Moderate selenium alleviates the pulmonary function impairment induced by cadmium and lead in adults: A population-based study

Essential and Non-Essential Metals and Metalloids and Their Role in Atherosclerosis

Peripheral arterial disease (PAD) is becoming more prevalent in the aging developed world and can have significant functional impacts on patients. There is a recent recognition that environmental toxicants such as circulating metals and metalloids may contribute to the pathogenesis of atherosclerotic disease, but the mechanisms are complex. While the broad toxic biologic effects of metals in human systems have been extensively reviewed, the role of non-essential exposure and essential metal aberrancy in PAD specifically is less frequently discussed. This review of the literature describes current scientific knowledge regarding the individual roles several major metals and metalloids play in atherogenesis and highlights areas where a dearth of data exist. The roles of lead (Pb), arsenic (As), cadmium (Cd), iron (Fe), copper (Cu), selenium (Se) are included. Contemporary outcomes of therapeutic trials aimed at chelation therapy of circulating metals to impact cardiovascular outcomes are also discussed. This review highlights the supported notion of differential metal presence within peripheral plaques themselves, although distinguishing their roles within these plaques requires further illumination.

Selenium alleviates cadmium-induced biological aging acceleration and the potential mediating role of inflammation

Aging and heavy metal pollution are global challenges, and cadmium (Cd) may negatively affect aging. However, effective interventions for Cd toxicity among populations remain insufficient. Selenium (Se) is recognized for its protective effects against heavy metal toxicity and aging. This study utilized data from the National Health and Nutrition Examination Survey (2015-2018) to explore the individual and joint effects of Cd and Se on biological aging acceleration, measured by Klemera-Doubal method biological age acceleration (KDM-BA-Accel) (n = 7119) and Phenotypic age acceleration (PhenoAge-Accel) (n = 7433). Results showed that Cd was positively associated with KDM-BA-Accel (β = 0.57) and PhenoAge-Accel (β = 0.77), while Se had negative associations with both (β values were -4.01 and -5.30, respectively). Nonlinear analyses revealed J-shaped associations for Cd and L-shaped for Se with aging indicators. Moreover, inflammation significantly mediated the Cd-aging and Se-aging relationships. Most importantly, a significant negative interaction between Cd and Se on PhenoAge-Accel (β for interaction = -1.29) suggested an antagonistic effect, particularly among never smokers. Increasing Se content can mitigate the harmful effects of Cd on PhenoAge-Accel were demonstrated through three methods. Specifically, ⅰ) compared to "Cd (-) & Se (-)" group, "Cd (+) & Se (-)" group had β = 0.87, while "Cd (+) & Se (+)" group was non-significant; ⅱ) higher Se content was associated with a lower increase in PhenoAge-Accel as Cd content rose; ⅲ) there were no significant associations between Cd & Se mixture and aging indicators (both p > 0.310). These findings highlight Se supplementation as a potential strategy to counteract Cd-induced aging, offering a new direction for public health interventions in polluted populations.

Association of Maternal Whole Blood Selenium with Cardiac Structure at 4 years of Age:a prospective birth cohort study

BACKGROUND

Currently, little is known about the relationship between maternal blood selenium levels and offspring cardiac structure.

OBJECTIVES

This study aimed to evaluate the association of maternal whole blood selenium levels during early pregnancy with children's cardiac structure at 4 years of age.

METHODS

Using data from the Shanghai Birth Cohort, this study analyzed the data from 956 mother-child pairs. Multiple linear or logistic regressions and restricted cubic spline were used to explore the association of maternal whole blood selenium levels with offspring cardiac structure.

RESULTS

Low maternal selenium levels were associated with increased left ventricular posterior wall thickness at systole (LVPWs) (β = 0.29, 95%CI: 0.06, 0.53), left ventricular posterior wall thickness at diastole (LVPWd) (β = 0.17, 95%CI: 0.01, 0.31), and relative wall thickness (RWT) (β = 0.011, 95%CI: 0.003, 0.019) in male offspring. Moreover, maternal selenium showed a U-shape curve with left ventricular mass index (LVMI) (P for nonlinearity = 0.002), LVPWd (P for nonlinearity = 0.035), IVSd (P for nonlinearity = 0.006) and RWT (P for nonlinearity = 0.013) in male offspring. However, no significant association of structural changes was found in female offspring. Compared with offspring with medium maternal selenium levels, the increased risk of left ventricular hypertrophy (LVH) (OR = 4.14; 95% CI: 1.81, 9.45) was only found in male offspring with lower maternal selenium levels.

CONCLUSIONS

Low maternal selenium levels were associated with cardiac structural changes and higher LVH risk in preschool male offspring, while no correlation was found in female offspring.

Cross-sectional associations between multiple plasma heavy metals and lung function among elderly Chinese

Environmental exposure to heavy metals may adversely affect lung function particularly in the elderly. However, limited data are available directly evaluating the relationship of heavy metal exposures with lung function in Chinese elderly. We aimed to investigate the associations between plasma metals and lung function among Chinese elderly residents. We conducted a cross-sectional study of 308 elderly residents in an industrial area and a non-industrial area in northwest China and estimated the single and combined effects of plasma metals and their interactions with lung functions (forced vital capacity [FVC], forced expiratory volume in 1 s [FEV1], and FEV1/FVC). We analyzed 12 plasma metals and identified 4 metals by lasso regression and BKMR model for further analysis. Bayesian kernel machine regression (BKMR) and quantile-g computation (QG-comp) models estimated four metals that had greater importance in lung function indicators, namely strontium (Sr), chromium (Cr), cobalt (Co) and nickel (Ni). Subgroup analyses were performed based on the resident areas. Both BKMR and QG-comp models showed metal mixtures was positively associated with FEV1/FVC (0.046 [0.017,0.075]) among all participants but of negative association with FVC, and similar results were found among participants in non-industrial area. The subgroup analysis by region showed higher heavy metal levels in industrial areas than non-industrial area. Sr concentrations were lower in non-industrial area, but they had a negative effect on FVC. In conclusion, plasma Sr, Cr, Co, and Ni levels are significant associated with lung function particularly with restrictive ventilatory dysfunction among the Chinese elderly population.

Disentangling the role of selenium in antagonizing the toxicity of arsenic and cadmium

Cadmium (Cd) and inorganic arsenic (As) compounds are considered to be among the major public health hazards. This is due to both the high intrinsic toxicity of these substances and the often difficult to avoid exposure of the general population through contaminated water and food. One proposed method to reduce the toxic effects of As and Cd on animals and humans is the use of selenium (Se). As discussed in our previous article, laboratory studies show that this micronutrient can have a beneficial effect on the detoxification of As and Cd in the body through the formation of non-toxic complexes with these elements, as well as through the antioxidant effects of selenoproteins. New data that have emerged in recent years allow for a clearer description of the interaction between Se and As and Se and Cd. Human studies show that optimal levels of Se can have a beneficial effect in reducing the toxic effects associated with exposure to As or Cd. However, as Se levels in the body increase, the protective effects of Se may be reversed. Recent laboratory studies confirm the antagonistic effects of medium doses of Se toward Cd and As through the formation of nontoxic complexes, antioxidant, anti-inflammatory effects, and induction of pro-survival pathways in cells. In conclusion, Se has a complex effect on As and Cd toxicity, with both benefits and potential risks, depending on the form of Se and its dose as a supplement or the status (level) of this micronutrient in the body.

Persistent organic pollutants among seafood processing workers in West Greenland

The Greenlandic population is highly exposed to persistent organic pollutants (POPs) through the consumption of traditional marine food, including marine mammals. Central to Greenland's economy and cultural identity, the fishing industry employes about 15% of the working population. This study investigated POP exposure, including polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs), and per- and polyfluoroalkyl substances (PFASs), among seafood processing workers at the Greenlandic west coast. We examined determinants for the POPs including age, smoking habits, ethnicity, and working place. Additionally, we explored the association between POPs and the prevalence of asthma, allergy, and lung function. With samples taken during 2016-2018, the study encompassed 382 workers, primarily of Inuit descent (93%), employed across three large factories located in Nuuk, Sisimiut, and Ilulissat, four smaller factories in settlements (Kangaatsiaq, Ikerasaarsuk, Sarfannguaq, Qeqertarsuaq), and four factory trawlers. Data collected include clinical examinations, questionnaires on ethnicity, occupational exposure status, health indicators, and smoking habits, and serum selenium and POP analyses. We used ANCOVA with adjustment for relevant confounders to assess differences in POPs between groups (e.g. ethnic groups and working place), and multiple linear and logistic regressions were used to assess associations between POPs and lung function, allergy and asthma. Significant differences in POPs were observed among ethnic groups; Faroese workers had the highest concentrations of lipophilic POPs (lipPOPs; PCBs and OCPs), while Inuit workers exhibited highest PFASs. All subsequent analyses were focused on the Inuit workers (n = 337). The PFASs were significantly higher in workers at small factories, followed by large factories and trawlers, whereas no differences were seen for lipPOPs. The differences between the working places were most likely due to differences in lifestyle and diet, but occupational exposures cannot be excluded. LipPOP and PFAS concentrations associated positively with selenium, and PFASs positively associated with lung function. However, upon adjustment of selenium, the associations between PFASs and lung function became non-significant and attenuated towards null. No significant associations were found between POPs and the prevalence of asthma or allergy. Compared to the general population in the same area and period, the seafood processing workers exhibited 2-6 times higher POP levels. The higher exposure level among seafood processing workers, as well as the difference across workplaces, underscore the need for further investigation of environmental and occupational sources of POPs in this population. These findings may contribute to future public health strategies and regulatory measures to reduce POP exposure in Arctic populations.

Association between dietary fiber intake and chronic kidney disease in adults with and without hypertension in the United States: a cross-sectional study of NHANES 2009-2020

While previous research has highlighted the potential advantages of increasing dietary fiber intake (DFI) for managing hypertension and chronic kidney disease (CKD), there is a gap in large-scale empirical studies examining the relationship between DFI and CKD among hypertensive and nonhypertensive cohorts independently. This study involved 22,871 participants sourced from the NHANES database spanning 2009 to 2020, who were divided into hypertensive (n = 9,861) and nonhypertensive (n = 13,010) groups. The analysis revealed a significant inverse correlation between DFI and CKD prevalence across the sample after adjusting for various covariates (OR = 0.98, 95% CI: 0.97-0.99, p = 0.001). Within the subset of hypertensive individuals, this inverse association mirrors the findings of the overall sample, indicating that a higher DFI was associated with a reduced occurrence of CKD (OR = 0.97, 95% CI: 0.96-0.99, p < 0.001). However, this correlation was not detected in the nonhypertensive group (OR = 0.99, 95% CI: 0.98-1.01, p = 0.285). The RCS analysis further confirmed a pronounced nonlinear inverse relationship between DFI and CKD prevalence in both the entire cohort and the hypertensive group but not in the nonhypertensive group. Further scrutiny of the hypertensive group revealed that individuals with a higher DFI had 33% lower odds of CKD progression for the moderate risk level and 36% lower odds for the high to very high risk level. Subgroup analyses confirmed the consistency of these relationships across various demographics. In summary, this investigation revealed a significant inverse relationship between DFI and CKD prevalence in US adults with hypertension, a relationship not observed in nonhypertensive individuals.

The correlation between single and mixed trace elements exposure in systemic lupus erythematosus: A case-control study

BACKGROUND

Recent studies have shown an association between trace elements and systemic lupus erythematosus (SLE), but the relationship between trace elements and SLE is still unclear. This study aims to determine the distribution of plasma trace elements in newly diagnosed SLE patients and the association between these essential and toxic element mixtures and SLE.

METHODS

In total, 110 SLE patients and 110 healthy controls were included. Blood samples were collected. 15 plasma trace elements were quantified using an inductively coupled plasma mass spectrometer (ICP-MS). Multivariate logistic regression, restricted cubic spline (RCS), weighted quantile sum (WQS) regression, quantile g-computation (qgcomp), and Bayesian kernel machine regression (BKMR) are used to analyze the association between single and mixed exposure of elements and SLE.

RESULTS

The logistic regression model shows that, plasma lithium (Li) [OR (95 % CI): 1.963 (1.49-2.586)], vanadium (V) [OR (95 % CI): 2.617(1.645-4.166)] and lead (Pb) [OR (95 % CI): 1.603(1.197-2.145)] were positively correlated with SLE, while selenium (Se) [OR (95 % CI): 0.055(0.019-0.157)] and barium (Ba) [OR (95 % CI): 0.792(0.656-0.957)] had been identified as protective factors for SLE. RCS results showed a non-linear correlation between the elements Li, V, Ni, copper, Se, rubidium and SLE. In addition, WQS regression, qgcomp, and BKMR models consistently revealed significant positive effects of plasma Li and Pb on SLE, as well as significant negative effects of plasma Se.

CONCLUSIONS

Exposure to heavy metals such as Li and Pb is significantly positively correlated with SLE, but Se may be protective factors for SLE. In addition, there is a nonlinear correlation between the elements Li and Se and SLE, and there are complex interactions between the elements. In the future, larger populations and prospective studies are needed to confirm these associations.

Association of dietary niacin intake with all-cause and cardiovascular mortality of adult patients with chronic kidney disease in the United States: results from NHANES 1999-2018

Objective

The relationship between dietary niacin intake (DNI) and mortality rates among patients afflicted with chronic kidney disease (CKD) is a subject of debate. Utilizing data derived from the National Health and Nutrition Examination Survey (NHANES), this study adopts a retrospective cohort design with an aim to investigate the association in the American adult patients with CKD.

Methods

A cohort study was conducted in the National Health and Nutrition Examination Survey (NHANES) between 2009 and 2018 that enrolled 6,191 CKD patients aged 20 years and above. We collected data on mortality through 31 December 2018. DNI was measured using a 24-h recall method. The relationship between DNI levels and mortality from all causes and cardiovascular causes was analyzed using weighted Cox proportional hazards models. The Kaplan-Meier (K-M) survival curve was plotted to illustrate these associations.

Results

Following a median monitoring period of 85 months, it was observed that 2,419 individuals (33.08%) succumbed to all causes, whereas cardiovascular-related deaths were recorded for 746 participants (10.45%). When controlling for confounders, an inverse relationship was established between DNI and mortality rates. Specifically, a marginal increase of 1 mg/day in DNI corresponded to a reduced Hazard Ratios (HRs) of 0.993 (0.987, 0.999; p = 0.027) for all-cause mortality and 0.980 (0.969, 0.991; p < 0.001) for cardiovascular mortality. A further stratified analysis by quartiles of DNI, with the lowest quartile serving as the reference, revealed that the highest quartile was associated with HRs of 0.820 (0.697, 0.966) for all-cause mortality and 0.663 (0.465, 0.944) for cardiovascular mortality, both displaying a significant trend (p < 0.001). However, a subdivision of CKD patients by age showed that the protective effects of higher DNI were only confined to individuals aged 60 years and above but not to those under 60 years of age.

Conclusion

A negative correlation between DNI and mortality due to all causes and cardiovascular issues among CKD patients aged 60 and above was revealed based on the datasets; however, this association was not observed in younger individuals under 60. Consequently, enhancing DNI might serve as a beneficial therapeutic strategy specifically for the older CKD demographic.

The correlation between selenium intake and lung function in asthmatic people: a cross-sectional study

Objective

This study aimed to examine the correlation between selenium intake and lung function in asthmatic people.

Methods

A total of 4,541 individuals in the US National Health and Nutrition Examination Survey (NHANES) were included in this study. Multivariate linear regression, variance inflation factor, restricted cubic splines and quantile regression were used to analyze the relationship between Se intake and lung function. We divided selenium intake into four levels based on quartiles: Q1: Se ≤ 76.75 mcg/d; Q2: 76.75-105.1 mcg/d; Q3: 105.1-137.65 mcg/d; and Q4: Se ≥137.65 mcg/d.

Results

Asthma was negatively associated with the Ratio of Forced Expiratory Volume 1st Second to Forced Vital Capacity (FEV1/FVC) (β = -0.04, 95% CI: -0.06 to -0.02) and FEV1 (β = -215, 95% CI: -340 to -90). Se intake was positively associated with Forced Expiratory Volume 1st Second (FEV1) (β =3.30 95% CI: 2.60 to 4.00) and Forced Vital Capacity (FVC) (β =4.30, 95% CI: 3.50 to 5.10). In asthmatic individuals, the positive effects of Se intake on FVC were enhanced with increasing Se intake, while the positive effects of Se intake on FEV1 varied less dramatically. High Se intake (Q4 level, above 137.65 mcg/d) improved FVC (β = 353, 95% CI: 80 to 626) and FEV1 (β = 543, 95% CI: 118 to 969) in asthmatic patients compared to low Se intake (Q1 level, below 76.75 mcg/d). At the Q2 level (76.75-105.1 mcg/d) and Q4 level (Se ≥137.65 mcg/d) of Se intake, the correlation between FEV1 and asthma disappeared.

Conclusion

Our research has revealed a positive correlation between selenium intake and lung function in asthma patients and the strength of this positive correlation is related to the amount of selenium intake. We recommend that asthma patients consume 137.65 mcg to 200 mcg of selenium daily to improve pulmonary function while avoiding the adverse effects of selenium on the human body.

Effects of selenium-cadmium co-enriched Cardamine hupingshanensis on bone damage in mice

Selenium (Se) and cadmium (Cd) usually co-existed in soils, especially in areas with Se-rich soils in China. The potential health consequences for the local populations consuming foods rich in Se and Cd are unknown. Cardamine hupingshanensis (HUP) is Se and Cd hyperaccumulator plant that could be an ideal natural product to assess the protective effects of endogenous Se against endogenous Cd-caused bone damage. Male C57BL/6 mice were fed 5.22 mg/kg cadmium chloride (CdCl2) (Cd 3.2 mg/kg body weight (BW)), or HUP solutions containing Cd 3.2 mg/kg BW and Se 0.15, 0.29 or 0.50 mg/kg BW (corresponding to the HUP0, HUP1 and HUP2 groups) interventions. Se-enriched HUP1 and HUP2 significantly decreased Cd-induced femur microstructure damage and regulated serum bone osteoclastic marker levels and osteogenesis-related genes. In addition, endogenous Se significantly decreased kidney fibroblast growth factor 23 (FGF23) protein expression and serum parathyroid hormone (PTH) levels, and raised serum calcitriol (1,25(OH)2D3). Furthermore, Se also regulated gut microbiota involved in skeletal metabolism disorder. In conclusion, endogenous Se, especially with higher doses (the HUP2 group), positively affects bone formation and resorption by mitigating the damaging effects of endogenous Cd via the modulation of renal FGF23 expression, circulating 1,25(OH)2D3 and PTH and gut microbiota composition.

Moderate selenium mitigates hand grip strength impairment associated with elevated blood cadmium and lead levels in middle-aged and elderly individuals: insights from NHANES 2011-2014

Background: Selenium (Se) has been reported to have an antagonistic effect on heavy metals in animals. Nevertheless, there is a lack of epidemiological research examining whether Se can mitigate the adverse effects of cadmium (Cd) and lead (Pb) on hand grip strength (HGS) in middle-aged and elderly individuals. Methods: This study used data from the 2011-2014 National Health and Nutrition Examination Survey (NHANES). HGS measurements were conducted by trained examiners with a dynamometer. Concentrations of Se, Cd, and Pb in blood were determined via inductively coupled plasma mass spectrometry. We employed linear regression, restricted cubic splines, and quantile g-computation (qgcomp) to assess individual and combined associations between heavy metals and HGS. The study also explored the potential influence of Se on these associations. Results: In both individual metal and multi-metal models adjusted for confounders, general linear regression showed Se's positive association with HGS, while Cd and Pb inversely related to it. At varying Se-Cd and Se-Pb concentrations, high Se relative to low Se can attenuate Cd and Pb's HGS impact. An inverted U-shaped correlation exists between Se and both maximum and combined HGS, with Se's benefit plateauing beyond approximately 200 μg/L. Stratified analysis by Se quartiles reveals Cd and Pb's adverse HGS effects diminishing as Se levels increase. Qgcomp regression analysis detected Se alleviating HGS damage from combined Cd and Pb exposure. Subsequent subgroup analyses identified the sensitivity of women, the elderly, and those at risk of diabetes to HGS impairment caused by heavy metals, with moderate Se supplementation beneficial in mitigating this effect. In the population at risk for diabetes, the protective role of Se against heavy metal toxicity-induced HGS reduction is inhibited, suggesting that diabetic individuals should particularly avoid heavy metal-induced handgrip impairment. Conclusion: Blood Cd and Pb levels are negatively correlated with HGS. Se can mitigate this negative impact, but its effectiveness plateaus beyond 200 μg/L. Women, the elderly, and those at risk of diabetes are more vulnerable to HGS damage from heavy metals. While Se supplementation can help, its protective effect is limited in high diabetes risk groups.