Gestational exposure to organochlorine compounds and metals and infant birth weight: effect modification by maternal hardships.

BACKGROUND: Gestational exposure to toxic environmental chemicals and maternal social hardships are individually associated with impaired fetal growth, but it is unclear whether the effects of environmental chemical exposure on infant birth weight are modified by maternal hardships. METHODS: We used data from the Maternal-Infant Research on Environmental Chemicals (MIREC) Study, a pan-Canadian cohort of 1982 pregnant females enrolled between 2008 and 2011. We quantified eleven environmental chemical concentrations from two chemical classes - six organochlorine compounds (OCs) and five metals - that were detected in ≥ 70% of blood samples collected during the first trimester. We examined fetal growth using birth weight adjusted for gestational age and assessed nine maternal hardships by questionnaire. Each maternal hardship variable was dichotomized to indicate whether the females experienced the hardship. In our analysis, we used elastic net to select the environmental chemicals, maternal hardships, and 2-way interactions between maternal hardships and environmental chemicals that were most predictive of birth weight. Next, we obtained effect estimates using multiple linear regression, and plotted the relationships by hardship status for visual interpretation. RESULTS: Elastic net selected trans-nonachlor, lead, low educational status, racially minoritized background, and low supplemental folic acid intake. All were inversely associated with birth weight. Elastic net also selected interaction terms. Among those with increasing environmental chemical exposures and reported hardships, we observed stronger negative associations and a few positive associations. For example, every two-fold increase in lead concentrations was more strongly associated with reduced infant birth weight among participants with low educational status (ß = -100 g (g); 95% confidence interval (CI): -215, 16), than those with higher educational status (ß = -34 g; 95% CI: -63, -3). In contrast, every two-fold increase in mercury concentrations was associated with slightly higher birth weight among participants with low educational status (ß = 23 g; 95% CI: -25, 71) compared to those with higher educational status (ß = -9 g; 95% CI: -24, 6). CONCLUSIONS: Our findings suggest that maternal hardships can modify the associations of gestational exposure to some OCs and metals with infant birth weight.

Associations of toxic metals and their mixture with hyperuricemia in Chinese rural older adults.

Previous studies have related single toxic metals (TMs) to hyperuricemia (HUA) among the general population, however, the association of the TM mixture with HUA, especially in older adults, remains poorly understood. We aimed to examine the relationships between individual TMs and their mixture and HUA in Chinese rural older adults. This study consisted of 2075 rural older adults aged 60 years or over. Blood concentrations of aluminum (Al), arsenic (As), barium (Ba), cadmium (Cd), cesium (Cs), gallium (Ga), mercury (Hg), lead (Pb), thallium (Tl), and uranium (U) were detected using inductively coupled plasma mass spectrometry. The associations of single TMs with HUA were assessed using logistic regression and restricted cubic spline (RCS) models, and the association of TM mixture with HUA was explored using the elastic net with environmental risk score (ENET-ERS), quantile g-computation (QGC), and Bayesian kernel machine regression (BKMR) models, respectively. Adjusted logistic regression model showed that Cs (OR = 1.65, 95% CI 1.37-1.99) and Pb (OR = 1.46, 95% CI 1.28-1.67) were positively related to HUA, and RCS model exhibited a positive linear association of Cs and Pb with HUA. ENET-ERS and QGC models quantified a positive correlation between the TM mixture and the odds of HUA, with estimated ORs of 1.15 (95% CI 1.11-1.19) and 1.84 (95% CI 1.37-2.47), respectively, and Cs and Pb had the most weight. BKMR model demonstrated a significant linear association between the TM mixture and increased odds of HUA, with the posterior inclusion probabilities (PIPs) of both Cs and Pb being 1.00. Moreover, we observed a positive interaction between Cs and Pb on HUA. The TM mixture is associated with increased odds of HUA in rural older adults, which may mainly be driven by Cs and Pb. Subsequent studies are warranted to confirm these findings and clarify the mechanisms linking multiple TMs with HUA.

Associations of mixed metal exposure with chronic kidney disease from NHANES 2011-2018.

Metals have been proved to be one of risk factors for chronic kidney disease (CKD) and diabetes, but the effect of mixed metal co-exposure and potential interaction between metals are still unclear. We assessed the urine and whole blood levels of cadmium (Cd), manganese (Mn), lead (Pb), mercury (Hg), and renal function in 3080 adults from National Health and Nutrition Survey (NHANES) (2011-2018) to explore the effect of mixed metal exposure on CKD especially in people with type 2 diabetes mellitus (T2DM). Weighted quantile sum regression model and Bayesian Kernel Machine Regression model were used to evaluate the overall exposure impact of metal mixture and potential interaction between metals. The results showed that the exposure to mixed metals was significantly associated with an increased risk of CKD in blood glucose stratification, with the risk of CKD being 1.58 (1.26,1.99) times in urine and 1.67 (1.19,2.34) times in whole blood higher in individuals exposed to high concentrations of the metal mixture compared to those exposed to low concentrations. The effect of urine metal mixture was elevated magnitude in stratified analysis. There were interactions between urine Pb and Cd, Pb and Mn, Pb and Hg, Cd and Mn, Cd and Hg, and blood Pb and Hg, Mn and Cd, Mn and Pb, Mn and Hg on the risk of CKD in patients with T2DM and no significant interaction between metals was observed in non-diabetics. In summary, mixed metal exposure increased the risk of CKD in patients with T2DM, and there were complex interactions between metals. More in-depth studies are needed to explore the mechanism and demonstrate the causal relationship.

Association of exposure to multiple metals with hemoglobin levels in Chinese children and adolescents.

BACKGROUND: Previous studies have linked single metal to hemoglobin levels in children and adolescents; however, studies with regards to metal mixtures are still limited. OBJECTIVE: We aimed to investigate the associations of single metal and metal mixtures with hemoglobin levels in children and adolescents. METHODS: We conducted a cross-sectional study of 2064 children and adolescents aged 6 to 19 years in Liuzhou, China in 2018. The concentrations of 15 metals in urine were determined by inductively coupled plasma mass spectrometry. Generalized linear regression and weighted quantile sum (WQS) regression were used to estimate the associations of single metal and metal mixtures with hemoglobin levels, respectively. RESULTS: The multivariable-adjusted ß-values for the highest versus the first quartiles of urinary metal concentrations were - 1.57 (95 % confidence interval [CI]: -3.01, -0.13) for chromium, -2.47 (95 % CI: -3.90, -1.05) for nickel and 1.88 (95 % CI: 0.49, 3.28) for copper. In addition, we found a significant negative association between the WQS index and hemoglobin levels (adjusted ß = -0.93, 95 % CI: -1.69, -0.19), with nickel contributing the most to the WQS index at 59.0 %. Subgroup analyses showed that exposure to urinary nickel or metal mixtures were associated with decreased hemoglobin levels in adolescents, but not in children (all Pinteration < 0.001). CONCLUSION: Among children and adolescents, urinary chromium and nickel concentrations were associated with decreased hemoglobin levels, while copper showed a positive relationship. Moreover, a negative association was observed between exposure to metal mixtures and hemoglobin levels. These findings need to be further validated in prospective studies.

Associations among neighborhood walkability, metal exposure, and sex steroid hormone levels: Results from Hangzhou Birth Cohort Study â ¡.

BACKGROUND: Neighborhood walkability may influence maternal-fetal exposure to environmental hazards and maternal-fetal health (e.g., fetal growth restriction, reproductive toxicity). However, few studies have explored the association between neighborhood walkability and hormones in pregnant women. METHODS: We included 533 pregnant women from the Hangzhou Birth Cohort Study II (HBCS-II) with testosterone (TTE) and estradiol (E2) measured for analysis. Neighborhood walkability was evaluated by calculating a walkability index based on geo-coded addresses. Placental metals were measured using inductively coupled plasma mass spectrometry (ICP-MS). TTE and E2 levels in umbilical cord blood were measured using chemiluminescence microparticle immunoassay (CMIA). Linear regression model was used to estimate the relationship between the walkability index, placental metals, and sex steroid hormones. Effect modification was also assessed to estimate the effect of placental metals on the associations of neighborhood walkability with TTE and E2. RESULTS: Neighborhood walkability was significantly linked to increased E2 levels (P trend=0.023). Compared with participants at the first quintile (Q1) of walkability index, those at the third quintiles (Q3) had lower chromium (Cr) levels (ß = -0.212, 95% CI = -0.421 to -0.003). Arsenic (As), cobalt (Co), manganese (Mn), molybdenum (Mo), nickel (Ni), lead (Pb), antimony (Sb), selenium (Se), tin (Sn), and vanadium (V) were linked to decreased TTE levels, and cadmium (Cd) was linked to increased TTE levels. No metal was significantly associated with E2 levels in trend analysis. In the analysis of effect modification, the associations of neighborhood walkability with TTE and E2 were significantly modified by Mn (P = 0.005) and Cu (P = 0.049) respectively. CONCLUSION: Neighborhood walkability could be a favorable factor for E2 production during pregnancy, which may be inhibited by maternal exposure to heavy metals.

Comparative mathematical modeling of causal association between metal exposure and development of chronic kidney disease.

Background: Previous studies have identified several genetic and environmental risk factors for chronic kidney disease (CKD). However, little is known about the relationship between serum metals and CKD risk. Methods: We investigated associations between serum metals levels and CKD risk among 100 medical examiners and 443 CKD patients in the medical center of the First Hospital Affiliated to China Medical University. Serum metal concentrations were measured using inductively coupled plasma mass spectrometry (ICP-MS). We analyzed factors influencing CKD, including abnormalities in Creatine and Cystatin C, using univariate and multiple analysis such as Lasso and Logistic regression. Metal levels among CKD patients at different stages were also explored. The study utilized machine learning and Bayesian Kernel Machine Regression (BKMR) to assess associations and predict CKD risk based on serum metals. A chained mediation model was applied to investigate how interventions with different heavy metals influence renal function indicators (creatinine and cystatin C) and their impact on diagnosing and treating renal impairment. Results: Serum potassium (K), sodium (Na), and calcium (Ca) showed positive trends with CKD, while selenium (Se) and molybdenum (Mo) showed negative trends. Metal mixtures had a significant negative effect on CKD when concentrations were all from 30th to 45th percentiles compared to the median, but the opposite was observed for the 55th to 60th percentiles. For example, a change in serum K concentration from the 25th to the 75th percentile was associated with a significant increase in CKD risk of 5.15(1.77,8.53), 13.62(8.91,18.33) and 31.81(14.03,49.58) when other metals were fixed at the 25th, 50th and 75th percentiles, respectively. Conclusions: Cumulative metal exposures, especially double-exposure to serum K and Se may impact CKD risk. Machine learning methods validated the external relevance of the metal factors. Our study highlights the importance of employing diverse methodologies to evaluate health effects of metal mixtures.

Associations between maternal exposure to multiple metals and metalloids and blood pressure in preschool children: A mixture-based approach.

BACKGROUND: Exposure to metals during pregnancy can potentially influence blood pressure (BP) in children, but few studies have examined the mixed effects of prenatal metal exposure on childhood BP. We aimed to assess the individual and combined effects of prenatal metal and metalloid exposure on BP in preschool children. METHODS: A total of 217 mother-child pairs were selected from the Zhuang Birth Cohort in Guangxi, China. The maternal plasma concentrations of 20 metals [e.g. lead (Pb), rubidium (Rb), cesium (Cs), and zinc (Zn)] in early pregnancy were measured by inductively coupled plasmamass spectrometry. Childhood BP was measured in August 2021. The effects of prenatal metal exposure on childhood BP were explored by generalized linear models, restricted cubic spline and Bayesian kernel machine regression (BKMR) models. RESULTS: In total children, each unit increase in the log10-transformed maternal Rb concentration was associated with a 10.82-mmHg decrease (95% CI: -19.40, -2.24) in childhood diastolic BP (DBP), and each unit increase in the log10-transformed maternal Cs and Zn concentrations was associated with a 9.67-mmHg (95% CI: -16.72, -2.61) and 4.37-mmHg (95% CI: -8.68, -0.062) decrease in childhood pulse pressure (PP), respectively. The log10-transformed Rb and Cs concentrations were linearly related to DBP (P nonlinear=0.603) and PP (P nonlinear=0.962), respectively. Furthermore, an inverse association was observed between the log10-transformed Cs concentration and PP (ß =-12.18; 95% CI: -22.82, -1.54) in girls, and between the log10-transformed Rb concentration and DBP (ß =-12.54; 95% CI: -23.87, -1.21) in boys, while there was an increasing association between the log10-transformed Pb concentration and DBP there was an increasing in boys (ß =6.06; 95% CI: 0.36, 11.77). Additionally, a U-shaped relationship was observed between the log10-transformed Pb concentration and SBP (P nonlinear=0.015) and DBP (P nonlinear=0.041) in boys. Although there was no statistically signiffcant difference, there was an inverse trend in the combined effect of maternal metal mixture exposure on childhood BP among both the total children and girls in BKMR. CONCLUSIONS: Prenatal exposure to both individual and mixtures of metals and metalloids influences BP in preschool children, potentially leading to nonlinear and sex-specific effects.

Association between plasma metal exposure and health span in very elderly adults: a prospective cohort study with mixture statistical approach.

BACKGROUND: Metals have been linked to a diverse spectrum of age-related diseases; however, the effects of metal exposure on health span remains largely unknown. This cohort study aims to determine the association between plasma metal and health span in elder adults aged ≥ 90 years. METHODS: The plasma concentrations of seven metals were measured at baseline in 300 elder adults. The end of the health span (EHS) was identified as the occurrence of one of eight major morbidities or mortality events. We used Cox regression to assess hazard ratios (HR). The combined effects of multiple metal mixtures were estimated using grouped-weighted quantile sum (GWQS), quantile g-computation (Q-gcomp), and Bayesian kernel machine regression (BKMR) methods. RESULTS: The estimated HR for EHS with an inter-quartile range (IQR) increment for selenium (Se) was 0.826 (95% confidence interval [CI]: 0.737-0.926); magnesium (Mg), 0.806 (95% CI: 0.691-0.941); iron (Fe), 0.756 (95% CI: 0.623-0.917), and copper (Cu), 0.856 (95% CI: 0.750-0.976). The P for trend of Se, Mg, and Fe were all < 0.05. In the mixture analyses, Q-gcomp showed a negative correlation with EHS (P = 0.904), with the sum of the negative coefficients being -0.211. CONCLUSION: Higher plasma Se, Mg, and Fe reduced the risk of premature end of health span, suggesting that essential metal elements played a role in health maintenance in elder adults.

Associations between seminal plasma metals/metalloids and semen quality: A cross-sectional study.

Exposure to metals/metalloids is reported to potentially influence semen quality. While most studies have focused on single metal impacts, the link between exposure to multiple metals and semen quality has remained less explored. The study aimed to investigate the effects of both individual and mixed metal/metalloid exposure on semen quality. A total of 330 men were recruited from three reproductive centers in eastern China. Seminal plasma levels of 25 metals/metalloids and sperm parameters were determined. We used the Generalized Linear Model (GLM) and Restricted Cubic Spline (RCS) to assess the relationships between single metals/metalloids and semen quality. The weighted quantile sum (WQS) models were then applied to evaluate the combined effect of all these metals/metalloids. We observed positive associations of exposure to lithium (Li), zinc (Zn), and magnesium (Mg) with an increased risk of below reference values for progressive motility and total motility using a logistic regression model (P < 0.05). Additionally, our results also revealed a significant inverse relationship between aluminum (Al) and both sperm concentration and count, while cobalt (Co) demonstrated a positive association with sperm concentration (P < 0.05). Notably, the WQS model indicated a significant positive association between exposure to metal/metalloid mixtures and the risk of abnormal progressive motility (OR: 1.57; 95%CI: 1.10, 2.24) and abnormal total motility (OR: 1.53; 95%CI: 1.06, 2.19), with this association primarily driven by Li, Mg, and Zn. In summary, our findings indicate that exposure to metal/metalloid mixtures might have an adverse effect on semen quality.

Association of serum metal levels with type 2 diabetes: A prospective cohort and mediating effects of metabolites analysis in Chinese population.

Several studies have suggested an association between exposure to various metals and the onset of type 2 diabetes (T2D). However, the results vary across different studies. We aimed to investigate the associations between serum metal concentrations and the risk of developing T2D among 8734 participants using a prospective cohort study design. We utilized inductively coupled plasmamass spectrometry (ICP-MS) to assess the serum concentrations of 27 metals. Cox regression was applied to calculate the hazard ratios (HRs) for the associations between serum metal concentrations on the risk of developing T2D. Additionally, 196 incident T2D cases and 208 healthy control participants were randomly selected for serum metabolite measurement using an untargeted metabolomics approach to evaluate the mediating role of serum metabolite in the relationship between serum metal concentrations and the risk of developing T2D with a nested casecontrol study design. In the cohort study, after Bonferroni correction, the serum concentrations of zinc (Zn), mercury (Hg), and thallium (Tl) were positively associated with the risk of developing T2D, whereas the serum concentrations of manganese (Mn), molybdenum (Mo), barium (Ba), lutetium (Lu), and lead (Pb) were negatively associated with the risk of developing T2D. After adding these eight metals, the predictive ability increased significantly compared with that of the traditional clinical model (AUC: 0.791 vs. 0.772, P=8.85×10-5). In the nested casecontrol study, a machine learning analysis revealed that the serum concentrations of 14 out of 1579 detected metabolites were associated with the risk of developing T2D. According to generalized linear regression models, 7 of these metabolites were significantly associated with the serum concentrations of the identified metals. The mediation analysis showed that two metabolites (2-methyl-1,2-dihydrophthalazin-1-one and mestranol) mediated 46.81% and 58.70%, respectively, of the association between the serum Pb concentration and the risk of developing T2D. Our study suggested that serum Mn, Zn, Mo, Ba, Lu, Hg, Tl, and Pb were associated with T2D risk. Two metabolites mediated the associations between the serum Pb concentration and the risk of developing T2D.

Metal exposure and blood lipid biomarkers in early pregnancy: A cross-sectional study.

Recognizing the risk factors for dyslipidemia during pregnancy is crucial for safeguarding the health of both the mothers and the offspring. Growing evidence emerged and suggested links between environmental factors, including metals, and alteration in lipid levels or dyslipidemia in general populations. However, knowledge of the associations during pregnancy remains extremely lacking. Herein, we aimed to explore whether elevated metal exposure constitutes a risk factor for dyslipidemia in pregnant women. Based on the Tongji-Shuangliu Birth Cohort (TSBC), a total of 663 pregnant women were recruited and their urinary levels of 17 metals and blood lipid biomarkers in early pregnancy were measured, namely triglyceride (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), and high-density lipoprotein cholesterol (HDL-C). The multivariable linear regression models revealed that exposure to selected metals during early pregnancy was significantly associated with some important biomarkers. In particular, after natural log-transformed for the levels of lipid biomarkers and metals, copper (Cu) exposure was positively associated with HDL-C (ß = 0.024, 95% CI: 0.001, 0.046), while zinc (Zn) was associated with TG (ß = 0.062, 95% CI: 0.013, 0.110) and selenium with TC (ß = 0.028, 95% CI: 0.004, 0.054). Exposure to rubidium (Rb) was positively associated with multiple lipid biomarkers, including HDL-C (ß = 0.020, 95% CI: 0.002, 0.037) and LDL-C (ß = 0.022, 95% CI: 0.001, 0.042). Mixture exposure analysis further identified significant associations between Cu and HDL-C, Zn and TG, Rb and HDL-C, when multiple metal exposures were considered in the Bayesian kernel machine regression model simultaneously. Our findings showed that exposure to several metals during early pregnancy was associated with an increased prevalence of blood lipid abnormalities in pregnant women. These findings underscore the potential impact of metal combinations on lipid metabolism and increase our understanding of the risk factors associated with abnormal lipid metabolism during pregnancy.

Effects of multiple metals exposure on abnormal liver function: The mediating role of low-density lipoprotein cholesterol.

Equilibration of metal metabolism is critical for normal liver function. Most epidemiological studies have only concentrated on the influence of limited metals. However, the single and synergistic impact of multiple-metal exposures on abnormal liver function (ALF) are still unknown. A cross-sectional study involving 1493 Chinese adults residing in Shenzhen was conducted. Plasma concentrations of 13 metals, including essential metals (calcium, copper, cobalt, iron, magnesium, manganese, molybdenum, zinc, and selenium) and toxic metals (aluminum, cadmium, arsenic, and thallium) were detected by the inductively coupled plasma spectrometry (ICP-MS). ALF was ascertained as any observed abnormality from albumin, alanine transaminase, aspartate transaminase, γ-glutamyl transpeptidase, and direct bilirubin. Diverse statistical methods were used to evaluate the single and mixture effect of metals, as well as the dose-response relationships with ALF risk, respectively. Mediation analysis was conducted to evaluate the role of blood lipids in the relation of metal exposure with ALF. The average age of subjects was 59.7 years, and 56.7 % were females. Logistic regression and the least absolute shrinkage and selection operator (LASSO) penalized regression model consistently suggested that increased levels of arsenic, aluminum, manganese, and cadmium were related to elevated risk of ALF; while magnesium and zinc showed protective effects on ALF (all p-trend < 0.05). The grouped weighted quantile sum (GWQS) regression revealed that the WQS index of essential metals and toxic metals showed significantly negative or positive relationship with ALF, respectively. Aluminum, arsenic, cadmium, and manganese showed linear whilst magnesium and zinc showed non-linear dose-response relationships with ALF risk. Mediation analysis showed that LDL-c mediated 4.41 % and 14.74 % of the relationship of plasma cadmium and manganese with ALF, respectively. In summary, plasma aluminum, arsenic, manganese, cadmium, magnesium, and zinc related with ALF, and LDL-c might underlie the pathogenesis of ALF associated with cadmium and manganese exposure. This study may provide critical public health significances in liver injury prevention and scientific evidence for the establishment of environmental standard.

Associations of maternal blood metal concentrations with plasma eicosanoids among pregnant women in Puerto Rico.

BACKGROUND/AIM: Heavy metals are known to induce oxidative stress and inflammation, and the association between metal exposure and adverse birth outcomes is well established. However, there lacks research on biomarker profiles linking metal exposures and adverse birth outcomes. Eicosanoids are lipid molecules that regulate inflammation in the body, and there is growing evidence that suggests associations between plasma eicosanoids and pregnancy outcomes. Eicosanoids may aid our understanding of etiologic birth pathways. Here, we assessed associations between maternal blood metal concentrations with eicosanoid profiles among 654 pregnant women in the Puerto Rico PROTECT birth cohort. METHODS: We measured concentrations of 11 metals in whole blood collected at median 18 and 26 weeks of pregnancy, and eicosanoid profiles measured in plasma collected at median 26 weeks. Multivariable linear models were used to regress eicosanoids on metals concentrations. Effect modification by infant sex was explored using interaction terms. RESULTS: A total of 55 eicosanoids were profiled. Notably, 12-oxoeicosatetraenoic acid (12-oxoETE) and 15-oxoeicosatetraenoic acid (15-oxoETE), both of which exert inflammatory activities, had the greatest number of significant associations with metal concentrations. These eicosanoids were associated with increased concentrations of Cu, Mn, and Zn, and decreased concentrations of Cd, Co, Ni, and Pb, with the strongest effect sizes observed for 12-oxoETE and Pb (ß:-33.5,95 %CI:-42.9,-22.6) and 15-oxoETE and Sn (ß:43.2,95 %CI:11.4,84.1). Also, we observed differences in metals-eicosanoid associations by infant sex. Particularly, Cs and Mn had the most infant sex-specific significant associations with eicosanoids, which were primarily driven by female fetuses. All significant sex-specific associations with Cs were inverse among females, while significant sex-specific associations with Mn among females were positive within the cyclooxygenase group but inverse among the lipoxygenase group. CONCLUSION: Certain metals were significantly associated with eicosanoids that are responsible for regulating inflammatory responses. Eicosanoid-metal associations may suggest a role for eicosanoids in mediating metal-induced adverse birth outcomes.

Elevated blood metal ion levels in patients undergoing instrumented spinal surgery: a systematic review and meta-analysis.

BACKGROUND CONTEXT: Elevated blood metal levels have been reported in patients after spinal surgery using metallic implants. Although some studies have suggested an association between heightened blood metal concentrations and potential adverse effects, estimates of the incidence of abnormal metal levels after spinal surgery have been inconsistent. PURPOSE: The aims of this systematic review and meta-analysis were to assess: (1) mean differences in blood metal ion levels between patients undergoing spinal fusion surgery and healthy controls, (2) odds of elevated blood metal ion levels after surgery compared to presurgery levels, and (3) pooled incidence of elevated blood metal ions overall and by metal type. STUDY DESIGN: Systematic review and meta-analysis. PATIENTS SAMPLE: The patient sample included 613 patients from 11 studies who underwent spinal surgery instrumentation. OUTCOME MEASURES: Blood metal ion concentrations and the incidence of patients with elevated metal levels compared with in those the control group. METHODS: A comprehensive search was conducted in PubMed, EMBASE, Scopus, and Cochrane Library to identify studies reporting blood metal ion levels after spinal fusion surgery. Mean differences (MD), odds ratios (OR), and incidence rates were pooled using random effects models. Heterogeneity was assessed using I2 statistics, and fixed-effects models were used if no heterogeneity was detected. Detailed statistical analysis was performed using the Review Manager version 5.4 software. RESULTS: The analysis included 11 studies, with a total of 613 patients. Mean blood metal ion levels were significantly higher after spinal fusion surgery (MD 0.56, 95% CI 0.17-0.96; I2=86%). Specifically, titanium levels were significantly elevated (MD 0.81, 95% CI 0.32-1.30; I2=47%). The odds of elevated blood metal ions were higher after surgery (OR 8.17, 95% CI 3.38-19.72; I2=41%), primarily driven by chromium (OR 23.50, 95% CI 5.56-99.31; I2=30%). The incidence of elevated chromium levels was found to be 66.98% (95% CI 42.31-91.65). CONCLUSION: In conclusion, blood metal ion levels, particularly titanium and chromium, were significantly increased after spinal fusion surgery compared to presurgery levels and healthy controls. Approximately 70% of the patients exhibited elevated blood levels of chromium and titanium.

Serum and tissue metallome of pancreatic ductal adenocarcinoma.

Pancreatic ductal adenocarcinoma (PDAC) patients have late presentation at the time of diagnosis and a poor prognosis. Metal dyshomeostasis is known to play a role in cancer progression. However, the blood and tissue metallome of PDAC patients has not been assessed. This study aimed to determine the levels of essential and toxic metals in the serum and pancreatic tissue from PDAC patients. Serum samples were obtained from PDAC patients before surgical resection. Tissue (tumor and adjacent normal pancreas) were obtained from the surgically resected specimen. Inductively coupled plasma-mass spectrometry (ICP-MS) analysis was performed to quantify the levels of 10 essential and 3 toxic metals in these samples. Statistical analysis was performed to identify dysregulated metals in PDAC and their role as potential diagnostic and prognostic biomarkers. Significantly decreased serum levels of magnesium, potassium, calcium, iron, zinc, selenium, arsenic, and mercury and increased levels of molybdenum were shown to be associated with PDAC. There were significantly decreased levels of zinc, manganese and molybdenum, and increased levels of calcium and selenium in the pancreatic tumor tissue compared with the adjacent normal pancreas. Notably, lower serum levels of calcium, iron, and selenium, and higher levels of manganese, were significantly associated with a poor prognosis (i.e., overall survival) in PDAC patients. In conclusion, this is the first study to comprehensively assess the serum and tissue metallome of PDAC patients. It identified the association of metals with PDAC diagnosis and prognosis.

Food groups consumption and urinary metal mixtures in women from Northern Mexico.

OBJECTIVE: We aimed to evaluate the association between food groups and mixtures of urinary metal concentrations in a sample of women; as well as identify the most important metals within each mixture. METHODS: This is a cross-sectional analysis between food groups consumption and mixtures of various metals in urine from 439 women, ≥18 years old, from Northen Mexico. We estimated the dietary intake of 20 food groups through a validated semi-quantitative food frequency questionnaire. Urinary metal concentration of aluminum, antimony, arsenic, barium, cadmium, cesium, chromium, cobalt, copper, lead, manganese, magnesium, molybdenum, nickel, selenium, thallium, tin, vanadium, and zinc, were measured by inductively coupled plasma triple quad. We used weighted quantile sum (WQS) regression with binomial family specification to assess the association of food groups and metal mixtures, as well as to identify the most important ones. RESULTS: We identified tin, lead, and antimony as the most important metals, in the metal mixtures that were positively associated with the consumption of eggs, non-starchy vegetables, fruits, seafood, corn, oil seeds, chicken, soda, legumes, red and/or processed meats, as well as negatively with the consumption of alliums, corn tortillas and/or vegetable oils. CONCLUSION: Our findings suggest that food consumption is related to more than one metal in the study sample, and highlights the presence of some of them. Further research is required to identify the possible sources of metals in food, as well as the chronic adverse health effects attributed to their simultaneous presence.

Reduction of haemoglobin is related to metal mixtures exposure in Chinese preschoolers: Joint effect models.

Heavy metal exposure is a known risk factor for hematologic disorders in children, yet the impact of co-exposure to multiple metals remains underexplored. This cross-sectional study investigates the relationship between urinary levels of 23 metals and haemoglobin (Hb) in 1460 Chinese preschoolers. The concentrations of the 23 urinary metals were quantified using an inductively coupled plasma mass spectrometer, while Hb levels were assessed through finger prick blood samples. To evaluate the co-exposure effects, we employed three approaches: Generalized linear regression model, joint effect models including Quantile g-Computation and Bayesian Kernel Machine Regression (BKMR). From the generalized linear regression and Quantile g-computation, urinary uranium, thallium, aluminium, iron and tungsten were correlated negatively with Hb, while urinary barium was correlated positively (all P < 0.05). Moreover, significant negative associations between metal mixtures exposure with Hb were identified in both Quantile g-computation [ß (95% CI): -0.083 (-0.132, -0.033), P = 0.0012] and BKMR [90th percentile vs. 50th percentile ß (95% CI): -0.238 (-0.368, -0.107), P < 0.001] with aluminium emerging as the primary contributor to this joint effect (weight in Quantile g-computation = 0.399, PIPs in BKMR = 0.896). These findings provide a potential explanation for environmental exposure to metals and Hb-related disease in preschoolers.

Prospective findings from the Dongfeng-Tongji cohort: Exposure to various metals, the expression of microRNA-4286, and the incidence of acute coronary syndrome.

Mounting evidence suggests that metal/metalloid exposure is related to the adverse health effects. Our prior investigation revealed a positive relation between the plasma level of microRNA-4286 (miR-4286) and an increased risk of developing acute coronary syndrome (ACS). However, it is a lack of studies evaluating the connection between metal/metalloid exposure and miRNA expression on ACS. In the prospective Dongfeng-Tongji cohort, we performed a nested case-control study. A total of 480 ACS and 480 controls were carefully selected based on similar age, sex, and blood collection time. Using inductively coupled plasma mass spectrometry, we assessed the plasma concentrations of 24 different metals. Quantitative real-time polymerase chain reaction was used to analyze the plasma miR-4286. We examined the relations of plasma metals with miR-4286 levels, the incidence of ACS, and the potential interactions. Using the multivariate conditional logistic regression models, we observed that the adjusted odds ratios (95% confidence intervals [CI]) for incident ACS were 1.79 (1.03, 3.12; P-trend = 0.03), 0.60 (0.41, 0.87; P-trend = 0.008), and 0.66 (0.46, 0.93; P-trend = 0.02), when comparing the extreme tertiles of aluminum, rubidium, and selenium, respectively. There was a relation between the concentration of rubidium in plasma and a decrease in the level of plasma miR-4286 (percent difference [95% CI]: -13.36% [-22.74%, -2.83%]; P-trend = 0.01). Both multiplicative (P interaction = 0.009) and additive interactions (relative excess risk due to interaction [95% CI]: 0.82 [0.59, 1.06]) were noted in our observation regarding the relationship between plasma aluminum and miR-4286 in incident ACS. The findings indicated that plasma aluminum was positively while plasma rubidium and selenium were negatively linked to an increased risk of developing ACS. Plasma aluminum exposure and plasma miR-4286 expression might synergistically affect the incident ACS risk. Controlling aluminum exposure was important for ACS prevention, especially for individuals with high expression of plasma miR-4286.

Infant Feeding Practices and Metal Concentrations in Children's Blood.

This cohort study assesses the association between 4 infant feeding practices and concentrations of 8 nonessential and 7 essential metals in red blood cells.

The effect of mask fit test on the association between the concentration of metals in biological samples and the results of time-weighted average personal exposure: A study on Japanese male welders.

OBJECTIVES: The mask fit test confirms whether the wearing condition of the wearer's face and the facepiece of the respirators are used appropriately. This study aimed to examine whether the results of the mask fit test affect the association between the concentration of metals related to welding fumes in biological samples and the results of time-weighted average (TWA) personal exposures. METHODS: A total of 94 male welders were recruited. Blood and urine samples were obtained from all participants to measure the metal exposure levels. Using personal exposure measurements, the 8-h TWA (8 h-TWA) of respirable dust, TWA of respirable Mn, and 8-h TWA of respirable Mn were calculated. The mask fit test was performed using the quantitative method specified in the Japanese Industrial Standard T8150:2021. RESULTS: Fifty-four participants (57%) passed the mask fit test. Only in the Fail group of the mask fit test, it was observed that blood Mn concentrations be positively associated with the results of TWA personal exposure after adjusting for multivariate factors (8-h TWA of respirable dust; coefficient, 0.066; standard error (SE), 0.028; P = 0.018, TWA of respirable Mn: coefficient, 0.048; SE, 0.020; P = 0.019, 8 h-TWA of respirable Mn: coefficient, 0.041; SE, 0.020; P = 0.041). CONCLUSIONS: The results clarify that welders with high concentrations of welding fumes in their breathing air zone are exposed to dust and Mn if there is leaking air owing to the lack of fitness between respirators and the wearer's face when using human samples in Japan.