Micronutrients in African-Americans with decompensated and compensated heart failure

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.

The Correlation Between Whole Blood Copper (Cu), Zinc (Zn) Levels and Cu/Zn Ratio and Sepsis-Induced Left Ventricular Systolic Dysfunction (SILVSD) in Patients with Septic Shock: A Single-Center Prospective Observational Study

Purpose

This study aimed to explore relationships between whole blood copper (Cu), zinc (Zn) and Cu/Zn ratio and cardiac dysfunction in patients with septic shock.

Subjects and Methods

Between April 2018 and March 2020, septic shock patients with sepsis-induced left ventricular systolic dysfunction (SILVSD, left ventricular ejection fraction, LVEF<50%) and with no sepsis-induced myocardial dysfunction (non-SIMD, septic shock alone and LVEF>50%) and controls were prospectively enrolled. Whole blood Cu and Zn levels were measured using flame atomic absorption spectrophotometry.

Results

Eighty-six patients with septic shock including both 41 SILVSD and 45 non-SIMD and 25 controls were studied. Whole blood Cu levels and Cu/Zn ratio were significantly higher and Zn levels were lower in SILVSD compared with non-SIMD and controls (Cu, p=0.009, <0.001; Zn, p=0.029, <0.001; Cu/Zn ratio, p=0.003, <0.001). Both increased whole blood Cu and Cu/Zn ratio and reduced Zn were associated with lower LVEF (all p<0.001) and higher amino-terminal pro-B-type natriuretic peptide (NT-proBNP) (Cu, p=0.002; Zn, p<0.001; Cu/Zn ratio, p<0.001) and had predictive values for SILVSD (Cu, AUC=0.666, p=0.005; Zn, AUC=0.625, p=0.039; Cu/Zn ratio, AUC=0.674, p=0.029). Whole blood Cu levels and Cu/Zn ratio were increased but Zn levels were reduced in non-survivors compared with survivors (Cu, p<0.001; Zn, p<0.001; Cu/Zn ratio, p<0.001). Whole blood Cu and Zn displayed the value of predicting 28-day mortality (Cu, AUC = 0.802, p<0.001; Zn, AUC=0.869, p<0.001; Cu/Zn ratio, AUC=0.902, p<0.001).

Conclusion

Findings of the study suggest that whole blood Cu levels and Cu/Zn ratio are increased in SILVSD patients and positively correlated with cardiac dysfunction, while whole blood Zn levels are reduced and negatively associated with cardiac dysfunction. Moreover, both whole blood Cu, Zn and Cu/Zn ratio might distinguish between SILVSD and non-SIMD in septic shock patients and predict 28-day mortality.

Trial Registration

Registered at http://www.chictr.org.cn/ChiCTR1800015709.

Selenium, Selenoproteins, and Heart Failure: Current Knowledge and Future Perspective

PURPOSE OF REVIEW

(Mal-)nutrition of micronutrients, like selenium, has great impact on the human heart and improper micronutrient intake was observed in 30-50% of patients with heart failure. Low selenium levels have been reported in Europe and Asia and thought to be causal for Keshan disease. Selenium is an essential micronutrient that is needed for enzymatic activity of the 25 so-called selenoproteins, which have a broad range of activities. In this review, we aim to summarize the current evidence about selenium in heart failure and to provide insights about the potential mechanisms that can be modulated by selenoproteins.

RECENT FINDINGS

Suboptimal selenium levels (<100 μg/L) are prevalent in more than 70% of patients with heart failure and were associated with lower exercise capacity, lower quality of life, and worse prognosis. Small clinical trials assessing selenium supplementation in patients with HF showed improvement of clinical symptoms (NYHA class), left ventricular ejection fraction, and lipid profile, while governmental interventional programs in endemic areas have significantly decreased the incidence of Keshan disease. In addition, several selenoproteins are found impaired in suboptimal selenium conditions, potentially aggravating underlying mechanisms like oxidative stress, inflammation, and thyroid hormone insufficiency. While the current evidence is not sufficient to advocate selenium supplementation in patients with heart failure, there is a clear need for high level evidence to show whether treatment with selenium has a place in the contemporary treatment of patients with HF to improve meaningful clinical endpoints. Graphical summary summarizing the potential beneficial effects of the various selenoproteins, locally in cardiac tissues and systemically in the rest of the body. In short, several selenoproteins contribute in protecting the integrity of the mitochondria. By doing so, they contribute indirectly to reducing the oxidative stress as well as improving the functionality of immune cells, which are in particular vulnerable to oxidative stress. Several other selenoproteins are directly involved in antioxidative pathways, next to excreting anti-inflammatory effects. Similarly, some selenoproteins are located in the endoplasmic reticulum, playing roles in protein folding. With exception of the protection of the mitochondria and the reduction of oxidative stress, other effects are not yet investigated in cardiac tissues. The systemic effects of selenoproteins might not be limited to these mechanisms, but also may include modulation of endothelial function, protection skeletal muscles, in addition to thyroid metabolism.

ABBREVIATIONS

DIO, iodothyronine deiodinase; GPx, glutathione peroxidase; MsrB2, methionine-R-sulfoxide reductase B2; SELENOK, selenoprotein K; SELENON, selenoprotein N; SELENOP, selenoprotein P; SELENOS, selenoprotein S; SELENOT, selenoprotein T; TXNRD, thioredoxin reductase.

Nutraceutical support in heart failure: a position paper of the International Lipid Expert Panel (ILEP)

Heart failure (HF) is a complex clinical syndrome that represents a major cause of morbidity and mortality in Western countries. Several nutraceuticals have shown interesting clinical results in HF prevention as well as in the treatment of the early stages of the disease, alone or in combination with pharmacological therapy. The aim of the present expert opinion position paper is to summarise the available clinical evidence on the role of phytochemicals in HF prevention and/or treatment that might be considered in those patients not treated optimally as well as in those with low therapy adherence. The level of evidence and the strength of recommendation of particular HF treatment options were weighed up and graded according to predefined scales. A systematic search strategy was developed to identify trials in PubMed (January 1970 to June 2019). The terms 'nutraceuticals', 'dietary supplements', 'herbal drug' and 'heart failure' or 'left verntricular dysfunction' were used in the literature search. The experts discussed and agreed on the recommendation levels. Available clinical trials reported that the intake of some nutraceuticals (hawthorn, coenzyme Q10, l-carnitine, d-ribose, carnosine, vitamin D, probiotics, n-3 PUFA and beet nitrates) might be associated with improvements in self-perceived quality of life and/or functional parameters such as left ventricular ejection fraction, stroke volume and cardiac output in HF patients, with minimal or no side effects. Those benefits tended to be greater in earlier HF stages. Available clinical evidence supports the usefulness of supplementation with some nutraceuticals to improve HF management in addition to evidence-based pharmacological therapy.

Selenium-Rich Diet Induces Myocardial Structural and Functional Abnormalities by Activating Caspase-9 and Caspase-3 in Gpx-1P198L-Overexpression Transgenic Mice

Background

Selenium (Se) deficiency and supplementation result in multiple effects. GPx-1 (Pro198Leu) polymorphism is associated with Se deficiency. This study aimed to observe associations between Se-deficiency/supplement and GPx-1-198Leu overexpression in myocardial injuries.

Material/Methods

GPx-1P198L transgenic (Tg) mice and non-transgenic wild-type (WT) littermates were divided into Control (CON, 0.1–0.2 mg/kg), Se-deficiency (SD, <0.02 mg/kg), and Se-supplement (SS, 0.4 mg/kg) groups. Cardiac functions were observed with animal M-mode echocardiography. Se level was measured using 2,3-diamino Kenai fluorospectrophotometry. Total cardiac GPx activity was also measured. Myocardial histopathology was determined with HE and Masson’s trichrome staining. Caspase-9 and caspase-3 were measured with Western blot analysis.

Results

In WT Se-deficient mice, cardiac GPx activity was significantly decreased, and was not elevated by overexpression of GPx-1-198Leu gene. Increased GPx activity was observed in WT Se-supplemented mice and Tg Se-supplemented mice (much more). Se deficiency as well as supplementation resulted in cardiac systolic dysfunction, which was not affected by GPx-1-198Leu gene. Se deficiency led to myocardial fibrosis and pathological changes accompanied by increased activation of caspase-9 and caspase-3. Se supplementation significantly reduced pathological changes, as well as caspase-9 and caspase-3 levels in the presence of increased myocardial fibrosis. In Se-deficient mice, GPx-1-198Leu overexpression did not significantly decrease myocardial pathological injuries and fibrosis. In Se-supplemented Tg mice, myocardial fibrosis and caspase-9 level were increased, although pathological injuries and caspase-3 were similar to that in Se-supplemented WT mice.

Conclusions

Se deficiency as well as supplementation induced myocardial structural and functional abnormalities through activation of caspase-9 and caspase-3 in GPx-1P198L overexpression transgenic mice.

Vitamin D supplements reduce depressive symptoms and cardiac events in heart failure patients with moderate to severe depressive symptoms

Background:

Depressive symptoms and vitamin D deficiency predict cardiac events in heart failure patients, but whether vitamin D supplements are associated with depressive symptoms and cardiac events in heart failure patients remains unknown.

Purpose:

The purpose of this study was to compare the association of vitamin D supplement use with depressive symptoms and cardiac events in heart failure patients with mild or moderate to severe depressive symptoms.

Methods:

A total of 177 heart failure patients with depressive symptoms (Patient Health Questionnaire-9 score ≥5) completed a three-day food diary to determine dietary vitamin D deficiency. Patients were split into four groups by dietary vitamin D adequacy versus deficiency and vitamin D supplement use versus non-use. The Patient Health Questionnaire-9 was used to reassess depressive symptoms at six months. Data on cardiac events for up to one year and vitamin D supplement use were obtained from patient interview and medical record review. Hierarchical linear and Cox regressions were used for data analysis.

Results:

Sixty-six patients (37.3%) had dietary vitamin D deficiency and 80 (45.2%) used vitamin D supplements. In patients with moderate to severe depressive symptoms, the group with dietary vitamin D deficiency and no supplements had the highest Patient Health Questionnaire-9 score at six months (β=0.542, p<0.001) and shortest cardiac event-free survival ( p<0.001) among the four groups, the group with dietary vitamin D deficiency and no supplements didn’t have the highest Patient Health Questionnaire-9 score at six months and shortest cardiac event-free survival in patients with mild depressive symptoms.

Conclusions:

Vitamin D supplements predicted lower depressive symptoms and reduced cardiac events for patients with moderate to severe depressive symptoms. Vitamin D deficiency was associated with higher risk of shorter cardiac event-free survival in heart failure patients regardless of vitamin D supplementation.

Zinc and the prooxidant heart failure phenotype

Neurohormonal activation with attendant aldosteronism contributes to the clinical appearance of congestive heart failure (CHF). Aldosteronism is intrinsically coupled to Zn and Ca dyshomeostasis, in which consequent hypozincemia compromises Zn homeostasis and Zn-based antioxidant defenses that contribute to the CHF prooxidant phenotype. Ionized hypocalcemia leads to secondary hyperparathyroidism with parathyroid hormone-mediated Ca overloading of diverse cells, including cardiomyocytes. When mitochondrial Ca overload exceeds a threshold, myocyte necrosis follows. The reciprocal regulation involving cytosolic free [Zn]i as antioxidant and [Ca]i as prooxidant can be uncoupled in favor of Zn-based antioxidant defenses. Increased [Zn]i acts as a multifaceted antioxidant by: (1) inhibiting Ca entry through L-type channels and hence cardioprotectant from the Ca-driven mitochondriocentric signal-transducer effector pathway to nonischemic necrosis, (2) serving as catalytic regulator of Cu/Zn-superoxide dismutase, and (3) activating its cytosolic sensor, metal-responsive transcription factor that regulates the expression of relevant antioxidant defense genes. Albeit present in subnanomolar range, increased cytosolic free [Zn]i enhances antioxidant capacity that confers cardioprotection. It can be achieved exogenously by ZnSO4 supplementation or endogenously using a β3-receptor agonist (eg, nebivolol) that enhances NO generation to release inactive cytosolic Zn bound to metallothionein. By recognizing the pathophysiologic relevance of Zn dyshomeostasis in the prooxidant CHF phenotype and by exploiting the pharmacophysiologic potential of [Zn]i as antioxidant, vulnerable cardiomyocytes under assault from neurohormonal activation can be protected and the myocardium spared from adverse structural remodeling.

MicroRNA expression profiles in rats with selenium deficiency and the possible role of the Wnt/β-catenin signaling pathway in cardiac dysfunction

Selenium deficiency is a causative factor in heart failure and microRNAs (known as miRNAs or miRs) play an important role in numerous cardiovascular diseases. However, the changes of miRNA expression during selenium deficiency and whether selenium deficiency is involved in cardiac dysfunction remain unclear. In the present study, miRNA expression profiling was carried out in normal rats, selenium-deficient rats and selenium-supplemented rats by miRNA microarray. Cardiac function was evaluated by analyzing the plasma brain natriuretic peptide level, echocardiographic parameters and hemodynamic parameters. Cardiac glutathione peroxidase activity was assessed by spectrophotometry. The histological changes were examined by hematoxylin and eosin staining. Electrocardiograph was used to test the arrhythmia. The differentially expressed miRNAs were verified by reverse transcription-polymerase chain reaction. Additionally, the underlying mechanism associated with the Wnt/β-catenin signaling pathway was further explored. The cardiac dysfunction of the rat with selenium deficiency was mainly associated with five upregulated miRNAs, which were miR-374, miR-16, miR-199a-5p, miR-195 and miR-30e*, and three downregulated miRNAs, which were miR-3571, miR-675 and miR-450a*. Among these, the expression of miR-374 was the highest, which may be of vital importance in rats with selenium deficiency. In conclusion, the possible mechanism of selenium deficiency-induced cardiac dysfunction was associated with the Wnt/β-catenin signaling pathway.

Clinical and echocardiographic correlates of serum copper and zinc in acute and chronic heart failure

AIM

Emerging evidence suggests a pathophysiological role of micronutrient dyshomeostasis in heart failure, including promotion of adverse remodeling and clinical deterioration. We sought to evaluate serum copper (Cu) and zinc (Zn) levels in acute (AHF) and chronic (CHF) heart failure.

METHODS

We studied 125 patients, 71 % male, aged 69 ± 11 years, 37 % with preserved left ventricular ejection fraction (LVEF ≥40 %) (HFPEF), including 81 with AHF and 44 with CHF; 21 healthy volunteers served as controls. Serum Cu and Zn levels were determined using air-acetylene flame atomic absorption spectrophotometry.

RESULTS

Serum Cu levels were significantly higher in AHF (p = 0.006) and CHF (p = 0.002) patients compared to controls after adjusting for age, gender and comorbidities, whereas they did not differ between AHF and CHF (p = 0.840). Additionally, serum Cu in patients with LVEF <40 % was significantly higher compared to both controls (p < 0.001) and HFPEF patients (p = 0.003). Serum Zn was significantly lower in AHF (p < 0.001) and CHF (p = 0.039) compared to control after adjusting for the above-mentioned variables. Moreover, serum Zn was significantly lower in AHF than in CHF (p = 0.015). In multiple linear regression, LVEF (p = 0.033) and E/e ratio (p = 0.006) were independent predictors of serum Cu in total heart failure population, while NYHA class (p < 0.001) and E/e ratio (p = 0.007) were independent predictors of serum Zn.

CONCLUSION

Serum Cu was increased both in AHF and CHF and correlated with LV systolic and diastolic function. Serum Zn, in contrast, was decreased both in AHF and CHF and independently predicted by clinical status and LV diastolic function.

Selenium and cardiometabolic health: inconclusive yet intriguing evidence

Selenium is incorporated as the unique amino acid selenocysteine into selenoproteins, which regulate important biologic processes such as redox balance. The results of epidemiologic and clinical investigations are inconclusive regarding the relation of the plasma selenium level to cardiometabolic parameters and does not support the routine use of selenium supplements to prevent cancer or cardiovascular disease. Variability in the selenium status of the populations studied and lack of standardization of measures of selenium status may account for part of the confusion regarding selenium and cardiometabolic health. Another possibility is that differences in the effects of selenoproteins, as opposed to those of low-molecular-weight selenium compounds derived from in vivo metabolism of selenium, may explain the unusual phenomenon of a similar phenotype induced by both selenium deficiency and excess in experimental models and offer a plausible explanation for the lack of consistency in clinical studies. The epidemiologic, clinical, and experimental evidence, although inconclusive in terms of the precise relation of selenium to cardiometabolic health, is however very intriguing in terms of the urgent need for further mechanistic research to enable the clinical use of this potent micronutrient.

Mineralocorticoid receptor antagonism confers cardioprotection in heart failure

The symptoms and signs constituting the congestive heart failure (CHF) syndrome have their pathophysiologic origins rooted in a salt-avid renal state mediated by effector hormones of the renin-angiotensin-aldosterone and adrenergic nervous systems. Controlled clinical trials, conducted over the past decade in patients having minimally to markedly severe symptomatic heart failure, have demonstrated the efficacy of a pharmacologic regimen that interferes with these hormones, including aldosterone receptor binding with either spironolactone or eplerenone. Potential pathophysiologic mechanisms, which have not hitherto been considered involved for the salutary responses and cardioprotection provided by these mineralocorticoid receptor antagonists, are reviewed herein. In particular, we focus on the less well-recognized impact of catecholamines and aldosterone on monovalent and divalent cation dyshomeostasis, which leads to hypokalemia, hypomagnesemia, ionized hypocalcemia with secondary hyperparathyroidism and hypozincemia. Attendant adverse cardiac consequences include a delay in myocardial repolarization with increased propensity for supraventricular and ventricular arrhythmias, and compromised antioxidant defenses with increased susceptibility to nonischemic cardiomyocyte necrosis.

Vitamin D, calcium, and atherosclerotic risk: evidence from serum levels and supplementation studies

Vitamin D and calcium have traditionally been viewed in relation to bone health. However, recent research has suggested relations between these nutrients and cardiovascular disease (CVD). Specifically, evidence from both observational studies and clinical trials suggests that vitamin D may be related to lower risk of CVD. The picture for calcium is more complex. Dietary intake of calcium may be associated with lower CVD risk, while calcium supplementation may elevate CVD risk. In this review, we summarize evidence of these relations, and comment on the recent Institute of Medicine (IOM) recommendations regarding use of vitamin D and calcium supplements.

Quality and adequacy of dietary intake in a southern urban heart failure population

BACKGROUND

Few studies have examined the quality and adequacy of dietary intake in patients attempting to limit sodium.

OBJECTIVE

The aim of this study was to provide a comprehensive analysis of the dietary intake of persons with heart failure (HF) in the Southern United States who have been advised to limit their sodium intake.

METHODS

Three-day food diaries were completed by 114 New York Heart Association class II and III persons with HF enrolled in a family partnership intervention study, which were reviewed by a dietitian and analyzed using validated nutritional software. The Harris-Benedict equation for sedentary adults was used to determine macronutrient intake adequacy. Demographic information and clinical data were obtained through patient report and medical record review.

RESULTS

Dietary sodium ingestion ranged from 522 to 9251 mg/d (mean [SD], 2671 [1432] mg/d), with 38 (33.3%) individuals consuming the recommended 2000 mg/d or less in this sample (age, 28-78 years; 64.0% men; 57.0% African American). Mean (SD) caloric intake for the total sample was 1674 (636) kcal/d, with participants eating 99% of the recommended daily allowance (RDA) of protein, 63% of the RDA of carbohydrates, and 89% of the RDA of fat. Participants eating 2000 mg or less of sodium consumed significantly less calories (P < .001), protein (P < .001), carbohydrates (P = .008), and fat (P < .001), but not fiber (P = .103), compared with those consuming more than 2000 mg of sodium after adjusting for body mass index. When analyzed by amount of sodium consumption, persons ingesting 2000 mg or less of sodium per day ate significantly less grains (P = .001) and meat and beans (P = .004) and had less intake of the micronutrients calcium (P < .001), zinc (P = .002), and thiamine (P = .05).

CONCLUSION

Only one-third of participants with HF who have been instructed on a low-sodium diet reported consuming the RDA of 2000 mg or less, indicating the need for further dietary instruction with a particular focus on modifying the Southern US diet.

Selenistasis: epistatic effects of selenium on cardiovascular phenotype

Although selenium metabolism is intricately linked to cardiovascular biology and function, and deficiency of selenium is associated with cardiac pathology, utilization of selenium in the prevention and treatment of cardiovascular disease remains an elusive goal. From a reductionist standpoint, the major function of selenium in vivo is antioxidant defense via its incorporation as selenocysteine into enzyme families such as glutathione peroxidases and thioredoxin reductases. In addition, selenium compounds are heterogeneous and have complex metabolic fates resulting in effects that are not entirely dependent on selenoprotein expression. This complex biology of selenium in vivo may underlie the fact that beneficial effects of selenium supplementation demonstrated in preclinical studies using models of oxidant stress-induced cardiovascular dysfunction, such as ischemia-reperfusion injury and myocardial infarction, have not been consistently observed in clinical trials. In fact, recent studies have yielded data that suggest that unselective supplementation of selenium may, indeed, be harmful. Interesting biologic actions of selenium are its simultaneous effects on redox balance and methylation status, a combination that may influence gene expression. These combined actions may explain some of the biphasic effects seen with low and high doses of selenium, the potentially harmful effects seen in normal individuals, and the beneficial effects noted in preclinical studies of disease. Given the complexity of selenium biology, systems biology approaches may be necessary to reach the goal of optimization of selenium status to promote health and prevent disease.

Both selenium deficiency and modest selenium supplementation lead to myocardial fibrosis in mice via effects on redox-methylation balance

SCOPE

Selenium has complex effects in vivo on multiple homeostatic mechanisms such as redox balance, methylation balance, and epigenesis, via its interaction with the methionine-homocysteine cycle. In this study, we examined the hypothesis that selenium status would modulate both redox and methylation balance and thereby modulate myocardial structure and function.

METHODS AND RESULTS

We examined the effects of selenium-deficient (<0.025 mg/kg), control (0.15 mg/kg), and selenium-supplemented (0.5 mg/kg) diets on myocardial histology, biochemistry and function in adult C57/BL6 mice. Selenium deficiency led to reactive myocardial fibrosis and systolic dysfunction accompanied by increased myocardial oxidant stress. Selenium supplementation significantly reduced methylation potential, DNA methyltransferase activity and DNA methylation. In mice fed the supplemented diet, inspite of lower oxidant stress, myocardial matrix gene expression was significantly altered resulting in reactive myocardial fibrosis and diastolic dysfunction in the absence of myocardial hypertrophy.

CONCLUSION

Our results indicate that both selenium deficiency and modest selenium supplementation leads to a similar phenotype of abnormal myocardial matrix remodeling and dysfunction in the normal heart. The crucial role selenium plays in maintaining the balance between redox and methylation pathways needs to be taken into account while optimizing selenium status for prevention and treatment of heart failure.

Disturbances in calcium metabolism and cardiomyocyte necrosis: the role of calcitropic hormones

A synchronized dyshomeostasis of extra- and intracellular Ca(2+), expressed as plasma ionized hypocalcemia and excessive intracellular Ca(2+) accumulation, respectively, represents a common pathophysiologic scenario that accompanies several diverse disorders. These include low-renin and salt-sensitive hypertension, primary aldosteronism and hyperparathyroidism, congestive heart failure, acute and chronic hyperadrenergic stressor states, high dietary Na(+), and low dietary Ca(2+) with hypovitaminosis D. Homeostatic responses are invoked to restore normal extracellular [Ca(2+)](o), including increased plasma levels of parathyroid hormone and 1,25(OH)(2)D(3). However, in cardiomyocytes these calcitropic hormones concurrently promote cytosolic free [Ca(2+)](i) and mitochondrial [Ca(2+)](m) overloading. The latter sets into motion organellar-based oxidative stress, in which the rate of reactive oxygen species generation overwhelms their detoxification by endogenous antioxidant defenses, including those related to intrinsically coupled increments in intracellular Zn(2+). In turn, the opening potential of the mitochondrial permeability transition pore increases, allowing for osmotic swelling and ensuing organellar degeneration. Collectively, these pathophysiologic events represent the major components to a mitochondriocentric signal-transducer-effector pathway to cardiomyocyte necrosis. From necrotic cells, there follows a spillage of intracellular contents, including troponins, and a subsequent wound healing response with reparative fibrosis or scarring. Taken together, the loss of terminally differentiated cardiomyocytes from this postmitotic organ and the ensuing replacement fibrosis each contribute to the adverse structural remodeling of myocardium and progressive nature of heart failure. In conclusion, hormone-induced ionized hypocalcemia and intracellular Ca(2+) overloading comprise a pathophysiologic cascade common to diverse disorders and that initiates a mitochondriocentric pathway to nonischemic cardiomyocyte necrosis.

The role of micronutrients in heart failure

Heart failure is a common condition in the Western world, particularly among elderly persons and with an ever-aging population, the incidence is expected to increase. Diet in the setting of heart failure is important--patients with this condition are advised to consume a low-salt diet and monitor their weight closely. Nutritional status of patients with heart failure also is important--those with poor nutritional status tend to have a poor long-term prognosis. A growing body of evidence suggests an association between heart failure and micronutrient status. Reversible heart failure has been described as a consequence of severe thiamine and selenium deficiency. However, contemporary studies suggest that a more subtle relationship may exist between micronutrients and heart failure. This article reviews the existing literature linking heart failure and micronutrients, examining studies that investigated micronutrient intake, micronutrient status, and the effect of micronutrient supplementation in patients with heart failure, and focusing particularly on vitamin A, vitamin C, vitamin E, thiamine, other B vitamins, vitamin D, selenium, zinc, and copper.

Inorganic phosphate and FGF-23 predict outcome in stable systolic heart failure

BACKGROUND

Recent studies show associations between inorganic phosphate and risk of heart failure in the general population as well as between fibroblast growth factor 23 (FGF-23) and outcome in coronary heart disease. This study was carried out to assess whether circulating levels of inorganic phosphate and FGF-23, a new central hormone in mineral bone metabolism, predict outcome in systolic heart failure.

MATERIALS AND METHODS

Ninety-nine consecutive outpatients with systolic heart failure were enrolled. Mean (SD) age was 61 years (11), mean left ventricular ejection fraction (LVEF) was 33% (10), 82 patients were men, median estimated creatinine clearance was 83 mL/min (Q(1) -Q(3) 58-106), median NTproBNP level was 803 pg/mL (Q(1) -Q(3) 404-2757), median inorganic phosphate was 1·12 mM (Q(1) -Q(3) 1·02-1·22), median FGF-23 was 39·02 pg/mL (Q(1) -Q(3) 32·45-55·86) and median follow-up was 35 months. Associations between inorganic phosphate, FGF-23 and endpoints were assessed using Cox regression analyses.

RESULTS

Inorganic phosphate and FGF-23 levels were significantly higher (P < 0·001 and P = 0·009) in patients reaching the combined endpoint of cardiac hospitalization or death. FGF-23 (ln) predicted all-cause mortality (hazard ratio (HR) 5·042, P = 0·032) in a model adjusted for age, gender, estimated creatinine clearance, LVEF, New York Heart Association (NYHA) stage and NTproBNP level. Inorganic phosphate predicted heart failure hospitalization (HR 26·944, P = 0·021), cardiac hospitalization (HR 16·016, P = 0·017) and the combined endpoint (HR 13·294, P = 0·015) in models adjusted for the same co-variables.

CONCLUSION

The results of this study demonstrate the independent prognostic value of inorganic phosphate and FGF-23 in heart failure even in the context of established risk markers.

Stressor states and the cation crossroads

Neurohormonal activation involving the hypothalamic-pituitary-adrenal axis and adrenergic nervous and renin-angiotensin-aldosterone systems is integral to stressor state-mediated homeostatic responses. The levels of effector hormones, depending upon the degree of stress, orchestrate the concordant appearance of hypokalemia, ionized hypocalcemia and hypomagnesemia, hypozincemia, and hyposelenemia. Seemingly contradictory to homeostatic responses wherein the constancy of extracellular fluid would be preserved, upregulation of cognate-binding proteins promotes coordinated translocation of cations to injured tissues, where they participate in wound healing. Associated catecholamine-mediated intracellular cation shifts regulate the equilibrium between pro-oxidants and antioxidant defenses, a critical determinant of cell survival. These acute and chronic stressor-induced iterations in extracellular and intracellular cations are collectively referred to as the cation crossroads. Intracellular cation shifts, particularly excessive accumulation of Ca2+, converge on mitochondria to induce oxidative stress and raise the opening potential of their inner membrane permeability transition pores (mPTPs). The ensuing loss of cationic homeostasis and adenosine triphosphate (ATP) production, together with osmotic swelling, leads to organellar degeneration and cellular necrosis. The overall impact of iterations in extracellular and intracellular cations and their influence on cardiac redox state, cardiomyocyte survival, and myocardial structure and function are addressed herein.

Vitamin D deficiency in patients with congestive heart failure: mechanisms, manifestations, and management

Recent research suggests that vitamin D may play a role in cardiovascular (CV) health. Although its exact role is still debated and is a matter of controversy, vitamin D deficiency has been linked to increased prevalence of CV risk factors and events. Factors that predispose persons with congestive heart failure (CHF) to hypovitaminosis D include nutritional deficiency, decreased skin production, reduced intestinal absorption, and hepatorenal disease. It is possible that low vitamin D can in turn aggravate CHF. The extent of deficiency can be severe enough to cause hypocalcemia, secondary hyperparathyroidism, osteomalacia, and decreased bone density. No clear data exist showing improvement in CV clinical outcomes with vitamin D replacement. Screening is advocated in most patients, although benefits of replacement are most likely to accrue in those with severe lack or with abnormalities of calcium-parathyroid-bone metabolism. According to current guidelines and research, vitamin D goals of >20 ng/ml in most patients with CHF and >30 ng/ml in those with secondary hyperparathyroidism seem to be appropriate to aim for. Further research is needed to fully unravel the association among CV risk, CHF and hypovitaminosis D, and translate this knowledge into clinically meaningful management recommendations.

Cellular and molecular pathways to myocardial necrosis and replacement fibrosis

Fibrosis is a fundamental component of the adverse structural remodeling of myocardium present in the failing heart. Replacement fibrosis appears at sites of previous cardiomyocyte necrosis to preserve the structural integrity of the myocardium, but not without adverse functional consequences. The extensive nature of this microscopic scarring suggests cardiomyocyte necrosis is widespread and the loss of these contractile elements, combined with fibrous tissue deposition in the form of a stiff in-series and in-parallel elastic elements, contributes to the progressive failure of this normally efficient muscular pump. Cellular and molecular studies into the signal-transducer-effector pathway involved in cardiomyocyte necrosis have identified the crucial pathogenic role of intracellular Ca2+ overloading and subsequent induction of oxidative stress, predominantly confined within its mitochondria, to be followed by the opening of the mitochondrial permeability transition pore that leads to the destruction of these organelles and cells. It is now further recognized that Ca2+ overloading of cardiac myocytes and mitochondria serves as a prooxidant and which is counterbalanced by an intrinsically coupled Zn2+ entry serving as antioxidant. The prospect of raising antioxidant defenses by increasing intracellular Zn2+ with adjuvant nutriceuticals can, therefore, be preferentially exploited to uncouple this intrinsically coupled Ca2+ - Zn2+ dyshomeostasis. Hence, novel yet simple cardioprotective strategies may be at hand that deserve to be further explored.

Cation dyshomeostasis and cardiomyocyte necrosis: the Fleckenstein hypothesis revisited

An ongoing loss of cardiomyocytes to apoptotic and necrotic cell death pathways contributes to the progressive nature of heart failure. The pathophysiological origins of necrotic cell loss relate to the neurohormonal activation that accompanies acute and chronic stressor states and which includes effector hormones of the adrenergic nervous system. Fifty years ago, Albrecht Fleckenstein and coworkers hypothesized the hyperadrenergic state, which accompanies such stressors, causes cardiomyocyte necrosis based on catecholamine-initiated excessive intracellular Ca(2+) accumulation (EICA), and mitochondrial Ca(2+) overloading in particular, in which the ensuing dysfunction and structural degeneration of these organelles leads to necrosis. In recent years, two downstream factors have been identified which, together with EICA, constitute a signal-transducer-effector pathway: (i) mitochondria-based induction of oxidative stress, in which the rate of reactive oxygen metabolite generation exceeds their rate of detoxification by endogenous antioxidant defences; and (ii) the opening of the mitochondrial inner membrane permeability transition pore (mPTP) followed by organellar swelling and degeneration. The pathogenesis of stress-related cardiomyopathy syndromes is likely related to this pathway. Other factors which can account for cytotoxicity in stressor states include: hypokalaemia; ionized hypocalcaemia and hypomagnesaemia with resultant elevations in parathyroid hormone serving as a potent mediator of EICA; and hypozincaemia with hyposelenaemia, which compromise antioxidant defences. Herein, we revisit the Fleckenstein hypothesis of EICA in leading to cardiomyocyte necrosis and the central role played by mitochondria.

Congestive heart failure: where homeostasis begets dyshomeostasis

Despite today's standard of care, aimed at preventing homeostatic neurohormonal activation, one in every five patients recently hospitalized with congestive heart failure (CHF) will be readmitted within 30 days of discharge because of a recurrence of their symptoms and signs. In light of recent pathophysiological insights, it is now propitious to revisit CHF with a view toward complementary and evolving management strategies. CHF is a progressive systemic illness. Its features include: oxidative stress in diverse tissues; an immunostimulatory state with circulating proinflammatory cytokines; a wasting of soft tissues; and a resorption of bone. Its origins are rooted in homeostatic mechanisms gone awry to beget dyshomeostasis. For example, marked excretory losses of Ca2+ and Mg2+ accompany renin-angiotensin-aldosterone system activation, causing ionized hypocalcemia and hypomagnesemia that lead to secondary hyperparathyroidism with consequent bone resorption and a propensity to atraumatic fractures. Parathyroid hormone accounts for paradoxical intracellular Ca2+ overloading in diverse tissues and consequent systemic induction of oxidative stress. In cardiac myocytes and mitochondria, these events orchestrate opening of the mitochondrial permeability transition pore with an ensuing osmotic-based destruction of these organelles and resultant cardiomyocyte necrosis with myocardial scarring. Contemporaneous with Ca2+ and Mg2+ dyshomeostasis is hypozincemia and hyposelenemia, which compromise metalloenzyme-based antioxidant defenses, whereas hypovitaminosis D threatens Ca2+ stores needed to prevent secondary hyperparathyroidism. An intrinsically coupled dyshomeostasis of intracellular Ca2+ and Zn2+, representing pro-oxidant and antioxidant, respectively, is integral to regulating the mitochondrial redox state; it can be uncoupled by a Zn2+ supplement in favor of antioxidant defenses. Hence, the complementary use of nutriceuticals to nullify dyshomeostatic responses involving macro- and micronutrients should be considered. Evolving strategies with mitochondria-targeted interventions interfering with their uptake of Ca2+ or serving as selective antioxidant or mitochondrial permeability transition pore inhibitor may also prove efficacious in the overall management of CHF.

Vitamin D deficiency and myocardial diseases

Vitamin D deficiency is common among patients with myocardial diseases because sun-induced vitamin D production in the skin and dietary intake of vitamin D is often insufficient. Knockout mice for the vitamin D receptor develop myocardial hypertrophy and dysfunction. It has also been shown that children with rickets who suffered from severe heart failure could be successfully treated with supplementation of vitamin D plus calcium. In adults, almost all patients with heart failure exhibit reduced 25-hydroxyvitamin D levels, which are used to classify the vitamin D status. In prospective studies, vitamin D deficiency was an independent risk factor for mortality, deaths due to heart failure and sudden cardiac death. Several vitamin D effects on the electrophysiology, contractility, and structure of the heart suggest that vitamin D deficiency might be a causal factor for myocardial diseases. Data from interventional trials, however, are rare and urgently needed to elucidate whether vitamin D supplementation is useful for the treatment of myocardial diseases. In our opinion, the current knowledge of the beneficial effects of vitamin D on myocardial and overall health strongly argue for vitamin D supplementation in all vitamin D-deficient patients with or at high risk for myocardial diseases.

Calcium and zinc dyshomeostasis during isoproterenol-induced acute stressor state

Acute hyperadrenergic stressor states are accompanied by cation dyshomeostasis, together with the release of cardiac troponins predictive of necrosis. The signal-transducer-effector pathway accounting for this pathophysiological scenario remains unclear. We hypothesized that a dyshomeostasis of extra- and intracellular Ca2+ and Zn2+ occurs in rats in response to isoproterenol (Isop) including excessive intracellular Ca2+ accumulation (EICA) and mitochondrial [Ca2+]m-induced oxidative stress. Contemporaneously, the selective translocation of Ca2+ and Zn2+ to tissues contributes to their fallen plasma levels. Rats received a single subcutaneous injection of Isop (1 mg/kg body wt). Other groups of rats received pretreatment for 10 days with either carvedilol (C), a β-adrenergic receptor antagonist with mitochondrial Ca2+ uniporter-inhibiting properties, or quercetin (Q), a flavonoid with mitochondrial-targeted antioxidant properties, before Isop. We monitored temporal responses in the following: [Ca2+] and [Zn2+] in plasma, left ventricular (LV) apex, equator and base, skeletal muscle, liver, spleen, and peripheral blood mononuclear cells (PBMC), indices of oxidative stress and antioxidant defenses, mitochondrial permeability transition pore (mPTP) opening, and myocardial fibrosis. We found ionized hypocalcemia and hypozincemia attributable to their tissue translocation and also a heterogeneous distribution of these cations among tissues with a preferential Ca2+ accumulation in the LV apex, muscle, and PBMC, whereas Zn2+ declined except in liver, where it increased corresponding with upregulation of metallothionein, a Zn2+-binding protein. EICA was associated with a simultaneous increase in tissue 8-isoprostane and increased [Ca2+]m accompanied by a rise in H2O2 generation, mPTP opening, and scarring, each of which were prevented by either C or Q. Thus excessive [Ca2+]m, coupled with the induction of oxidative stress and increased mPTP opening, suggests that this signal-transducer-effector pathway is responsible for Isop-induced cardiomyocyte necrosis at the LV apex.

A dyshomeostasis of electrolytes and trace elements in acute stressor states: impact on the heart

Acute stressor states are associated with a homeostatic activation of the hypothalamic-pituitary-adrenal axis. A hyperadrenergic state follows and leads to a dyshomeostasis of several intra- and extracellular cations, including K, Mg, and Ca. Prolongation of myocardial repolarization and corrected QT interval (QTc) of the ECG are useful biomarkers of hypokalemia and/or hypomagnesemia and should be monitored to address the adequacy of cation replacement. A dyshomeostasis of several trace elements, including Zn and Se, are also found in critically-ill patients to compromise metalloenzyme-based antioxidant defenses. Collectively, dyshomeostasis of these electrolytes and trace elements have deleterious consequences on the myocardium: atrial and ventricular arrhythmias; induction of oxidative stress with reduced antioxidant defenses; and adverse myocardial remodeling, including cardiomyocytes lost to necrosis and replaced by fibrous tissue. To minimize such consequences during hyperadrenergic states, systematic surveillance of electrolytes and trace elements, together with QTc, are warranted. Plasma K and Mg should be maintained at > or =4.0 mEq/L and > or =2.0 mg/dL, respectively (the 4 and 2 rule).

Nutritional inadequacies in patients with stable heart failure

Sodium restriction is the primary nutritional strategy in heart failure; however, other diet-related concerns may also occur. We characterized dietary intake among stable patients with heart failure and a non-heart-failure cardiac control group to quantify and determine prevalence of inadequate micronutrient intake. Two 3-day food records were completed by 123 patients with heart failure and 58 controls. A subset of each group provided two 24-hour urine collections. Mean intake of sodium (2,540+/-1,122 vs 2,596+/-1,184 mg/day) and potassium (3,190+/-980 vs 3,114+/-828 mg/day) was similar between the heart failure and control groups. Prevalence of inadequate potassium intake was 94% among patients with heart failure and 91% among controls. More than 50% in each group had inadequate intakes of calcium, magnesium, folate, and vitamins D and E. In stable patients with heart failure, sodium intake was not excessive. However, we demonstrated widespread dietary inadequacies of other vitamins and minerals. These findings highlight the importance of diet beyond that of sodium restriction.

Levels of vitamin D and cardiometabolic disorders: systematic review and meta-analysis

Cardiometabolic disorders and vitamin D deficiency are becoming increasingly more prevalent across multiple populations. Different studies have suggested a potential association between abnormal vitamin D levels and multiple pathological conditions including cardiovascular diseases and diabetes. We aimed to evaluate the association between vitamin D levels, using 25-hydroxy vitamin D (25OHD) as an indicator of vitamin D status, and the presence of cardiometabolic disorders including cardiovascular disease, diabetes and metabolic syndrome. We performed a systematic review of the current literature on vitamin D and cardiometabolic disorders using the PubMed and Web of Knowledge databases in September 2009. Studies in adults looking at the effect of vitamin D levels on outcomes relating to cardiometabolic disorders were selected. We performed a meta-analysis to assess the risk of developing cardiometabolic disorders comparing the highest and lowest groups of serum 25OHD. From 6130 references we identified 28 studies that met our inclusion criteria, including 99,745 participants. There was moderate variation between the studies in their grouping of 25OHD levels, design and analytical approach. We found that the highest levels of serum 25OHD were associated with a 43% reduction in cardiometabolic disorders [OR 0.57, 95% (CI 0.48-0.68)]. Similar levels were observed, irrespective of the individual cardiometabolic outcome evaluated or study design. High levels of vitamin D among middle-age and elderly populations are associated with a substantial decrease in cardiovascular disease, type 2 diabetes and metabolic syndrome. If the relationship proves to be causal, interventions targeting vitamin D deficiency in adult populations could potentially slow the current epidemics of cardiometabolic disorders.

Nutrient dyshomeostasis in congestive heart failure

The clinical syndrome congestive heart failure (CHF) has its origins rooted in a salt-avid state mediated largely by effector hormones of the renin-angiotensin-aldosterone system. In recent years, this cardiorenal perspective of CHF has taken on a broader perspective. One which focuses on a progressive systemic illness, whose major features include the presence of oxidative stress in diverse tissues and elevated circulating levels of proinflammatory cytokines coupled with a wasting of soft tissues and bone. Experimental studies, which simulate chronic renin-angiotensin-aldosterone system activation, and translational studies in patients with salt avidity having decompensated biventricular failure with hepatic and splanchnic congestion have forged a broader understanding of this illness and the important contribution of a dyshomeostasis of Ca2+, Mg2+, Zn2+, Se2+, and vitamins D, B12, and B1. Herein, we review biomarkers indicative of the nutrient imbalance found in CHF and raise the question of a need for a polynutrient supplement in the overall management of CHF.

Causes and consequences of systemic venous hypertension

The causes of systemic venous hypertension (SVHT) include cardiac- and circulatory-related factors, whereas its consequences include the congestion of hepatic, splanchnic, and peripheral circulations, which contribute significantly to the clinical congestive heart failure syndrome. Based on a disequilibrium in hydrostatic and oncotic pressures, the increased filtration and formation of interstitial fluid at these sites with an accompanying increase in lymph flow mandates an increment in lymphatic drainage to protect against such congestion and the appearance of edema and ascites. However, lymph flow via the thoracic duct into systemic veins is opposed by elevations in central venous pressure. Various management strategies have the potential to prevent and/or correct SVHT. The case of a 54-year-old man with a dilated cardiomyopathy who presented with decompensated biventricular failure, expressed as anasarca and ascites, is used to illustrate the importance of SVHT.

Causes and consequences of zinc dyshomeostasis in rats with chronic aldosteronism

Iterations in Ca2+ and Mg2+ balance accompany aldosteronism (inappropriate for dietary Na+ intake). Increased Zn excretion and Zn translocation to injured tissues, including the heart, also occurs. Several causes and consequences of Zn dyshomeostasis in rats receiving aldosterone/salt treatment (ALDOST) were examined. (1) To study the role of urinary acidification in promoting hyperzincuria, acetazolamide (75 mg/kg), a carbonic anhydrase inhibitor, was used as cotreatment to raise urinary HCO3 excretion. (2) To assess Zn levels in the heart, including cardiomyocyte cytosolic free [Zn2+]i and mitochondrial Zn, the expression of metallothionein (MT-I), a Zn binding protein, and biomarkers of oxidative stress were examined. (3) Oxidative stress and cardiac pathology in response to ZnSO4 supplement (40 mg/d) were also studied. Comparison of controls and rats receiving 4 weeks ALDOST revealed the following: (1) an acidification of urine and metabolic alkalosis associated with increased urinary Zn excretion and hypozincemia, each of which were prevented by acetazolamide; (2) a rise in cardiac Zn, including increased [Zn2+]i and mitochondrial Zn, associated with increased tissue MT-I, 8-isoprostane, malondialdehyde, and gp91(phox), coupled with oxidative stress in plasma and urine; (3) ZnSO4 prevented hypozincemia, but not ionized hypocalcemia, and attenuated oxidative stress and microscopic scarring without preventing the vasculitis and perivascular fibrosis of intramural coronary arteries. Thus, the hyperzincuria seen with ALDOST is due to urinary acidification. The oxidative stress that appears in the heart is accompanied by increased tissue Zn serving as an antioxidant. Cotreatment with ZnSO4 attenuated cardiomyocyte necrosis; however, polynutrient supplement may be required to counteract the dyshomeostasis of all 3 cations that accompanies aldosteronism and contributes to cardiac pathology.

Endothelial dysfunction in African-Americans

The journey of atherosclerosis begins with endothelial dysfunction and culminates into its most fearful destination producing ischemia, myocardial infarction and death. The excess cardiovascular disease morbidity and mortality in African-Americans is one of the major public health problems. In this review, we discuss vascular endothelial dysfunction as a key element for excess cardiovascular disease burden in this target population. It can be logical window of future atherosclerotic outcomes, and further efforts should be made to detect it at the earliest in African American individuals even if they are appearing healthy as the therapeutic interventions if instituted early, might prevent the subsequent cardiac events.

Macro- and micronutrient dyshomeostasis in the adverse structural remodelling of myocardium

Hypertension and heart failure are worldwide health problems of ever-increasing proportions. A failure of the heart, during either systolic and/or diastolic phases of the cardiac cycle, has its origins rooted in an adverse structural, biochemical, and molecular remodelling of myocardium that involves its cellular constituents, extracellular matrix, and intramural coronary vasculature. Herein we focus on the pathogenic role of a dyshomeostasis of several macro- (i.e. Ca(2+) and Mg(2+)) and micronutrients (i.e. Zn(2+), Se(2+), and vitamin D) in contributing to adverse remodelling of the myocardium and its failure as a pulsatile muscular pump. An improved understanding of how these macro- and micronutrients account for the causes and consequences of adverse myocardial remodelling carries with it the potential of identifying new biomarkers predictive of risk, onset and progression, and response to intervention(s), which could be monitored non-invasively and serially over time. Moreover, such incremental knowledge will serve as the underpinning to the development of novel strategies aimed at preventing and/or regressing the ongoing adverse remodelling of myocardium. The time is at hand to recognize the importance of macro- and micronutrient dyshomeostasis in the evaluation and management of hypertension and heart failure.

Tissue 65Zinc translocation in a rat model of chronic aldosteronism

Zinc, an essential micronutrient, is involved in wound healing. The hypozincemia seen with chronic aldosteronism is associated with enhanced fecal and urinary excretory Zn losses, and its tissue distribution is less certain. This study monitored tissue 65Zn distribution in uninephrectomized rats at weeks 1 and 4 of aldosterone/salt treatment (ALDOST). Plasma and tissue total radionucleotide uptake was determined by calculating its mean radioactivity at 1, 4, 8, 24, and 48 hours after intravenous 65Zn administration and where respective area under the concentration-time curves (AUC) were determined by the linear trapezoidal rule and expressed as a tissue:plasma AUC ratio. Examined tissues included: (1) injured heart and kidney in response to ALDOST and incised skin; (2) noninjured liver, skeletal muscle, and spleen sites of stress-linked Zn uptake; and (3) bone, a major storage and release site when Zn homeostasis is threatened. In comparison with age-matched and gender-matched controls, the following were found with week 1 and 4 ALDOST: (1) reduced plasma 65Zn; (2) an accumulation of 65Zn in heart and kidneys, where a well-known vasculopathy involves intramural vessels, and in incised skin at week 1; (3) an organ-specific increase in tissue 65Zn in liver, in keeping with upregulated metallothionein expression, skeletal muscle, and spleen; and (4) a fall in bone and healed skin Zn at week 4. Thus a wide-ranging disturbance in Zn homeostasis appears during ALDOST to include its translocation from plasma to injured heart, kidneys, and skin and noninjured liver, skeletal muscle, and spleen together with a resorption of stored Zn in bone at week 4. Zinc dyshomeostasis is an integral feature of chronic aldosteronism.

Congestive heart failure is a systemic illness: a role for minerals and micronutrients

Congestive heart failure (CHF) is a clinical syndrome that features a failing heart together with signs and symptoms arising from renal retention of salt and water, mediated by attendant neurohormonal activation, and which prominently includes the renin-angiotensin-aldosterone system. More than this cardiorenal perspective, CHF is accompanied by a systemic illness whose features include an altered redox state in diverse tissues and blood, an immunostimulatory state with proinflammatory cytokines and activated lymphocytes and monocytes, and a wasting of tissues that includes muscle and bone. Based on experimental studies of aldosteronism and clinical findings in patients with CHF, there is an emerging body of evidence that secondary hyperparathyroidism is a covariant of CHF. The aldosteronism of CHF predisposes patients to secondary hyperparathyroidism because of a chronic increase in Ca(2+) and Mg(2+) losses in urine and feces, with a fall in their serum ionized levels and consequent secretion of parathyroid hormone. Secondary hyperparathyroidism accounts for bone resorption and contributes to a fall in bone strength that can lead to nontraumatic fractures. The long-term use of a loop diuretic with its attendant urinary wasting of Ca(2+) and Mg(2+) further predisposes patients to secondary hyperparathyroidism and attendant bone loss. Aberrations in minerals and micronutrient homeostasis that includes Ca(2+), Mg(2+), vitamin D, zinc and selenium appear to be an integral component of pathophysiologic expressions of CHF that contributes to its systemic and progressive nature. This broader perspective of CHF, which focuses on the importance of secondary hyperparathyroidism and minerals and micronutrients, raises the prospect that dietary supplements could prove remedial in combination with the current standard of care.

Zinc dyshomeostasis in rats with aldosteronism. Response to spironolactone

Zinc is a structural constituent of many proteins, including Cu/Zn superoxide dismutase (SOD), an endogenous antioxidant enzyme. Hypozincemia has been found in patients hospitalized with congestive heart failure, where neurohormonal activation, including the renin-angiotensin-aldosterone system (RAAS), is expected and oxidative stress is present. This study was undertaken to elucidate potential pathophysiological mechanisms involved in Zn dyshomeostasis in aldosteronism. In rats receiving aldosterone/salt treatment (ALDOST) alone for 1 and 4 wk or in combination with spironolactone (Spiro), an ALDO receptor antagonist, we monitored 24-h urinary and fecal Zn excretion and tissue Zn levels in heart, liver, and skeletal muscle, together with tissue metallothionein (MT)-I, a Zn(2+)-binding protein, and Cu/Zn-SOD activities in plasma and tissues. When compared with unoperated, untreated, age-/sex-matched controls, urinary and, in particular, fecal Zn losses were markedly increased (P < 0.05) at days 7 and 28 of ALDOST, leading to hypozincemia and a fall (P < 0.05) in plasma Cu/Zn-SOD activity. Microscopic scars and perivascular fibrosis of intramural coronary arteries first appeared in the right and left ventricles at week 4 of ALDOST and were accompanied by increased (P < 0.05) tissue Zn, MT-I, and Cu/Zn-SOD activity, which were not found in uninjured liver or skeletal muscle. Spiro cotreatment prevented cardiac injury and Zn redistribution to the heart. Thus increased urinary and fecal Zn losses, together with their preferential translocation to sites of cardiac injury, where MT-I overexpression and increased Cu/Zn-SOD activity appeared, contribute to Zn dyshomeostasis in rats with aldosteronism, which were each prevented by Spiro. These findings may shed light on Zn dyshomeostasis found in patients with decompensated heart failure.

Macro- and micronutrients in African-Americans with heart failure

An emerging body of evidence suggests secondary hyperparathyroidism (SHPT) may be an important covariant of congestive heart failure (CHF), especially in African-Americans (AA) where hypovitaminosis D is prevalent given that melanin, a natural sunscreen, mandates prolonged exposure of skin to sunlight and where a housebound lifestyle imposed by symptomatic CHF limits outdoor activities and hence sunlight exposure. In addition to the role of hypovitaminosis D in contributing to SHPT is the increased urinary and fecal losses of macronutrients Ca(2+) and Mg(2+) associated with the aldosteronism of CHF and their heightened urinary losses with furosemide treatment of CHF. Thus, a precarious Ca(2+) balance seen with reduced serum 25(OH)D is further compromised when AA develop CHF with circulating RAAS activation and are then treated with a loop diuretic. SHPT accounts for a paradoxical Ca(2+) overloading of diverse tissues and the induction of oxidative stress at these sites which spills over to the systemic circulation. In addition to SHPT, hypozincemia and hyposelenemia have been found in AA with compensated and decompensated heart failure and where an insufficiency of these micronutrients may have its origins in inadequate dietary intake, altered rates of absorption or excretion and/or tissue redistribution, and treatment with an ACE inhibitor or AT(1) receptor antagonist. Zn and Se deficiencies, which compromise the activity of several endogenous antioxidant defenses, could prove contributory to the severity of heart failure and its progressive nature. These findings call into question the need for nutriceutical treatment of heart failure and which is complementary to today's pharmaceuticals, especially in AA.