Association of COVID-19 mortality with serum selenium, zinc and copper: Six observational studies across Europe

Selenium, diabetes, and their intricate sex-specific relationship

Selenium (Se) is an essential trace element, which is inserted as selenocysteine (Sec) into selenoproteins during biosynthesis, orchestrating their expression and activity. Se is associated with both beneficial and detrimental health effects; deficient supply or uncontrolled supplementation raises concerns. In particular, Se was associated with an increased incidence of type 2 diabetes (T2D) in a secondary analysis of a randomized controlled trial (RCT). In this review, we discuss the intricate relationship between Se and diabetes and the limitations of the available clinical and experimental studies. Recent evidence points to sexual dimorphism and an association of Se deficiency with gestational diabetes mellitus (GDM). We highlight the emerging evidence linking high Se status with improved prognosis in patients with T2D and lower risk of macrovascular complications.

Comment on Ambra et al. Could Selenium Supplementation Prevent COVID-19? A Comprehensive Review of Available Studies. Molecules 2023, 28, 4130

The authors of this Comment are longstanding selenium investigators with a total of 200 or more published articles on selenium; the corresponding author (Margaret P [...].

Demographic and clinical characteristics of patients with zinc deficiency: analysis of a nationwide Japanese medical claims database

Zinc deficiency, affecting more than 2 billion people globally, poses a significant public health burden due to its numerous unfavorable effects, such as impaired immune function, taste and smell disorders, pneumonia, growth retardation, visual impairment, and skin disorders. Despite its critical role, extensive large-scale studies investigating the correlation between patient characteristics and zinc deficiency still need to be completed. We conducted a retrospective, cross-sectional observational study using a nationwide Japanese claims database from January 2019 to December 2021. The study population included 13,100 patients with available serum zinc concentration data, excluding individuals under 20 and those assessed for zinc concentrations after being prescribed zinc-containing medication. Significant associations with zinc deficiency were noted among older adults, males, and inpatients. Multivariate analysis, adjusting for age and sex, indicated significant associations with comorbidities, including pneumonitis due to solids and liquids with an adjusted Odds Ratio (aOR) of 2.959; decubitus ulcer and pressure area (aOR 2.403), sarcopenia (aOR 2.217), COVID-19 (aOR 1.889), and chronic kidney disease (aOR 1.835). Significant association with medications, including spironolactone (aOR 2.523), systemic antibacterials (aOR 2.419), furosemide (aOR 2.138), antianemic preparations (aOR 2.027), and thyroid hormones (aOR 1.864) were also found. These results may aid clinicians in identifying patients at risk of zinc deficiency, potentially improving care outcomes.

The Anti-Oxidative, Anti-Inflammatory, Anti-Apoptotic, and Anti-Necroptotic Role of Zinc in COVID-19 and Sepsis

Zinc is a structural component of proteins, functions as a catalytic co-factor in DNA synthesis and transcription of hundreds of enzymes, and has a regulatory role in protein-DNA interactions of zinc-finger proteins. For many years, zinc has been acknowledged for its anti-oxidative and anti-inflammatory functions. Furthermore, zinc is a potent inhibitor of caspases-3, -7, and -8, modulating the caspase-controlled apoptosis and necroptosis. In recent years, the immunomodulatory role of zinc in sepsis and COVID-19 has been investigated. Both sepsis and COVID-19 are related to various regulated cell death (RCD) pathways, including apoptosis and necroptosis. Lack of zinc may have a negative effect on many immune functions, such as oxidative burst, cytokine production, chemotaxis, degranulation, phagocytosis, and RCD. While plasma zinc concentrations decline swiftly during both sepsis and COVID-19, this reduction is primarily attributed to a redistribution process associated with the inflammatory response. In this response, hepatic metallothionein production increases in reaction to cytokine release, which is linked to inflammation, and this protein effectively captures and stores zinc in the liver. Multiple regulatory mechanisms come into play, influencing the uptake of zinc, the binding of zinc to blood albumin and red blood cells, as well as the buffering and modulation of cytosolic zinc levels. Decreased zinc levels are associated with increasing severity of organ dysfunction, prolonged hospital stay and increased mortality in septic and COVID-19 patients. Results of recent studies focusing on these topics are summarized and discussed in this narrative review. Existing evidence currently does not support pharmacological zinc supplementation in patients with sepsis or COVID-19. Complementation and repletion should follow current guidelines for micronutrients in critically ill patients. Further research investigating the pharmacological mechanism of zinc in programmed cell death caused by invasive infections and its therapeutic potential in sepsis and COVID-19 could be worthwhile.

The Diagnostic Value of Trace Metal Concentrations in Hair in Carotid Artery Disease

Several studies showed the role of trace elements in the increase in human susceptibility to cardiovascular diseases. Carotid artery stenosis is a leading cause of ischemic neurological events. We aimed to analyze the potential role of trace elements in hair as biomarkers of atherosclerotic carotid artery disease. Materials and Methods: Fifty-seven (n = 31 (54%) men and n = 26 (46%) women) individuals with a mean age of 67.7 ± 7.7 years who were white, European, non-Hispanic, and non-Latino were diagnosed and treated in hypertensiology/internal medicine and surgical departments over three consecutive months. Of these patients, forty were diagnosed with advanced carotid artery disease, and seventeen comprised a group of healthy controls. Inflammatory and oncological diseases were exclusion criteria. Hair samples were collected, and 14 trace elements were analyzed. Clinical and laboratory data were compared and revealed differences in the co-existence of diabetes (p = 0.036) and smoking history (p = 0.041). In the multivariable analysis, zinc, chrome, and copper revealed predictive value for the occurrence of carotid artery disease, and their combined receiver operating curve showed area under the curve of 0.935, with a sensitivity of 95% and a specificity of 82.4%. Conclusion: Our report shows the significance of trace elements analyses in patients with advanced carotid artery disease. We revealed that zinc, copper, and chrome concentrations are of particular importance in differentiating atherosclerotic disease and may serve as biomarkers of carotid atherosclerosis. Hair samples represent an easily obtained and beneficial biomatrix for the assessment of biomarkers.

Combined copper and zinc deficiency is associated with reduced SARS-CoV-2 immunization response to BNT162b2 vaccination

The essential trace elements copper, selenium and zinc are of relevance for immunity and immune response to vaccination. In this longitudinal study, adult healthcare workers (n = 126) received two doses of an mRNA vaccine (BNT162b2), and longitudinal serum samples were prepared. Vaccine-induced antibodies and their neutralizing activity were analyzed, and the trace elements copper, zinc, and selenium along with the copper transporter ceruloplasmin were measured. Subjects with combined deficiency of copper and zinc, i.e. both in the lowest tertiles at baseline, displayed particularly low antibody titers at three (Double Q1: 13 AU/mL vs. not double Q1: 29 AU/mL) and six (Double Q1: 200 AU/mL vs. not double Q1: 425 AU/mL) weeks after vaccination (p < 0.05). The results indicate the potential importance of an adequate trace element status of copper and zinc for raising a strong vaccine-induced SARS-CoV-2 antibody response, and highlights the importance of considering combined micronutrient insufficiencies, as single deficiencies may synergize.

Association of Trace Element Levels with Outcomes in Critically Ill COVID-19 Patients

The primary objective of this study was to compare the plasma levels of copper, selenium, and zinc between critically ill COVID-19 patients and less severe COVID-19 patients. The secondary objective was to investigate the association of these trace element levels with adverse outcomes, including the duration of mechanical ventilation, occurrence of septic shock, and mortality in critically ill COVID-19 patients. All COVID-19 patients admitted to the ICU of the Geneva University Hospitals between 9 March 2020 and 19 May 2020 were included in the study. Plasma levels of copper, selenium and zinc were measured on admission to the ICU and compared with levels measured in COVID-19 patients hospitalized on the ward and in non-hospitalized COVID-19 patients. To analyze the association of trace elements with clinical outcomes, multivariate linear and logistic regressions were performed. Patients in the ICU had significantly lower levels of selenium and zinc and higher levels of copper compared to COVID-19 patients hospitalized on the ward and in non-hospitalized COVID-19 patients. In ICU patients, lower zinc levels tended to be associated with more septic shock and increased mortality compared to those with higher zinc levels (p = 0.07 for both). Having lower copper or selenium levels was associated with a longer time under mechanical ventilation (p = 0.01 and 0.04, respectively). These associations remained significant in multivariate analyses (p = 0.03 for copper and p = 0.04 for selenium). These data support the need for interventional studies to assess the potential benefit of zinc, copper and selenium supplementation in severe COVID-19 patients.

Micronutrients, genetics and COVID-19

PURPOSE OF REVIEW

Marked inter-individual differences in the clinical manifestation of coronavirus disease 2019 (COVID-19) has initiated studies in the field of genetics. This review evaluates recent genetic evidence (predominantly in the last 18 months) related to micronutrients (vitamins and trace elements) and COVID-19.

RECENT FINDINGS

In patients infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), altered circulating levels of micronutrients may serve as prognostic markers of disease severity. Mendelian randomization (MR) studies did not find significant effect of variable genetically predicted levels of micronutrients on COVID-19 phenotypes, however, recent clinical studies on COVID-19 point out to vitamin D and zinc supplementation as a nutritional strategy to reduce disease severity and mortality. Recent evidence also points to variants in vitamin D receptor ( VDR ) gene, most notably rs2228570 (FokI) "f" allele and rs7975232 (ApaI) "aa" genotype as poor prognostic markers.

SUMMARY

Since several micronutrients were included in the COVID-19 therapy protocols, research in the field of nutrigenetics of micronutrients is in progress. Recent findings from MR studies prioritize genes involved in biological effect, such as the VDR gene, rather than micronutrient status in future research. Emerging evidence on nutrigenetic markers may improve patient stratification and inform nutritional strategies against severe COVID-19.

COVID-19 in Adult Patients with Hematological Malignancies-Lessons Learned after Three Years of Pandemic

The COVID-19 pandemic is undoubtedly the most difficult health challenge of the 21st century with more than 600 million laboratory-confirmed SARS-CoV-2 infections and over 6.5 million deaths worldwide. The coronavirus pandemic contributed to rapid development of mRNA vaccines, which, along with new antiviral drugs, have been the subject of extensive research for many decades. Nevertheless, elderly, multi-morbid and immunocompromised patients continue to face a more severe clinical course and a higher risk of death from COVID-19, even now that the risk of COVID-19 in the general population is significantly reduced due to the introduction of global vaccination strategies. In this paper, we present the mechanisms of increased susceptibility to infectious complications and the evolution of the clinical course of COVID-19 in patients with hematological malignancies, taking into account the mutation of the virus and the introduction of vaccines and new antiviral drugs. We also present current recommendations for prophylactic and therapeutic management in patients with hematological malignancies.

Measurement of trace elements in murine liver tissue samples: Comparison between ICP-MS/MS and TXRF

BACKGROUND

Trace elements exhibit essential functions in many physiological processes. Thus, for research focusing on trace element homeostasis and metabolism analytical methods allowing for multi-element analyses are fundamental. Small sample amounts may be a big challenge in trace element analyses especially if also other end points want to be addressed in the same sample. Therefore, the aim of the present study was to examine trace elements (iron, copper, zinc, and selenium) in murine liver tissue prepared by a RIPA buffer-based lyses method.

METHODS AND RESULTS

After centrifugation, lysates and pellets were obtained and trace elements were analyzed with TXRF in liver lysates. The results were compared to that obtained by a standard microwave-assisted acidic digestion with subsequent ICP-MS/MS analysis of the same liver tissue, liver lysates, and remaining pellets. In addition, trace element concentrations, determined in murine serum with both methods, were compared. For serum samples, both TXRF and ICP-MS/MS provide similar and highly correlating results. Furthermore, in liver lysate samples prepared with RIPA buffer, comparable trace element concentrations were measured by TXRF as with the standard digestion technique and ICP-MS/MS. Only marginal amounts of trace elements were detected in the pellets.

CONCLUSION

Taken together, the results obtained by the present study indicate that the RIPA buffer-based method is suitable for sample preparation for trace element analyses via TXRF, at least for the here investigated murine liver samples.

COVID-19 Severity Is Associated with Selenium Intake among Young Adults with Low Selenium and Zinc Intake in North Carolina

Background

The effects of coronavirus disease 2019 (COVID-19) remain a global public health emergency because of the ensuing economic burden and death. With robust research into vaccines, antibody treatments, and antiviral drugs for COVID-19, there is still a dearth of evidence on the role of an individual's nutritional status on the severity of COVID-19.

Objective

This study aimed to investigate the association between selenium (Se) and zinc (Zn) status and COVID-19 severity among individuals diagnosed with COVID-19 in North Carolina.

Methods

Subjects (n = 106) were recruited remotely as part of the Nutrition and COVID-19 in North Carolina (NC-NC) study and filled out online screening questionnaires and dietary surveys. Toenail samples from 97 participants were analyzed to determine Se and Zn concentrations. To assess the severity of severe acute respiratory coronavirus (SARS-CoV)-2 infection, subjects were asked about the presence and duration of 10 commonly reported symptoms. These responses were used to calculate a COVID-19 severity index (CSI). The relationship between Se and Zn status (intake and toenail concentrations) and CSI was explored using a regression analysis.

Results

Our results showed that the median (25th, 75th percentiles) dietary Se and Zn intake from selected food sources were 65.2 μg (43.2, 112.9) and 4.3 mg (1.8, 8), respectively. Headache, cough, loss of smell or taste, and fever were reported by at least half of the participants. In stepwise regression analysis, among individuals with low Se and Zn intake (below the median), Se intake was inversely associated with increasing CSI (β = -0.66; 95% CI: -1.21, -0.11; P = 0.02).

Conclusions

Findings from this study support a potential benefit of increasing the intake of dietary Se to mitigate the severity of SARS-CoV-2 infection.

Obesity and dysregulated innate immune responses: impact of micronutrient deficiencies

Obesity is associated with the development of various complications, including diabetes, atherosclerosis, and an increased risk for infections, driven by dysfunctional innate immune responses. Recent insights have revealed that the availability of nutrients is a key determinant of innate immune cell function. Although the presence of obesity is associated with overnutrition of macronutrients, several micronutrient deficiencies, including Vitamin D and zinc, are often present. Micronutrients have been attributed important immunomodulatory roles. In this review, we summarize current knowledge of the immunomodulatory effects of Vitamin D and zinc. We also suggest future lines of research to further improve our understanding of these micronutrients; this may serve as a stepping-stone to explore micronutrient supplementation to improve innate immune cell function during obesity.

High throughput drug screening identifies resveratrol as suppressor of hepatic SELENOP expression

INTRODUCTION

Selenium (Se) is an essential trace element that exerts its effects mainly as the proteinogenic amino acid selenocysteine within a small set of selenoproteins. Among all family members, selenoprotein P (SELENOP) constitutes a particularly interesting protein as it serves as a biomarker and serum Se transporter from liver to privileged tissues. SELENOP expression is tightly regulated by dietary Se intake, inflammation, hypoxia and certain substances, but a systematic drug screening has hitherto not been performed.

METHODS

A compound library of 1861 FDA approved clinically relevant drugs was systematically screened for interfering effects on SELENOP expression in HepG2 cells using a validated ELISA method. Dilution experiments were conducted to characterize dose-responses. A most potent SELENOP inhibitor was further characterized by RNA-seq analysis to assess effect-associated biochemical pathways.

RESULTS

Applying a 2-fold change threshold, 236 modulators of SELENOP expression were identified. All initial hits were replicated as biological triplicates and analyzed for effects on cell viability. A set of 38 drugs suppressed SELENOP expression more than three-fold, among which were cancer drugs, immunosuppressants, anti-infectious drugs, nutritional supplements and others. Considering a 90% cell viability threshold, resveratrol, vidofludimus, and antimony potassium-tartrate were the most potent substances with suppressive effects on extracellular SELENOP concentrations. Resveratrol suppressed SELENOP levels dose-dependently in a concentration range from 0.8 μM to 50.0 μM, without affecting cell viability, along with strong effects on key genes controlling metabolic pathways and vesicle trafficking.

CONCLUSION

The results highlight an unexpected direct effect of the plant stilbenoid resveratrol, known for its antioxidative and health-promoting effects, on the central Se transport protein. The suppressive effects on SELENOP may increase liver Se levels and intracellular selenoprotein expression, thereby conferring additional protection to hepatocytes at the expense of systemic Se transport. Further physiological effects from this interaction require analyses in vivo and by clinical studies.