Serum level of copper in patients with coronary artery disease

High Copper Intake Is Associated with Decreased Likelihood of Abdominal Aortic Calcification in Middle-Aged and Older US Adults

The purpose of our study was primarily to investigate the relationship between dietary copper intake and abdominal aortic calcification (AAC) in US adults. We used data from the National Health and Nutrition Examination Survey (NHANES) 2013-2014 for our analysis. Multivariate linear regression analysis was used to explore the relationship between copper intake and AAC scores. We also used multivariate logistic regression analysis to explore the association between copper intake and the risk of AAC and severe AAC. We also examined whether there was a nonlinear relationship between copper intake and AAC scores and risk of AAC and severe AAC using restricted cubic splines (RCS) analysis. In addition, we also performed subgroup analysis and interaction tests. A total of 2897 participants were recruited in this study. The mean AAC score of the participants was 1.46 ± 0.11, and the prevalence of AAC and severe AAC among the participants was 28.53% and 7.68%, respectively. In the fully adjusted model, a negative association of copper intake with AAC scores (β =  - 0.16, 95%CI: - 0.49 ~ 0.17) and the risk of AAC (OR = 0.85, 95% CI: 0.61-1.19) and severe AAC (OR = 0.82, 95% CI: 0.49-1.38) was observed. Compared to participants in the lowest tertile of copper intake, participants in the highest tertile of copper intake had a 0.37-unit decrease in mean AAC score (β =  - 0.37, 95% CI: - 0.90-0.15) and a significant 38% and 22% decrease in risk of AAC (OR = 0.62, 95% CI: 0.41-0.95) and severe AAC (OR = 0.78, 95% CI: 0.34 - 1.77), respectively. The results of subgroup analyses and interaction tests suggested no significant differences in AAC scores and AAC risk between the different strata. In contrast, the risk of severe AAC was significantly dependent on the patients' diabetes status. Increased copper intake was associated with decreased AAC scores and decreased likelihood of AAC and severe AAC.

Ceruloplasmin, Vitamin C, and Uric Acid Levels in Patients With Myocardial Infarction: A Comparative Cross-Sectional Study

INTRODUCTION

Global mortality is significantly influenced by myocardial infarction. Scientists have examined the role of the copper-containing protein ceruloplasmin in heart attacks. It helps to regulate oxidative stress, iron metabolism, and inflammation. Vitamin C's antioxidative qualities lend credence to the idea that it could help prevent cardiovascular disease. Several studies have shown that elevated uric acid levels are related to a higher risk of myocardial infarction. With this background, we conducted this study to estimate levels of ceruloplasmin, vitamin C, and uric acid in patients with myocardial infarction.

MATERIALS AND METHODS

A tertiary care hospital in central India carried out this comparative cross-sectional study. The study was conducted between December 2022 and April 2023. Patients of any gender with newly diagnosed myocardial infarction who received admission to the intensive care unit and had ST-segment elevation of at least 2 mm in two or more consecutive electrocardiogram leads were included in the patient group. The control group consisted of individuals who did not exhibit any changes associated with myocardial infarction. Based on sex, age, and body mass index, the 75 control and 75 patients were matched. Ceruloplasmin, vitamin C, and uric acid were analyzed and compared.

RESULTS

The uric acid levels among the patient group were 10.34 ± 3.23 mg/dL, and among the controls, they were 3.45 ± 1.12 mg/dL (p<0.001). The ceruloplasmin levels among the patient group were 64.34 ± 4.21 mg/dL, and among the controls, they were 29.23 ± 3.82 mg/dL (p<0.001). The vitamin C levels among the patient group were 13.80 ± 0.94 μmol/L, and among the controls, they were 45.62 ± 4.34 μmol/L (p<0.001).

CONCLUSION

The patients with myocardial infarction demonstrated significantly elevated levels of ceruloplasmin and uric acid, while their vitamin C levels were lower in comparison. It is crucial to comprehend the underlying mechanisms through which these parameters influence the development of myocardial infarction.

Association of multiple blood metals and systemic atherosclerosis: A cross-sectional study in the CAD population

BACKGROUND

Coronary atherosclerotic disease (CAD) is often accompanied by peripheral atherosclerosis, resulting in a higher risk of ischemia and cardiovascular death. Exposure to metals is associated with atherosclerotic plaques at specific sites. However, less is known about the effects of mixed metals on systemic atherosclerotic burden in CAD patients.

OBJECTIVES

To investigate the association of metal mixtures with systemic atherosclerotic burden in a CAD population.

METHODS

A cross-sectional study including 1562 CAD patients from Southwest China was conducted. The levels of 10 blood metals were measured via inductively coupled plasma spectrometry. More than one vessel with a stenosis ≥50% vessel diameter was defined as CAD. Carotid and lower limb atherosclerosis was assessed by using ultrasound, and coronary atherosclerosis was quantified via arterial angiography. Systemic atherosclerosis was scored according to the presence or absence of lesions at the three sites and the total number of lesions. To investigate the combined impacts and interaction effects of metals, Bayesian kernel machine regression was used. Weighted quantile regression was used to identify the contributions of the metals.

RESULTS

Significant overall associations of mixed metals with systemic atherosclerotic burden were found. These positive overall associations were mainly driven by Cd, Cu and Pb in systemic atherosclerosis. The main contributing factors were As and Cu for coronary atherosclerosis as well as Cd, Cu and Pb for carotid and lower limb atherosclerosis. Cd and Pb or Cr can interact, and Pb interacts with age, sex and alcohol.

CONCLUSIONS

In CAD patients, exposure to combinations of metals was highly positively associated with systemic atherosclerotic burden. These significant trends were more pronounced in the peripheral arteries and carotid arteries. Controlling environmental metal exposure can contribute to reducing systemic atherosclerosis in CAD patients.

Relationship between Copper, Zinc, and Copper-to-Zinc Ratio in Hair and Severity of Coronary Artery Disease according to the SYNTAX Score

Coronary artery disease (CAD) continues to be a foremost contributor to global mortality, and the quest for modifiable risk factors could improve prophylactic strategies. Recent studies suggest a significant role of zinc (Zn) and copper (Cu) deficiency in atheromatous plaque formation. Furthermore, hair was previously described as a valuable source of information on elemental burden during the 6-8 week period before sampling. The aim of this study was to investigate the possibility of correlation between the extent of CAD evaluated with the SYNergy Between PCI With TAXUS and the Cardiac Surgery (SYNTAX) score with Cu and Zn content in hair samples, as well as with the Cu/Zn ratio in a cohort of 130 patients. Our findings describe a statistically significant inverse correlation between Cu content and the Cu/Zn ratio in hair samples and the extent of CAD. In contrast, no significant correlation was found between Zn content and the extent of CAD. Considering the scarcity of existing data on the subject, the analysis of hair samples could yield a novel insight into elemental deficiencies and their potential influence on CAD extent.

Copper homeostasis and cuproptosis in cardiovascular disease therapeutics

Copper (Cu) homeostasis is gaining increasing attention in human health as both Cu overload and deficiency evokes pathological changes including cardiovascular diseases (CVDs). Cu supplementation, nanocarriers, and chelators have all exhibited therapeutic promise in some human diseases, although how Cu dyshomeostasis and cuproptosis, a novel form of regulated cell death, contribute to CVD pathology remains elusive. Here, we discuss Cu dyshomeostasis and the potential role of cuproptosis in various CVDs. We evaluate underlying cellular mechanisms, aiming to provide some insights regarding the utility of targeting Cu dyshomeostasis and cuproptosis as a novel strategy in the management of CVDs.

Identification of Three Cuproptosis-specific Expressed Genes as Diagnostic Biomarkers and Therapeutic Targets for Atherosclerosis

Atherosclerosis is a chronic, inflammatory disease characterized by a lipid-driven infiltration of inflammatory cells in large and medium arteries and is considered to be a major underlying cause of cardiovascular diseases. Cuproptosis, a novel form of cell death, is highly linked to mitochondrial metabolism and mediated by protein lipoylation. However, the clinical implication of cuproptosis-related genes (CRGs) in atherosclerosis remains unclear. In this study, genes collected from the GEO database intersected with CRGs were identified in atherosclerosis. GSEA, GO and KEGG pathway enrichment analyses were performed for functional annotation. Through the random forest algorithm and the construction of a protein-protein interaction (PPI) network, eight selected genes (LOXL2, SLC31A1, ATP7A, SLC31A2, COA6, UBE2D1, CP and SOD1) and a vital cuproptosis-related gene FDX1 were then further validated. Two independent datasets (GSE28829 (N = 29), GSE100927 (N = 104)) were collected to construct the signature of CRGs for validation in atherosclerosis. Consistently, the atherosclerosis plaques showed significantly higher expression of SLC31A1, SLC31A2 and lower expression of SOD1 than the normal intimae. The area under the curve (AUC) of SLC31A1, SLC31A2 and SOD1 performed well for the diagnostic validation in the two datasets. In conclusion, the cuproptosis-related gene signature could serve as a potential diagnostic biomarker for atherosclerosis and may offer novel insights into the treatment of cardiovascular diseases. Based on the hub genes, a competing endogenous RNA (ceRNA) network of lncRNA-miRNA-mRNA and a transcription factor regulation network were ultimately constructed to explore the possible regulatory mechanism in atherosclerosis.

The molecular mechanisms of cuproptosis and its relevance to cardiovascular disease

Recently, cuproptosis has been demonstrated to be a new non-apototic cell death mode that is characterized by copper dependence and the regulation of mitochondrial respiration. Cuproptosis is distinct from known cell death modes such as apoptosis, necrosis, pyroptosis, or ferroptosis. Excessive copper induces cuproptosis by promoting protein toxic stress reactions via copper-dependent anomalous oligomerization of lipoylation proteins in the tricarboxylic acid (TCA) cycle and reducing iron-sulfur cluster protein levels. Ferredoxin1 (FDX1) promotes dihydrolipoyl transacetylase (DLAT) lipoacylation and abates iron-sulfur cluster proteins by reducing Cu²⁺ to Cu⁺, inducing cell death. Copper homeostasis depends on the copper transporter, and disturbances to this homeostasis cause cuproptosis. Recent evidence has shown that cuproptosis plays a significant role in the occurrence and development of many cardiovascular diseases, such as myocardial ischemia/reperfusion (I/R) injury, heart failure, atherosclerosis, and arrhythmias. Copper chelators, such as ammonium tetrathiomolybdate(VI) and DL-Penicillamine, may ease the above cardiovascular diseases by inhibiting the cuproptosis pathway. Oxidative phosphorylation inhibitors may inhibit cuproptosis by inhibiting protein stress response. In conclusion, cuproptosis plays an essential role in cardiovascular disease pathogenesis. Inhibition of cardiovascular cuproptosis is expected to become a potential treatment. Here, we will thoroughly review the molecular mechanisms involved in cuproptosis and its significance in cardiovascular disease.

Plasma metallomics reveals potential biomarkers and insights into the ambivalent associations of elements with acute myocardial infarction

Acute myocardial infarction (AMI) is a leading cause of mortality and morbidity worldwide. Using a validated and efficient ICP-MS/MS-based workflow, a total of 30 metallomic features were profiled in a study comprising 101 AMI patients and 66 age-matched healthy controls. The metallomic features include 12 essential elements (Ca, Co, Cu, Fe, K, Mg, Mn, Na, P, S, Se, Zn), 8 non-essential/toxic elements (Al, As, Ba, Cd, Cr, Ni, Rb, Sr, U, V), and 10 clinically relevant element-pair product/ratios (Ca/Mg, Ca×P, Cu/Se, Cu/Zn, Fe/Cu, P/Mg, Na/K, Zn/Se). Preliminary linear regression with feature selection confirmed smoking status as a predominant determinant for the non-essential/toxic elements, and revealed potential routes of action. Univariate assessments with adjustments for covariates revealed insights into the ambivalent relationships of Cu, Fe, and P with AMI, while also confirming cardioprotective associations of Se. Also, beyond their roles as risk factors, Cu and Se may be involved in the response mechanism in AMI onset/intervention, as demonstrated via longitudinal data analysis with 2 additional time-points (1-/6-month follow-up). Finally, based on both univariate tests and multivariate classification modelling, potentially more sensitive markers measured as element-pair ratios were identified (e.g., Cu/Se, Fe/Cu). Overall, metallomics-based biomarkers may have utility for AMI prediction.

Plasma Copper Concentration Is Associated with Cardiovascular Mortality in Male Kidney Transplant Recipients

Kidney transplant recipients (KTR) are at increased risk of cardiovascular mortality. We investigated whether, in KTR, post-transplantation copper status is associated with the risk of cardiovascular mortality and potential effect modification by sex. In this cohort study, plasma copper was measured using mass spectrometry in extensively-phenotyped KTR with a functioning allograft >1-year. Cox regression analyses with the inclusion of multiplicative interaction terms were performed. In 660 KTR (53 ± 13 years old, 56% male), the median baseline plasma copper was 15.42 (IQR 13.53-17.63) µmol/L. During a median follow-up of 5 years, 141 KTR died, 53 (38%) due to cardiovascular causes. Higher plasma copper was associated with an increased risk of cardiovascular mortality in the overall KTR population (HR 1.37; 95% CI, 1.07-1.77 per 1-SD, p = 0.01). Sex was a significant effect modifier of this association (P_interaction = 0.01). Among male KTR, higher plasma copper concentration was independently associated with a two-fold higher risk of cardiovascular mortality (HR 2.09; 95% CI, 1.42-3.07 per 1-SD, p < 0.001). Among female KTR, this association was absent. This evidence offers a rationale for considering a sex-specific assessment of copper's role in cardiovascular risk evaluation. Further studies are warranted to elucidate whether copper-targeted interventions may decrease cardiovascular mortality in male KTR.

Comparison of serum copper levels between coronary artery disease patients and normal individuals: a case-control study

Cardiovascular diseases (CVD) are the leading causes of death in technologically developed and developing countries. Copper, an active redox element, is involved in energy production through various mechanisms. Copper and coronary artery disease can be associated directly, through its direct effect on the vascular endothelium, or indirectly through lipoprotein metabolism. Hence an evaluation of copper in the coronary artery disease individual is important. The aim is to compare the relationship of serum copper levels between coronary artery disease patients and control individuals based on age, sex, hypertension and diabetes mellitus. Materials and methods: The study design was a case-control study in which proven coronary artery disease patients attending cardiology OPD were selected as cases. Control individuals were mainly selected from the master health check-up. Serum copper levels, plasma glucose, cholesterol, serum triglycerides, and serum HDL & LDL cholesterol were done. Glycated haemoglobin (HbA1C) was also measured. The data were analyzed using IBM SPSS software version 24. Result: The correlation of serum copper level with other quantitative parameters is determined by calculating Pearson’s correlation coefficient among cases and controls. Conclusion: The serum copper level is significantly (p=0.001) higher in CAD patients than in age, sex, DM, and HT-matched controls. The serum copper level has a significant (p=0.001) effect on disease, and the adjusted odds ratio is 1.032 (CI 1.011–1.054). In addition, the serum copper level has a significant (0.01) negative correlation with LDL cholesterol and total cholesterol.

Exploring the Link Between the Serum/Blood Levels of Heavy Metals (Pb, As, Cd, and Cu) and 2 Novel Biomarkers of Cardiovascular Stress (Growth Differentiation Factor 15 and Soluble Suppression of Tumorigenicity 2) in Copper Smelter Workers

OBJECTIVE

Studying the association between the occupational exposure to Pb, As, Cd, and Cu with the serum levels of 2 novel biomarkers of cardiovascular stress; growth differentiation factor 15 and soluble suppression of tumorigenicity 2, in some Egyptian Cu smelter workers.

METHODS

Forty-one exposed workers and 41 administrative controls were clinically evaluated. Serum/blood levels of heavy metals and biomarkers were measured for both groups.

RESULTS

The smelter workers showed significantly elevated levels of heavy metals and biomarkers compared with controls. The elevated serum levels of both biomarkers were significantly and positively correlated with each other, the levels of heavy metals, and the duration of employment of the exposed workers.

CONCLUSIONS

There was a significant association between the levels of heavy metals and both biomarkers among the smelter workers. Further prospective studies should be performed.

Dietary copper intake and the prevalence of kidney stones among adult in the United States: A propensity score matching study

Background

Trace metals are essential trace elements for the human body, but insufficient or excessive levels of metal ions can lead to the development of disease. The purpose of this study was to examine the relationship between dietary intake of copper and the prevalence of kidney stones in U.S. adult population.

Methods

We included data on dietary intake of trace metals from 28,623 adult participants in the National Health and Nutrition Examination Survey (NHANES) database between 2007 and 2018. Multivariate logistic regression and restricted cubic spline (RCS) dose-response curves were used to explore the association between trace metals and kidney stones, and 1:1 propensity score matching (PSM) was performed between the stone formers and non-stone formers to test the validity of the results.

Results

Dose-response curves showed a non-linear negative association between dietary copper intake and kidney stones, and an increase in copper intake reduced the risk of kidney stones. Multivariate logistic regression analysis showed that the odds ratio (95% confidence interval) for kidney stones in each quartile of copper intake compared to the lowest quartile were 0.905 (0.808-1.011, p = 0.075), 0.880 (0.785-0.987, p = 0.028) and 0.853 (0.756-0.959, p = 0.009). In addition, similar conclusions were reached after analysis of PSM in the stone formers and non-stone formers groups.

Conclusion

Dietary copper intake was negatively and non-linearly correlated with kidney stones, which is worthy of further research and application in clinical practice.

Copper exposure for 30 days at a daily dose twice the recommended increases blood pressure and cardiac contractility

Copper is an essential factor for the body's homeostasis. However, excess copper compromises organic functions.

AIMS

We investigated the effects of copper exposure for 30 days on blood pressure (BP) and cardiac contractility and the putative involvement of nitric oxide (NO) and reactive oxygen species.

MAIN METHODS

Wistar rats (12 weeks old, 280 g) were randomized to the treated group that was exposed for 30 days to copper (2000 μg/kg/day CuCl₂) and the control (Ct) group that received intraperitoneal saline (0.9%).

KEY FINDINGS

The blood concentration of copper was ~1.26 μg/mL in the copper-exposed group and ~0.024 μg/mL in the Ct group. The main metal accumulations occurred in the liver and kidneys. Copper exposure increased systolic BP (Cu: 141 ± 3 mmHg; Ct: 133 ± 3 mmHg) (tail cuff method), left ventricular systolic pressure and papillary muscle force. Calcium release from the sarcoplasmic reticulum was reduced. The contractile response to Ca²⁺ was increased by copper, and the effect was not altered by L-NAME. Copper increased contractions dependent on sarcolemmal Ca²⁺ influx, and this effect was not altered by L-NAME. The percentage response to isoproterenol decreased in the copper-exposed group, but L-NAME did not alter this reduction. Papillary force development at the peak and plateau of tetanic contractions also increased after copper exposure, but this effect was not altered by L-NAME. In situ detection of OH local production increased.

SIGNIFICANCE

Copper increased BP and cardiac force, increased Ca²⁺ inflow, reduced Ca²⁺ reuptake by the sarcoplasmic reticulum, and increased OH local production. Copper exposure at doses considered tolerable affects cardiac contractility.

Dietary Copper Intake and Risk of Stroke in Adults: A Case-Control Study Based on National Health and Nutrition Examination Survey 2013-2018

The association between dietary copper intake and the risk of stroke is unknown. We included a total of 10,550 participants from the National Health and Nutrition Examination Survey (NHANES) 2013−2018. Two 24-h dietary recalls and a standard questionnaire were used to determine copper intake and stroke, respectively. We used logistic regression models to estimate the associations between dietary copper intake and the risk of stroke. The nearest-neighbor propensity score matching (PSM) with a ratio of 1:2 was used to reduce selection bias. The non-linear relationship was explored with restricted cubic splines (RCS). The correlation between copper intake and baseline characteristics was detected by the Pearson correlation coefficient. The median dietary copper intake was 1.072 mg/day (IQR = 1.42−0.799). Approximately 3.8% (399) of the participants had a history of stroke. A multivariate logistic regression analysis before and after matching showed that subjects in the higher quartile had significantly lower odds of stroke compared with subjects in the first quartile of copper intake. A stratified analysis showed that copper intake was a significant protective factor for women, individuals <65 years old, individuals with hypertension, individuals who smoke, and diabetic stroke patients. The RCS models showed an L-shaped nonlinear relationship (p for nonlinear < 0.001) between copper intake and stroke. Our results suggested that increased dietary copper intake was associated with a lower risk of stroke.

Dietary Cholesterol Supplements Disturb Copper Homeostasis in Multiple Organs in Rabbits: Aorta Copper Concentrations Negatively Correlate with the Severity of Atherosclerotic Lesions

Dietary cholesterol causes atherosclerosis along with a reduction of copper concentrations in the atherosclerosis wall. This study was to determine the relationship between aorta copper concentrations and the severity of atherosclerotic lesions as well as copper homeostasis in multiple organs in cholesterol-fed rabbits. Male New Zealand white rabbits, 10-week-old and averaged 2.0 kg, were fed a diet containing 1% (w/w) cholesterol or the same diet without cholesterol as controls. Twelve weeks after the feeding, aortic atherosclerotic lesions, serum cholesterol, and multiple organ copper concentrations were measured. Compared to controls, rabbits fed cholesterol-supplemented diet displayed higher serum cholesterol levels and developed atherosclerosis. Copper concentrations in the cholesterol-fed rabbits were increased in the serum and kidney but decreased in the atherosclerosis wall and multiple organs, including heart, liver, spleen, and lung. Furthermore, aorta copper concentrations negatively correlated, respectively, with the severity of the atherosclerotic lesion (r = - 0.64, p = 0.01), the microscope atherosclerotic lesion area (r = - 0.60, p = 0.02), and the stenosis of the lumen (r = - 0.54, p = 0.04). Dietary cholesterol not only causes atherosclerosis but also disturbs copper homeostasis in multiple organ systems. The negative correlation between aorta copper concentrations and the severity of atherosclerotic lesions suggests a vicious cycle between copper reduction and the pathogenesis of atherosclerosis. These changes in copper homeostasis would be additive to atherosclerosis as a risk factor for cardiovascular disease in humans.

Trace Element and Mineral Levels in Serum, Hair, and Urine of Obese Women in Relation to Body Composition, Blood Pressure, Lipid Profile, and Insulin Resistance

The objective of this study was to evaluate serum, hair, and urinary trace element and mineral content in normal-weight and obese women in relation to metabolic risk factors. A total of 80 women aged 30–70 y.o. were enrolled in the obese group (n = 40) and normal-weight group (n = 40). Serum, hair, and urinary trace element and mineral levels were assessed using inductively coupled plasma spectrometry. Body fat percentage was evaluated using bioimpedance. Obese subjects were characterized by significantly higher body fat percentage, blood pressure, serum triglyceride concentration, and insulin resistance. Serum Ca, Fe, Mg, Se, V, Zn levels, hair Fe, Mg, V content, and urinary Se and V concentrations were found to be lower in obese subjects as compared to lean controls. In turn, serum Cu and urinary Fe levels in obese women were characterized by a significant increase. In multiple regression models serum Cu, Se, and Zn levels were significantly associated with BMI even after adjustment for blood biochemistry, body composition, and blood pressure. Serum trace element and mineral levels also significantly contributed to group discrimination. These findings allow to propose that obesity-associated disturbances in trace element and mineral status may at least partially contribute to metabolic risk in obese subjects.

Copper nutrition and biochemistry and human (patho)physiology

The essential trace mineral copper plays important roles in human physiology and pathophysiology. Disruption of copper homeostasis may underlie the development of ischemic heart disease, and connective tissue and neurodegenerative disorders. Copper also likely participates in the host response to bacterial infection and is further implicated more broadly in regulating immunity. Recent studies further associate copper with disruption of lipid homeostasis, as is frequently seen in, for example, non-alcoholic fatty liver disease (NAFLD). Moreover, continuing investigation of copper chaperones has revealed new roles for these intracellular copper-binding proteins. Despite these (and many other) significant advances, many questions related to copper biology remain unanswered. For example, what are the most sensitive and specific biomarkers of copper status, and which ones are useful in marginal (or "sub-clinical" copper deficiency)? Further research on this topic is required to inform future investigations of copper metabolism in humans (so the copper status of study participants can be fully appreciated). Also, are current recommendations for copper intake adequate? Recent studies suggest that overt copper deficiency is more common than once thought, and further, some have suggested that the copper RDAs for adults may be too low. Additional human balance and interventional studies are necessary and could provide the impetus for reconsidering the copper RDAs in the future. These and myriad other unresolved aspects of copper nutrition will undoubtedly be the focus of future investigation.

Circulating antioxidant vitamins and copper in Azorean coronary artery disease patients under preventive medication - A case study

BACKGROUND AND AIM

Oxidative stress and inflammation are conditions that are deeply involved in atherosclerosis and consequent coronary artery disease (CAD). Therefore, the aim of this study was to assess the relationship among circulating antioxidant vitamins (C, A, E), copper, and other pro- or antioxidant/inflammation markers in patients with and without CAD under preventive medication.

SUBJECTS AND METHODS

174 Azorean subjects symptomatic for CAD (age 56 ± 9y; 68 % men) submitted to coronary angiography were split into 2 groups: one formed by CAD patients (≥50 % stenosis in at least one major coronary vessel) and the other by non-CAD patients (<50 % stenosis). Both groups were age-, sex- and BMI-matched. Plasma levels of vitamins or copper were measured by HPLC and AAS, respectively.

RESULTS AND CONCLUSIONS

Lower vitamin C levels were observed in CAD patients (mainly in women, who exhibited a high rate of diabetes mellitus) as compared to the non-CAD ones. Also, CAD patients (mainly men) exhibited significantly higher concentrations of plasma copper than their non-CAD counterparts (1.17 ± 0.3 mg/L vs. 1.09 ± 0.3 mg/L, p = 0.030). In bivariate analysis, plasma copper levels were positively associated with serum LDL-cholesterol (r=0.22; p = 0.004) and chiefly with C-reactive protein (r=0.40; p < 0.001). Furthermore, they were significantly lower in recurrent vs. non recurrent CAD patients (1.07±0.2 vs. 1.24±0.3 mg/L, p = 0.004). ROC analysis showed that plasma copper, whenever >1.06 mg/L, was an independent risk factor for CAD in primary prevention for men, which suggests that its levels can fluctuate with medical therapy (such as anti-inflammatory), thus indicating that copper is not a reliable marker for CAD. Moreover, plasma copper concentration was not associated with CAD severity. Yet, results do suggest that, even within its reference concentration range, it could be useful as an acute inflammation marker in CAD management.

Reverse regulation of hepatic ceruloplasmin production in rat model of myocardial ischemia

BACKGROUND

Ceruloplasmin (Cp) is a major copper-binding protein produced in the liver and delivers copper to extrahepatic organs. Patients with myocardial infarction are often featured by an elevation of serum copper concentrations due to copper efflux from ischemic hearts. The present study was undertaken to test the hypothesis that serum copper elevation leads to up-regulation of hepatic Cp in myocardial infarction.

METHODS

Adult male Sprague-Dawley rats were subjected to left anterior descending (LAD) coronary artery ligation to induce myocardial infarction. Serum copper and Cp levels, as well as changes in hepatic Cp and copper-transporting P-type ATPase (Atp7b), were determined from blood and liver samples collected on day 1, 4, or 7 after the operation.

RESULTS

Serum copper concentrations were significantly increased on day 4 after LAD ligation, accompanied by an increase in serum Cp levels and activities. Concomitantly, the protein levels of Cp and copper exporter, Atp7b, were also significantly increased in the liver. Furthermore, inhibiting the increase of serum copper by a copper chelator, triethylenetetramine (TETA), effectively abolished the elevated Cp activity after LAD ligation.

CONCLUSION

These results indicate that serum Cp elevation in response to myocardial ischemia most likely resulted from the increased hepatic Cp production, which in turn was more responsive to serum copper elevation than inflammatory response following myocardial ischemia.

Trace element, immune and opioid biomarkers of unstable angina, increased atherogenicity and insulin resistance: Results of machine learning

BACKGROUND

Aberrations in endothelial cells, immune and oxidative pathways are associated with atherosclerosis (ATS) and unstable angina (UA). The role of trace elements, minerals, and the endogenous opioid system (EOS) in UA are less well established.

METHODS

We measured lipid, insulin resistance (IR), and immune, trace element (copper and zinc), mineral (magnesium, calcium), EOS (β-endorphin and mu-opioid receptor (MOR)) and antioxidant (vitamin D3) biomarkers in patients with ATS (n = 60) and UA (n = 60) and healthy controls (n = 58).

RESULTS

ATS patients showed increased atherogenic and IR indices, IL-6, IL-10, β-endorphin, copper and magnesium, and lower zinc than healthy controls. Logistic regression showed that UA was significantly discriminated from ATS without UA with an accuracy of 85.5 % using calcium, IL-10, β-endorphin, MOR, triglycerides, IR (all positively), and copper and vitamin D3 (inversely). Neural networks showed that UA was discriminated from ATS without UA with an area under the ROC curve of 0.942 using MOR, β-endorphin, calcium, insulin resistance, vitamin D3 and copper as input variables. We found that 50.0 % of the variance in IR was explained by the regression on copper, IL-10, IL-6 (all positively), and zinc (inversely), while 32.9 % of the variance in the atherogenic index of plasma was explained by copper, IL-10 (both positively), and magnesium (inversely).

CONCLUSION

UA is not only mediated by insulin resistance, atherogenicity, and immune disorders, but also by aberrations in the endogenous opioid system and trace elements as well as lowered antioxidant levels. Copper appears to play a key role in IR and atherogenicity.

The association between serum copper concentrations and elevated blood pressure in US children and adolescents: National Health and Nutrition Examination Survey 2011-2016

BACKGROUND

Copper is an essential trace metal with potential interest for cardiovascular effects. Few studies have explored the association between copper and blood pressure in children and adolescents.

METHOD

We conducted a cross-sectional analysis of 1242 children and adolescents aged 8-17 years who participated in the 2011 to 2016 National Health and Nutrition Examination Survey. Using 2017 American Academy of Pediatrics guidelines, elevated blood pressure (EBP) was defined as a mean systolic and/or diastolic blood pressure (BP) ≥ 90th percentile for sex, age, and height for children aged 1-12 years and systolic BP ≥ 120 mmHg or diastolic BP ≥ 80 mmHg for adolescent age 13-17 years. Mean serum copper was 114.17 μg/dL.

RESULTS

After multiple adjustments, dose-response analyses revealed that EBP was associated with progressively higher serum copper concentrations in a nonlinear trend. In comparison with the lowest quartile of serum copper concentrations, the adjusted odds of EBP for the highest quartile was 5.26 (95% confidence interval, 2.76-10.03).

CONCLUSION

Our results suggested that high serum copper concentrations were significantly associated with EBP in US children and adolescents.

Anti-Atherosclerotic Activity of (3R)-5-Hydroxymellein from an Endophytic Fungus Neofusicoccum parvum JS-0968 Derived from Vitex rotundifolia through the Inhibition of Lipoproteins Oxidation and Foam Cell Formation

An endophytic fungus, Neofusicoccum parvum JS-0968, was isolated from a plant, Vitex rotundifolia. The chemical investigation of its cultures led to the isolation of a secondary metabolite, (3R)-5-hydroxymellein. It has been reported to have antifungal, antibacterial, and antioxidant activity, but there have been no previous reports on the effects of (3R)-5-hydroxymellein on atherosclerosis. The oxidation of lipoproteins and foam cell formation have been known to be significant in the development of atherosclerosis. Therefore, we investigated the inhibitory effects of (3R)-5-hydroxymellein on atherosclerosis through low-density lipoprotein (LDL) and high-density lipoprotein (HDL) oxidation and macrophage foam cell formation. LDL and HDL oxidation were determined by measuring the production of conjugated dienes and malondialdehyde, the amount of hyperchromicity and carbonyl content, conformational changes, and anti-LDL oxidation. In addition, the inhibition of foam cell formation was measured by Oil red O staining. As a result, (3R)-5-hydroxymellein suppressed the oxidation of LDL and HDL through the inhibition of lipid peroxidation, the decrease of negative charges, the reduction of hyperchromicity and carbonyl contents, and the prevention of apolipoprotein A-I (ApoA-I) aggregation and apoB-100 fragmentation. Furthermore, (3R)-5-hydroxymellein significantly reduced foam cell formation induced by oxidized LDL (oxLDL). Taken together, our data show that (3R)-5-hydroxymellein could be a potential preventive agent for atherosclerosis via obvious anti-LDL and HDL oxidation and the inhibition of foam cell formation.

Association Between the Change of Serum Copper and Ischemic Stroke: a Systematic Review and Meta-Analysis

Ischemic stroke is the most common stroke subtypes with all strokes. More and more studies found that serum copper was related to the ischemic stroke. However, the correlation between serum copper and ischemic stroke was inconsistent. We performed the meta-analysis to assess the association between the change of serum copper and ischemic stroke. Electronic databases were identified to search for relevant studies about serum copper and ischemic stroke from inception to February 28, 2019. Eight studies with a total of 777 participants were included into this meta-analysis. Because of high heterogeneity (I² = 71%), we chose a random effect model. Our results showed the serum copper levels were significantly higher in ischemic stroke group compared with controls group (pooled mean difference, 1.25; 95% confidence intervals (CIs), 0.07-2.43; P = 0.04), in particular studies after the year of 2009 (I² = 0%; pooled mean difference, 2.16; 95% CI, 1.37-2.95; P < 0.00001). Serum copper was associated with ischemic stroke, and it may be one of the risk factors of ischemic stroke.

Anti-Atherosclerotic Effects of Fruits of Vitex rotundifolia and Their Isolated Compounds via Inhibition of Human LDL and HDL Oxidation

Low-density lipoprotein (LDL) and high-density lipoprotein (HDL) oxidation are well known to increase the risk for atherosclerosis. In our ongoing research on natural products with inhibitory activities against oxidation of lipoproteins, fruits of Vitex rotundifolia were found to be highly active. There is no report on the effects on LDL and HDL oxidation. Herein, we investigated the inhibitory effects of V. rotundifolia fruit extract and its six compounds, which are: (1) artemetin, (2) casticin, (3) hesperidin, (4) luteolin, (5) vitexin, and (6) vanillic acid, against LDL and HDL oxidation. The LDL and HDL oxidations were determined by measuring production of conjugated dienes and thiobarbituric acid reactive substances, amount of hyperchromicity and carbonyl content, change in electrical charge, and apoA-I aggregation. In addition, the contents of the compounds in the extracts were analyzed using HPLC-DAD. Consequently, extracts of Vitex rotundifolia fruits and compounds 2 and 4 suppressed oxidation of LDL and HDL, showing inhibition of lipid peroxidation, decrease of negative charges in lipoproteins, reduction of hyperchromicity, decrease in carbonyl contents, and prevention of apoA-I aggregation. In particular, compounds 2 and 4 exhibited more potent inhibitory effect on oxidation of LDL and HDL than the extracts, suggesting their protective role against atherosclerosis via inhibition of LDL and HDL oxidation. The contents of artemetin, casticin, and vanillic acid in the extracts were 1.838 ± 0.007, 8.629 ± 0.078, and 1.717 ± 0.006 mg/g, respectively.

Levels and temporal variations of urinary lead, cadmium, cobalt, and copper exposure in the general population of Taiwan

Toxic metal contamination in food products and the environment is a public health concern. Therefore, understanding human exposure to cadmium (Cd), lead (Pb), cobalt (Co), and copper (Cu) levels in the general population of Taiwan is necessary and urgent. We aimed to establish the human biomonitoring data of urine toxic metals, exposure profile changes, and factors associated with metal levels in the general population of Taiwan. We randomly selected 1601 participants older than 7 years of age (36.9 ± 18.7 years (7-84 years)) from the Nutrition and Health Survey in Taiwan (NAHSIT) conducted during 1993-1996 (93-96) and 2005-2008 (05-08) periods and measured the levels of four metals in the participants' urine samples using inductively coupled plasma-mass spectrometry. The median (range) levels of urinary Cd, Pb, Co, and Cu in participants from the NAHSIT 93-96 (N = 821)/05-08 (N = 780) were 0.60 (ND-13.90)/0.72 (ND-7.44), 2.28 (ND-63.60)/1.09 (0.04-48.88), 0.91 (0.08-17.30)/1.05 (0.05-22.43), and 16.87 (2.62-158.28)/13.66 (1.67-189.70) μg/L, respectively. We found that the urinary median levels of Pb and Cu in our participants were significantly lower in the NAHSIT 05-08 (Pb 1.09 μg/L, Cu 13.66 μg/L) than in the NAHSIT 93-96 (Pb 2.28 μg/L, Cu 16.87 μg/L; P < 0.01), whereas those of Cd and Co were significantly higher in the NAHSIT 05-08 (Cd 0.72 μg/L, Co 1.05 μg/L; P < 0.01). Youths had higher exposure levels of Pb, Co, and Cu than adults. Participants with alcohol consumption, betel quid chewing, or cigarette smoking had significantly higher median levels of urinary Pb or Cu (P < 0.01) than those without. Principal components and cluster analysis revealed that sex had different exposure profiles of metals. We concluded that levels of urinary Cd, Pb, Co, and Cu exposure in the general Taiwanese varied by age, sex, and lifestyles.

Prediction of carotid intima-media thickness in obese patients with low prevalence of comorbidities by serum copper bioavailability

BACKGROUND AND AIM

Western societies, with growing prevalence, suffer from various metabolic diseases like obesity and hepatic steatosis, better defined as non-alcoholic fatty liver disease, or cardiovascular (CV) diseases that are strictly linked to each other. The association of their occurrence with the altered homeostasis of metals is an intriguing issue. Copper in particular was identified as key player in various metabolic derangements. On these bases, we aimed at investigating the possible association of serum copper levels with an indicator of early CV risk as the intima-media thickness (IMT) of carotid artery and its predictive value in a selected population of obese patients.

METHODS

We performed a cross-sectional study recruiting 100 obese patients characterized by a low prevalence of comorbidities. Ultrasound investigation for hepatic steatosis and IMT evaluation were performed. Serum samples were collected and then analyzed through atomic absorption spectrometry to evaluate their copper content. Possible correlations between copper bioavailability and biochemical, clinical, and anthropometric characteristics of patients were sought.

RESULTS

Age negatively predicted copper serum levels of patients (P = 0.009). However, the most interesting finding is the negative prediction of IMT by the copper serum levels (t = -2.23, P = 0.028, least absolute deviations regression). Factor analysis confirmed the aforementioned inverse correlation and highlighted the strong inverse correlation between smoking and copper serum levels.

CONCLUSION

Our data show that an altered copper bioavailability predicts early atherosclerosis as main CV risk in obese patients with hepatic steatosis detected by ultrasound, shedding some light in this pathological scenario.

The Effect of Curcumin on Serum Copper and Zinc and Zn/Cu Ratio in Individuals with Metabolic Syndrome: A Double-Blind Clinical Trial

Metabolic syndrome is a complex disorder with high socioeconomic costs and a high global prevalence. The serum concentrations of some trace elements are higher in people with metabolic syndrome compared to normal individuals. Curcumin is derived from turmeric and has antioxidant and anti-inflammatory properties. Curcumin may therefore have a potential role in the management of cardiovascular risk. The aim of this study was to investigate the effects of curcumin on serum copper (Cu), zinc (Zn), and Zn/Cu ratio levels in patients with metabolic syndrome. A double-blind clinical trial was designed in which 120 individuals with metabolic syndrome were randomly assigned to one of three groups: curcumin 1gr/day, phospholipidated curcumin 1gr/day, or a placebo, each taken for 6 weeks. Serum copper and zinc were measured before and after intervention. At baseline, in addition to obtaining the anthropometric characteristics of participants, a fasting blood sample was taken from each participant, and the concentrations of serum Cu and Zn were measured by atomic absorption (Varian AA 240 FS model). Serum Zn concentrations rose significantly in the phospholipidated curcumin and curcumin groups, being significantly higher (p <.001) in the phospholipidated curcumin group than in the curcumin group (p <.05). Serum Zn concentration fell in the control group (p <.05). Changes in serum Zn level from baseline to the levels after six weeks' intervention were significantly different between the groups, but changes in serum Cu from between baseline until after intervention were not significantly different. The serum Zn/Cu level in phospholipidated curcumin and curcumin groups after intervention was higher than for the control group, but it was more significant in the group taking phospholipidated curcumin (p <.001). Curcumin and phospholipidated curcumin complex, given at a dose of 1 g per day for six weeks, were associated with an increase in serum zinc and consequently zinc-to-copper ratio.

Copper transporters and copper chaperones: roles in cardiovascular physiology and disease

Copper (Cu) is an essential micronutrient but excess Cu is potentially toxic. Its important propensity to cycle between two oxidation states accounts for its frequent presence as a cofactor in many physiological processes through Cu-containing enzymes, including mitochondrial energy production (via cytochrome c-oxidase), protection against oxidative stress (via superoxide dismutase), and extracellular matrix stability (via lysyl oxidase). Since free Cu is potentially toxic, the bioavailability of intracellular Cu is tightly controlled by Cu transporters and Cu chaperones. Recent evidence reveals that these Cu transport systems play an essential role in the physiological responses of cardiovascular cells, including cell growth, migration, angiogenesis and wound repair. In response to growth factors, cytokines, and hypoxia, their expression, subcellular localization, and function are tightly regulated. Cu transport systems and their regulators have also been linked to various cardiovascular pathophysiologies such as hypertension, inflammation, atherosclerosis, diabetes, cardiac hypertrophy, and cardiomyopathy. A greater appreciation of the central importance of Cu transporters and Cu chaperones in cell signaling and gene expression in cardiovascular biology offers the possibility of identifying new therapeutic targets for cardiovascular disease.

Acute copper overload induces vascular dysfunction in aortic rings due to endothelial oxidative stress and increased nitric oxide production

The mechanisms involved in vascular reactivity alterations promoted by copper (Cu) overload were investigated. Thoracic aorta obtained from male Wistar rats were cut into rings and exposed for 1 h to 10 µg/ml Cu. Exposure to Cu decreased the contractile responses of aortic rings to phenylephrine (PHE). Removal of endothelium and subsequent administration of N-nitro-L arginine methyl ester (L-NAME), tetrahydrobiopterin, aminoguanidine, diethyldithiocarbamic acid, catalase, or tetraethylammonium increased contractile responses. Incubation with apocinyn and tiron enhanced the sensitivity to PHE. Data demonstrated that high concentrations of Cu reduced PHE-mediated vascular reactivity which was associated with elevated production of nitric oxide (NO), which was attributed to activation of inducible NO synthase, and elevated levels of hydrogen peroxide probably related to a rise in superoxide dismutase activity and reactive oxygen species generation.

Metabolic syndrome and atherogenic indices in school children: A worrying panorama in Brazil

BACKGROUND

Metabolic Syndrome (MS) is defined as the combination of a cluster of cardiovascular risk factors. The use of cardiovascular indices such as the ratios TC/HDL-c, LDL-c/HDL-c and TG/HDL-c may help in the assessment of cardiovascular risk. Investigation of cardio-metabolic risks in the pre-adolescent stage is essential to characterize possible patterns for MS in the earliest stages of the life avoiding further irreversible consequences.

AIMS

This work aimed to investigate the presence of MS and cardiovascular indices in a group of children aged 6-10 years.

METHODS

We included 150 children from a city in Brazil. Anthropometric (Body Mass Index and Waist Circumference) and biochemical parameters (glycaemia, total cholesterol, LDL-c, HDL-c, and triglycerides) were evaluated in order to identify the presence of MS. Atherogenic Indices were also calculated (TC/HDL-c, LDL-c/HDL-c and TG/HDL-c).

RESULTS

Our results showed that there are high percentages of children with altered values for biochemical and anthropometric parameters and in the atherogenic indices. MS was identified in 17.8% of the children. The main parameters related to alterations in the atherogenic indices were waist circumference, body mass index and the presence of MS.

CONCLUSION

The high prevalence of MS and alterations in the atherogenic indices in schoolchildren is a worrying panorama. We suggest the performance of more studies focusing on identification, intervention and prevention programs in order to reduce the risk factors of this syndrome in childhood and to reduce future cardiovascular deaths.

Small Molecule Copper and Its Relative Metabolites in Serum of Cerebral Ischemic Stroke Patients

BACKGROUND

Copper is a strong pro-oxidant. The most important pro-oxidative form in serum is small molecule copper (SMC), which is copper that is loosely bound to small molecules, such as amino acids and polypeptides. The association between copper and atherosclerotic diseases has been confirmed, but that between SMC and cerebral ischemic stroke (CIS), one of the most principal manifestations and causes of death of atherosclerotic disease, is not yet clear.

METHODS

We recruited 45 CIS patients and 25 age- and gender-matched healthy controls. We detected their serum levels of SMC, total copper, homocysteine (Hcy), and ceruloplasmin (CP), as well as urinary total copper, and analyzed the relationship of SMC with these aforementioned metabolites or compounds in CIS patients.

RESULTS

SMC was 4.2 ± .5 µg/L and 2.1 ± .9 µg/L; total copper in sera was 1345.5 ± 308.2 µg/L and 1180.3 ± 134.0 µg/L; and total copper in urine was 27.6 ± 9.3 µg/L and 18.8 ± 8.1 µg/L in patients and controls, respectively (all P < .05). Serum CP activity in CIS patients was 59.92 ± 12.11 U/L versus 37.76 ± 5.71 U/L in controls (P = .0001). The concentration of SMC was positively correlated with CP activity, Hcy concentration in sera, and urinary total copper.

CONCLUSION

The serum level of SMC and total copper is remarkably elevated, and SMC positively correlates with Hcy, CP activity, and urinary total copper in CIS patients.