Relationship between lead absorption and iron status and its association with oxidative stress markers in lead-exposed workers

Background: The emission of lead (Pb) occurring during the extraction, processing and industrial applications of this element remains a significant environmental risk factor. The absorbability of lead in humans is strongly associated with the general health status of exposed individuals. Existing mineral deficiencies are considered being a predisposition to an increased Pb uptake. Both, iron deficiency and lead poisoning are the major caus-ative factors responsible for the prevalence of anemia within the vulnerable population, especially in children. Although some of the intervention programs of counteracting lead poisoning by iron supplementation proved to be effective in the Pb-exposed population, the exact mechanisms of this interaction still require further studies. The objective of the presented study was to examine the association of iron level on oxidative stress measures and its effects on the severity of lead toxicity in the exposed population. Methods: The analyzed population consisted of 270 male workers from the lead-zinc smelter. The studied pop-ulation was divided into two sub-groups based on the serum iron concentration: low iron level group (L-Fe; Fe median value). Measured traits comprised of blood lead (PbB), serum Fe and zinc protoporphyrin (ZPP) levels as well as a blood count and oxidative stress markers. Results: No significant correlation between serum iron concentration and PbB in the tested cohort was found. On the contrary, the analysis of ZPP levels (long-term marker related to a hematologic toxic effect of Pb) within the subgroups differing in serum Fe level shown that ZPP was 12.3 % lower (p =0.043) in subjects classified within the H-Fe group. A positive correlation of serum Fe and total antioxidant capacity (TAC) was found (R =0.1999). The conducted 3-D PCA analysis showed that individuals classified within the H-Fe group were characterized by the co-occurrence of higher Fe levels, lower ZPP, and higher TAC value. Conclusion: These results support the existing evidence providing that maintaining the optimal status of Fe may play a significant role in preventing the lead poisoning and alleviating harmful effects of Pb on the oxidative balance in humans

THE EFFECT OF OCCUPATIONAL EXPOSURE TO LEAD ON THE NON-ENZYMATIC ANTIOXIDANT SYSTEM

Background: The role of non-enzymatic antioxidants, such as uric acid, albumin, bilirubin, and α-tocopherol, in lead poisoning remains unclear. Therefore, the aim of the study was to explore the association between occupational exposure to lead and nonenzymatic antioxidant concentrations in serum and plasma. Material and Methods: The study population consisted of 278 healthy male employees of lead-zinc plants, with 129 workers classified as having low lead exposure (blood lead level – PbB = 20–39.9 μg/dl) and 149 workers classified as having high lead exposure (PbB = 40–59.8 μg/dl). The control group was composed of 73 healthy male administrative workers. No one from this group had blood lead level or zinc protoporphyrin (ZPP) level greater than normal levels, being 10 μg/dl and 2.5 μg/g of hemoglobin, respectively. In addition to the levels of PbB and ZPP, serum levels of uric acid (UA), albumin, thiol groups of albumin, and bilirubin were determined. The ferric reducing ability of plasma (FRAP) and the plasma level of α-tocopherol were also evaluated. Results: Lead exposure indices were significantly elevated in the examined subgroups as compared with the controls. Serum uric acid levels were significantly elevated in both subgroups, particularly in the group with high exposure. Serum bilirubin concentration was significantly elevated in the group with high exposure compared with the control group, while in the group with low exposure, it showed only a non-significant trend towards an increase. In contrast, ferric-reducing ability of plasma was not significantly greater in the examined subgroups as compared with the control group. Nevertheless, levels of albumin, thiol groups of albumin, and α-tocopherol levels were significantly decreased in the exposed subgroups compared with the control group. Conclusions: Occupational exposure to lead interferes with the blood non-enzymatic antioxidant system. Med Pr 2014;65(4):443–45

Perinatal Manganese Exposure and Hydroxyl Radical Formation in Rat Brain

The present study was designed to investigate the role of pre- and postnatal manganese (Mn) exposure on hydroxyl radical (HO•) formation in the brains of dopamine (DA) partially denervated rats (Parkinsonian rats). Wistar rats were given tap water containing 10,000 ppm manganese chloride during the duration of pregnancy and until the time of weaning. Control rat dams consumed tap water without added Mn. Three days after birth, rats of both groups were treated with 6-hydroxydopamine at one of three doses (15, 30, or 67 µg, intraventricular on each side), or saline vehicle. We found that Mn content in the brain, kidney, liver, and bone was significantly elevated in dams exposed to Mn during pregnancy. In neonates, the major organs that accumulated Mn were the femoral bone and liver. However, Mn was not elevated in tissues in adulthood. To determine the possible effect on generation of the reactive species, HO• in Mn-induced neurotoxicity, we analyzed the contents of 2.3- and 2.5-dihydroxybenzoic acid (spin trap products of salicylate; HO• being an index of in vivo HO• generation), as well as antioxidant enzyme activities of superoxide dismutase (SOD) isoenzymes and glutathione S-transferase (GST). 6-OHDA-depletion of DA produced enhanced HO• formation in the brain tissue of newborn and adulthood rats that had been exposed to Mn, and the latter effect did not depend on the extent of DA denervation. Additionally, the extraneuronal, microdialysate, content of HO• in neostriatum was likewise elevated in 6-OHDA-lesioned rats. Interestingly, there was no difference in extraneuronal HO• formation in the neostriatum of Mn-exposed versus control rats. In summary, findings in this study indicate that Mn crosses the placenta but in contrast to other heavy metals, Mn is not deposited long term in tissues. Also, damage to the dopaminergic system acts as a “trigger mechanism,” initiating a cascade of adverse events leading to a protracted increase in HO• generation, and the effects of Mn and 6-OHDA are compounded. Moreover, HO• generation parallels the suppression of SOD isoenzymes and GST in the brains of rats lesioned with 6-OHDA and/or intoxicated with Mn—the most prominent impairments being in frontal cortex, striatum, and brain stem. In conclusion, ontogenetic Mn exposure, resulting in reactive oxygen species, HO• formation, represents a risk factor for dopaminergic neurotoxicity and development of neurodegenerative disorders

Serum antinuclear autoantibodies are associated with measures of oxidative stress and lifestyle factors:analysis of LIPIDOGRAM2015 and LIPIDOGEN2015 studies

Introduction: Oxidative stress is one of many factors suspected to promote antinuclear autoantibody (ANA) formation. Reactive oxygen species can induce changes in the antigenic structure of macromolecules, causing the immune system to treat them as “neo-antigens” and start production of autoantibodies. This study was designed to evaluate the relationship between oxidative stress markers, lifestyle factors and the detection of ANA. Material and methods: We examined measures of oxidative stress indices of free-radical damage to lipids and proteins, such as total oxidant status (TOS), concentration of protein thiol groups (PSH), and malondialdehyde (MDA), activity of superoxide dismutase (SOD) in 1731 serum samples. The parameters of the non-enzymatic antioxidant system, such as total antioxidant status (TAS) and uric acid (UA) concentration, were also measured and the oxidative stress index (OSI-index) was calculated. All samples were tested for the presence of ANA using an indirect immunofluorescence assay (IIFA). Results: The presence of ANA in women was associated with lower physical activity (p = 0.036), less frequent smoking (p = 0.007) and drinking of alcohol (p = 0.024) accompanied by significant changes in SOD isoenzymes activity (p &lt; 0.001) and a higher uric acid (UA) concentration (p &lt; 0.001). In ANA positive males we observed lower concentrations of PSH (p = 0.046) and increased concentrations of MDA (p = 0.047). Conclusions: The results indicate that local oxidative stress may be associated with increased probability of ANA formation in a sex-specific manner.</p

Relationship Between Anti-DFS70 Autoantibodies and Oxidative Stress

Background: The anti-DFS70 autoantibodies are one of the most commonly and widely described agent of unknown clinical significance, frequently detected in healthy individuals. It is not known whether the DFS70 autoantibodies are protective or pathogenic. One of the factors suspected of inducing the formation of anti-DFS70 antibodies is increased oxidative stress. We evaluated the coexistence of anti-DFS70 antibodies with selected markers of oxidative stress and investigated whether these antibodies could be considered as indirect markers of oxidative stress.Methods: The intensity of oxidative stress was measured in all samples via indices of free-radical damage to lipids and proteins such as total oxidant status (TOS), concentrations of lipid hydroperoxides (LPH), lipofuscin (LPS), and malondialdehyde (MDA). The parameters of the non-enzymatic antioxidant system, such as total antioxidant status (TAS) and uric acid concentration (UA), were also measured, as well as the activity of superoxide dismutase (SOD). Based on TOS and TAS values, the oxidative stress index (OSI) was calculated. All samples were also tested with indirect immunofluorescence assay (IFA) and 357 samples were selected for direct monospecific anti DFS70 enzyme-linked immunosorbent assay (ELISA) testing.Results: The anti-DFS70 antibodies were confirmed by ELISA test in 21.29% of samples. Compared with anti-DFS70 negative samples we observed 23% lower concentration of LPH (P = .038) and 11% lower concentration of UA (P = .005). TOS was 20% lower (P = .014). The activity of SOD was up to 5% higher (P = .037). The Pearson correlation showed weak negative correlation for LPH, UA, and TOS and a weak positive correlation for SOD activity.Conclusion: In samples positive for the anti-DFS70 antibody a decreased level of oxidative stress was observed, especially in the case of samples with a high antibody titer. Anti-DFS70 antibodies can be considered as an indirect marker of reduced oxidative stress or a marker indicating the recent intensification of antioxidant processes.</p

Analysis of the impact of sex and age on the variation in the prevalence of antinuclear autoantibodies in Polish population : a nationwide observational, cross-sectional study

The detection of antinuclear autoantibody (ANA) is dependent on many factors and varies between the populations. The aim of the study was first to assess the prevalence of ANA in the Polish adult population depending on age, sex and the cutoff threshold used for the results obtained. Second, we estimated the occurrence of individual types of ANA-staining patterns. We tested 1731 patient samples using commercially available IIFA using two cutoff thresholds of 1:100 and 1:160. We found ANA in 260 participants (15.0%), but the percentage of positive results strongly depended on the cutoff level. For a cutoff threshold 1:100, the positive population was 19.5% and for the 1:160 cutoff threshold, it was 11.7%. The most prevalent ANA-staining pattern was AC-2 Dense Fine speckled (50%), followed by AC-21 Reticular/AMA (14.38%) ANA more common in women (72%); 64% of ANA-positive patients were over 50 years of age. ANA prevalence in the Polish population is at a level observed in other highly developed countries and is more prevalent in women and elderly individuals. To reduce the number of positive results released, we suggest that Polish laboratories should set 1:160 as the cutoff threshold. © 2021, The Author(s). **Please note that there are multiple authors for this article therefore only the name of the first 30 including Federation University Australia affiliate “Fadi Charchar" is provided in this record*

Serum antinuclear autoantibodies are associated with measures of oxidative stress and lifestyle factors - analysis of LIPIDOGRAM2015 and LIPIDOGEN2015 studies

Introduction: Oxidative stress is one of many factors suspected to promote antinuclear autoantibody (ANA) formation. Reactive oxygen species can induce changes in the antigenic structure of macromolecules, causing the immune system to treat them as “neo-antigens” and start production of autoantibodies. This study was designed to evaluate the relationship between oxidative stress markers, lifestyle factors and the detection of ANA. Material and methods: We examined measures of oxidative stress indices of free-radical damage to lipids and proteins, such as total oxidant status (TOS), concentration of protein thiol groups (PSH), and malondialdehyde (MDA), activity of superoxide dismutase (SOD) in in 1731 serum samples. The parameters of the non-enzymatic antioxidant system, such as total antioxidant status (TAS) and uric acid concentration (UA), were also measured and the oxidative stress index (OSI -index) was calculated. All samples were tested for the presence of ANA using an indirect immunofluorescence assay (IIFA). Results: The presence of ANA in women was associated with lower physical activity (p=0.036), less frequent smoking (p=0.007) and drinking of alcohol (p=0.024) accompanied by significant changes in SOD isoenzymes activity (p&lt;0.001) and a higher uric acid (UA) concentration (p&lt;0.001). In ANA positive males we observed lower concentrations of PSH (p=0.046) and increased concentrations of MDA (p=0.047). Conclusions: The results indicate that local oxidative stress may be associated with increased probability of ANA formation in a sex-specific manner

The prevalence of cardiovascular risk factors and cardiovascular disease among primary care patients in Poland:results from the LIPIDOGRAM2015 study

BACKGROUND AND AIM: To estimate the prevalence of cardiovascular (CV) disease and CV risk factors among Polish patients. METHODS: A nationwide cross-sectional study, LIPIDOGRAM2015, was carried out in Poland in the 4th quarter of 2015 and 1st and 2nd quarters of 2016; 438 primary care physicians enrolled 13,724 adult patients that sought medical care in primary health care practices. RESULTS: Nearly 19% of men and approximately 12% of women had cardiovascular disease (CVD). Over 60% of the recruited patients had hypertension (HTN), >80% had dyslipidaemia and <15% of patients were diagnosed with diabetes (DM). All of these disorders were more frequent in men. In 80% of patients the waist circumference exceed norm for the European population. Less than half of the patients were current smokers or had smoked in the past. Patients with CVD had significantly higher blood pressure and glucose levels but lower low density lipoprotein-cholesterol level. CONCLUSIONS: The prevalence of CVD and CV risk factors among patients in Poland is high. CVD is more common in men than in women. The most common CV risk factors are excess waist circumference, dyslipidaemia and HTN. Family physicians should conduct activities to prevent, diagnose early and treat CVD in the primary health care population

Lead-elevated activity of xanthine oxidase in lead-exposed workers

Background: The aim of the present study was to explore the connection between lead toxicity and the activity of xanthine oxidase (XO). In addition, we indicated the uric acid (UA) and creatinine levels and concentration of erythrocyte malondialdehyde (MDA) to estimate oxidative stress intensity. Materials and Methods: The examined group consisted of 125 healthy male employees of zinc and lead works. The examined group was divided into tertiles according to blood lead levels. In the collected blood samples, concentrations of lead-exposure indices, UA, creatinine, and MDA as well as activity of XO were measured concomitantly. The control group consisted of 32 healthy male administrative workers who were exposed to lead only environmentally. Results: XO activity and MDA level were significantly elevated in all tertiles compared to the control group. Creatinine level was significantly elevated in the medium and high tertiles. However, the level of UA was significantly elevated in the high tertile, while in the low and medium tertile only a tendency toward higher values was observed. Conclusions: Occupational exposure to lead induces activity of XO. This induction may contribute to the observed simultaneously increased oxidative stress, measured as MDA level, and the increased level of UA. Med Pr 2013;64(2):175–18

The influence of β-carotene on homocysteine level and oxidative stress in lead-exposed workers

Background: Oxidative stress is involved in lead toxicity. This suggests that some antioxidants may play a role in the treatment of lead poisoning. In the light of this, the aim of the study was to determine whether β-carotene administration reduces oxidative stress and homocysteine level in workers chronically exposed to lead. Material and Methods: The exposed population included healthy male workers exposed to lead who were randomly divided into 2 groups (mean blood lead level ca. 44 μg/dl). Workers in the 1st group (N = 49, reference group) had no antioxidants, drugs, vitamins or dietary supplements administered, while workers in the 2nd group (N = 33) had β-carotene administered in a dose of 10 mg per day for 12 weeks. Biochemical analysis included markers of lead-exposure and the level of malondialdehyde (MDA), an oxidative stress biomarker. We also measured the level of homocysteine (Hcy) and thiol groups as well as the activity of superoxide dismutase (SOD) and its isoenzyme EC-SOD in serum. Results: After supplementation, the level of MDA significantly decreased, compared to baseline, by 16%, and to the reference group. When compared to the reference group, Hcy level was also significantly decreased. However, the level of thiol groups was significantly higher after supplementation with β-carotene compared to the reference group. Analogically, the activity of SOD and EC-SOD was significantly higher compared to the baseline and to the reference group. Conclusions: Despite some controversies over antioxidant properties of β-carotene, our results indicate that its antioxidant action could provide some beneficial effects in lead poisoning independent of chelation. Med Pr 2014;65(3):309–31