Dataset Information

Blood lead concentration and thyroid function during pregnancy: results from the Yugoslavia Prospective Study of Environmental Lead Exposure.

ABSTRACT:

Background

Although maternal hypothyroidism increases the risk of adverse neonatal and obstetric outcomes as well as lower IQ in children, the environmental determinants of maternal thyroid dysfunction have yet to be fully explored.

Objectives

We aimed to examine associations between mid-pregnancy blood lead (BPb) and concomitant measures of thyroid function among participants in the Yugoslavia Prospective Study of Environmental Lead Exposure.

Methods

As part of a population-based prospective study of two towns in Kosovo-one with high levels of environmental lead and one with low-women were recruited during the second trimester of pregnancy, at which time blood samples and questionnaire data were collected. We measured concentrations of BPb, free thyroxine (FT4), thyroid-stimulating hormone (TSH), and thyroid peroxidase antibodies (TPOAb) in archived serum samples.

Results

Compared with women from the unexposed town, women from the exposed town had lower mean FT4 (0.91 ± 0.17 vs. 1.03 ± 0.16 ng/dL), higher mean TPOAb (15.45 ± 33.08 vs. 5.12 ± 6.38 IU/mL), and higher mean BPb (20.00 ± 6.99 vs. 5.57 ± 2.01 μg/dL). No differences in TSH levels were found. After adjustment for potential confounders, for each natural log unit increase in BPb, FT4 decreased by 0.074 ng/dL (95% CI: -0.10, -0.046 ng/dL), and the odds ratio for testing positive to TPOAb was 2.41 (95% CI: 1.53, 3.82). We found no association between BPb and TSH.

Conclusions

Prolonged lead exposure may contribute to maternal thyroid dysfunction by stimulating autoimmunity to the thyroid gland.

SUBMITTER: Kahn LG

PROVIDER: S-EPMC4181923 | biostudies-literature | 2014 Oct

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Blood lead concentration and thyroid function during pregnancy: results from the Yugoslavia Prospective Study of Environmental Lead Exposure.

Kahn Linda G LG Liu Xinhua X Rajovic Biljana B Popovac Dusan D Oberfield Sharon S Graziano Joseph H JH Factor-Litvak Pam P

Environmental health perspectives 20140527 10

<h4>Background</h4>Although maternal hypothyroidism increases the risk of adverse neonatal and obstetric outcomes as well as lower IQ in children, the environmental determinants of maternal thyroid dysfunction have yet to be fully explored.<h4>Objectives</h4>We aimed to examine associations between mid-pregnancy blood lead (BPb) and concomitant measures of thyroid function among participants in the Yugoslavia Prospective Study of Environmental Lead Exposure.<h4>Methods</h4>As part of a populatio ...[more]

PMID: 24866691

Similar Datasets

Project description:BackgroundIngestion and inhalation are common routes of exposure for lead in humans. Developing countries still have unacceptably high rates of lead toxicity, especially in children. Studies on probable risk factors of lead poisoning in Iranian children are insufficient. In this study, we aimed to evaluate possible environmental factors in children with high blood lead concentrations living in Tehran and neighboring cities.MethodsIn a prospective cross-sectional study between March 2018 and March 2019 we followed all children referred from two pediatric gastrointestinal clinics with blood lead level (BLL) > 5 μg/dL in metropolitan Tehran to investigate possible environmental risk factors in their home. Household specimens including scratched wall paint, house floor dust, windowsill dust, tap water, and consumed spice were evaluated using atomic absorption method to detect lead concentrations. Epidemiological and environmental data collected through in-depth interviews with parents/guardians. Industrial areas were defined based on municipality maps on industrial places.ResultsThirty of 56 parents/guardians with BLL > 5 μg/dL agreed to be followed through environmental investigation. The only categorical statistically significant risk factor was a history of lead poisoning in the family and living in an industrial zone. There was a positive correlation between BLL and interior windowsills dust lead level, r = 0.46, p = 0.01. Scratched paint lead level and BLL showed a significant positive correlation, r = 0.50, p = 0.005. House floor dust lead level (median = 77.4, p < 0.001) and interior windowsill dust lead level (median = 291, p = 0.011) were both significantly higher than the environmental protection agency (EPA) standards of 40 μg/ft2, 250 μg/ft2. Interior windowsill dust lead concentrations were significantly higher in industrial areas (p = 0.026).ConclusionChildren's playing environment should be cleaned more often to reduce dust. Moreover, specific rules may need to be implemented for paint lead concentrations and air pollution, especially in industrial areas.

Project description:INTRODUCTION:Lead (Pb) crosses the placenta and can cause oxidative stress, reduced fetal growth and neurological problems. The principal source of oxidative stress in human cells is mitochondria. Therefore, disruption of normal mitochondrial function during pregnancy may represent a primary mechanism behind the adverse effects of lead. We sought to assess the association of Pb exposure during pregnancy with mitochondrial DNA (mtDNA) content, a sensitive marker of mitochondrial function, in cord blood. MATERIALS AND METHODS:This study comprised mother-infant pairs from the Programming Research in Obesity, Growth, Environment and Social Stressors (PROGRESS) study, a prospective birth-cohort that enrolled 1050 pregnant women from Mexico City who were receiving prenatal care between December 2007 and July 2011. Quantitative PCR was used to calculate relative MtDNA content (mitochondrial-to-nuclear DNA ratio (mtDNA/nDNA)) in cord blood. Lead concentrations in both maternal blood (2nd and 3rd trimester and at delivery day) and in cord blood were measured by ICP-MS. Multivariable regression models adjusting for multiple confounders were fitted with 410 mother-infant pairs for whom complete data for mtDNA content, lead levels, and covariates were available. RESULTS:Maternal blood Pb measured in the second (mean 3.79??g/dL, SD 2.63; ??=?0.059, 95% CI 0.008, 0.111) and third trimester (mean 3.90??g/dL; SD 2.84; ??=?0.054, 95% CI 0.002, 0.107) during pregnancy and PB in cord blood (mean 3.50??g/dL, SD 2.59; ??=?0.050, 95% CI 0.004; 0.096) were associated with increased cord blood mtDNA content (mean 1.46, SD 0.44). In two-way interaction analyses, cord blood Pb marginally interacted with gestational age leading to an increase in mtDNA content for pre-term births (Benjamini-Hochberg False Discovery Rate correction; BH-FDR?=?0.08). CONCLUSION:This study shows that lead exposure in pregnancy alters mtDNA content in cord blood; therefore, alteration of mtDNA content might be a mechanism underlying the toxicity of lead.

Project description:Impaired thyroid function is a common side effect of lithium medication. Recent data indicate that lithium exposure through drinking water, although providing much lower doses than the medication, may also affect thyroid hormone levels. However, the effects in susceptible groups like pregnant women are not known.In a population-based mother-child cohort in the Argentinean Andes (n?=?194), an area with varying concentrations of lithium in the drinking water, we assessed lithium exposure repeatedly during pregnancy by measuring the concentrations in blood using inductively coupled plasma mass spectrometry. The markers of thyroid function included thyrotropin (TSH), free/total thyroxine (fT4/T4), free/total triiodothyronine (fT3/T3), thyroglobulin, and transthyretin in serum, sampled at the same time. Multiple potential confounders, including exposure to arsenic, cesium, and boron (elevated in water) as well as selenium and iodine (essential for thyroid function) were considered.The lithium concentrations in blood [median 25??g/L (0.0036?mmol/L); range 1.9-145??g/L (0.000027-0.021?mmol/L)] correlated significantly with those in urine and drinking water (rs?=?0.84, p?<?0.001, and rs?=?0.40, p?<?0.001, respectively). Using linear quantile regression models, we found a positive association between blood lithium (log2 transformed) and TSH concentrations, particularly in the lowest percentiles of TSH (B?=?0.20?mIU/L, [95% confidence interval 0.048-0.35] at the fifth percentile). We also found inverse associations of blood lithium with transthyretin, particularly at the highest percentiles, as well as with fT3 and T3, with less obvious variation across percentiles. Unexpectedly, blood cesium concentrations (median 111??g/L, range 2.5-711??g/L) were also inversely associated with fT3 and T3, particularly at the highest T3 percentiles, but not with TSH or transthyretin. Arsenic and boron exposure (also through drinking water) did not show any associations with the thyroid parameters.The study supports previous findings that lithium exposure through drinking water may impair thyroid function. The results regarding cesium exposure through drinking water are new. During pregnancy, impaired thyroid function may be detrimental for fetal development. The findings reinforce the need for better control of drinking water, including bottled water, as well as a health-based guideline value.

Project description:Polycyclic aromatic hydrocarbons (PAHs) are byproducts of incomplete combustion reactions and are ubiquitous in the environment, leading to widespread human exposure via inhalation and ingestion pathways. PAHs have been implicated as endocrine disrupting compounds in previous animal and in vitro studies, but human studies are currently lacking. Pregnant women and their developing fetuses are particularly susceptible populations to environmental contaminants, in part because alterations in hormone physiology during gestation can have adverse consequences on the health of the pregnancy. We utilized data on 659 pregnant women from the PROTECT longitudinal birth cohort in Puerto Rico to assess associations between repeated measures of 8 urinary hydroxylated PAH (OH-PAH) metabolites and 9 serum hormones during gestation. Urine samples were collected at 3 study visits (median gestational ages of 18, 22, and 26 weeks at each visit, respectively) and serum samples were collected at the first and third study visits. Linear mixed effects models were used to ascertain longitudinal associations between OH-PAHs and hormones, and sensitivity analyses were employed to assess potential nonlinearity and differences in associations on the basis of fetal sex and timing of biomarker measurement. Among the multiple positive associations we observed between OH-PAHs and CRH, estriol, progesterone, T3, and the ratio of T3 to T4, and inverse associations with testosterone, the most notable are a 24.3% increase (95% CI: 13.0, 36.7) in CRH with an interquartile range (IQR) increase in 1-hydroxyphenanthrene and a 17.2% decrease (95% CI: 8.13, 25.4) in testosterone with an IQR increase in 1-hydroxynapthalene. Many associations observed were dependent on fetal sex, and some relationships showed evidence of nonlinearity. These findings demonstrate the importance of studying PAH exposures during pregnancy and highlight the potential complexity of their impacts on the physiology of human pregnancy.

Dataset Information

Blood lead concentration and thyroid function during pregnancy: results from the Yugoslavia Prospective Study of Environmental Lead Exposure.

Background

Objectives

Methods

Results

Conclusions

Publications

Blood lead concentration and thyroid function during pregnancy: results from the Yugoslavia Prospective Study of Environmental Lead Exposure.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets