Blood Cadmium Levels Research Articles

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.

Combined Effects of Environmental Metals and Physiological Stress on Lipid Dysregulation.

Cardiovascular diseases (CVD) are a leading cause of mortality worldwide, influenced by genetic, environmental, and behavioral factors. This study examines the relationship between heavy metal exposure, chronic physiological stress (allostatic load), and lipid profiles, which are markers of CVD risk, using data from the National Health and Nutrition Examination Survey (NHANES) 2017-2018. We utilized structural equation modeling (SEM) to explore the associations between blood levels of lead, cadmium, allostatic load (AL), and lipid measures (low-density lipoprotein (LDL), high-density lipoprotein (HDL), and triglycerides). The AL index was derived from cardiovascular, inflammatory, and metabolic biomarkers and categorized into quartiles to identify high-risk individuals, with an index out of 10 subsequently developed. The SEM analysis revealed that both heavy metal exposure and allostatic load are significantly associated with lipid profiles. Higher levels of lead and cadmium were associated with increased LDL and triglycerides, while higher AL scores were linked to increased LDL and triglycerides and decreased HDL levels. Age was also a significant factor, showing positive correlations with LDL and triglycerides, and a negative correlation with HDL. This study underscores the multifactorial nature of CVD, highlighting the combined impact of environmental pollutants and physiological stress on lipid dysregulation. These findings suggest the need for integrated public health strategies that address both environmental exposures and chronic stress to mitigate cardiovascular risk. Further research is warranted to explore the underlying mechanisms and develop targeted interventions.

Cadmium (Third Edition) (Chemicals and Contaminants).

Exposure to cadmium tends to be higher in Japan than in other countries due to the wide spreading of ore deposits and many mines throughout Japan. The proximal tubule of the kidney is recognized as the most susceptible site to be affected by cadmium exposure. Food Safety Commission of Japan (FSCJ) considered it appropriate to investigate studies of the effects of cadmium intake on renal proximal tubular function using urinary β2-microglobulin concentration of 1,000 μg/g creatinine as a criterion for the dysfunction. Based on these epidemiological studies, FSCJ established a tolerable weekly intake (TWI) of 7 µg/kg bw per week for cadmium. This value is derived from the results of actual dietary surveys and urinary β2-microglobulin concentrations in Japan, and not from the results of application of blood or urinary cadmium levels to theoretical models. Therefore, no uncertainty factor is required. The estimated dietary intake of cadmium in 2022 was 2.03 µg/kg bw per week, approximately 30% of the TWI of 7 µg/kg bw per week. Therefore, it is unlikely that dietary cadmium intake in the general Japanese population would cause adverse health effects.

Association of blood cadmium, lead, and mercury with anxiety: a cross-sectional study from NHANES 2007-2012.

The purpose of this paper is to explore the relationship between blood levels of cadmium, lead, and mercury and anxiety in American adults. Blood metals and self-reported anxiety days were extracted from laboratory data and questionnaire data, respectively, using NHANES data from 2007-2012. Weighted logistic regression was used to assess the relationship between cadmium, lead and mercury with anxiety. Restricted cubic spline was used to visualize the non-linear relationship between metal concentrations and anxiety. Weighted quantile sum (WQS) regression was used to investigate the effect of combined exposure to the three metals on anxiety. The prevalence of anxiety in adults was 26.0%. After adjusting for potential confounding variables, cadmium levels in the highest quartile (Q4) were associated with a higher risk of anxiety compared to the lowest quartile (Q1) (OR = 1.279, 95% CI: 1.113-1.471, p < 0.01). Restricted cubic spline analysis indicated a positive association between blood cadmium levels and anxiety. Furthermore, co-exposure to multiple heavy metals was positively associated with anxiety risk (WQS positive: OR = 1.068, 95% CI: 1.016-1.160, p < 0.05), with cadmium contributing the most to the overall mixture effect. Compared to the Light RPA, the Vigorous/Moderate RPA group had a relatively low risk of anxiety after cadmium exposure. High levels of blood cadmium are positively associated with the development of anxiety disorders, which needs to be further verified in future studies.

Mixture analysis of associations between environmental and workplace toxins and liver damage and telomere length, stratified by race/ethnicity

This study aimed to identify the worst “bad actors” in mixtures of pollutants contributing to liver damage and shorter telomeres in the U.S. population, using Weighted Quantile Sum (WQS) modeling with stratification by race/ethnicity. We conducted a comprehensive cross-sectional analysis of mixtures of pollutants in National Health and Nutrition Examination Survey datasets: a) 33,979 adults with blood levels of cadmium (Cd), lead (Pb), and mercury, including subsets with measurements of per-/polyfluoroalkyl substances (PFAS), and polychlorinated biphenyls (PCBs)/polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs); and b) 7360 adults with measurements of telomeres, Cd, and Pb. Multivariable-adjusted WQS regression examined associations between WQS mixture indices and liver injury [alanine aminotransferase (ALT)-elevation], advanced liver-fibrosis (LF), and telomere length. WQSmetal indices were associated with advanced-LF in all racial/ethnic groups. The top contributor was Cd in the total population and in non-Hispanic Whites (NHW), while Pb was the top contributor in non-Hispanic Blacks (NHB). The WQSmetal-PCB-PCDD/F index was associated with ALT-elevation, with PCB126, Cd and Pb as main contributors; the odds ratio (OR) per decile was 1.50 (95%CI, 1.26-1.78), while the OR per decile of the WQSmetal-PFAS index was 1.03 (95%CI, 0.98-1.05), not significant. WQSmetal indices were associated with shorter telomeres. Cd was main contributor associated with advanced-LF in NHW, while Pb was the major bad actor in NHB, suggesting that NHB may be especially susceptible to Pb toxicity. Metals were associated with shorter telomeres. Metal and PCB/PCDD/F mixtures were associated with ALT-elevation. Heavy metals and organic chemicals may contribute to liver-related morbidity and healthcare disparities.

Is Kidney Stone Associated with Thyroid Disease? The United States National Health and Nutrition Examination Survey 2007-2018.

Kidney stones and thyroid disease are two common diseases in the general population, with multiple common risk factors. The associations between kidney stones and thyroid disease are unclear. This study aims to assess the association between 'once had a thyroid disease' and the odds of kidney stones. Adult participants from the National Health and Nutrition Examination Survey (NHANES) 2007-2018 with reliable kidney stone and thyroid disease data were included. Adjusting for age, gender, race, education level, and marital status, diabetes, hypertension, gout, angina pectoris, stroke, and asthma, logistic regression was used to examine the relationship between kidney stones and thyroid illness. Using stratified analysis, the association between thyroid illness and kidney stones was investigated further. Among the participants, 4.9% had kidney stones, and 10.1% had thyroid disease. Kidney stone was associated with thyroid disease (OR=1.441, (95% CI:1.294-1.604), p <0.01), which remained significant (OR=1.166, (95% CI:1.041-1.305), p <0.01) after adjustments with age, gender, race, education level and marital status, diabetes, hypertension, gout, angina pectoris, stroke, and asthma. Stratified by blood lead, blood cadmium, and blood urea nitrogen levels in the human body, the odds of kidney stones still increased with once having a previous thyroid disease. In this large nationally representative survey over 10 years, kidney stone was strongly associated with thyroid disease. In this cross-sectional study, we explored the association between thyroid disease and kidney stones, which may help clinicians intervene in them early.

Association between cadmium exposure and serum neurofilament light chain levels: A nationwide population-based survey

BackgroundAlthough cadmium exposure had been demonstrated to be toxic to the nervous system, little was known about the link between cadmium exposure and axonal injury. Therefore, the present study aimed to reveal whether there was any correlation between blood cadmium and serum neurofilament light chain (NfL) levels in the general population. MethodsThis study included 1040 participants with a median (IQR) age of 47 (35−60) years from the 2013–2014 National Health and Nutrition Examination Survey. Serum NfL levels were measured through immunoassay, and whole blood cadmium concentrations were detected by means of inductively coupled plasma mass spectrometry. Linear regression and restricted cubic spline model was applied to analyze the significance of relationship between blood cadmium and serum NfL levels. ResultsIn the full adjusted model, blood cadmium levels were found to be positively associated with serum NfL levels (Q4 vs Q1, β = 3.35, 95 %CI: 0.41, 6.30, p for trend = 0.014). A potential linear positive dose-effect relationship was discovered between blood cadmium and serum NfL levels (p for non-linearity = 0.15). According to the result of stratified analysis, the significant positive relationship between blood cadmium and serum NfL levels was present only in the population of middle-aged and older adults. ConclusionThe present study suggested a positive association between blood cadmium and serum NfL levels in the general US population.

Evaluation of Lead and Cadmium Levels in Individuals Exposed to Cement Dust

Background: Heavy metals such as lead and cadmium, which are present in cement dust, are elements with a density of more than 5 g/cm3 that are harmful to both the environment and living creatures. This study was set out to evaluate levels of lead and cadmium in individuals exposed to cement dust in Nnewi metropolis. Study Design: This case-control study was carried out among male and female workers in cement depots in Nnewi metropolis who were selected by simple random sampling. Methods: Thirty-five individuals exposed to cement dust defined as test participants and thirty-five individuals not exposed to cement dust defined as control participants within the age range of 18 and 51 years were selected into this study. Test participants were sub-grouped based on years of exposure to cement dust into 3 years and below, 4 to 6 years and 7 years and above. Five millilitres of whole blood was collected from each selected participant and levels of lead and cadmium were determined using atomic absorption spectrometry. Data were analysed using Independent Student’s T-test and ANOVA with least significant difference post hoc. Data was presented as mean ± standard deviation and significance level was taken at p&lt; 0.05. Results: The blood levels of lead and cadmium in test participants were significantly higher than blood levels in control participants. The lead levels were significantly higher in test participants exposed to cement dust for 7 years and above than in test participants exposed to cement dust between 4 to 6 years and test participants exposed to cement dust for 3 years and below (p&lt;0.001). There was no significant difference in serum levels of cadmium between test participants exposed to cement dust for 3 years and below, test participants exposed to cement dust between 4 years to 6 years and test participants exposed to cement dust for 7 years and above (p&gt;0.05). Conclusion: Occupational exposure to cement dust causes high blood levels of lead and cadmium in the body and this accumulation is dangerous to health.

Evaluating the Impact of Airborne Fine Particulate Matter and Heavy Metals on Oxidative Stress via Vitamin Supplementation.

This cross-sectional study aimed to assess the interrelationships between PM2.5 exposure, heavy metal concentrations, and oxidative stress indicators, while evaluating the impact of antioxidant intake, such as vitamins, on these associations. PM2.5 exposure assessments were conducted using portable sensor-based monitors; biomarker analyses for heavy metals and oxidative stress were performed in 114 non-smoking adults. We observed that personal or ambient PM2.5 exposure levels were not associated with increased levels of heavy metals in blood and urine, nor with oxidative stress levels in urine. However, the concentrations of cadmium and lead in blood, and those of chromium and nickel in urine, were significantly associated with the urinary malondialdehyde (MDA) concentration. Additionally, increases in blood cadmium, urinary chromium, and nickel levels were significantly associated with higher urinary MDA concentrations in the non-vitamin-supplement group, but this trend was not observed in the regular vitamin supplement group. Our findings suggest that a regular intake of vitamin supplements might modulate the relationship between heavy metal exposure and oxidative stress, indicating potential protective effects against oxidative damage induced by PM2.5 and heavy metals. This study highlights the complexity of environmental pollutant exposure and its impact on human health, emphasizing the need for further research to elucidate the underlying mechanisms and explore potential protective strategies.

A machine learning model predicts stroke associated with blood cadmium level

Stroke is the leading cause of death and disability worldwide. Cadmium is a prevalent environmental toxicant that may contribute to cardiovascular disease, including stroke. We aimed to build an effective and interpretable machine learning (ML) model that links blood cadmium to the identification of stroke. Our data exploring the association between blood cadmium and stroke came from the National Health and Nutrition Examination Survey (NHANES, 2013–2014). In total, 2664 participants were eligible for this study. We divided these data into a training set (80%) and a test set (20%). To analyze the relationship between blood cadmium and stroke, a multivariate logistic regression analysis was performed. We constructed and tested five ML algorithms including K-nearest neighbor (KNN), decision tree (DT), logistic regression (LR), multilayer perceptron (MLP), and random forest (RF). The best-performing model was selected to identify stroke in US adults. Finally, the features were interpreted using the Shapley Additive exPlanations (SHAP) tool. In the total population, participants in the second, third, and fourth quartiles had an odds ratio of 1.32 (95% CI 0.55, 3.14), 1.65 (95% CI 0.71, 3.83), and 2.67 (95% CI 1.10, 6.49) for stroke compared with the lowest reference group for blood cadmium, respectively. This blood cadmium-based LR approach demonstrated the greatest performance in identifying stroke (area under the operator curve: 0.800, accuracy: 0.966). Employing interpretable methods, we found blood cadmium to be a notable contributor to the predictive model. We found that blood cadmium was positively correlated with stroke risk and that stroke risk from cadmium exposure could be effectively predicted by using ML modeling.

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

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

Neural network approach to predict the association between blood cadmium levels and hypertension

Hypertension is a global health concern and a major risk factor for cardiovascular disease. Early prevention and management based on risk prediction is a principal goal of many national health policies. We studied the relationship between blood cadmium concentrations and hypertension and developed an artificial neural network (ANN) that predicts hypertension risk. For this study, we utilized data from the Korean National Health and Nutrition Examination Survey (KNHANES), conducted between 2008 and 2013, which is a nationwide population-based survey of the Korean population. We extracted and analyzed sociodemographic characteristics, serum cadmium levels, and blood pressure information from a sample of adults aged 19 years and above (n=11,530). After adjusting for sociodemographic factors, cadmium levels were positively associated with the risk of hypertension (p &lt; 0.001). Groups with high cadmium levels significantly increased the odds ratios for hypertension compared to the lowest tertile. An ANN model in which sociodemographic factors and the blood concentration of cadmium were the principal inputs yielded a predictive accuracy of 0.773 and an area under the curve of 0.823. ANNs with appropriate inputs can identify population subgroups at high risk of developing hypertension and will aid in the formulation of policies that prevent disease.

Blood cadmium level as a risk factor for chronic pain: NHANES database 1999-2004.

The escalating prevalence of chronic pain poses a substantial socio-economic burden. Chronic pain primarily stems from musculoskeletal and nervous system impairments. Given cadmium's known toxicity to these systems, our study sought to investigate the correlation between blood cadmium levels and chronic pain. The cross-sectional study was conducted from the National Health and Nutrition Examination Survey (NHANES, 1999-2004), and comprised US adults who participated in a chronic pain interview. We employed logistic regression models and smooth curve fitting to elucidate the relationship between blood cadmium levels and chronic pain. Our findings revealed a linear association between blood cadmium levels and chronic pain. Compared to the lower blood cadmium tertile 1 (<0.3 ug/dL), the adjusted odds ratios (ORs) for tertile 2 (0.3-0.4 ug/dL), and tertile 3 (≥0.5 ug/dL), were 1.11 (0.96-1.29) and 1.2 (1.03-1.39), respectively. Sensitivity analyses corroborated these results. Elevated levels of blood cadmium are associated with a heightened risk of chronic pain among adults in the United States. Mitigating cadmium exposure could potentially decrease the risk of chronic pain, thereby enhancing strategies for chronic pain prevention and management.

Association of dietary selenium intake and all-cause mortality of Parkinson’s disease and its interaction with blood cadmium level: a retrospective cohort study

BackgroundParkinson’s disease (PD) is a slowly progressive neurodegenerating disease that may eventually lead to disabling condition and pose a threat to the health of aging populations. This study aimed to explore the association of two potential risk factors, selenium and cadmium, with the prognosis of Parkinson’s disease as well as their interaction effect.MethodsData were obtained from the National Health and Nutrition Examination Survey (NHANES) 2005–2006 to 2015–2016 and National Death Index (NDI). Participants were classified as Parkinson’s patients by self-reported anti-Parkinson medications usage. Cox regression models and restricted cubic spline models were applied to evaluate the association between PD mortality and selenium intake level as well as blood cadmium level. Subgroup analysis was also conducted to explore the interaction between them.ResultsA total of 184 individuals were included. In full adjusted cox regression model (adjusted for age, gender, race, hypertension, pesticide exposure, smoking status and caffeine intake), compared with participants with low selenium intake, those with normal selenium intake level were significantly associated with less risk of death (95%CI: 0.18–0.76, P = 0.005) while no significant association was found between low selenium intake group and high selenium group (95%CI: 0.16–1.20, P = 0.112). Restricted cubic spline model indicated a nonlinear relationship between selenium intake and PD mortality (P for nonlinearity = 0.050). The association between PD mortality and blood cadmium level was not significant (95%CI: 0.19–5.57, P = 0.112). However, the interaction term of selenium intake and blood cadmium showed significance in the cox model (P for interaction = 0.048). Subgroup analysis showed that the significant protective effect of selenium intake existed in populations with high blood cadmium but not in populations with low blood cadmium.ConclusionModerate increase of selenium intake had a protective effect on PD mortality especially in high blood cadmium populations.

Association between breakfast skipping and blood levels of lead and cadmium in children and adolescents aged 6–17 years: Results from the National Health and Nutrition Examination Survey 2013–2018

IntroductionPrevious research suggests that fasting increases lead absorption in the gastrointestinal tract, and that regularly eating meals may reduce blood lead. However, there is insufficient evidence linking breakfast status and blood-metal levels in children. We assessed the cross-sectional association between breakfast consumption status and children and adolescent’s blood levels of lead and cadmium. We also explored blood hemoglobin, serum ferritin, and age group as potential effect modifiers of these associations. MethodsThis analysis included children and adolescents aged 6–17 years who participated in the National Health and Nutrition Examination Survey (NHANES) cycles 2013–2018 with complete data on breakfast consumption status (consumers vs. skippers), blood metals, and covariates (N=3722). Blood metal variables were log-transformed. Crude and covariate-adjusted, survey-weighted linear regression models were conducted for each blood metal outcome. Potential effect modification was explored using stratification. ResultsOverall fewer participants reported skipping breakfast (n=719) than eating breakfast (n=3003). Mean (SE) concentrations of blood lead and cadmium (µg/L) were 0.63 (0.01) µg/dL and 0.13 (0.00) µg/L, respectively. Children and adolescents who skipped breakfast were more likely to be female (51.2%), older (mean 12.2 years, SE = 0.1), have a higher body mass index (mean 22.8 kg/m2, SE = 0.2), and a lower income-poverty ratio (mean 1.7, SE = 0.1) than breakfast consumers. No associations between breakfast consumption and any of the blood metals were found. When stratified by age (≤ 10, 11–13, and 14–17 years), children aged 11–13 years who consumed breakfast had lower log-transformed blood lead levels [β = −0.14 µg/L; 95% CI: (-0.25, −0.03)] compared to children of the same age who skipped breakfast. ConclusionChildren 11–13 years-old who were breakfast consumers had lower blood lead levels compared to children of the same age who skipped breakfast. Our results support that encouraging breakfast consumption among school-age children may contribute to lower blood lead levels.

Blood Cadmium Level Is a Marker of Cancer Risk in Men.

Cadmium (Cd) is a known carcinogen, but its impact on cancer risk at lower concentrations is poorly understood. Previous studies on Cd and cancer risk in men show inconsistent results, prompting further investigation. A prospective cohort study involving 2956 men was conducted. Blood Cd levels were measured, and participants were followed for 78 months to assess cancer incidence. Men with high blood Cd levels (>0.71 µg/L) had a significantly increased risk of cancer compared to those with low levels (<0.19 µg/L) (HR 3.42, p < 0.001), particularly among non-smokers (HR 3.74, p = 0.003), individuals aged < 60 years (HR 2.79, p = 0.017), and ≥60 (HR 4.63, p = 0.004). The influence of smoking on cancer risk based on Cd levels was not significant in this study. Blood Cd levels may influence cancer risk in men, emphasizing the importance of minimizing Cd exposure to reduce risk. Confirmation of these results in other populations is essential for effective preventive measures against Cd-related cancers.

Antioxidant Effects of Whey Protein as a Dietary Supplement to Alleviate Cadmium-Induced Oxidative Stress in Male Wistar Rats

The liquid whey is a byproduct produced during cheese making. Cadmium is a highly hazardous heavy metal with cumulative toxic effects. The present research work was done to clarify the possible role of whey proteins in alleviating cadmium-induced oxidative stress. The used rats were allotted equally and randomly into three experimental groups; untreated control, cadmium-exposed, and cadmium-exposed and whey protein-administered groups. The biochemical and haematological assays of rats exposed to cadmium (group 2) manifested significant alterations compared to those of untreated control animals. Concerning the biochemical serum profile, group 3 animals showed relatively increased levels of total proteins, significant increments of total thiols, glutathione, total antioxidant capacity (TAC), and catalase, and significant decrements in the levels of blood cadmium, alanine transferase (ALT), aspartate transferase (AST), alkaline phosphatase (ALP), creatinine, urea, bilirubin, hydrogen peroxide (H2O2), and malondialdehyde (MDA) compared to the animals exposed to cadmium (group 2). Homogenates of liver and kidney tissues obtained from group 3 animals demonstrated similar results to that revealed by the serum assay. It was concluded that whey proteins as a dietary supplement can offer potential antioxidant properties that enable these supplementary proteins to alleviate cadmium-induced oxidative stress.

Associations of Heavy Metals with Cognitive Function: An Epigenome-Wide View of DNA Methylation and Mediation Analysis.

Exposure to heavy metals has been reported to be associated with impaired cognitive function, but the underlying mechanisms remain unclear. This pilot study aimed to identify key heavy metal elements associated with cognitive function and further explore the potential mediating role of metal-related DNA methylation. Blood levels of arsenic, cadmium, lead, copper, manganese, and zinc and genome-wide DNA methylations were separately detected in peripheral blood in 155 older adults. Cognitive function was evaluated using the Mini-Mental State Examination (MMSE). Least absolute shrinkage and selection operator penalized regression and Bayesian kernel machine regression were used to identify metals associated with cognitive function. An epigenome-wide association study examined the DNA methylation profile of the identified metal, and mediation analysis investigated its mediating role. The MMSE scores showed a significant decrease of 1.61 (95% confidence interval [CI]: -2.64, -0.59) with each 1 standard deviation increase in ln-transformed arsenic level; this association was significant in multiple-metal models and dominated the overall negative effect of 6 heavy metal mixture on cognitive function. Seventy-three differentially methylated positions were associated with blood arsenic (p < 1.0 × 10-5). The methylation levels at cg05226051 (annotated to TDRD3) and cg18886932 (annotated to GAL3ST3) mediated 24.8% and 25.5% of the association between blood arsenic and cognitive function, respectively (all p < 0.05). Blood arsenic levels displayed a negative association with the cognitive function of older adults. This finding shows that arsenic-related DNA methylation alterations are critical partial mediators that may serve as potential biomarkers for further mechanism-related studies. ANN NEUROL 2024;96:87-98.

Exposure to low levels of heavy metals and chronic kidney disease in the US population: A cross sectional study.

Exposure to heavy metals (cadmium, mercury, and lead) has been linked with adverse health outcomes, especially their nephrotoxic effects at high levels of exposure. We conducted a replication study to examine the association of low-level heavy metal exposure and chronic kidney disease (CKD) using a larger NHANES data set compared to previous studies. The large cross-sectional study comprised 5,175 CKD cases out of 55677 participants aged 20-85 years from the 1999-2020 National Health and Nutrition Examination Survey [NHANES]. Logistic regression analysis was applied to estimate the associations between CKD and heavy metals [Cd, Pb, Hg] measured as categorical variables after adjusting with age, race, gender, socioeconomic status, hypertension, diabetes mellitus and blood cotinine level as smoking status. Compared to the lowest quartile of blood Cd, exposures to the 2nd, 3rd and 4th quartiles of blood Cd were statistically significantly associated with higher odds of CKD after adjustment for blood Pb and Hg, with OR = 1.79, [95% CI; 1.55-2.07, p<0.0001], OR = 2.17, [95% CI; 1.88-2.51, p<0.0001] and OR = 1.52, [95% CI; 1.30-1.76, p<0.0001] respectively. The 2nd, 3rd and 4th quartiles of blood Cd remained statistically significantly associated with higher odds of CKD after adjustment for blood cotinine level, with OR = 2.06, [95% CI; 1.80-2.36, p<0.0001], OR = 3.18, [95% CI; 2.79-3.63, p<0.0001] and OR = 5.54, [95% CI; 4.82-6.37, p<0.0001] respectively. Exposure to blood Pb was statistically significantly associated with higher odds of CKD in the 2nd, 3rd and 4th quartile groups, after adjustment for all co-variates (ag, gender, race, socio-economic status, hypertension, diabetes mellitus, blood cadmium, mercury, and cotinine levels) in all the four models. Blood Hg level was statistically significantly associated with lower odds of CKD in the 2nd quartile group in model 2, 3rd quartile group in model 1, 2 and 3, and the 4th quartile group in all the four models. Our findings showed that low blood levels of Cd and Pb were associated with higher odds of CKD while low blood levels of Hg were associated with lower odds of CKD in the US adult population. However, temporal association cannot be determined as it is a cross sectional study.

Association between Suicidal Ideation and Blood Cadmium Levels Based on the 3rd to 7th Korea National Health and Nutrition Examination Surveys

Background: This study aimed to determine the association between blood cadmium levels and suicidal ideation.Methods: Using data from the 3rd to 7th Korea National Health and Nutrition Examination Surveys, the geometric mean of blood cadmium levels according to suicidal ideation was compared using multiple linear regression analyses in male and female adults. The frequency of suicidal ideation according to the blood cadmium levels was also compared using multiple logistic regression models.Results: In total, 6,877 men and 6,698 women were included in the study. When adjusting for all potential confounding factors, the geometric mean of blood cadmium levels was significantly higher in participants with suicidal ideation than in those without suicidal ideation in both men (0.92 ng/ml [95% confidence interval 0.87∼0.97 ng/ml] vs. 0.86 ng/ml [0.84∼0.88 ng/ml]; p=.026) and women (1.05 ng/ml [95% confidence interval 1.01∼1.10 ng/ml] vs. 0.99 ng/ml [0.98∼1.02 ng/ml]; p=.006). After adjusting for potential confounders, the frequency of suicidal ideation significantly increased as blood cadmium levels increased in men (p for trend=.014) and women (p for trend=.034).Conclusions: Results revealed an association between blood cadmium levels and suicidal ideation in Korean adults.