Association of Serum Zinc Level With Prognosis in Patients With Heart Failure

Study of plasma essential element concentrations to explore markers of acute myocardial infarction

Essential element concentrations in biological samples may be related to the pathogenesis of various diseases. Previous studies have reported that serum iron (Fe), zinc (Zn), and copper (Cu) were related to acute myocardial infarction (AMI). However, the differences in element concentrations between AMI and other cardiac disease has not been investigated. In this study, differences in plasma Fe, magnesium (Mg), Zn, Cu, calcium (Ca), inorganic phosphorus (P), and cardiac troponin T (TnT) levels in heart disease patients (AMI, angina, heart failure, and chest pain) were investigated to explore potential markers of AMI. Fe, Mg, Zn, and Cu concentrations were assayed by using a Metallo Assay kit; Ca and inorganic P were determined by using an automatic biochemical analyzer; and cardiac TnT levels were assayed by using enzyme-linked immunosorbent assay. Plasma TnT levels were higher in AMI than in other heart diseases and were negatively correlated with Cu and Ca. Fe, Cu, and inorganic P levels were within the normal range, while Mg and Ca levels were lower, and Zn levels were higher than the normal range in heart disease patients. Except Mg, no significant differences in element levels were observed among heart diseases: Mg levels were significantly higher in AMI than in heart failure. These results suggest that lower Cu and Ca levels and a higher Mg level compared with other heart diseases may be a marker of AMI.

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.

Coordination chemistry suggests that independently observed benefits of metformin and Zn2+ against COVID-19 are not independent

Independent trials indicate that either oral Zn2+ or metformin can separately improve COVID-19 outcomes by approximately 40%. Coordination chemistry predicts a mechanistic relationship and therapeutic synergy. Zn2+ deficit is a known risk factor for both COVID-19 and non-infectious inflammation. Most dietary Zn2+ is not absorbed. Metformin is a naked ligand that presumably increases intestinal Zn2+ bioavailability and active absorption by cation transporters known to transport metformin. Intracellular Zn2+ provides a natural buffer of many protease reactions; the variable "set point" is determined by Zn2+ regulation or availability. A Zn2+-interactive protease network is suggested here. The two viral cysteine proteases are therapeutic targets against COVID-19. Viral and many host proteases are submaximally inhibited by exchangeable cell Zn2+. Inhibition of cysteine proteases can improve COVID-19 outcomes and non-infectious inflammation. Metformin reportedly enhances the natural moderating effect of Zn2+ on bioassayed proteome degradation. Firstly, the dissociable metformin-Zn2+ complex could be actively transported by intestinal cation transporters; thereby creating artificial pathways of absorption and increased body Zn2+ content. Secondly, metformin Zn2+ coordination can create a non-natural protease inhibitor independent of cell Zn2+ content. Moderation of peptidolytic reactions by either or both mechanisms could slow (a) viral multiplication (b) viral invasion and (c) the pathogenic host inflammatory response. These combined actions could allow development of acquired immunity to clear the infection before life-threatening inflammation. Nirmatrelvir (Paxlovid®) opposes COVID-19 by selective inhibition the viral main protease by a Zn2+-independent mechanism. Pending safety evaluation, predictable synergistic benefits of metformin and Zn2+, and perhaps metformin/Zn2+/Paxlovid® co-administration should be investigated.

Zinc Deficiency in Critically Ill Patients: Impact on Clinical Outcome

Background Zinc is a trace element essential for the normal functioning of many vital enzymes and organ systems. Studies examining the rates and degrees of zinc deficiency and its consequences in patients with critical illnesses remain scarce. Materials and methods This is a prospective observational study assessing zinc deficiency in critically ill adult patients admitted to a tertiary care intensive care unit (ICU) and its impact on clinical outcomes. Patients were divided into those with normal (≥ 71 µg/dl) and low (≤ 70 µg/dl) zinc levels. Zinc-deficient patients were further divided into mild, moderate, and severe zinc deficiency groups based on zinc levels of 61-70 µg/dl, 51-60 µg/dl, and below 51 µg/dl, respectively. The primary outcome assessed was ICU mortality, and the secondary outcomes were ICU length of stay (LOS), duration of invasive mechanical ventilation (IMV), acute kidney injury (AKI) at admission, need for non-invasive ventilation (NIV), renal replacement therapy (RRT), or vasopressors during the course of the ICU. Other parameters compared included APACHE (Acute Physiology and Chronic Health Evaluation) II, SOFA (Sequential Organ Failure Assessment) score on day 1, and levels of lactate, procalcitonin, calcium, magnesium, phosphate, and serum albumin. The study also compared the mean zinc levels in patients with low and high SOFA scores (scores up to 7 vs. 8 and above) and low and high APACHE II values (scores up to 15 vs. 16 and above). Results A total of 50 patients were included, of whom 43 (86%) were zinc deficient. Mortality in zinc-deficient and normal zinc-level patients was 33% and 43%, respectively (p = 0.602). Patients with zinc deficiency were also older (mean age 69 vs. 49 years, p = 0.02). There was no difference in secondary outcome parameters, except for more zinc-deficient patients needing RRT. Twenty-six of the zinc-deficient patients had severe zinc deficiency, ten moderate, and seven mild (p = 0.663). ICU mortality was approximately 42%, 10%, and 29% in the severe, moderate, and mild deficiency groups, respectively (p = 0.092). Zinc levels were similar between those with low and high APACHE II scores (mean 47.9 vs. 45.5 µg/dl, p = 0.606) as well as between low and high SOFA scores (mean 47.8 vs. 45.7 µg/dl, p = 0.054). Conclusion The present study suggests that zinc deficiency is very common in critically ill patients but does not correlate with their severity of illness, nor does it lead to a poorer outcome in these patients. However, further studies with a larger cohort of patients would be required to make definitive conclusions.

Integrative analysis of bioinformatics and machine learning to identify cuprotosis-related biomarkers and immunological characteristics in heart failure

Backgrounds

Cuprotosis is a newly discovered programmed cell death by modulating tricarboxylic acid cycle. Emerging evidence showed that cuprotosis-related genes (CRGs) are implicated in the occurrence and progression of multiple diseases. However, the mechanism of cuprotosis in heart failure (HF) has not been investigated yet.

Methods

The HF microarray datasets GSE16499, GSE26887, GSE42955, GSE57338, GSE76701, and GSE79962 were downloaded from the Gene Expression Omnibus (GEO) database to identify differentially expressed CRGs between HF patients and nonfailing donors (NFDs). Four machine learning models were used to identify key CRGs features for HF diagnosis. The expression profiles of key CRGs were further validated in a merged GEO external validation dataset and human samples through quantitative reverse-transcription polymerase chain reaction (qRT-PCR). In addition, Gene Ontology (GO) function enrichment, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment, and immune infiltration analysis were used to investigate potential biological functions of key CRGs.

Results

We discovered nine differentially expressed CRGs in heart tissues from HF patients and NFDs. With the aid of four machine learning algorithms, we identified three indicators of cuprotosis (DLAT, SLC31A1, and DLST) in HF, which showed good diagnostic properties. In addition, their differential expression between HF patients and NFDs was confirmed through qRT-PCR. Moreover, the results of enrichment analyses and immune infiltration exhibited that these diagnostic markers of CRGs were strongly correlated to energy metabolism and immune activity.

Conclusions

Our study discovered that cuprotosis was strongly related to the pathogenesis of HF, probably by regulating energy metabolism-associated and immune-associated signaling pathways.

Serum zinc concentration in patients with myocardial infarction: a retrospective study

BACKGROUND

Zinc regulates the oxidative stress and inflammatory signaling cascade and affects the development and deterioration of cardiovascular disease. We investigated the prognosis of developing heart failure in patients with myocardial infarction.

METHODS

Patients with myocardial infarction (n = 243) were divided using the median value of zinc concentration on admission into low (< 66 µg/dL at admission, n = 111) and high zinc group (≥ 66 µg/dL at admission, n = 132). During follow-up (mean ± SD: 734 ± 597 days; median 691 days), admission due to heart failure was observed in 12 patients: 10 and 2 cases in the low and high zinc groups, respectively.

RESULTS

The risk of admission due to heart failure was significantly higher in the low zinc than in the high zinc group (P = 0.0043). Relative to the high zinc group, the hazard ratio for admission due to heart failure was 15.7 (95% confidence interval 1.11-221, P = 0.042) via adjusted Cox proportional hazards analysis. Even after propensity score matching, the risk of admission due to heart failure was significantly higher in the low zinc than in the high zinc group (P = 0.048).

CONCLUSION

Low serum zinc concentration may be a risk factor for admission due to heart failure after myocardial infarction.

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.

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.

Cardiovascular Diseases and Zinc

Zinc is structurally and functionally essential for more than 300 enzymes and 2000 transcription factors in human body. Intracellular labile zinc is the metabolically effective zinc and tiny changes in its concentrations significantly affect the intracellular signaling and enzymatic responses. Zinc is crucial for the embrionic and fetal development of heart. Therefore, it is shown to be related with a variety of congenital heart defects. It is involved in epithelial-to-mesenchymal transformation including endocardial cushion development, which is necessary for atrioventricular septation as well as the morphogenesis of heart valves. In atherosclerosis, monocyte endothelial adhesion, and diapedesis, activation and transformation into macrophages and forming foam cells by the ingestion of oxidized LDL are monocyte related steps which need zinc. Intracellular zinc increases intracellular calcium through a variety of pathways and furthermore, zinc itself can work as a second messenger as calcium. These demonstrate the significance of intracellular zinc in heart failure and arterial hypertension. However, extracellular zinc has an opposite effect by blocking calcium channels, explaining decreased serum zinc levels, contrary to the increased cardiomyocyte and erythrocyte zinc levels in hypertensive subjects. These and other data in the literature demonstrate that zinc has important roles in healthy and diseased cardiovascular system but zinc-cardiovascular system relationship is so complex that, it has not been explained in all means. In this article, we try to review some of the available knowledge about this complex relationship.

A Systematic Study on Zinc-Related Metabolism in Breast Cancer

Breast cancer has become the most common cancer worldwide. Despite the major advances made in the past few decades in the treatment of breast cancer using a combination of chemotherapy, endocrine therapy, and immunotherapy, the genesis, treatment, recurrence, and metastasis of this disease continue to pose significant difficulties. New treatment approaches are therefore urgently required. Zinc is an important trace element that is involved in regulating various enzymatic, metabolic, and cellular processes in the human body. Several studies have shown that abnormal zinc homeostasis can lead to the onset and progression of various diseases, including breast cancer. This review highlights the role played by zinc transporters in pathogenesis, apoptosis, signal transduction, and potential clinical applications in breast cancer. Additionally, the translation of the clinical applications of zinc and associated molecules in breast cancer, as well as the recent developments in the zinc-related drug targets for breast cancer treatment, is discussed. These developments offer novel insights into understanding the concepts and approaches that could be used for the diagnosis and management of breast cancer.

Nutritional management of heart failure

Nutrition in the cardiovascular field to date has focused on improving lifestyle-related diseases such as hypertension and diabetes from the viewpoint of secondary prevention. For these conditions, "nutrition for weight loss" is recommended, and nutritional guidance that restricts calories is provided. On the other hand, in symptomatic Stage C and D heart failure, it is known that underweight patients who manifest poor nutrition, sarcopenia, and cardiac cachexia have a poor prognosis. This is referred to as the "Obesity paradox". In order to "avoid weight loss" in patients with heart failure, a paradigm shift to nutritional management to prevent weight loss is needed. Rather than prescribing uniform recommendation for salt reduction of 6 g/day or less, awareness of the behavior change stage model is attracting attention. In this setting, the value of salt restriction will need to be determined to determine the priority level of intervention for undernutrition versus the need to prevent congestive signs and symptoms. In the Intensive Care Unit (ICU)/Cardiac Care Unit (CCU) for acute heart failure, nutritional intervention should be considered within 48 h of admission. Key points are selection of access route, timing of intervention, and monitoring of side effects. In nutritional management at home and in end-of-life care, food is a reflection of an individual's values, as well as a source of joy and encouragement. The importance of digestive tract should also be recognized in heart failure from oral flail to intestinal edema, constipation, and the intestinal bacteria called the heart-gut axis. Finally, we would like to propose a new term "heart nutrition" for nutritional management in patients with heart failure in this review. Compared to the evidence for exercise therapy in heart failure, studies assessing nutritional management remain scarce and there is a need for research in this area in the future.

No Association of Hair Zinc Concentration with Coronary Artery Disease Severity and No Relation with Acute Coronary Syndromes

Cardiovascular diseases (CVDs) are the leading cause of death worldwide. Although zinc (Zn) was reported to have antioxidant, anti-inflammatory and protective properties in CVDs, its association with coronary artery disease (CAD) is still unclear. As methods commonly used to assess Zn levels in blood and urine do not show the full picture of the microelement supply, in this study, the nutritional status of Zn in patients with angiographically confirmed CAD was assessed using inductively coupled plasma optical emission spectrometry. We found no association between Zn and the severity of CAD evaluated with the Coronary Artery Surgery Study Score (p = 0.67). There were no statistically significant differences in Zn levels between patients with acute coronary syndrome and those with stable CAD (p = 0.937). A statically significant negative correlation was observed between Zn content and serum triglyceride concentration (p < 0.05). Patients with type 2 diabetes mellitus were found to have a significantly lower hair Zn content compared to non-diabetic individuals (p < 0.01). The role of Zn in the pathogenesis of CAD and its complications need further well-designed research as the moderation and supplementation of Zn dietary intake could be a simple intervention to reduce the CVDs risk.

Micronutrient deficiencies in heart failure: Mitochondrial dysfunction as a common pathophysiological mechanism?

Heart failure is a devastating clinical syndrome, but current therapies are unable to abolish the disease burden. New strategies to treat or prevent heart failure are urgently needed. Over the past decades, a clear relationship has been established between poor cardiac performance and metabolic perturbations, including deficits in substrate uptake and utilization, reduction in mitochondrial oxidative phosphorylation and excessive reactive oxygen species production. Together, these perturbations result in progressive depletion of cardiac adenosine triphosphate (ATP) and cardiac energy deprivation. Increasing the delivery of energy substrates (e.g., fatty acids, glucose, ketones) to the mitochondria will be worthless if the mitochondria are unable to turn these energy substrates into fuel. Micronutrients (including coenzyme Q10, zinc, copper, selenium and iron) are required to efficiently convert macronutrients to ATP. However, up to 50% of patients with heart failure are deficient in one or more micronutrients in cross-sectional studies. Micronutrient deficiency has a high impact on mitochondrial energy production and should be considered an additional factor in the heart failure equation, moving our view of the failing myocardium away from an "an engine out of fuel" to "a defective engine on a path to self-destruction." This summary of evidence suggests that supplementation with micronutrients-preferably as a package rather than singly-might be a potential therapeutic strategy in the treatment of heart failure patients.

Impact of Zinc Deficiency During Prenatal and/or Postnatal Life on Cardiovascular and Metabolic Diseases: Experimental and Clinical Evidence

This review summarizes the latest findings, from animal models and clinical studies, regarding the cardiovascular and metabolic consequences in adult life of zinc deficiency (ZD) during prenatal and early postnatal life. The effect of zinc supplementation (ZS) and new insights about sex differences in the phenotype and severity of cardiovascular and metabolic alterations are also discussed. Zinc has antioxidant, anti-inflammatory, and antiapoptotic properties and regulates the activity of enzymes involved in regulation of the metabolic, cardiovascular, and renal systems. Maternal ZD is associated with intrauterine growth restriction and low birth weight (LBW). Breast-fed preterm infants are at risk of ZD due to lower zinc uptake during fetal life and reduced gut absorption capacity. ZS is most likely to increase growth in preterm infants and survival in LBW infants in countries where ZD is prevalent. Studies performed in rats revealed that moderate ZD during prenatal and/or early postnatal growth is a risk factor for the development of hypertension, cardiovascular and renal alterations, obesity, and diabetes in adult life. An adequate zinc diet during postweaning life does not always prevent the cardiovascular and metabolic alterations induced by zinc restriction during fetal and lactation periods. Male rats are more susceptible to this injury than females, and some of the mechanisms involved include: 1) alterations in organogenesis, 2) activation of oxidative, apoptotic, and inflammatory processes, 3) dysfunction of nitric oxide and renin-angiotensin-aldosterone systems, 4) changes in glucose and lipid metabolism, and 5) adipose tissue dysfunction. Safeguarding body zinc requirements during pregnancy, lactation, and growth periods could become a new target in the prevention and treatment of cardiovascular and metabolic disorders. Further research is needed to elucidate the efficacy of ZS during early stages of growth to prevent the development of these diseases later in life.

The Prognostic Value of Serum Zinc Levels in Acutely Hospitalized Patients: a Systematic Review

Several small studies have identified possible associations between low serum zinc levels and worse outcomes in patients acutely hospitalized for a variety of diseases. This study systematically evaluated all published literature to determine whether serum zinc might independently predict important outcomes in hospitalized patients. PubMed, Embase, and Cochrane Libraries databases were searched from 1970 to 2019 to identify all citations having the keyword "zinc" with hospital outcomes. Studies were included if they measured the association between serum zinc levels in non-electively hospitalized patients with survival, length of stay, or unplanned readmission. Data were double-abstracted to evaluate the association between zinc levels and these outcomes. Our search returned 1091 citations of which 12 studies met the inclusion criteria. Studies were small (median 112.5 patients) using unspecified sampling methods. Seven studies were restricted to critically ill patients. Mean zinc levels ranged from 27.5 to 85.3 μg/dL. Baseline mean zinc levels were significantly lower (p < 0.05) in patients who eventually died in 1 of 7 studies. Five of seven studies found significantly increased risk of death in hospital with lower zinc levels. Associations between zinc levels and critical care or hospital length of stay were unclear. In 1 study, lower zinc levels were associated with a significantly increased risk of unplanned readmission. Current studies measuring the association between serum zinc levels and outcomes in acutely hospitalized patients are limited by their sample sizes, select patient populations, and limited statistical analyses. The association of zinc levels with hospital patient outcomes is unclear.

Serum Zinc and Selenium Concentrations in Patients with Hypertrophy and Remodelling of the Left Ventricle Secondary to Arterial Hypertension

The aim of the study was to assess the relationship between serum selenium and zinc concentrations (Se-S and Zn-S) and the left ventricle geometry in patients suffering from arterial hypertension. A total of 78 people with arterial hypertension (mean age: 53.72 ± 12.74 years) participated in the study. Se-S and Zn-S were determined in all patients. The type of left ventricular remodelling and hypertrophy was determined by the left ventricular mass index (LVMI) and relative wall thickness (RWT) measured by echocardiography. Se-S and Zn-S in the whole group were 89.84 ± 18.75 µg/L and 0.86 ± 0.13 mg/L. Normal left ventricular geometry was found in 28.2% of patients; left ventricular hypertrophy (LVH) in 71.8%, including concentric remodelling in 28.2%, concentric hypertrophy in 29.5%, and eccentric hypertrophy in 14.1%. LVH was statistically significantly more frequent in patients with Se-S < median compared to patients with Se-S ≥ median (87.2% vs. 56.4%, p < 0.05), as well as in patients with Zn-S < median compared to patients with Zn-S ≥ median (83.8% vs. 60.9%, p < 0.05). In hypertensive patients, older age, higher LDL cholesterol, higher fasting glucose, lower Se-S, and lower Zn-S were independently associated with LVH. In conclusion, in hypertensive patients, left ventricular hypertrophy may be associated with low levels of selenium and zinc in the serum.

Selenoprotein DIO2 Is a Regulator of Mitochondrial Function, Morphology and UPRmt in Human Cardiomyocytes

Members of the fetal-gene-program may act as regulatory components to impede deleterious events occurring with cardiac remodeling, and constitute potential novel therapeutic heart failure (HF) targets. Mitochondrial energy derangements occur both during early fetal development and in patients with HF. Here we aim to elucidate the role of DIO2, a member of the fetal-gene-program, in pluripotent stem cell (PSC)-derived human cardiomyocytes and on mitochondrial dynamics and energetics, specifically. RNA sequencing and pathway enrichment analysis was performed on mouse cardiac tissue at different time points during development, adult age, and ischemia-induced HF. To determine the function of DIO2 in cardiomyocytes, a stable human hPSC-line with a DIO2 knockdown was made using a short harpin sequence. Firstly, we showed the selenoprotein, type II deiodinase (DIO2): the enzyme responsible for the tissue-specific conversion of inactive (T4) into active thyroid hormone (T3), to be a member of the fetal-gene-program. Secondly, silencing DIO2 resulted in an increased reactive oxygen species, impaired activation of the mitochondrial unfolded protein response, severely impaired mitochondrial respiration and reduced cellular viability. Microscopical 3D reconstruction of the mitochondrial network displayed substantial mitochondrial fragmentation. Summarizing, we identified DIO2 to be a member of the fetal-gene-program and as a key regulator of mitochondrial performance in human cardiomyocytes. Our results suggest a key position of human DIO2 as a regulator of mitochondrial function in human cardiomyocytes.

Mechanisms of diabetic cardiomyopathy and potential therapeutic strategies: preclinical and clinical evidence

The pathogenesis and clinical features of diabetic cardiomyopathy have been well-studied in the past decade, but effective approaches to prevent and treat this disease are limited. Diabetic cardiomyopathy occurs as a result of the dysregulated glucose and lipid metabolism associated with diabetes mellitus, which leads to increased oxidative stress and the activation of multiple inflammatory pathways that mediate cellular and extracellular injury, pathological cardiac remodelling, and diastolic and systolic dysfunction. Preclinical studies in animal models of diabetes have identified multiple intracellular pathways involved in the pathogenesis of diabetic cardiomyopathy and potential cardioprotective strategies to prevent and treat the disease, including antifibrotic agents, anti-inflammatory agents and antioxidants. Some of these interventions have been tested in clinical trials and have shown favourable initial results. In this Review, we discuss the mechanisms underlying the development of diabetic cardiomyopathy and heart failure in type 1 and type 2 diabetes mellitus, and we summarize the evidence from preclinical and clinical studies that might provide guidance for the development of targeted strategies. We also highlight some of the novel pharmacological therapeutic strategies for the treatment and prevention of diabetic cardiomyopathy.

A Clinical Tool to Predict Low Serum Selenium in Patients with Worsening Heart Failure

Selenium is an essential micronutrient, and a low selenium concentration (<100 µg/L) is associated with a poorer quality of life and exercise capacity, and an impaired prognosis in patients with worsening heart failure. Measuring selenium concentrations routinely is laborious and costly, and although its clinical utility is yet to be proven, an easy implemented model to predict selenium status is desirable. A stepwise multivariable logistic regression analysis was performed using routinely measured clinical factors. Low selenium was independently predicted by: older age, lower serum albumin, higher N-terminal pro-B-type natriuretic peptide levels, worse kidney function, and the presence of orthopnea and iron deficiency. A 10-points risk-model was developed, and a score of ≥6 points identified >80% of patients with low selenium (sensitivity of 44%, specificity of 80%). Given that selenium and iron overlap in their physiological roles, we evaluated the shared determinants and prognostic associates. Both deficiencies shared similar clinical characteristics, including the model risk factors and, in addition, a low protein intake and high levels of C-reactive protein. Low selenium was associated with a similar or worse prognosis compared to iron deficiency. In conclusion, although it is difficult to exclude low selenium based on clinical characteristics alone, we provide a prediction tool which identifies heart failure patients at higher risk of having a low selenium status.

Factors associated with zinc levels in hospitalized patients: An observational study using routinely collected data

BACKGROUND

Zinc deficiency is easily treated and has been associated with worse outcomes in hospitalized patients. Zinc testing is time-consuming and relatively costly. We identified every zinc level measured at our teaching hospital and quantified how much zinc variation is explained by other hospital factors.

METHODS

We linked tables from our hospital data warehouse from 1996 to 2019 to identify all patients who had at least 1 serum zinc measured during their admission. We determined the status of factors that could influence zinc levels including severity of illness, presence of bleeding or inflammation, and factors influencing zinc absorption.

RESULTS

We identified only 318 adult patients having zinc measurement during their hospitalization. Patients were elderly (median age 71 [IQR 56-78]) and arrived by ambulance 45% of the time. Zinc was measured a median of 5 days into the hospitalization (IQR 3-13) with 154 (51.6%) recording a low level. Almost half of patients were missing at least one covariable laboratory test. Multilinear regression models using complete case analysis returned more extreme parameter estimate values and deemed as significant only two thirds of the factors identified as significant in models using data with missing values imputed. Imputed models found significant associations between lower zinc levels and recent surgery, decreased albumin, creatinine, and sodium, earlier hospitalization day of sampling, and increased patient comorbidity. These models explained 32% of zinc variation.

CONCLUSIONS

Zinc testing is rare, low zinc levels are very common, and one third of its variation in hospitalized patients is explained by other covariables.

Zinc Deficiency and Heart Failure: A Systematic Review of the Current Literature

Zinc is an essential micronutrient that impacts the cardiovascular system through modulation of oxidative stress. It is unknown whether zinc levels are affected in heart failure (HF), and whether the association, if present, is causal. A systematic search for publications that report coexisting zinc deficiency in patients with HF was performed to provide an overview of the pathophysiological and epidemiological aspects of this association (last search April 2019). Review of the literature suggests multiple potential pathophysiologic causes for zinc deficiency in HF as a result of impaired micronutrient consumption, hyper-inflammatory state, upregulation of the renin-angiotensin-aldosterone axis, diminished absorption, and hyperzincuria from HF medications. In a longitudinal study of patients with HF in the setting of intestinal malabsorption, there was partial cardiomyocyte and left ventricular ejection fraction recovery with intravenous selenium and zinc supplementation. Two randomized double-blind control trials evaluating micronutrient and macronutrient supplementation including zinc in patients with HF found improvement in echocardiographic findings compared with placebo. Two recently completed studies evaluated the role for zinc supplementation in 2 different HF populations: a trial of zinc supplementation in patients with non-ischemic HF, and a trial of micronutrient supplementation (including B vitamins, vitamin D, and zinc) in veterans with systolic dysfunction; the results of which are still pending. Several pathobiological pathways to link zinc deficiency with the development and deterioration of HF are presented. Preliminary clinical data are supportive of such an association and future studies should further investigate the effects of zinc supplementation on outcomes in patients with HF.

Selenium and outcome in heart failure

Aims

Severe deficiency of the essential trace element selenium can cause myocardial dysfunction although the mechanism at cellular level is uncertain. Whether, in clinical practice, moderate selenium deficiency is associated with worse symptoms and outcome in patients with heart failure is unknown.

Methods and results

BIOSTAT‐CHF is a multinational, prospective, observational cohort study that enrolled patients with worsening heart failure. Serum concentrations of selenium were measured by inductively coupled plasma mass spectrometry. Primary endpoint was a composite of all‐cause mortality and hospitalization for heart failure; secondary endpoint was all‐cause mortality. To investigate potential mechanisms by which selenium deficiency might affect prognosis, human cardiomyocytes were cultured in absence of selenium, and mitochondrial function and oxidative stress were assessed. Serum selenium concentration (deficiency) was <70 μg/L in 485 (20.4%) patients, who were older, more often women, had worse New York Heart Association class, more severe signs and symptoms of heart failure and poorer exercise capacity (6‐min walking test) and quality of life (Kansas City Cardiomyopathy Questionnaire). Selenium deficiency was associated with higher rates of the primary endpoint [hazard ratio (HR) 1.23; 95% confidence interval (CI) 1.06–1.42] and all‐cause mortality (HR 1.52; 95% CI 1.26–1.86). In cultured human cardiomyocytes, selenium deprivation impaired mitochondrial function and oxidative phosphorylation, and increased intracellular reactive oxygen species levels.

Conclusions

Selenium deficiency in heart failure patients is independently associated with impaired exercise tolerance and a 50% higher mortality rate, and impaired mitochondrial function in vitro, in human cardiomyocytes. Clinical trials are needed to investigate the effect of selenium supplements in patients with heart failure, especially if they have low plasma concentrations of selenium.

Micronutrient Depletion in Heart Failure: Common, Clinically Relevant and Treatable

Heart failure (HF) is a chronic condition with many imbalances, including nutritional issues. Next to sarcopenia and cachexia which are clinically evident, micronutrient deficiency is also present in HF. It is involved in HF pathophysiology and has prognostic implications. In general, most widely known micronutrients are depleted in HF, which is associated with symptoms and adverse outcomes. Nutritional intake is important but is not the only factor reducing the micronutrient availability for bodily processes, because absorption, distribution, and patient comorbidity may play a major role. In this context, interventional studies with parenteral micronutrient supplementation provide evidence that normalization of micronutrients is associated with improvement in physical performance and quality of life. Outcome studies are underway and should be reported in the following years.

3,5-Dicaffeoylquinic acid protects H9C2 cells against oxidative stress-induced apoptosis via activation of the PI3K/Akt signaling pathway

Background

Oxidative stress-induced apoptosis plays an important role in the development of heart failure. 3,5-Dicaffeoylquinic acid (3,5-diCQA), a phenolic compound, has shown protective effects against oxidative stress in many diseases.

Objective

The objective of this study was to investigate the anti-apoptosis potential of 3,5-diCQA in cardiomyocyte cells under oxidative stress and explore its underlying mechanisms.

Design

A model of tert-butyl hydroperoxide (TBHP)-induced apoptosis in a cardiomyocyte cell line (H9C2) was established. Cell viabilities on cell lines were determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium (MTT) assay. The apoptosis was measured by hoechst33342 and propidium iodide (PI) fluorescent staining. PI (in red) stained the regions of cell apoptosis; Hoechet33342 (in blue) stained the nuclei. The Western blot was used to determine the expressions of related proteins such as p-PI3K: phosphorylated phosphatidylinositol-3-kinase (p-PI3K), phosphorylated Serine and Threonine kinase AKT (p-AKT), p-PTEN, Bcl-2, Bax, and caspase-3. Afterward, a PI3K inhibitor, LY294002, was applied to confirm the influence of the PI3K/Akt pathway on TBHP-treated cells of 3,5-diCQA. Then, H9C2 cells were pre-incubated with 3,5-diCQA alone to determine if the expression of activated PI3K/Akt signaling was mediated by 3,5-diCQA in H9C2 cells.

Results

The results showed that TBHP resulted in an increase in cardiomyocyte apoptosis, whereas 3,5-diCQA treatment protected cells from TBHP-induced apoptosis in a dose-dependent manner. Moreover, 3,5-diCQA decreased expressions of Bax and caspase-3 but increased the phosphorylation levels of PI3K and Akt in TBHP-treated cells, which are the key molecules mediating cell survival, whereas phosphatase and tensin homologue deleted on chromosome 10 (PTEN) phosphorylation was unchanged. Importantly, pre-incubation with a PI3K inhibitor (LY294002) partly abolished the anti-apoptosis effects of 3,5-diCQA. Further, 3,5-diCQA enhanced the phosphorylation levels of PI3K and Akt in H9C2 cells directly, while LY294002 attenuated the effects of 3,5-diCQA on PI3K and Akt.

Conclusion

This study suggested that 3,5-diCQA rescued myocardium from apoptosis by increasing the activation of the PI3K/Akt signaling pathway.

Crosstalk between zinc and free fatty acids in plasma

In mammalian blood plasma, serum albumin acts as a transport protein for free fatty acids, other lipids and hydrophobic molecules including neurodegenerative peptides, and essential metal ions such as zinc to allow their systemic distribution. Importantly, binding of these chemically extremely diverse entities is not independent, but linked allosterically. One particularly intriguing allosteric link exists between free fatty acid and zinc binding. Albumin thus mediates crosstalk between energy status/metabolism and organismal zinc handling. In recognition of the fact that even small changes in extracellular zinc concentration and speciation modulate the function of many cell types, the albumin-mediated impact of free fatty acid concentration on zinc distribution may be significant for both normal physiological processes including energy metabolism, insulin activity, heparin neutralisation, blood coagulation, and zinc signalling, and a range of disease states, including metabolic syndrome, cardiovascular disease, myocardial ischemia, diabetes, and thrombosis.

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Serum albumin binds and transports both free fatty acids and Zn²⁺ ions

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Elevated plasma free fatty acids impair Zn²⁺ binding by albumin through an allosteric mechanism

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The resulting changes in plasma zinc speciation are thought to impact blood coagulation and may promote thrombosis

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Increased free Zn²⁺ may lead to enhanced zinc export from plasma and dysregulation of zinc homeostasis in multiple tissues