Comparative Distribution, Correlation, and Chemometric Analyses of Selected Metals in Scalp Hair of Angina Patients and Healthy Subjects

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.

Serum Zinc Ion Concentration Associated with Coronary Heart Disease: A Systematic Review and Meta-Analysis

Aim

Coronary heart disease is a major cause of mortality in developed and developing countries. Changes in the trace element concentration in the human body are one of the main reasons for the transition of the human body from a healthy to a diseased state. In this meta-analysis, we have studied the relationship between the reduction in serum zinc ion concentration and coronary heart disease.

Methods

We used PubMed and Cochrane (as of June 30, 2021) databases for the literature search. Per the requirements of this systematic review, case-control studies involving serum zinc ion concentration and coronary heart disease were searched, and the quality of the included studies was evaluated before the meta-analysis.

Results

A total of 3,981 cases were found across seven articles. The standard mean deviation (SMD) of serum zinc ion concentration was −0.22 [−0.28, −0.15], z = 6.52, and P < 0.05 indicated that the difference was statistically significant. The forest plot results show that I² = 34% < 50%, and the Q test showed P=0.17 > 0.1. These results suggest a lack of heterogeneity among the selected articles. Results from the funnel chart indicated that this study was free from publication bias.

Conclusion

The results of this meta-analysis reveal that a decrease in serum zinc ion concentration is related to the occurrence of coronary heart disease. Clinically, monitoring the serum zinc ion levels is proven to be of great significance for patients with coronary heart disease.

Investigation on the Association of Copper and Copper-to-Zinc-Ratio in Hair with Acute Coronary Syndrome Occurrence and Its Risk Factors

The prevalence of coronary artery disease (CAD) increases every year; however, the impact of microelements on its underlying cause—atherosclerosis—is still unclear. Copper plays numerous regulatory roles in cardiovascular health and was suggested to influence the classic risk factors for CAD. The copper-to-zinc-ratio (Cu/Zn-ratio) reflects systemic oxidative stress–one of the factors in the complex pathogenesis of atherosclerosis. Hair incorporates metal ions during its growth; thus, it reflects the metal exposure that occurred over the last 4–8 weeks. The aim of the presented study was to verify the association between Cu and Cu/Zn-ratio content and the occurrence of acute coronary syndrome (ACS) in the hair of 133 patients who underwent coronary angiography due to suspected ACS. Additionally, association between Cu and Cu/Zn-ratio and selected risk factors for CAD was analyzed. Neither Cu nor Cu/Zn-ratio levels were associated with the occurrence of ACS, regardless of its type (UA/NSTEMI/STEMI). We did not find a significant association between Cu content in hair and risk factors for CAD. The Cu/Zn-ratio in hair was significantly correlated only with body mass index. The relationship of Cu content and Cu/Zn-ratio in hair with CAD, its risk factors and ACS appears to be complex and requires further well-designed research.

Reduced Serum Zinc Ion Concentration Is Associated with Coronary Heart Disease

Imbalances in trace element concentrations in the blood as a result of poor nutrition may affect the development of coronary heart disease. To study the relationship between zinc ion concentration in the peripheral blood and coronary heart disease, we performed multiple logistic regression and hierarchical analyses on blood measurements of 3541 patients. The experimental group comprised 1253 patients diagnosed with coronary heart disease, and the control group included 2288 healthy patients. The zinc ion concentrations were measured by a color rendering method, and the results were analyzed using SPSS software. Fifteen laboratory quality evaluation samples from the Clinical Laboratory Center of the Chinese Ministry of Health were selected for analysis. The mean values and average bias were calculated. The estimated qualified judgment standard was < 1/2 TEa (the allowable total error for zinc). A hierarchical analysis of risk factors, including smoking, age, sex, and menopause in women, was performed. The results revealed that non-smoking, aging (especially postmenopausal women), and low blood zinc concentrations were independent risk factors for the development of coronary heart disease (P ≤ 0.05, zinc ion concentration less than 13.82 ± 2.91). The findings strongly suggest that decreased zinc ion concentrations in the peripheral blood can be used as an independent risk factor for the prediction of coronary heart disease, especially in older patients, non-smokers, and women, in particular, postmenopausal women.

Chemometric Evaluation of Elemental Imbalances in the Scalp Hair of Valvular Heart Disease Patients in Comparison with Healthy Donors

The present study deals with the plausible association between the trace elemental imbalances and the emergence of valvular heart disease (VHD). A total of 14 elements including Ca, Cd, Co, Cr, Cu, Fe, K, Li, Mg, Mn, Na, Pb, Sr and Zn in the scalp hair of VHD patients and healthy donors were analysed by flame atomic absorption spectrophometry employing wet acid digestion methodology. Median levels of Cu, Fe, Mg, Mn and Sr in the scalp hair of patients were significantly higher compared to those of the healthy donors, while the median concentrations of K and Na were found to be considerably higher in the scalp hair of the healthy donors. In addition, substantially elevated Cu/Zn value in patients indicated the prevalence of inflammatory processes inside the body. The correlation coefficients among the elements in the hair of VHD patients were significantly diverse compared to those of the healthy donors. Multivariate statistical methods showed noticeably dissimilar apportionment of the elements in the two groups. Variations in the elemental levels were also observed with gender, habitat, dietary/smoking habits and occupations of both donor groups. Overall, the study revealed significant imbalances among the essential and toxic elements in the scalp hair of VHD patients compared to those of the healthy subjects.

Statistical evaluation of essential/toxic metal levels in the blood of valvular heart disease patients in comparison with controls

The present study was designed to investigate the role of selected essential and toxic metals in the onset/prognosis of valvular heart disease (VHD). Nitric acid-perchloric acid based wet digestion procedure was used for the quantification of the metals by flame atomic absorption spectrophotometry. Comparative appraisal of the data revealed that average levels of Cd, Co, Cr, Fe, K, Li, Mn and Zn were significantly higher in blood of VHD patients, while the average concentration of Ca was found at elevated level in controls (P < 0.05). However, Cu, Mg, Na, Sr and Pb depicted almost comparable levels in the blood of both donor groups. The correlation study revealed significantly different mutual associations among the metals in the blood of VHD patients compared with the controls. Multivariate statistical methods showed substantially divergent grouping of the metals for the patients and controls. Some significant differences in the metal concentrations were also observed with gender, abode, dietary/smoking habits and occupations of both donor groups. Overall, the study demonstrated that disproportions in the concentrations of essential/toxic metals in the blood are involved in pathogenesis of the disease.