Serum reference levels of selenium, zinc and copper in healthy pregnant women at a prenatal screening program in southeastern Mediterranean region of Turkey

Metalloestrogens exposure and risk of gestational diabetes mellitus: Evidence emerging from the systematic review and meta-analysis

BACKGROUND

Metalloestrogens are metals and metalloid elements with estrogenic activity found everywhere. Their impact on human health is becoming more apparent as human activities increase.

OBJECTIVE

Our aim is to conduct a comprehensive systematic review and meta-analysis of observational studies exploring the correlation between metalloestrogens (specifically As, Sb, Cr, Cd, Cu, Se, Hg) and Gestational Diabetes Mellitus (GDM).

METHODS

PubMed, Web of Science, and Embase were searched to examine the link between metalloestrogens (As, Sb, Cr, Cd, Cu, Se, and Hg) and GDM until December 2023. Risk estimates were derived using random effects models. Subgroup analyses were conducted based on study countries, exposure sample, exposure assessment method, and detection methods. Sensitivity analyses and adjustments for publication bias were carried out to assess the strength of the findings.

RESULTS

Out of the 389 articles identified initially, 350 met our criteria and 33 were included in the meta-analysis, involving 141,175 subjects (9450 cases, 131,725 controls). Arsenic, antimony, and copper exposure exhibited a potential increase in GDM risk to some extent (As: OR = 1.28, 95 % CI [1.08, 1.52]; Sb: OR = 1.73, 95 % CI [1.13, 2.65]; Cu: OR = 1.29, 95 % CI [1.02, 1.63]), although there is a high degree of heterogeneity (As: Q = 52.93, p < 0.05, I2 = 64.1 %; Sb: Q = 31.40, p < 0.05, I2 = 80.9 %; Cu: Q = 21.14, p < 0.05, I2 = 71.6 %). Conversely, selenium, cadmium, chromium, and mercury exposure did not exhibit any association with the risk of GDM in our study.

DISCUSSION

Our research indicates that the existence of harmful metalloestrogens in the surroundings has a notable effect on the likelihood of GDM. Hence, we stress the significance of environmental elements in the development of GDM and the pressing need for relevant policies and measures.

Variations in Blood Copper and Possible Mechanisms During Pregnancy

Copper (Cu), an essential trace element, is crucial for both the mother and fetus. Currently, an increasing number of studies have focused on blood copper levels during pregnancy. Studies have found that blood copper levels in pregnant women are higher than those in reproductive-age women, but the trend, mainly in the 2nd and 3rd trimester, is still controversial. Most studies showed that blood copper levels gradually increased during pregnancy, while some studies found that blood copper levels remained stable or even decreased in the 3rd trimester. The possible mechanisms of variations in blood copper during pregnancy include the influence of estrogen (hepatic uptake and excretion, ceruloplasmin synthesis, maternal-fetal transport, etc.), the interaction of other trace elements (Fe, Zn, etc.) and other factors. Among them, maternal-fetal copper transport caused by elevated estrogen may be the main reason for the inconsistencies observed in the 2nd and 3rd trimester during pregnancy. However, there are some mechanisms require further investigation. In the future, the trend and mechanisms of blood copper during pregnancy should be explored more deeply to help doctors better monitor copper status and detect copper abnormalities in time.

High Levels of 25-OH-Vitamin D and Copper in Pregnant Women with Abnormal Glucose Challenge Test

Several hormones and elements are involved in the homeostasis of glucose metabolism during pregnancy. This present study determined the differences among the factors involved in glucose regulation for pregnant women with and without an abnormal glucose challenge test (GCT), but without gestational diabetes mellitus, during the second trimester of gestation and the postpartum period. One hundred and six pregnant women who had received routine prenatal and postpartum examinations at our hospital were recruited. Sugar-related tests and the levels of pregnancy-associated hormones and 25-OH-vitamin D were performed using a clinical autoanalyzer; six elements were assessed using graphite furnace atomic absorption spectrometry or inductively coupled plasma mass spectrometry. The women in the abnormal GCT group (n = 27) featured significantly higher levels of 25-OH-vitamin D (p = 0.006) and copper (p < 0.001) than those in the normal GCT group (n = 79). After adjusting for possible pregnancy factors, abnormal GCT remained the significant contributing factor for the elevated levels of 25-OH-vitamin D and copper during gestation (p = 0.046 and 0.002, respectively). Furthermore, significant positive correlations existed between 25-OH-vitamin D and glucose after a 50-g GCT (p = 0.001), 25-OH-vitamin D and HbA_1C (p = 0.004), serum copper and glucose after a 50-g GCT (p = 0.003), and serum copper and HbA_1C (p < 0.001). We conclude that blood 25-OH-vitamin D and copper are strongly correlated with glucose levels during gestation; these two factors are potential clinical predictors for maternal impaired glucose tolerance and, indirectly, for reducing perinatal risks and neonatal complications.

Determination of 14 trace elements in blood, serum and urine after environmental disaster in the Doce River basin: Relationship between mining waste and metal concentration in the population

BACKGROUND

Exposure to chemical substances after an environmental disaster can cause both toxic effects and changes in the health status of people who live in or have proximity to environments of this nature, so that the concern with populations is growing.

METHODS

In this cross-sectional study, blood, serum and urine samples were collected from 100 volunteers from Santo Antônio do Rio Doce, eight from Ilha das Pimentas and 50 from the control group; and analyzed by inductively coupled plasma mass spectrometry for biomonitoring of Al, As, Ba, Cd, Co, Cu, Cr, Fe, Hg, Mn, Ni, Se, Pb, Zn. In addition, a comprehensive questionnaire was applied to collect demographic and socioeconomic information, as well as lifestyle.

RESULTS

The concentrations of As, Al, Cd, Ni and Mn were above the reference value in some biological matrices, with more pronounced exposure in Ilha das Pimentas. The concentrations of As, Cd, Cu, Co, Pb and Zn showed statistical differences regarding gender in the different biological matrices. The trace elements in the blood, serum and urine showed significant correlations when considering age and habits such as the consumption of cigarettes, alcoholic beverages and fish. The main correlations were observed between Co, Cr, Mn, Ni and Pb in the blood and cigarette consumption.

CONCLUSION

This is the first study in these regions after the environmental disaster and confirmation of the diagnosis and health care of the participants should be promoted for clinical investigation and the eventual need for treatment. Human biomonitoring demonstrated high concentrations of some toxic elements, with more accentuated exposure in Ilha das Pimentas.

Relationship of Circulating Copper Level with Gestational Diabetes Mellitus: a Meta-Analysis and Systemic Review

BACKGROUND AND PURPOSE

Gestational diabetes mellitus (GDM) represents the frequently occurring medical disorder beginning in the process of pregnancy. No consensus has been reached about the relationship of circulating copper content with the risk of GDM. Therefore, the present work carried out a meta-analysis for summarizing epidemiological research regarding the copper level with the GDM risk. Furthermore, studies using categories of copper concentration as exposure were combined by dose-response meta-analysis.

METHODS

Related studies were retrieved against the PubMed, Web of Science, and Scopus databases from inception till August 2020. The overall effects were expressed as standard mean difference (SMD). A dose-response meta-analysis was conducted to assess whether the higher copper concentration was associated with higher risks of GDM. Stata 16.0 and Review Manager 5.3 were utilized for data analysis.

RESULTS

A total of fourteen articles involving were retrieved for meta-analysis; in the meantime, 2670 pregnant subjects including 910 GDM cases were enrolled for quantitative analysis. Based on the integrated findings, GDM cases showed increased circulating copper contents relative to those in normal pregnant subjects (SMD = 0.65, 95% CI 0.19 to 1.11; P = 0.005). There was no obvious evidence of publication bias among the studies enrolled. Subgroup analysis showed that such trend was consistent in the third trimester (SMD = 1.21, 95% CI 0.35 to 2.08; P = 0.006) but not second trimester. Meanwhile, circulating copper concentration was significantly higher in women with GDM than those without GDM within the Asian population but not within the Caucasian population (Asia: SMD = 0.73; 95% CI 0.12 to 1.34, P = 0.02; Europe: SMD = 0.49; 95% CI: - 0.23 to 1.20, P = 0.18). Further, serum copper analysis together with subgroup analysis was conducted, and the same result was obtained. For dose-response analysis, the linear associations between circulating copper and risks of GDM were revealed, that higher circulating copper concentration during pregnancy is closely associated with GDM.

CONCLUSION

According to existing evidence, the serum copper concentration increased among GDM cases compared with subjects with normality in glucose tolerance pregnant subject, in particular among the Asians and during the third trimester. The finding from dose-response analysis suggested that increased copper level is associated with an increased risk of GDM. Nonetheless, more specially designed prospective articles should be carried out for understanding the dynamic relationship of copper concentration with the GDM risk.

Nutritional Status of Selenium and Its Association with Diet and Indoor Air Pollution among Pregnant Women in a Rural Area of Northern China

The nutritional status of selenium (Se) in pregnant women in rural areas of northern China and its association with diet and indoor air pollution are rarely reported. We recruited 273 pregnant women in early or middle term in Shanxi and Hebei province and detected their fasting blood selenium. Demographic characteristics, food habits, and indoor air pollution exposure were collected with a questionnaire. Multivariate logistic regression models were used to estimate the adjusted odds ratios (AORs) and their 95% confidence intervals for the factors and relatively low blood levels of Se (below the lower quartile). The median (interquartile range [IQR]) blood concentration of Se was 117.35 (103.90, 129.23) μg/L. The rate of Se deficiency was 4.8%, and the rate of overnutrition was 23.8%. The AORs for the risk for relatively low blood levels of Se were 2.26 (1.15, 4.44) for consuming less beef and pork/mutton; 0.39 (0.19, 0.80) for a lower frequency of vinegar consumption; and 1.41 (0.76, 2.60) and 1.18 (0.59, 2.36) for passive smoking and indoor coal pollution, respectively. In conclusion, the nutritional status of Se in pregnant women in a rural area of northern China was acceptable; diet was the main determinant; no conclusive association was found between indoor air pollution and Se nutritional status.

Associations between blood heavy metal(loid)s and serum heme oxygenase-1 in pregnant women: Do their distribution patterns matter?

The relationship between heavy metal(loid)s exposure and oxidative stress damage is a matter of research interest. Our study aimed to investigate the distribution patterns of the nine heavy metal(loid)s in blood of pregnant women, including four toxic heavy metal(loid)s [arsenic (As), cadmium (Cd), lead (Pb) and mercury (Hg)] and five typical heavy metal(loid)s [manganese (Mn), cobalt (Co), copper (Cu), zinc (Zn), and selenium (Se)] in blood. Blood samples of 348 women were collected and their concentrations in the serum (sr) and blood cells (bc) were measured, as well as serum heme oxygenase-1 (HO-1) (an oxidative stress marker). Total blood (tb) concentrations of these metal(loid)s and serum-to-blood cell concentration ratios (sr/bc) were further calculated. We found Cu mainly accumulated in the serum compared to the blood cells with Cu^sr/bc = 2.30, whereas Co, Se, and As evenly distributed between these two fractions. Other metal(loid)s mainly concentrated in the blood cells. Co^sr, Cu^sr, Cu^bc, Mn^bc, Zn^bc, Cd^bc, Co^tb, Cu^tb, Mn^tb, Zn^tb, Cd^tb, and Cu^sr/bc were negatively associated with serum HO-1, whereas As^sr, As^bc, As^tb, Zn^sr/bc, Cd^sr/bc, and Hg^sr/bc were positively, indicating of their potential toxicity. We concluded that the distribution patterns of blood heavy metal(loid)s, in particular for Cd, Hg and Zn, which either increased in serum or decreased in blood cells, might be associated with elevated serum oxidative stress, should be considered in environmental health assessments.

The Relationship Between Heavy Metal Exposure, Trace Element Level, and Monocyte to HDL Cholesterol Ratio with Gestational Diabetes Mellitus

The objective of this study is to assess the levels of heavy metals (cadmium, lead, antimony, mercury, and arsenic), which are also called endocrine-disrupting chemicals, and trace elements (chromium-III, chromium-VI, zinc, copper, and selenium) vs. monocyte to HDL ratio among pregnant women with gestational diabetes mellitus (GDM). A total of 112 pregnant women (60 with GDM and 52 healthy women) were included in this case-control study. Analysis of heavy metals and trace elements were performed in inductively coupled plasma mass spectrometer. Heavy metals (cadmium, lead, antimony, mercury, and arsenic), trace elements (chromium-III, chromium-VI, zinc, copper, and selenium), and metabolic parameters were assessed in both groups. It was determined that the levels of cadmium, lead, antimony, and copper were higher (p < 0.05) and levels of chromium-III, zinc, and selenium were lower (p < 0.05) among the GDM group compared to the control group, whereas there was a statistically insignificant difference between the two groups, regarding the levels of copper, mercury, and arsenic (p > 0.05). Moreover, the monocyte to HDL ratio was higher in the GDM group (p < 0.05), and the insulin resistance was significantly higher as well (p < 0.05). The results of our study demonstrated that environmental factors could be effective in the etiology of GDM. Toxic heavy metals, through inducing Cu, OS, and chronic inflammation, and other trace elements, either directly by impacting insulin secretion or through weakening the body's antioxidant defense system, could play a role in the occurrence of GDM.

Selenium, Zinc, and Manganese Status in Pregnant Women and Its Relation to Maternal and Child Complications

Micronutrients, as essential components of prenatal care, are important to reduce the risk for maternal and child morbidity and mortality by lowering pregnancy-related complications. The present study aimed to investigate the status of the trace elements, i.e., selenium, zinc, and manganese in pregnant and non-pregnant women from a developing country and to evaluate its relationship with maternal and child complications. Selenium, zinc, and manganese concentrations were measured in the blood serum of 80 pregnant women and compared with 40 non-pregnant healthy controls. The quantitative analyses of trace elements were performed by using the inductively coupled plasma–optical emission spectrometry (ICP-OES) method. The information about the dietary habits of the study participants was recorded by using a food frequency questionnaire. The results showed significant lower selenium and zinc levels in pregnant women as compared to the controls (2.26 ± 1.09 vs. 2.76 ± 1.15 µmol/L, p = 0.031; 21.86 ± 7.21 vs. 29.54 ± 7.62 µmol/L, p < 0.001) respectively, with no difference in manganese concentrations (1.40 ± 0.09 vs.1.38 ± 0.09 log₁₀ nmol/L, p = 0.365). Regarding maternal and child complications, higher manganese levels were associated with an increased odds ratio for maternal complications (OR = 3.175, CI (95%) 1.631−6.181; p = 0.038). Consumption of dairy products was associated with lower selenium and manganese values. Pregnant women showed a lower serum selenium and zinc status, and in addition elevated serum manganese concentrations, which might be associated with a higher risk for maternal pregnancy/birth complications, although more studies are necessary to evaluate this association.

Evaluation of Essential and Toxic Elements in Amniotic Fluid and Maternal Serum at Birth

The objective of this study was to determine the concentration and the reference ranges of essential and toxic elements in amniotic fluid (AF) and maternal serum (MS) at birth. This study was conducted among 175 healthy pregnant Caucasian European women aged 18-42. AF and maternal blood samples were collected during delivery. An inductively coupled plasma mass spectrometry (ICP-MS) technique was used to determine the levels of Mg, Co, Cu, Zn, Sr, Cd, Ba, Pb, U, Ca, Cr, Al, Mn, V, Fe, As, Se and Sb in AF and MS. The range of reference values was calculated for all analyzed elements in the serum and AF. The mean concentrations of elements, except Pb, were generally higher in MS than in AF. Multiple regression analysis showed that the maternal/newborn body mass (MBM/NBM) ratio was a strong negative predictor (among maternal age and gravidity) of Mg concentration in amniotic fluid. In the serum, MBN/NBM ratio was a strong positive predictor of Cu concentration. Moreover, regression analysis showed that maternal age was an independent positive predictor of the Se level in maternal serum. The reference value ranges of 18 essential and toxic elements were established in AF and MS among a population of healthy pregnant Polish women at delivery. The level of Mg, Co, Cu, Ca and Se in AF and MS can be determined by maternal age and MBM/NBM ratio. These results can be useful in counseling individuals with pregnancies affected by exposure to one of the parameters under investigation.

Trace element profiles in pregnant women's sera and umbilical cord sera and influencing factors: Repeated measurements

In utero exposure to toxic heavy metals and deficient or excessive essential trace elements during pregnancy may have adverse effects on pregnant women and their offsprings, which are of great concern. The objective of the present study was to characterize serum concentrations of multiple trace elements at multiple time points during pregnancy in Chinese women. Three thousand four hundred and sixteen pregnant women in total were included from MABC (Ma'anshan Birth Cohort) study. Fasting sera in the morning and questionnaires were obtained at three separate follow-up visits. Nineteen trace elements from serum samples were analyzed, including aluminum (Al), vanadium (V), chromium (Cr), manganese (Mn), iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), zinc (Zn), arsenic (As), selenium (Se), cadmium (Cd), barium (Ba), thallium (Tl), lead (Pb), calcium (Ca), magnesium (Mg), mercury (Hg) and molybdenum (Mo). The total detection rates for most elements were 100% rather than Ni (99.98%), As (99.97%), Cd (99.6%), Ba (99.9%), Pb (99.8%), Hg (99.8%). The concentration distributions of 19 elements varied vastly. Median concentrations for all trace elements ranged from 38.5 ng/L to 102.9 mg/L. The moderate interclass correlation coefficients (ICCs) were observed for Co, Cu, Se and Hg, ranging from 0.40 to 0.62; the lower ICCs, ranging from 0.13 to 0.32 were for Fe, Zn, Cd, Ba, Tl, Mg and Mo. The intraclass correlation effects were not observed for the remaining elements, such as Al, V, Cr, Mn, Ni, As and Pb. The concentrations of each element between three time points were significantly different; significant differences were also found between any two time points except for Ni, Cd and Mo. Many factors could affect the levels of trace elements, and a very important factor of them was season. Consequently, a single measurement of elements in sera seems not enough to describe exposure levels throughout pregnancy; additionally, season affected exposure levels of trace elements with moderate ICCs showed certain regularity. Future analyses should take sampling seasons into consideration carefully.

Maternal copper status and neuropsychological development in infants and preschool children

INTRODUCTION

Copper (Cu) is an essential element involved in biological processes; however, excessive Cu could be harmful because of its reactive nature. Very few studies have evaluated its potential neurotoxic effects. We aimed to evaluate the association between maternal Cu levels and children's neuropsychological development.

METHODS

Study subjects were mother-child pairs from the Spanish INMA (i.e. Childhood and Environment) Project. Cu was measured by inductively coupled plasma mass spectrometry in serum samples taken at the first trimester of pregnancy (2003-2005). Neuropsychological development was assessed using the Bayley Scales of Infant Development (BSID) at 12 months (n = 651) and the McCarthy Scales of Children's Abilities (MSCA) at 5 years of age (n = 490). Covariates were obtained by questionnaires during pregnancy and childhood. Multivariate linear and non-linear models were built in order to study the association between maternal Cu and child neuropsychological development.

RESULTS

The mean ± standard deviation of maternal Cu concentrations was 1606 ± 272 μg/L. In the multivariate analysis, a negative linear association was found between maternal Cu concentrations and both the BSID mental scale (beta = -0.051; 95% confidence intervals [CI]: -0.102, -0.001) and the MSCA verbal scale (beta = -0.044; 95%CI:-0.094, 0.006). Boys obtained poorer scores than girls, with increasing Cu at 12 months (interaction p-value = 0.040 for the mental scale and 0.074 for the psychomotor scale). This effect modification disappeared at 5 years of age. The association between Cu and the MSCA scores (verbal, perceptive performance, global memory and motor, general cognitive, and executive function scales) was negative for those children with lowest maternal iron concentrations (<938μg/L).

CONCLUSION

The Cu concentrations observed in our study were within the reference range established for healthy pregnant women in previous studies. The results of this study contribute to the body of scientific knowledge with important information on the possible neurotoxic capability of Cu during pregnancy.

Association between plasma concentration of copper and gestational diabetes mellitus

BACKGROUND & AIMS

Emerging findings have raised concerns about significant associations between excessive copper (Cu) and abnormal glucose metabolism. Nevertheless, related researches on the relationship of Cu concentration and gestational diabetes mellitus (GDM) are limited. The objective of this study was to determine whether plasma Cu concentration is associated with GDM.

METHODS

A case-control study of 248 cases of GDM and 248 age-, parity- and gestational age-matched controls was conducted in Wuhan, China between August 2012 and April 2015. Fasting blood samples of participants were collected at the time of GDM screening (≥24 weeks of gestation). Plasma Cu concentrations were detected by inductively coupled plasma mass spectrometry. The strength of the association of plasma Cu with GDM odds was evaluated by odds ratios (ORs) with 95% confidence intervals (CIs) from conditional logistic regression. Partial Spearman or Pearson correlation coefficients were calculated to estimate the interrelationship between plasma Cu and the risk factors of GDM.

RESULTS

Plasma Cu concentrations in the GDM group (mean ± SD: 1960.24 ± 391.98 μg/L) were higher than in the control group (mean ± SD: 1842.43 ± 387.09 μg/L) (P = 0.001). After adjustment for possible confounders, the ORs (95% CIs) of GDM across increasing quartiles of plasma Cu levels were 1.00 (referent), 1.79 (0.90-3.55), 2.72 (1.35-5.48) and 2.91 (1.48-5.75), respectively; the OR (95% CI) of GDM was 1.33 (1.06-1.67) for each standard deviation increment of plasma Cu. Moreover, Cu concentrations were positively associated with fasting plasma glucose, 1-h post-glucose load and 2-h post-glucose load (all P < 0.05).

CONCLUSIONS

The present study indicated a significantly increased odds of GDM in association with higher concentrations of plasma Cu. Prospective cohort studies in other populations are needed to confirm our findings.

Association of maternal serum copper during early pregnancy with the risk of spontaneous preterm birth: A nested case-control study in China

BACKGROUND

The effect of maternal copper (Cu) level on the risk of spontaneous preterm birth (SPB) remains debate. Therefore, we conducted a prospective nested case-control study in Shanxi Province to investigate the relationship between maternal serum Cu concentration and SPB risk, as well as the potential mediation effect of lipid metabolism.

METHOD

From an overall cohort of 4229 women, 147 women affected by SPB at 20-36 gestational weeks (cases) and 381 women who delivered at ≥37 gestational weeks (controls) were included in our nested case-control study. Maternal blood samples were collected during 4-22 gestational weeks, and the concentrations of Cu, total cholesterol (TC), and triglycerides (TG) were measured. Information on maternal social demographic characteristics were collected using questionnaires. Unconditional logistic regression models were used to estimate the associations of Cu, TC or TG levels with SPB risk. Linear regressions were used to assess the relationships between concentrations of Cu and TC or TG.

RESULTS

Serum Cu concentrations in the case group (median: 184 μg/dL) were significantly higher than those in the control group (median: 166 μg/dL, p < 0.0001). Compared to the lowest serum Cu levels, the odds ratios associated with SPB increased to 2.02 (95% confidence interval [CI]: 1.07, 3.82), 3.10 (1.54, 6.22) and 4.18 (2.11, 8.27) in the second, third and fourth quartile respectively, after adjusting for sampling time, maternal age, pre-pregnancy BMI, education, occupation, parity, spontaneous abortion history, folic acid use, medication use, pre-pregnancy passive smoking status, child gender and fasting status. Plasma concentrations of TC and TG were positively associated with SPB risk in a dose-dependent manner. However, when stratified by sampling time, the above-mentioned relationships were significant in the first trimester but not in the second. In addition, plasma concentrations of TC and TG were positively correlated with serum Cu concentrations.

CONCLUSIONS

High maternal Cu level in the first trimester may increase the risk of SPB, by potentially increasing plasma concentrations of TC and TG.

Prenatal Exposure to Aluminum and Status of Selected Essential Trace Elements in Rural South African Women at Delivery

This study sought to evaluate the in utero exposure to aluminum and status of selected trace elements in South African women at delivery since aluminum is known to be toxic in all developmental stages even at low concentrations. Serum aluminum was negatively correlated with aluminum in urine, both uncorrected and corrected for creatinine, which suggests the retention of aluminum in body stores. Serum copper and zinc levels were found to be high in this study population. Serum copper levels were negatively correlated with aluminum in serum (β = -0.095; p = 0.05). There was a marginal negative correlation between aluminum levels in serum and manganese levels in whole blood (β = -0.087; p = 0.08). Copper levels in maternal serum were negatively correlated with birth weight and the length of neonates. There were a number of positive correlations between maternal characteristics and birth outcomes. Mothers who consumed root vegetables frequently appeared to be protected from aluminum retention and increased body burden since their serum aluminum levels were found to be significantly lower. The findings of the current study can be used as a baseline for further research on aluminum exposure and its associated interactions and outcomes in vulnerable populations.

The treatment with selenium increases placental parasitismin pregnant Wistar rats infected with the Y strain of Trypanosoma cruzi

Selenium (Se) is an essential micronutrient in the diet of mammals and has an important role in the immune function. Selenium is a key element in selenoproteins involved in the in the maintenance of the antioxidant defense. Diet with selenium is beneficial for the treatment of diseases correlated with high levels of oxidative stress, also observed in the Chagas disease. Chagas disease is a neglected disease caused by the protozoan Trypanosoma cruzi and several research groups are focused on the illness treatment. Immunomodulation of the infection using microelements is an important tool to avoid deleterious effects of the Chagas disease. Therefore, our objective was to evaluate the effects of selenium supplementation on pregnant Wistar rats infected with T. cruzi. Selenium treatment stimulated the weight and length of fetuses and placentas allied to the decrease of blood parasitemia. However, selenium demonstrated a low influence on T cells, diminishing the B cell population (CD45RA⁺). Moreover, the production of pro-inflammatory cytokines was downregulated under selenium administration. Low pro-inflammatory cytokines levels probably are related to the increase in the number of amastigote nests in infected and treated animals. Thus, selenium supplementation during pregnancy could impair the local placental immune response. Further studies are necessary to assess the interaction between selenium and the acute Chagas' disease during pregnancy, which will base future supplementation strategies.

Determination of Trace Metal Levels in the General Population of Korea

The purpose of this study was to determine the levels of trace metals in the blood of the general Korean population. A total of 258 healthy individuals, according to their regular medical check-ups, (119 males and 139 females, age ranging from 12 to 78 years old) were enrolled from December 2014 to December 2016. Levels of 10 trace elements were determined using inductively coupled plasma mass spectrometry (ICP-MS). The geometric mean (GM) levels for lead, arsenic, cesium, mercury, aluminum, cadmium, copper, manganese, selenium, and zinc were 15.97 μg/L, 7.19 μg/L, 2.39 μg/L, 3.41 μg/L, 10.57 μg/L, 0.78 μg/L, 979.8 μg/L, 11.06 μg/L, 111.37 μg/L, and 872.7 μg/L, respectively. There were significant gender-related differences in the levels of several metals; male individuals had higher Pb, As, Cs, Hg, and Se than females, while females had higher Cd, Cu, and Mn than males. We noticed remarkably high blood levels of Hg, As and Al in the Korean population. The element concentrations reported represent a new contribution to the knowledge of the blood chemistry for the Korea population. The data can be used to assess the clinical health of this population.

Reference Values of 14 Serum Trace Elements for Pregnant Chinese Women: A Cross-Sectional Study in the China Nutrition and Health Survey 2010-2012

The development of reference values of trace elements is recognized as a fundamental prerequisite for the assessment of trace element nutritional status and health risks. In this study, a total of 1400 pregnant women aged 27.0 ± 4.5 years were randomly selected from the China Nutrition and Health Survey 2010–2012 (CNHS 2010–2012). The concentrations of 14 serum trace elements were determined by high-resolution inductively coupled plasma mass spectrometry. Reference values were calculated covering the central 95% reference intervals (P2.5–P97.5) after excluding outliers by Dixon’s test. The overall reference values of serum trace elements were 131.5 (55.8-265.0 μg/dL for iron (Fe), 195.5 (107.0–362.4) μg/dL for copper (Cu), 74.0 (51.8–111.3) μg/dL for zinc (Zn), 22.3 (14.0–62.0) μg/dL for rubidium (Rb), 72.2 (39.9–111.6) μg/L for selenium (Se), 45.9 (23.8-104.3) μg/L for strontium (Sr), 1.8 (1.2–3.6) μg/L for molybdenum (Mo), 2.4 (1.2–8.4) μg/L for manganese (Mn), 1.9 (0.6–9.0) ng/L for lead (Pb), 1.1 (0.3-5.6) ng/L for arsenic (As), 835.6 (219.8–4287.7) ng/L for chromium (Cr), 337.9 (57.0–1130.0) ng/L for cobalt (Co), 193.2 (23.6–2323.1) ng/L for vanadium (V), and 133.7 (72.1–595.1) ng/L for cadmium (Cd). Furthermore, some significant differences in serum trace element reference values were observed between different groupings of age intervals, residences, anthropometric status, and duration of pregnancy. We found that serum Fe, Zn, and Se concentrations significantly decreased, whereas serum Cu, Sr, and Co concentrations elevated progressively compared with reference values of 14 serum trace elements in pregnant Chinese women. The reference values of serum trace elements established could play a key role in the following nutritional status and health risk assessment.

A Prospective Study of Serum Trace Elements in Healthy Korean Pregnant Women

This prospective study sought to investigate serum levels of trace elements (cobalt, copper, zinc, and selenium) and to assess their effects on pregnancy and neonatal outcomes. Serum levels of trace elements in 245 Korean pregnant women (median gestational age at delivery was 39 + 4 weeks and interquartile range was 38 + 4–40 + 1 weeks) were compared with those of 527 general adults and those of previous studies in other ethnic groups. Pregnancy and neonatal outcomes including gestational diabetes, preeclampsia, neonatal birth weight, and congenital abnormalities were assessed. The median serum trace element concentrations of all pregnant women were: cobalt: 0.39 μg/L (interquartile range, IQR 0.29–0.53), copper: 165.0 μg/dL (IQR 144.0–187.0), zinc: 57.0 μg/dL (IQR 50.0–64.0), and selenium: 94.0 μg/L (IQR 87.0–101.0). Serum cobalt and copper concentrations were higher in pregnant women than in the general population, whereas zinc and selenium levels were lower (p < 0.01). Concentrations of all four trace elements varied significantly during the three trimesters (p < 0.05), and seasonal variation was found in copper, zinc, and selenium, but was not observed for cobalt. The prevalence of preeclampsia was significantly lower with high copper (p = 0.03). Trace element levels varied by pregnancy trimester and season, and alteration in copper status during pregnancy might influence pregnancy outcomes such as preeclampsia.

Serum Copper Status in School-Age Children and Pregnant Women in China Nutrition and Health Survey 2010-2012

Serum copper is an insensitive but reliable biomarker reflecting the change of copper nutritional status in both depleted and replete populations. The current study aimed to establish the reference values of serum copper in school-age children and pregnant women in China and to explore the adequate range of serum copper for both these two categories of people. A multistage, stratified, random sampling combined with probability proportionate to regional size sampling method was employed. A total of 4019 subjects (2736 school-age children and 1283 pregnant women) were selected from China Nutrition and Health Survey 2010-2012 (CNHS 2010-2012). The concentration of serum copper was determined by sector field inductively coupled plasma mass spectrometry (SF-ICP-MS). The adequate range of serum copper was determined by the logistic sigmoid saturation curve of the median derivatives. The median concentration of serum copper was 1140.9 μg/L with a range of 746.7-1677.6 μg/L for school-age children and 1933.4 μg/L with a range of 947.4-3391.4 μg/L for pregnant women. The adequate range of serum copper was 905.7-1440.7 μg/L for school-age children and 1308.8-2537.8 μg/L for pregnant women. These parameters represent an essential prerequisite for the assessment of copper nutritional status, as well as nutrition interventions.

Trace metal levels in serum and urine of a population in southern Brazil

This study aimed to evaluate serum and urine concentrations of several trace metals of a non-directly exposed population in southern Brazil and establish reference values. Serum and urine samples were obtained from 240 volunteers (175 males and 65 females, age ranging from 18 to 74 years old). Levels of arsenic, chromium, cobalt, copper, lead, nickel, manganese and zinc were determined by means of dynamic reaction cell inductively coupled plasma mass spectrometry (DRC-ICP-MS). Comparison between genders resulted in no significant difference for all metals but serum copper, as concentrations are higher in females than males. For most metals assessed, a negative correlation between serum concentrations and age was found, but no significant correlation was found between urine concentrations and age.

Zinc and copper status in childbearing age Tunisian women: Relation to age, residential area, socioeconomic situation and physiologic characteristics

Plasma zinc and copper status of 1689 non pregnant Tunisian women, aged 20-49 years old, was determined by flame atomic absorption spectrometry. A multiple regression was run to predict plasma trace element concentrations from age, BMI, marital status, menopause, education level, professional activity, economic level and area of living. The mean zinc and copper values were similar to those measured among comparable populations in earlier studies. However, a high prevalence of low plasma zinc and copper concentrations was observed assuming that women at childbearing age are at high risk of zinc and copper deficiencies and specific intervention may be considered. In univariate analysis, the mean values of plasma zinc and copper were associated with sitting areas and professional activity. For only plasma copper levels, there was an increase with BMI and parity, and a decrease with increasing schooling level and economic score. After adjustment for all variables, profession and parity showed a significant relationship between plasma levels copper.

Is Routine Iron Supplementation Necessary in Pregnant Women With High Hemoglobin?

Background:

Iron supplementation is a chief component in prenatal care, with the aim of preventing anemia; however, extreme maternal iron status may adversely affect the birth outcome. Given the negative consequences of high maternal iron concentrations on pregnancy outcomes, it seems that iron supplementation in women with high hemoglobin (Hb) should be limited.

Objectives:

The aim of this study was to examine the effect of iron supplementation on iron status markers in pregnant women with high Hb.

Patients and Methods:

In a randomized, double-blind, placebo-controlled trial, 86 pregnant women with Hb > 13.2 g/dL and ferritin > 15 μg/l in the 16th - 20th week of pregnancy were randomized into experimental and control groups. From the 20th week until the end of pregnancy, the experimental group received one ferrous sulfate tablet containing 50 mg of elemental iron daily, while the control group received a placebo. Hb and ferritin levels at 37 - 39 weeks of pregnancy were evaluated and compared. In addition, after delivery the birth weight was measured in two groups and compared.

Results:

There were statistically significant differences between the two groups in Hb (p = 0/03) and ferritin (p = 0/04) levels at the end of pregnancy, but the incidence of anemia exhibited no difference in either group (p < 0/001). In addition, the mean of birth weight in experimental group and control group were 3391/56 ± 422, 3314/06 ± 341, respectively and it was not significant difference (p = 0.2).

Conclusions:

Not using iron supplementation did not cause of anemia in women with Hb concentrations greater than 13.2 g/dL during pregnancy; thus, the systematic care and control of iron status markers without iron supplementation is recommended for these women.

Interdependence between urinary cobalt concentrations and hemoglobin levels in pregnant women

Cobalt is an essential trace element but may cause toxic effects upon occupational or environmental exposure. Women accumulate more cobalt than men at similar exposure levels which may be related to higher metabolic iron loss. During pregnancy these losses are much stronger but their influence on cobalt intake has not been studied. We have studied the associations between changes in hemoglobin and cobalt urinary excretion during pregnancy. 391 pairs of urine and blood samples from pregnant women were collected during the 12th and 32nd weeks of pregnancy and were analyzed for cobalt and hemoglobin. Mean concentrations of urinary cobalt were 0.73 and 1.6 µg/g creatinine during the first and third trimesters, respectively (p<0.001). 84% of pregnant women had higher levels of cobalt in the third than in the first trimester. Cobalt concentrations were negatively associated to hemoglobin levels in the third trimester (p<0.05). Women with higher iron decreases between both trimesters had significant cobalt increases between these two periods. This correspondence involved a statistically significant difference in third trimester mean cobalt concentrations of anemic and non-anemic women, 1.8 and 1.5 µg/g creatinine, respectively (p<0.05). No significant differences between these two groups were found during the first trimester. These results were used to construct generalized additive models both in normal and anemic women. The strong association between the changes of both iron status and cobalt urine levels found in pregnant women may be related to higher intestinal absorption of cobalt at iron depletion such as in the last pregnancy period when iron body demands are high. Possible toxicity effects of these cobalt increases along pregnancy should be considered in cases of populations occupationally or environmentally exposed to this metal.

Correlations among antiangiogenic factors and trace elements in hypertensive disorders of pregnancy

Although a number of studies have measured circulating levels of some trace elements in preeclampsia (PE) and compared to healthy pregnant (HP), there is no consensus yet about the deficiency of some metals and development of hypertensive disorders in pregnancy. The aim of this study was to compare plasmatic levels of Zn, Mn, Co, Cu, Se and Sr among non-pregnant (NP), healthy pregnant (HP), gestational hypertensive (GH) and preeclamptic (PE) women and to correlate these levels with plasma soluble endoglin (sENG) and soluble fms-like tyrosine kinase-1 (sFLT-1), two important antiangiogenic proteins related to PE. A total of 184 women were enrolled in this study (NP=35, GH=51, PE=37 and HP=61). Trace element analyses were carried out with an inductively coupled plasma mass spectrometer (ICPMS). sENG and sFLT-1 plasma concentrations were measured by commercial ELISA kits. The most interesting result is that Sr is higher in PE (63%, P<0.001) compared to HP and their levels are positively correlated with sENG in all three groups of pregnant women. Moreover, we found a negative correlation between Zn and sENG in HP (r=-0.43, P=0.003). Regarding other elements, we found similar levels among pregnant groups. In conclusion, this study showed that Sr may has a role in physiopathology of PE.

Zinc: The Metal of Life

The importance of zinc was 1st reported for Aspergillus niger. It took over 75 y to realize that zinc is also an essential trace element for rats, and an additional 30 y went by before it was recognized that this was also true for humans. The adult body contains about 2 to 3 g of zinc. Zinc is found in organs, tissues, bones, fluids, and cells. It is essential for many physiological functions and plays a significant role in a number of enzyme actions in the living systems. Bioinformatics estimates report that 10% of the human proteome contains zinc-binding sites. Based on its role in such a plethora of cellular components, zinc has diverse biological functions from enzymatic catalysis to playing a crucial role in cellular neuronal systems. Thus, based on the various published studies and reports, it is pertinent to state that zinc is one of the most important essential trace metals in human nutrition and lifestyle. Its deficiency may severely affect the homeostasis of a biological system. This review compiles the role of zinc in prophylaxis/therapeutics and provides current information about its effect on living beings.

Elements in maternal blood and amniotic fluid determined by ICP-MS

OBJECTIVE

Knowledge about levels of toxic and non-toxic elements in amniotic fluid is limited. The aims of this study were: (1) to measure levels of trace elements Cu, Fe, Zn, B, Sr and Co in amniotic fluid and maternal serum during second trimester of pregnancy; and (2) to determine what correlations exists between elements levels in amniotic fluid and maternal serum.

METHODS

The levels of, iron, copper, zinc, cobalt, strontium and boron were measured in blood and amniotic fluid during genetic amniocentesis using inductively coupled plasma mass spectrometry (ICP-MS).

RESULTS

Concentrations of the elements: Fe, Cu, Zn, Co, Sr and B in amniotic fluid were significantly lower than in maternal blood. For iron, zinc, cobalt, strontium and boron there was a linear correlation between levels in amniotic fluid and maternal serum.

CONCLUSIONS

The concentration of trace elements in amniotic fluid was found to be lower than maternal serum and linearly correlated to its level.

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.

Determination of selenium in serum samples of preterm newborn infants with bronchopulmonary dysplasia using a validated hydride generation system

Bronchopulmonary dysplasia (BPD), also known as chronic lung disease, is one of the most challenging complications in premature newborn infants. Selenium plays a role in antioxidant system by protecting cell membranes and neutralizing the deleterious effects of free radicals. The aim of this study was to determine the relationship between selenium concentration and incidence of bronchopulmonary dysplasia using a validated analytical method. Umbilical cord blood and blood samples 30 days after the birth were collected from 38 preterm newborn infants with gestation age of 32 weeks or less, and the separated serums were kept at -70°C until analysis time. Selenium concentration of serum was determined using an atomic absorption spectrophotometer. The method was validated on the basis of standard validation techniques. The analytical method was linear in the range of 1 to 500 μg/L with the limit of detection of 0.4 μg/L. Samples were collected from 38 infants whose gestation age was 32 weeks or less. The blood samples were collected from the umbilical cord blood at birth in 19 cases. In 25 cases, blood samples were collected 1 month after birth. Of the 15 patients diagnosed with BPD, 10 were boys (p = 0.02). The mean serum selenium concentration was not different at birth between patients with and without BPD, but it was significantly lower at 30 days after birth in patients with BPD (38.5 ± 14.1vs. 45.4 ± 18.7 μg/L, p = 0.02). Preterm newborn infants with BPD had lower serum selenium concentrations 1 month after birth.

Plasma selenium concentrations in pregnant women in two countries with contrasting soil selenium levels

PROJECT

Selenium has an important role in antioxidant defense and cell mediated immunity. Plasma selenium is a useful biomarker for comparing selenium status across populations, and influenced by selenium levels of soils and plants.

PROCEDURE

This cross-sectional study compared plasma selenium (by electrothermal atomic absorption spectrophotometry) of women at 24 weeks gestation in Malawi (n=152) and the Philippines (n=301), countries with low and high soil selenium levels, respectively. Data on anthropometry, smoking, intakes of energy, nutrients and food groups (via 24-h recalls), hemoglobin, serum zinc, and C-reactive protein (CRP) were also collected.

RESULTS

Mean (95% CI) plasma selenium was lower for Malawian than Filipino women (0.79, 0.77, 0.82 μmol/L vs. 1.44, 1.41, 1.47 μmol/L; p<0.001); 83% had concentrations below 1.0 μmol/L compared to 3% in the Filipinos. Cereals provided 78% and 67% of the energy in Malawi and the Philippines, respectively compared to 4% and 8.5%, respectively for cellular animal protein. Plasma selenium was correlated modestly with BMI (r=-0.138; p=0.096) and elevated CRP (>5.0 mg/L) (r=-0.143; p=0.084) in Malawi, and significantly with intake of cellular animal protein (g/d) (r=0.23; p=0.020) and serum zinc (r=0.13; p=0.044) in the Philippines. No comparable relationships were observed in either group for smoking, hemoglobin, or cereal intakes.

CONCLUSION

Differences in plasma selenium paralleled reported trends in selenium concentrations in soils and staple cereals in Malawi and the Philippines. The biological significance of the lower plasma selenium for the Malawian women, and the extent to which they pose a risk for fetal and neonatal development, is uncertain.

Changes in maternal blood concentrations of selected essential and toxic elements during and after pregnancy

The objective of this study was to investigate changes in the levels of toxic and essential elements in maternal blood during pregnancy and subsequently. A subset of 211 pregnant women from the North Norwegian Mother-and-Child Study was included. Blood samples were collected during the 2(nd) trimester (P1) and postpartum (day 3, P2; and 6 weeks, P3) in different regions of northern Norway, and were analyzed for a suite of 10 selected elements. The latter feature three general but distinct concentration patterns across the three collection periods, namely: progressive increase [Group 1: As, Cd (non-smokers only), Mn, Pb and Zn]; V-shaped, with a minimum at P2 [Group 2: Cd (smokers), Hg, Mo and Se]; and downward V, with a maximum at P2 [Group 3: Co and Cu]. These trends are interpreted in the context of underlying metabolic, hematological and physiological changes that occur in mothers, as well the biochemistry and accumulation preferences of these elements within the whole blood compartment and breast milk. Implications for biomonitoring strategies are discussed. In a multivariable analysis of the P1 data, fish consumption was a robust positive predictor for Hg (p < 0.02), As (p < 0.01) and Se (p ≤ 0.001) blood concentrations, multivitamin intake for Se (p < 0.001), and parity for Co (p < 0.002); age reached significance only for Hg (p < 0.001). An inverse association was observed between parity and Hg (p < 0.05). For the other elements, predictor patterns were not evident.