Impaired endothelial function assessed by flow-mediated vasodilatation in workers occupationally exposed to lead

Comparative Study of Elemental Concentrations in the Scalp Hair and Nails of Myocardial Infarction Patients Versus Controls from Pakistan

Ischemia heart disease has become a ubiquitous cause of morbidity and a leading contributor to mortality worldwide. The present study was aimed to quantify the elemental levels for Ca, Cd, Cr, Cu, Fe, K, Mg, Mn, Na, Pb, Sr, and Zn in the scalp hair and nails of myocardial infarction (MI) patients and counterpart controls by flame atomic absorption spectrophotometry. The effects of elemental imbalances on the development of atherosclerosis were evaluated. Average concentrations of Pb (14.7 μg/g), Sr (21.6 μg/g), and Cr (3.70 μg/g) were significantly higher in the scalp hair of the patients, while those of Na, K, Mg, Fe, Mn, and Cd were measured at almost comparable levels in the scalp hair of the patients and controls. In the case of nail samples, average concentrations of Na (1260 μg/g), K (873 μg/g), Sr (70.9 μg/g), Cu (16.6 μg/g), and Mn (16.9 μg/g) were significantly higher in the patients than controls. The correlation study revealed significantly divergent mutual variations among the elements in MI patients and controls. Principal component analysis also manifested the diverse apportionment of the elements in both donor groups. Most of the elements revealed significant disparities in their concentrations based on gender, abode, and smoking habits of the donors in both groups. In conclusion, the elemental imbalance has potential proatherogenic effect that would have a significant impact on sensitive population groups.

Metabonomic analysis of serum of workers occupationally exposed to arsenic, cadmium and lead for biomarker research: a preliminary study

Environmental metabonomics is the application of metabonomics to characterize the interactions of organisms with their environment. Metabolic profiling is an exciting addition to the armory of the epidemiologist for the discovery of new disease risk biomarkers and diagnostics. This work is a continuation of research searching for preclinical serum markers in a group of 389 healthy smelter workers exposed to lead, cadmium and arsenic. Changes in the metabolic profiles were studied using Proton Nuclear Magnetic Resonance Spectroscopy on pooled serum samples from both the metal exposed and control groups. These multivariate metabonomic datasets were analyzed with Principal Component Analysis and Partial Least Squares Discriminant Analysis. Analysis of metabolic profiles of people exposed to heavy metals suggests energy metabolism disturbance induced by heavy metals. Changes in lipid fraction (very-low-density lipoprotein - VLDL, low-density lipoprotein - LDL), unsaturated lipids and in the level of amino acids suggest perturbation of the metabolism of lipids and amino acids. This study illustrated the high reliability of NMR-based metabonomic profiling on the study of the biochemical effects induced by the mixture of heavy metals. This approach is capable of identifying intermediate biomarkers of response to toxicants at environmental/occupational concentrations, paving the way to its use in a monitoring of smelter workers exposed to low doses of lead, cadmium and arsenic.

Assessment of cardiovascular risk in workers occupationally exposed to lead without clinical presentation of cardiac involvement

PURPOSE

The objective of this study was to assess, with aid of SCORE system, of 10-year risk of fatal cardiovascular incidents among workers occupationally exposed to lead, without circulatory system disorders.

METHODS

The studies included 83 men (mean age: 55.14±4.62 years): the 1st group consisted of persons occupationally exposed to lead (group I, n=40), and 2nd group - persons not exposed to lead (group II, n=43). 10-Year risk of fatal cardiovascular incidents was assessed with application of SCORE risk chart designed for Polish population.

RESULTS

In the first group, mean values of SCORE calculated on the basis of the chart including total cholesterol concentration in serum were significantly higher. Also, there were significantly higher: mean values of SCORE calculated on the basis of the chart including total cholesterol to HDL cholesterol ratio, mean values of relative SCORE, percentage of individuals with risk estimated as increased, percentage of individuals with risk estimated as significantly increased. Simultaneously, the significantly lower percentage of individuals with risk estimated as small or moderate was found in the occupationally exposed subjects.

CONCLUSIONS

Persons occupationally exposed to lead compounds are burdened with significantly higher 10-year risk of fatal cardiovascular incident than individuals from the same population not exposed to lead.

Environmental and occupational exposure to lead as a potential risk factor for cardiovascular disease

We have evaluated current knowledge on relations between environmental and occupational exposure to lead with a strong emphasis on cardiovascular disease risk factors, such as the influence of lead compounds on lipid disturbances and arterial blood pressure. In addition, "novel" biochemical and vascular risk factors for cardiovascular diseases were discussed, as well as the combination of lead exposure and genetic predisposition to cardiovascular diseases. Occupationally and educationally, awareness of the unfavourable effects of lead on cardiovascular diseases risk factors should be emphasised. Indeed, accurate identification of the various mechanisms that might account for the effects of lead on the cardiovascular system should be of the highest priority in this field of research.

Electrocardiographic changes in workers occupationally exposed to lead

BACKGROUND

The significance of heavy metals in pathogenesis of the circulatory system diseases remains unresolved. The aim of the study was to evaluate electrocardiographic changes in workers occupationally exposed to lead without clinical presentation of cardiac involvement.

METHODS

A group of 60 smelters and refiners and 45 healthy men, as a control group, were enrolled. Twelve-lead electrocardiogram (ECG) and 24-hour Holter monitoring were performed. Further analysis included heart rate variability (HRV) in time and frequency domains and heart rate turbulence (HRT).

RESULTS

Analysis of 12-lead ECG recordings revealed various pathologies in 27 out of 60 men occupationally exposed to lead. Twenty-four-hour ECG Holter monitoring showed the higher mean heart rate in copper smelters than in healthy subjects (85.8 ± 14.1 bpm vs 72.6 ± 9.2 bpm; P < 0.05) and more premature supraventricular and ventricular contractions (298 ± 235 vs 27 ± 45; P < 0.05 and 152 ± 138 vs 18 ± 18; P < 0.05, respectively). The majority of time domain and frequency domain HRV parameters were significantly lower, and the LF:HF ratio was higher when compared with the control group. Turbulence onset was abnormal in six copper smelters and turbulence slope in five men exposed to lead.

CONCLUSIONS

Electrocardiographic evaluation showed that various heart rhythm disorders were more frequent in metallurgists, as compared to the control group, and the decreased HRV and abnormal parameters of HRT were observed. Noninvasive electrocardiographic evaluation could be a valuable method of the early prediction of cardiovascular disorders in men occupationally exposed to lead.

Proteomic analysis of serum of workers occupationally exposed to arsenic, cadmium, and lead for biomarker research: a preliminary study

The main factor of environmental contamination is the presence of the heavy metals lead, cadmium, and arsenic. The aim of serum protein profile analysis of people chronically exposed to heavy metals is to find protein markers of early pathological changes. The study was conducted in a group of 389 healthy men working in copper foundry and 45 age-matched non-exposed healthy men. Toxicological test samples included whole blood, serum, and urine. Thirty-seven clinical parameters were measured. Based on the parameters values of the healthy volunteers, the centroid in 37-dimensional space was calculated. The individuals in the metal-exposed and control groups were ordered based on the Euclidean distance from the centroid defined by the first component according to Principal Component Analysis (PCA). Serum samples of two individuals, one from the control and one from the metal-exposed group, were chosen for proteomic analysis. In optimized conditions of two-dimensional gel electrophoresis (2-DE), two protein maps were obtained representing both groups. Twenty-eight corresponding protein spots from both protein maps were chosen and identified based on PDQuest analysis and the SWISS-2DPAGE database. From a panel of six proteins with differences in expression greater than a factor of two, three potential markers with the highest differences were selected: hemoglobin-spot 26 (pI 7.05, Mw 10.53), unidentified protein-spot 27 (pI 6.73, Mw 10.17), and unidentified protein-spot 25 (pI 5.75, Mw 12.07). Further studies are required to prove so far obtained results. Identified proteins could serve as potential markers of preclinical changes and could be in the future included in biomonitoring of people exposed to heavy metals.