Chronic Kidney Disease and Exposure to Nephrotoxic Metals

Vanadium exposure and kidney markers in a pediatric population: a cross-sectional study

BACKGROUND

Anthropogenic vanadium (V) emissions and exposure in the general population have recently increased. Experimental studies have shown that V is a nephrotoxic agent, but little is known about its effects on human kidney health. This work evaluated the association between urinary V concentrations with early kidney damage biomarkers and function in a pediatric population without any disease diagnosed.

METHODS

A cross-sectional study was carried out and included 914 healthy subjects and determined urinary V concentrations, glomerular filtration rate (eGFR), albumin-creatinine ratio (ACR), and the presence of kidney injury molecule 1 (KIM-1) and neutrophil gelatinase-associated lipocalin (NGAL) in urine. We evaluated the V effect using linear and logistic regression models adjusted by confounders.

RESULTS

Subjects found in the second and third tertiles of V showed an increase in urinary log-NGAL levels (βT2 vs. T1 = 0.39; 95% CI 0.14, 0.64, and βT3 vs. T1 = 1.04; 95% CI 0.75, 1.34) and log-KIM-1(βT2 vs. T1 = 0.25; 95% CI 0.04, 0.45 and βT3 vs. T1 = 0.39; 95% CI 0.15, 0.63); in addition, subjects in the third tertile had a positive and significant association with ACR (ORT3 vs. T1 = 1.96; 95% CI 1.29, 2.97) and increased in eGFR (βT3 vs. T1 = 3.98, 95% CI 0.39, 7.58), compared with subjects in the first tertile.

CONCLUSIONS

Our study reports the effect of V on kidney markers in a healthy pediatric population. It could be related to tubulointerstitial lesions and function abnormalities.

Chlorogenic acid improves urogenital dysfunction induced by exposure to ambient particulate matter

Oxidative stress is a well-known underlying mechanism for several diseases in response to environmental pollution. Although there is a lack of evidence on the relationship between air pollution and an established risk factor for urogenital dysfunction. The aim of this study was to investigate the mechanism of particulate matter (PM) on urogenital function and evaluate the potential efficacy of chlorogenic acid (CGA) in preventing urogenital damage in rats. Forty Wistar rats were divided into five groups (n = 8): control, particulate matter exposure (animals were exposed to fine dust in an inhalation chamber for 4 weeks, 3 days a week, for 3 h, PM10 concentration adjusted to 500-2000 µg/m3), and particulate matter plus 3 concentrations of chlorogenic acid (100, 200, and 400 mg/kg, gavage, 4 weeks, 3 days a week). At the end of the study, kidney biomarkers, oxidative stress markers, antioxidant enzymes, the oxidation resistance 1 (OXR1) and its downstream gene expression, sperm count, gonadotropin hormones, and the structure of the kidney, epididymis, and seminal vesicle were evaluated in response to PM exposure and CGA treatment in all groups. The data obtained from the current study showed that PM exposure led to kidney dysfunction and inhibition of oligospermia through oxidative stress, as evidenced by an increase in MDA and a decrease in TAC, SOD, CAT, and GSH concentration levels in blood samples. These results were consistent with the down-regulation of OXR1, Nrf2, and P21 gene expression. In contrast, CGA improved urogenital biomarkers and histopathology structures of the kidney, epididymis, and seminal vesicle by enhancing antioxidant defense system enzymes and modulating the OXR1 signaling pathway. Our findings suggest that environmental air pollution contributes to kidney dysfunction and urogenital damage. Modulation of oxidative stress through the OXR1, P21, and Nrf2 signaling pathways may be the underlying mechanism. Furthermore, chlorogenic acid supplementation could be recommended as a new protective or treatment strategy to safeguard urogenital function against exposure to particulate matter.

The association between low-concentration heavy metal exposure and chronic kidney disease risk through α-klotho

Although the association between pollution exposure and chronic kidney disease (CKD) has been explored, previous studies have focused on specific effects observed via in vitro or animal experiments. We first conducted a priority screening of pollutants for population CKD risk by using machine learning approaches. We then used the National Health and Nutrition Examination Survey (NHANES) 2007-2016 data from 2415 adults aged 40 years and over to study the joint effects of low-concentration metal exposure and the mediating effects of α-klotho by using Bayesian kernel machine regression (BKMR) and mediation analyses. Priority screening revealed that cadmium (Cd), mercury (Hg), lead (Pb), and thallium (Tl) were associated with the highest risk of developing CKD. The BKMR model revealed a negative joint effect of mixed-metal exposure on CKD risk. Tl presented the highest posterior inclusion probability (PIP) of 1.0000, followed by Pb, with a PIP of 0.6080. Significant mediating effects of α-klotho on Hg-CKD associations were observed. Mendelian randomization demonstrated that a high level of α-klotho is associated with a decreased risk of developing CKD. This is the first study to reveal the risk prioritization of various pollutants in CKD patients, as well as the coexposure effects of metals. Our study also provides insight into the potential mechanisms underlying the association between metal exposure and CKD risk.

Trends and Disparities in the Burden of Chronic Kidney Disease due to Type 2 Diabetes in China From 1990 to 2021: A Population-Based Study

BACKGROUND

This study analyzes the trends in the burden of chronic kidney disease due to type 2 diabetes (CKD-T2D) in China from 1990 to 2021, evaluates variations in risk factors, and projects the disease burden through 2036.

METHOD

Estimates of prevalence, incidence, mortality, and disability-adjusted life years (DALYs) for CKD-T2D were retrieved along with their 95% uncertainty intervals (UIs). Age-period-cohort analysis was used to assess burden trends from 1990 to 2021, identify risk factor population attributable fractions (PAFs), and project the burden through 2036.

RESULTS

In 2021, there were 20 911 520 CKD-T2D cases in China, with an age-standardized prevalence rate (ASPR) of 1053.92 per 100 000, an incidence rate (ASIR) of 23.07, an age-standardized mortality rate (ASMR) of 5.72, and an age-standardized DALY rate (ASDR) of 122.15. Although the overall burden showed a slow decline from 1990 to 2021, incidence continued to rise. The 2021 data revealed a marked age effect, with the burden rising with age. Period effects also contributed to an increased risk, with metabolic risk factors such as high fasting plasma glucose and BMI contributing the most. Projections suggest a decline in mortality and DALYs by 2036, while incidence will keep increasing.

CONCLUSION

Despite declines in ASMR and ASDR, CKD-T2D incidence and cases continue to rise, especially among males and the elderly. This increasing burden is driven by aging and metabolic risk factors. Early screening, education, and risk management are essential for addressing CKD-T2D in China.

Polydatin Mitigates Lead-Induced Nephropathy by Modulating Oxidative Stress, Inflammation, and the AMPK/AKT/Nrf2 Pathway in Rats

This study investigated the molecular mechanisms underlying lead (Pb)-induced nephropathy and assessed the nephroprotective potential of Polydatin (PD). Forty male Wistar rats were divided into five groups (n = 8/group): negative control (NC), normal rats treated with 200 mg/kg/day of PD (NPD200), positive control (PC) receiving Pb only (30 mg/kg/day), and two groups co-administered Pb with PD (100 or 200 mg/kg/day). Serum and urine Pb levels were determined by an atomic absorption spectrophotometer. Markers of renal tissue damage (TGF-β/iNOS/NGLA/KIM-1) and renoprotective molecules (Nrf2/AMKα/AKT1) genes and proteins were measured by quantitative RT-PCR and Immunohistochemistry, respectively. ELISA was used to quantify markers of oxidative stress (GSH/Gpx1/CAT/MDA/H2O2) and inflammation (TNFα/IL1β/IL6/IL-10/IFN-γ). The PC group exhibited significant renal damage, including abnormal histology, increased apoptosis, elevated serum creatinine and urea, proteinuria, and polyuria. The PC renal tissues also showed substantial upregulations of iNOS/TGF-β/KIM-1/NGAL, whilst Nrf2/AMPK/AKT declined compared to healthy rats. Moreover, levels of oxidative stress (MDA/H2O2) and inflammatory (TNF-α/IL1β/IL6) markers were substantially higher in the PC renal specimens, whereas the antioxidants (GSH/GPx/CAT) with IL-10 and IFN-γ decreased than the NC group. Co-administration of PD with Pb improved renal biochemical parameters, attenuated histopathological changes and apoptosis, reduced the expression of iNOS/TGF-β/KIM-1, concentrations of oxidative stress and pro-inflammatory markers, whilst enhanced antioxidants and Nrf2/AMPK/AKT/IL-10/IFN-γ levels. However, the protective effects of the PD high-dose regimen were significantly greater than the low-dose protocol. In conclusion, PD prophylactic regimens mitigated Pb-induced nephrotoxicity by targeting oxidative stress and inflammation, with the high-dose protocol demonstrating superior nephroprotective efficacy.

Associations of Blood and Urinary Heavy Metals with Stress Urinary Incontinence Risk Among Adults in NHANES, 2003-2018

People come into contact with heavy metals in various ways in their daily lives. Accumulating evidence shows that toxic metal exposure is hazardous to human health. However, limited information is available regarding the impact of metal mixtures on stress urinary incontinence (SUI). Therefore, we used data from 10,622 adults from the 2003-2018 National Health and Nutrition Examination Survey (NHANES) to investigate the independent and comprehensive association between heavy metal co-exposure and SUI. Among them, 2455 (23.1%) had been diagnosed with SUI, while the rest had no SUI. We evaluated the independent and combined associations of 3 blood metals and 10 urinary metals with SUI risk, along with subgroup analyses according to age and gender. In the single-exposure model, blood cadmium (Cd), lead (Pb), mercury (Hg), urinary Cd, Pb, and cesium (Cs) were found to be positively connected with SUI risk. Moreover, weighted quantile sum (WQS) regression, quantile-based g-computation (qgcomp), and Bayesian kernel machine regression (BKMR) consistently demonstrated blood and urinary metal-mixed exposure were positively associated with the risk of SUI, and emphasized that blood Pb and Cd and urinary Cd and Cs were the main positive drivers, respectively. This association was more pronounced in the young and middle-aged group (20-59 years old) and the female group. Nevertheless, further research is necessary to validate these significant findings.

Development of diselenide-based fluorogenic system for the selective and sensitive detection of the Hg(II) in aqueous media

Mercury(II) is highly toxic thus the selective and sensitive detection of Hg(II) is important. This research article deals with the synthesis and characterization of the fluorogenic system based on diselenide containing rhodamine by single crystal XRD. The probe has been used for selective detection of Hg(II) in aqueous media with detection limit of 62.3 nM. The reaction of the Hg(II) with the probe induces opening of the spirolactam ring triggering fluorescence turn-on response. This reaction causes color change of the probe solution from colorless to pink. In addition, the probe showed the reversible binding behavior with Hg(II) and S2-. The effectiveness of the probe was evaluated using prostate cancer cell line through live cell imaging.

Advances in kidney disease: pathogenesis and therapeutic targets

Chronic kidney disease (CKD) is a global public health issue characterized by progressive loss of kidney function, of which end-stage kidney disease (ESKD) is the last stage. The global increase in the prevalence of CKD is linked to the increasing prevalence of traditional risk factors, including obesity, hypertension, and diabetes mellitus, as well as metabolic factors, particularly insulin resistance, dyslipidemia, and hyperuricemia. Mortality and comorbidities, such as cardiovascular complications, rise steadily as kidney function deteriorates. Patients who progress to ESKD require long-term kidney replacement therapy, such as transplantation or hemodialysis/peritoneal dialysis. It is currently understood that a crucial aspect of CKD involves persistent, low-grade inflammation. In addition, increased oxidative and metabolic stress, endothelial dysfunction, vascular calcification from poor calcium and phosphate metabolism, and difficulties with coagulation are some of the complex molecular pathways underlying CKD-related and ESKD-related issues. Novel mechanisms, such as microbiome dysbiosis and apolipoprotein L1 gene mutation, have improved our understanding of kidney disease mechanisms. High kidney disease risk of Africa has been linked to APOL1 high-risk alleles. The 3-fold increased risk of ESKD in African Americans compared to European Americans is currently mainly attributed to variants in the APOL1 gene in the chromosome 22q12 locus. Additionally, the role of new therapies such as SGLT2 inhibitors, mineralocorticoid receptor antagonists, and APOL1 channel function inhibitors offers new therapeutic targets in slowing down the progression of chronic kidney disease. This review describes recent molecular mechanisms underlying CKD and emerging therapeutic targets.

The spatiotemporal and paradoxical roles of NRF2 in renal toxicity and kidney diseases

Over 10% of the global population is at risk to kidney disorders. Nuclear factor erythroid-derived 2-related factor 2 (NRF2), a pivotal regulator of redox homeostasis, orchestrates antioxidant response that effectively counters oxidative stress and inflammatory response in a variety of acute pathophysiological conditions, including acute kidney injury (AKI) and early stage of renal toxicity. However, if persistently activated, NRF2-induced transcriptional cascade may disrupt normal cell signaling and contribute to numerous chronic pathogenic processes such as fibrosis. In this concise review, we assembled experimental evidence to reveal the cell- and pathophysiological condition-specific roles of NRF2 in renal chemical toxicity, AKI, and chronic kidney disease (CKD), all of which are closely associated with oxidative stress and inflammation. By incorporating pertinent research findings on NRF2 activators, we dissected the spatiotemporal roles of NRF2 in distinct nephrotoxic settings and kidney diseases. Herein, NRF2 exhibits diverse expression patterns and downstream gene profiles across distinct kidney regions and cell types, and during specific phases of nephropathic progression. These changes are directly or indirectly connected to altered antioxidant defense, damage repair, inflammatory response, regulated cell death and fibrogenesis, culminating ultimately in either protective or deleterious outcomes. The spatiotemporal and paradoxical characteristics of NRF2 in mitigating nephrotoxicity suggest that translational application of NRF2 activation strategy for prevention and interventions of kidney injury are unlikely to be straightforward - right timing and spatial precision must be taken into consideration.

Association between urinary heavy metal/trace element concentrations and kidney function: a prospective study

Background

Chronic kidney disease (CKD) is an important public health problem. Although cross-sectional studies have identified many heavy metals/trace elements associated with reduced kidney function, prospective studies are needed to determine the pathogenic role of these elements in the development and progression of CKD.

Methods

To explore the association between baseline urinary heavy metal/trace element concentrations and long-term impaired kidney function (IKF)/CKD, as well as the incidence of rapid decline in kidney function in a population-based exploratory prospective study, with mean age 51.9 years at baseline whose urinary trace elements concentrations have been determined by inductively coupled plasma mass spectrometry. IKF was defined by a reduced estimated glomerular filtration rate (eGFR) between 60 and 90 mL/min/1.73 m2, and CKD was defined as an eGFR <60 mL/min/1.73 m2. Rapid eGFR decline was defined as a decrease ≥3 mL/min/1.73 m2/year.

Results

Over a mean follow-up of 12.5 years, 123 participants (2.6%) experienced rapid decline in kidney function, and 1455 (31.7%) developed IKF or CKD. After adjusting for covariates including baseline eGFR, we found that urinary vanadium [hazard ratio (HR) = 1.07, 1.03-1.12], cobalt (HR = 1.69, 1.21-2.37), nickel (HR = 1.19, 1.08-1.3), copper (HR = 1.03, 1.01-1.06), selenium (HR = 1.33, 1.02-1.73), molybdenum (HR = 1.48, 1.2-1.82) and iodine (HR = 1.1, 1.02-1.2) were associated with an increased risk of new incident IKF or CKD cases during the follow-up. Also, urinary copper [odds ratio (OR) = 1.12, 1.04-1.21], silver (OR = 1.83, 1-3.35), molybdenum (OR = 1.02, 1.01-1.04) and cadmium (OR = 1.05, 1.01-1.09) were associated with an increased risk of rapid eGFR decline.

Conclusion

In the general population, several urinary heavy metals/trace elements are associated with a rapid decline in kidney function or new cases of IKF/CKD.

Toxicology Effects of Cadmium in Pomacea canaliculate: Accumulation, Oxidative Stress, Microbial Community, and Transcriptome Analysis

Cadmium (Cd) pollution poses an important problem, but limited information is available about the toxicology effects of Cd on freshwater invertebrates. We investigated the accumulation, oxidative stress, microbial community changes, and transcriptomic alterations in apple snails (Pomacea canaliculata) under Cd stress. The snails were exposed to the 10 μg/L Cd solution for 16 days, followed by a 16-day elimination period. Our results showed that the liver accumulated the highest Cd concentration (17.41 μg/g), followed by the kidneys (8.00 μg/g) and intestine-stomach (6.68 μg/g), highlighting these tissues as primary targets for Cd accumulation. During the elimination period, Cd concentrations decreased in all tissues, with the head-foot and shell exhibiting over 30% elimination rates. Cd stress also resulted in reduced activities of superoxide dismutase (SOD), catalase (CAT), and glutathione transferase (GST) compared to the control group. Notably, even after 16 days of depuration, the enzyme activities did not return to normal levels, indicating persistent toxicological effects. Cd exposure significantly reduced the diversity of gut microbiota in P. canaliculata. Moreover, transcriptome analysis identified differentially expressed genes (DEGs) primarily associated with lysosome function, motor proteins, protein processing in the endoplasmic reticulum, drug metabolism via cytochrome P450 (CYP450), arachidonic acid metabolism, and ECM-receptor interactions. These findings suggest that Cd stress predominantly disrupts cellular transport and metabolic processes. Overall, our study provides comprehensive insights into the toxicological impact of Cd on P. canaliculata and emphasizes the importance of understanding the mechanisms underlying Cd toxicity in aquatic organisms.

The association between urinary lead concentration and the likelihood of kidney stones in US adults: a population-based study

The negative effects of lead exposure on human health have attracted widespread attention. Our present study focused on assessing the relationship between urinary lead levels (ULL) and the risk of kidney stones in US adults. We used data from NHANES 2007-2018 for this cross-sectional study, where participants had complete data on ULL and kidney stones. The correlation between ULL and kidney stones was explored by weighted multiple logistic regression analysis. In addition, we also performed subgroup analysis and interaction tests. A total of 8325 subjects were included, and the prevalence of kidney stones was 9.90%. In the fully adjusted model, we observed a positive association between ULL and the risk of kidney stones (OR:1.07, 95% CI: 1.01-1.14, p = 0.03). Participants in the highest quartile of ULL had a 64% higher risk of kidney stones than those in the lowest quartile of ULL (OR:1.64, 95% CI: 1.05-2.57, p = 0.03). Subgroup analysis and interaction test indicated that the association between ULL and the risk of kidney stones was similar in different population settings. The findings of this study indicate a positive correlation between urine lead concentration and the risk of kidney stones. The potential prognostic value of the urine lead concentration for kidney stone outcomes was another new area investigated in this study. However, further prospective clinical trials are needed to confirm the role of urine lead in the pathogenesis of kidney disease and to validate urine lead as a reliable predictor of kidney stone risk.

Sublethal Concentrations of Cadmium and Lead: Effects on Hemato-Biochemical Parameters and Tissue Accumulation in Wallagu attu

The exposure of fish to heavy metals can significantly impact physiological processes and potentially lead to adverse health effects. This study assesses the effects of exposure to Cd and Pb sublethal concentrations in water on Wallagu attu. A total of 48 fish with an average body weight of 145.5 ± 26 g were distributed among three groups (control, Cd-treated, and Pb-treated) within 60 L fiberglass tanks. They were exposed to 30% sublethal concentrations of Cd and Pb for durations of 1, 15, and 30 days. Following this exposure, an assessment was conducted on metal bioaccumulation and hemato-biochemical responses. Results revealed a significantly (P < 0.05) higher concentration of heavy metals in the fish tissues of metals exposed groups than in the control. The concentration of Cd and Pb increases in fish tissues (kidney > gills > intestine) with exposure time. In most cases, the Pb-exposed group exhibited significantly (P < 0.05) higher concentrations of Pb in different tissues than the Cd-treated group. With extended exposure time, the activities of CAT and SOD show a significant decrease in both Cd and Pb-treated groups. However, the reduction in activities was more pronounced in the Cd-exposed group. On 15 and 30 days, the levels of red blood cells (RBC), hemoglobin (HB), hematocrit (HCT), and total protein (TP) decrease in groups exposed to Cd and Pb. The cortisol and glucose levels exhibit a more noticeable (P < 0.05) increase with prolonged exposure to Cd and Pb than the control group. On day 30, the survival rate decreased more in the Pb-exposed group. The findings of this study indicate that exposure to sublethal doses of Cd and Pb induces stress in Wallagu attu, resulting in rapid changes in specific hemato-biochemical parameters.

Coenzyme Q10 Attenuates Kidney Injury Induced by Titanium Dioxide Nanoparticles and Cadmium Co-exposure in Rats

This study examined the possible defensive role of coenzyme Q10 (CQ10) against the impact of cadmium (Cd) and titanium dioxide nanoparticle (TNP) exposure on rat kidneys. Distilled water (1 mL/rat), corn oil (1 mL/rat), 10 mg CQ10/kg b.wt, 50 mg TNP/kg b.wt, 5 mg Cd/kg b.wt, TNP + Cd, or TNP + Cd + CQ10 was administered orally to seven groups of 70 male Sprague Dawley rats for 60 days. The findings demonstrated that TNP and/or Cd exposure considerably raised serum levels of several renal damage products, disturbed electrolyte balance including sodium, potassium, and calcium, decreased antioxidant enzyme concentration in the kidneys, and elevated malondialdehyde. In addition, rats exposed to TNP and/or Cd had significantly higher levels of renal titanium and Cd. In addition, rats exposed to TNP and/or Cd showed significant histopathological lesions and collagen deposition as revealed by H and E and Masson trichrome staining, respectively. The kidneys were severely damaged by the combined effects of TNP and Cd, although CQ10 greatly mitigated these effects. According to the study, exposure to TNP and Cd can damage the kidneys' function and structure, especially when combined. However, CQ10 can protect against TNP and Cd's nephrotoxic effects.

Heavy metal(loid) bioaccumulation in fish and its implications for human health

Heavy metal(loid)s (HM) pollution in aquatic environments is a serious issue due to the toxicity, persistence, bioaccumulation, and biomagnification of these pollutants. The main sources of HM contamination are industrial activities, mining, agricultural practices, and combustion of fossil fuels. Fish can accumulate HMs through a process called bioaccumulation. As larger predatory fish consume smaller fish, these HMs enter the main food chains and can become increasingly concentrated in their tissues and finally reach humans. Here, we provided a general and concise conclusion from current research findings on the toxicological effects on different body systems. Exposure to HMs can lead to a range of adverse health effects, including neurological damage, developmental disorders, kidney damage, cardiovascular problems, and cancers. Their long-term accumulation can result in chronic toxicity even at low levels of exposure. HMs exert cellular cytotoxicity by disrupting essential cellular processes and structures. They can interfere with enzyme function, disrupt cell membrane integrity, induce oxidative stress, and cause DNA damage, ultimately leading to cell death or dysfunction. Prevention and control of HMs involve implementing measures to reduce their release into the environment through regulations on industrial processes, waste management, and pollution control technologies. Additionally, monitoring and remediation efforts are crucial for identifying contaminated sites and implementing strategies such as soil and water remediation to reduce human exposure and mitigate the impact on ecosystems. To conclude, HM accumulation in fish poses serious risks to public health and the environment, necessitating urgent interdisciplinary efforts to mitigate their harmful effects and promote sustainable practices that reduce HM flow into biological systems.

Blood cadmium levels and overactive bladder in middle-aged and older adults in the United States: Insights from NHANES 2007-2020 data

Cadmium is a common environmental pollutant associated with various health risks. Its neurotoxic, muscle-damaging, and pro-inflammatory properties may be related to overactive bladder (OAB), though few studies have assessed its impact on urinary function. This study aimed to examine the potential link between cadmium exposure and OAB. Using data from the 2007-2020 National Health and Nutrition Examination Survey (NHANES), we analyzed adults aged 40 and older (n = 15,467) in a cross-sectional design. OAB was defined by the refined Overactive Bladder Symptom Score (OABSS). Weighted multivariate logistic regression examined the associations between blood cadmium levels and OAB and its components. Age and gender stratifications were performed, and restricted cubic splines (RCS) were used to explore non-linear associations between blood cadmium and OAB. Sensitivity analyses and co-exposure analyses with other pollutants were conducted to assess OAB definition stability, subgroup differences, and exposure collinearity. The prevalence of OAB was 26.2%. While blood cadmium showed a small, non-significant positive association with overall OAB, it was inversely associated with nocturia severity (OR = 0.85, 95% CI 0.74-0.98, p < 0.05). Blood cadmium was also linked to more severe urinary incontinence in the 50-59 age group and among non-Hispanic Black adults. A non-linear association between blood cadmium and OAB was observed (p for nonlinearity = 0.016, p < 0.05). In co-exposure analyses, cadmium remained a dominant and independent factor. These findings suggest that cadmium exposure may have a complex association with OAB and may relate differently to its various components. Further research is needed to explore these relationships.

Relationships between blood concentrations of cadmium, lead, mercury, selenium, and manganese and the risk of chronic kidney disease: a cross-sectional study based on NHANES 2011-2018

Introduction

Currently, knowledge on relationships between blood concentrations of cadmium, lead, mercury, selenium, and manganese and the risk of chronic kidney disease (CKD) is lacking. The aim of the study was to ex-plore the relationships between blood concentrations of heavy metals and the occurrence of CKD.

Material and methods

Data from the National Health and Nutrition Examination Survey (NHANES) 2011-2018 were used to investigate the relationships between blood concentrations of mercury, lead, cadmium, selenium, and manganese and the occurrence of CKD using a weighted logistic recession analysis. Restrictive cubic spline analysis was applied to assess the dose-response relationship. The sample population was divided into four groups based on the quartiles of heavy metal concentrations (Q1: < 25th percentile, Q2: 25th-50th percentile, Q3: 50th-75th percentile, Q4: ≥ 75th percentile).

Results

A total of 15,450 participants were included. With regard to blood lead concentrations, the odds ratio (OR) for CKD in Q4 relative to Q1 was 1.36 (95% confidence interval [CI]: 1.20-1.61), indicating an increased oc-currence of CKD in Q4. With regard to blood cadmium concentrations, the ORs for CKD in Q2, Q3, and Q4 were 1.06 (95% CI: 0.92-1.22), 1.21 (95% CI: 1.05-1.39), and 1.52 (95% CI: 1.31-1.76), respectively. Non-linear dose-response relationships were identified between blood cadmium and lead concentrations and the occurrence of CKD. Further, blood lead and cadmium concentrations showed statistically significant interaction effects with age, hypertension, and obesity on CKD.

Conclusions

Higher cadmium and lead concentrations in blood are asso-ciated with increased occurrence of CKD, especially in older adults, people with hypertension, and people with obesity.

Chronic Kidney Disease of Unknown Etiology: A Global Health Threat in Rural Agricultural Communities-Prevalence, Suspected Causes, Mechanisms, and Prevention Strategies

Chronic Kidney Disease of Unknown Etiology (CKDu) is a worldwide hidden health threat that is associated with progressive loss of kidney functions without showing any initial symptoms until reaching end-stage renal failure, eventually leading to death. It is a growing health problem in Asia, Central America, Africa, and the Middle East, with identified hotspots. CKDu disease mainly affects young men in rural farming communities, while its etiology is not related to hypertension, kidney stones, diabetes, or other known causes. The main suspected causal factors are heat-stress, dehydration, exposure to agrochemicals, heavy metals and use of hard water, infections, mycotoxins, nephrotoxic agents, altitude, and genetic factors. This review gives an overview of CKDu and sheds light on its medical history, geographic distribution, and worldwide prevalence. It also summarizes the suspected causal factors, their proposed mechanisms of action, as well as the main methods used in the CKDu prior detection and surveillance. In addition, mitigation measures to reduce the burden of CKDu are also discussed. Further investigation utilizing more robust study designs would provide a better understanding of the risk factors linked to CKDu and their comparison between affected regions.

Investigating the relationship of co-exposure to multiple metals with chronic kidney disease: An integrated perspective from epidemiology and adverse outcome pathways

Systematic studies on the associations between co-exposure to multiple metals and chronic kidney disease (CKD), as well as the underlying mechanisms, remain insufficient. This study aimed to provide a comprehensive perspective on the risk of CKD induced by multiple metal co-exposures through the integration of occupational epidemiology and adverse outcome pathway (AOP). The study participants included 401 male mine workers whose blood metal, β2-microglobulin (β2-MG), and cystatin C (Cys-C) levels were measured. Generalized linear models (GLMs), quantile g-computation models (qgcomp), least absolute shrinkage and selection operator (LASSO), and bayesian kernel machine regression (BKMR) were utilized to identify critical nephrotoxic metals. The mean concentrations of lead, cadmium, mercury, arsenic, and manganese were 191.93, 3.92, 4.66, 3.11, 11.35, and 16.33 µg/L, respectively. GLM, LASSO, qgcomp, and BKMR models consistently identified lead, cadmium, mercury, and arsenic as the primary contributors to kidney toxicity. Based on our epidemiological analysis, we used a computational toxicology method to construct a chemical-genetic-phenotype-disease network (CGPDN) from the Comparative Toxicogenomics Database (CTD), DisGeNET, and GeneCard databases, and further linked key events (KEs) related to kidney toxicity from the AOP-Wiki and PubMed databases. Finally, an AOP framework of multiple metals was constructed by integrating the common molecular initiating events (reactive oxygen species) and KEs (MAPK signaling pathway, oxidative stress, mitochondrial dysfunction, DNA damage, inflammation, hypertension, cell death, and kidney toxicity). This is the first AOP network to elucidate the internal association between multiple metal co-exposures and CKD, providing a crucial basis for the risk assessment of multiple metal co-exposures.

Association between urinary cobalt exposure and kidney stones in U.S. adult population: results from the National Health and Nutrition Examination Survey

PURPOSE

Heavy metal exposure can cause impaired or reduced pathology in the kidneys, lungs, liver, and other vital organs. However, the relationship between heavy metal exposure and kidney stones has not been determined. The goal of this research was to determine the association between heavy metal exposure and kidney stones in a population of American adults in general.

MATERIALS AND METHODS

We evaluated 29,201 individuals (≥20 years) from the National Health and Nutrition Examination Survey (NHANES). The association between heavy metal exposure and kidney stones was verified by multiple logistic regression and restricted cubic spline (RCS) regression. Dose-response curves were generated to analyze the relationship between heavy metal concentrations and the occurrence of kidney stones. Moreover, we used propensity score matching (PSM) to exclude the effect of confounding variables.

RESULTS

After a rigorous enrollment screening process, we included 8518 participants. Logistic regression showed that urinary cadmium (U-Cd) and urinary cobalt (U-Co) concentrations were significantly different in the kidney stone group before PSM (p < 0.001). Dose-response curves revealed that the occurrence of kidney stones increased significantly with increasing U-Cd and U-Co concentrations. After adjustment for covariates, only biomarkers of U-Co were linked to the occurrence of kidney stones. When the lowest quartile was used as a reference, the 95% confidence intervals (95% CIs) for kidney stones across the other quartiles were 1.015 (0.767-1.344), 1.409 (1.059-1.875), and 2.013 (1.505-2.693) for U-Cos (p < 0.001).

CONCLUSION

In the U.S. population, high U-Co levels are positively correlated with the potential risk of kidney stones.

Attenuation of inflammation, oxidative stress and TGF-β1/Smad3 signaling and upregulation of Nrf2/HO-1 signaling mediate the protective effect of diallyl disulfide against cadmium nephrotoxicity

Heavy metals are toxic environmental pollutants with serious health effects on humans and animals. Cadmium (Cd) is known for its serious nephrotoxic effect and its toxicity involves oxidative stress (OS) and inflammation. Diallyl disulfide (DADS), a main constituent of garlic, exhibites cytoprotective and antioxidant activities. This study investigated the effect of DADS on OS, inflammation, and fibrosis induced by Cd in rat kidney, pointing to the involvement of transforming growth factor-β (TGF-β)/Smad3 and nuclear factor erythroid 2-related factor 2 (Nrf2)/heme oxygenase-1 (HO-1) signaling, and peroxisome proliferator-activated receptor gamma (PPARγ). Rats received DADS for 14 days and Cd on day 7 and blood and kidney samples were collected. Cd elevated serum creatinine, urea and uric acid, provoked kidney histopathological alterations and collagen deposition, increased kidney malondialdehyde (MDA) level, and decreased glutathione (GSH) and antioxidant enzymes. Nuclear factor-kappaB (NF-κB) p65, interleukin (IL)-6, tumor necrosis factor (TNF)-α, IL-1β, and CD68 were upregulated in Cd-administered rat kidney. DADS prevented kidney injury, mitigated OS, suppressed NF-κB, CD68 and pro-inflammatory mediators, and boosted antioxidants. DADS downregulated TGF-β1, Smad3 phosphorylation and Kelch-like ECH-associated protein-1 (Keap1), and increased Nrf2, HO-1, cytoglobin, and PPARγ. In conclusion, DADS protects the kidney against Cd toxicity by attenuating OS, inflammation, and TGF-β1/Smad3 signaling, and enhancement of Nrf2/HO-1 signaling, antioxidants, and PPARγ.

Iron Administration Partially Ameliorates Cadmium-Induced Oxidative Damage in the Liver and Kidney of Rats

The protective effect of Fe against Cd-induced toxicity in the liver and kidney of rats during concurrent administration of both metals was investigated in this study. Fifty female rats (130-150 g) were distributed into five groups of 10 rats each (n = 10): Group I (control), received normal saline solution; Group II (1.2 mg CdCl2/kg b.w.); Group III (1.2 mg CdCl2 + 0.25 mg FeCl2/kg b.w.); Group IV (1.2 mg CdCl2 + 0.75 mg FeCl2/kg b.w.); and Group V (1.2 mg CdCl2 + 1.5 mg FeCl2/kg b.w.). Administration of both tested substances lasted for 47 days. Cd was injected intraperitoneally once a week, while Fe was administered to the Cd-exposed animals by oral gavage thrice weekly. The animals were killed at the end of the study, their blood was collected, and their liver and kidneys were harvested for biochemical and histological analysis. Following Cd administration, the kidney and liver showed a significant increase in Cd concentration, while Fe concentration in the kidney decreased. However, cotreatment with Fe decreased Cd concentration in the kidney and liver and increased Fe concentration in the kidney but not the liver, and the effect was more pronounced in the higher than lower doses. In the kidney, cotreatment with Fe especially at higher doses inhibited Cd-induced lipid peroxidation and plasma uric acid concentration. In the liver, lipid peroxidation which Cd did not alter was found to be elevated after cotreatment with the highest dose Fe. Inflammatory cell infiltrations of the central vein and renal tubular and glomeruli injury induced by Cd were not obviated by Fe cotreatment. It seems that both tissues respond differently to the concurrent administration of these metals and that Fe protected the kidney against oxidative injury-induced by Cd but not histopathological changes in both tissues.

Geoenvironmental determinants influencing chronic kidney disease of unknown etiology in the dry zone of Sri Lanka: a study based on a cohort of at-risk communities

Chronic kidney disease of unknown origin (CKDu) has emerged as a serious health risk for farming communities in remote semi-arid lowland regions of Sri Lanka, with geoenvironmental factors widely believed to be associated with the etiology. Although numerous case-control studies have been carried out to determine the causes of CKDu, none have been conducted in at-risk communities. The main objective of this study is to identify the potential geo-environmental risk factors associated with the at-risk community in the Wilgamuwa region, a CKDu endemic area in Sri Lanka. The study collected and analyzed 92 water sources currently or previously used in the study area for major cations, anions, and trace elements, mainly As, Cd, Pd, Mn, Zn, Ba and Sr. The major cations and anions in CKDu-susceptible groundwater varied Si4+ > Ca2+ > Na+ > Mg2+ > K+ and HCO3- > Cl- > SO42- > NO3- > F- > PO43- > Br-. The higher average values of Si4+, F- and total hardness (TH) were reported in groundwater consumed by communities at risk of CKDu, with average values (in mg/L) of Si4+-46, F--0.62, and TH-178. Considering the Water Quality Index (WQI) values, 73% of groundwater sources are classified as poor water quality, and the groundwater quality mainly depends on the fluoride distribution in the region. According to the Hazard Quotient (HQ), the risk of adverse health effects from exposure to F- and SiO2 increased in magnitude in the order of male < female < children. Health hazards due to As, Cd and Pb exposure fell between the 'no-risk' and 'low-risk' categories. As outlined in this study, continuous monitoring of vulnerable communities for environmental exposures to key groundwater constituents is important in the dry zone of Sri Lanka.

Advancing diabetic wound care: The role of copper-containing hydrogels

Diabetic wounds pose a significant challenge in healthcare due to their complex nature and the difficulties they present in treatment and healing. Impaired healing processes in individuals with diabetes can lead to complications and prolonged recovery times. However, recent advancements in wound healing provide reasons for optimism. Researchers are actively developing innovative strategies and therapies specifically tailored to address the unique challenges of diabetic wounds. One focus area is biomimetic hydrogel scaffolds that mimic the natural extracellular matrix, promoting angiogenesis, collagen deposition, and the healing process while also reducing infection risk. Copper nanoparticles and copper compounds incorporated into hydrogels release copper ions with antimicrobial, anti-inflammatory, and angiogenic properties. Copper reduces infection risk, modulates inflammatory response, and promotes tissue regeneration through cell adhesion, proliferation, and differentiation. Utilizing copper nanoparticles has transformative potential for expediting diabetic wound healing and improving patient outcomes while enhancing overall well-being by preventing severe complications associated with untreated wounds. It is crucial to write a review highlighting the importance of investigating the use of copper nanoparticles and compounds in diabetic wound healing and tissue engineering. These groundbreaking strategies hold the potential to transform the treatment of diabetic wounds, accelerating the healing process and enhancing patient outcomes.

Algorayed R, Bakry N. The Protective Activity of Withania somnifera Against Mercuric Chloride (HgCl2)-Induced Renal Toxicity in Male Rats

The purpose of this study was to test the protective effect of Withania somnifera (WS) against the harmful effects of mercuric chloride (HgCl2)-induced kidney failure at the histological, biochemical, and immune levels in Wistar rats. The study assessed the biochemical and immunological changes in five groups (n = 6): Group 1 (G1) was the negative control, and the other rats received a single subcutaneous dose of HgCl2 (2.5 mg/kg in 0.5 mL of 0.9% saline solution) and randomly divided into 4 groups. Group 2 (G2) was the positive control and left without treatment. Groups 3, 4, and 5 (G3, G4, and G5) were treated with different doses of WS root powder for 30 days. The HgCl2-positive group showed significant signs of renal toxicity as reflected by increased levels of kidney function parameters (blood urea nitrogen, urea, and creatinine), inflammatory biomarkers, immunological indices (SDF-1, IL-6, NGAL, and KIM-1), and oxidative stress (SOD, TAC, CAT, GSH, and MDA). The positive group rats also showed drastic pathological changes in renal tissues. Different doses of WS treatment significantly reduced the levels of all biochemical markers and decreased pathological damage to the kidney tissues. The antioxidant, phenolic, and flavonoid constituents of WS root powder helped protect rats' kidneys against HgCl2-induced kidney toxicity in male rats.

The role of age and sex in non-linear dilution adjustment of spot urine arsenic

BACKGROUND

Previous research introduced V-PFCRC as an effective spot urinary dilution adjustment method for various metal analytes, including the major environmental toxin arsenic. V-PFCRC normalizes analytes to 1 g/L creatinine (CRN) by adopting more advanced power-functional corrective equations accounting for variation in exposure level. This study expands on previous work by examining the impacts of age and sex on corrective functions.

METHODS

Literature review of the effects of sex and age on urinary dilution and the excretion of CRN and arsenic. Data analysis included a Data Set 1 of 5,752 urine samples and a partly overlapping Data Set 2 of 1,154 combined EDTA blood and urine samples. Both sets were classified into age bands, and the means, medians, and interquartile ranges for CRN and TWuAs in uncorrected (UC), conventionally CRN-corrected (CCRC), simple power-functional (S-PFCRC), sex-aggregated (V-PFCRC SA), and sex-differentiated V-PFCRC SD modes were compared. Correlation analyses assessed residual relationships between CRN, TWuAs, and age. V-PFCRC functions were compared across three numerically similar age groups and both sexes. The efficacy of systemic dilution adjustment error compensation was evaluated through power-functional regression analysis of residual CRN and the association between arsenic in blood and all tested urinary result modes.

RESULTS

Significant sex differences in UC and blood were neutralized by CCRC and reduced by V-PFCRC. Age showed a positive association with blood arsenic and TWuAs in all result modes, indicating factual increments in exposure. Sex-differentiated V-PFCRC best matched the sex-age kinetics of blood arsenic. V-PFCRC formulas varied by sex and age and appeared to reflect urinary osmolality sex-age-kinetics reported in previous research. V-PFCRC minimized residual biases of CRN on TWuAs across all age groups and sexes, demonstrating improved standardization efficacy compared to UC and CCRC arsenic.

INTERPRETATION

Sex differences in UC and CCRC arsenic are primarily attributable to urinary dilution and are effectively compensated by V-PFCRC. While the sex and age influence on V-PFCRC formulas align with sex- and age-specific urinary osmolality and assumed baseline vasopressor activities, their impact on correction validity for entire collectives is minimal.

CONCLUSION

The V-PFCRC method offers a robust correction for urinary arsenic dilution, significantly reducing systemic dilution adjustment errors. Its application in various demographic contexts enhances the accuracy of urinary biomarker assessments, benefiting clinical and epidemiological research. V-PFCRC effectively compensates for sex differences in urinary arsenic. Age-related increases in TWuAs are exposure-related and should be additionally accounted for by algebraic normalization, covariate models, or standard range adjustments.

Low-level, chronic ingestion of lead and cadmium: The unspoken danger for at-risk populations

The long-term effects of low-level, chronic exposure to lead and cadmium through ingestion are often overlooked, despite the urgency surrounding the clinical onset and worsening of certain pathologies caused by these metals. This work reviews current legislation, global ingestion levels, and blood levels in the general population to emphasize the need for reactivity towards this exposure, especially in at-risk populations, including patients with early-stage renal and chronic kidney disease. Global data indicates persistent chronic ingestion of lead and cadmium, with no decreasing trend in recent years, and a daily consumption of tens of micrograms worldwide. Moreover, the average blood lead and cadmium levels in the general population are concerning in many countries with some significantly exceeding healthy limits, particularly for children. Technologies developed to cleanse soil and prevent heavy metal contamination in food are not yet applicable on a global scale and remain financially inaccessible for many communities. Addressing this chronic ingestion at the human level may prove more beneficial in delaying the onset of associated clinical pathologies or preventing them all together.

Farnesol attenuates cadmium-induced kidney injury by mitigating oxidative stress, inflammation and necroptosis and upregulating cytoglobin and PPARγ in rats

Heavy metals are environmental pollutants that can harm animals and humans even at low concentrations. Cadmium (Cd) is known for its serious health effects on different organs and its toxicity is associated with oxidative stress (OS) and inflammation. Farnesol (FAR), a sesquiterpene alcohol found in many vegetables and fruits, possesses promising anti-inflammatory and antioxidant activities. This study evaluated the effect of FAR on Cd-induced kidney injury, pinpointing its effect of the redox status, inflammation, fibrosis and necroptosis. Rats in this study received FAR for 14 days and Cd on day 7. Elevated serum creatinine, urea and uric acid, and several kidney histopathological alterations were observed in Cd-administered rats. Cd increased MDA, decreased antioxidants, downregulated PPARγ and upregulated NF-κB p65, IL-6, TNF-α, and IL-1β. Necroptosis mediators (RIP1, RIP3, MLKL, and caspase-8) and α-SMA were upregulated, and collagen deposition was increased in Cd-administered rats. FAR ameliorated kidney injury markers and tissue damage, attenuated OS, suppressed NF-κB and inflammatory mediators, and enhanced antioxidants. In addition, FAR suppressed RIP1, RIP3, MLKL, caspase-8, and α-SMA, and enhanced kidney cytoglobin and PPARγ. In conclusion, FAR protects against Cd nephrotoxicity by suppressing OS, inflammatory response and necroptosis, effects associated with enhanced antioxidants, cytoglobin, and PPARγ.

Co-exposure to multiple heavy metals and metalloid induces dose dependent modulation in antioxidative, inflammatory, DNA damage and apoptic pathways progressing to renal dysfunction in mice

Humans are exposed to a cocktail of heavy metal toxicants at the same time in the environment rather than single metal. The kidney is often a site of early damage due to high renal contact to these pollutants. This study was done to examine the cumulative toxic effect of multiple elements prevalent in the environment. To explore the effect of subchronic exposure to heavy metal mixture male and female Swiss albino mice were randomly divided into 14 groups and given varying doses [MPL (maximum permissible limit), 1X, 5X, 10X, 50X, or 100X] of the multiple metals and metalloid mixtures via drinking water for 8 weeks. It was determined that metal treatment caused increased metal load in renal tissue. The kidney function deteriorated in response to 10X, 50X, 100X concentration of the dosing mixture was found associated to oxidative stress, glomerular damage, necrosis, cell death and further exacerbation of the inflammation.

Trigger Warning: How Modern Diet, Lifestyle, and Environment Pull the Trigger on Autosomal Dominant Polycystic Kidney Disease Progression

Understanding chronic kidney disease (CKD) through the lens of evolutionary biology highlights the mismatch between our Paleolithic-optimized genes and modern diets, which led to the dramatically increased prevalence of CKD in modern societies. In particular, the Standard American Diet (SAD), high in carbohydrates and ultra-processed foods, causes conditions like type 2 diabetes (T2D), chronic inflammation, and hypertension, leading to CKD. Autosomal dominant polycystic kidney disease (ADPKD), a genetic form of CKD, is characterized by progressive renal cystogenesis that leads to renal failure. This review challenges the fatalistic view of ADPKD as solely a genetic disease. We argue that, just like non-genetic CKD, modern dietary practices, lifestyle, and environmental exposures initiate and accelerate ADPKD progression. Evidence shows that carbohydrate overconsumption, hyperglycemia, and insulin resistance significantly impact renal health. Additionally, factors like dehydration, electrolyte imbalances, nephrotoxin exposure, gastrointestinal dysbiosis, and renal microcrystal formation exacerbate ADPKD. Conversely, carbohydrate restriction, ketogenic metabolic therapy (KMT), and antagonizing the lithogenic risk show promise in slowing ADPKD progression. Addressing disease triggers through dietary modifications and lifestyle changes offers a conservative, non-pharmacological strategy for disease modification in ADPKD. This comprehensive review underscores the urgency of integrating diet and lifestyle factors into the clinical management of ADPKD to mitigate disease progression, improve patient outcomes, and offer therapeutic choices that can be implemented worldwide at low or no cost to healthcare payers and patients.

Relationship between exposure to heavy metals on the increased health risk and carcinogenicity of urinary tract (kidney and bladder)

In today's society, with the continuous development of manufacturing industries and factories related to chemicals, the amount of heavy metals in the inhaled air of humans, water and even food consumption has increased dramatically. The aim of this study was investigation of relationship between exposure to heavy metals on the increased carcinogenicity risk of kidney and bladder. Databases used to for searched were the Springer, Google Scholar, Web of Science, Science Direct (Scopus) and PubMed. At the end after sieve we selected 20 papers. Identify all relevant studies published 2000-2021. The results of this study showed that exposure to heavy metals due to the bio accumulative properties of these metals can cause kidney and bladder abnormalities and provide the basis through various mechanisms for malignant tumors in these organs. Based on result this study, since a limited number of heavy metals including copper, iron, zinc and nickel in very small amounts as micronutrients play a very important role in the function of enzymes and the body cells biological reactions, but exposure to some of them like arsenic, lead, vanadium and mercury will cause irreversible effects on people's health and cause various diseases including cancers of the liver, pancreas, prostate, breast, kidney and bladder. The kidneys, ureter and bladder are the most important organs in the urinary tract on human. According to the result of this study, the duty of this urinary system is to remove toxins, chemicals and heavy metals from the blood, balance electrolytes, excrete excess fluid, produce urine and transfer it to the bladder. This mechanism causes the kidneys and bladder to be highly associated with these toxins and heavy metals, which can lead to various diseases in these two important organs. According to the finding the reducing exposure to heavy metals in various ways can prevent many diseases related to this system and reduce the incidence of kidney and bladder cancers.

Prevalence of Chronic Kidney Disease and its Association with Pesticide Exposure in Bargarh District, Odisha, India

Background

Bargarh, a district in Odisha, is known for intense agricultural activities because of uninterrupted irrigation from the Hirakud reservoir. The number of chronic kidney disease (CKD) cases in the district is increasing rapidly. The present study assesses the prevalence of CKD and CKDu (of unknown etiology) in the district and its association with pesticide application.

Materials and Methods

A door-to-door survey was conducted to find out the CKD hotspots in the different blocks of the district with the help of primary and community health centers. The prevalence of CKD in the identified hotspot villages was assessed using a random clustered sampling method along with the collection of data related to age, sex, occupation and source of drinking water. Soil and water samples collected from identified hotspot and nonhotspot villages were analyzed to assess the presence of nephrotoxic pesticide residues.

Results

A total of 16 villages were identified with high CKD prevalence rates and designated as hotspot villages. Data indicate that about 21% of males under ≥ 40 years age group were found to be suffering from CKD. Cases of CKDu (85%) were more prominent in these hotspot villages. Analysis of soil and water samples demonstrated the presence of seven different nephrotoxic pesticides above the maximum residues levels (MRLs) in hotspot villages compared to nonhotspot villages.

Conclusion

The presence of nephrotoxic pesticides above MRLs in the hotspot villages indicates their possible association with the onset and progression of CKD among the exposed population. Further research is needed to establish their causative association with CKDu in the study region.

Quercetin alleviates kidney damage caused by mercury Chloride: The protective effects of quercetin on autophagy and inflammation were studied based on TRIM32/TLR4/LC3 pathway

OBJECTIVE

Mercury is one of the heavy metal pollutants causing serious harm to human health. Quercetin was observed to repair kidney damage through the TLR4/TRIM32 pathway, and the detoxification effect of quercetin on heavy metal poisoning was observed.

METHODS

For the study, the researchers divided 40 male mice from the KM strain into five groups: control, HgCl2, QU30, HgCl2+QU15, and HgCl2+QU30. The biological effects of those mice in each group were detected by the biochemical experiment, histopathology experiment and protein expression experiment respectively.

RESULTS

HgCl2 had effects in increasing the level of malondialdehyde (MDA) and decreasing the activity of antioxidant enzymes (P < 0.05). HgCl2 induced inflammation by increasing tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), interleukin-1β (IL-1β) and Toll Like Receptor 4 (TLR-4) (P < 0.05). The expression of creatinine (CRE) and urea nitrogen (BUN) showed that HgCl2 promoted kidney injury. HgCl2 altered renal tissue integrity and TRIM32 expression which resulted in the increased autophagy associated protein levels of LC3. In contrast, quercetin reduced oxidative stress, autophagy, inflammation and histopathological changes (P < 0.05).

CONCLUSION

Quercetin has the renal protection effects of anti-inflammation, anti-oxidation and anti-autophagy.

Nerve Epidermal Growth Factor-Like 1 Protein (NELL-1) Expression in Mercury-Related Membranous Nephropathy: Is It a True Association or a Chance Occurrence?

Background

Neural epidermal-like growth factor-like 1 (NELL-1) is a protein kinase C binding protein expressed in osteoblasts and renal tubules. It is expressed in 5%-25% glomerular cells at the mRNA level. Membranous Nephropathy (MN) is characterized by the presence of antibodies against certain types of antigens on the glomerular basement membrane. The most common one implicated in primary MN is an antibody against PLA2R. Many newer antigens have been discovered in the recent past, which are proven to cause secondary MN, one of which is NELL-1. NELL-1 has been associated with malignancy-associated MN and also recently associated with traditional indigenous medications containing mercury. In this study, we study the expression of NELL-1 in mercury-associated MN.

Materials and Methods

Records of ten cases of Mercury -associated MN were retrieved from the Institute medical archives and NELL-1 Immunohistochemistry was performed in all ten cases.

Results

NELL-1 was found to be positive in 50% of the cases of Mercury associated MN. In addition, mass spectrometric studies was performed, which revealed the common Mercuric compound associated to be 'Swaskalpa', 'Sudarshana Melugu' and 'Rasagandhi Mezhugu'.

Conclusion

This study highlights why it is important to diagnose mercury-associated MN by a pathologist by picking up the finer histopathological clues and by using NELL-1 immunohistochemistry, especially in PLA2R-negative patients. The former is true as most of the time a history of mercuric compound intake is missed out.

Transcriptome Analysis of the Effect of Nickel on Lipid Metabolism in Mouse Kidney

Although the human body needs nickel as a trace element, too much nickel exposure can be hazardous. The effects of nickel on cells include inducing oxidative stress, interfering with DNA damage repair, and altering epigenetic modifications. Glucose metabolism and lipid metabolism are closely related to oxidative stress; however, their role in nickel-induced damage needs further study. In Institute of Cancer Research (ICR) mice, our findings indicated that nickel stress increased the levels of blood lipid indicators (triglycerides, high-density lipoprotein, and cholesterol) by about 50%, blood glucose by more than two-fold, and glycated serum protein by nearly 20%. At the same time, nickel stress increased oxidative stress (malondialdehyde) and inflammation (Interleukin 6) by about 30% in the kidney. Based on next-generation sequencing technology, we detected and analyzed differentially expressed genes in the kidney caused by nickel stress. Bioinformatics analysis and experimental verification showed that nickel inhibited the expression of genes related to lipid metabolism and the AMPK and PPAR signaling pathways. The finding that nickel induces kidney injury and inhibits key genes involved in lipid metabolism and the AMPK and PPAR signaling pathways provides a theoretical basis for a deeper understanding of the mechanism of nickel-induced kidney injury.

Association between Liver and Kidney Function and Birth Outcomes in Pregnant Surinamese Women Exposed to Mercury and Lead in the Caribbean Consortium for Research in Environmental and Occupational Health (CCREOH) Environmental Epidemiologic Cohort Study

Exposure to mercury (Hg) and lead (Pb), in combination with liver and kidney impairment, may result in adverse birth outcomes. From 408 women in the age range of 16 to 46 years, living in rural and urban areas in the interior of Suriname, we looked at the association between adverse birth outcomes and exposure to Hg and Pb in combination with liver and kidney function. This group of women represented a subcohort of pregnant women who participated in the Caribbean Consortium for Research in Environmental and Occupational Health (CCREOH)-Meki Tamara study. Liver function was assessed by measuring aspartate amino transferase (AST), alanine amino transferase (ALT), and gamma-glutamyl transferase (GGT). Kidney function was assessed by measuring creatinine, urea, and cystatin C. We defined preterm births as birth before 37 weeks of gestation, low birthweight as birthweight < 2500 g, and low Apgar score as a score < 7 at 5 min, and these were used as indicators for adverse birth outcomes. Small size for gestational age was defined as gestational age < -2SD weight for GA. We found significant statistical associations between biomarkers for liver and kidney functions and adverse birth outcomes Apgar score and gestational age. No significant association was found between heavy metals Hg and lead and adverse birth outcomes.

Analysis of relationship between mixed heavy metal exposure and early renal damage based on a weighted quantile sum regression and Bayesian kernel machine regression model

BACKGROUND

Occupation, environmental heavy metal exposure, and renal function impairment are closely related. The relationship between mixed metal exposure and chronic renal injury is inadequately described, and the interaction between each metal is poorly explored.

OBJECTIVE

This cross-sectional study assessed mixed heavy metal exposure in the general population and their relationship with early renal impairment, as well as possible interactions between metals.

METHODS

The study was conducted in two communities in Taiyuan City in northern China. Multiple linear regression, weighted quantile sum (WQS) and bayesian kernel machine regression (BKMR) regression were used to explore the relationship of mixed heavy metal exposure with indicators of early kidney injury (N-acetyl-β-D- glucosidase (UNAG), urinary albumin (UALB)). Meanwhile, BKMR was used to explore the possible interactions between mixed heavy metal and indicators of early kidney injury.

RESULTS

Based on the WQS regression results, we observed adjusted WQS coefficient β (β-WQS) of 0.711 (95% CI: 0.543, 0.879). Notably, this change was primarily driven by As (35.6%) and Cd (22.5%). In the UALB model, the adjusted β-WQS was 0.657 (95% CI: 0.567, 0.747), with Ni (30.5%), Mn (22.1%), Cd (21.2%), and As (18.6%) exhibiting higher weights in the overall effect. The BKMR results showed a negative interaction between As and other metals in the UNAG and UALB models, a positive interaction between Mn and Ni and other metals. No significant pairwise interaction was observed in the association of metals with indicators of early kidney injury.

CONCLUSION

Through multiple linear regression, WQS regression, and BKMR analyses, we found that exposure to mixed heavy metals such as Cd, Cr, Pb, Mn, As, Co and Ni was positively correlated with UNAG and UALB. Moreover, there are complex interactions between two or more heavy metals in more than one direction.

Perindopril Dampens Cd-induced Nephrotoxicity by Suppressing Inflammatory Burden, Ang II/Ang 1-7, and Apoptosis Signaling Pathways

Cadmium (Cd) is one of the most abundant toxic heavy metals, and its exposure is linked to serious kidney intoxication, a major health problem. Evidence reported that inflammatory damage is a key factor in Cd renal intoxication. Perindopril (PER) is an angiotensin-converting enzyme inhibitor approved for treating hypertension and other cardiovascular problems. Significantly, RAS activation results in inflammatory damage. Our study aimed to examine the renoprotective effects of PER in Cd-induced nephrotoxicity, the impact of inflammation, and the underlying molecular mechanisms. PER was given at a dose of 1 mg/kg per day. Cd was injected at a dose of 1.2 mg/kg, as a single dose. Treatment with PER led to a significant decrease in serum levels of urea, creatinine, uric acid, and urine albumin/creatinine ratio. PER effectively mitigated inflammation by decreasing MPO, NO, IL-1β, IL-6, and INF-γ levels mediated by downregulating NF-κB expression and suppressing JAK-1 and STAT3 phosphorylation. PER modulates Ang II/Ang 1-7 axis in Cd-intoxicated rats by decreasing Ang II expression and increasing Ang-(1-7) expression. PER inhibits Cd-induced apoptosis by lowering Bax, cytochrome c, and cleaved caspase 3 expressions while increasing Bcl-2 expression. In conclusion, PER dampens Cd-induced kidney intoxication by modulating Ang II/Ang 1-7 axis, suppressing NF-κB, JAK-1/STAT3, and apoptosis signals.

Commercially available mouthguards: Unearthing trace elements for the first time

The use of mouthguards is advocated by the American Dental Association for orofacial injury prevention and teeth protection. However, the chemical environment in the mouth may cause harmful substances within the mouthguard's polymer material to leach out and be absorbed by the user. Considering this, the present study for the first time analyzed commercially available mouthguards and disclosed the presence of trace elements. Specifically, an analytical method was developed based on closed-vessel microwave-assisted digestion and plasma-based atomic spectrometry for determining toxic trace elements in mouthguard samples. Initially, 75 elements were assessed and, thereafter, quantified cadmium (Cd), copper (Cu) and lead (Pb) in each sample by inductively coupled plasma mass spectrometry (ICP-MS). Method validation was carried out by analyzing a certified reference material of Low-Density Polyethylene, and by addition and recovery experiments. Results for copper were further validated by ICP optical emission spectrometry (ICP-OES). While most samples exhibited elemental levels beneath the method's limit of quantification, Cd, Cu and Pb were detected in four samples. Remarkably, one sample had Cu levels exceeding safe limits by 109 times, highlighting potential toxicity risks. This initial research underscores the need for stricter contamination control in mouthguard materials to minimize potentially health hazards.

Metals on the Menu-Analyzing the Presence, Importance, and Consequences

Metals are integral components of the natural environment, and their presence in the food supply is inevitable and complex. While essential metals such as sodium, potassium, magnesium, calcium, iron, zinc, and copper are crucial for various physiological functions and must be consumed through the diet, others, like lead, mercury, and cadmium, are toxic even at low concentrations and pose serious health risks. This study comprehensively analyzes the presence, importance, and consequences of metals in the food chain. We explore the pathways through which metals enter the food supply, their distribution across different food types, and the associated health implications. By examining current regulatory standards for maximum allowable levels of various metals, we highlight the importance of ensuring food safety and protecting public health. Furthermore, this research underscores the need for continuous monitoring and management of metal content in food, especially as global agricultural and food production practices evolve. Our findings aim to inform dietary recommendations, food fortification strategies, and regulatory policies, ultimately contributing to safer and more nutritionally balanced diets.

Leukocyte Telomere Length Mediates the Associations between Blood Lead and Cadmium with Hypertension among Adults in the United States: A Cross-Sectional Study

There is evidence to support the links between lead and cadmium exposure with hypertension and also with leukocyte telomere length (LTL). The objective of this study is to investigate the role that LTL may play in the relationship between lead and cadmium exposure and hypertension. This study consisted of 3718 participants from the National Health and Nutrition Examination Survey (NHANES) 1999-2002. Logistic regression was used to analyze the relationship between blood metals with hypertension, and the mediating model was used to evaluate the mediating effect of LTL. In the fully adjusted model, both blood lead and cadmium ln-transformed concentrations were significantly positively associated with hypertension risk, as were all quartiles of blood lead. Additionally, we observed positive linear dose-response relationships with hypertension by restricted cubic spline analysis (both p overall < 0.001, p non-linear = 0.3008 for lead and p non-linear = 0.7611 for cadmium). The ln-transformed blood lead and cadmium concentrations were associated with shorter LTL. LTL was inversely related to hypertension and the OR was 0.65 (95% CI: 0.47 to 0.89). Furthermore, LTL had mediating effects on the associations of blood lead and cadmium with hypertension risk, and the mediation proportions were 2.25% and 4.20%, respectively. Our findings suggested that exposure to lead and cadmium raised the risk of hypertension, while LTL played as a mediating factor.

Concentration and Distribution of Toxic and Essential Elements in Traditional Rice Varieties of Sri Lanka Grown on an Anuradhapura District Farm

Toxic heavy metals have been the focus of many investigations into chronic kidney disease of unknown aetiology (CKDu) within Sri Lanka. It has been hypothesised that exposure to nephrotoxic arsenic, cadmium and lead could play a role in the development of CKDu, and these metals have previously been found in unsafe concentrations in Sri Lankan rice. Traditional varieties of Sri Lankan rice remain popular due to their perceived health benefits, but their uptake of trace and toxic heavy metals remained unexplored. Here, we report a one-time, cross-sectional dataset on the concentrations of essential and toxic elements present in eleven samples of polished and unpolished traditional rice varieties, all regularly grown and sold in the Anuradhapura district, a CKDu hotspot. All rice was sourced from the same farm, with the exception of one store bought sample grown on another, unidentified farm. Cadmium concentrations varied significantly between varieties, and potentially unsafe concentrations of cadmium were detected in the store-bought sample (Suwadel, 113±13 μg kg-1). Elemental imaging of the grains revealed lead to be stored mainly in the rice bran, which is removed during polishing, while cadmium was distributed in the edible portion of the grain. Essential elements were generally higher in the traditional rice varieties than those reported for non-traditional varieties and are a potential source of trace elements for nutrient-deficient communities. The concentration of selenium, an element that plays a protective role in the kidneys, was too low to provide the minimum recommended intake. The methods developed in this study could be applied to a more comprehensive study of elemental uptake of rice under controlled growing conditions.

Translational toxicology of metal(loid) species: linking their bioinorganic chemistry in the bloodstream to organ damage onset

The quantification of arsenic, mercury, cadmium and lead in the human bloodstream is routinely used today to assess exposure to these toxic metal(loid)s, but the interpretation of the obtained data in terms of their cumulative health relevance remains problematic. Seemingly unrelated to this, epidemiological studies strongly suggest that the simultaneous chronic exposure to these environmental pollutants is associated with the etiology of autism, type 2 diabetes, irritable bowel disease and other diseases. This from a public health point of view undesirable situation urgently requires research initiatives to establish functional connections between human exposure to multiple toxic metal(loid) species and adverse health effects. One way to establish causal exposure-response relationships is a molecular toxicology approach, which requires one to unravel the biomolecular mechanisms that unfold after individual toxic metal(loid)s enter the bloodstream/organ nexus as these interactions ultimately determine which metabolites impinge on target organs and thus provide mechanistic links to diseases of unknown etiology. In an attempt to underscore the importance of the toxicological chemistry of metal(loid)s in the bloodstream, this review summarizes recent progress into relevant bioinorganic processes that are implicated in the etiology of adverse organ-based health effects and possibly diseases. A better understanding of these bioinorganic processes will not only help to improve the regulatory framework to better protect humans from the adverse effects of toxic metal(loid) species, but also represents an important starting point for the development of treatments to ameliorate pollution-induced adverse health effects on human populations, including pregnant women, the fetus and children.

Complementary and Alternative Medicine Use and Glomerular Disease: A Contemporary Case Series

Rationale & Objective

Complementary and alternative medicine (CAM) intake is widely prevalent in many parts of India. Heavy metals are known ingredients in some of these formulations. We studied the spectrum of glomerular diseases in patients using CAM.

Study Design

Case series.

Setting & Participants

Patients with proteinuria or unexplained acute kidney injury, who underwent a kidney biopsy between May 2021 and September 2022, and who provided a history of recent CAM intake were included in the study. For patients enrolled prospectively, blood and urine samples were analyzed using mass spectrometry for the presence of mercury, lead, arsenic and cadmium. The CAM formulation, when available, was analyzed using inductively coupled plasma-optical emission spectroscopy.

Results

Twenty-eight patients were enrolled in the study, with a median duration of CAM intake of 4 months (interquartile range, 2-6 months). Heavy metal screening was performed in 17 patients, of whom 15 had elevated urine mercury levels, 10 had elevated blood mercury levels, and 1 had elevated blood and urine arsenic levels. Of the 6 CAM formulations that were analyzed, all had high levels of mercury. Kidney biopsy findings were membranous nephropathy (n = 19), minimal change disease (n = 8), and mesangial proliferative glomerulonephritis (n = 1). Of the 19 patients with membranous nephropathy, 14 were associated with neural epidermal growth factor-like protein 1 (NELL-1). With conservative management alone, 17 patients achieved complete remission.

Limitations

Not all patients underwent blood and urine mercury testing, and only 6 patients provided the CAM samples for analysis. Furthermore, occupational and residential exposure to mercury could not be excluded.

Conclusions

The most common kidney pathology noted in our study was membranous nephropathy, which was predominantly associated with neural epidermal growth factor-like protein 1. A significant proportion of the patients recovered completely after withdrawal of the offending agent and initiation of renin-angiotensin system blockade.

Heavy metal poisoning caused by Chinese folk remedies in psoriasis patients: a retrospective analysis

Psoriasis, characterized as a chronic relapsing disease with a protracted course, often drives patients to seek relief through Chinese folk remedies (CFR). Nonetheless, the complex compositions of these remedies frequently result in unintended adverse effects, notably various types of heavy metal poisoning. Our study involved an exhaustive collection and analysis of clinical data from psoriasis patients who developed heavy metal poisoning due to CFR usage, admitted to Beijing Chao-Yang Hospital from January 2011 to October 2023. Our analysis identified 44 cases of mercury poisoning, 17 of lead poisoning, 21 of arsenic poisoning, and 4 instances of mixed heavy metal poisoning. The folk remedies used ranged from fumigation and inhalation to skin application and oral administration. Distinct pathogenic characteristics were observed in each poisoning type. After treatment with metal chelating agents, all patients experienced a reduction in heavy metal levels in their bodies, accompanied by varying degrees of symptom alleviation. This study underscores the vital necessity of opting for formal, medically approved treatments for psoriasis, thereby avoiding the hazardous consequences of unregulated folk remedies that may lead to severe heavy metal poisoning.

Functional metabolomics reveals arsenic-induced inhibition of linoleic acid metabolism in mice kidney in drinking water

Arsenic (As) is a heavy metal known for its detrimental effects on the kidneys, but the precise mechanisms underlying its toxicity remain unclear. In this study, we employed an integrated approach combining traditional toxicology methods with functional metabolomics to explore the nephrotoxicity induced by As in mice. Our findings demonstrated that after 28 days of exposure to sodium arsenite, blood urea nitrogen, serum creatinine levels were significantly increased, and pathological examination of the kidneys revealed dilation of renal tubules and glomerular injury. Additionally, uric acid, total cholesterol, and low-density lipoprotein cholesterol levels were significant increased while triglyceride level was decreased, resulting in renal insufficiency and lipid disorders. Subsequently, the kidney metabolomics analysis revealed that As exposure disrupted 24 differential metabolites, including 14 up-regulated and 10 down-regulated differential metabolites. Ten metabolic pathways including linoleic acid and glycerophospholipid metabolism were significantly enriched. Then, 80 metabolic targets and 168 predicted targets were identified using metabolite network pharmacology analysis. Of particular importance, potential toxicity targets, such as glycine amidinotransferase, mitochondrial (GATM), and nitric oxide synthase, and endothelial (NOS3), were prioritized through the "metabolite-target-pathway" network. Receiver operating characteristics curve and molecular docking analyses suggested that 1-palmitoyl-2-myristoyl-sn-glycero-3-PC, linoleic acid, and L-hydroxyarginine might be functional metabolites associated with GATM and NOS3. Moreover, targeted verification result showed that the level of linoleic acid in As group was 0.4951 μg/mL, which was significantly decreased compared with the control group. And in vivo and in vitro protein expression experiments confirmed that As exposure inhibited the expression of GATM and NOS3. In conclusion, these results suggest that As-induced renal injury may be associated with the inhibition of linoleic acid metabolism through the down-regulation of GATM and NOS3, resulting in decreased levels of linoleic acid, 1-palmitoyl-2-myristoyl-sn-glycero-3-PC, and L-hydroxyarginine metabolites.

Epigallocatechin-3-gallate attenuates arsenic-induced fibrogenic changes in human kidney epithelial cells through reversal of epigenetic aberrations and antioxidant activities

Renal fibrosis is a pathogenic intermediate stage of chronic kidney disease (CKD). Nephrotoxicants including arsenic can cause kidney fibrosis through induction of oxidative stress and epigenetic aberrations. Epigallocatechin-3-gallate (EGCG), a green tea polyphenol, is known to have antioxidant and epigenetic modulation properties. Whether EGCG, through its antioxidant and epigenetic modulating activities, can attenuate fibrogenesis is not known. Therefore, the objective of this study was to determine whether EGCG can attenuate arsenic-induced acute injury and long-term exposure associated fibrogenicity in kidney epithelial cells. To address this question, two human kidney epithelial cell lines Caki-1 and HK-2 exposed to arsenic for both acute and long-term durations were treated with EGCG. The protective effect of EGCG on arsenic-induced cytotoxicity and fibrogenicity were evaluated by measuring the cell growth, reactive oxygen species (ROS) production, genes expression, and epigenetic changes in histone marks. Results revealed that EGCG has a protective effect in arsenic-induced acute cytotoxicity in these cells. EGCG scavenges the increased levels of ROS in arsenic exposed cells. Aberrant expression of fibrogenic genes in arsenic exposed cells were restored by EGCG. Abrogation of arsenic-induced fibrogenic changes was also associated with EGCG-mediated restoration of arsenic-induced aberrant expression of epigenetic regulatory proteins and histone marks. Novel findings of this study suggest that EGCG, through its antioxidant and epigenetic modulation capacities, has protective effects against arsenic-induced cytotoxicity and fibrogenic changes in kidney epithelial cells.

Association of Combined Per- and Polyfluoroalkyl Substances and Metals with Chronic Kidney Disease

Background: Exposure to environmental pollutants such as metals and Per- and Polyfluoroalkyl Substances (PFAS) has become common and increasingly associated with a decrease in the estimated Glomerular Filtration Rate (eGFR), which is a marker often used to measure chronic kidney disease (CKD). However, there are limited studies involving the use of both eGFR and the urine albumin creatinine ratio (uACR), which are more comprehensive markers to determine the presence of CKD and the complexity of pollutant exposures and response interactions, especially for combined metals and PFAS, which has not been comprehensively elucidated. Objective: This study aims to assess the individual and combined effects of perfluorooctanoic acid (PFOA), perfluorooctanesulfonic acid (PFOS), Cadmium (Cd), Mercury (Hg), and Lead (Pb) exposure on CKD using data from the National Health and Nutritional Examination Survey (NHANES) 2017-2018. Methods: We employed the use of bivariate logistic regression and Bayesian Kernel Machine Regression (BKMR) in our analysis of the data. Results: Logistic regression results revealed a positive association between PFOA and CKD. Our BKMR analysis revealed a non-linear and bi-phasic relationship between the metal exposures and CKD. In our univariate exposure-response function plot, Cd and Hg exhibited a U and N-shaped interaction, which indicated a non-linear and non-additive relationship with both low and high exposures associated with CKD. In addition, the bivariate exposure-response function between two exposures in a mixture revealed that Cd had a U-shaped relationship with CKD at different quantiles of Pb, Hg, PFOA, and PFOS, indicating that both low and high levels of Cd is associated with CKD, implying a non-linear and complex biological interaction. Hg's interaction plot demonstrated a N-shaped association across all quantiles of Cd, with the 75th quantile of Pb and the 50th and 75th quantiles of PFOA and PFOS. Furthermore, the PIP results underscored Cd's consistent association with CKD (PIP = 1.000) followed by Hg's (PIP = 0.9984), then PFOA and PFOS with a closely related PIP of 0.7880 and 0.7604, respectively, and finally Pb (PIP = 0.6940), contributing the least among the five environmental pollutants on CKD, though significant. Conclusions: Our findings revealed that exposure to environmental pollutants, particularly Hg and Cd, are associated with CKD. These findings highlight the need for public health interventions and strategies to mitigate the cumulative effect of PFAS and metal exposure and elucidate the significance of utilizing advanced statistical methods and tools to understand the impact of environmental pollutants on human health. Further research is needed to understand the mechanistic pathways of PFAS and metal-induced kidney injury and CKD, and longitudinal studies are required to ascertain the long-term impact of these environmental exposures.

Association between exposure to multiple metals and stress urinary incontinence in women: a mixture approach

There is limited evidence linking exposure to heavy metals, especially mixed metals, to stress urinary incontinence (SUI). This study aimed to explore the relationship between multiple metals exposure and SUI in women. The data were derived from the National Health and Nutrition Examination Survey (NHANES), 2007-2020. In the study, a total of 13 metals were analyzed in blood and urine. In addition, 5155 adult women were included, of whom 2123 (41.2%) suffered from SUI. The logistic regression model and restricted cubic spline (RCS) were conducted to assess the association of single metal exposure with SUI risk. The Bayesian kernel machine regression (BKMR) and weighted quantile sum (WQS) were used to estimate the combined effect of multiple metals exposure on SUI. First, we observed that blood Pb, Hg and urinary Pb, Cd were positively related to SUI risk, whereas urinary W was inversely related by multivariate logistic regression (all p-FDR < 0.05). Additionally, a significant non-linear relationship between blood Hg and SUI risk was observed by RCS analysis. In the co-exposure models, WQS model showed that exposure to metal mixtures in blood [OR (95%CI) = 1.18 (1.06, 1.31)] and urine [OR (95%CI) = 1.18 (1.03, 1.34)] was positively associated with SUI risk, which was consistent with the results of BKMR model. A potential interaction was identified between Hg and Cd in urine. Hg and Cd were the main contributors to the combined effects. In summary, our study indicates that exposure to heavy metal mixtures may increase SUI risk in women.

Toward a Mechanism-Driven Integrated Framework to Link Human Exposure to Multiple Toxic Metal(loid) Species with Environmental Diseases

The ongoing anthropogenic pollution of the biosphere with As, Cd, Hg and Pb will inevitably result in an increased influx of their corresponding toxic metal(loid) species into the bloodstream of human populations, including children and pregnant women. To delineate whether the measurable concentrations of these inorganic pollutants in the bloodstream are tolerable or implicated in the onset of environmental diseases urgently requires new insight into their dynamic bioinorganic chemistry in the bloodstream-organ system. Owing to the human exposure to multiple toxic metal(loid) species, the mechanism of chronic toxicity of each of these needs to be integrated into a framework to better define the underlying exposure-disease relationship. Accordingly, this review highlights some recent advances into the bioinorganic chemistry of the Cd2+, Hg2+ and CH3Hg+ in blood plasma, red blood cells and target organs and provides a first glimpse of their emerging mechanisms of chronic toxicity. Although many important knowledge gaps remain, it is essential to design experiments with the intent of refining these mechanisms to eventually establish a framework that may allow us to causally link the cumulative exposure of human populations to multiple toxic metal(loid) species with environmental diseases of unknown etiology that do not appear to have a genetic origin. Thus, researchers from a variety of scientific disciplines need to contribute to this interdisciplinary effort to rationally address this public health threat which may require the implementation of stronger regulatory requirements to improve planetary and human health, which are fundamentally intertwined.