A longitudinal study of rural Bangladeshi children with long-term arsenic and cadmium exposures and biomarkers of cardiometabolic diseases

Physical activity modified association of urinary metals mixture and fasting blood glucose in children: From two panel studies

There is unclear evidence available on the associations between multiple metals and fasting blood glucose (FBG) in children, and whether they could be beneficial from physical activity. We included 283 children aged 4-12 years from two panel studies with 4-consecutive morning urinary 13 essential metals and 10 non-essential metals repeated across 3 seasons. We employed multiple informant model, linear mixed-effect model, and quantile g-computation to evaluate associations of single metal and their mixture with FBG and interactions with extra-school activity. The results showed that positive relations of multiple essential metals (aluminum, chromium, copper, iron, molybdenum (Mo), nickel, selenium (Se), strontium, zinc) and non-essential metals (arsenic (As), cadmium (Cd), rubidium, titanium (Ti), thallium) with FBG were the strongest at lag 0 (the health examination day), especially in overweight & obesity children (FDR <0.05). The strongest effect presented 1-fold increment in As was related to FBG increased 1.66% (95%CI: 0.84%, 2.48%) in overweight & obesity children. Notably, modification of extra-school activity showed significant, and the effects of multiple metals on FBG were attenuated in children taking total extra-school activity ≥1 h/day, and only one type of which, low or moderate & high intensity extra-school activity reached 20 min/day (Pint <0.05). For instance, each 1-fold increased As was associated with 1.41% increased FBG in overall children taking total extra-school activity <1 h/day, while that of 0.13% in those ≥1 h/day. Meanwhile, mixture of all, essential and non-essential metals were associated with increased FBG, a trend that decreased and became nonsignificant in children having certain extra-school activity, which were dominated by Mo, Se, Ti, Cd. And such relations were substantially beneficial from extra-school activity in overweight & obesity children. Accordingly, multiple essential and non-essential metals, both individual and in mixture, were positively related to FBG in children, which might be attenuated by regular physical activity.

Fetal femur length and risk of diabetes in adolescence: a prospective cohort study

BACKGROUND

Diabetes is more apparent in adulthood but may be dormant in childhood and originates during early fetal development. In fetal biometry, femur length (FL) is crucial for assessing fetal growth and development. This study aimed to assess potential associations between fetal femur growth and prediabetic biomarkers in Bangladeshi children.

METHODS

A cohort study embedded in a population-based maternal food and micronutrient supplementation (MINIMat) trial was conducted in Matlab, Bangladesh. The children in the cohort were followed up until 15 years of age. In the original trial, pregnancy was confirmed by ultrasound before 13 gestational weeks (GWs). Afterward, ultrasound assessments were performed at 14, 19, and 30 GWs. FL was measured from one end to the other, capturing a complete femoral image. The FL was standardized by GW, and a z-score was calculated. FBG and HbA1c levels were determined in plasma and whole blood, and the triglyceride-glucose index, a biomarker of insulin resistance, was calculated as Ln [fasting triglycerides (mg/dl) × fasting glucose (mg/dl)/2]. Multivariable linear regression analysis using a generalized linear model was performed to estimate the effects of FL at 14, 19 and 30 GWs on prediabetic biomarkers at 9 and 15 years of age. Maternal micronutrient and food supplementation group, parity, child sex, and BMI at 9 years or 15 years were included as covariates.

RESULTS

A total of 1.2% (6/515) of the participants had impaired fasting glucose during preadolescence, which increased to 3.5% (15/433) during adolescence. At 9 years, 6.3% (32/508) of the participants had elevated HbA1c%, which increased to 28% (120/431) at 15 years. Additionally, the TyG index increased from 9.5% (49/515) (during preadolescence) to 13% (56/433) (during adolescence). A one standard deviation decrease in FL at 14 and 19 GWs was associated with increased FBG (β = - 0.44 [- 0.88, - 0.004], P = 0.048; β = - 0.59 [- 1.12, - 0.05], P = 0.031) and HbA1c (β = - 0.01; [- 0.03, -0.005], P = 0.007; β = - 0.01 [- 0.03, - 0.003], P = 0.018) levels at 15 years. FL was not associated with diabetic biomarkers at 9 years.

CONCLUSION

Mid-trimester impaired femur growth may be associated with elevated prediabetic biomarkers in Bangladeshi adolescents.

Epigenome-wide perspective of cadmium-associated DNA methylation and its mediation role in the associations of cadmium with lipid levels and dyslipidemia risk

BACKGROUND

Studies demonstrated the associations of cadmium (Cd) with lipid levels and dyslipidemia risk, but the mechanisms involved need further exploration.

OBJECTIVES

We aimed to explore the role of DNA methylation (DNAM) in the relationship of Cd with lipid levels and dyslipidemia risk.

METHODS

Urinary cadmium levels (UCd) were measured by inductively coupled plasma mass spectrometry, serum high-density lipoprotein (HDL), total cholesterol, triglyceride, and low-density lipoprotein were measured with kits, and DNAM was measured using the Infinium MethylationEPIC BeadChip. Robust linear regressions were conducted for epigenome-wide association study. Multivariate linear and logistic regressions were performed to explore the associations of UCd with lipid levels and dyslipidemia risk, respectively. Mediation analyses were conducted to explore potential mediating role of DNAM in the associations of Cd with lipid levels and dyslipidemia risk.

RESULTS

UCd was negatively associated with HDL levels (p = 0.01) and positively associated with dyslipidemia (p < 0.01). There were 92/11 DMPs/DMRs (FDR<0.05) associated with UCd. Cd-associated DNAM and pathways were connected with cardiometabolic diseases and immunity. Cg07829377 (LINC01060) mediated 42.05%/22.88% of the UCd-HDL/UCd-dyslipidemia associations (p = 0.02 and 0.01, respectively).

CONCLUSIONS

Cadmium caused site-specific DNAM alterations and the associations of UCd with lipid levels and dyslipidemia risk may be partially mediated by DNAM.

Cadmium facilitates the formation of large lipid droplets via PLCβ2-DAG-DGKε-PA signal pathway in Leydig cells

Cadmium (Cd) exposure damages the reproductive system. Lipid droplets (LDs) play an important role in steroid-producing cells to provide raw material for steroid hormone. We have found that the LDs of Leydig cells exposed to Cd are bigger than those of normal cells, but the effects on steroidogenesis and its underlying mechanism remains unclear. Using Isobaric tag for relative and absolute quantitation (iTARQ) proteomics, phosphodiesterase beta-2 (PLCβ2) was identified as the most significantly up-regulated protein in immature Leydig cells (ILCs) and adult Leydig cells (ALCs) derived from male rats exposed to maternal Cd. Consistent with high expression of PLCβ2, the size of LDs was increased in Leydig cells exposed to Cd, accompanied by reduction in cholesterol and progesterone (P4) levels. However, the high PLCβ2 did not result in high diacylglycerol (DAG) level, because Cd exposure up-regulated diacylglycerol kinases ε (DGKε) to promote the conversion from DAG to phosphatidic acid (PA). Exogenous PA, which was consistent with the intracellular PA concentration induced by Cd, facilitated the formation of large LDs in R2C cells, followed by reduced P4 level in the culture medium. When PLCβ2 expression was knocked down, the increased DGKε caused by Cd was reversed, and then the PA level was decreased to normal. As results, large LDs returned to normal size, and the level of total cholesterol was improved to restore steroidogenesis. The accumulation of PA regulated by PLCβ2-DAG-DGKε signal pathway is responsible for the formation of large LDs and insufficient steroid hormone synthesis in Leydig cells exposed to Cd. These data highlight that LD is an important target organelle for Cd-induced steroid hormone deficiency in males.

Environmental and occupational exposure to cadmium associated with male reproductive health risk: a systematic review and meta-analysis based on epidemiological evidence

There is an abundance of epidemiological evidence and animal experiments concerning the correlation between cadmium exposure and adverse male reproductive health outcomes. However, the evidence remains inconclusive. We conducted a literature search from PubMed, Embase, and Web of Science over the past 3 decades. Pooled r and 95% confidence intervals (CIs) were derived from Cd levels of the type of biological materials and different outcome indicators to address the large heterogeneity of existing literature. Cd was negatively correlated with semen parameters (r = - 0.122, 95% CI - 0.151 to - 0.092) and positively correlated with sera sex hormones (r = 0.104, 95% CI 0.060 to 0.147). Among them, Cd in three different biological materials (blood, semen, and urine) was negatively correlated with semen parameters, while among sex hormones, only blood and urine were statistically positively correlated. In subgroup analysis, blood Cd was negatively correlated with semen density, sperm motility, sperm morphology, and sperm count. Semen Cd was negatively correlated with semen concentration. As for serum sex hormones, blood Cd had no statistical significance with three hormones, while semen Cd was negatively correlated with testosterone. In summary, cadmium exposure might be associated with the risk of a decline in sperm quality and abnormal levels of sex hormones.

Unraveling the roles of microporous and micro-mesoporous structures of carbon supports on iron oxide properties and As (V) removal performance in contaminated water

This study investigates the impact of microporous (SP-C) and micro-mesoporous carbon (DP-C) supports on the dispersion and phase transformation of iron oxides and their arsenic (V) removal efficiency. The research demonstrates that carbon-supported iron oxide sorbents exhibit superior As(V) uptake capacity compared to unsupported Fe2O3, attributed to reduced iron oxide crystallite sizes and As(V) adsorption on carbon supports. Maximum As(V) uptake capacities of 23.8 mg/g and 18.9 mg/g were achieved for Fe/SP-C and Fe/DP-C at 30 wt% and 50 wt% iron loading, respectively. The study reveals a nonlinear relationship between As(V) sorption capacity and iron oxide crystallite size after excluding As(V) adsorption capacity on carbon supports, suggesting the iron oxide phase (Fe3O4) plays a role in determining adsorption capacity. Iron oxide-loaded DP-C sorbents exhibit faster adsorption rates at low As(V) concentrations (5 mg/L) than SP-C sorbents due to their bimodal pore structure. Adsorption behavior varies at higher As(V) concentrations (45 mg/L), with Fe/DP-C reaching maximum capacity more slowly due to limited available adsorptive sites. All adsorbents maintained near-complete As(V) removal efficiency over five cycles. The findings provide insights for designing more efficient adsorbents for As(V) removal from contaminated water sources.

Cadmium exposure promotes ferroptosis by upregulating Heat Shock Protein 70 in vascular endothelial damage of zebrafish

Cadmium (Cd) exposure is a risk factor for endothelial dysfunction and cardiovascular disease. Ferroptosis is a type of cell death that relies on lipid peroxidation. Whether ferroptosis acts in Cd-induced vascular endothelial damage and the underlying mechanisms remain unclear. Herein, we found that Cd resulted in ferroptosis of vascular endothelial cells (ECs) in vivo and in vitro. In the visualized zebrafish embryos, Cd accumulated in vascular ECs, ROS and lipid peroxidation levels were increased, and the oxidoreductase system was disturbed after exposure. Moreover, Cd decreased Gpx4 in ECs and caused smaller mitochondria with increased membrane density. Accompanied by ferroptosis, the number of ECs and the area of the caudal venous plexus in zebrafish embryos were reduced, and the survival rate of HUVECs decreased. These effects were partially reversed by ferrostatin-1 and aggravated by erastin. Mechanistically, an excessive increase in Heat Shock Protein 70 (Hsp70) was identified by transcriptomics after Cd exposure. Inhibition of Hsp70 by VER-155008 or siRNA ameliorated Cd-induced ferroptosis, thereby alleviating endothelial injury. Furthermore, Hsp70 regulated Cd-induced ferroptosis by targeting multiple targets, including Gpx4, Fth1, Nrf2 and Acsl4. Our findings provide a new approach to investigating the endothelial damage of Cd and indicate that regulation of Hsp70 is an important target for alleviating this process.

Cadmium influence on lipid metabolism in Sprague-Dawley rats through linoleic acid and glycerophospholipid metabolism pathways

Cadmium (Cd) is widely distributed in the environment and easy adsorbed by living organisms with adverse effects. Exposure to Cd-contaminated food may disrupt lipid metabolism and increase human health risk. To study the perturbation effect of Cd on lipid metabolism in vivo, 24 male Sprague-Dawley (SD) rats were randomly assigned four groups and treated by Cd chloride solution (0, 1.375 mg/kg, 5.5 mg/kg, 22 mg/kg) for 14 days. The characteristic indexes of serum lipid metabolism were analyzed. Afterwards, untargeted metabolomics analysis was applied to explore the adverse effects of Cd on rats by liquid chromatography coupled with mass spectrometry (LC-MS). The results revealed that Cd exposure obviously decreased the average serum of triglycerides (TG) and low-density lipoprotein cholesterol (LDL-C) and caused an imbalance of endogenous compounds in the 22 mg/kg Cd-exposed group. Compared with the control group, 30 metabolites with significant differences were identified in the serum. Our results indicated that Cd caused lipid metabolic disorders in rats by disrupting linoleic acid and glycerophospholipid metabolism pathways. Furthermore, there were three kinds of remarkable differential metabolites-9Z,12Z-octadecadienoic acid, PC(20:4(8Z,11Z,14Z,17Z)/0:0), and PC(15:0/18:2(9Z,12Z)), which enriched the two significant metabolism pathways and could be the potential biomarkers.

Elevated serum lead and cadmium levels associated with increased risk of dyslipidemia in children aged 6 to 9 years in Shenzhen, China

Exposure to heavy metals can influence on metabolism, but studies have not fully evaluated young children. We investigated the association between levels of serum lead (Pb), cadmium (Cd), chromium (Cr), and arsenic (As) and risk of dyslipidemia in children. A total of 4513 children aged 6 to 9 years at 19 primary schools in Shenzhen were enrolled. Overall, 663 children with dyslipidemia were matched 1:1 with control by sex and age, and levels of serum Pb, Cd, Cr, and As were detected by inductively coupled plasma-mass spectrometry. Demographic characteristics and lifestyle were covariates in the logistic regression to determine the association of heavy metal levels with risk of dyslipidemia. Serum Pb and Cd levels were significantly higher in children with dyslipidemia than controls (133.08 vs. 84.19 μg/L; 0.45 vs. 0.29 μg/L; all P < 0.05), but this association was not found in Cr and As. We found significant upward trends for the odds ratios (ORs) of dyslipidemia associated with increasing quartiles of Pb and Cd levels (highest quartile of serum Pb OR 1.86, 95% confidence interval (CI) 1.46-2.38; Cd OR 2.51, 95% CI 1.94-3.24). Elevated serum Pb and Cd levels were associated with increased risk of dyslipidemia among children.

Long-term cadmium exposure impairs cognitive function by activating lnc-Gm10532/m6A/FIS1 axis-mediated mitochondrial fission and dysfunction

Cadmium (Cd), a ubiquitous environmental contaminant, is deemed a possible aetiological cause of cognitive disorders in humans. Nevertheless, the exact mechanism by which chronic exposure to Cd causes neurotoxicity is not fully understood. In this study, mouse neuroblastoma cells (Neuro-2a cells) and primary hippocampal neurons were exposed to low-dose (1, 2, and 4 μM for Neuro-2a cells or 0.5, 1, and 1.5 μM for hippocampal neurons) cadmium chloride (CdCl₂) for 72 h (h), and male mice (C57BL/6J, 8 weeks) were orally administered CdCl₂ (0.6 mg/L, approximately equal to 2.58 μg/kg·bw/d) for 6 months to investigate the effects and mechanism of chronic Cd-induced neurotoxicity. Here, chronic exposure to Cd impaired mitochondrial function by promoting excess reactive oxygen species (ROS) production, altering mitochondrial membrane potential (Δψm) and reducing adenosine triphosphate (ATP) content, contributing to neuronal cell death. Specifically, microarray analysis revealed that the long noncoding RNA Gm10532 (lnc-Gm10532) was most highly expressed in Neuro-2a cells exposed to 4 μM CdCl₂ for 72 h compared with controls, and inhibition of lnc-Gm10532 significantly antagonized CdCl₂-induced mitochondrial dysfunction and neurotoxicity. Mechanistically, lnc-Gm10532 increased Fission 1 (FIS1) expression and mitochondrial fission by recruiting the m6A writer methyltransferase-like 14 (METTL14) and enhancing m6A modification of Fis1 mRNA. Moreover, lnc-Gm10532 was also required for chronic Cd-induced mitochondrial dysfunction and memory deficits in a rodent model. Therefore, data of this study reveal a new epigenetic mechanism of chronic Cd neurotoxicity.

A 30-year follow-up study in a former cadmium-polluted area of Japan: the relationship between cadmium exposure and β2-microglobulin in the urine of Japanese people

Cadmium (Cd) is an environmental pollutant. Long-term exposure to Cd may lead to adverse health effects in humans. Our epidemiological studies showed that urinary Cd (U-Cd) concentrations increased from 2008 through 2014, although they decreased from 1986 through 2008. The aim of this study was to elucidate the long-term effects of the changing trend of cadmium exposure levels (U-Cd) on residents' renal function within 30 years after Cd exposure ceased. In 2016, urine samples were collected from each subject by visiting 20 elderly Japanese people (9 females and 11 males) living in the Kakehashi River basin, a previously Cd-polluted area in Ishikawa, Japan. The geometric means of the β₂-microglobulin (β₂-MG) and urinary Cd (U-Cd) continued to increase from 2014 until 2016. Furthermore, Cd concentration and β₂-MG in urine were still higher than those in the non-polluted areas in Japan. Multivariate linear regression was performed to associate β₂-MG (dependent variable) and U-Cd with sex and age (independent variables). Significant correlations were found among age, U-Cd, and β₂-MG, and these were clearer in females than in males. In summary, we propose that three decades after Cd exposure ceased, age is associated with β₂-MG more strongly than Cd for bodily impact. Moreover, renal tubular dysfunction is irreversible and worsens after exposure to Cd, with females being more sensitive to exposure.

Arsenic immobilization in soil affected by mining waste using waste-derived functional hydrochar and iron-encapsulated materials

Arsenic (As) contamination is a widespread problem. Continued and concerted effort in exploring sustainable remediation strategies is required, with in situ immobilization emerging as a promising option. This work valorized a waste by-product from olive (Olea europaea L.) milling into functional hydrochar (HC). The HC was then transformed into iron oxide-encapsulated carbon with three different iron loading rates (10, 25, and 50% w/w of iron chloride hexahydrate added to the olive mill waste feedstock). The HC and the three iron oxide-encapsulated carbon materials were then tested in a pot trial using a 3% w/w application rate as a means to immobilize As in a mining-contaminated soil (2,580 ± 110 mg kg^-1 As). After a 45-d incubation period, the effect of adding the amendments on As mobility and bioaccessibility compared with an untreated control was measured using a sequential extraction procedure and in vitro bioaccessibility, respectively. All four treatments resulted in a decrease in mobility and in vitro bioaccessibility as compared with the control. Specifically, As in the mobile phases was up to 35% less than the in control, whereas bioaccessibility was 21.8% in the control and ranged from 17.5 to 12.3% in the treatments. The efficiency of amendments to immobilize As increased with the iron content of the developed materials. This work positions HCs and iron oxide-encapsulated carbon materials produced from olive mill waste as promising options to immobilize As in situ.

Association between plasma cadmium and renal stone prevalence in adults in rural areas of Guangxi, China: a case-control study

Background

Kidney stones have become a worldwide public health problem. The purpose of this research is to study the relationship between plasma cadmium level and the prevalence of kidney stones in an adult population.

Methods

The data of this study were based on a current survey conducted from December 2018 to November 2019 in Gongcheng Yao Autonomous County, Guangxi, China. A total of 940 study subjects of the same sex and age (within 2 years of each other) according to 1:1 matching were selected for a case–control study. The diagnosis of kidney stones was based on the presence of strong light spots, patches, clusters, or bands within the renal sinus region, followed by an echo-free bundle of acoustic images. Plasma metal elements were determined by the metal plasma method. The relationship between plasma cadmium concentration and the prevalence of kidney stones was assessed using logistic regression and restricted cubic spline regression.

Results

The crude ratio for kidney stones in the highest quartile of plasma cadmium was 1.164 (95% CI, 1.121 to 2.324) compared with the lowest quartile. A positive correlation was found between the two (P for trend = 0.039). After adjusting for potential confounders, the ratio of plasma cadmium to kidney stones in the highest quartile was 1.606 (95% CI, 1.100 to 2.344) compared with the lowest quartile, and the findings remained unchanged.

Conclusion

The odds of kidney stones in adults increased with increasing plasma cadmium exposure, and high plasma cadmium may be a risk factor for kidney stones.

Co-exposure to priority-controlled metals mixture and blood pressure in Chinese children from two panel studies

Metals may affect adversely cardiovascular system, but epidemiological evidence on the associations of priority-controlled metals including antimony (Sb), arsenic (As), cadmium, lead, and thallium with children's blood pressure (BP) was scarce and inconsistent. We conducted two panel studies with 3 surveys across 3 seasons among 144 and 142 children aged 4-12 years in Guangzhou and Weinan, respectively. During each seasonal survey, urine samples were collected for 4 consecutive days and BP was measured on the 4th day. We obtained 786 BP values and urinary metals measurements at least once within 4 days, while 773, 596, 612, and 754 urinary metals measurements were effective on the health examination day (Lag 0), and the 1^st, 2^nd, and 3^rd day preceding BP measurement (Lag 1, lag 2 and lag 3), respectively. We used linear mixed-effect models, generalized estimating equations and multiple informant models to assess the associations of individual metal at each lag day and accumulated lag day (4 days averaged, lag 0-3) with BP and hypertension, and Bayesian Kernel Machine Regression to evaluate the relations of metals mixture at lag 0-3 and BP outcomes. We found Sb was positively and consistently related to systolic BP (SBP), mean arterial pressure (MAP), and odds of having hypertension within 4 days, which were the strongest at lag 0 and declined over time. And such relationships at lag 0-3 showed in a dose-response manner. Meanwhile, Sb was the only contributor to the relations of mixture with SBP, MAP, and odds of having hypertension. Also, synergistic interaction between Sb and As was significant. In addition, modification effect of passive smoking status on the association of Sb and SBP was more evident in passive smokers. Accordingly, urinary Sb was consistently and dose-responsively associated with increased BP and hypertension, of which Sb was the major contributor among children.

Urinary metals as influencing factors of coronary heart disease among a population in Guangzhou, China

The cardiovascular system is highly sensitive to toxic metal exposure and trace element dysregulation. However, previous findings relating to metal exposure and coronary heart disease (CHD) have partially been conflicting and difficult to exhibit the combined effect of metal mixtures. This case-control study investigated urinary concentrations of ten metal/metalloids among clinically-diagnosed CHD patients and healthy adults during May to December 2021 in Guangzhou, China. We found that cadmium (Cd) status in urine from CHD patients was remarkably higher than its reference, while chromium (Cr), nickel (Ni), copper (Cu) and selenium (Se) concentrations were lower (p < 0.05). Spearman correlation analysis showed that urinary arsenic (As) and Se were highly correlated (r_s=0.830, p < 0.001), indicating their similar sources. Principal component analysis (PCA) exhibited denser distribution of Cd-Sn in cases than in controls. Logistic regression analysis exhibited significant associations between urinary Cd (adjusted OR: 1.965, 95% CI: 1.222-3.162), Se (0.787, 95% CI: 0.695-0.893), Ni (0.493, 95% CI: 0.265-0.916) and CHD risk. Quantile g-computation showed negative joint effect of metal mixtures on CHD (adjusted OR: 0.383, 95% CI: 0.159-0.932) (p < 0.05), suggesting the need for supplementing essential trace elements. The negative partial effect was primarily attributed to Se and Ni, while positive partial effect was mainly due to tin (Sn) and Cd. Nevertheless, we also found a quantile increase of Cd-Sn level was negatively correlated with 8.26% (95% CI: 3.44-13.08%) decrease of high-density lipoprotein cholesterol (p < 0.001), and 71.2% of the joint effect attributed to Cd. Based on random forest, Se, Cd and Ni were found to be the dominant influencing factors of CHD. The role of Ni in CHD is yet to be uncovered, while excessive Cd exposure and low Se status among CHD patients need to be mitigated.

Associations between toxic elements and blood pressure parameters in adolescents

BACKGROUND

Both exposure to toxic elements and hypertension (HT) are a global health problem. We planned to examine the associations between some toxic elements in urine, and blood pressure (BP) and its diurnal changes in adolescents.

METHODS

In this cross-sectional study, 48 adolescents who were newly diagnosed with HT and 38 adolescents with age-appropriate BP and normal physical examination were included. Anthropometric measurements, urinary toxic elements, carotid intima media thickness (cIMT), and office and 24-hour ambulatory BP measurements (ABPM) of participants were taken. Urinary elements levels were studied with ICP-MS. Elements were grouped in tertiles according to urinary levels. Logistic regression analyses were performed to show the interactions.

RESULTS

Urinary cadmium, mercury, lead, and arsenic were found to be at detectable level in 90.7%, 69.8%, 91.9% and 100% of the participants, respectively. Univariate analyses showed that elevated daytime systolic and/or diastolic BP was associated with urinary cadmium and mercury. No association between urinary toxic elements and nighttime BP was found. When height and body mass index z-scores adjusted for, age, gender, and all four urinary creatinine-corrected toxic elements analyzed, multiple logistic regression revealed that there was an association between mercury (high vs. low; AOR:3.85) and office HT, and mercury (high vs. low; AOR:6.18) and cadmium (middle vs. low; AOR: 13.38) were associated with "elevated 24-hour systolic BP and/or diastolic BP", and "elevated 24-hour mean arterial BP" in ABPM.

CONCLUSION

There are complex relationships between toxic elements and BP parameters in adolescents, and more studies are needed to define the evolution of these relations.

Associations of total urinary arsenic with total cholesterol and high-density lipoprotein among 12-17-year-old participants from the 2009-2016 NHANES cycles: A cross-sectional study

INTRODUCTION

Hypertension and diabetes are highly prevalent among US adults. Arsenic exposure is associated with these cardiometabolic morbidities but the relationship between arsenic exposure and cholesterol markers of cardiometabolic disease has not been elucidated, especially at younger ages, when many chronic diseases may initiate. This study examined the association of total urinary arsenic with total cholesterol (TC) and high-density lipoprotein cholesterol (HDL) and explored effect modification by weight status.

METHODS

The study sample consisted of 12-17-year-old participants with complete data from the 2009-2016 National Health and Nutrition Examination Survey cycles. The cross-sectional associations of creatinine-adjusted total urinary arsenic with TC and HDL were assessed using multivariable linear regression models with survey weights. Three models were built, adjusting for varying combinations of age, gender, race/ethnicity, weight status, survey cycle, family income to poverty ratio, reference person education level, arsenobetaine, and dimethylarsinic acid (DMA). Model adjustments for arsenobetaine approximated inorganic arsenic exposure, and further adjustment for DMA approximated unmethylated inorganic arsenic exposure. We also explored weight status (underweight/healthy, overweight, and obese) as a potential effect modifier of these relationships using stratified analyses and interaction tests.

RESULTS

The final analytical sample consisted of 1,177 12-17-year-old participants. After adjusting for covariates and arsenobetaine, creatinine-adjusted arsenic was positively associated with HDL levels (β = 0.063; 95% CI: 0.007, 0.119). Upon further adjustment for DMA, creatinine-adjusted arsenic was positively associated with HDL levels (β = 0.079; 95% CI: 0.015, 0.143) and TC levels (β = 0.258; 95% CI: 0.002, 0.515). No effect modification by weight status was observed.

CONCLUSIONS

We found a positive association of approximated unmethylated inorganic arsenic exposure with TC, and contrary to our expectation, with HDL. There was no effect modification by weight status. Our findings should be confirmed by conducting longitudinal studies among adolescents exposed to low-level arsenic and focusing specifically on urinary inorganic arsenic concentrations.

Heavy metal ion concentration in the amniotic fluid of preterm and term pregnancies from two cities with different industrial output

The growth and development of the fetus is a complex phenomenon that can be influenced by several variables. High quantities of heavy metal ions in the amniotic fluid have been linked to poor health, especially in industrial, polluted and poor areas. The aim of the present study was to assess the differences in the concentration of these ions between preterm (weeks 15-37) and term pregnancies (starting at week 37). Another objective was to compare pregnancies from two cities with different industry levels. Two sample lots from two Romanian cities were analyzed. A total of 100 patients from Timisoara were compared with 60 from Petrosani, a heavy industry city in Romania. Demographic data were collected, and amniocentesis was performed on all women. Lead (Pb), copper (Cu), nickel (Ni), cadmium (Cd), arsenic (As), iron (Fe) and zinc (Zn) concentrations were assessed. Descriptive and analytical statistics were performed using the Mann-Whitney U test for non-parametric data and the Fisher's exact test for categorical data. In addition, categorical data was represented graphically. In the Timisoara cohort, the differences in heavy metal concentrations between preterm and term pregnancies were not statistically significant. In the Petrosani cohort, however, the concentrations of Zn (P=0.02606) and Cd (P=0.01512) were higher in preterm than in term pregnancies. When comparing the two cohorts as a whole, the concentration of Pb (P=0.04513), Cd (P=0.00002), As (P=0.03027) and Zn (P<0.00001) were higher in the patients from Petrosani than in those from Timisoara. Only Cu concentrations were higher in the Timisoara cohort (P<0.00001). The concentrations of Ni (P=0.78150) and Fe (P=0.44540) did not differ statistically. Thus, amniocentesis is an important diagnostic and exploratory tool in determining differences in the concentrations of elements such as heavy metal ions. Research over a longer period of time should be carried out to examine the relation between heavy metal ions concentration and possible postnatal health outcomes.

The interaction between selenium and cadmium in the soil-rice-human continuum in an area with high geological background of selenium and cadmium

Natural selenium (Se)-rich areas in China are generally characterized by high geological background of cadmium (Cd). However, the interaction between Se and Cd in the soil-rice-human continuum in such areas remains elusive. The concentrations, bioaccessibilities, and biomarkers of Se and Cd in a typical Se-Cd rich area were determined through chemical analysis, in vitro digestion model and cross-sectional study, respectively. The results showed that the molar ratio of available Se/Cd in the soil was averaged at 0.55 and soil Se did not reduce Cd accumulation and transportation in rice. Se bioaccessibility increased from the gastric phase to the intestinal phase, but the opposite was the case for Cd bioaccessibility. Moreover, bioaccessible concentration of Cd was positively correlated to corresponding total concentration in rice but negatively associated with the logarithm of molar ratio of Se/Cd. The risk of Cd-induced nephrotoxicity for the exposure group was not higher than the reference group, which could be ascribed to the mitigative effect of Se. Males and elders were at higher risk of Cd-induced injury owing to higher urinary Cd (U-Cd) and β2-microglobulin (U-β2-MG), and lower urinary Se (U-Se). Our results suggested that Cd-induced health risk should be assessed from a soil-rice-human perspective and the interaction between Se and Cd should be taken into account.

Potency of spirulina (Spirulina platensis) on arsenic-induced lipid peroxidation in rat

Objective

Natural substances found in dietary sources and medicinal plants have attracted considerable attention in recent years as chemopreventive agents. Spirulina is a blue-green alga that possesses chemopreventive properties. The purpose of this study was to determine the effect of spirulina on rats with inorganic arsenic (As) [sodium arsenite (NaAsO₂)]-induced lipid peroxidation.

Materials and Methods

120 rats were randomly assigned to 10 groups and designated T0, T1, T2, T3, T4, T5, T6, T7, T8, and T9. One group was kept as a control (T0) that received no treatment. The seven groups received 3.0 mg of NaAsO₂/kg body weight in drinking water and were given spirulina ad libitum. T1 was treated with NaAsO₂ but not with spirulina. Two groups of rats (T2 and T3), on the other hand, were treated with spirulina without receiving any As (NaAsO₂). T2 received agro-based spirulina (Ab-Sp; grown in 1.5% soybean meal media and harvested on day 12 of seed inoculation) at 2.0 gm/kg feed, whereas T3 received commercially available spirulina (Com-Sp) at 2.0 gm/kg feed. T4, T5, and T6 were concurrently treated with Ab-Sp at 1.0, 1.5, and 2.0 gm/kg of feed. On the other hand, T7, T8, and T9 induced by NaAsO₂ were concurrently treated with Com-Sp at 1.0, 1.5, and 2.0 gm/kg feed. All groups received treatment for 90 days.

Results

The efficacy of both spirulina in preventing lipid peroxidation caused by As was determined quantitatively by measuring the rats' serum malondialdehyde (MDA). The results indicated that As supplementation increased serum MDA levels, whereas both types of spirulina significantly decreased them. The highest dose of Ab-Sp (2.0 gm/kg feed) was found to be the most effective in preventing lipid peroxidation in rats treated with inorganic As.

Conclusion

Ab-Sp could be a natural, cost-effective, and safe measure to mitigate As toxicity.