Body burdens of mercury, lead, selenium and copper among Baltimore newborns

Decreased DNA repair capacity caused by exposure to metal mixtures is modulated by the PARP1 rs1136410 variant in newborns from a polluted metropolitan area

BACKGROUND

DNA damage caused by exposure to metal mixtures and the potential modulating role of genes involved in DNA repair and the antioxidant response have not been evaluated in newborns.

AIM

The aim was to evaluate the association between prenatal exposure to metal mixtures and DNA repair capacity (DRC) in newborns from the Metropolitan Area of Mexico City (MAMC), a heavily polluted area, and the impact of variants in genes involved in DNA repair and the antioxidant response on this association.

METHODS

We analyzed cord blood samples obtained at delivery from 125 healthy newborns from the MAMC. Twenty-four elements were determined by inductively coupled plasma mass spectrometry (ICP‒MS), but only 12 (Cu, I, Se, Zn, As, Ba, Cs, Mn, Sb, Sr, Pb, and Ti) were quantified in most samples. DRC was assessed by the challenge-comet assay, and OGG1, PARP1, and NFE2L2 genotyping was performed with TaqMan probes. Metal mixtures were identified and analyzed using principal component analysis (PCA) and weighted quantile sum (WQS) regression. Independent adjusted linear regression models were used to evaluate the associations.

RESULTS

A null DRC was observed in 46% of newborns. The metals with the highest concentrations were Mn, Sr, Ti, and Pb. Essential elements showed normal levels. Only the mixture characterized by increased As, Cs, Cu, Se, and Zn levels was inversely associated with DRC. As was the principal contributor (37.8%) in the negative direction in the DRC followed by Ba and Sb, according to the WQS regression. Newborns carrying of the derived (G) allele of the PARP1 rs1136410 variant showed decreased DRC by exposure to some potentially toxic metals (PTMs) (As, Cs, and Ba).

CONCLUSION

Prenatal exposure to metal mixtures negatively affected DRC in newborns, and the PARP1 rs1136410 variant had a modulating role in this association.

Determination of toxic metal burden and related risk factors in pregnant women: a biological monitoring in Sabzevar, Iran

Nowadays, the adverse effect of toxic metals on humans is well known, especially in the fetal period such as preventing cognitive development and congenital abnormalities of the central nervous system. Hence, this study aims to evaluate the toxic metal burden in mothers and newborns in Sabzevar. Obtained data can be useful for authorities in public health issues. To determine heavy metals in placental blood and umbilical cord blood, one hundred eighty blood samples were taken from ninety mothers referred to Shahidan Mobini Hospital for delivery. The amount of metals in samples was analyzed using inductively coupled plasma optical emission spectrometry (ICP OES). The results of this study revealed that 21.52%, 26.19%, and 60.71% of maternal blood samples (placental blood) and 16.47%, 56.47%, and 20% of umbilical cord blood samples were higher than the US center for disease control (CDC) recommended levels for Pb, Cd, and As respectively. According to the multiple linear regression analysis, the Pb (p = 0.054), As (p < 0.001), and Se (p < 0.001) levels had an association with the mother's living area. Also, there was a significant association between Se (0.021) and the age of the mother. However, the Se values in its optimum concentrations in the blood (60-140 μg/L) can decrease the adverse effects of toxic metals, 72.5% of the pregnant women had Se values below the 60 μg/L and only 6% of pregnant women had Se levels higher than 140 μg/L. We concluded that the mothers inhabiting the rural areas need more Se sources in their diets.

Maternal and fetal exposure to metal (loid)s, maternal nutrition status, and impact on prenatal growth in an energy rich zone and an urban area along the Persian Gulf

The main purposes of the study were to determine whether maternal and cord blood (MB and CB) levels of metal (loid)s (MLs) are different between industrial and urban areas. Subjects were derived from the petrochemical and gas area (PGA) of Asaluyeh County and the urban area (UA) of Bushehr County in Iran. Adjusted models revealed significant differences between the PGA and UA for maternal Fe, Cu, Mg, Cd, Zn, Ni, V and Pb levels, likewise cord Cu, V, Pb and Ni levels, which were higher in the PGA. Unadjusted models revealed there were decreases in neonatal weight and head circumference by 16.550 g and 0.059 cm, respectively for each Ln unit increase in maternal Cr levels. The mean blood levels of MLs significantly associated with food consumption frequency. The MLs were detected at higher levels in the body's fetuses and their mothers who resided in the PGA than those from the UA. So, the fetuses of mothers living in an industrial areas may be at higher risk from anthropometric measures. The impact of prenatal exposure to MLs on prenatal growth should be considered for better understanding in the further studies.

Oxidative Stress at Birth Is Associated with the Concentration of Iron and Copper in Maternal Serum

Oxidative stress (OS) in the foetal and neonatal periods leads to many disorders in newborns and in later life. The nutritional status of pregnant women is considered to be one of the key factors that triggers OS. We investigated the relationship between the concentration of selected mineral elements in the blood of pregnant women and the concentration of 3′nitrotyrosine (3′NT) as a marker of OS in the umbilical cord blood of newborns. The study group consisted of 57 pregnant women and their newborn children. The concentrations of magnesium (Mg), calcium (Ca), iron (Fe), zinc (Zn) and copper (Cu) in maternal serum (MS) were measured by the flame atomic absorption/emission spectrometry (FAAS/FAES) method. The concentration of 3′NT in umbilical cord serum (UCS) of newborns was determined by the ELISA method. A positive correlation between MS Fe and UCS 3′NT in male newborns was shown (rho = 0.392, p = 0.053). Significantly higher UCS 3′NT was demonstrated in newborns, especially males, whose mothers were characterized by MS Fe higher than 400 μg/dL compared to those of mothers with MS Fe up to 300 μg/dL (p < 0.01). Moreover, a negative correlation between the MS Cu and UCS 3′NT in male newborns was observed (rho = −0.509, p = 0.008). Results of the study showed the need to develop strategies to optimize the nutritional status of pregnant women. Implementation of these strategies could contribute to reducing the risk of pre- and neonatal OS and its adverse health effects in the offspring.

Development of a pregnancy-specific reference material for thyroid biomarkers, vitamin D, and nutritional trace elements in serum

OBJECTIVES

Matrix differences among serum samples from non-pregnant and pregnant patients could bias measurements. Standard Reference Material 1949, Frozen Human Prenatal Serum, was developed to provide a quality assurance material for the measurement of hormones and nutritional elements throughout pregnancy.

METHODS

Serum from non-pregnant women and women in each trimester were bottled into four levels based on pregnancy status and trimester. Liquid chromatography tandem mass spectrometry (LC-MS/MS) methods were developed and applied to the measurement of thyroid hormones, vitamin D metabolites, and vitamin D-binding protein (VDBP). Copper, selenium, and zinc measurements were conducted by inductively coupled plasma dynamic reaction cell MS. Thyroid stimulating hormone (TSH), thyroglobulin (Tg), and thyroglobulin antibody concentrations were analyzed using immunoassays and LC-MS/MS (Tg only).

RESULTS

Certified values for thyroxine and triiodothyronine, reference values for vitamin D metabolites, VDBP, selenium, copper, and zinc, and information values for reverse triiodothyronine, TSH, Tg, and Tg antibodies were assigned. Significant differences in serum concentrations were evident for all analytes across the four levels (p≤0.003). TSH measurements were significantly different (p<0.0001) among research-only immunoassays. Tg concentrations were elevated in research-only immunoassays vs. Federal Drug Administration-approved automated immunoassay and LC-MS/MS. Presence of Tg antibodies increased differences between automated immunoassay and LC-MS/MS.

CONCLUSIONS

The analyte concentrations' changes consistent with the literature and the demonstration of matrix interferences in immunoassay Tg measurements indicate the functionality of this material by providing a relevant matrix-matched reference material for the different stages of pregnancy.

Biomonitoring of maternal and fetal exposure to mercury in Sabzevar and its affecting risk factors

Fetuses and young children are sensitive to even low levels of exposure to Hg, which can damage their brain and adversely affect their central nervous system and cognitive development. This study was conducted to determine the maternal and fetal mercury burden levels in mothers presenting to Shahidan Mobini Hospital for delivery. Eighty-nine mothers were included in this study and 360 samples were taken from their placental tissue and blood (maternal blood) as well as their umbilical cord tissue blood (infant blood). Findings revealed a significant strong correlation (r = 0.890, p < 0.001) in blood mercury between mothers and their infants. According to multiple linear regression analysis, there was a significant positive association between living in rural areas and the level of mercury in the placental tissue (β = 11.09, p < 0.001). This positive association was also found in other samples. In addition, there was a significant association between maternal age and mercury level in the placental tissue (β = 5.56, p = 0.049), placental blood (β = 11.67, p = 0.003), umbilical cord tissue (β = 8.33, p = 0.004) and umbilical cord blood (β = 9.51, p < 0.001).

Blood lead in children and associations with trace elements and sociodemographic factors

BACKGROUND

No safe blood lead concentration in children has been identified. Lead can affect nearly every system in the body and is especially harmful to the developing central nervous system of children. The aim of this study is to analyze blood lead in a population of children and its association with sociodemographic variables, biochemical parameters, copper, iron, selenium and zinc.

METHODS

We recruited 155 children (86 boys and 69 girls) with a mean age of 7.3 (SD:4.1). Blood lead and serum selenium concentrations were measured by electrothermal atomic absorption spectrometry. Serum copper and zinc concentrations were measured by flame atomic absorption spectrometry. Serum iron levels were determined by colorimetric assay. A risk exposure questionnaire for lead was administered to the participants.

RESULTS

The median blood lead level was 1.1 (IQR 0.7-1.6) μg/dL. Regarding risk exposure factors, the youngest children (<2 years) who played outdoors presented a median blood lead concentration of 1.1 μg/dL IQR: 0.48-1.48, compared to the median of 0.3 μg/dL IQR:0.2-0.48 in the children who stated they played at home (p = 0.024). Significant differences were also found when taking into account those parents who smoked (median 1.3 IQR 0.8-1.9 μg/dL vs 0.9 IQR 0.5-1.4 μg/dL of non-smokers, p = 0.002). Children who drank tap water had higher blood lead levels (median 1.2 IQR 0.7-1.6 μg/dL) than those who drank bottled water (median 0.7 IQR 0.2-1.3 μg/dL p = 0.014). In addition, children whose mothers had not finished school had higher blood lead levels (median 1.7 IQR 1.2-2.3 μg/dL) than those whose mothers had finished school (median 1.2 IQR 0.7-1.7 μg/dL) and those whose mothers had gone to university (median 0.9 IQR 0.5-1.4 μg/dL) p = 0.034. In the multivariate lineal regression analysis we continue to observe the association between mother's higher level of education and lower blood levels (p = 0.04) and the interaction between age and outdoor play (p = 0.0145).

CONCLUSIONS

In spite of the decline in blood lead concentrations, associated risk factors continue to exist in vulnerable populations such as children.

Associations of Internal-Migration Status with Maternal Exposure to Stress, Lead, and Selenium Deficiency Among Pregnant Women in Shanghai, China

Internal migration and urbanization are occurring on a global scale. Although the risk of exposure to stress/lead/low selenium is assumed to be high among migrant pregnant women, population-based evidence is limited. This study aims to explore the association of internal-migration status with maternal exposure to lead, low selenium, and stress among pregnant women. A total of 1931 pregnant women were investigated in 2010. The internal-migration status was grouped based on their hukou (registered residence) and length-of-residency in Shanghai. Maternal blood lead and serum selenium concentrations were assessed. Life event stress and emotional stress were evaluated using "Event-Stress-Scale-for-Pregnant-Women" and "Symptom-Checklist-90-R-Scale" (SCL-90-R), respectively. Logistic regression and general linear models were used to evaluate associations between migration status and lead/stress/low selenium exposure. Compared with the local (with Shanghai hukou and length-of-residency ≥ 5 years), new migrants (without Shanghai hukou and length-of-residency < 2 years) had lower social-economic-status (SES), higher lead, life event and emotional stress, and lower selenium levels. After adjusting for SES, new migrants had higher risks of emotional stress (for interpersonal sensitivity of SCL-90-R, OR = 2.10, 95% CI 1.22-3.64) and low selenium [lg(selenium): beta = - 0.08, 95% CI - 0.11, - 0.05], but no significant risks for life event stress and high lead. Compared with the local, migrant pregnant women in big cities may have emotional stress and low selenium independent of SES, and high lead and life event stress dependent on SES.

Placental levels of metals and associated factors in urban and sub-urban areas of Seville (Spain)

Environmental exposure to metals among women, revealed their adverse effects on pregnancy. The fetus is exposed to these toxic elements only via the placenta which are able to accumulate there or cross it, compromising the protective functions of this organ. Numerous studies have shown associations between the prenatal exposition to some metals and an impact on cognitive, motor and intellectual development of the child. Sixty two placental samples were taken at delivery to determine the mineral content (Al, B, Ba, Ca, Cd, Cr, Cu, Fe, K, Li, Mg, Mn, Mo, Na, Ni, Pb, Sr, V, Zn) by ICP-OES. Among these metals, essential ones (B, Ca, Cu, Fe, Mg, Mn, Mo, Na, Zn) can have health beneficial effects at low levels however, in high concentration are potentially toxic. On the other hand, elements such as Al, Cd, Pb, are classified as toxic metals, no matter what its concentration is. The aim of this study is to find the potential relationships between these metals levels, newborn's parameters, pregnancy details and the epidemiologic information obtained using a questionnaire data from the participant pregnant women from Seville (Spain). The main maternal determinant of detectable placenta Cd levels was smoking during pregnancy. Other maternal factors that may affect placenta metal levels were gestational age (Al, B, Ba, and Pb) or dietary supplement (Fe). It has to be stressed that our results have to be interpreted with caution, because of the small study group and the low exposure levels, along with the lack of information on potential sources of exposure to these metals. The use of placenta samples obtained at delivery can be considered strength of this study since the concentration of some metals in placenta can indicate the extent of maternal exposure during gestation.

Determination of lead levels in maternal and umbilical cord blood at birth at the Lagos University Teaching Hospital, Lagos

BACKGROUND

Lead toxicity is a cause of intellectual disability in children and majority of affected children live in developing countries. Its adverse effect on pregnancy outcome has also been documented.

OBJECTIVES

To assess the relationship between maternal blood lead levels and umbilical cord blood lead levels in their corresponding newborn infants; to determine factors associated with high blood lead levels and the pregnancy outcome in participants.

MATERIALS AND METHODS

This was a cross-sectional descriptive study carried out at a tertiary Teaching Hospital, Lagos, Nigeria. Four hundred and forty pregnant women and their respective newborns delivered at the study centre. Blood samples were obtained from the mothers and umbilical cord of the newborns at delivery and analysed by atomic absorption spectrophotometry. Socio-demographic and obstetric data was obtained by questionnaires administered to the mothers. The anthropometric measurements of the babies were taken at birth and clinical data recorded. Main outcome measures were blood lead levels in mother and baby pair, socio-demographic factors, birth weight, gestational age, length, occipito-frontal circumference.

RESULTS

The median maternal and umbilical blood lead level was 64.3μg/dl and 39.2μg/dl respectively. The levels were above 5μg/dl in 75.6% and 66.8% of mothers and umbilical cord respectively. There was a strong positive correlation between the maternal and umbilical cord blood lead levels (rs = 0.80). Use of calcium supplements during pregnancy was significantly associated with a lower maternal blood lead level (p = 0.010) while recent painting and renovation of residential accommodation were associated with a higher umbilical cord blood lead level (p = 0.025). There were no statistically significant associations between the maternal and umbilical cord blood lead levels and the gestational age and anthropometry of the newborns at birth.

CONCLUSIONS

The blood lead levels in newborns of women residing in Lagos, Nigeria are high and administration of antenatal calcium is associated with lower blood lead levels.

Concentrations of mercury (Hg) and selenium (Se) in afterbirth and their relations with various factors

The aim of the study was to evaluate Hg and Se concentrations and Se:Hg molar ratios in the placenta, umbilical cord and fetal membranes, and to examine the relationship between the concentrations of the elements and selected factors. The study material consisted of the placenta, umbilical cord and fetal membranes obtained from 91 healthy women from northwestern and central Poland. In our study mean Hg and Se concentrations in afterbirth were ~ 0.01 mg/kg dry weight (dw) and ≤ 0.5 mg/kg dw, respectively. Correlation analysis showed negative relationships between placenta weight and Se concentration in the placenta and umbilical cord, as well as between placenta length and Se levels in the umbilical cord. We found negative correlations between THg concentration in the placenta and birth weight and between Se concentration in the placenta and umbilical cord and the morphological parameters of the placenta. Furthermore, we noted new types of interactions in specific parts of the afterbirth. In our study, Se:THg molar ratios ranged from 5 to 626; these values indicate protection against Hg toxicity.

Umbilical Serum Copper Status and Neonatal Birth Outcomes: a Prospective Cohort Study

Our study aimed to assess the distribution of copper (Cu) in umbilical cord serum and estimated the association between umbilical serum Cu status and neonatal birth outcomes in a Chinese population. Through the Ma'anShan Birth Cohort Study, 2689 maternal-singleton pairs with detailed birth records and available serum samples were identified. The tertile levels of ln-transformed Cu were used to define low, medium, and high levels for serum Cu. The median for umbilical cord serum Cu was 298.2 μg/L with a range of 123.1-699.6 μg/L in this study population. Our study found a positive association between the concentration of serum Cu in the umbilical cord and the duration of gestation. Compared with medium Cu levels, we found that infants with low Cu levels had a significant higher risk of preterm birth (OR = 5.06, 95% CI 2.74, 9.34) and early-term birth (OR = 1.36, 95% CI 1.10, 1.69) in the crude model. We also found that infants with high Cu levels had a significant higher risk of late- or post-term birth (OR = 1.47, 95% CI 1.11, 1.95). A significant higher risk of preterm, early-term, and late- or post-term birth still remained, even after adjustment for potential confounding factors. Our findings suggested that both Cu deficiency and Cu overload had an adverse effect on neonatal birth outcomes.

Blood mercury concentration, fish consumption and anthropometry in Chinese children: A national study

OBJECTIVE

This study sought to obtain national cross-sectional data for blood mercury levels and risk factors for mercury exposure in Chinese children aged 0 to 6years to provide evidence to support preventive measures for reducing childhood blood mercury levels.

METHODS

A multi-stage, stratified, clustered random sampling survey was conducted May 2013-Mar 2015. Shanghai, Jilin, Shanxi, Guangdong, Qinghai, Yunnan and Hubei, which are located in seven different geographical regions in China, were selected as the study field. A total of 14,202 children aged 0-6years participated in the study. Whole-blood venous samples (3ml) were collected from the subjects for mercury exposure assessment. The DMA-80 was applied for mercury detection, and a health questionnaire gathering information on related confounders was completed by the subjects' parents of the subjects after they received guidance from the investigators. A general linear model was used for the primary descriptive statistical analysis. Odds ratios (ORs) and 95%CIs for the risk factors were estimated using unconditional logistic regression.

RESULTS

A total of 14,202 eligible samples were collected. The mean mercury level was 1.39μg/L. Other results were as follows: median 1.23μg/L, p25 0.86μg/L, p75 1.73μg/L, and GM 1.10μg/L. Of the seven geographical regions, Qinghai, in northwestern China, had a median mercury level of 0.37μg/L, which was significantly lower than the mercury level in Guangdong, in southeastern China (2.01μg/L). The median blood mercury level of children in suburban areas was 1.34μg/L, which was remarkably higher than that of children in rural areas (1.09μg/L). Dichotomous subgroups were generated using the median mercury concentration. Unconditional logistic regression analysis revealed that fish consumption may contribute to increased blood mercury levels (p<0.05). Additionally, we observed significantly positive associations between mercury concentrations and the children's anthropometric characteristics (BMI; p<0.05).

CONCLUSIONS

Blood mercury concentrations among Chinese children aged 0-6years were considered low, and children who consumed more marine fish, freshwater fish and shellfish tended to have higher mercury concentrations. Our study suggests that children's growth is likely affected by the positive effects of mercury, which may have implications concerning the positive effects of fish consumption.

Burden of higher lead exposure in African-Americans starts in utero and persists into childhood

BACKGROUND

Recent public health lead crises in urban areas emphasize the need to better understand exposure to environmental toxicants, particularly in higher risk groups. Although African-American children have the highest prevalence of elevated blood lead levels in the United States, little is known about when this trajectory of disproportionate burden of lead exposure first emerges.

OBJECTIVES

Using tooth-matrix biomarkers that directly measure fetal and early childhood metal levels, the primary goal of this study was to determine if there were racial disparities in lead levels during fetal development and early childhood. Manganese, an essential nutrient that modifies the neurotoxic effects of lead, was also measured.

METHODS

Pregnant women served by the Henry Ford Health System and living in a predefined geographic area in and around Detroit, Michigan, were recruited during the second trimester or later into the Wayne County Health, Environment, Allergy and Asthma Longitudinal Study (WHEALS), a population-based birth cohort. Offspring born between September 2003 and December 2007 were studied in childhood. Child race was parent-reported. Lead and manganese during the second and third trimesters, early postnatal life (birth through age 1year) and early childhood (age 1 through time of tooth shedding, which ranges from 6 to 12years) were measured via high-resolution microspatial mapping of dentin growth rings, a validated biomarker for prenatal and childhood metal exposure.

RESULTS

African-American children (N=71) had 2.2 times higher lead levels in the second and third trimesters (both p<0.001) and 1.9 times higher lead levels postnatally in the first year of life (p=0.003) compared to white children (N=51). Lead levels in African-American children were also higher during childhood, but this effect was only marginally significant (p=0.066) and was attenuated after covariate adjustment. Additionally, we observed that African-American children had lower tooth‑manganese levels during the third trimester (p=0.063) and postnatally (p=0.043), however these differences were attenuated after covariate adjustment.

CONCLUSION

The disproportionate burden of lead exposure is vertically transmitted (i.e., mother-to-child) to African-American children before they are born and persists into early childhood. Our results suggest that testing women for lead during pregnancy (or in pre-conception planning), may be needed to identify the risk to their future offspring, particularly for African-American women.

National and sub-national age-sex specific and cause-specific mortality and disability-adjusted life years (DALYs) attributable to household air pollution from solid cookfuel use (HAP) in Iran, 1990-2013

National and sub-national mortality, years of life lost due to premature mortality (YLLs), years lived with disability (YLDs) and disability-adjusted life years (DALYs) for household air pollution from solid cookfuel use (HAP) in Iran, 1990-2013 were estimated based on the Global Burden of Disease Study 2013 (GBD 2013). The burden of disease attributable to HAP was quantified by the comparative risk assessment method using four inputs: (1) exposure to HAP, (2) the theoretical minimum risk exposure level (TMREL), (3) exposure-response relationships of related causes (4) disease burden of related causes. All across the country, solid fuel use decreased from 5.26% in 1990 to 0.15% in 2013. The drastic reduction of solid fuel use leaded to DALYs attributable to HAP fell by 97.8% (95% uncertainty interval 97.7-98.0%) from 87,433 (51072-144303) in 1990 to 1889 (1016-3247) in 2013. Proportion of YLLs in DALYs from HAP decreased from 95.7% in 1990 to 86.6% in 2013. Contribution of causes in the attributable DALYs was variable during the study period and in 2013 was in the following order: ischemic heart disease for 43.4%, chronic obstructive pulmonary disease for 24.7%, hemorrhagic stroke for 9.7%, lower respiratory infections for 9.3%, ischemic stroke for 7.8%, lung cancer for 3.4% and cataract for 1.8%. Based on the Gini coefficient, the spatial inequality of the disease burden from HAP increased during the study period. The remained burden of disease was relatively scarce and it mainly occurred in seven southern provinces. Further reduction of the disease burden from HAP as well as compensation of the increasing spatial inequality in Iran could be attained through an especial plan for providing cleaner fuels in the southern provinces.

Assessing a New Method for Measuring Fetal Exposure to Mercury: Newborn Bloodspots

BACKGROUND

Measuring mercury in newborn bloodspots to determine fetal exposures is a novel methodology with many advantages. Questions remain, however, about its reliability as an estimate of newborn exposure to mercury.

METHODS

We studied mercury concentrations in paired bloodspots and cord blood from a convenience sample of 48 Minnesota women and infants.

RESULTS

The limit of detection for bloodspots was higher than for cord blood (0.7 and 0.3 μg/L in bloodspots and cord blood, respectively) with the result that mercury was detected in only 38% of newborn bloodspots compared to 62% of cord blood samples. The geometric mean mercury concentration in cord blood was 0.6 μg/L. Mercury concentrations were almost uniformly lower in bloodspots than in cord blood (mean ratio (±SD) = 0.85 ± 0.4), their mean value was significantly less than that for the cord blood (p = 0.02), and the two methods were highly correlated (r = 0.82).

CONCLUSION

These preliminary findings indicate that newborn bloodspot mercury measurements have utility; however, until bloodspot analyses are more sensitive, they are likely to underestimate in utero exposure.

Selenium status during pregnancy and child psychomotor development-Polish Mother and Child Cohort study

BACKGROUND

The studies on the impact of selenium (Se) levels in different pregnancy periods on child psychomotor functions are limited. The aim of this study was to evaluate the impact of prenatal Se on child neurodevelopment.

METHODS

The study population consisted of 410 mother-child pairs from Polish Mother and Child Cohort. Se levels were measured in each trimester of pregnancy, at delivery, and in cord blood by graphite furnace atomic absorption spectrometry. Psychomotor development was assessed in children at the age of 1 and 2 y using the Bayley Scales of Infant and Toddler Development.

RESULTS

Plasma Se levels decreased through pregnancy (from 48.3 ± 10.6 µg/l in the first trimester to 38.4 ± 11.8 µg/l at delivery; P < 0.05). A statistically significant positive association between Se levels in the first trimester of pregnancy and motor development (β = 0.2, P = 0.002) at 1 y of age, and language development (β = 0.2, P = 0.03) at 2 y of age was observed. The positive effect of Se levels on cognitive score at 2 y of age was of borderline significance (β = 0.2, P = 0.05).

CONCLUSION

Prenatal selenium status was associated with child psychomotor abilities within the first years of life. Further epidemiological and preclinical studies are needed to confirm the association and elucidate the underlying mechanisms of these effects.

Cord Blood Methylmercury and Fetal Growth Outcomes in Baltimore Newborns: Potential Confounding and Effect Modification by Omega-3 Fatty Acids, Selenium, and Sex

BACKGROUND

Methylmercury (MeHg) may affect fetal growth; however, prior research often lacked assessment of mercury speciation, confounders, and interactions.

OBJECTIVE

Our objective was to assess the relationship between MeHg and fetal growth as well as the potential for confounding or interaction of this relationship from speciated mercury, fatty acids, selenium, and sex.

METHODS

This cross-sectional study includes 271 singletons born in Baltimore, Maryland, 2004-2005. Umbilical cord blood was analyzed for speciated mercury, serum omega-3 highly unsaturated fatty acids (n-3 HUFAs), and selenium. Multivariable linear regression models controlled for gestational age, birth weight, maternal age, parity, prepregnancy body mass index, smoking, hypertension, diabetes, selenium, n-3 HUFAs, and inorganic mercury (IHg).

RESULTS

Geometric mean cord blood MeHg was 0.94 μg/L (95% CI: 0.84, 1.07). In adjusted models for ponderal index, βln(MeHg) = -0.045 (g/cm(3)) × 100 (95% CI: -0.084, -0.005). There was no evidence of a MeHg × sex interaction with ponderal index. Contrastingly, there was evidence of a MeHg × n-3 HUFAs interaction with birth length [among low n-3 HUFAs, βln(MeHg) = 0.40 cm, 95% CI: -0.02, 0.81; among high n-3 HUFAs, βln(MeHg) = -0.15, 95% CI: -0.54, 0.25; p-interaction = 0.048] and head circumference [among low n-3 HUFAs, βln(MeHg) = 0.01 cm, 95% CI: -0.27, 0.29; among high n-3 HUFAs, βln(MeHg) = -0.37, 95% CI: -0.63, -0.10; p-interaction = 0.042]. The association of MeHg with birth weight and ponderal index was affected by n-3 HUFAs, selenium, and IHg. For birth weight, βln(MeHg) without these variables was -16.8 g (95% CI: -75.0, 41.3) versus -29.7 (95% CI: -93.9, 34.6) with all covariates. Corresponding values for ponderal index were -0.030 (g/cm(3)) × 100 (95% CI: -0.065, 0.005) and -0.045 (95% CI: -0.084, -0005).

CONCLUSION

We observed an association of increased MeHg with decreased ponderal index. There is evidence for interaction between MeHg and n-3 HUFAs; infants with higher MeHg and n-3 HUFAs had lower birth length and head circumference. These results should be verified with additional studies.

Prenatal mercury concentration is associated with changes in DNA methylation at TCEANC2 in newborns

BACKGROUND

Human exposure to the widespread environmental contaminant mercury is a known risk factor for common diseases such as cancer, cardiovascular disease and neurological disorders through poorly characterized mechanisms. Evidence suggests mercury exposure may alter DNA methylation levels, but to date, the effects in early life on a genome-wide scale have not been investigated.

METHODS

A study sample of 141 newborns was recruited in Baltimore, MD, USA and total mercury and methylmercury were measured in cord blood samples. We quantified genome-wide DNA methylation data using CHARM 2.0, an array-based method, and used region-finding analyses to identify concentration-associated differentially methylated regions (DMRs). To test for replication of these identified DMRs in the pilot, or Vanguard, phase of the National Children's Study (NCS), we compared bisulfite-pyrosequenced DNA at candidate regions from 85 whole cord blood samples with matched first trimester maternal mercury concentration measures.

RESULTS

Total mercury concentration was associated with methylation at DMRs inside ANGPT2 and near PRPF18 genes [false discovery rate (FDR) < 0.05], as well as DMRs near FOXD2 and within TCEANC2 (FDR< 0.1) genes. Methylmercury concentration was associated with an overlapping DMR within TCEANC2 (FDR< 0.05). In NCS replication analyses, methylation levels at three of four cytosine-guanine DNA dinucleotides (CpG sites) within the TCEANC2 DMR were associated with total mercury concentration (P < 0.05), and this association was diminished after adjusting for estimated cell proportions.

CONCLUSIONS

Evidence for an association between mercury and DNA methylation at the TCEANC2 region was found, which may represent a mercury-associated shift in cord blood cell composition or a change in methylation within blood cell types. Further confirmatory studies are needed.

Association of selenium and copper with lipids in umbilical cord blood

Altered levels of selenium and copper have been linked with altered cardiovascular disease risk factors including changes in blood triglyceride and cholesterol levels. However, it is unclear whether this can be observed prenatally. This cross-sectional study includes 274 singleton births from 2004 to 2005 in Baltimore, Maryland. We measured umbilical cord serum selenium and copper using inductively coupled plasma mass spectrometry. We evaluated exposure levels vis-à-vis umbilical cord serum triglyceride and total cholesterol concentrations in multivariable regression models adjusted for gestational age, birth weight, maternal age, race, parity, smoking, prepregnancy body mass index, n-3 fatty acids and methyl mercury. The percent difference in triglycerides comparing those in the highest v. lowest quartile of selenium was 22.3% (95% confidence interval (CI): 7.1, 39.7). For copper this was 43.8% (95% CI: 25.9, 64.3). In multivariable models including both copper and selenium as covariates, copper, but not selenium, maintained a statistically significant association with increased triglycerides (percent difference: 40.7%, 95% CI: 22.1, 62.1). There was limited evidence of a relationship of increasing selenium with increasing total cholesterol. Our findings provide evidence that higher serum copper levels are associated with higher serum triglycerides in newborns, but should be confirmed in larger studies.

Elevated serum ferritin and mercury concentrations are associated with hypertension; analysis of the fourth and fifth Korea national health and nutrition examination survey (KNHANES IV-2, 3, 2008-2009 and V-1, 2010)

The impact of simultaneously elevated serum ferritin and mercury concentrations on hypertension in the general population is not known. To determine the association of serum ferritin and mercury concentrations with hypertension, 6213 subjects (3060 men and 3153 women) over 20 years of age from 2008 to 2010 Korea National Health and Nutrition Examination Survey were divided into tertiles according to serum ferritin and mercury concentrations in each gender. Serum ferritin (258.2 vs. 94.8 pmol/L) and mercury concentrations (28.4 vs. 19.9 nmol/L) were higher in men than in women. Serum ferritin (men; P = 0.029, women; P < 0.001) and mercury (men; P < 0.001, women; P = 0.003) concentrations were significantly associated with the prevalence of hypertension. In addition, significant correlation between serum ferritin and mercury concentrations in both men (r = 0.193, P < 0.001) and women (r = 0.145, P < 0.001) were found. Also, the increase of serum ferritin concentrations were more prominent in men (P < 0.001) than in women (P = 0.017) as the serum mercury tertiles increased after proper adjustments. Furthermore, significantly higher odds ratios of hypertension were found in the second (OR = 1.86, 95% CI; 1.05-3.30), and third (OR = 1.84, 95% CI; 1.01-3.36) tertiles of serum ferritin with the top tertile of serum mercury in men. The current study indicate that serum ferritin and mercury concentrations are associated with the prevalence of hypertension and that simultaneously elevated serum ferritin and mercury concentrations are related to the risk for hypertension in men.

Placental transfer and concentrations of cadmium, mercury, lead, and selenium in mothers, newborns, and young children

There is an emerging hypothesis that exposure to cadmium (Cd), mercury (Hg), lead (Pb), and selenium (Se) in utero and early childhood could have long-term health consequences. However, there are sparse data on early life exposures to these elements in US populations, particularly in urban minority samples. This study measured levels of Cd, Hg, Pb, and Se in 50 paired maternal, umbilical cord, and postnatal blood samples from the Boston Birth Cohort (BBC). Maternal exposure to Cd, Hg, Pb, and Se was 100% detectable in red blood cells (RBCs), and there was a high degree of maternal-fetal transfer of Hg, Pb, and Se. In particular, we found that Hg levels in cord RBCs were 1.5 times higher than those found in the mothers. This study also investigated changes in concentrations of Cd, Hg, Pb, and Se during the first few years of life. We found decreased levels of Hg and Se but elevated Pb levels in early childhood. Finally, this study investigated the association between metal burden and preterm birth and low birthweight. We found significantly higher levels of Hg in maternal and cord plasma and RBCs in preterm or low birthweight births, compared with term or normal birthweight births. In conclusion, this study showed that maternal exposure to these elements was widespread in the BBC, and maternal-fetal transfer was a major source of early life exposure to Hg, Pb, and Se. Our results also suggest that RBCs are better than plasma at reflecting the trans-placental transfer of Hg, Pb, and Se from the mother to the fetus. Our study findings remain to be confirmed in larger studies, and the implications for early screening and interventions of preconception and pregnant mothers and newborns warrant further investigation.

Global methylmercury exposure from seafood consumption and risk of developmental neurotoxicity: a systematic review

OBJECTIVE

To examine biomarkers of methylmercury (MeHg) intake in women and infants from seafood-consuming populations globally and characterize the comparative risk of fetal developmental neurotoxicity.

METHODS

A search was conducted of the published literature reporting total mercury (Hg) in hair and blood in women and infants. These biomarkers are validated proxy measures of MeHg, a neurotoxin found primarily in seafood. Average and high-end biomarkers were extracted, stratified by seafood consumption context, and pooled by category. Medians for average and high-end pooled distributions were compared with the reference level established by a joint expert committee of the Food and Agriculture Organization (FAO) and the World Health Organization (WHO).

FINDINGS

Selection criteria were met by 164 studies of women and infants from 43 countries. Pooled average biomarkers suggest an intake of MeHg several times over the FAO/WHO reference in fish-consuming riparians living near small-scale gold mining and well over the reference in consumers of marine mammals in Arctic regions. In coastal regions of south-eastern Asia, the western Pacific and the Mediterranean, average biomarkers approach the reference. Although the two former groups have a higher risk of neurotoxicity than the latter, coastal regions are home to the largest number at risk. High-end biomarkers across all categories indicate MeHg intake is in excess of the reference value.

CONCLUSION

There is a need for policies to reduce Hg exposure among women and infants and for surveillance in high-risk populations, the majority of which live in low-and middle-income countries.

Prenatal lead exposure and relationship with maternal exposure determinants in a public maternity hospital of La Plata, Argentina

Prenatal lead exposure is a health hazard that may cause cognitive development impairments and other adverse effects in children. We conducted a cross sectional study analyzing cord blood lead levels (CBLL) of newborns and their relationship with maternal determinants of lead exposure. Mothers answered a questionnaire about socio-demographic, lifestyle habits and environmental characteristics. We used Mann-Whitney's test to compare CBLL geometrical means (GM) corresponding to the presence or absence of each lead exposure determinant, and Chi square test to study the relationship between CBLL and maternal lead exposure determinants. A total of 159 newborns participated in the study. CBLL GM was 2.1 μg/dL; and 25% of the participants had a measurable CBLL (LOQ=3.3 μg/dl). Although the participants had several determinants of lead exposure, we only found a significant relationship with inside household determinants, such as presence of lead piping (p=0.026), unplastered walls (p=0.046) and peeling paint (p=0.048). Our results show that CBLL GM was similar to that reported in several studies conducted around the world. However, 25% of the participants might have some degree of risk for lead poisoning.

Selenium protects neonates against neurotoxicity from prenatal exposure to manganese

Manganese (Mn) exposure can affect brain development. Whether Selenium (Se) can protect neonates against neurotoxicity from Mn exposure remains unclear. We investigated this issue in 933 mother-newborn pairs in Shanghai, China, from 2008 through 2009. Umbilical cord serum concentrations of Mn and Se were measured and Neonatal Behavioral Neurological Assessment (NBNA) tests were conducted. The scores <37 were defined as the low NBNA. The median concentrations of cord serum Mn and Se were 4.0 µg/L and 63.1 µg/L, respectively. After adjusting for potential confounders, the interaction between Se and Mn was observed. Cord blood Mn levels had different effects on NBNA scores stratified by different cord blood Se levels. With Se Collapse

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MESH Headings

• Analysis of Variance
• Female
• Humans
• Infant, Newborn
• Male
• Manganese/toxicity
• Maternal Exposure/adverse effects
• Neuroprotective Agents/pharmacology
• Pregnancy
• Prenatal Exposure Delayed Effects/prevention & control
• Selenium/pharmacology

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Affiliation(s)

Xin Yang MOE-Shanghai Key Lab of Children’s Environmental Health, Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
YiXiao Bao Department of Pediatrics, Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
HuanHuan Fu MOE-Shanghai Key Lab of Children’s Environmental Health, Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
LuanLuan Li MOE-Shanghai Key Lab of Children’s Environmental Health, Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
TianHong Ren MOE-Shanghai Key Lab of Children’s Environmental Health, Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
XiaoDan Yu MOE-Shanghai Key Lab of Children’s Environmental Health, Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China

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Assessment of exposure to trace metals in a cohort of pregnant women from an urban center by urine analysis in the first and third trimesters of pregnancy

Prenatal exposure to trace metals, whether they are essential, non-essential, or toxic, must be assessed for their potential health effects in the offspring. Herein is reported an approach to this end which involved collection of urine samples during the first and third trimesters of pregnancy from 489 mothers from Sabadell (Catalonia, Spain), a highly industrialized town. These samples were analyzed for cobalt (Co), nickel (Ni), copper (Cu), zinc (Zn), selenium (Se), arsenic (As), molybdenum (Mo), cadmium (Cd), antimonium (Sb), cesium (Cs), thallium (Tl), and lead (Pb). An acid digestion method was developed and validated for inductively coupled plasma quadruple mass spectrometry (Q-ICP-MS) analysis of these 12 metals. The median concentrations of metals ranged from 0.13 to 290 μg/g creatinine, the highest levels were found for Zn and the lowest for Th. The mean concentrations of most metals except As, Ni, Th, and Pb showed statistically significant differences between both trimesters. The concentrations of Mo, Se, Cd, Cs, and Sb were higher in the first than in the third trimester, whereas the opposite was found for Co, Cu, and Zn. The concentrations of all metals in both sampling periods showed statistically significant correlations (p<0.01 for Mo and Cu, p<0.001 for the others). The significant correlations of metal urine concentrations in the first and third trimesters of pregnancy suggest that the observed differences between both periods are related to physiological changes. Accordingly, the measured urine concentrations during either the first or third trimesters can be used as estimates of exposure during pregnancy and can serve as markers for prenatal intake of these metals in the studied cohort.

Mercury concentrations in human placenta, umbilical cord, cord blood and amniotic fluid and their relations with body parameters of newborns

Studies were conducted on samples taken from giving birth women (n = 40) living in Poland, representing three age groups: 19-25, 26-30 and 31-38 years old. Mercury concentrations were measured with CV-AAS in placenta, umbilical cord, cord blood and amniotic fluid. The placentas weight did not exceed the 750 g value and was heavier than 310 g. Mean values of Hg concentrations in blood, placenta and umbilical cord were similar (c.a. 9 μg/g). High levels of mercury were noted in cord blood which in 75% of all observations exceeded (up to 17 μg/L) the safe dose set by US EPA (5.8 μg/L). No statistically significant differences in medium level of Hg in all the studied tissues among age groups of women were observed. Positive correlations between Hg concentrations in placenta and umbilical cord and cord blood were revealed as well as some negative ones between mercury concentrations and pregnancy parameters.

Serum selenium levels of the very low birth weight premature newborn infants with bronchopulmonary dysplasia

BACKGROUND

The selenium (Se) is an essential trace element that has a critical role in synthesis and activity of a number of selenoproteins with protective properties against free radical damage. This study was conducted to detect the serum Se concentration in very low birth weight (VLBW) preterm infants and its association with bronchopulmonary dysplasia (BPD).

MATERIALS AND METHODS

Cord blood Se concentration was determined in 54 neonates with gestation age 30 week or less. Another sample was obtained from these infants at day 28 of birth and serum Se levels were measured by atomic absorption spectrophotometer. All neonates were followed for oxygen dependency at 28 day after birth and 36 week postmenstrual age.

RESULTS

The mean cord blood Se concentration in studied neonates was 64.78 ± 20.73 μgL(-1). Serum Se concentration was 60.33 ± 26.62 μgL(-1) at age 28-day. No significant correlation was observed for serum Se concentration at birth and at one month after birth (r = -0.04, p = 0.72). BPD was diagnosed in 25 neonates (46%). The mean serum Se concentration at one month was 57.16 ± 29.68 μgL(-1) in patients with BPD (25 cases) and 63.27 ± 23.6 μgL(-1) in 29 patients without BPD (p = 0.40).

CONCLUSION

In our study, serum Se concentration at 28 day of birth was lower than cord blood levels in preterm neonates, but we have not found significant difference among patients who had BPD or not with respect to serum Se concentrations at this age.

Health effects in the Flemish population in relation to low levels of mercury exposure: from organ to transcriptome level

Due to possible health risks, quantification of mercury accumulation in humans was included in the Flemish biomonitoring programmes FLEHS I (2002-2006) and FLEHS II (2007-2011). The general objective of FLEHS I was to assess regional exposure levels in order to link possible differences in these internal exposure levels to different types of local environmental pressure. Therefore, Hg and MMHg (methylmercury) were only measured in pooled blood samples per region and per age class. In FLEHS II, mercury concentrations were measured in hair of each participant. About 200 adolescents and 250 mothers (reference group) and two times 200 adolescents (2 hotspots) were screened. The main objectives of the FLEHS II study were: (1) to determine reference levels of mercury in hair for Flanders; (2) to assess relations between mercury exposure and possible sources like fish consumption; (3) to assess dose-effect relations between mercury exposure and health effect markers. The results showed that mercury concentrations in the Flemish population were rather low compared to other studies. Mercury levels in the Flemish populations were strongly related to the age of the participants and consumption of fish. Significant negative associations were observed between mercury in hair and asthma, having received breast feeding as a newborn, age at menarche in girls, allergy for animals and free testosterone levels. Significant correlations were also observed between mercury in hair and genes JAK2, ARID4A, Hist1HA4L (boys) and HLAdrb5, PIAS2, MANN1B1, GIT and ABCA1 (girls).

Different levels of prenatal zinc and selenium had different effects on neonatal neurobehavioral development

Either deficient or excessive of essential nutrients had adverse effects. Effects of different levels of prenatal zinc (Zn) and selenium (Se) on fetal neurobehavioral development remain unclear. To determine the effects of different cord serum levels of Zn and Se on neurobehavioral development in neonates and to explore possible threshold level of Zn and Se based on fetal neurodevelopment, we conducted this epidemiological research. In the multi-center study, we investigated these questions in 927 mother-newborn pairs in Shanghai, China, from 2008 through 2009. Umbilical cord serum concentrations of Zn and Se were measured and Neonatal Behavioral Neurological Assessment (NBNA) tests were conducted. The median cord serum Zn and Se concentrations were 794.3 μg/L and 63.1 μg/L, respectively. A nonlinear relationship was observed between cord serum Zn and NBNA after adjusting for potential confounders. NBNA score decreased with increasing Zn levels after 794.3 μg/L (adjusted β=-3.0, 95% CI: -3.6 to -2.4, p<0.001). Additionally, an invert U-shape with a threshold Se of 100 μg/L was observed between cord serum Se and NBNA. The adjusted regression coefficient was 4.4 (95% CI: 3.6-5.2, p<0.001) for Se<100 μg/L while -3.6 (95% CI: -6.1 to -1.1, p<0.01) for Se≥100 μg/L. Of the 927 infants, 50% had a high level Zn (≥794.3 μg/L) and 8.6% had a high level Se (≥100 μg/L). High levels of both Zn and Se mainly had adverse effects on behavior and passive tone (p<0.001). Taken together, our study suggested that a threshold of cord blood Zn and Se was existed for fetal neurodevelopment and the prevalence of excessive Zn was high. Thus, the supplementation of Zn during pregnancy should be considered with caution in Shanghai, China.

DNA methylation shows genome-wide association of NFIX, RAPGEF2 and MSRB3 with gestational age at birth

BACKGROUND

Gestational age at birth strongly predicts neonatal, adolescent and adult morbidity and mortality through mostly unknown mechanisms. Identification of specific genes that are undergoing regulatory change prior to birth, such as through changes in DNA methylation, would increase our understanding of developmental changes occurring during the third trimester and consequences of pre-term birth (PTB).

METHODS

We performed a genome-wide analysis of DNA methylation (using microarrays, specifically CHARM 2.0) in 141 newborns collected in Baltimore, MD, using novel statistical methodology to identify genomic regions associated with gestational age at birth. Bisulphite pyrosequencing was used to validate significant differentially methylated regions (DMRs), and real-time PCR was performed to assess functional significance of differential methylation in a subset of newborns.

RESULTS

We identified three DMRs at genome-wide significance levels adjacent to the NFIX, RAPGEF2 and MSRB3 genes. All three regions were validated by pyrosequencing, and RAGPEF2 also showed an inverse correlation between DNA methylation levels and gene expression levels. Although the three DMRs appear very dynamic with gestational age in our newborn sample, adult DNA methylation levels at these regions are stable and of equal or greater magnitude than the oldest neonate, directionally consistent with the gestational age results.

CONCLUSIONS

We have identified three differentially methylated regions associated with gestational age at birth. All three nearby genes play important roles in the development of several organs, including skeletal muscle, brain and haematopoietic system. Therefore, they may provide initial insight into the basis of PTB's negative health outcomes. The genome-wide custom DNA methylation array technology and novel statistical methods employed in this study could constitute a model for epidemiologic studies of epigenetic variation.

Defining reference values of trace elements in the tear film: diagnostic methods and possible applications

The study has been performed on tears of apparently healthy subjects who live and work in urban and rural areas, respectively. After the collection the following elements were investigated: chromium (Cr); arsenic (As); copper (Cu); zinc (Zn); selenium (Se); rubidium (Rb); barium (Ba); lead (Pb) and cobalt (Co). Significantly higher values of As were found in subjects living and working in rural areas as compared to those found in urban area residents (0.290 vs. 0.025; p<0.001). Conversely, Ba and Pb were significantly lower in rural area residents (1.10 vs. 2.50, p=0.027 and 1.70 vs. 1.10, p=0.057, respectively). Our data show that trace elements analysis in tears is possible; further studies could define if it could be a reliable biomarker in persons exposed to high concentration of trace elements due to working or environmental reasons.

Prioritization of biomarker targets in human umbilical cord blood: identification of proteins in infant blood serving as validated biomarkers in adults

BACKGROUND

Early diagnosis represents one of the best lines of defense in the fight against a wide array of human diseases. Umbilical cord blood (UCB) is one of the first easily available diagnostic biofluids and can inform about the health status of newborns. However, compared with adult blood, its diagnostic potential remains largely untapped.

OBJECTIVES

Our goal was to accelerate biomarker research on UCB by exploring its detectable protein content and providing a priority list of potential biomarkers based on known proteins involved in disease pathways.

METHODS

We explored cord blood serum proteins by profiling a UCB pool of 12 neonates with different backgrounds using a combination of isoelectric focusing and liquid chromatography coupled with matrix-assisted laser desorption/ionization tandem mass spectrometry (MALDI-MS/MS) and by comparing results with information contained in metabolic and disease databases available for adult blood.

RESULTS

A total of 1,210 UCB proteins were identified with a protein-level false discovery rate of ~ 5% as estimated by naïve target-decoy and MAYU approaches, signifying a 6-fold increase in the number of UCB proteins described to date. Identified proteins correspond to 138 different metabolic and disease pathways and provide a platform of mechanistically linked biomarker candidates for tracking disruptions in cellular processes. Moreover, among the identified proteins, 38 were found to be approved biomarkers for adult blood.

CONCLUSIONS

The results of this study advance current knowledge of the human cord blood serum proteome. They showcase the potential of UCB as a diagnostic medium for assessing infant health by detection and identification of candidate biomarkers for known disease pathways using a global, nontargeted approach. These biomarkers may inform about mechanisms of exposure-disease relationships. Furthermore, biomarkers approved by the U.S. Food and Drug Administration for screening in adult blood were detected in UCB and represent high-priority targets for immediate validation.