Blood pressure in relation to biomarkers of lead, cadmium, copper, zinc, and selenium in men without occupational exposure to metals

Serum Copper Concentrations, Effect Modifiers and Blood Pressure: Insights from NHANES 2011-2014

(1) Background: Epidemiological studies on the relationship between serum copper and hypertension are contradictory. We assessed the relationship between serum copper and blood pressure among adults in the United States. (2) Methods: We divided hypertension into two categories: treated hypertension and untreated hypertension. Linear or logistic regression analysis was applied to investigate the association between serum copper concentrations and blood pressure levels. (3) Results: As compared to quartile 1, the odds ratios (ORs) for untreated hypertension in quartiles 2, 3, and 4 were 1.02 (0.74-1.42), 1.23 (0.88-1.72), and 1.08 (0.74-1.58), respectively, in multivariable analysis (all p > 0.05). In non-hypertension, as compared with quartile 1, the β (95% CI) of systolic blood pressure for quartiles 2, 3, and 4 was -0.92 (-2.07-0.23), -0.05 (-1.30-1.20), and -0.48 (-1.83-0.88), respectively, in multivariable analysis (all p > 0.05). As compared to quartile 1, the ORs for treated hypertension in quartiles 2, 3, and 4 were 1.36 (0.88-2.10), 1.35 (0.87-2.09), and 1.56 (0.98-2.47), respectively, upon multivariable analysis including antihypertensive medication use as a covariate (all p > 0.05). Furthermore, 1SD increase in serum copper was non-significantly associated with 1.16 (0.97-1.37)-fold increased risk of hypertension in multivariable analysis (p = 0.096). (4) Conclusion: In the present study, we discovered that the serum copper concentration was not related with hypertension or blood pressure levels. Antihypertensive drug use may distort the correlation between copper and blood pressure levels. Information on antihypertensive drug use may be taken into account when identifying new risk factors for hypertension.

The association between environmental cadmium exposure, blood pressure, and hypertension: a systematic review and meta-analysis

We performed a systematic and meta-analysis study to find the association between cadmium (Cd) exposure and blood pressure (BP)/hypertension (HTN) in exposed general populations. We searched main databases for literature published between year 2000 and April 15, 2021. Quality assessment was performed with the Joanna Briggs Institute (JBI) critical appraisal tools. Heterogeneity between studies was determined by I-squared (I²) statistic. The random effects model was used to determine the association between blood and urine Cd levels with hypertension. The overall standard differences in mean for Cd level in hypertensive and control groups were 3.34, 1.79, and 8.09 based on samples from blood, urine, and hair, respectively. The overall standard differences in mean for Cd level in the low and high exposure groups were - 0.795 and - 1.036 based on blood and urinary samples, respectively. Our findings indicate a positive relationship between blood and hair Cd levels and hypertension. We also found that hair is the optimal biological sample to find the relationship between Cd exposure and hypertension for both genders. However, more studies are needed to confirm these findings.

Environmental exposure to metals and the risk of high blood pressure: a cross-sectional study from NHANES 2015-2016

Exposure to metal pollution can be caused from inhalation, ingestion, or absorption from air, water, or food. Chronic exposure to trace amounts of metals can lead to high blood pressure, or hypertension, and other chronic diseases. The rationale of our study was to determine if there was a correlation between nineteen forms of urinary metal concentrations and high blood pressure, defined as ≥ 130 mm Hg systolic or ≥ 80 mm Hg diastolic, in the adult US population, to understand the possible impacts of metal exposure on humans. Five types of urinary arsenic species and fourteen types of urinary metals were studied to examine their correlation with high blood pressure. We used the dataset from the 2015-2016 National Health and Nutrition Examination Survey (NHANES) for the study. A specialized complex survey design analysis package was used in analyzing the NHANES data. We used pairwise t tests and the logit regression models to study the correlation between urinary arsenic (five types) and urinary metal (fourteen types) concentrations and high blood pressure. The total study population analyzed included 4037 adults aged 20 years and older, of whom 57.9% of males and 51.7% of females had high blood pressure. Urinary arsenous acid (OR: 2.053, 95% CI: 1.045, 4.035), tin (OR: 1.983, 95% CI: 1.169, 3.364), and cesium (OR: 2.176, 95% CI: 1.013, 4.675) were associated with increased odds of high blood pressure. The other four types of urinary arsenic and twelve types of urinary metals were not associated with high blood pressure. Our results determined that exposure to environmental metals such as arsenous acid, tin, and cesium can be associated with high blood pressure. Further investigation is suggested to support our findings.

Urinary metal/metalloid levels in relation to hypertension among occupationally exposed workers

Occupational exposure to metals can have an adverse effect on the cardiovascular system. However, epidemiological studies of the associations of metals expose with hypertension among occupationally exposed workers were limited. The aim of this study was to investigate the potential association between urinary metal levels and the risk of hypertension among molybdenum miners and iron and steel foundry workers. The cross-sectional study had 395 participants. Urinary metal levels were determined by inductively coupled plasma mass spectrometry. Log-binomial regression model and two-piece-wise regression model were applied to assess the dose-response relationship between metal exposure and hypertension. We observed that increased prevalence ratios for hypertension among the quartile of urinary concentrations of molybdenum, arsenic and lead were positive (all P for trend <0.05). Compared with the lowest quartiles, participants in the highest quartiles of molybdenum, arsenic and lead had a 2.58-fold, 4.30-fold and 4.85-fold increased probability of having hypertension, respectively. In the threshold effect analyses, we found the relationship was nonlinear between urinary molybdenum, cobalt, cadmium, arsenic and lead concentrations and the prevalence of hypertension. In addition, Pb, Mo, As and Co may have joint effect, and a strong positive correlation with the prevalence of hypertension. Conversely, the association between the joint effect of Cd, Pb and Mo versus the prevalence of hypertension is not significant. We provide reference levels of molybdenum, cobalt, cadmium, arsenic and lead that can be used to assess the effects of occupational metal exposure on hypertension.

Associations of environmental exposure to metals with the risk of hypertension in China

Hypertension contributes largely to the global burden of disease and mortality. Environmental exposure to metals might be a causative factor for hypertension, but the association remains unclear. The present case-control study of 502 hypertension patients and 502 healthy participants aimed to evaluate the potential relationships between the concentrations of 20 metal in urine and the risk of hypertension in a Chinese population. Multivariate logistic analyses adjusted for potential confounders were performed separately considering the effects of single and multi-metal. We found the increasing trends of urinary Fe, Co, Ni, Cu, Zn and Sr quartiles and the decreasing trends of urinary V and Rb quartiles with the ORs for hypertension. These dose-response associations were confirmed in the RCS models and remained robust in the multi-metal model. Urinary Hg quartiles were positively associated with the risk of hypertension in the models of single-metal and multi-metal. Urinary Cd quartiles were inversely associated with the risk of hypertension in the multi-metal model. Besides, modification effects of gender, BMI and smoking status on the associations of the exposure to various metals with the risk of hypertension were also suggested in the subgroup analysis. Our findings suggest that environmental exposure to V, Fe, Co, Ni, Cu, Zn, Rb, Sr, Cd and Hg might be related with the prevalence of hypertension. Further studies with prospective design should be conducted to confirm these findings.

Environmental exposure to metals and the risk of hypertension: A cross-sectional study in China

Metal pollution is a severe environmental issue in China, which has been recently linked with the risk of hypertension. However, relevant epidemiological studies are limited. The present exploratory study was conducted to assess the associations of environmental exposure to metals with the odds of hypertension as well as blood pressure (BP) levels using urine samples in a Chinese general population. From May 2016 to April 2017, a total of 823 eligible participants were consecutively enrolled in our study in Wuhan, China. Hypertension was defined as systolic BP (SBP) of ≥140 mmHg or diastolic BP (DBP) of ≥90 mmHg, a self-reported physician diagnosis, or current use of antihypertensive medication. We used urine samples as biomarkers to reflect the levels of environmental exposure to 20 metals. Multivariable regression models were applied to assess the potential association. Multi-metal models were conducted to investigate the impacts of co-exposure to various metals. Based on the results from various models, positive trends for increased odds of hypertension with increasing quartiles of vanadium (V), iron (Fe), zinc (Zn) and selenium (Se) were suggested. Compared with those in the lowest quartiles, participants in the highest quartiles of V, Fe, Zn and Se had a 4.4-fold, 4.9-fold, 4.2-fold and 2.5-fold increased odds of having hypertension, respectively. High urinary Hg level was found to increase the levels of DBP. Individuals in the highest group of Hg were found to have a 4.3 mmHg higher level of DBP. Our findings suggest that environmental exposure to V, Fe, Zn, Se and Hg might increase the risk of hypertension or elevate the levels of BP. These findings warrant further prospective studies in a larger population.

The Response of Macro- and Micronutrient Nutrient Status and Biochemical Processes in Rats Fed on a Diet with Selenium-Enriched Defatted Rapeseed and/or Vitamin E Supplementation

The response of nutrient status and biochemical processes in (i) Wistar and (ii) spontaneously hypertensive (SHR) rats upon dietary intake of selenium- (Se-) enriched defatted rapeseed (DRS) and/or vitamin E fortification was examined to assess the health benefit of DRS in animal nutrition. Twenty-four individuals of each type of rat were used: The control group was fed with an untreated diet (Diet A). In Diets B and C, soybean meal was replaced with defatted DRS, which comprised 14% of the total diet. The selenized DRS application resulted in ~3-fold increase of Se content in the diet. Diet C was also fortified with the addition of vitamin E, increasing the natural content by 30%. The Se content of the blood and kidneys tended to increase in the DRS groups, where the changes were significant (P < 0.05) only in the case of SHR rats. The iodine (I) content and the proportion of iodide in rat livers indicated a lower transformation rate of iodide into organoiodine compounds compared to the control. Slight and ambiguous alterations in the antioxidative response of the rat were observed in the DRS groups, but the addition of vitamin E to the diet helped to moderate these effects.

Cadmium body burden and increased blood pressure in middle-aged American Indians: the Strong Heart Study

Cadmium (Cd) is an environmental pollutant that has been associated with cardiovascular disease in populations, but the relationship of Cd with hypertension has been inconsistent. We studied the association between urinary Cd concentrations, a measure of total body burden, and blood pressure in American Indians, a US population with above national average Cd burden. Urinary Cd was measured using inductively coupled plasma mass spectrometry, and adjusted for urinary creatinine concentration. Among 3714 middle-aged American Indian participants of the Strong Heart Study (mean age 56 years, 41% male, 67% ever-smokers, 23% taking antihypertensive medications), urinary Cd ranged from 0.01 to 78.48 μg g^-1 creatinine (geometric mean=0.94 μg g^-1) and it was correlated with smoking pack-year among ever-smokers (r²=0.16, P<0.0001). Participants who were smokers were on average light-smokers (mean 10.8 pack-years), and urinary Cd was similarly elevated in light- and never-smokers (geometric means of 0.88 μg g^-1 creatinine for both categories). Log-transformed urinary Cd was significantly associated with higher systolic blood pressure in models adjusted for age, sex, geographic area, body mass index, smoking (ever vs never, and cumulative pack-years) and kidney function (mean blood pressure difference by lnCd concentration (β)=1.64, P=0.002). These associations were present among light- and never-smokers (β=2.03, P=0.002, n=2627), although not significant among never-smokers (β=1.22, P=0.18, n=1260). Cd was also associated with diastolic blood pressure among light- and never-smokers (β=0.94, P=0.004). These findings suggest that there is a relationship between Cd body burden and increased blood pressure in American Indians, a population with increased cardiovascular disease risk.

Environment-Wide Association Study of Blood Pressure in the National Health and Nutrition Examination Survey (1999-2012)

Identifying environmental exposures associated with blood pressure is a priority. Recently, we proposed the environment-wide association study to search for and replicate environmental factors associated with phenotypes. We conducted the environment-wide association study (EWAS) using the National Health and Nutrition Examination Surveys (1999–2012) which evaluated a total of 71,916 participants to prioritize environmental factors associated with systolic and diastolic blood pressure. We searched for factors on participants from survey years 1999–2006 and tentatively replicated findings in participants from years 2007–2012. Finally, we estimated the overall association and performed a second meta-analysis using all survey years (1999–2012). For systolic blood pressure, self-reported alcohol consumption emerged as our top finding (a 0.04 increase in mmHg of systolic blood pressure for 1 standard deviation increase in self-reported alcohol), though the effect size is small. For diastolic blood pressure, urinary cesium was tentatively replicated; however, this factor demonstrated high heterogeneity between populations (I² = 51%). The lack of associations across this wide of an analysis raises the call for a broader search for environmental factors in blood pressure.

Non-occupational Lead and Cadmium Exposure and Blood Pressure in Thai Men

In this study, the effects of low level exposure to lead and cadmium on blood pressure among 212 men have been examined. The mean age was 41 years (range 34-53). The means of systolic and diastolic blood pressure were 126 (range 94-159) and 78 (range 58-117) mmHg, respectively. Blood lead concentration ranged from 144.31 to 779.34 ηmol/L with a geometric mean (GM) of 363.11 ηmol/L. Blood cadmium levels ranged from 1.33-37.81ηmol/L with GM of 8.09 ηmol/L. For stepwise regression analysis, an increase in systolic blood pressure was significantly predictive by an increasing blood lead ( p<0.001) whereas blood cadmium showed no significant correlation with blood pressure. Body mass index and alcohol consumption also contributed to both systolic and diastolic blood pressure. These findings also supported our proposal concerning the association between blood lead and blood pressure. Asia Pac J Public Health 2004; 16(2): 133-137.

Clastogenic but Not Apoptotic Effects on Human Artery Endothelial Cells by Concentrations of Inorganic Lead Inhibiting Their Nitric Oxide Production

Human coronary artery endothelial cells (HCAEC 5156) were cultured as monolayers and exposed to concentrations of lead (as acetate, Pb) in the culture medium similar or lower than those commonly found in the blood of human beings occupationally or environmentally exposed to this element. Only at the concentration of 200 ng/mL, Pb reduced growth rate of HCAEC 5156 cells starting from the 3rd day and up to the 5th day of incubation. On the other hand, Pb (0.2, 2 and 200 ng/mL) increased concentration-dependently micronuclei formation in binucleated HCAEC5156 cells, as it was shown by the cytokinesis-blocked micronucleus assay (CBMN assay) carried out after 48 hours of exposure to the metal. However, Pb was unable, at all the above concentrations, to induce apoptosis in HCAEC 5156 cells following a 48 hour-exposure, as shown by an electrophoretic apoptotic DNA fragmentation test. Moreover, Pb (2 and 200 ng/mL) reduced significantly the concentration of nitric oxide (NO, determined analytically as L-citrulline) in both culture medium and cytosol of HCAEC 5156 cells following a 7 day-exposure to the element. Results were discussed also in relation to evidences of other studies reporting genotoxic and/or apoptotic effects of Pb on various cell types at very elevated dosages or concentrations. The observed clastogenic effects of Pb were explained through a series of mechanisms involving interactions between oxygen reactive species and NO and/or reduced NO synthesis in the endothelium, thus leading to a depressed NO bioavailability. This research first shows that Pb is provided with clastogenic but not apoptotic effects on cultured human endothelial cells. It was emphasized that such effects are induced by Pb concentrations similar to those commonly found in blood and tissues of laboratory animals showing Pb induced cardiovascular and/or neuropsychological alterations.

Do people from Taiwan have higher heavy metal levels than those from Western countries?

INTRODUCTION

This study investigated whether heavy metal levels were higher in people from Taiwan as compared to those from Western countries.

METHODS

We measured the level of heavy metals (lead, mercury, arsenic and cadmium) in the blood of 40 apparently healthy adults. Since mercury does not respond to ethylenediaminetetraacetic acid (EDTA) infusion, only urine lead, arsenic and cadmium levels were determined by applying the body burden concept after calcium disodium EDTA infusion. These three heavy metals were extracted from daily urine samples for three consecutive days.

RESULTS

The mean blood lead, mercury and cadmium levels of the Taiwanese individuals (24.46 ± 9.69 µg/L, 9.64 ± 6.98 µg/L and 0.73 ± 0.27 µg/L, respectively) were greater than those of the Americans. The Taiwanese also had greater blood mercury and cadmium levels than the Germans. The first-day urine lead, arsenic and cadmium levels were 77.9%, 33.1% and 62.4%, respectively, of the total lead, arsenic and cadmium excretion during the three days. This indicates that the first-day urine lead and cadmium excretion represented most (> 60%) of the lead and cadmium excretion in those three days.

CONCLUSION

This study demonstrated that the Taiwanese population has higher blood mercury and cadmium levels than Western populations. To study the urine lead and cadmium body burden of patients, detection of first-day, rather than three-day, urine lead and cadmium levels can be done, as the former yields results that are fairly representative, and is more time- and cost-effective.

Influence of abatement of lead exposure in Croatia on blood lead and ALAD activity

We evaluated the effect of lead (Pb) abatement measures in Croatia on blood lead (BPb) concentrations, and delta-aminolevulinic acid dehydratase (ALAD) activity in blood, as a sensitive indicator of early Pb effect. Data on BPb and ALAD activity were obtained from 829 Croatian men (19-64 years of age), with no known occupational exposure to metals. Data obtained in 2008-2009, after the ban of leaded gasoline in Croatia in 2006, were compared with similar data collected in 1981 and 1989, when the concentration of Pb in gasoline was 0.6 g/L. Our results showed a highly significant (p < 0.001) decrease in median BPb from 114.5 (range, 46.0-275.0) μg/L in 1981/1989 to 30.3 (range, 3.2-140.8) μg/L in 2008-2009 and an increase in median ALAD activity from 49.8 (range, 24.9-79.4) EU in 1981/1989 to 60.9 (range, 35.8-84.0) EU in 2008-2009. Individual factors influencing BPb values were, in the order of decreasing importance, Pb in ambient air (APb), alcohol consumption, age, and smoking. Increased ALAD activity was significantly associated with the decrease of APb, alcohol consumption, and smoking. These results show that lead abatement measures had a positive impact on both BPb concentrations (73.5% decrease) and the activity of ALAD (22.1% increase) in general population. Our results contribute to growing evidence that ALAD activity may be used as one of the earliest and sensitive diagnostic biomarkers of low-level Pb exposure.

Possible Relationship between Chronic Telogen Effluvium and Changes in Lead, Cadmium, Zinc, and Iron Total Blood Levels in Females: A Case-Control Study

Introduction:

Hair loss is a common and distressing problem that can affect both males and females of all ages. Chronic telogen effluvium (CTE) is idiopathic diffuse scalp hair shedding of at least 6 months duration. Hair loss can be one of the symptoms of metal toxicity. Lead (Pb) and cadmium (Cd) are highly toxic metals that can cause acute and chronic health problems in human. The aim of the present study is to determine if there is a relationship between these metals and CTE in women and if CTE is also associated with changes in zinc (Zn) or iron (Fe) blood levels.

Materials and Methods:

Pb, Cd, Fe and Zn total blood levels were determined in 40 female patients fulfilling the criteria of CTH and compared with total blood levels of same elements in 30 well-matched healthy women.

Results:

Quantitative analysis of total blood Fe, Zn, Pb and Cd revealed that there were no significant differences between patients and controls regarding Fe, Zn, and Pb. Yet, Cd level was significantly higher in patients than controls. In addition, Cd level showed significant positive correlation with the patient's body weight.

Conclusion:

Estimation of blood Pb and Cd levels can be important in cases of CTE as Cd toxicity can be the underlying hidden cause of such idiopathic condition.

Blood pressure and occupational exposure to noise and lead (Pb): A cross-sectional study

Several studies have explored the hypothesis that low blood lead (PbB) and high noise levels may be associated with an increased risk of hypertension. To assess the possible relationship between occupational exposure to lead (Pb) and noise and elevated blood pressure, we studied 105 workers (age: 41.27 ± 6.25 years and length of employment: 4.12 ± 5.33 years) employed in a Pb battery recycling plant by measuring A-weighted equivalent sound level, PbB, δ-aminolevulinic acid dehydratase (ALAD) activity and zinc protoporphyrin (ZPP) levels and systolic and diastolic blood pressure (SBP and DBP). Results showed that occupational exposure to higher ambient Pb and noise levels was related to slightly increased SBP and DBP. PbB values correlated significantly with SBP and DBP, whereas noise levels correlated neither with SBP nor with DBP. Furthermore, workers exposed to higher ambient Pb had higher PbB and ZPP and showed more decreased ALAD activity. Blood pressure does not correlate with noise exposure but only with PbB concentration.

Benchmark dose estimation of cadmium reference level for hypertension in a Chinese population

Cadmium exposure can cause high blood pressure or hypertension. Benchmark dose has been used to estimate the reference point of cadmium for kidney and bone damage. In this study, we observed the association of blood pressure and cadmium in blood (BCd) and evaluated the reference level of cadmium for hypertension using benchmark dose (BMD) approach. A total of 441 subjects were included in this study. Blood samples were collected from each individual for BCd determination. Blood pressure was measured by electronic sphygmomanometer. BMD and BMDL were calculated using BMD software corresponding to additional risk of 10%. The systolic blood pressure (SBP), diastolic blood pressure (DBP) and prevalence of hypertension increased with the increasing of BCd, especially for SBP (χ(2)=3.9, p=0.047 in men; χ(2)=4.3, p=0.037 in women). With a benchmark response of 10%, the BMDL10 for hypertension (high SBP) was 0.95μg/L and 1.02μg/L for women and men, respectively; the BMDL10 for hypertension (high DBP) was 1.8μg/L and 1.66μg/L for women and men, respectively. Our data evidenced that BCd was associated with elevation in blood pressure and hypertension, especially for women. The reference level of cadmium for hypertension with high SBP was lower than that of high DBP.

Blood levels of lead, cadmium, and mercury in the elderly living in institutionalized care in the Czech Republic

BACKGROUND

There is limited research examining the chemical load of toxic metals in the elderly. The aim of the present study was two-fold: to determine the body burden of lead, cadmium and mercury in association with age, gender, locality, lifestyle factors and potential health impacts among this population and to compare the values with blood values from the general Czech population aged 18-64 years.

METHODS

Lead, cadmium and mercury were examined in the blood of institutionalized senior citizens (46 males, 151 females aged 61-100 years) from two localities in the Czech Republic (Prague and Teplice) from 2009 through 2011. Measurements were made using inductively coupled plasma mass spectrometry (Pb, Cd) and a single purpose spectrometer AMA 254 (Hg).

RESULTS

Geometric means (GM) of whole blood lead (B-Pb), cadmium (B-Cd) and mercury (B-Hg) levels were 25.3μg/l, 0.55μg/l and 0.21μg/l, respectively. No age-related differences were found for B-Pb and B-Cd levels but a negative correlation with age was observed for B-Hg levels (p=0.04). B-Pb levels in men were significantly higher than in women (GM 29.9μg/l vs. 24.1μg/l). B-Cd was significantly higher in women (GM 0.57μg/l) than in men (0.50μg/l) (p=0.007) and in smokers (GM 1.29μg/l) than in nonsmokers (GM 0.53μg/l) (p=<0.001) and in seniors from Prague (GM 0.60μg/l) compared to those from Teplice (GM 0.43μg/l) (p=<0.001). Seniors with a history of chronic kidney disease, stroke and those using psycho-pharmaceuticals had higher B-Pb levels (p=0.008, 0.04 and 0.05, resp.), seniors diagnosed with atherosclerosis had higher B-Cd levels (p=0.002) and seniors using psycho-pharmaceuticals had higher B-Hg levels (p=0.07). B-Hg levels were also positively correlated with blood albumin levels (p=0.015).

CONCLUSIONS

This study provides data on levels of heavy metals in a group of elderly people. Such information is very scarce. Associations with diseases should be the subject of further investigation.

The relationship between environmental exposure to cadmium and lead and blood selenium concentration in randomly selected population of children inhabiting industrial regions of Silesian Voivodship (Poland)

This study aimed at determining the relationship between environmental exposure to lead (Pb) and cadmium (Cd) and blood selenium (Se) concentration in randomly selected population of children inhabiting the industrial regions of Silesian Voivodship, Poland. The study was conducted on a group of consecutive randomly selected 349 children aged below 15 years and inhabiting the industrial regions in Upper Silesia. The examined variables included whole blood Cd concentration (Cd-B), whole blood Pb concentration (Pb-B) and whole blood Se concentration (Se-B). The concentration of Cd-B, Pb-B and Se-B in the studied group of children amounted to 0.26 ± 0.14, 37.62 ± 25.30 and 78.31 ± 12.82 μg/L, respectively. In the entire examined group a statistically significant negative linear relationship was noted between Pb-B and Se-B (r = -0.12, p < 0.05). Also, a statistically insignificant negative correlation was detected between Cd-B and Se-B (r = -0.02, p > 0.05) and a statistically insignificant positive correlation between Pb-B and Cd-B (r = 0.08, p > 0.05). A multivariate backward stepwise regression analysis demonstrated that in the studied group of children higher Pb-B and a more advanced age-represented independent risk factors for a decreased Se-B. Environmental exposure to Pb may represent an independent risk factor for Se deficit in blood of the studied population of children. In children, the lowered Se-B may create one of the mechanisms in which Pb unfavourably affects human body.

Heart function in magnetic resonance imaging and the mesenteric artery reactivity in rats receiving lead-contaminated drinking water

The aim of this study was to evaluate the effect of lead (Pb)-contaminated drinking water on magnetic resonance imaging (MRI)-estimated cardiac function, vascular reactivity, and serum lipids in rats. For 3 months, male Wistar rats, aged 4–6 weeks, were given drinking water with the addition of lead acetate at a concentration of 100 ppm Pb (10 rats) or water free from Pb (8 control rats). The cardiac MRI was performed at rest and under β-adrenergic stimulation on a 4.7 T scanner using electrocardiogram-triggered gradient echo (FLASH) cine sequence. After 1–2 weeks of the MRI test, experiments were performed ex vivo. After stabilization of perfusion pressure (PP), norepinephrine at doses from 0.01 to 5.0 μg was dissolved in Krebs solution, injected in a volume of 100 μl, and next infused at a concentration of 0.5 μg/ml into the isolated mesenteric artery. In this manner, preconstricted mesenteric bed was used to determine PP changes induced by acetylcholine, given at doses from 0.05 to 5.0 μg, before and during the infusion of nitric oxide synthase inhibitor (1.0 μg/ml). At the end, dobutamine (5 mg), followed by potassium chloride (10.5 mg), was injected. Lipid levels were determined enzymatically, blood Pb level was measured by the atomic absorption spectrophotometer. This study showed that Pb impairs the left ventricular systolic and diastolic function. Pb-induced changes in response to resistance of vessels to vasoactive agents may be secondary to the reduced left ventricular ejection fraction. The high-density lipoprotein subfraction 2 (HDL2) is involved in the cardiovascular effect of Pb.

Selenium levels and hypertension: a systematic review of the literature

OBJECTIVE

Se is an antioxidant micronutrient and has been studied for its potential role in CVD prevention. The purpose of the present study was to conduct a systematic review of the literature on the relationship between Se and hypertension.

DESIGN

We conducted a systematic literature search in PubMed and OVID of studies on Se levels and hypertension or blood pressure published in English up to June 2011. Articles meeting inclusion criteria were reviewed and the following information was gathered from each publication: study setting, participant demographics, exclusion criteria, intervention if applicable, medium of Se measure, mean level of Se, outcome definition, relationship between Se and the outcome variable, significance of this relationship, and covariates. In studies that also reported glutathione peroxidase levels, we extracted results on the relationship between glutathione peroxidase and hypertension.

RESULTS

Twenty-five articles were included. Approximately half of the studies reported no significant relationship between Se and hypertension. Of the remaining studies, about half found that higher Se levels were associated with lower blood pressure and the other half found the opposite relationship. The studies varied greatly in terms of study population, study design and Se levels measured in participants.

CONCLUSIONS

Based on the present systematic review, there is no conclusive evidence supporting an association between Se and hypertension. Randomized controlled trials and prospective studies with sufficient sample size in populations with different Se levels are needed to fully investigate the relationship between Se and hypertension.

Metals in wine--impact on wine quality and health outcomes

Metals in wine can originate from both natural and anthropogenic sources, and its concentration can be a significant parameter affecting consumption and conservation of wine. Since metallic ions have important role in oxide-reductive reactions resulting in wine browning, turbidity, cloudiness, and astringency, wine quality depends greatly on its metal composition. Moreover, metals in wine may affect human health. Consumption of wine may contribute to the daily dietary intake of essential metals (i.e., copper, iron, and zinc) but can also have potentially toxic effects if metal concentrations are not kept under allowable limits. Therefore, a strict analytical control of metal concentration is required during the whole process of wine production. This article presents a critical review of the existing literature regarding the measured metal concentration in wine, methods applied for their determination, and possible sources, as well as their impact on wine quality and human health. The main focus is set on aluminum, arsenic, cadmium, chromium, copper, iron, manganese, nickel, lead, and zinc, as these elements most often affect wine quality and human health.

Comparative study on the efficacy of Allium sativum (garlic) in reducing some heavy metal accumulation in liver of wistar rats

SCOPE

Heavy metals are known to cause damage through indirect oxidative effects. This study was undertaken to compare the therapeutic efficacy and protective ability of garlic extracts on reducing toxicity induced by mercury, lead and cadmium in the liver.

METHODS AND RESULTS

Rats were fed with rat chow mixed with raw garlic (7% w/w) while mercury (10ppm), cadmium (200ppm) and lead (100ppm) were given in drinking water. Garlic was administered either at the same time with the metals (group 2), a week after exposure to heavy metals (group 3) or a week before heavy metal exposure (group 4) for 6weeks. The heavy metal accumulations in the liver were determined using AAS. The percentage protection showed a time-dependent effect and was significantly (P<0.01) higher for cadmium compared to mercury and lead-treated groups. Analysis between the groups showed that garlic treatment after exposure had a significantly (P<0.05) higher percentage protection when compared with other modes.

CONCLUSION

These results suggest that garlic offered more hepatoprotective effect to cadmium followed by mercury and least protection to lead at the selected dose of each metal in this study through the processes of uptake, assimilation and elimination of these metals.

Comparative study on the efficacy of Garcinia kola in reducing some heavy metal accumulation in liver of Wistar rats

Garcinia kola is regarded as an antidote and anti-hepatotoxic agent. We examined its protection ability against mercury (Hg), lead (Pb) and cadmium (Cd) accumulation in the liver. The ground seed was mixed with rat feed (5%, w/w) and fed to rats while Hg (10 ppm), Cd (200 ppm) and Pb (100 ppm) was given in drinking water. Garcinia kola was administered either at the same time with the metals (group 2), a week after exposure to heavy metals (group 3) or given a week before heavy metal exposure (group 4) for six weeks. The heavy metal accumulations in the liver were determined using AAS. Garcinia kola could not reverse the weight reduction in the heavy metal exposed groups although it offers more protection and aid greater elimination of heavy metals from the liver. There was a significant (P<0.01) increase in protection by Garcinia kola to Cd (72.4%) and Pb (56.2%) accumulation when compared to Hg (40%) at week 2 which was significantly (P<0.01) decreased at week 4 when compared to week 2. At week 6, the percentage protection to both Hg (64.2%) and Cd (62.2%) were comparable to each other while protection to Pb (49.9%) accumulation was significantly (P<0.01) reduced. The percentage protection was time-dependent in some groups but treatment during and after the exposure provided a greater protection. Garcinia kola has the highest hepatoprotective effect to Cd followed by Hg and least protection against Pb toxicity in rats and its administration is beneficial in reducing heavy metal accumulation in the liver.

Antioxidants, trace elements and metabolic syndrome in elderly subjects

OBJECTIVE

To examine whether concentrations of several trace elements and activities of several antioxidant enzymes are modified in metabolic syndrome, and to evaluate their possible association with metabolic syndrome components. Additionally, concentration of CRP, as a marker of inflammation, was measured.

DESIGN

Cross-sectional study.

PARTICIPANTS

The study group consisted of 100 subjects, aged 71-88 years.

MEASUREMENTS

Anthropometric measurements and biochemical analyses of fasting blood samples were performed by standardized methods. According to the International Diabetic Federation (IDF) criteria, metabolic syndrome was diagnosed in 64 subjects. Whole blood glutathione peroxidase (GPx), erythrocyte superoxide dismutase (SOD) and catalase (CAT), serum selenium (SSe), copper (SCu) and zinc (SZn), glucose, lipoprotein profile and C-reactive protein (CRP) were determined in all subjects.

RESULTS

No clear influence of metabolic syndrome on SSe, SZn and SCu concentration and SOD and CAT activity was found. However, significantly higher GPx was found in subjects with metabolic syndrome than in subjects without metabolic syndrome (p=0.029), as well as in subjects with hypertriglyceridemia than in control subjects (p=0.038). After adjusting for potentially confounding variables by multiple regression, significant positive relationship between SCu and CRP was found, indicating that elevated levels of Cu could have influence on inflammatory mechanisms.

CONCLUSION

Our results suggest that GPx and CRP, as biomarkers of oxidative stress and chronic inflammation, respectively, have significant role in the pathogenesis of metabolic syndrome.

Blood and urine cadmium, blood pressure, and hypertension: a systematic review and meta-analysis

BACKGROUND

Cadmium exposure has been inconsistently related to blood pressure.

OBJECTIVES

We updated and reevaluated the evidence regarding the relationships of blood cadmium (BCd) and urine cadmium (UCd) with blood pressure (BP) and hypertension (HTN) in nonoccupationally exposed populations.

DATA SOURCES AND EXTRACTION

We searched PubMed and Web of Science for articles on BCd or UCd and BP or HTN in nonoccupationally exposed populations and extracted information from studies that provided sufficient data on population, smoking status, exposure, outcomes, and design.

DATA SYNTHESIS

Twelve articles met inclusion criteria: eight provided data adequate for comparison, and five reported enough data for meta-analysis. Individual studies reported significant positive associations between BCd and systolic BP (SBP) among nonsmoking women [ß = 3.14 mmHg per 1 μg/L untransformed BCd; 95% confidence interval (CI), 0.14-6.14] and among premenopausal women (ß = 4.83 mmHg per 1 nmol/L log-transformed BCd; 95% CI, 0.17-9.49), and between BCd and diastolic BP (DBP) among women (ß = 1.78 mmHg comparing BCd in the 90th and 10th percentiles; 95% CI, 0.64-2.92) and among premenopausal women (ß = 3.84 mmHg per 1 nmol/L log-transformed BCd; 95% CI, 0.86-6.82). Three meta-analyses, each of three studies, showed positive associations between BCd and SBP (p = 0.006) and DBP (p < 0.001) among women, with minimal heterogeneity (I² = 3%), and a significant inverse association between UCd and HTN among men and women, with substantial heterogeneity (I² = 80%).

CONCLUSION

Our results suggest a positive association between BCd and BP among women; the results, however, are inconclusive because of the limited number of representative population-based studies of never-smokers. Associations between UCd and HTN suggest inverse relationships, but inconsistent outcome definitions limit interpretation. We believe a longitudinal study is merited.

Modification by ALAD of the association between blood lead and blood pressure in the U.S. population: results from the Third National Health and Nutrition Examination Survey

BACKGROUND

Environmental lead exposure has been found to be associated with an increased risk of hypertension. Individuals vary greatly in susceptibility to lead toxicity, and genetic susceptibility has often been cited as the probable cause for such variation.

OBJECTIVE

The main objective is to determine the role of the aminolevulinic acid dehydratase (ALAD) gene, which encodes the main carrier protein of lead in blood, in the association between lead exposure and blood pressure (BP) and hypertension in the U.S. population.

METHODS

We analyzed data from individuals >or= 17 years of age who participated in the Third National Health and Nutrition Examination Survey for whom DNA was available (n = 6,016). Multivariable logistic and linear regressions stratified by race/ethnicity were used to examine whether hypertension and BP were associated with ALAD and blood lead levels (BLL).

RESULTS

BLL was associated with systolic BP in non-Hispanic whites and with hypertension and systolic and diastolic BP in non-Hispanic blacks. BLL was not associated with BP outcomes in Mexican Americans. Non-Hispanic white ALAD2 carriers in the highest BLL quartile (3.852.9 microg/dL) had a significantly higher adjusted prevalence odds ratio for hypertension compared with ALAD1 homozygous individuals. We also found a significant interaction between lead concentration and the ALAD2 allele in non-Hispanic whites and non-Hispanic blacks in relation to systolic BP.

CONCLUSIONS

BLL may be an important risk factor for hypertension and increased systolic and diastolic BP. These associations may be modified by ALAD genotype.

Blood lead level and cardiovascular risk factors among bus drivers in Bangkok, Thailand

This study aimed to clarify the role of blood lead level (Pb-B) as one of the cardiovascular risk factors. To evaluate the cardiovascular risk the second derivative finger photoplethysmogram (SDPTG) was used. The subjects comprised of 420 male bus drivers in Thailand. The subjects' age ranged from 20 to 60 yr. Mean age (+/- standard deviation) were 41.6 (+/- 7.7) yr. Mean working years was 8.8 (+/- 6.8) yr. Pb-B ranged from 2.5 to 16.2 microg/dl with the mean Pb-B of 6.3 (+/- 2.2) microg/dl. The mean of aging index of SDPTG (SDPTG-AI) were -0.50 (+/- 0.30). The SDPTG-AI increases with age, Pb-B, smoking and alcohol consumption. There was significant correlation between Pb-B and SDPTG-AI after controlling for age, body mass index and lifestyle factors. These results suggest that Pb-B is possibly an independent cardiovascular risk factor for bus drivers exposed to lower level of lead.

Postnatal cadmium exposure, neurodevelopment, and blood pressure in children at 2, 5, and 7 years of age

BACKGROUND

Adverse health effects of cadmium in adults are well documented, but little is known about the neuropsychological effects of cadmium in children, and no studies of cadmium and blood pressure in children have been conducted.

OBJECTIVE

We examined the potential effects of low-level cadmium exposure on intelligence quotient, neuropsychological functions, behavior, and blood pressure among children, using blood cadmium as a measure of exposure.

METHODS

We used the data from a multicenter randomized clinical trial of lead-exposed children and analyzed blood cadmium concentrations using the whole blood samples collected when children were 2 years of age. We compared neuropsychological and behavioral scores at 2, 5, and 7 years of age by cadmium level and analyzed the relationship between blood cadmium levels at 2 years of age and systolic and diastolic blood pressure at 2, 5, and 7 years of age.

RESULTS

The average cadmium concentration of these children was 0.21 microg/L, lower than for adults in the National Health and Nutrition Examination Survey (NHANES), but comparable to concentrations in children < 3 years of age in NHANES. Except for the California Verbal Learning Test for Children, there were no differences in test scores among children in different cadmium categories. For children with detectable pretreatment blood cadmium, after adjusting for a variety of covariates, general linear model analyses showed that at none of the three age points was the coefficient of cadmium on Mental Development Index or IQ statistically significant. Spline regression analysis suggested that behavioral problem scores at 5 and 7 years of age tended to increase with increasing blood cadmium, but the trend was not significant. We found no significant associations between blood cadmium levels and blood pressure.

CONCLUSION

We found no significant associations between background blood cadmium levels at 2 years of age and neurodevelopmental end points and blood pressure at 2, 5, and 7 years of age. The neuropsychological or hypertensive effects from longer background exposures to cadmium need further study.

Reproductive toxicity of low-level lead exposure in men

Parameters of semen quality, seminal plasma indicators of secretory function of the prostate and seminal vesicles, sex hormones in serum, and biomarkers of lead, cadmium, copper, zinc, and selenium body burden were measured in 240 Croatian men 19-52 years of age. The subjects had no occupational exposure to metals and no known other reasons suspected of influencing male reproductive function or metal metabolism. After adjusting for age, smoking, alcohol, blood cadmium, and serum copper, zinc, and selenium by multiple regression, significant (P<0.05) associations of blood lead (BPb), delta-aminolevulinic acid dehydratase (ALAD), and/or erythrocyte protoporphyrin (EP) with reproductive parameters indicated a lead-related increase in immature sperm concentration, in percentages of pathologic sperm, wide sperm, round sperm, and short sperm, in serum levels of testosterone and estradiol, and a decrease in seminal plasma zinc and in serum prolactin. These reproductive effects were observed at low-level lead exposure (BPb median 49 microg/L, range 11-149 microg/L in the 240 subjects) common for general populations worldwide. The observed significant synergistic effect of BPb and blood cadmium on increasing serum testosterone, and additive effect of a decrease in serum selenium on increasing serum testosterone, may have implications on the initiation and development of prostate cancer because testosterone augments the progress of prostate cancer in its early stages.

Blood lead level and blood pressure of bus drivers in Bangkok, Thailand

This study aims to evaluate blood lead level (PbB) and blood pressure of bus drivers in Bangkok, Thailand, after the phasing out of lead in gasoline. The subjects comprised of 439 male bus drivers whose age ranged between 23 and 59 yr with the mean age of 42 +/- 8 yr. Average working experience was 10 +/- 7 yr. The mean of the systolic and diastolic blood pressure were 131 +/- 17 and 81 +/- 11 mmHg, respectively. PbB ranged from 2.5 to 16.2 microg/dl with the mean PbB of 6.3 microg/dl. Prevalence rate of systolic and diastolic hypertension among bus drivers were 23.0% and 18.2%, respectively. There were significant correlations between PbB and blood pressure both in systolic and diastolic blood pressure after controlling for age, BMI, alcohol consumption, smoking and physical exercise. However, the data on psycho-social factors which may affect on blood pressure of bus drivers were not available. Therefore, further study is needed to clarify the relationship between blood pressure and psycho-social stress among bus drivers in Bangkok. These findings suggested lead exposure at low PbB is related to increases in blood pressure.

Factors associated with longitudinal plasma selenium decline in the elderly: the EVA study

Selenium status decreases in elderly populations. Cardiovascular diseases are the primary cause of death in the French elderly, and selenium may protect against cardiovascular diseases. The present work aims to evaluate the relationships between cardiovascular-related risk factors and plasma selenium variability in an elderly population during a 9-year period. Seven hundred fifty-one subjects from the EVA ("Etude du Vieillissement Artériel") study, aged 59 to 71 at baseline, were followed for 9 years. Clinical examinations and lifestyle questionnaires were repeated every 2 years. Plasma selenium determinations were performed at baseline and at the end of the study. The association between the 9-year plasma selenium variability and studied risk factors at baseline or occurring during the follow-up was evaluated by using multivariate linear regression models. After controlling all potential associated factors, age of subjects (P<.01), obesity (P=.02) and occurrence of cardiovascular disease during follow-up (P=.03) increased the longitudinal decline in plasma selenium, whereas gender, education, smoking, alcohol intakes, dyslipidemia, diabetes, hypertension had no effect (P>.05). It may be postulated that obesity and occurrence of cardiovascular events are the main factors associated with plasma selenium fall during ageing. The respective roles played by nutritional and metabolism changes in the mechanism of these associations still need to be explored.

Blood Lead Below 0.48 μmol/L (10 μg/dL) and Mortality Among US Adults

Background— Blood lead levels above 0.48 μmol/L (10 μg/dL) in adults have been associated with increased risk of cardiovascular, cancer, and all-cause mortality. The objective of the present study was to determine the association between blood lead levels below 0.48 μmol/L and mortality in the general US population.

Methods and Results— Blood lead levels were measured in a nationally representative sample of 13 946 adult participants of the Third National Health and Nutrition Examination Survey recruited in 1988 to 1994 and followed up for up to 12 years for all-cause and cause-specific mortality. The geometric mean blood lead level in study participants was 0.12 μmol/L (2.58 μg/dL). After multivariate adjustment, the hazard ratios (95% CI) for comparisons of participants in the highest tertile of blood lead (≥0.17 μmol/L [≥3.62 μg/dL]) with those in the lowest tertile (<0.09 μmol/L [<1.94 μg/dL]) were 1.25 (1.04 to 1.51; P trend across tertiles=0.002) for all-cause mortality and 1.55 (1.08 to 2.24; P trend across tertiles=0.003) for cardiovascular mortality. Blood lead level was significantly associated with both myocardial infarction and stroke mortality, and the association was evident at levels >0.10 μmol/L (≥2 μg/dL). There was no association between blood lead and cancer mortality in this range of exposure.

Conclusions— The association between blood lead levels and increased all-cause and cardiovascular mortality was observed at substantially lower blood lead levels than previously reported. Despite the marked decrease in blood lead levels over the past 3 decades, environmental lead exposures remain a significant determinant of cardiovascular mortality in the general population, constituting a major public health problem.

Relationship of blood lead levels to blood pressure in exhaust battery storage workers

Several researches has focused the hypothesis that low blood lead levels could be associated with an increased risk of hypertension. To assess the relation between occupational lead exposure and elevated blood pressure a group of 27 workers, age range from 27 to 62 years, mean (SD) 36.52 (+/- 8.16) yr; length of employment mean (DS) 2.97 (+/- 1.67) yr, were recruited as study subjects. The following variables were measured: blood lead concentration (BPb), delta-Aminolevulinic Acid Dehydratase (ALAD) activity, Zinc Protoporphirin (ZPP), creatinine, hematocrit, Body Mass Index (BMI) and Systolic Blood Pressure (SBP) and Diastolic Blood (DBP) Pressure. The results showed that long term occupational exposure was related to a slight increase of systolic and diastolic blood pressure among workers who had been exposed to higher level of lead with respect to workers exposed to lower level of lead. Furthermore, blood lead concentration (BPb) and ZPP resulted higher among workers exposed to higher level of ambient lead, while in the same group of workers ALAD activity resulted more inhibited. The authors concluded long term cumulative lead exposure can significantly increase blood pressure in low level Pb exposed workers.

Serum selenium determinants in French adults: the SU.VI.M.AX study

The objective of the present work was to assess the relationship between serum Se concentrations and environmental determinants (i.e. lifestyle, social activity, geographic region, urban status, education, familial status, physical activity, BMI, tobacco, and food and alcohol consumption). Baseline results from 13 017 subjects (7876 women aged 35-60 and 5141 men aged 45-60) who participated in the SU.VI.M.AX (Supplémentation en Vitamines et Minéraux Antioxydants) study were analysed. Fewer than 2 % of the volunteers had a serum Se status under 0.75 micromol/l, which has been quoted as the cut-off of biological Se sub-deficiency. Women had significantly lower serum Se concentrations than men (1.09 (sd 0.19) micromol/l (n 7423) and 1.14 (sd 0.20) micromol/l (n 4915), P<0.0001, respectively). Significant differences in serum Se concentrations were observed between geographic areas. In both sexes, the serum Se concentration increased with alcohol, meat and fish consumption, and decreased with smoking. In premenopausal women, the serum Se concentration was higher in contraceptive-pill users than in non-users. In women only, age was associated with increased serum Se concentrations, and obesity (BMI> or =30 kg/m2) was associated with decreased serum Se levels. In men, we observed a decrease in serum Se concentrations with increased consumption of vegetables and fruits. In conclusion, though few of the volunteers participating in the SU.VI.M.AX study had Se status in the sub-deficiency range, 83 % of women and 75 % of men had serum concentrations below the value considered optimal for glutathione peroxidase activity. The largest Se associations in both sexes were found with regions, smoking, alcohol, meat and fish consumption. Further studies are needed to understand the difference in Se status between genders.

Environmental lead level and pregnancy-induced hypertension

Previous studies have suggested that environmental lead exposure increases the risk of hypertension in the general population. In this article, the authors used the 1998 linked birth/infant death database of the United States to examine the association between environmental lead level and the occurrence of pregnancy-induced hypertension (PIH). Yearly summaries of environmental lead levels were abstracted from the US Environmental Protection Agency's air pollution databases, and linked with birth/infant death records by state codes. Generalized estimating equations (GEEs) were used to evaluate the odds ratios of PIH associated with environmental lead measured at ecological levels, with adjustment for maternal age, race, education level, marital status, parity, and adequacy of prenatal care measured at individual levels, stratified by maternal cigarette smoking. A total of 2,994,072 women pregnant in 1998 were included in this study. With the first quartile of lead level as the reference group, the odds ratio for PIH among all study subjects in the second quartile of seasonal average lead level at conception was 1.07 (95% CI: 1.05-1.08), and odds ratios in the third and fourth quartiles were 1.22 (95% CI: 1.20-1.25) and 1.16 (95% CI: 1.15-1.18), respectively. The odds ratios for the second, third, and fourth quartiles of seasonal average lead level at birth were 1.07 (95% CI: 1.05-1.09), 1.21 (95% CI: 1.19-1.23), and 1.15 (95% CI: 1.13-1.17), respectively. The risk of PIH increased by 4% per 0.05 microg/m3 increase in seasonal average lead level at conception and birth, in both smokers and nonsmokers. These results suggest that higher environmental lead levels increase the risk of PIH.

Dietary intake and health effects of selected toxic elements

Anthropogenic activities have being contributing to the spread of toxic chemicals into the environment, including several toxic metals and metalloids, increasing the levels of human exposure to many of them. Contaminated food is an important route of human exposure and may represent a serious threat to human health. This mini review covers the health effects caused by toxic metals, especially Cd, Hg, Pb and As, the most relevant toxic elements from a human health point of view.

Lead effect on blood pressure in moderately lead-exposed male workers

BACKGROUND

The effect of lead (Pb) and potential confounding variables on blood pressure was examined in healthy male industrial workers 20-43 years of age.

METHODS

In 100 Pb workers and 51 reference subjects, the following variables were measured: blood Pb (BPb), activity of delta-aminolevulinic acid dehydratase (ALAD), erythrocyte protoporphyrin (EP), blood cadmium (BCd), serum zinc (SZn), serum copper (SCu), hematocrit (Hct), body mass index (BMI), and blood pressure. The inter-relationship of biomarkers of Pb (BPb, ALAD, EP) and BCd, SZn, SCu, Hct, BMI, age, smoking, and alcohol to systolic and diastolic blood pressure was calculated by forward stepwise multiple regression.

RESULTS

There was no significant difference in blood pressure between the two groups, possibly because the reference subjects had relatively high BPb levels and significantly higher BMI (P < 0.05) as compared to the Pb workers. According to the multiple regression results in Pb workers, an increase in systolic blood pressure was significantly associated with increasing EP (P = 0.001) and BMI (P < 0.002), or alternatively with increasing BMI (P < 0.004) and decreasing ALAD (P < 0.04) and BCd (P < 0.05). An increase in diastolic blood pressure was significantly associated with increasing BMI (P < 0.009) and EP (P = 0.05) and decreasing BCd (P < 0.04). With respect to the EP range of 0.73-13.94 micromol/l erythrocytes in 100 Pb workers, an increase of 17 mm Hg in systolic and 6 mm Hg in diastolic blood pressure was found.

CONCLUSIONS

Long-term cumulative Pb exposure, which is better reflected by EP than by ALAD or current BPb level, can significantly increase blood pressure in moderately Pb-exposed male workers (long-term average BPb <400 microg/l; exposure duration 2-21 years).

Lead and other metals in gestational hypertension

OBJECTIVES

To identify any effects that lead, calcium, magnesium, and zinc may have on the development of gestational hypertension.

METHODS

Third-trimester 110 normotensive and 33 gestational hypertension cases were assayed for various metal levels, using standard techniques, including atomic absorption spectrometry.

RESULTS

Gestational hypertension cases showed significantly higher blood lead levels than normotensives. No differences were noticed regarding calcium (ionized and total), magnesium, and zinc levels. Blood lead was significantly related with blood pressure, even after correcting for the body mass indices and age. Blood pressure levels showed no relation to the other analyzed metals. However, the lead:ionized calcium ratio showed a stronger association with blood pressure, than lead alone. Blood lead showed a significant negative relationship with ionized calcium, but none with the other metals.

CONCLUSIONS

Blood lead evidently influenced blood pressure increments and gestational hypertension development. This implies that all efforts should be made to reduce the population's exposure.

Serum calcium, zinc, and copper in relation to biomarkers of lead and cadmium in men

The influence of exposure to lead and cadmium on serum concentrations of calcium, zinc, and copper was examined in 299 healthy Croatian men 20-55 years of age, including 143 workers in a lead battery factory and 156 control subjects. The interrelationship of blood lead, activity of delta-aminolevulinic acid dehydratase, erythrocyte protoporphyrin, blood cadmium, age, smoking habits, and alcohol consumption with respect to serum calcium, zinc, and copper levels was calculated by forward stepwise multiple regression. The results showed that chronic moderate exposure to lead decreased serum zinc, calcium and, to a lesser extent, copper levels. Exposure to cadmium occurred mostly through smoking and seemed to contribute to a decrease of serum zinc. All changes in serum concentrations of these essential elements were significant but remained within the normal range. The results suggest possible mechanisms of lead- and/or cadmium-induced adverse health effects in humans.