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Lead (Pb) and neurodevelopment: A review on exposure and biomarkers of effect (BDNF, HDL) and susceptibility. Int J Hyg Environ Health 2021; 238:113855. [PMID: 34655857 DOI: 10.1016/j.ijheh.2021.113855] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Revised: 09/29/2021] [Accepted: 10/01/2021] [Indexed: 12/13/2022]
Abstract
Lead (Pb) is a ubiquitous environmental pollutant and a potent toxic compound. Humans are exposed to Pb through inhalation, ingestion, and skin contact via food, water, tobacco smoke, air, dust, and soil. Pb accumulates in bones, brain, liver and kidney. Fetal exposure occurs via transplacental transmission. The most critical health effects are developmental neurotoxicity in infants and cardiovascular effects and nephrotoxicity in adults. Pb exposure has been steadily decreasing over the past decades, but there are few recent exposure data from the general European population; moreover, no safe Pb limit has been set. Sensitive biomarkers of exposure, effect and susceptibility, that reliably and timely indicate Pb-associated toxicity are required to assess human exposure-health relationships in a situation of low to moderate exposure. Therefore, a systematic literature review based on PubMed entries published before July 2019 that addressed Pb exposure and biomarkers of effect and susceptibility, neurodevelopmental toxicity, epigenetic modifications, and transcriptomics was conducted. Finally included were 58 original papers on Pb exposure and 17 studies on biomarkers. The biomarkers that are linked to Pb exposure and neurodevelopment were grouped into effect biomarkers (serum brain-derived neurotrophic factor (BDNF) and serum/saliva cortisol), susceptibility markers (epigenetic markers and gene sequence variants) and other biomarkers (serum high-density lipoprotein (HDL), maternal iron (Fe) and calcium (Ca) status). Serum BDNF and plasma HDL are potential candidates to be further validated as effect markers for routine use in HBM studies of Pb, complemented by markers of Fe and Ca status to also address nutritional interactions related to neurodevelopmental disorders. For several markers, a causal relationship with Pb-induced neurodevelopmental toxicity is likely. Results on BDNF are discussed in relation to Adverse Outcome Pathway (AOP) 13 ("Chronic binding of antagonist to N-methyl-D-aspartate receptors (NMDARs) during brain development induces impairment of learning and memory abilities") of the AOP-Wiki. Further studies are needed to validate sensitive, reliable, and timely effect biomarkers, especially for low to moderate Pb exposure scenarios.
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Kordas K, Burganowski R, Roy A, Peregalli F, Baccino V, Barcia E, Mangieri S, Ocampo V, Mañay N, Martínez G, Vahter M, Queirolo EI. Nutritional status and diet as predictors of children's lead concentrations in blood and urine. ENVIRONMENT INTERNATIONAL 2018; 111:43-51. [PMID: 29172090 PMCID: PMC5915341 DOI: 10.1016/j.envint.2017.11.013] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2017] [Revised: 10/17/2017] [Accepted: 11/17/2017] [Indexed: 05/05/2023]
Abstract
Lead exposure remains an important public health problem. Contaminated foods may act as a source of lead exposure, while certain nutrients may reduce lead absorption. We examined the cross-sectional associations of dietary patterns and the intake of several nutrients and foods with blood (Pb-B) and urinary (Pb-U) lead concentrations in children (5-8y) from Montevideo, Uruguay. From two 24-hour recalls completed by caregivers, we derived the mean daily intake of select nutrients and food groups (dairy, milk, fruit, root vegetables, foods rich in heme and non-heme iron), as well as "nutrient dense" and "processed" food patterns. Pb-B (n=315) was measured using atomic absorption spectrometry; Pb-U (n=321) using ICP-MS. Pb-U was adjusted for specific gravity and log-transformed to approximate a normal distribution. Iron deficiency (ID) and dietary variables were tested as predictors of Pb-B and log-Pb-U in covariate-adjusted regressions. Median [5%, 95%] Pb-B and Pb-U were 3.8 [0.8-7.8] μg/dL and 1.9 [0.6-5.1] μg/L, respectively; ~25% of Pb-B above current U.S. CDC reference concentration of 5μg/dL. ID was associated with 0.75μg/dL higher Pb-B, compared to non-ID (p<0.05). Consumption of root vegetables was not associated with Pb-B or log-Pb-U. Higher scores on the nutrient-dense pattern were related with higher Pb-Bs, possibly due to consumption of green leafy vegetables. Dietary intake of iron or iron-rich foods was not associated with biomarkers of lead. Conversely, children consuming more calcium, dairy, milk and yogurt had lower Pb-B and log-Pb-U. Our findings appear consistent with existing recommendations on including calcium-rich, but not iron- or vitamin-C-rich foods in the diets of lead-exposed children, especially where the consumption of these foods is low.
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Affiliation(s)
- Katarzyna Kordas
- Epidemiology and Environmental Health, University at Buffalo, Buffalo, NY, United States.
| | - Rachael Burganowski
- Epidemiology and Environmental Health, University at Buffalo, Buffalo, NY, United States
| | - Aditi Roy
- Department of Pediatrics, Vanderbilt University Medical Center, Nashville, TN, United States
| | - Fabiana Peregalli
- Centre for Research, Catholic University of Uruguay, Montevideo, Uruguay; Department of Gastroenterology, Hepatology and Nutrition, Pereira Rossell Hospital, Montevideo, Uruguay
| | - Valentina Baccino
- Centre for Research, Catholic University of Uruguay, Montevideo, Uruguay
| | - Elizabeth Barcia
- Centre for Research, Catholic University of Uruguay, Montevideo, Uruguay
| | - Soledad Mangieri
- Centre for Research, Catholic University of Uruguay, Montevideo, Uruguay
| | - Virginia Ocampo
- Centre for Research, Catholic University of Uruguay, Montevideo, Uruguay
| | - Nelly Mañay
- Toxicology Area, Faculty of Chemistry, University of the Republic of Uruguay, Montevideo, Uruguay
| | - Gabriela Martínez
- Toxicology Area, Faculty of Chemistry, University of the Republic of Uruguay, Montevideo, Uruguay
| | - Marie Vahter
- Institute of Environmental Health, Karolinska Institutet, Stockholm, Sweden
| | - Elena I Queirolo
- Centre for Research, Catholic University of Uruguay, Montevideo, Uruguay
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Bello-Manga H, DeBaun MR, Kassim AA. Epidemiology and treatment of relative anemia in children with sickle cell disease in sub-Saharan Africa. Expert Rev Hematol 2016; 9:1031-1042. [PMID: 27677923 DOI: 10.1080/17474086.2016.1240612] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
INTRODUCTION Sickle cell disease (SCD) is the most common inherited hemoglobinopathy in the world, with the majority of cases in sub-Saharan Africa. Concomitant nutritional deficiencies, infections or exposure to environmental toxins exacerbate chronic anemia in children with SCD. The resulting relative anemia is associated with increased risk of strokes, poor cognitive function and impaired growth. It may also attenuate optimal response to hydroxyurea therapy, the only effective and practical treatment option for SCD in sub-Saharan Africa. This review will focus on the epidemiology, clinical sequelae, and treatment of relative anemia in children with SCD living in low and middle-income countries in sub-Saharan Africa. Areas covered: The causes and treatment of relative anemia in children with SCD in sub-Saharan Africa. The MEDLINE database was searched using medical subject headings (MeSH) and keywords for articles regarding relative anemia in children with SCD in sub-Saharan Africa. Expert commentary: Anemia due to nutritional deficiencies and infectious diseases such as helminthiasis and malaria are prevalent in sub-Saharan Africa. Their co-existence in children with SCD increases morbidity and mortality. Therefore, preventing, diagnosing and treating the underlying cause of this relative anemia will improve SCD-related outcomes in children in sub-Saharan Africa.
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Affiliation(s)
- Halima Bello-Manga
- a Department of Hematology and Blood Transfusion , Barau Dikko Teaching hospital/Kaduna State University , Kaduna , Nigeria
| | - Michael R DeBaun
- b Department of Pediatrics, Division of Hematology/Oncology, Vanderbilt-Meharry Center for Excellence in Sickle Cell Disease , Vanderbilt University Medical Center , Nashville , TN , USA
| | - Adetola A Kassim
- c Department of Medicine, Division of Hematology/Oncology, Vanderbilt-Meharry Center for Excellence in Sickle Cell Disease , Vanderbilt University Medical Center , Nashville , TN , USA
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Iron deficiency anaemia and blood lead concentrations in Brazilian children. Trans R Soc Trop Med Hyg 2011; 105:525-30. [PMID: 21742361 DOI: 10.1016/j.trstmh.2011.05.012] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2010] [Revised: 05/26/2011] [Accepted: 05/26/2011] [Indexed: 11/21/2022] Open
Abstract
This study investigated the relationship between iron deficiency/iron deficiency anaemia, assessed by several parameters, and blood lead concentration in children. This cross-sectional study involved 384 Brazilian children, aged 2-11 years, who lived near a lead-manipulating industry. Complete blood counts were obtained by an automated cell counter. Serum iron, total iron binding capacity (TIBC) and ferritin were determined respectively, by colorimetric, turbidimetric methods and chemiluminescence. Blood lead was measured by atomic absorption spectrophotometry. The impact of several parameters for assessment of iron status (haemoglobin, serum iron, TIBC, transferrin saturation, ferritin, red cell indices and red cell distribution width) and variables (gender, age, mother's education, income, body mass index, iron intake, and distance from home to lead-manipulating industry) on blood lead concentration was determined by multiple linear regression. There were significant negative associations between blood lead and the distance from home to the lead-manipulating industry (P<0.001), Hb (P=0.019), and ferritin (P=0.023) (R(2)=0.14). Based on these results, further epidemiological studies are necessary to investigate the impact of interventions like iron supplementation or fortification, as an attempt to decrease blood lead in children.
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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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Konofal E, Cortese S. Lead and neuroprotection by iron in ADHD. ENVIRONMENTAL HEALTH PERSPECTIVES 2007; 115:A398-9; author reply A399. [PMID: 17687422 PMCID: PMC1940080 DOI: 10.1289/ehp.10304] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
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Quiterio SL, Moreira FR, da Silva CRS, Arbilla G, Araújo UC, Mattos RDCODC. Avaliação da poluição ambiental causada por particulado de chumbo emitido por uma reformadora de baterias na cidade do Rio de Janeiro, Brasil. CAD SAUDE PUBLICA 2006; 22:1817-23. [PMID: 16917578 DOI: 10.1590/s0102-311x2006000900012] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2005] [Accepted: 01/10/2006] [Indexed: 11/21/2022] Open
Abstract
Neste estudo, determinou-se o teor de chumbo (Pb) presente no ar ao redor de uma reformadora de baterias, antes e após da instalação do sistema de exaustão. Na área externa à reformadora de baterias, as amostras foram coletadas em seis e quatro pontos localizados a aproximadamente 25m e 500m, respectivamente, da reformadora de baterias. Os resultados obtidos mostram que o limite para Pb no ar atmosférico de 1,5µg Pb.m-3 foi excedido em 50% nas amostras coletadas, variando de 0,07 a 183,3µg Pb.m-3. Assim, após algumas modificações na distribuição das atividades no interior da reformadora de baterias e a colocação do sistema de exaustão foram selecionados três pontos de coleta, que correspondiam àqueles mais críticos encontrados nas avaliações anteriores do ar externo. As novas concentrações de chumbo variaram de 0,8 a 17,6µg Pb.m-3, demonstrando que houve uma significativa redução dos níveis de chumbo emitidos para o ambiente após a instalação do sistema de exaustão.
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Affiliation(s)
- Simone Lorena Quiterio
- Instituto de Química, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Rio de Janeiro, Brasil
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Zimmermann MB, Muthayya S, Moretti D, Kurpad A, Hurrell RF. Iron fortification reduces blood lead levels in children in Bangalore, India. Pediatrics 2006; 117:2014-21. [PMID: 16740843 DOI: 10.1542/peds.2005-2440] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
OBJECTIVE Chronic lead poisoning and iron deficiency are concentrated in urban children from lower socioeconomic strata, and both impair neurocognitive development. Our study objective was to determine if iron fortification reduces blood lead levels in urban, lead-exposed, iron-deficient children in Bangalore, India. DESIGN, SETTING, AND PARTICIPANTS A randomized, double-blind, controlled school-based feeding trial was done in 5- to 13-year-old iron-deficient children (n = 186). At baseline, a high prevalence of lead poisoning was found in the younger children. Subsequently, all 5- to 9-year-old children participating in the trial (n = 134) were followed to determine if iron fortification would affect their blood lead levels. INTERVENTION Children were dewormed and fed 6 days/week for 16 weeks either an iron-fortified rice meal (approximately 15 mg of iron per day as ferric pyrophosphate) or an identical control meal without added iron. Feeding was directly supervised and compliance monitored. OUTCOME MEASURES Hemoglobin, serum ferritin, C-reactive protein, transferrin receptor, zinc protoporphyrin, and blood lead concentrations were measured. RESULTS The prevalence of iron deficiency was significantly reduced in the iron group (from 70% to 28%) compared with the control group (76% to 55%). There was a significant decrease in median blood lead concentration in the iron group compared with the control group. The prevalence of blood lead levels > or =10 microg/dL was significantly reduced in the iron group (from 65% to 29%) compared with the control group (68% to 55%). CONCLUSIONS Our findings suggest providing iron in a fortified food to lead-exposed children may reduce chronic lead intoxication. Iron fortification may be an effective and sustainable strategy to accompany environmental lead abatement.
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Affiliation(s)
- Michael B Zimmermann
- Laboratory for Human Nutrition, Swiss Federal Institute of Technology, Zürich, Switzerland.
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Alarcon PA, Lin LH, Noche M, Hernandez VC, Cimafranca L, Lam W, Comer GM. Effect of oral supplementation on catch-up growth in picky eaters. Clin Pediatr (Phila) 2003; 42:209-17. [PMID: 12739919 DOI: 10.1177/000992280304200304] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Ninety-two subjects ages 36 to 60 months who had picky-eater behavior and evidence of growth faltering were randomized to receive either nutrition counseling alone, or nutrition counseling plus a nutritional supplement (Study) for 90 days. The Study group had significantly greater increases in weight and height. There were no significant differences between groups in changes in appetite or activity levels, or in gastrointestinal symptom scores. The percent of subjects who developed upper respiratory tract infections was significantly lower in the Study group. These data suggest that a nutritional supplement in addition to nutrition counseling promote catch-up growth and may contribute to lower rates of infectious disease in children with picky eater behavior.
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Entzel PP, Fleming LE, Trepka MJ, Squicciarini D. The health status of newly arrived refugee children in Miami-Dade County, Florida. Am J Public Health 2003; 93:286-8. [PMID: 12554586 PMCID: PMC1447730 DOI: 10.2105/ajph.93.2.286] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/10/2002] [Indexed: 11/04/2022]
Affiliation(s)
- Pamela P Entzel
- Department of Epidemiology and Public Health, University of Miami School of Medicine, Fla 33136, USA
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Wright RO, Tsaih SW, Schwartz J, Wright RJ, Hu H. Association between iron deficiency and blood lead level in a longitudinal analysis of children followed in an urban primary care clinic. J Pediatr 2003; 142:9-14. [PMID: 12520247 DOI: 10.1067/mpd.2003.mpd0344] [Citation(s) in RCA: 121] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
OBJECTIVE To determine if iron deficiency (ID) is longitudinally associated with lead poisoning. STUDY DESIGN Blood lead levels, hemoglobin, mean corpuscular volume (MCV), red cell distribution width (RDW), insurance status, and age were determined for 1,275 children. ID was defined as MCV <70 fl and RDW >14.5 if age was <2 years and MCV <73 fl and RDW >14.5 if age was >/=2 years. Logistic regression models were constructed by using the second-visit blood lead levels dichotomized at >/=0.48 microm/L (10 microg/dL) as the outcome. RESULTS The odds ratio (OR) for baseline ID predicting lead poisoning at the second visit was 4.12 (95% CI, 1.96-8.65). In the second model, using children who were iron-replete at both visits as the referent group, for children with ID at both visits, the OR for predicting lead poisoning at the second visit was 5.54 (95% CI, 2.25-13.62). For children with ID at the first visit and iron-replete at the second visit, the OR was 2.73 (95% CI, 0.90-8.27), and for children iron-replete at the first visit and ID at the second visit, the OR was 0.81 (95% CI, 0.10-6.30). CONCLUSIONS ID is associated with subsequent lead poisoning. These data are consistent with a biological mechanism of increased lead absorption among iron deficient children.
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Affiliation(s)
- Robert O Wright
- Department of Pediatrics, Children's Hospital, the Channing Laboratory, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA
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Abstract
Anemia is a sign of disease and not a final diagnosis. The clinician's goal is to define the underlying cause. The anemia may be due to decreased production or Increased destruction or loss of red blood cells. Integration of the results of the initial CBC. particularly the RBC indices, the peripheral blood smear, the history and the physical examination can help organize the focus of further evaluations and, ultimately, minimize the number of tests needed to make a firm diagnosis.
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Affiliation(s)
- Michelle L Hermiston
- Division of Pediatric Hematology/Oncology, School of Medicine, University of California San Francisco, San Francisco 94143, USA
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