importance of the small effect sizes generally reported in epidemiological studies of neurotoxicity. To some extent, this reflects a failure to appreciate the critical distinction between individual and population risk. In the first part of the paper, arguments are marshaled to support the contention that small shifts in the mean value of a health index within a study sample can, under some circumstances, carry substantial implications for the health status of the population from which the study sample was drawn. Under such circumstances, a population-based approach to prevention might be as effective as a patient-based approach. The second part clarifies conditions under which this will be true (e.g., a monotonic relationship between a health index and risk of disease) and conditions under which it might not (e.g., a J-shaped relationship). In the third part, the relative levels of uncertainty in characterizing individual versus population risk are explored. In neurotoxicological studies, uncertainty in characterizing individual risk could be reduced by adjusting, in addition to bone fide confounders, for covariates that are strong predictors of outcome and by more assiduous efforts to characterize major effect modifiers.
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Affiliation(s)
- David C Bellinger
- Children's Hospital Boston, Harvard Medical School, Farley Basement Box 127, 300 Longwood Avenue, Boston, MA 02115, USA.
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37
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Joseph CLM, Havstad S, Ownby DR, Peterson EL, Maliarik M, McCabe MJ, Barone C, Johnson CC. Blood lead level and risk of asthma. ENVIRONMENTAL HEALTH PERSPECTIVES 2005; 113:900-4. [PMID: 16002380 PMCID: PMC1257653 DOI: 10.1289/ehp.7453] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2004] [Accepted: 03/03/2005] [Indexed: 05/03/2023]
Abstract
Asthma and lead poisoning are prevalent among urban children in the United States. Lead exposure may be associated with excessive production of immunoglobulin E, possibly increasing asthma risk and contributing to racial disparities. The objective of this study was to examine racial differences in the association of blood lead level (BLL) to risk of developing asthma. We established and followed a cohort prospectively to determine asthma onset, using patient encounters and drug claims obtained from hospital databases. Participants were managed care enrollees with BLL measured and documented at 1-3 years of age. We used multiple variable analysis techniques to determine the relationship of BLL to period prevalent and incident asthma. Of the 4,634 children screened for lead from 1995 through 1998, 69.5% were African American, 50.5% were male, and mean age was 1.2 years. Among African Americans, BLL > or = 5 and BLL > or = 10 microg/dL were not associated with asthma. The association of BLL > or = 5 microg/dL with asthma among Caucasians was slightly elevated, but not significant [adjusted hazard ratio (adjHR) = 1.4; 95% confidence interval (CI), 0.7-2.9; p = 0.40]. Despite the small number of Caucasians with high BLL, the adjHR increased to 2.7 (95% CI, 0.9-8.1; p = 0.09) when more stringent criteria for asthma were used. When compared with Caucasians with BLL < 5 microg/dL, African Americans were at a significantly increased risk of asthma regardless of BLL (adjHR = 1.4-3.0). We conclude that an effect of BLL on risk of asthma for African Americans was not observed. These results demonstrate the need for further exploration of the complex interrelationships between race, asthma phenotype, genetic susceptibilities, and socioenvironmental exposures, including lead.
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Affiliation(s)
- Christine L M Joseph
- Department of Biostatistics and Research Epidemiology, Henry Ford Health System, Detroit, Michigan 48202, USA.
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