Selenium and outcome in heart failure

Cascade targeting selenium nanoparticles-loaded hydrogel microspheres for multifaceted antioxidant defense in osteoarthritis

Selenium (Se) deficiency is a critical factor contributing to the imbalance of redox homeostasis in chondrocytes and the progression of osteoarthritis (OA). However, traditional selenium supplements face challenges such as a narrow therapeutic window and lack of targeting. To address this, we designed hyaluronic acid (HA)-modified selenium nanoparticles (HA-SeNPs) and developed a cascade-targeted delivery system (HA-SeNPs@AHAMA-HMs) based on a nano-micron combined strategy. The system involves loading HA-SeNPs into aldehyde-functionalized hydrogel microspheres prepared via microfluidic technology. Through Schiff base reactions between the aldehyde groups of the microspheres and amino groups of the cartilage, the system selectively adheres to the surface of damaged cartilage, achieving micron-scale targeting while continuously releasing HA-SeNPs. Then, HA-SeNPs achieve nanoscale targeting by binding to CD44, which is highly expressed on OA chondrocyte membranes, via their HA surface. Once taken up by the cells, HA-SeNPs exert their effects by directly scavenging ROS and promoting selenoprotein synthesis through the generation of selenite, forming a multifaceted antioxidant defense system. This effectively alleviates oxidative stress and optimizes mitochondrial function. In vivo and in vitro results demonstrated that this system significantly improved the oxidative phosphorylation pathway associated with mitochondrial function, which markedly reduced joint space narrowing and cartilage matrix degradation, and delayed the progression of OA. In summary, this study suggests that the cascade-targeting hydrogel microspheres designed and constructed based on a nano-micron combined strategy represent a promising prospective approach for precise Se supplementation and OA treatment.

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.

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.

Trace elements: Clinical perspectives in the critically ill

Trace elements are required in minute quantities in the diet but play a vital role in a wide variety of functions, such as co-factors in antioxidant reactions and normal immune function to DNA and protein synthesis and skeletal and tissue remodelling and repair. Critically ill patients are at risk of trace element deficiency or excess, due to changes in intake, absorption, metabolism or excretion. Deficiency or excess can lead to a wide range of cellular and organ dysfunction that may be seen in patients with an acute or critical illness, including cardiomyopathy, impaired glucose tolerance and reduced oxygen delivery. In addition, various diseases, such as systemic inflammation and renal and intestinal failure, and intensive care treatments, such as parenteral nutrition, renal replacement therapy and diuretics, can increase the likelihood of deficient or excessive amounts of micronutrient levels. This narrative review discusses sources and normal physiology of trace element handling and how this may be impaired in critically ill patients. It then discusses various conditions seen in critically ill patients that may be caused or exacerbated by abnormal trace element status and the current evidence around whether supplementation is of benefit in particular critical illnesses.

Predictors of Plasma Selenium Levels and Association with Prognosis in Outpatients with Heart Failure: a 36-Month Prospective Cohort Study

Selenium plays a role in the context of heart failure (HF), but still, there are gaps regarding the factors associated with selenium status, as well as its association with the prognosis of HF. We aimed to investigate predictors of plasma selenium and its association with hospitalization and all-cause mortality. This prospective cohort study included 80 outpatients with HF. Non-elective hospitalization and all-cause mortality were assessed during 36 months of follow-up. The associations between plasma selenium, dietary selenium intake, and sociodemographic, clinical, and biochemical parameters were evaluated by a multiple linear regression model. The risk of these clinical outcomes was assessed with multivariate Cox regression and cubic splines analysis. Albumin (β = 0.113, p < 0.001; R2 = 0.291) and triacylglycerol levels (β = 0.0002, p < 0.021, R2 = 0.376) were predictors of plasma selenium levels. No significant associations were found between dietary selenium intake and plasma selenium tertiles with hospitalization and all-cause mortality (all p > 0.05). The cubic splines analysis revealed that both low and high selenium concentrations influence these outcomes. The predictors of plasma selenium were related to the clinical conditions of HF. Selenium in plasma should be interpreted cautiously, considering that low and high levels may be associated with risks of adverse outcomes in HF.

Role of selenium in the pathophysiology of cardiorenal anaemia syndrome

Chronic kidney disease (CKD) and cardiovascular disease (CVD) have multiple bidirectional mechanisms, and anaemia is one of the critical factors that are associated with the progression of the two disorders [referred to as cardiorenal anaemia syndrome (CRAS)]. Several lines of evidence indicate that CRAS confers a worse prognosis, suggesting the need to clarify the underlying pathophysiology. Among the micronutrients (trace elements) that are essential to humans, inadequate iron status has previously been implicated in the pathogenesis of CRAS; however, the roles of other trace elements remain unclear. Selenium critically regulates the function of selenoproteins, in which selenocysteine is present at the active centres. The human genome encodes 25 selenoproteins, and accumulating data indicate that they regulate diverse physiological processes, including cellular redox homeostasis, calcium flux, thyroid hormone activity and haematopoiesis, all of which directly or indirectly influence cardiac function. The essential role of selenium in human health is underscored by the fact that its deficiency results in multiple disorders, among which are cardiomyopathy and abnormal erythrocyte morphology. Studies have shown that selenium deficiency is not uncommon in CKD patients with poor nutritional status, suggesting that it may be an under-recognized cause of anaemia and cardiovascular disorders in these patients. In this review, we discuss the role of selenium in the pathophysiology of CKD, particularly in the context of the interconnection among CKD, cardiac dysfunction and anaemia. Given that selenium deficiency is associated with treatment-resistant anaemia and an increased risk of CVD, its role as a key modulator of CRAS merits future investigation.

A comprehensive review on selenium and blood pressure: Recent advances and research perspectives

BACKGROUND

Globally, approximately 31.1 % of adults are affected by hypertension(HTN), and there is currently no effective treatment for this condition. Selenium (Se), an essential trace element in the human body, has been shown to play a role in various biological processes, including anti-inflammation, antioxidative stress, anti-ferroptosis, and regulation of immune response. Research suggests that Se may have potential hypotensive effects.

OBJECTIVE

This review aims to comprehensively investigate the relationship between Se and blood pressure(BP), elucidate the mechanisms through which Se influences BP, and explore its prospective applications in clinical practice.

METHODS

We conducted a systematic search on PubMed for a thorough review of articles concerning the relationship between Se and BP, as well as the mechanisms by which Se may lower BP.

RESULTS AND CONCLUSIONS

Although some findings indicate that Se might increase BP, its anti-inflammatory, anti-oxidant, anti-vascular remodeling, anti-atherosclerotic, anti-ferroptosis, and regulation of immune response effects suggest that maintaining an appropriate level of Se may contribute to BP reduction and possibly lower the risk of pregnancy-induced hypertension(PIH). While Se shows promise in the management of HTN, further exploration is necessary for its development. Future studies should clarify the mechanisms involved and identify relevant targets through clinical research, which may provide adjunctive therapies for HTN.

Recent research progress on the biological functions, synthesis and applications of selenium nanoparticles

Selenium is an essential trace element that is involved in a variety of complex biological processes and has a significant positive effect on the prevention and treatment of cardiovascular disease, inflammatory diseases, and cancer. Selenium in the body is mainly provided by daily meals. However, selenium has two sides, beneficial in moderation and harmful in excess. Selenium nanoparticles (SeNPs), which has better biocompatibility, safety and stability compared with other forms of selenium, is a good choice for selenium supplementing. Current researchers are exploring SeNPs in a variety of ways, including but not limited to antioxidant, antimicrobial, antiviral, inhibition of inflammation, anti-tumor, development of bio-diagnostic reagents, and nano-carrier systems. Also, efforts are being made to synthesize stable and efficient SeNPs for various applications. This study briefly describes how SeNPs are synthesized, summarizes in detail the wide range of uses of SeNPs, and provides an outlook on the future development of it. In addition, combined with the research results of our group, this study discusses the application and biological assays of SeNPs in diagnosis, which will provide inspiration and help for researchers to broaden the application of SeNPs.

Selenocysteine-Activatable Near-Infrared Fluorescent Probe for Screening of Anti-inflammatory Components in Herbs

Inflammation, a central process in numerous diseases, plays a crucial role in hepatic disorders, arthritis, cardiac conditions, and neurodegenerative ailments. Given the lack of effective anti-inflammatory drugs, it is imperative to assess inflammation severity and explore novel therapeutics. Selenocysteine (Sec), a key mediator of selenium's biological function, is closely involved in anti-inflammatory responses. We have synthesized a novel near-infrared fluorescent probe, Sec-BDP, which can image Sec dynamics in vivo with high selectivity and sensitivity. Sec-BDP detects Sec at concentrations as low as 0.085 μM. Utilizing this probe, we visualized Sec levels in cell, zebrafish, and mouse inflammation models, enabling a clear assessment of inflammation severity. To screen for drug candidates, Sec-BDP was integrated with ultrahigh performance liquid chromatography quadrupole time-of-flight mass spectrometry to identify potent anti-inflammatory compounds in Astragalus membranaceus, such as 5-O-methylvisammioside. Imaging of Sec with Sec-BDP provides insights into Sec-related diseases and aids in discovering new treatments. This probe advances selenium biology and promises more targeted therapeutic strategies.

Cadmium and selenium blood levels in association with congestive heart failure in diabetic and prediabetic patients: a cross-sectional study from the national health and nutrition examination survey

BACKGROUND

Epidemiological research on the association between heavy metals and congestive heart failure (CHF) in individuals with abnormal glucose metabolism is scarce. The study addresses this research gap by examining the link between exposure to heavy metals and the odds of CHF in a population with dysregulated glucose metabolism.

METHOD

This cross-sectional study includes 7326 patients with diabetes and prediabetes from the National Health and Nutrition Examination Survey from 2011 to 2018. The exposure variables are five environmental heavy metals-cadmium (Cd), lead (Pb), mercury (Hg), selenium (Se), and manganese (Mn)-and the endpoint is CHF, determined via face-to-face interviews. Logistic regression, weighted quantile sum (WQS), and Bayesian kernel machine learning (BKMR) models were employed to investigate the association between exposure to mixtures of five heavy metals and the odds of having CHF in individuals with diabetes and prediabetes.

RESULT

Multivariate logistic regression analysis Shows that only blood Cd exhibited a significant linear positive correlation with CHF odds (OR: 1.26, 95%CI 1.07-1.47, p = 0.005), there was a significant 14% decrease in the odds rate of CHF for each additional standard deviation of log10 Se (OR: 0.86,95%CI 0.76-0.96, P = 0.009). The WQS index for the metal mixture only marginally increased the odds of CHF by 1% (OR = 1.01, 95% CI 1.00-1.02, P = 0.032). BKMR analysis demonstrated a positive association between Cd levels and the odds of CHF, an inverse relationship with Se levels in patients with diabetes and prediabetes. However, no significant association was observed between the metal mixture and CHF.

CONCLUSION

This cross-sectional study demonstrates that increased Cd levels are associated with a higher odds of CHF in patients with diabetes and pre-diabetes, whereas elevated blood Se levels significantly mitigate this odds.

Micronutrient Deficiencies in Heart Failure and Relationship with Exocrine Pancreatic Insufficiency

BACKGROUND

Micronutrient deficiencies are common and play a significant role in the prognosis of many chronic diseases, including heart failure (HF), but their prevalence in HF is not well known. As studies have traditionally focused on causes originating within the intestines, exocrine pancreatic insufficiency (EPI) has been overlooked as a potential contributor. The exocrine pancreas enables the absorption of various (fat-soluble) micronutrients and may be insufficient in HF. We hypothesize that EPI contributes to micronutrient deficiencies in HF.

OBJECTIVES

To evaluate micronutrient concentrations in HF cases and their association with clinical characteristics and EPI.

MATERIALS AND METHODS

Plasma samples from 59 consecutive hospitalized patients with HF were analyzed for vitamins A, D, and E and the minerals selenium and zinc. EPI was defined as fecal elastase 1 level < 206 μg/g.

RESULTS

The mean age of patients was 59 ± 14 years, with 24 (41%) being women, and a median NT-proBNP concentration of 3726 [2104-6704] pg/mL was noted. Vitamin A deficiency occurred in eight (14%) of the patients, and 12 (20%) exceeded the upper limit. More than half (51%) were vitamin D-deficient. No patients showed vitamin E deficiency, but 14 (24%) had elevated levels. Selenium deficiency was common, affecting 36 (61%) patients, while zinc was below the normal range in seven patients (12%). Micronutrient levels did not differ significantly based on the presence of EPI.

CONCLUSIONS

This study provides novel insights into the micronutrient status of patients with HF. Deficiencies in vitamins A and D, selenium, and zinc are prevalent in HF, but these findings are not associated with exocrine pancreatic function.

Low Levels of Selenoprotein P Are Associated With Cognitive Impairment in Patients Hospitalized for Heart Failure

BACKGROUND

Selenoprotein P (SELENOP) is a transporter for selenium and has been shown to protect selenium-status maintenance in the brain against deficiency and to support neuronal development, neurogenesis and neurocognitive function. Selenium deficiency has previously been associated with cognitive impairment in various populations, but no studies have been carried out in subjects with heart failure (HF).

PURPOSE

To explore whether SELENOP deficiency in subjects with acute HF is associated with cognitive impairment.

METHODS

Plasma SELENOP, as measured by an immunoassay analysis, is a well-validated marker of plasma selenium status and has the benefit of providing information on the bioavailable fraction of selenium to preferentially supplied cells equipped with receptors for SELENOP uptake. SELENOP was measured in 320 subjects hospitalized for HF. Of the subjects, 187 also underwent 4 cognitive tests assessing global cognitive function: Montreal Cognitive Assessment (MoCA); information processing (Symbol Digit Modalities Test [SDMT]); visual attention and task switching (Trailmaking Test A [TMT-A]); and executive speed (A Quick Test of Cognitive Speed [AQT] form and color). Appropriate cutoffs were used for each cognitive test to define cognitive impairment. Cross-sectional associations between SELENOP concentrations and cognitive impairment, as defined by each cognitive test, were explored using multivariable logistic models. Further, multivariable logistic models exploring associations between selenium deficiency, defined as the lowest quartile of SELENOP levels, and cognitive impairment, defined by each cognitive test, were carried out.

RESULTS

The 187 participants had a mean age of 73 (± 11.9) years; 31% were female and had a mean body mass index of 28.1 (± 5.6) kg/m2. Each 1 standard deviation increment in SELENOP concentrations was associated with lower odds of cognitive impairment, defined as a MoCA cut-off score < 23 (odds ratio [OR] 0.60; 95% CI 0.40-0.91; P = 0.017). Further, SELENOP concentrations in the lowest quartile (≤ 2.3 mg/L) were associated with cognitive impairment as measured by MoCA (OR 3.10; 95% CI 1.38-6.97; P = 0.006), SDMT (OR 2.26; 95% CI 1.10-4.67; P = 0.027) and TMT-A (OR 3.40; 95% CI 1.47-7.88; P = 0.004) but not by AQT form and color.

CONCLUSIONS

In subjects admitted for HF, higher SELENOP concentrations were associated with better performance on the MoCA test, reflecting global cognition, and SELENOP deficiency was associated with cognitive impairment as defined by 3 cognitive tests.

The enhancing effects of selenomethionine on harmine in attenuating pathological cardiac hypertrophy via glycolysis metabolism

Pathological cardiac hypertrophy, a common feature in various cardiovascular diseases, can be more effectively managed through combination therapies using natural compounds. Harmine, a β-carboline alkaloid found in plants, possesses numerous pharmacological functions, including alleviating cardiac hypertrophy. Similarly, Selenomethionine (SE), a primary organic selenium source, has been shown to mitigate cardiac autophagy and alleviate injury. To explores the therapeutic potential of combining Harmine with SE to treat cardiac hypertrophy. The synergistic effects of SE and harmine against cardiac hypertrophy were assessed in vitro with angiotensin II (AngII)-induced hypertrophy and in vivo using a Myh6R404Q mouse model. Co-administration of SE and harmine significantly reduced hypertrophy-related markers, outperforming monotherapies. Transcriptomic and metabolic profiling revealed substantial alterations in key metabolic and signalling pathways, particularly those involved in energy metabolism. Notably, the combination therapy led to a marked reduction in the activity of key glycolytic enzymes. Importantly, the addition of the glycolysis inhibitor 2-deoxy-D-glucose (2-DG) did not further potentiate these effects, suggesting that the antihypertrophic action is predominantly mediated through glycolytic inhibition. These findings highlight the potential of SE and harmine as a promising combination therapy for the treatment of cardiac hypertrophy.

High selenium diet attenuates pressure overload-induced cardiopulmonary oxidative stress, inflammation, and heart failure

Selenium (Se) deficiency is associated with the development of Keshan disease, a cardiomyopathy associated with massive cardiac immune cell infiltration that can lead to heart failure (HF). The purpose of this study was to determine whether high Se diet can attenuate systolic overload-induced cardiopulmonary inflammation and HF. Briefly, transverse aortic constriction (TAC)-induced cardiopulmonary oxidative stress, inflammation, left ventricular (LV) dysfunction, and pulmonary remodeling were determined in male mice fed with either high Se diet or normal Se diet. High Se diet had no detectable effect on LV structure and function in mice under control conditions, but high Se diet significantly protected mice from TAC-induced LV hypertrophy, dysfunction, increase of lung weight, and right ventricular hypertrophy. As compared with mice treated with normal Se diet, high Se diet also reduced TAC-induced LV cardiomyocyte hypertrophy, fibrosis, leukocyte infiltration, pulmonary inflammation, pulmonary fibrosis, and pulmonary micro-vessel muscularization. In addition, high Se diet significantly ameliorated TAC-induced accumulation and activation of pulmonary F4/80+ macrophages, and activation of dendritic cells. Interestingly, high Se diet also significantly attenuated TAC-induced activation of pulmonary CD4+ and CD8+ T cells. Moreover, we found that TAC caused a significant increase in cardiac and pulmonary ROS production, increases of 4-hydroxynonenal (4-HNE) and 3-nitrotyrosine (3-NT), as well as a compensatory increases of LV glutathione peroxidase 1 (GPX1) and 4 (GPX4) in mice fed with normal Se diet. Above changes were diminished in mice fed with high Se diet. Collectively, these data demonstrated that high Se diet significantly attenuated systolic pressure overload-induced cardiac oxidative stress, inflammation, HF development, and consequent pulmonary inflammation and remodeling.

Beyond the Gut: Exploring Cardiovascular Implications of Celiac Disease

Celiac disease (CD) is an autoimmune disorder that presents with gastrointestinal symptoms including diarrhea, weight loss, and abdominal bloating due to the inflammation in the small intestine. It has been associated with various extraintestinal manifestations, including mucocutaneous findings such as dermatitis herpetiformis, anemia, dental enamel defects, osteoporosis, and arthritis. Studies have revealed an increasing association between CD and cardiovascular diseases (CVDs), including atherosclerosis, cardiomyopathy, and arrhythmia. Chronic inflammation, nutritional deficiencies from malabsorption, endothelial dysfunction, thrombophilic autoantibodies, thrombocytosis, and protein C and S deficiency have been proposed as the probable mechanisms for the association between the 2 conditions. This article aims to provide a review of the pathophysiological mechanism of celiac disease causing various CVDs and to compare and contrast the existing studies suggesting both favorable and unfavorable CVD outcomes in patients with CD.

An Examination of Chemical Tools for Hydrogen Selenide Donation and Detection

Hydrogen selenide (H2Se) is an emerging biomolecule of interest with similar properties to that of other gaseous signaling molecules (i.e., gasotransmitters that include nitric oxide, carbon monoxide, and hydrogen sulfide). H2Se is enzymatically generated in humans where it serves as a key metabolic intermediate in the production of selenoproteins and other selenium-containing biomolecules. However, beyond its participation in biosynthetic pathways, its involvement in cellular signaling or other biological mechanisms remains unclear. To uncover its true biological significance, H2Se-specific chemical tools capable of functioning under physiological conditions are required but lacking in comparison to those that exist for other gasotransmitters. Recently, researchers have begun to fill this unmet need by developing new H2Se-releasing compounds, along with pioneering methods for selenide detection and quantification. In combination, the chemical tools highlighted in this review have the potential to spark groundbreaking explorations into the chemical biology of H2Se, which may lead to its branding as the fourth official gasotransmitter.

Association of Blood Selenium Levels with Diabetes and Heart Failure in American General Adults: a Cross-sectional Study of NHANES 2011-2020 pre

Selenium is an essential trace element closely related to human health; however, the relationship between blood selenium levels, diabetes, and heart failure remains inconclusive. Therefore, this study aimed to explore the relationship between blood selenium levels and the prevalence of diabetes as well as heart failure in American general adults aged 20 years or older. This study utilized data from four survey cycles from NHANES 2011-2020 pre. Blood selenium levels were considered as both a continuous variable and quartiles, and logistic regression was employed to investigate the associations between blood selenium levels with diabetes and heart failure. Nonlinear relationships were examined by restricted cubic spline regression. The analysis included a total of 16311 participants aged 20 years or older. After adjustment for all potential confounder, we found when the blood selenium levels increased by 10 ug/L, the average risk of diabetes increased by 4.2% (95% CI: 1.5%, 7.0%), and the average risk of heart failure decreased by 5.0% (95% CI: 0.1%, 9.8%). In addition, compared with the lowest reference group, blood selenium levels were significantly positively associated with risk of diabetes in participants in the fourth quartile (OR=1.458, 95% CI: 1.173, 1.812), while significantly negatively associated with the risk of heart failure in participants in the second, third and fourth quartiles (Q2, OR=0.677, 95% CI: 0.471, 0.974) (Q3, OR=0.609, 95% CI: 0.426, 0.870) (Q4, OR=0.653, 95% CI: 0.443, 0.961). There was a nonlinear and reverse L-shaped association between blood selenium and diabetes, while a negative dose-response association between blood selenium and heart failure. Furthermore, the association between blood selenium levels and heart failure was more pronounced in participants with poor glycemic control, rather than diabetic patients. High blood selenium levels may be positively related to diabetes, while low blood selenium levels may be associated to heart failure. Appropriate blood selenium levels may help prevent diabetes and heart failure.

Interaction effect between blood selenium levels and stroke history on all-cause mortality: a retrospective cohort study of NHANES

Aim

The study aimed to investigate the interaction effect between blood selenium levels and stroke history on all-cause mortality.

Methods

In this retrospective cohort study, participant data were obtained from the National Health and Nutrition Examination Survey (NHANES) 2011-2018. The covariates were screened via the backward selection method in weighted univariate and multivariate Cox regression models. Weighted univariate and multivariate Cox regression models were conducted to investigate the association of blood selenium and stroke history with all-cause mortality. The results were expressed as hazard ratios (HRs) and 95% confidence intervals (CIs). The synergy index (SI) was used to assess the assistive interaction. The association was further explored in different gender groups.

Results

Totally, 8,989 participants were included, of whom 861 (9.57%) died. Participants with blood selenium ≥192.96 ug/L were associated with lower odds of all-cause mortality (HR = 0.70, 95% CI: 0.58-0.84), whereas those with a stroke history were associated with a higher risk of all-cause mortality (HR = 1.57, 95% CI: 1.15-2.16). Compared to participants with blood selenium ≥192.96 ug/L and non-stroke history, participants with both blood selenium < 192.96 ug/L and stroke history had a higher all-cause mortality risk (HR = 2.31, 95% CI: 1.62-3.29; SI = 0.713, 95% CI: 0.533-0.952). All participants with blood selenium < 192.96 ug/L and stroke history were related to higher all-cause mortality risk (HR = 1.61, 95% CI: 1.21-2.13). In males, the interaction effect of blood selenium and stroke history on all-cause mortality (HR = 2.27, 95% CI: 1.50-3.46; SI = 0.651, 95% CI: 0.430-0.986) increased twice.

Conclusion

Blood selenium and stroke history have an interaction effect on all-cause mortality. Increasing selenium-rich food or supplement intake, especially for individuals with a stroke history, may improve poor prognosis.

Risk of heavy metal(loid) compositions in fine particulate matter on acute cardiovascular mortality: a poisson analysis in Anyang, China

Fine particulate matter (PM2.5) is a risk factor of cardiovascular disease. Associations between PM2.5 compositions and cardiovascular disease are a point of special interest but inconsistent. This study aimed to explore the cardiovascular effects of heavy metal(loid) compositions in PM2.5. Data for mortality, air pollutants and meteorological factors in Anyang, China from 2017 to 2021 were collected. Heavy metal(loid) in PM2.5 were monitored and examined monthly. A Case-crossover design was applied to the estimated data set. The interquartile range increase in cadmium (Cd), antimony (Sb) and arsenic (As) at lag 1 was associated with increment of 8.1% (95% CI: 3.3, 13.2), 4.8% (95% CI: 0.2, 9.5) and 3.5% (95% CI: 1.1, 6.0) cardiovascular mortality. Selenium in lag 2 was inversely associated with cerebrovascular mortality (RR = 0.920 95% CI: 0.862, 0.983). Current-day exposure of aluminum was positively associated with mortality from ischemic heart disease (RR = 1.083 95% CI: 1.001, 1.172). Stratified analysis indicated sex, age and season modified the cardiovascular effects of As (P < 0.05). Our study reveals that heavy metal(loid) play key roles in adverse effects of PM2.5. Cd, Sb and As were significant risk factors of cardiovascular mortality. These findings have potential implications for accurate air pollutants control and management to improve public health benefits.

An untargeted metabolomics study of cardiac pathology damage in rats caused by low selenium diet alone or in combination with T-2 toxin

T-2 toxin is a highly cardiotoxic environmental contaminant. Selenium can uphold the cardiovascular system's functionality. Selenium insufficiency is common. The aim of this study was to elucidate the effects of low selenium diet alone or in combination with T-2 toxin on myocardial tissue damage. Thirty-two Sprague-Dawley rats of 3 weeks of age were randomized into control, low selenium diet, low selenium diet combined with T-2 toxin groups (at doses of 10 ng/g and 100 ng/g body weight) for 12-weeks intervention. Pathohistology and ultrastructural changes in cardiac tissue were observed. Changes in cardiac metabolites were analyzed using untargeted metabolomics. The findings demonstrated that cardiac tissue abnormalities, interstitial bleeding, inflammatory cell infiltration, and mitochondrial damage can be brought on by low selenium diet alone or in combination with the T-2 toxin. A low selenium diet alone or in combination with the T-2 toxin affected cardiac metabolic profiles and resulted in aberrant modifications in many metabolic pathways, including the metabolism of amino acids, cholesterol, and thiamine. Accordingly, low selenium diet and T-2 toxin may have a synergistic effect. Our findings provide fresh insights into the processes of cardiac injury by revealing the effects of low selenium diet and T-2 toxin on cardiac metabolism.

Comprehensive analysis of environmental exposure to hazardous trace elements and lung function: a national cross-sectional study

BACKGROUND

There is growing interest in the joint effects of hazardous trace elements (HTEs) on lung function deficits, but the data are limited. This is a critical research gap given increased global industrialisation.

METHODS

A national cross-sectional study including spirometry was performed among 2112 adults across 11 provinces in China between 2020 and 2021. A total of 27 HTEs were quantified from urine samples. Generalised linear models and quantile-based g-computation were used to explore the individual and joint effects of urinary HTEs on lung function, respectively.

RESULTS

Overall, there were negative associations between forced expiratory volume in 1 s (FEV1) and urinary arsenic (As) (z-score coefficient, -0.150; 95% CI, -0.262 to -0.038 per 1 ln-unit increase), barium (Ba) (-0.148, 95% CI: -0.258 to -0.039), cadmium (Cd) (-0.132, 95% CI: -0.236 to -0.028), thallium (Tl) (-0.137, 95% CI: -0.257 to -0.018), strontium (Sr) (-0.147, 95% CI: -0.273 to -0.022) and lead (Pb) (-0.121, 95% CI: -0.219 to -0.023). Similar results were observed for forced vital capacity (FVC) with urinary As, Ba and Pb and FEV1/FVC with titanium (Ti), As, Sr, Cd, Tl and Pb. We found borderline associations between the ln-quartile of joint HTEs and decreased FEV1 (-20 mL, 95% CI: -48 to +8) and FVC (-14 mL, 95% CI: -49 to+2). Ba and Ti were assigned the largest negative weights for FEV1 and FVC within the model, respectively.

CONCLUSION

Our study investigating a wide range of HTEs in a highly polluted setting suggests that higher urinary HTE concentrations are associated with lower lung function, especially for emerging Ti and Ba, which need to be monitored or regulated to improve lung health.

Association between dietary inflammatory index and NT-proBNP levels in US adults: A cross-sectional analysis

BACKGROUND

With cardiovascular diseases standing as a leading cause of mortality worldwide, the interplay between diet-induced inflammation, as quantified by the Dietary Inflammatory Index (DII), and heart failure biomarker NT-proBNP has not been investigated in the general population.

METHODS

This study analyzed data from the National Health and Nutrition Examination Survey (NHANES) 1999-2004, encompassing 10,766 individuals. The relationship between the DII and NT-proBNP levels was evaluated through multivariable-adjusted regression models. To pinpoint crucial dietary components influencing NT-proBNP levels, the LASSO regression model was utilized. Stratified analyses were then conducted to examine the associations within specific subgroups to identify differential effects of the DII on NT-proBNP levels across diverse populations.

RESULTS

In individuals without heart failure, a unit increase in the DII was significantly associated with an increase in NT-proBNP levels. Specifically, NT-proBNP levels rose by 9.69 pg/mL (95% CI: 6.47, 12.91; p < 0.001) without adjustments, 8.57 pg/mL (95% CI: 4.97, 12.17; p < 0.001) after adjusting for demographic factors, and 5.54 pg/mL (95% CI: 1.75, 9.32; p = 0.001) with further adjustments for health variables. In participants with a history of heart failure, those in the second and third DII quartile showed a trend towards higher NT-proBNP levels compared to those in the lowest quartile, with increases of 717.06 pg/mL (95% CI: 76.49-1357.63, p = 0.030) and 855.49 pg/mL (95% CI: 156.57-1554.41, p = 0.018). Significant interactions were observed in subgroup analyses by age (<50: β = 3.63, p = 0.141; 50-75: β = 18.4, p<0.001; >75: β = 56.09, p<0.001), gender (men: β = 17.82, p<0.001; women: β = 7.43, p = 0.061),hypertension (β = 25.73, p<0.001) and diabetes (β = 38.94, p<0.001).

CONCLUSION

This study identified a positive correlation between the DII and NT-proBNP levels, suggesting a robust link between pro-inflammatory diets and increased heart failure biomarkers, with implications for dietary modifications in cardiovascular risk management.

Selenium as a Modulator of Redox Reactions in the Prevention and Treatment of Cardiovascular Diseases

Cardiovascular diseases stand as the predominant global cause of mortality, exerting a profound impact on both life expectancy and its quality. Given their immense public health burden, extensive efforts have been dedicated to comprehending the underlying mechanisms and developing strategies for prevention and treatment. Selenium, a crucial participant in redox reactions, emerges as a notable factor in maintaining myocardial cell homeostasis and influencing the progression of cardiovascular disorders. Some disorders, such as Keshan disease, are directly linked with its environmental deficiency. Nevertheless, the precise extent of its impact on the cardiovascular system remains unclear, marked by contradictory findings in the existing literature. High selenium levels have been associated with an increased risk of developing hypertension, while lower concentrations have been linked to heart failure and atrial fibrillation. Although some trials have shown its potential effectiveness in specific groups of patients, large cohort supplementation attempts have generally yielded unsatisfactory outcomes. Consequently, there persists a significant need for further research aimed at delineating specific patient cohorts and groups of diseases that would benefit from selenium supplementation.

Varying association of nutrient intakes with quality of life in patients receiving different modes of dialysis

Background

Nutrients are crucial for dialysis patients, especially elderly patients. Nutrition-related complications in dialysis patients are often closely related to cardiovascular aging. However, we know little about the effect of different nutrients on the commonly used outcome predictor, health-related quality of life (HRQOL). Therefore, this study investigated the associations between different nutrients and HRQOL among dialysis patients.

Methods

A cross-sectional study was conducted on 123 dialysis adults at multiple dialysis centers. The Short Form-36 Health Survey (SF-36) assesses HRQOL. Modified quantitative subjective global assessment (MQSGA) evaluates nutritional status. A 3-day dietary record evaluated nutrient intakes.

Results

Among the 123 participants, 79 received hemodialysis (HD), and 44 were on peritoneal dialysis (PD). Patients with PD had a higher SF-36 score than HD (525 ± 136 vs. 375 ± 179, P < 0.001). A negative association between nutrition status and HRQOL was observed in HD (regression coefficient β = -17.4, P < 0.001) but not in PD (β = -12.3, P = 0.07). For HD patients, the nutrition status was negatively correlated with intakes of carbohydrates, fiber, selenium, copper, and Manganese (β = -0.02, P = 0.032; β = -0.3, P = 0.031; β = -0.1, P = 0.006; β = -2.3, P = 0.025; β = -1.3, P = 0.003, respectively). Their HRQOL was positively associated with calories, fat, niacin, and vitamin E (β = 2.19, P = 0.035; β = 2.4, P = 0.043; β = 8.5, P = 0.044; β = 6.9, P = 0.017, respectively). Conversely, for patients with PD, only vitamin B2 was found to be adversely correlated with their nutritional status (β = -5.2, P = 0.037), and increased intakes of vitamin A, vitamin C and fiber (β = 0.1, P = 0.031; β = 0.8, P = 0.028; β = 15.8, P = 0.045, respectively) were associated with a better HRQOL.

Conclusions

The nutritional intake of PD patients and HD patients affects their quality of life differently. Macronutrients significantly impact HRQOL in HD patients, while vitamins have a more substantial impact on PD patients.

Association between low selenoprotein P concentrations and anaemia in hospitalized heart failure patients

AIMS

Heart failure (HF) patients with anaemia tend to have a worse outcome, with increased hospitalization rates, decreased exercise tolerance, and higher mortality compared to those without anaemia. Limited research exists on the association between selenium deficiency and anaemia specifically in HF patients, despite previous findings of a correlation in different populations. The BIOSTAT-CHF study demonstrated that higher selenium levels in HF patients were associated to a lower risk of anaemia and iron deficiency. This study investigates the relationship between selenoprotein P (SELENOP) concentrations, a major contributor and functional biomarker of selenium transport, and anaemia, Hb levels, and iron status in hospitalized HF patients.

METHODS AND RESULTS

SELENOP was analysed in 320 hospitalized HF subjects, with complete data available for 310 subjects. The relationships between continuous SELENOP concentrations and 1) Hb concentrations, 2) anaemia (Hb < 115 g/L (women), <130 g/L (men)), and 3) iron status (as measured by transferrin receptor 1 (TfR1) which increases in iron deficiency) were evaluated using multivariable logistic and linear regression models. Additionally, SELENOP concentrations in the lowest quartile were related to anaemia, haemoglobin, and iron state in multivariable logistic and linear models. The mean age of the study population was 75.0 ± 11.6 years, and 30% were women. Anaemia was present in 133 subjects (42.9%). SELENOP concentrations were positively correlated with haemoglobin concentrations (0.238; P < 0.001) and negatively with TfR1 concentrations (-0.238, P < 0.001). In multivariable regression models, higher SELENOP concentrations were associated with higher Hb concentrations (B = 3.23; P = 0.002) and lower TfR1 concentrations (B = -0.20; P < 0.001). Furthermore, SELENOP deficiency was associated with lower Hb concentrations (B = -7.64: P = 0.001), higher TfR1 concentrations (B = 0.31; P = 0.003), and higher odds of anaemia in HF patients (odds ratio 2.17; 95% confidence interval 1.23-3.82; P = 0.008).

CONCLUSIONS

In hospitalized heart failure patients, lower concentrations of SELENOP were associated with higher prevalence of anaemia.

Preoperative serum selenium predicts acute kidney injury after adult cardiac surgery

BACKGROUND

The relationship between serum selenium (Se) and acute kidney injury after adult cardiac surgery (CSA-AKI) remains controversial. This study aimed to investigate the association of preoperative Se level with incident CSA-AKI.

METHOD AND RESULTS

A retrospective cohort study was conducted on patients who underwent cardiac surgery. The primary outcome was incident CSA-AKI. Multivariable logistic regression models and natural cubic splines were used to estimate the association of Se levels and primary outcome. A total of 453 patient with a mean age of 62.97 years were included. Among all patients, 159 (35.1%) incident cases of CSA-AKI were identified. The level of preoperative Se concentration in patients with CSA-AKI was significant lower than that in patients without CSA-AKI. The higher preoperative Se level was significantly associated with decreased risk of CSA-AKI (adjusted OR 0.91, 95% CI: 0.87-0.99). Dose-response relationship curve revealed a nearly L-shape correlation between serum Se selenium levels and incident CSA-AKI.

CONCLUSION

Our study suggested that a higher level of serum Se was significantly associated with lower risk of CSA-AKI. Further prospective studies are needed to clarify the causal relationship between serum Se level and incident CSA-AKI.

Expanding the Frontiers of Guardian Antioxidant Selenoproteins in Cardiovascular Pathophysiology

Significance: Physiological levels of reactive oxygen and nitrogen species (ROS/RNS) function as fundamental messengers for many cellular and developmental processes in the cardiovascular system. ROS/RNS involved in cardiac redox-signaling originate from diverse sources, and their levels are tightly controlled by key endogenous antioxidant systems that counteract their accumulation. However, dysregulated redox-stress resulting from inefficient removal of ROS/RNS leads to inflammation, mitochondrial dysfunction, and cell death, contributing to the development and progression of cardiovascular disease (CVD). Recent Advances: Basic and clinical studies demonstrate the critical role of selenium (Se) and selenoproteins (unique proteins that incorporate Se into their active site in the form of the 21st proteinogenic amino acid selenocysteine [Sec]), including glutathione peroxidase and thioredoxin reductase, in cardiovascular redox homeostasis, representing a first-line enzymatic antioxidant defense of the heart. Increasing attention has been paid to emerging selenoproteins in the endoplasmic reticulum (ER) (i.e., a multifunctional intracellular organelle whose disruption triggers cardiac inflammation and oxidative stress, leading to multiple CVD), which are crucially involved in redox balance, antioxidant activity, and calcium and ER homeostasis. Critical Issues: This review focuses on endogenous antioxidant strategies with therapeutic potential, particularly selenoproteins, which are very promising but deserve more detailed and clinical studies. Future Directions: The importance of selective selenoproteins in embryonic development and the consequences of their mutations and inborn errors highlight the need to improve knowledge of their biological function in myocardial redox signaling. This could facilitate the development of personalized approaches for the diagnosis, prevention, and treatment of CVD. Antioxid. Redox Signal. 40, 369-432.

The cardiomyopathy of cystic fibrosis: a modern form of Keshan disease

Introduction

We conducted a study to determine the prevalence of structural heart disease in patients with CF, the characteristics of a cardiomyopathy not previously described in this population, and its possible relationship with nutritional deficiencies in CF.

Methods

We studied 3 CMP CF patients referred for heart-lung transplantation and a prospective series of 120 adult CF patients. All patients underwent a clinical examination, blood tests including levels of vitamins and trace elements, and echocardiography with evaluation of myocardial strain. Cardiac magnetic resonance imaging (CMR) was performed in patients with CMP and in a control group. Histopathological study was performed on hearts obtained in transplant or necropsy.

Results

We found a prevalence of 10% (CI 4.6%-15.4%) of left ventricular (LV) dysfunction in the prospective cohort. Myocardial strain parameters were already altered in CF patients with otherwise normal hearts. Histopathological examination of 4 hearts from CF CMP patients showed a unique histological pattern of multifocal myocardial fibrosis similar to Keshan disease. Four of the five CF CMP patients undergoing CMR showed late gadolinium uptake, with a characteristic patchy pattern in 3 cases (p < 0.001 vs. CF controls). Selenium deficiency (Se < 60 µg/L) was associated with more severe LV dysfunction, higher prevalence of CF CMP, higher NTproBNP levels, and more severe pulmonary and digestive involvement.

Conclusion

10% of adults with CF showed significant cardiac involvement, with histological and imaging features resembling Keshan disease. Selenium deficiency was associated with the presence and severity of LV dysfunction in these patients.

Recent Advances on Selenium Nutrition and Keshan Disease

Keshan disease (KD) is a type of endemic cardiomyopathy with an unknown cause. It is primarily found in areas in China with low selenium levels, from northeast to southwest. The nutritional biogeochemical etiology hypothesis suggests that selenium deficiency is a major factor in KD development. Selenium is important in removing free radicals and protecting cells and tissues from peroxide-induced damage. Thus, low environmental selenium may affect the selenium level within the human body, and selenium level differences are commonly observed between healthy people in KD and nonKD areas. From the 1970s to the 1990s, China successfully reduced KD incidence in endemic KD areas through a selenium supplementation program. After years of implementing prevention and control measures, the selenium level of the population in the KD areas has gradually increased, and the prevalence of KD in China has remained low and stable in recent years. Currently, the pathogenesis of KD remains vague, and the effect of selenium supplementation on the prognosis of KD still needs further study. This paper comprehensively reviews selenium deficiency and its connection to KD. Thus, this study aims to offer novel ideas and directions to effectively prevent and treat KD in light of the current situation.

Contaminant Metals and Cardiovascular Health

A growing body of research has begun to link exposure to environmental contaminants, such as heavy metals, with a variety of negative health outcomes. In this paper, we sought to review the current research describing the impact of certain common contaminant metals on cardiovascular (CV) health. We reviewed ten metals: lead, barium, nickel, chromium, cadmium, arsenic, mercury, selenium, zinc, and copper. After a literature review, we briefly summarized the routes of environmental exposure, pathophysiological mechanisms, CV health impacts, and exposure prevention and/or mitigation strategies for each metal. The resulting article discloses a broad spectrum of pathological significance, from relatively benign substances with little to no described effects on CV health, such as chromium and selenium, to substances with a wide-ranging and relatively severe spectrum of CV pathologies, such as arsenic, cadmium, and lead. It is our hope that this article will provide clinicians with a practical overview of the impact of these common environmental contaminants on CV health as well as highlight areas that require further investigation to better understand how these metals impact the incidence and progression of CV diseases.

Four-week administration of an energy and protein dense oral nutritional supplement improves micronutrient concentrations but does not completely correct deficiencies in institutionalized malnourished older adults

Introduction

Poor food intake is common among elderly living in nursing homes, leading to micronutrient deficiency (MD). There are no recommendations for the management of MD in malnourished older adults.

Methods

We conducted a single arm, open-label, multicenter interventional study in institutionalized malnourished older adults to describe the effect of a 4-week daily energy and protein dense oral nutritional supplementation (ONS, 600 kcal, 30 g protein per unit) containing 50% of the recommended daily micronutrient intake on micronutrient status. Plasma concentrations of vitamins (A, B9, B12, C, E), magnesium (Mg), selenium (Se) and zinc (Zn), and erythrocyte vitamin B9 were measured at baseline and after 4 weeks.

Results

Forty-six participants completed the study (age 87.4 ± 6.6). At baseline, the most frequent MD were Se (48%), Zn (35%), Mg (24%) and vitamin C (24%). Plasma concentrations of vitamins B9, B12, C and E, Mg, Se and Zn significantly increased and the proportion of subjects with at least one MD decreased (p = 0.006). However, after 4 weeks, 40% of subjects still had at least one MD.

Discussion

ONS consumption improved micronutrient status but did not correct MD in all participants. Our data suggest that the prescription of vitamin, mineral and trace element supplementation should be considered in institutionalized malnourished older adults in addition to high energy and high protein ONS.

Selenium intake and multiple health-related outcomes: an umbrella review of meta-analyses

Selenium is an essential trace metalloid element that is associated with fundamental importance to human health. Our umbrella review aimed to evaluate the quality of evidence, validity, and biases in the relationship between selenium intake and health-related outcomes according to published systematic reviews with pooled data and meta-analyses. Selenium intake is associated with a decreased risk of digestive system cancers, all-cause mortality, depression, and Keshan disease, when in children reduce the risk of Kashin-Beck disease. Additionally, selenium supplementation can improve sperm quality, polycystic ovary syndrome, autoimmune thyroid disease, cardiovascular disease, and infective outcomes. Selenium supplementation also has relationship with a decreased concentration of serum lipids including total cholesterol and very low-density lipoprotein cholesterol. However, no evidence has shown that selenium is associated with better outcomes among patients in intensive care units. Furthermore, selenium intake may be related with a higher risk of type 2 diabetes and non-melanoma skin cancers. Moreover, most of included studies are evaluated as low quality according to our evidence assessment. Based on our study findings and the limited advantages of selenium intake, it is not recommended to receive extra supplementary selenium for general populations, and selenium supplementation should not be continued in patients whose selenium-deficient status has been corrected.

Selenium in Cancer Rehabilitation-A Retrospective Study from a Specialized Clinic

BACKGROUND

Micronutrient deficiencies are common at the time of cancer diagnosis and are associated with worse prognosis. Little is known about them in cancer rehabilitation.

METHODS

Data from routine health-related quality of life (HRQOL) were analyzed at an inpatient cancer rehabilitation center. Rehabilitation patients completed the EORTC QLQ-C30 questionnaire before and after multidisciplinary rehabilitation treatment and three months after discharge. Selenium and zinc status were measured in whole blood at these three time points. In case of selenium deficiency, up to 600 µg selenium per day as sodium selenite was supplemented for three weeks during and for three months after rehabilitation.

RESULTS

A total of 271 patients (breast, colon, and pancreatic cancer) were included in the analysis. There was clinically meaningful improvement in many domains of the EORTC QLQ-C30 during rehabilitation. However, the effect often waned in the three months after. Prevalence for selenium deficiency varied between 34 to 90% depending on cancer type (breast < colon < pancreas). In contrast, zinc deficiency was rare. Daily selenium supplementation of 600 µg was more efficient to correct selenium deficiency compared to 300 µg selenium per day. Rehabilitation and increasing selenium status after rehabilitation were associated with improved global quality of life, physical and emotional functioning, and fatigue. In cancer patients with decreasing selenium status, values of global quality of life, physical and emotional functioning, and fatigue were back to the values at the beginning of rehabilitation.

CONCLUSIONS

Selenium deficiency is common in cancer patients admitted to a cancer rehabilitation clinic. Selenium supplementation during rehabilitation effectively corrected selenium deficiency in most cases. The positive effects of rehabilitation persisted longer when selenium status did not decrease after rehabilitation.

Selenium and Selenoproteins in Health

Selenium is a trace mineral that is essential for health. After being obtained from food and taken up by the liver, selenium performs various physiological functions in the body in the form of selenoproteins, which are best known for their redox activity and anti-inflammatory properties. Selenium stimulates the activation of immune cells and is important for the activation of the immune system. Selenium is also essential for the maintenance of brain function. Selenium supplements can regulate lipid metabolism, cell apoptosis, and autophagy, and have displayed significant alleviating effects in most cardiovascular diseases. However, the effect of increased selenium intake on the risk of cancer remains unclear. Elevated serum selenium levels are associated with an increased risk of type 2 diabetes, and this relationship is complex and nonlinear. Selenium supplementation seems beneficial to some extent; however, existing studies have not fully explained the influence of selenium on various diseases. Further, more intervention trials are needed to verify the beneficial or harmful effects of selenium supplementation in various diseases.

Selenium deficiency causes hypertension by increasing renal AT1 receptor expression via GPx1/H2O2/NF-κB pathway

Epidemiological studies show an association between low body selenium and the risk of hypertension. However, whether selenium deficiency causes hypertension remains unknown. Here, we report that Sprague-Dawley rats fed a selenium-deficient diet for 16 weeks developed hypertension, accompanied with decreased sodium excretion. The hypertension of selenium-deficient rats was associated with increased renal angiotensin II type 1 receptor (AT1R) expression and function that was reflected by the increase in sodium excretion after the intrarenal infusion of the AT1R antagonist candesartan. Selenium-deficient rats had increased systemic and renal oxidative stress; treatment with the antioxidant tempol for 4 weeks decreased the elevated blood pressure, increased sodium excretion, and normalized renal AT1R expression. Among the altered selenoproteins in selenium-deficient rats, the decrease in renal glutathione peroxidase 1 (GPx1) expression was most prominent. GPx1, via regulation of NF-κB p65 expression and activity, was involved in the regulation of renal AT1R expression because treatment with dithiocarbamate (PDTC), an NF-κB inhibitor, reversed the up-regulation of AT1R expression in selenium-deficient renal proximal tubule (RPT) cells. The up-regulation of AT1R expression with GPx1 silencing was restored by PDTC. Moreover, treatment with ebselen, a GPX1 mimic, reduced the increased renal AT1R expression, Na+-K+-ATPase activity, hydrogen peroxide (H2O2) generation, and the nuclear translocation of NF-κB p65 protein in selenium-deficient RPT cells. Our results demonstrated that long-term selenium deficiency causes hypertension, which is due, at least in part, to decreased urine sodium excretion. Selenium deficiency increases H2O2 production by reducing GPx1 expression, which enhances NF-κB activity, increases renal AT1R expression, causes sodium retention and consequently increases blood pressure.

A Pilot Study on Oxidative Stress during the Recovery Phase in Critical COVID-19 Patients in a Rehabilitation Facility: Potential Utility of the PAOT® Technology for Assessing Total Anti-Oxidative Capacity

BACKGROUND

Oxidative stress (OS) could cause various COVID-19 complications. Recently, we have developed the Pouvoir AntiOxydant Total (PAOT®) technology for reflecting the total antioxidant capacity (TAC) of biological samples. We aimed to investigate systemic oxidative stress status (OSS) and to evaluate the utility of PAOT® for assessing TAC during the recovery phase in critical COVID-19 patients in a rehabilitation facility.

MATERIALS AND METHODS

In a total of 12 critical COVID-19 patients in rehabilitation, 19 plasma OSS biomarkers were measured: antioxidants, TAC, trace elements, oxidative damage to lipids, and inflammatory biomarkers. TAC level was measured in plasma, saliva, skin, and urine, using PAOT and expressed as PAOT-Plasma, -Saliva, -Skin, and -Urine scores, respectively. Plasma OSS biomarker levels were compared with levels from previous studies on hospitalized COVID-19 patients and with the reference population. Correlations between four PAOT scores and plasma OSS biomarker levels were analyzed.

RESULTS

During the recovery phase, plasma levels in antioxidants (γ-tocopherol, β-carotene, total glutathione, vitamin C and thiol proteins) were significantly lower than reference intervals, whereas total hydroperoxides and myeloperoxidase (a marker of inflammation) were significantly higher. Copper negatively correlated with total hydroperoxides (r = 0.95, p = 0.001). A similar, deeply modified OSS was already observed in COVID-19 patients hospitalized in an intensive care unit. TAC evaluated in saliva, urine, and skin correlated negatively with copper and with plasma total hydroperoxides. To conclude, the systemic OSS, determined using a large number of biomarkers, was always significantly increased in cured COVID-19 patients during their recovery phase. The less costly evaluation of TAC using an electrochemical method could potentially represent a good alternative to the individual analysis of biomarkers linked to pro-oxidants.

Understanding the Pathogenesis of Cardiac Complications in Patients with Propionic Acidemia and Exploring Therapeutic Alternatives for Those Who Are Not Eligible or Are Waiting for Liver Transplantation

The guidelines for the management of patients affected by propionic acidemia (PA) recommend standard cardiac therapy in the presence of cardiac complications. A recent revision questioned the impact of high doses of coenzyme Q10 on cardiac function in patients with cardiomyopathy (CM). Liver transplantation is a therapeutic option for several patients since it may stabilize or reverse CM. Both the patients waiting for liver transplantation and, even more, the ones not eligible for transplant programs urgently need therapies to improve cardiac function. To this aim, the identification of the pathogenetic mechanisms represents a key point. Aims: This review summarizes: (1) the current knowledge of the pathogenetic mechanisms underlying cardiac complications in PA and (2) the available and potential pharmacological options for the prevention or the treatment of cardiac complications in PA. To select articles, we searched the electronic database PubMed using the Mesh terms "propionic acidemia" OR "propionate" AND "cardiomyopathy" OR "Long QT syndrome". We selected 77 studies, enlightening 12 potential disease-specific or non-disease-specific pathogenetic mechanisms, namely: impaired substrate delivery to TCA cycle and TCA dysfunction, secondary mitochondrial electron transport chain dysfunction and oxidative stress, coenzyme Q10 deficiency, metabolic reprogramming, carnitine deficiency, cardiac excitation-contraction coupling alteration, genetics, epigenetics, microRNAs, micronutrients deficiencies, renin-angiotensin-aldosterone system activation, and increased sympathetic activation. We provide a critical discussion of the related therapeutic options. Current literature supports the involvement of multiple cellular pathways in cardiac complications of PA, indicating the growing complexity of their pathophysiology. Elucidating the mechanisms responsible for such abnormalities is essential to identify therapeutic strategies going beyond the correction of the enzymatic defect rather than engaging the dysregulated mechanisms. Although these approaches are not expected to be resolutive, they may improve the quality of life and slow the disease progression. Available pharmacological options are limited and tested in small cohorts. Indeed, a multicenter approach is mandatory to strengthen the efficacy of therapeutic options.

Use of Microbial Consortia in Bioremediation of Metalloid Polluted Environments

Metalloids are released into the environment due to the erosion of the rocks or anthropogenic activities, causing problems for human health in different world regions. Meanwhile, microorganisms with different mechanisms to tolerate and detoxify metalloid contaminants have an essential role in reducing risks. In this review, we first define metalloids and bioremediation methods and examine the ecology and biodiversity of microorganisms in areas contaminated with these metalloids. Then we studied the genes and proteins involved in the tolerance, transport, uptake, and reduction of these metalloids. Most of these studies focused on a single metalloid and co-contamination of multiple pollutants were poorly discussed in the literature. Furthermore, microbial communication within consortia was rarely explored. Finally, we summarized the microbial relationships between microorganisms in consortia and biofilms to remove one or more contaminants. Therefore, this review article contains valuable information about microbial consortia and their mechanisms in the bioremediation of metalloids.

Selenium Status and Oxidative Stress in SARS-CoV-2 Patients

Background and Objectives: Insufficient intake of essential micronutrient selenium (Se) increases the susceptibility to diseases associated with oxidative stress. The study aim was to assess Se status and oxidative stress in COVID-19 patients depending on severity of the disease. Materials and Methods: Blood plasma of 80 post-COVID-19 disease patients and 40 acutely ill patients were investigated. Concentration of Se was detected by a fluorometric method with di-amino-naphthalene using acidic hydrolysis. Selenoprotein P (Sepp1), malondialdehyde (MDA), and 4-hydroxynonenal (4-HNE) and their metabolite adducts were evaluated by spectrophotometric methods using commercial assay kits. Results: Obtained results demonstrated that Se and Sepp1 concentration in acute patients were significantly (p < 0.05 for Se and p < 0.001 for Sepp1) decreased compared with post-COVID-19 disease patients. However, in post-COVID-19 disease patients, Se values were close to the low limit of the norm for the European population. 4-HNE adducts concentration as a marker of lipid peroxidation was significantly increased in the acute patients group compared to the recovery group (p < 0.001). Conclusions: COVID-19 pathology is characterized by the induction of oxidative stress and suppression of antioxidant defenses during the acute phase. Lower levels of Se and Sepp1 and higher levels of reactive oxygen species reflect this imbalance, highlighting the role of oxidative stress in the disease’s pathogenesis.

IGF-1 boosts mitochondrial function by a Ca2+ uptake-dependent mechanism in cultured human and rat cardiomyocytes

A physiological increase in cardiac workload results in adaptive cardiac remodeling, characterized by increased oxidative metabolism and improvements in cardiac performance. Insulin-like growth factor-1 (IGF-1) has been identified as a critical regulator of physiological cardiac growth, but its precise role in cardiometabolic adaptations to physiological stress remains unresolved. Mitochondrial calcium (Ca²⁺) handling has been proposed to be required for sustaining key mitochondrial dehydrogenase activity and energy production during increased workload conditions, thus ensuring the adaptive cardiac response. We hypothesized that IGF-1 enhances mitochondrial energy production through a Ca²⁺-dependent mechanism to ensure adaptive cardiomyocyte growth. We found that stimulation with IGF-1 resulted in increased mitochondrial Ca²⁺ uptake in neonatal rat ventricular myocytes and human embryonic stem cell-derived cardiomyocytes, estimated by fluorescence microscopy and indirectly by a reduction in the pyruvate dehydrogenase phosphorylation. We showed that IGF-1 modulated the expression of mitochondrial Ca²⁺ uniporter (MCU) complex subunits and increased the mitochondrial membrane potential; consistent with higher MCU-mediated Ca²⁺ transport. Finally, we showed that IGF-1 improved mitochondrial respiration through a mechanism dependent on MCU-mediated Ca²⁺ transport. In conclusion, IGF-1-induced mitochondrial Ca²⁺ uptake is required to boost oxidative metabolism during cardiomyocyte adaptive growth.

Sexual dimorphism in selenium deficiency is associated with metabolic syndrome and prevalence of heart disease

BACKGROUND

Serum selenium levels have been associated with the incidence of heart failure (HF) and signs of the metabolic syndrome. In addition, notable differences have been reported between males and females in food intake and micronutrient metabolism, possibly explaining different health outcomes.

OBJECTIVE

Our objective was to elucidate sex-specific, cross-sectional phenotypic differences in the association of serum selenium concentrations with parameters of metabolic syndrome and HF.

METHODS

We investigated data from individuals from a community-based cohort (PREVEND; N = 4288) and heart failure cohort (BIOSTAT-CHF; N = 1994). In both populations, cross-sectional analyses were performed for potential interaction (p < 0.1) between sex and serum selenium with overlapping signs and clinical parameters of the metabolic syndrome and HF.

RESULTS

Baseline selenium levels of the total cohort were similar between PREVEND (85.7 μg/L) and BIOSTAT-CHF (89.1 μg/L). Females with lower selenium levels had a higher BMI and increased prevalence of diabetes than females with higher selenium, in both PREVEND (p_interaction < 0.001; p_interaction = 0.040, resp.) and BIOSTAT-CHF (p_interaction = 0.021; p_interaction = 0.024, resp.), while opposite associations were observed for males. Additionally, in females, but not in males, lower selenium was associated with a higher prevalence of myocardial infarction (MI) in PREVEND (p_interaction = 0.021) and BIOSTAT-CHF (p_interaction = 0.084).

CONCLUSION

Lower selenium was associated with a higher BMI and increased prevalence of diabetes in females, opposite to males, and was also associated with more MI in females. Interventional studies are needed to validate this observation.

Relationship between selenium status, selenoproteins and COVID-19 and other inflammatory diseases: A critical review

The antioxidant effects of selenium as a component of selenoproteins has been thought to modulate host immunity and viral pathogenesis. Accordingly, the association of low dietary selenium status with inflammatory and immunodeficiency has been reported in the literature; however, the causal role of selenium deficiency in chronic inflammatory diseases and viral infection is still undefined. The COVID-19, characterized by acute respiratory syndrome and caused by the novel coronavirus 2, SARS-CoV-2, has infected millions of individuals worldwide since late 2019. The severity and mortality from COVID-19 have been associated with several factor, including age, sex and selenium deficiency. However, available data on selenium status and COVID-19 are limited, and a possible causative role for selenium deficiency in COVID-19 severity has yet to be fully addressed. In this context, we review the relationship between selenium, selenoproteins, COVID-19, immune and inflammatory responses, viral infection, and aging. Regardless of the role of selenium in immune and inflammatory responses, we emphasize that selenium supplementation should be indicated after a selenium deficiency be detected, particularly, in view of the critical role played by selenoproteins in human health. In addition, the levels of selenium should be monitored after the start of supplementation and discontinued as soon as normal levels are reached. Periodic assessment of selenium levels after supplementation is a critical issue to avoid over production of toxic metabolites of selenide because under normal conditions, selenoproteins attain saturated expression levels that limits their potential deleterious metabolic effects.

Dietary Antioxidant Insufficiency Is Associated With Increased Inflammatory Markers and Poorer Health-Related Quality of Life in Patients With Heart Failure

BACKGROUND

Antioxidant insufficiency, elevated inflammatory markers, and poor health-related quality of life (HRQOL) are prevalent in patients with heart failure (HF).

OBJECTIVE

The objective of this study was to examine the associations among dietary antioxidant intake, inflammatory markers, and HRQOL in patients with HF.

METHODS

This was a secondary analysis of 265 patients with HF who completed a 4-day food diary. We assessed intake of 10 antioxidants: alpha carotene, beta carotene, beta cryptoxanthin, lutein, zeaxanthin, lycopene, vitamins C and E, zinc, and selenium. Antioxidant insufficiency was reflected by a measured level for each antioxidant that was below the estimate average requirement or lower than median for antioxidants without an estimate average requirement. Inflammatory markers including serum C-reactive protein, cytokines (interleukins 6 and 10), tumor necrosis factor-alpha, and soluble receptors (sTNFR1 and sTNFR2) were assessed with enzyme immunoassay. Health-related quality of life was measured using the Minnesota Living with Heart Failure at 12 months.

RESULTS

Dietary antioxidant insufficiency predicted C-reactive protein (β = 0.135, P = .032) and interleukin 10 (β = -.155, P = .027). Patients with higher antioxidant insufficiency had higher C-reactive protein and lower interleukin 10. Both antioxidant insufficiency (β = 0.13, P = .049) and higher C-reactive protein (β = 0.16, P = .019) were independently associated with poorer HRQOL while adjusting for covariates.

CONCLUSIONS

Dietary antioxidant insufficiency was associated with increased markers of inflammation and poorer HRQOL. Improvement of diet quality among patients with HF may be a fruitful area of research for enhancing HRQOL.

Integrative analysis of multiomics data identifies selenium-related gene ALAD associating with keshan disease

Keshan disease is an endemic fatal dilated cardiomyopathy that can cause heart enlargement, heart failure, and cardiogenic death. Selenium deficiency is considered to be the main cause of Keshan disease. However, the molecular mechanism underlying Keshan disease remains unclear. Our whole-exome sequencing from 68 patients with Keshan disease and 100 controls found 199 candidate genes by gene-level burden tests. Interestingly, using multiomics data, the selenium-related gene ALAD (δ-aminolevulinic acid dehydratase) was the only candidate causative gene identified by three different analysis approaches. Based on single-cell transcriptome data, ALAD was highly expressed in cardiomyocytes and double mutations of human ALAD dramatically reduced its enzyme activity in vitro compared to negative control. Functional analysis of ALAD inhibition in mice resulted in a Keshan phenotype with left ventricular enlargement and cardiac dysfunction, whereas administration of sodium selenite markedly reversed the changes caused by ALAD inhibition. In addition, sodium selenite reversed Keshan phenotypes by affecting energy metabolism and mitochondrial function in mice as shown by the transcriptomic and proteomic data and the ultrastructure of cardiac myocytes. Our findings are the first to demonstrate that the selenium-related gene ALAD is essential for cardiac function by maintaining normal mitochondrial activity, providing strong molecular evidence supporting the hypothesis of selenium deficiency in Keshan disease. These results identified ALAD as a novel target for therapeutic intervention in Keshan disease and Keshan disease-related dilated cardiomyopathy.

Selenium Supplementation Protects Against Arsenic-Trioxide-Induced Cardiotoxicity Via Reducing Oxidative Stress and Inflammation Through Increasing NAD+ Pool

Arsenic is an environmental contaminant, and accumulating evidence has indicated that exposure to arsenic can cause various diseases, especially cardiotoxicity. Selenium (Se) exerts a vital role in the regulation of multiple physiological activities. Recently, several studies highlighted that Se treatment can effectively antagonize the toxic effects induced by arsenic. However, the exact underlying effect and mechanism of Se on Arsenic-induced cardiotoxicity has not been explored. In the current study, the arsenic trioxide (ATO)-triggered heart damage mice model was used to explore whether Se exerts protective roles in ATO-related cardiotoxicity and its potential mechanism. Our data showed that Se treatment significantly alleviated ATO-mediated cardiotoxicity evidenced by increased weight, decreased myocardial damage markers, and improved heart functions in mice. Furthermore, we demonstrated that Se remarkably inhibited ATO-mediated oxidative stress and inflammatory responses in heart tissues. Mechanistically, we showed that Se upregulated the levels of NAD⁺ in cardiomyocytes of the mice challenged by ATO, and this effect involved in the activation of the NAD⁺ biosynthesis through the salvage pathway. Collectively, our findings demonstrated that Se protected against ATO-mediated cardiotoxicity by antioxidant and anti-inflammatory effects via increasing the NAD⁺ pool in mice.

Serum Selenium and Incident Cardiovascular Disease in the PREvención con DIeta MEDiterránea (PREDIMED) Trial: Nested Case-Control Study

Background: Selenium is an essential trace mineral with potential interest for cardiovascular disease (CVD) prevention owing to its antioxidant properties. Epidemiological data on selenium status and CVD remain inconsistent. The objective of this study was to ascertain whether low serum selenium (SSe) concentrations are related to an increased risk of a first CVD event in a population at high cardiovascular risk. Methods: We undertook a case-control study nested within the “PREvención con DIeta MEDiterránea” (PREDIMED) trial. A total of 207 participants diagnosed with CVD (myocardial infarction, stroke, or cardiovascular death) during the follow-up period (2003−2010) were matched by sex, age, and intervention group to 436 controls by incidence density sampling. Median time between serum sample collection and subsequent CVD event occurrence was 0.94 years. SSe levels were determined using inductively coupled plasma mass spectrometry analysis. Covariates were assessed through validated questionnaires, in-person interviews, and medical record reviews. Conditional logistic regression was used to calculate multivariable-adjusted odds ratios (ORs). Results: Among women, the mean SSe concentration was lower in cases than in controls (98.5 μg/L vs. 103.8 μg/L; p = 0.016). In controls, SSe levels were directly associated with percentage of total energy intake from proteins and fish intake (p for linear trend < 0.001 and 0.049, respectively), whereas SSe concentrations were inversely associated with age, body mass index, and percentage of total energy intake from carbohydrates (p for linear trend < 0.001, 0.008 and 0.016 respectively). In the total group, we observed an inverse dose−response gradient between SSe levels and risk of CVD in the fully-adjusted model (highest vs. lowest quartile: OR = 0.47, 95% CI: 0.27−0.81; ptrend = 0.003). Conclusions: Among elderly individuals at high cardiovascular risk, high SSe concentrations within population reference values are associated with lower first CVD incidence.

The Relationship Between Plasma Selenium, Antioxidant Status, Inflammatory Responses and Ischemic Cardiomyopathy: A Case-Control Study Based on Matched Propensity Scores

Background

Ischemic cardiomyopathy (ICM) with high morbidity and mortality is closely associated with an abnormal equilibrium of circulation selenium levels. The oxidative stress theory is the most accepted theory of selenium causing ischemic cardiomyopathy. However, the role of inflammatory responses in ICM has received limited attention.

Methods

This study included 119 subjects, 43 of whom were patients with ICM, and 76 were healthy controls. Blood specimens were collected from subjects and serum levels of inflammatory and oxidative stress indicators and plasma levels of selenium were measured.

Results

When plasma selenium and indicators of inflammation and oxidative stress were compared between groups, plasma selenium levels were significantly lower in the ICM group than in the control group (68.83874 vs 104.39775, p=0.02032), while indicators of inflammation such as tumour necrosis factor-alpha (TNF-α) (79.09773 vs 46.15634, p<0.001), interleukin-6 (IL-6) (49.41484 vs 38.46923, p<0.01) and neutrophil/lymphocyte ratio (3.696574 vs 2.383658, p<0.001) were significantly higher in the ICM group than in the control group (all of these results were statistically different). Additionally, malondialdehyde (MDA), a marker of oxidative stress, was considerably higher in the ICM group than in the control group (61.63078 vs 39.0609, p<0.01). In contrast, there were no significant differences in superoxide dismutase (SOD) levels between groups (p>0.05). The Poisson regression analysis revealed a significant association between selenium and high levels of MDA, IL-6 and TNF-α (p<0.05). Additionally, selenium was negatively connected with SOD levels and the neutrophil/lymphocyte ratio, but this relationship was not statistically significant (p=0.96, 0.15, respectively).

Conclusion

Selenium deficiency is strongly associated with the development of ICM, and with levels of inflammation and oxidative stress in patients with ICM. Selenium can prevent the development and delay the progression of ICM by alleviating inflammatory responses.

Nutritional status in pulmonary arterial hypertension

Nutritional deficiencies have been described in patients with pulmonary arterial hypertension (PAH), such as in iron and vitamin D. However, an extensive description of vitamin and mineral status is lacking and until now there is no data on dietary intake in PAH patients. We analyzed blood samples and determined nutritional intake using a food frequency questionnaire (HELIUS) in a cohort of prevalent PAH patients at a single center in Amsterdam, the Netherlands. Quality of life (QoL) was assessed by the SF-36 questionnaire. In total, 37 patients were included (6 males, 31 females; 48 ± 16 years). The dietary intake of sugar was above 25 g in 87% of the patients and fluid intake was above 1500 ml in 78% of the patients. Sodium intake was below 1800 mg in the majority (56%) of the patients. Sugar and fluid intake were linear related. We confirm previously observed deficiencies of iron and vitamin D in our study population. In addition, we observed a functional vitamin B12 deficiency in 29% of patients, which coincided with an increased expression of methylmalonic acid. 60% of patients had a low vitamin K1 status (<0.8 nmol/L). Finally, 40% of patients had selenium levels below <100 μg/L and low selenium levels associated with reduced vitality in these patients. Besides the known deficiencies in iron and vitamin D levels, we observed in a subset of patients signs of vitamin B12, vitamin K1 and selenium deficiencies. There is room for improving dietary intake. Future research aims to demonstrate the clinical importance and reveal the effect of nutritional interventions.