Strategies for inducing and validating zinc deficiency and zinc repletion

Given the growing interest in the role of zinc in the onset and progression of diseases, there is a crucial demand for reliable methods to modulate zinc homeostasis. Using a dietary approach, we provide validated strategies to alter whole-body zinc in mice, applicable across species. For confirmation of zinc status, animal growth rates as well as plasma and urine zinc levels were evaluated. The accessible and cost-effective methodology outlined will increase scientific rigor, ensuring reproducibility in studies exploring the impact of zinc deficiency and repletion on the onset and progression of diseases.NEW & NOTEWORTHY This methods paper details dietary approaches to alter zinc homeostasis in rodents and qualitative and quantitative methods to ensure the zinc status of experimental animals. The outlined accessible and cost-effective protocol will elevate scientific rigor, ensuring reproducibility in studies exploring the impact of zinc deficiency and repletion on the onset and progression of a multitude of health conditions and diseases.

Association between urinary zinc excretion and isoflavone-metabolizing enterotypes among Japanese females: a cross-sectional study

BACKGROUND

Zinc absorption and competition among gut bacteria have been reported in animal studies. Thus, gut bacteria may modify zinc availability in humans. Metabolism of intestinal bacteria is known to be necessary for the activation of several phytoconstituents in the body. For example, equol, a typical substance of soybean isoflavone, is produced by intestinal bacteria metabolizing daidzein and the enterotype is one of distinct ones among Japanese population. The difference in the intestinal microflora can modify the bioavailability of zinc. In this study, we examined urinary zinc concentrations in adult female equol producers (EQPs).

METHODS

Urine samples from women participating in health examinations in Miyagi, Okinawa, Kyoto, Kochi, and Hokkaido prefectures were used; from total 17,484 samples, approximately 25 samples were randomly selected for each age group from 30 to 60 years per region (subsample: n = 520), and 520 samples with available urinary zinc concentration (determined by flame atomic absorption analysis) and enterobacterial type were analyzed. EQP was defined as log(equol/daidzein) ≥ -1.42, and urinary concentrations were corrected for creatinine concentration. Urinary zinc concentrations were compared by Student's t-test and multiple regression analyses.

RESULTS

The geometric mean urinary zinc concentration (µg/g-Cr) was lower in EQP than in non-EQP (p = 0.0136 by t-test after logarithm transformation). On the other hand, there was no correlation between urinary zinc concentration with daidzein (r = -0.0495, P = 0.436) and equol concentrations (r = -0.0721, P = 0.256). There was a significant negative association between urinary zinc concentration and EQP (β = -0.392, P = 0.0311) after adjusting with other potential confounding variables, such as daidzein intake.

CONCLUSIONS

The results suggest that gut bacteria that produce equol are involved in the metabolism of zinc. Based on previous studies, the bacteria that affect the metabolism of both substances are thought to be Enterococcus. Future studies are expected to identify specific intestinal bacteria for zinc availability and understand individual differences in the effects of micronutrients.

The impact of essential and toxic elements on cardiometabolic risk factors in adults and older people

BACKGROUND AND AIM

Evidence suggests an association between essential and toxic elements and the worsening of cardiometabolic risk factors. This study aimed to investigate the concentrations of zinc, copper, selenium, arsenic, cadmium, and mercury and their relationship with cardiometabolic risk factors in adults and older people.

METHODS

This cross-sectional study was carried out with 112 adults with a mean age of 59 (sd 14) years old and a BMI of 29.30 (sd 5.11) Kg/m². The subject's weight and height were measured for body mass index (BMI) calculation, classified according to the cut-off points recommended by the World Health Organization (WHO). We evaluated sociodemographic, clinical, lifestyle, waist circumference - WC, visceral adiposity index - VAI, glycemic lipid profile, blood pressure, and high-sensitive C-reactive protein (hs-CRP). Cardiovascular risk was defined by The Global Risk Score (GRS) score. Plasma zinc, selenium, copper levels, urinary arsenic, cadmium, and mercury levels were measured using the inductively coupled plasma mass spectrometry technique (ICP-MS).

RESULTS

There was a negative association between urinary arsenic and VAI (β - 0.03, p < 0.01), triglycerides (β - 1.10, p < 0.01), and VLDL cholesterol (β - 0.14, p = 0.02). Plasma copper and copper/zinc ratio were positively associated with fasting glucose and hs-CRP (β 0.38, p < 0.01; β 36.02, p = 0.01, β 0.004, p < 0.01, β 0.68, p < 0.001, respectively). Urinary arsenic (β - 0.14, p = 0.04) and cadmium (β - 36.42, p = 0.04) were negatively associated with systolic blood pressure. Also, urinary cadmium was negatively associated with diastolic blood pressure (β - 21.55, p = 0.03), and urinary mercury showed an opposite behavior (β 1.45, p = 0.03).

CONCLUSION

Essential and toxic elements in urine and plasma could be potential biomarkers for cardiovascular risk factors. A healthy lifestyle should be adopted; in addition, government policies should be developed to guarantee sustainable production and a safe environment.

Spatial analysis of urine zinc (Zn) concentration for women of reproductive age and school age children in Malawi

Zinc (Zn) is an essential micronutrient, and Zn deficiency remains a major global public health challenge. Recognised biomarkers of population Zn status include blood plasma or serum Zn concentration and proxy data such as dietary Zn intake and prevalence of stunting. Urine Zn concentration is rarely used to assess population Zn status. This study assessed the value of urine Zn concentration as a biomarker of population Zn status using a nationally representative sample of non-pregnant women of reproductive age (WRA) and school-aged children (SAC) in Malawi. Spot (casual) urine samples were collected from 741 WRA and 665 SAC. Urine Zn concentration was measured by inductively coupled plasma mass spectrometry with specific gravity adjustment for hydration status. Data were analysed using a linear mixed model with a spatially correlated random effect for between-cluster variation. The effect of time of sample collection (morning or afternoon), and gender (for SAC), on urine Zn concentration were examined. There was spatial dependence in urine Zn concentration between clusters among SAC but not WRA, which indicates that food system or environmental factors can influence urine Zn concentration. Mapping urine Zn concentration could potentially identify areas where the prevalence of Zn deficiency is greater and thus where further sampling or interventions might be targeted. There was no evidence for differences in urine Zn concentration between gender (P = 0.69) or time of sample collection (P = 0.85) in SAC. Urine Zn concentration was greater in afternoon samples for WRA (P = 0.003). Relationships between urine Zn concentration, serum Zn concentration, dietary Zn intake, and potential food systems covariates warrant further study.

High-Performance Flexible Electrochemical Heavy Metal Sensor Based on Layer-by-Layer Assembly of Ti3C2Tx/MWNTs Nanocomposites for Noninvasive Detection of Copper and Zinc Ions in Human Biofluids

A flexible electrochemical heavy metal sensor based on a gold (Au) electrode modified with layer-by-layer (LBL) assembly of titanium carbide (Ti₃C₂T_x) and multiwalled carbon nanotubes (MWNTs) nanocomposites was successfully fabricated for the detection of copper (Cu) and zinc (Zn) ions. An LBL drop-coating process was adopted to modify the surface of Au electrodes with Ti₃C₂T_x/MWNTs treated via ultrasonication to fabricate this novel nanocomposite electrode. In addition, an in situ simultaneous deposition of "green metal" antimony (Sb) and target analytes was performed to improve the detection performance further. The electrochemical measurement was realized using square wave anodic stripping voltammetry (SWASV). Moreover, the fabricated sensor exhibited excellent detection performance under the optimal experimental conditions. The detection limits for Cu and Zn are as low as 0.1 and 1.5 ppb, respectively. Furthermore, Cu and Zn ions were successfully detected in biofluids, that is, urine and sweat, in a wide range of concentration (urine Cu: 10-500 ppb; urine Zn: 200-600 ppb; sweat Cu: 300-1500 ppb; and sweat Zn: 500-1500 ppb). The fabricated flexible sensor also possesses other advantages of ultra-repeatability and excellent stability. Thus, these advantages provide a great possibility for the noninvasive smart monitoring of heavy metals in the future.

Assessment of copper, iron, zinc and manganese status and speciation in patients with Parkinson's disease: A pilot study

BACKGROUND

The objective of this pilot study was to assess iron (Fe), copper (Cu), zinc (Zn), and manganese (Mn) status (hair, serum, and urine) and speciation (serum) in Parkinson's disease (PD) patients.

METHODS

A pilot study involving a total of 27 subjects (13 PD patients, 14 controls) was performed. Serum, urine, and hair metal content was assessed using ICP-MS. Speciation analysis of Cu, Zn, Fe, and Mn was performed using a hybrid HPLC-ICP-MS system.

RESULTS

Group comparisons did not reveal any significant group difference in serum Cu, Zn, Fe, and Mn total metal level between PD patients and controls. Speciation analysis revealed a significant decrease in Cu/ceruloplasmin copper in association with elevation of low-molecular weight species (amino acids)-bound copper. It is proposed that in PD, binding of Cu(II) ions to ceruloplasmin is reduced and free copper ions coordinate with low molecular weight ligands. The level of Mn-albumin complexes in PD patients was more than 4-fold higher as compared to the respective value in the control group. The observed difference may be considered as a marker of redistribution between high and low molecular weight ligands.

CONCLUSIONS

Metal speciation is significantly affected in serum of PD-patients. These findings are indicative of the potential role of metal metabolism and PD pathogenesis, although the exact mechanisms of such associations require further detailed studies.

Association between Urinary Cadmium to Zinc Intake Ratio with Adult Mortality in a Follow-Up Study of NHANES 1988-1994 and 1999-2004

Cadmium (Cd) is a toxic heavy metal associated with increased mortality, but the effect of zinc (Zn) intake on the association between Cd and mortality is unknown. The objective of this study was to examine the association of urinary Cd to Zn intake ratio (Cd/Zn ratio) and mortality risk. In total, 15642 US adults in NHANES 1988-1994 and 1999-2004 were followed until 2011 (15-year mean follow-up). Of the 5367 total deaths, 1194 were attributed to cancer and 1677 were attributed to CVD. After adjustment for potential confounders, positive associations were observed between urinary Cd and all-cause mortality (HR for highest vs. lowest quartile: 1.38; 95% CI: 1.14-1.68) and cancer mortality (HR: 1.54; CI: 1.05-2.27). Urinary Cd was positively associated with cancer mortality among the lowest Zn consumers, and the association diminished among the highest Zn consumers. Positive relationships were observed between the Cd/Zn ratio and all-cause mortality (HR: 1.54; CI: 1.23-1.93), cancer mortality (HR: 1.65; CI: 1.11-2.47) and CVD mortality (HR: 1.49; CI: 1.18-1.88). In conclusion, these findings indicate that Zn intake may modify the association between Cd and mortality. Furthermore, the Cd/Zn ratio, which was positively associated with mortality from all causes, cancer, and CVD, may be an important predictor of mortality.

Serum and Urinary Selenium Status in Patients with the Pre-diabetes and Diabetes in Northeast China

Homeostasis imbalance of selenium (Se) in diabetes has received great attention. This study investigated serum and urinary Se levels in patients with impaired fasting glucose (IFG), impaired glucose tolerance (IGT), type 1 diabetes (T1D), and type 2 diabetes (T2D) in Northeast Chinese populations. From January 2010 to October 2011, patients with IFG (n = 12), IGT (n = 15), T1D (n = 25), T2D (n = 137), and healthy controls (n = 50) were enrolled in the First Hospital of Jilin University. Se was detected using inductively coupled plasma spectrometer. The serum Se level was dramatically lower in patients with T1D and was significantly higher in IFG subjects, and the urinary Se concentration was markedly lower in IGT and T2D groups. The serum Se levels were positively correlated with serum zinc (Zn) in both IFG and IGT groups, while urinary Se were positively associated with urinary Zn and copper (Cu) in IGT group. The serum Se levels were positively correlated with serum Cu in both T1D and T2D groups, and urinary levels of Se were positively associated with serum zinc and urinary Cu, Zn, calcium (Ca), and magnesium (Mg) and negatively correlated with serum Ca and Mg in T2D group, while the urinary levels of Se were positively correlated with urinary Zn and Mg both in peripheral neuropathy (DPN) and retinopathy (DR) groups. One month of simvastatin therapy reduced serum Se levels. These results suggest the potential role of Se in diabetes should receive attention.

Urinary concentrations of environmental metals and associating factors in pregnant women

Pregnant women, a vulnerable population, can be exposed to a variety of environmental metals that may adversely affect their health at elevated concentrations. Moreover, environmental exposure and risk disparities are associated with several factors such as sociodemographic characteristics, pregnancy complications, and nutritional supplementation indicators. Our aim was to investigate whether and how the urinary metal concentrations vary according to these factors in a large pregnancy and birth cohort. Urinary levels of seven metals including manganese, zinc, selenium, arsenic, cadmium, thallium, and lead were assessed in 7359 participants across Wuhan City in China. In all, 7359 urine samples from the third trimester were analyzed and 15 sociodemographic characteristics, pregnancy complications, and nutritional supplementation indicators were assessed: maternal age, household income, multivitamin supplements during pregnancy, etc. Concentrations of Zn, As, and Cd were detected in all urine samples; Mn, Se, Tl, and Pb were detected in 95.3%, 99.8%, 99.8%, and 99.9% urine samples, respectively. The geometric mean (GM) of creatinine-adjusted urinary Mn, Zn, Se, As, Cd, Tl, and Pb concentrations were 1.42, 505.44, 18.24, 30.49, 0.64, 0.55, and 3.69 μg/g. Factors that associated with environmental metals concentration were as follows: (1) Urinary Zn and Cd concentrations increased with maternal age. (2) Pregnant women with higher education had lower Cd concentrations. (3) Pregnant women with folic acid supplementation had lower Mn and with multivitamin supplementation had higher Se and lower Tl. Our results demonstrated that the maternal age, education level, folic acid supplementation, and multivitamin supplementation were significantly associated with environmental metal concentrations. Furthermore, studies are recommended to explore the influence of diet on biological metals concentrations in more detail.

Metal Biomonitoring and Comparative Assessment in Urine of Workers in Lead-Zinc and Steel-Iron Mining and Smelting

The exposure of heavy metals (lead (Pb), cadmium (Cd), copper (Cu), nickel (Ni), and metalloid arsenicals) and their effects on workers' health from a lead-zinc mine (145 workers) and a steel smelting plant (162 workers) was investigated. Information on subject characteristics was obtained through a questionnaire. We determined the urinary levels of Pb, Cd, Cu, Ni, and arsenicals (including inorganic arsenic (iAs), monomethylarsonic acid (MMA), and dimethylarsinic acid (DMA), as were 8-hydroxydeoxyguanosine (8-OHdG) and cystatin C. Lead-zinc mine foundry workers had significantly higher concentrations of urinary Pb, Cd, Cu, Ni, iAs, and MMA than did steel smelting plant workers. Individuals who had consumed seafood in the previous 3 days had higher concentrations of urinary Ni than did individuals who had not consumed seafood. The urinary Cd concentrations in the two groups of factory workers may have been affected by daily smoking. There was no significant difference in urinary 8-OHdG between workers from the lead-zinc mine foundry and the steel smelting plant. Urinary Pb and Cd had significant positive linear dose-dependent effects on 8-OHdG. Urinary cystatin C, a sensitive biological indicator reflecting early renal damage, was found at higher levels in lead-zinc mine workers than in steel smelting plant workers. Binary logistic regression analysis showed that age and urinary Cd were significantly associated with urinary cystatin C. These results indicated that workers from lead-zinc mines may be exposed to higher levels of heavy metals which could lead to greater risk of kidney damage.

Beneficial effect of polaprezinc on cardiac function post-myocardial infarction: A prospective and randomized clinical trial

BACKGROUND

Polaprezinc is clinically used for the treatment of gastric ulcers. It induces the mobilization of mesenchymal stem cells and the mRNA expression of insulin-like growth factor-1 in vascular endothelial cells in order to protect injured gastric tissue or skin.

METHODS

The current study population included 50 patients with primary acute myocardial infarction (AMI). After percutaneous coronary intervention, the subjects were randomly divided into 2 groups, namely, the nonpolaprezinc and polaprezinc groups. Peripheral blood and urinary samples were collected in a specific time to analyze zinc concentration, cardiac enzymes, and the levels of the inflammation marker interleukin-6. To evaluate the cardiac function, echocardiography was performed upon admission to the hospital and at 9 months post-AMI.

RESULTS

The urine and blood zinc levels of the polaprezinc group were higher compared with those of the non-polaprezinc group at 8 days after percutaneous coronary intervention. The mean interleukin-6/maximal creatine phosphokinase level was significantly reduced in the polaprezinc group (0.024 [0.003-0.066] vs. 0.076 [0.015-0.212], respectively; P = .045). In addition, echocardiography revealed that the ejection fraction of the nonpolaprezinc group was not significantly increased between day 3 and 9 months post-AMI (53 [49-60.8] vs. 59.5 [52-69.3], respectively; P = .015). However, a significant increase was detected in the ejection fraction of the polaprezinc group at the 2 time points (54 [51-57] vs. 62 [55-71], respectively; P < .01).

CONCLUSIONS

The results of the present study suggest that polaprezinc has an anti-inflammatory effect and improves cardiac function after AMI.

Influence of an Acute Exercise Until Exhaustion on Serum and Urinary Concentrations of Molybdenum, Selenium, and Zinc in Athletes

The aim of the present study was to determine changes occurring in serum and urine concentrations of essential trace elements with proven essentiality (molybdenum, selenium, and zinc) as a result of performing an acute physical activity until exhaustion in middle- and long-distance runners who live in the same area of Extremadura (Spain). Twenty-one Spanish national middle- and long-distance runners and 26 sedentary students of a similar age were recruited for the study. Both groups ran on a treadmill until exhaustion, starting at a speed of 10 and 8 km/h, respectively, and increasing the speed at 1 km/h every 400 m, without modifying the slope, always within the recommended parameters. Serum and urine samples were obtained from all subjects before and after the tests. Analysis of trace metals was performed by inductively coupled plasma mass spectrometry (ICP-MS). Resting serum and urinary concentrations between groups were compared using the Student t test, and the Wilcoxon test was used to analyze the trends of changes before and after the effort. The results showed that molybdenum concentrations were significantly higher in athletes than in controls (p < 0.01). Selenium (p < 0.05) and zinc (p < 0.01) concentrations were significantly lower in athletes than in controls. When we compared the serum concentrations before and after the test in the controls, only in the case of selenium (p = 0.006), a significant increase was observed after the test. However, this signification disappears with the corrections for hematocrit. Athletes' serum concentrations of Se (p = 0.004) and Zn (p = 0.005) lowered at the end of the test. Also, the results showed that there were no statistical urinary concentration (expressed in μg/g creatinine) changes in Mo and Se. Zn urinary concentration increased at the end of exercise (p = 0.018), since an incremental exercise to exhaustion in middle- and long-distance elite athletes produces a decrease in Se and Zn serum concentrations but Zn urinary concentration increased. In conclusion, athletes show higher serum concentrations of molybdenum and lower serum concentrations of selenium and zinc than sedentary subjects. Additionally, a treadmill test until exhaustion provokes a decrease in serum concentration of selenium and zinc and a higher excretion of urinary zinc. Serum concentrations of Se and Zn should be carried out in order to avoid any possible deficit cases and to establish the optimal supplementation.

The Association Between Renal Tubular Dysfunction and Zinc Level in a Chinese Population Environmentally Exposed to Cadmium

Studies in vivo and in vitro have shown a protective effect of zinc against renal dysfunction caused by cadmium exposure. However, limited human data is available. In this study, we evaluated the association between renal tubular dysfunction and body zinc burden in a Chinese population exposed to cadmium. A total of 331 subjects (170 women and 161 men) living in control and cadmium-polluted area were included. Blood cadmium (BCd), urinary cadmium (UCd), serum zinc (SZn), zinc in hair (HZn), Zn/Cd ratio, and urinary β₂Microglobulin (UBMG) were measured. The median UCd, BCd, SZn, and HZn were 2.8 and 13.6 μg/g cr, 1.3 and 12.2 μg/L, 1.31 and 1.12 mg/L, and 0.14 and 0.12 mg/g in subjects living in control and polluted areas. The UBMG level of subjects living in the polluted area was significantly higher than that of the control (0.27 vs 0.11 mg/g cr, p < 0.01). SZn, HZn, and Zn/Cd ratios were negatively correlated with UBMG (p < 0.05 or 0.01). Subjects with high SZn concentrations (≥ 1.62 mg/L) had reduced risks of elevated UBMG [(odds ratio (OR) = 0.26, 95% confidence interval (CI) 0.07-0.99)] after controlling for multiple covariates compared with those with lower zinc levels. A similar result was observed in subjects with high HZn (OR = 0.09, 95% CI 0.02-0.48). The ORs of the second, third, and fourth quartiles of Zn/Cd ratio were 0.40 (95% CI 0.19-0.84), 0.14 (95% CI 0.06-0.37), and 0.01 (95% CI 0.02-0.18) for renal dysfunction compared with those of the first quartile, respectively. For those subjects with high level of UCd, high level of SZn and HZn also had reduced risks of elevated UBMG. The results of the present study show that high zinc body burden is associated with a decrease risk of renal tubular dysfunction induced by cadmium. Zinc nutritional status should be considered in evaluating cadmium-induced renal damage.

A short 18 items food frequency questionnaire biochemically validated to estimate zinc status in humans

Inadequate dietary zinc intake is wide-spread in the world's population. Despite the clinical significance of zinc deficiency there is no established method or biomarker to reliably evaluate the zinc status. The aim of our study was to develop a biochemically validated questionnaire as a clinically useful tool that can predict the risk of an individual being zinc deficient. From 71 subjects aged 18-55 years blood and urine samples were collected. Zinc concentrations in serum and urine were determined by atomic absorption spectrometry. A food frequency questionnaire (FFQ) including 38 items was filled out representing the consumption during the last 6 months obtaining nutrient diet scores. Latter were calculated by multiplication of the particular frequency of consumption, the nutrient intake of the respective portion size and the extent of the consumed quantity. Results from the FFQ were compared with nutrient intake information gathered in 24-h dietary recalls. A hemogram was performed and cytokine concentrations were obtained using Enzyme-linked Immunosorbent Assay. Reducing the items of the primary FFQ from 38 to 18 did not result in a significant variance between both calculated scores. Zinc diet scores showed highly significant correlation with serum zinc (r = 0.37; p < 0.01) and urine zinc concentrations (r = 0.34; p < 0.01). Serum zinc concentrations and zinc diet scores showed a significant positive correlation with animal protein intake (r = 0.37; p < 0.01/r = 0.54; p < 0.0001). Higher zinc diet scores were found in omnivores compared to vegetarians (213.5 vs. 111.9; p < 0.0001). The 18 items FFQ seems to be a sufficient tool to provide a good estimation of the zinc status. Moreover, shortening of the questionnaire to 18 items without a loss of predictive efficiency enables a facilitated and resource-saving routine use. A validation of the questionnaire in other cohorts could enable the progression towards clinical utilization of this promising tool.

Effect of tramadol addiction alone and its co-abuse with cannabis on urinary excretion of Copper, Zinc, and Calcium among Egyptian addicts

BACKGROUND

The use of illicit drugs has become a worldwide health problem. Substances with the potential to be abused may have direct or indirect effects on physiologic mechanisms that lead to organ system dysfunction and diseases.

OBJECTIVE

The present study aims to investigate the structural and reabsorption integrity of the nephron among Egyptian addicts of tramadol alone and coabused with cannabis.

METHODS

Sixty-five males were included in the study, they were classified into control group (G1=19), tramadol addicts group (G2=18), and tramadol coabused with cannabis addicts group (G3=28). Parameters investigated for structural integrity were urinary levels ofleucineaminopeptidase and N-acetyl-β-D-glucosaminidase, and urinary parameters for reabsorption integrity were levels of copper and zinc as well as calcium, also urinary creatinine was measured. In addition, urinary levels of tramadol and tetrahydrocannabinol were estimated.

RESULTS

Among the two addicted groups, all measured parameters were not significantly different in comparison with the control group except for urinary calcium excretion which was found to be significantly increased among the two addicted groups.

CONCLUSION

Both tramadol addiction alone or coabused with cannabis causes increased urinary excretion of calcium, indicating reabsorption dysfunction of calcium without affecting structural integrity along the nephron.

The Divalent Elements Changes in Early Stages of Chronic Kidney Disease

As the glomerular filtration rate (GFR) decreases, it can cause imbalance in some divalent elements. These imbalances can cause increased oxidative stress in patients with renal impairment. The aim of present study was to investigate the changes of these divalent elements with CKD progression. One hundred and ninety-four patients with chronic kidney diseases (CKD) were divided into five stages, stage 1, 2, 3a, 3b, 4, and were recruited into this study. The divalent elements, calcium, magnesium, phosphorus, as well as iron, zinc, and copper were determined in clinical chemistry analyzer. Higher CKD stages were found to be associated with increased levels of phosphorus and copper; P_trend values were 0.002 and 0.004, respectively. Also, higher CKD stages were associated with decreased levels of zinc; P_trend value was 0.002, after adjustment for age, gender, smoke, education, diabetes, hypertension, and BMI. Decreased levels of zinc and elevated levels of phosphorus and copper might increase the oxidative stress and complications in CKD patients. Future randomized studies are needed to show whether adjusting dietary intake of phosphorus, copper, and zinc might affect the progression of CKD.

Prenatal Exposure to Aluminum and Status of Selected Essential Trace Elements in Rural South African Women at Delivery

This study sought to evaluate the in utero exposure to aluminum and status of selected trace elements in South African women at delivery since aluminum is known to be toxic in all developmental stages even at low concentrations. Serum aluminum was negatively correlated with aluminum in urine, both uncorrected and corrected for creatinine, which suggests the retention of aluminum in body stores. Serum copper and zinc levels were found to be high in this study population. Serum copper levels were negatively correlated with aluminum in serum (β = -0.095; p = 0.05). There was a marginal negative correlation between aluminum levels in serum and manganese levels in whole blood (β = -0.087; p = 0.08). Copper levels in maternal serum were negatively correlated with birth weight and the length of neonates. There were a number of positive correlations between maternal characteristics and birth outcomes. Mothers who consumed root vegetables frequently appeared to be protected from aluminum retention and increased body burden since their serum aluminum levels were found to be significantly lower. The findings of the current study can be used as a baseline for further research on aluminum exposure and its associated interactions and outcomes in vulnerable populations.

Effect of hypotensive therapy combined with modified diet or zinc supplementation on biochemical parameters and mineral status in hypertensive patients

BACKGROUND

Hypotensive therapy leads to a number of trace elements metabolism disturbances. Zinc balance is frequently affected by antihypertensive treatment.

AIM

To evaluate the effect of a hypotensive treatment, modified diet and zinc supplementation on mineral status and selected biochemical parameters in newly diagnosed hypertensive patients on monotherapy.

METHODS

In the first stage, arterial hypertension in ninety-eight human subjects was diagnosed. In the second stage, antihypertensive monopharmacotherapy was implemented. In the third stage, patients were randomized into three groups and continued antihypertensive monotherapy: group D received an optimal-mineral-content diet, group S received zinc supplementation, and group C had no changes in diet or zinc supplementation. Iron, zinc, and copper concentrations in serum, erythrocytes, urine, and hair were determined. Lipids, glucose, ceruloplasmin, ferritin, albumin, C-reactive protein (CRP), tumor necrosis factor α (TNF-α), nitric oxide (NO), superoxide dismutase (SOD) and catalase (CAT) were assayed in serum.

RESULTS

Antihypertensive monotherapy decreased zinc concentration in serum and erythrocytes and increased the level of zinc in urine, decreased CAT and SOD activity, TNF-α concentration in serum, and increased the level of NO in the serum. Zinc supply led to an increase in zinc concentration in serum, erythrocytes, and hair (in group S only). In the groups with higher zinc intake, decreased glucose concentration in the serum was observed. Significant correlation was seen between the zinc and glucose serum concentrations.

CONCLUSION

Hypotensive drugs disturb zinc status in newly diagnosed hypertensive patients. Antihypertensive monotherapy combined with increased zinc supply in the diet or supplementation favorably modify zinc homeostasis and regulate glucose status without blood pressure affecting in patients with hypertension.

Chronic exposure to low-level cadmium induced zinc-copper dysregulation

BACKGROUND AND OBJECTIVES

Exposure to cadmium (Cd) has been associated with aberrant zinc and copper homeostasis. This study investigated if Cd exposure impairs renal reabsorption of metals.

METHODS

Renal tubular reabsorption of metals were calculated from urine to serum metal ratios and analyzed for an independent association with Cd exposure levels, using data from 100 men and 100 women, aged 16-60 years.

RESULTS

The smoking prevalence was 30% in men and 0% in women. The male and female means (SD) for urine Cd were 0.54 (0.43) and 0.62 (0.43) μg/g creatinine. The mean (SD) for fractional zinc reabsorption was 77.2 (23) % in men and 87.7 (13.3) % in women, while the copper reabsorption was 100% in both men and women. Lower zinc reabsorption levels were associated with higher Cd exposure (P<0.001), higher serum copper to zinc ratios (P=0.007) and higher tubular impairment levels (P=0.024). Reduced zinc reabsorption was particularly severe in smokers as those with high Cd exposure had 44.9% and 37.2% (P<0.001) lower zinc reabsorption than those with low and moderate exposures. The mean zinc reabsorption in male non-smokers with high Cd exposure was 25.8% (P<0.001) and 18.2% (P=0.003) lower than those with low and moderate exposures, while the corresponding figure for female non-smokers was 17% (P<0.001), and 12.8% (P=0.013), respectively.

CONCLUSIONS

This is the first report demonstrating Cd-dose dependent reduction in renal zinc reabsorption and high serum copper to zinc ratios.

Effect of an Extract from Aronia melanocarpa L. Berries on the Body Status of Zinc and Copper under Chronic Exposure to Cadmium: An In Vivo Experimental Study

In an experimental model of low-level and moderate environmental human exposure to cadmium (Cd), it was investigated whether the consumption of a polyphenol-rich Aronia melanocarpa L. berries (chokeberries) extract (AE) may influence the body status of zinc (Zn) and copper (Cu). The bioelements' apparent absorption, body retention, serum and tissue concentrations, total pool in internal organs, excretion, and the degree of binding to metallothionein were evaluated in female rats administered 0.1% aqueous AE or/and Cd in their diet (1 and 5 mg/kg) for 3-24 months. The consumption of AE alone had no influence on the body status of Zn and Cu. The extract administration at both levels of Cd treatment significantly (completely or partially) protected against most of the changes in the metabolism of Zn and Cu caused by this xenobiotic; however, it increased or decreased some of the Cd-unchanged indices of their body status. Based on the findings, it seems that rational amounts of chokeberry products may be included in the daily diet without the risk of destroying Zn and Cu metabolisms; however, their potential prophylactic use under exposure to Cd needs further study to exclude any unfavourable impact of these essential elements on the metabolism.

Comparison of sodium, potassium, calcium, magnesium, zinc, copper and iron concentrations of elements in 24-h urine and spot urine in hypertensive patients with healthy renal function

Sodium, potassium, calcium, magnesium, zinc, copper and iron are associated with the sequela of hypertension. The most reliable method for testing those elements is by collecting 24-h urine samples. However, this is cumbersome and collection of spot urine is more convenient in some circumstance. The aim of this study was to compare the concentrations of different elements in 24-h urine and spot urine.

METHODS

Data was collected from a sub-study of China Salt Substitute and Stroke Study. 240 participants were recruited randomly from 12 villages in two counties in Ningxia, China. Both spot and 24-h urine specimens were collected from each patient. Routine urine test was conducted, and concentration of elements was measured using microwave digestion and Inductively Coupled Plasma-Optical Emission Spectrometry. Partial correlation analysis and Spearman correlation analysis were used to investigate the concentration of different elements and the relationship between 24- h urine and spot urine.

RESULTS

A partial correlation in sodium, potassium, calcium, magnesium and iron was found between paired 24-h urine and spot urine samples except copper and zinc: 0.430, 0.426, 0.550, 0.221 and 0.191 respectively.

CONCLUSIONS

Spot urine can replace 24-h urine for estimating some of the elements in hypertensive patients with normal renal function.

Synthesis and characterization of new 1-hydroxy-2-pyridinethione derivatives: Their lead complexes and efficacy in the treatment of acute lead poisoning in rats

A number of new mono- and dihydroxypyridinethione ligands have been synthesized via reaction of dimethylamine and amino acid esters with the active amide obtained from the reaction of 1-hydroxy-2-pyridinethione-4-carboxylic acid (1) and 1,1'-carbonyldiimidazole in DMF. Moreover, the lead complexes of these new ligands were also prepared. Structures of the newly synthesized compounds have been confirmed by different spectroscopic methods such as IR, ¹H NMR, and ¹³C NMR, and by elemental analysis. The effect of these synthesized ligands on the excretion of lead, iron, and zinc, and their distribution in kidneys, liver, and bones in acutely intoxicated rats was investigated and results, for lead, were compared with those of the known drug meso-2,3-dimercaptosuccinic acid (DMSA). Results obtained revealed that compound 5 exhibits remarkable ability in total fecal and urinary excretion of lead and was superior to DMSA. In addition, results show that the concentration of lead in soft tissues and bones was lower in rats treated with HTPL than those treated with DMSA. Furthermore, the concentration of lead in liver tissues obtained from sub-chronic lead-intoxicated rats treated with HTPL was lower than those treated with DMSA and calcium disodium ethylenediaminetetraacetic acid (CaNa₂EDTA).

Dose-response analysis of environmental exposure to multiple metals and their joint effects with fasting plasma glucose among occupational workers

OBJECTIVES

Environmental exposure to metals may adversely affect cardiometabolic health. However, little data are available directly evaluating the roles of metal exposure in blood glucose of which dysfunction has been linked to diabetes. We aimed to evaluate the dose-response associations between fasting plasma glucose (FPG) and multiple urinary metals including nickel, cobalt, copper, zinc, and arsenic, as well as to examine their joint effects among occupational workers.

METHODS

We performed a population-based study of 464 workers in an ongoing occupational cohort study in China. Both spline and categorical analyses were used to evaluate the dose-response relationship between urinary metals levels and FPG.

RESULTS

We observed the J-shaped non-linear relationships between urinary nickel (P non-linearity = 0.03) and zinc (P non-linearity < 0.01) with FPG by spline analyses. A negative linear relationship between urinary cobalt and FPG (P for nonlinearity = 0.06) was found, but no statistically significant associations between urinary copper and arsenic with FPG. In linear regression analyses, the regression coefficient for log-transferred FPG was 0.017 (95% confidence intervals [CI]: -0.003, 0.038) in the 4th quartile concentration of urinary nickel, compared with 1st quartile. The joint effects between urinary nickel and cobalt with FPG were also detected (P for interaction = 0.04).

CONCLUSIONS

Multiple urinary metals, particularly nickel, zinc and cobalt, were associated with blood glucose among Chinese metal exposed workers, supporting the notion that metal exposure may play a critical role in diabetes development.

Concentration of Zinc, Copper, Iron, Calcium, and Magnesium in the Serum, Tissues, and Urine of Streptozotocin-Induced Mild Diabetic Rat Model

The present study aimed to investigate, in the streptozotocin-induced mild diabetic rat model, the zinc (Zn), copper (Cu), iron (Fe), calcium (Ca), and magnesium (Mg) concentration in serum, liver, and kidney tissues, and urine samples from adult Wistar rats treated neonatally with streptozotocin (STZ). Diabetes was induced by subcutaneous administration of streptozotocin (100 mg/Kg) in female Wistar rats of 2 days old (STZ, n = 10). Control group (CG, n = 10) received only sodium-citrate buffer. The mineral concentrations were measured by atomic absorption spectrophotometry. The validity and accuracy were checked by conventional methods. STZ neonatal injection successfully leaded to mild diabetes in the adult rats. Serum concentrations of Zn, Cu, Fe, Ca, and Mg showed no changes (p > 0.05) due to diabetes. The Zn, Fe, Ca, and Mg concentrations in liver and kidney tissues were not different (p > 0.05) between STZ and CG. The mean values of Cu were higher (p < 0.05) in liver and kidney samples from STZ as compared to CG. Urine minerals concentrations (Zn, Cu, Fe and Ca) in STZ-rats group were lower (p < 0.05) than CG. However, the content of all evaluated minerals in the excreted urine were higher (p < 0.01) in STZ-rats during a 24 h collection period. Urinary excretion of Zn, Cu, Fe, Ca, and Mg was strongly correlated with urinary volume during the 24 h period (r > 0.7; p < 0.001). Observed changes in mineral metabolism of STZ-induced mild diabetes model could be due to the endocrine imbalance associated with the diabetic condition.

Comparative study of CTX-II, Zn2+, and Ca2+ from the urine for knee osteoarthritis patients and healthy individuals

The aim of the study was to explore the relationship between the concentration of C-telopeptide fragments of type II collagen (CTX-II), Zn, and Ca in urine and knee osteoarthritis (KOA).Eighty-two patients with KOA and 20 healthy volunteers were enrolled. Anteroposterior and lateral position x-rays of knee joints were collected. The images were classified according to Kellgren-Lawrence radiographic grading criterion. The patients were divided into group grade I, group grade II, group grade III, and grade IV. The concentration of CTX-II in the urine was detected by enzyme-linked immunosorbent assay. The concentration of Zn and Ca in urine was detected by inductively coupled plasma atomic emission spectrometry.Compared with the healthy individuals, the concentration of CTX-II was significantly higher in KOA patients. The concentration of CTX-II in KOA patients from high to low was as follows: group IV, group III, group II, and group I. There was no significant difference between group I and healthy individuals. The concentration of Zn and Ca in urine of KOA patients was higher than that in healthy individuals. There was no difference in each KOA group.The concentration of CTX-II is instrumental to diagnose the progress of KOA. The concentration of Zn and Ca in urine is helpful for early diagnosis of KOA.

Dietary Zinc Supplementation Attenuates Hyperglycemia in db/db Mice

Although zinc (Zn) deficiency has been associated with insulin resistance, and altered Zn metabolism (e.g., hyperzincuria, low-normal plasma Zn concentrations) may be present in diabetes, the potential effects of Zn on modulation of insulin action in Type II diabetes have not been established. The objective of this study was to compare the effects of dietary Zn deficiency and Zn supplementation on glycemic control in db/db mice. Weanling db/db mice and lean littermate controls were fed Zn-deficient (3 ppm Zn; dbZD and InZD groups), Zn-adequate control (30 ppm Zn; dbC and InC groups) or Zn-supplemented (300 ppm Zn; dbZS and InZS groups) diets for 6 weeks. Mice were assessed for Zn status, serum and urinary indices of diabetes, and gastrocnemius insulin receptor concentration and tyrosine kinase activity. Fasting serum glucose concentrations were significantly lower in the dbZS group compared with the dbZD group (19.3 ± 2.9 and 27.9 ± 4.1 mM, respectively), whereas the dbC mice had an intermediate value. There was a negative correlation between femur Zn and serum glucose concentrations (r = −0.59 for lean mice, P = 0.007). The dbZS group had higher pancreatic Zn and lower circulating insulin concentrations than dbZC mice. Insulin-stimulated tyrosine kinase activity in gastrocnemius muscle was higher in the db/db genotype, and insulin receptor concentration was not altered. In summary, dietary Zn supplementation attenuated hyperglycemia and hyperinsulinemia in db/db mice, suggesting that the roles of Zn in pancreatic function and peripheral tissue glucose uptake need to be further investigated.

Effect of mercury vapour exposure on urinary excretion of calcium, zinc and copper: relationship to alterations in functional and structural integrity of the kidney

Background: The kidney has a remarkable capacity to concentrate mercury (Hg) and as such is a primary target organ when exposure to Hg occurs, and it is also an organ for Hg excretion. Objective: The present work aims to investigate the effect of occupational Hg vapour exposure on the urinary excretion of calcium (Ca), zinc (Zn) and copper (Cu), and the possible association of this excretion to work duration as well as renal alterations. Methods: 83 non-smoker participants (36 referents, age: 35.69/9.5 years; 27 Hg vapour-exposed workers with 5/10 years work duration, age: 33.09/5.1 years; and 20 Hg vapour-exposed workers with]/11 years work duration, age: 39.509/8.50 years) were included in the present study. Urinary levels of microalbumin (U-Malb) and retinol-binding protein (U-RBP) as well as cytosolic glutathione S-transferase activity (U-GST) were measured to assess the glomerular and proximal tubular reabsorption functions as well as structural integrity of proximal tubules; respectively. In addition, blood Hg (B-Hg), serum levels of Hg (S-Hg) and Ca (S-Ca), and urinary levels of Hg (U-Hg), Ca (U-Ca), Zn (U-Zn), Cu (U-Cu) and creatinine (U-cr) were estimated. Results: In comparison to referents, all investigated parameters showed significant increase (except S-Ca and U-Zn/U-Cu ratio that significantly decreased among the workers as one group, S-Ca and U-Zn/U-Cu ratio that significantly and nonsignificantly decreased; respectively among workers with 5/10 years work duration, S-Ca and U-Zn/U-Cu ratio that significantly decreased among workers with]/11 years work duration). In addition, B-Hg was nonsignificantly increased and S-Ca was significantly decreased; also, both U-Hg and U-Zn/U-Cu were nonsignificantly decreased among workers with]/11 years work duration in comparison to those with 5/10 years work duration. Also, each of U-Hg, U-Ca, U-Zn and U-Cu was related to one another, while each of U-Ca, U-Zn and U-Cu was related to each of U-Malb, U-RBP and U-GST (except U-Zn was not related to U-GST). Conclusion: Hg vapour exposure leads to renal alterations which may parallel the change in proteinuria and enzymuria as well as the increased loss in urine of each of Ca, Zn and Cu. The urinary assessment of these metals may be used as a good indicator for renal dysfunction.

The effect of zinc supplementation on the urinary excretion of elements in female athletes

This study was carried out to find out how oral zinc supplementation to elite athletes affects the element changes in the urine. The study registered 10 female athletes who were on the women's volleyball team of Gazi University Sports Club and whose mean age, weight, and height were 14.2±0.42 years, 59.8±7.79kg and 173.6±6.15 cm. The study protocol was approved by the local ethics committee. The athletes who continued their daily routine training sessions (6 days/week) were supplemented with 220mg/day oral zinc sulfate for 4 weeks. In order to induce exhaustion, the subjects were put to a 20-meter shuttle run test before and after supplementation. A total, 7 times urine samples were collected follows as pre and post exercise before the start of the experiment and at the end (4 times), at the end of first, second and third week (3 times). Urinary levels of magnesium, phosphorus, and calcium (mg/dl), as well as zinc, copper, and selenium (μg/dl) were analyzed in the atomic emission device (ICP-MS). Arithmetic means and standard errors of the data were calculated. Kruskal Wallis test was used to determine differences between weeks. Values for which p<0,05 were considered significant. When compared to resting values, urinary excretion of copper and selenium decreased in exercise (p<0,05), but increased with zinc supplementation (p<0,05). Pre- and post-supplementation exercise resulted in reduced urinary zinc excretion (p<0,05). Zinc supplementation increased urinary zinc excretion in one-week intervals over the course of 4 weeks (p<0,05), and reduced selenium levels (p<0,05). When zinc is supplemented to athletes, the relation between the duration and dose of supplementation is important. The results of the study indicated that zinc does not have any negative effect on the urinary excretion of the concerned elements. It can thus be concluded that athletes may benefit from zinc support.

Genetic variation in metallothionein and metal-regulatory transcription factor 1 in relation to urinary cadmium, copper, and zinc

BACKGROUND

Metallothionein (MT) proteins play critical roles in the physiological handling of both essential (Cu and Zn) and toxic (Cd) metals. MT expression is regulated by metal-regulatory transcription factor 1 (MTF1). Hence, genetic variation in the MT gene family and MTF1 might influence excretion of these metals.

METHODS

321 women were recruited in Seattle, WA and Las Cruces, NM and provided demographic information, urine samples for measurement of metal concentrations by mass spectrometry and creatinine, and blood or saliva for extraction of DNA. Forty-one single nucleotide polymorphisms (SNPs) within the MTF1 gene region and the region of chromosome 16 encoding the MT gene family were selected for genotyping in addition to an ancestry informative marker panel. Linear regression was used to estimate the association of SNPs with urinary Cd, Cu, and Zn, adjusted for age, urinary creatinine, smoking history, study site, and ancestry.

RESULTS

Minor alleles of rs28366003 and rs10636 near the MT2A gene were associated with lower urinary Cd, Cu, and Zn. Minor alleles of rs8044719 and rs1599823, near MT1A and MT1B, were associated with lower urinary Cd and Zn, respectively. Minor alleles of rs4653329 in MTF1 were associated with lower urinary Cd.

CONCLUSIONS

These results suggest that genetic variation in the MT gene region and MTF1 influences urinary Cd, Cu, and Zn excretion.

Autosomal-Recessive Intellectual Disability with Cerebellar Atrophy Syndrome Caused by Mutation of the Manganese and Zinc Transporter Gene SLC39A8

Manganese (Mn) and zinc (Zn) are essential divalent cations used by cells as protein cofactors; various human studies and animal models have demonstrated the importance of Mn and Zn for development. Here we describe an autosomal-recessive disorder in six individuals from the Hutterite community and in an unrelated Egyptian sibpair; the disorder is characterized by intellectual disability, developmental delay, hypotonia, strabismus, cerebellar atrophy, and variable short stature. Exome sequencing in one affected Hutterite individual and the Egyptian family identified the same homozygous variant, c.112G>C (p.Gly38Arg), affecting a conserved residue of SLC39A8. The affected Hutterite and Egyptian individuals did not share an extended common haplotype, suggesting that the mutation arose independently. SLC39A8 is a member of the solute carrier gene family known to import Mn, Zn, and other divalent cations across the plasma membrane. Evaluation of these two metal ions in the affected individuals revealed variably low levels of Mn and Zn in blood and elevated levels in urine, indicating renal wasting. Our findings identify a human Mn and Zn transporter deficiency syndrome linked to SLC39A8, providing insight into the roles of Mn and Zn homeostasis in human health and development.

Zinc Absorption from Fortified Milk Powder in Adolescent Girls

Zinc (Zn) is essential for development, growth, and reproduction. The Mexican government subsidizes micronutrient-fortified milk for risk groups, with positive effect on the targeted groups' plasma Zn level, inferring a good absorption is achieved although it has not being measured. The aim of this study was to determine the impact of micronutrient-fortified milk intake during 27 days on Zn absorption in adolescent girls from northwest Mexico. Therefore, Zn absorption was evaluated in 14 healthy adolescent girls (14.1 years old) with adequate plasma Zn levels, before and after 27 days of fortified Zn milk intake. Fractional Zn absorption (FZA) was calculated from urinary ratios of stable isotopic Zn tracers administered orally and intravenously on days 0 and 27, and total absorbed Zn (TZA) was calculated. At the beginning, Zn intake was 6.8 ± 0.85 mg/d (mean ± SE), and 50 % of the adolescent girls did not achieve their requirement (7.3 mg/d). Additionally, FZA was negatively correlated with Zn intake (r =-0.61, p = 0.02), while TZA (1.06 mg/d) was insufficient to cover the physiologic requirements of adolescent girls (3.02 mg/d). At the end of the intervention, all the girls reached the Zn intake recommendation and TZA, 3.09 mg/d, which was enough to meet the physiological requirement for 57 % of the adolescent girls. Therefore, the low Zn intake and the Zn status of adolescent girls were positively impacted by Zn-fortified milk intake and its good absorption rate.

[Distribution of copper and zinc level in urine of general population in eight provinces of China]

OBJECTIVE

To describe the distribution of zinc (Zn) and copper (Cu) in urine samples of generalpopulation in eight provinces of China, to analyze their characteristics of distribution between different region, gender and age-cohorts, and to provide the baseline of themetabolites in the general population.

METHODS

From 2009 to 2010, 18 120 subjects from the general population aged from 6 to 60 years old were recruited from 24 areas among 8 provinces of China mainland by random sampling. The environmental and physical condition characteristics were collected from questionnaires, and urine samples were collected at the mean time. The levels of Zn and Cu in urine were measured using ICP-MS. Data were analyzed by statistical methods to compare the distribution characteristics of Zn and Cu among populations with different ages and genders.

RESULTS

Totally, the median of Cu and Zn in urine were 9.28 and 115.47 µg/L respectively; and the inter-quartile range of Cu and Zn were 2.66-16.09 and 35.32-265.15 µg/L respectively. The median of Cu in male and female were 9.90 and 8.60 µg/L (Z=-5.63, P<0.001), and Zn in male and female were 140.44 and 95.27 µg/L (Z=-14.79, P<0.001). The median of Cu among the groups aged 6-12, 13-16, 17-20, 21-30, 31-45 and 46-60 years old were 9.30, 10.14, 9.67, 9.33, 8.38 and 8.74 µg/L (χ2=70.94, P<0.001), respectively, and the median of Zn 130.83, 132.07, 139.34, 109.3, 78.74 and 109.51 µg/L ((χ2=146.00, P<0.001), respectively.There was statistically significant differences in urinary Cu and Zn levels between male and female, and among the different age groups.

CONCLUSION

The Cu and Zn levels and distribution in urine among general population between 2009 and 2010 in China were reported in this article. These basic data in China will provide scientific and reliable reference for further scientific research.

Interaction between essential elements selenium and zinc with cadmium and mercury in samples from hypertensive patients

The abnormal metabolism of metal ions plays an important role in health and disease conditions; hence, the studies about them have received much interest. The objective of this study was to evaluate the association between trace and toxic elements zinc (Zn), cadmium (Cd), selenium (Se), and mercury (Hg) in biological samples (scalp hair, blood, and urine) of hypertensive patients (n = 257), residents of Hyderabad, Pakistan. For comparison purpose, the biological samples of age-matched healthy controls were selected as referents. The concentrations of trace and toxic elements were measured by atomic absorption spectrophotometer prior to microwave-assisted acid digestion. The validity and accuracy of the methodology was checked using certified reference materials and by the conventional wet acid digestion method. The recovery of all studied elements was found in the range of 96.4-99.1 % in certified reference materials. The results of this study showed that the mean values of Cd and Hg were significantly higher in scalp hair, blood, and urine samples of hypertensive patients than in referents (P < 0.001), whilst the concentrations of Zn and Se were lower in the scalp hair and blood, but higher in the urine samples of hypertensive patients. The deficiency of Zn and Se and the high exposure of toxic metals may be synergistic with risk factors associated with hypertension.

BMI and levels of zinc, copper in hair, serum and urine of Turkish male patients with androgenetic alopecia

OBJECTIVE

Male pattern androgenetic alopecia is characterized by progressive hair loss from the scalp. It is known that imbalances of some trace elements play a role in the pathomechanism of many forms of alopecia. The aim of this study was to evaluate the levels of zinc and copper in hair, serum and urine samples of Turkish males with male pattern androgenetic alopecia and to compare with healthy controls.

MATERIAL AND METHODS

116 males with male pattern androgenetic alopecia and 100 controls were involved in this study.

RESULTS

Levels of zinc and copper in hair were decreased significantly in the patients (p<0.05), although zinc and copper levels of serum and urine were not different between patients and controls (p>0.05). Body mass index of patients were higher than control group. In addition, in the group with body mass index of 25 and lower zinc level in hair and urine, copper level in serum were significantly higher (p<0.05). Body mass index was negatively correlated with hair zinc levels.

CONCLUSION

We thought that decreased zinc and copper levels in hair may play a role in the etiology of male pattern androgenetic alopecia. In addition, obesity by making changes in the balance of the trace elements in hair, serum and urine may play a role in male pattern androgenetic alopecia. Hence, assessing the levels of trace elements in hair of male pattern androgenetic alopecia patients may be more valuable compared to serum and urine for treatment planning.

Effects of selenium on liver and muscle contents and urinary excretion of zinc, copper, iron and manganese

Selenium is a main component of glutathione peroxidase (GPX), a key antioxidant enzyme. Other elements, such as zinc, copper, manganese and iron, are also involved in the pathogenesis of oxidative damage as well as in other important metabolic pathways. The effects of selenium supplementation on the metabolism of these elements have yield controversial results .The aim of this study is to analyse the effects of selenium supplementation on liver, muscle and urinary excretion of zinc, copper, iron and manganese in a situation of oxidative stress, such as protein deficiency. The experimental design included four groups of adult male Sprague-Dawley rats, which received the Lieber-DeCarli control diet, an isocaloric 2 % protein-containing diet and another similar two groups to which selenomethionine (6 mg/l liquid diet) was added. After sacrifice (5 weeks later), muscle, liver and serum selenium were determined, as well as muscle, liver and urinary zinc, copper, manganese and iron and liver GPX activity and liver malondialdehyde. Selenium addition led to decreased liver copper, increased muscle copper, increased copper excretion and increased liver iron, whereas zinc and manganese parameters were essentially unaltered. Muscle, liver and serum selenium were all significantly correlated with liver GPX activity.

The alteration of zinc transporter gene expression is associated with inflammatory markers in obese women

Obesity, a chronic inflammatory state, is associated with altered zinc metabolism. ZnT and Zip transporters are involved in the regulation of zinc metabolism. This study examined the relationships among obesity, zinc transporter gene expression, and inflammatory markers in young Korean women. The messenger RNA (mRNA) levels of leukocyte zinc transporters between obese (BMI = 28.3 ± 0.5 kg/m(2), n = 35) and nonobese (BMI = 20.7 ± 0.2 kg/m(2), n = 20) women aged 18-28 years were examined using quantitative real-time polymerase chain reaction. Inflammatory markers, such as C-reactive protein (CRP), tumor necrosis factor-alpha (TNF-α), and interleukin (IL)-6, were measured in serum by enzyme immunoassay. ZnT1 and Zip1 were the most abundantly expressed zinc transporters in leukocytes. The mRNA levels of many zinc transporters (ZnT4, ZnT5, ZnT9, Zip1, Zip4, and Zip6) were significantly lower in obese women, and expression of these genes was inversely correlated with BMI and body fat percentage. In addition, inflammatory markers (CRP and TNF-α) were significantly higher in obese women. The mRNA levels of ZnT4, Zip1, and Zip6 were inversely correlated with CRP (P < 0.05), and mRNA levels of ZnT4 and ZnT5 were inversely correlated with TNF-α (P < 0.05). In standardized simple regression models, levels of TNF-α and CRP were negatively associated with mRNA levels of zinc transporters such as ZnT4, ZnT5, Zip1, and Zip6 (P < 0.05). These results suggest that the expression of zinc transporters may be altered in obese individuals. Changes in zinc transporters may also be related to the inflammatory state associated with obesity.

Zinc and copper changes in serum and urine after aerobic endurance and muscular strength exercise

AIM

The role of zinc and copper has been shown essential in the scope of physical exercise. The outcomes of the studies about changes in the concentrations of these elements in blood, in physical effort situations, are sometimes discordant and seem to be related with the type of the exercise done. The purpose of the study was to determine the changes of zinc and copper in serum and urine produced by two kinds of exercise, designing two tests involving different types of physical exertion, which have been defined as aerobic endurance (AE) and muscular strength (MS).

METHODS

The study was designed to assess the variations of both elements in two types of exercise: AE, participants: 22 subjects, consisted of run for 40 minutes with a heart rate intensity of ±5 beats per minute from the anaerobic threshold (AnT). MS, participants: 16 subjects, consisted of performing a circuit of 8 different exercises, applying 40% of maximum peak force, until exhaustion.

RESULTS

The serum concentration of Zn decreases in both exercises, being statistically significant in the MS (P<0.001). Cu concentration increases significantly in AE (P=0.002) as well as in MS (P<0.001). Urine concentrations of both elements increases after exercise in the two cases (P<0.05 in AE; P<0.001 in MS), the variation of Zn is correlated with proteinuria generated which appears after physical exertion (r=0.59).

CONCLUSION

Findings suggest that changes of Zn and Cu in serum and urine are related to the type of exercise performed, which are higher when there is a big impact on muscular tissues.

Effect of zinc supplementation on inflammatory markers and adipokines in young obese women

Obesity is a chronic inflammatory state characterized by altered adipokine production and increased levels of inflammatory cytokines. The study explored the effect of zinc supplementation on inflammatory markers and adipocyte hormones in young obese women. Twenty five non-obese women and forty obese women (body mass index ≥25 kg/m(2)) aged 19-28 years were recruited for this study. Twenty obese women of the study group took 30 mg/day of supplemental zinc as zinc gluconate for 8 weeks and 20 obese women of control group took placebo. Usual dietary zinc intake was estimated from 3-day diet records. Serum zinc and urinary zinc concentration were measured by Atomic Absorption Spectrophotometry. Inflammatory markers such as high sensitivity C-reactive protein (hs-CRP), tumor necrosis factor-alpha (TNF-α), and interleukin (IL)-6 and adipocyte hormones such as lepin and adiponectin were measured by enzyme immunoassay. Inflammatory markers and leptin were significantly higher, but adiponectin was significantly lower in obese women than non-obese women. Zinc supplementation increased serum zinc by 15% and urinary zinc by 56% (P < 0.05). The levels of hs-CRP (P = 0.03) and IL-6 (P = 0.006) significantly decreased with zinc supplementation, but not in placebo group. Serum leptin and plasma adiponectin concentration did not differ with either zinc supplementation or placebo. The levels of IL-6 and leptin were inversely associated with dietary zinc intake. These results suggest that zinc may have a favorable effect on obesity-related inflammation in young adults.

The influence of antihypertensive drugs on mineral status in hypertensive patients

OBJECTIVES

Long-term therapy of hypertension may influence mineral status in patients. However, drug-micronutrient interactions are largely unexplored in practice. This study intended to evaluate the effect of hypotensive monotherapy on iron, zinc, and copper levels, as well as on selected biochemical parameters, in newly diagnosed patients with hypertension, and to assess the influence of diet with optimal mineral levels on the mineral balance in these subjects.

PATIENTS AND METHODS

Forty-five patients, aged 18-65 years with diagnosed essential hypertension, beginning monotherapy treatment with diuretics, calcium antagonists, angiotensin-converting enzyme inhibitors, and β-blockers, were employed. Over three months, the patients underwent monotherapy (stage II). Next, patients were randomly divided into a diet group (of 27 subjects) and a control group (of 18 subjects). In this stage, which lasted one month, patients were given the same drug but also followed an optimal mineral-content diet (for the diet group), or else continued drug use without any change in diet (for control group) (stage III). Lipids, glucose, ceruloplasmin, and ferritin--along with superoxide dismutase and catalase activities--were assayed in serum. Iron, zinc, and copper concentrations in serum, erythrocytes, and urine were determined using flame atomic absorption spectrometry. Blood pressure was measured. Diet intake was monitored at each stage.

RESULTS

It was found that the zinc level in serum significantly decreased following treatment, and that the use of the optimal-mineral diet during antihypertensive treatment markedly increased zinc serum concentration. After treatment, a significant increase in zinc excretion in the urine was observed. Glucose levels in the serum of patients in stage II were significantly higher than in the baseline. In patients in the diet group, glucose levels markedly decreased. Moreover, a negative correlation was found between serum glucose and zinc levels in patients.

CONCLUSIONS

Antihypertensive treatments should include monitoring of mineral status. It seems that the zinc balance of patients on long-term therapy with hypotensive drugs may benefit from an optimal-mineral diet.

Dietary intervention causes redistribution of zinc in obese adolescents

Obese people tend to have low zinc circulation levels; this is not always related to zinc intake but can reflect the distribution of zinc in relation to the proportion of body fat and factors related to the inflammatory processes that cause obesity. The purpose of this study was to assess zinc distribution in 15 obese adolescent girls before and after a nutritional orientation program. Participants ranged from 14 to 18 years old (postpubescent) and had a body fat percent (BF%) of >35 %. Zinc nutritional status and other zinc-dependent parameters, such as superoxide dismutase (SOD) and insulin levels, were assessed by biochemical analysis of plasma and erythrocytes, salivary sediment, and urine. Samples were collected before and after 4 months of dietary intervention. Dual energy X-ray absorptiometry (DXA) was used to verify BF% both at the beginning and at the end of the study. Food consumption was assessed in ten individual food questionnaires throughout the study; food groups were separated on the questionnaires in the same way as suggested by some authors to develop the Healthy Eating Index (HEI) but with the addition of zinc. After 4 months of nutritional orientation, 78 % of the participants showed a decrease in BF%. Intraerythrocytic zinc increased over the study period, while salivary sediment zinc, SOD, insulin, and Zn urinary24 h/creatinine all decreased (p < 0.05). There was no difference in zinc intake throughout the study but participants did increase their consumption of fruits, dairy, and meats during the study (p < 0.05). There were inverse and statistically significant correlations between the increased levels of intraerythrocytic zinc and decreased levels of SOD. There was also a statistically significant correlation between BF% and Zn urinary 24h/creatinine, and SOD. All these parameters were diminished at the end of the study. The dietary intervention for obese adolescent girls is effective with decrease of BF that led to the redistribution of zinc in the body as shown by the changes in erythrocytes, plasma, salivary, urine zinc, as well as the complementary parameters of insulin and SOD. These changes were not affected by zinc intake.

[The ratio between basic microelements (Fe, Cu, Zn) under anemia of different etiology]

The homeostasis of basic microelements (Fe, Cu and Zn) is ultimately important for normal functioning of organism. The article presents the data concerning the detection of these metals both in blood serum and urine of patients with anemia of different etiology. The indicators of excretion can provide additional information for diagnostics and needed therapy. The article describes in details simple colorimetric methods of detection of mentioned metals in urine. It is demonstrated that under anemia the positive balance of cuprum is noted. This occurrence can be a possible cause of coagulation complications.

The effects of chelators on zinc levels in patients with thalassemia major

Zinc which is an essential element has very important effects on growth and immune system in patients with thalassemia major (TM). The effects of two oral iron chelator agents, desferrioxamine (DFO) and deferiprone (DFP), on zinc levels were investigated in previous studies and they were found to cause zinc deficiency. Zinc level alteration by the new chelator deferasirox (DFX) is not present in the literature. The aim of this study was to examine the effects of different oral chelators on serum and urine zinc levels in TM patients. Zinc levels are compared in the patients who received different chelators: only DFX, combined chelation with DFO plus DFP and the healthy control group. A total of 56 patients with TM were involved in this study: 39 patients received only DFX and 17 patients were given combined treatment DFO+DFP between August 2008 and August 2009. In addition, a control group was established from the healthy population. Blood was taken from all the patients for serum zinc levels and 24hour-urine samples were collected for urine zinc levels. Serum zinc levels were found to be 64.8±14.8μg/dL in DFX group and 66.5±15.1μg/dL in DFO+DFP group. These levels were statistically lower than that in the control group (149±54.3μg/dL) (p<0.05), but there was no statistically difference between the two different chelation groups (p>0.05). The urine zinc levels of DFX and DFO+DFP group were 662.2±428.2μg/day and 1182.3±980.3μg/day respectively (p<0.05). Urinary zinc excretion in the chelation groups (DFX and DFO+DFP) was significantly higher than the control group (395.1±208.9μg/day) (p<0.05). As a conclusion, the new chelation agent, DFX, also leads to zinc deficiency, though its urinary zinc excretion is lower. New studies are required to examine the effects of DFX on zinc extensively. Zinc levels of patients with TM should be followed up regularly and zinc supply should be given at early ages.

Bioavailability of trace elements in beans and zinc-biofortified wheat in pigs

The objectives of this experiment were to study bioavailability of trace elements in beans and wheat containing different levels of zinc and to study how the water solubility of trace elements was related to the bioavailability in pigs. Three wheat and two bean types were used: wheat of Danish origin as a control (CtrlW), two Turkish wheat types low (LZnW) and high (HZnW) in zinc, a common bean (Com), and a faba bean (Faba). Two diets were composed by combining 81 % CtrlW and 19 % Com or Faba beans. Solubility was measured as the trace element concentration in the supernatant of feedstuffs, and diets incubated in distilled water at pH 4 and 38°C for 3 h. The bioavailability of zinc and copper of the three wheat types and the two bean-containing diets were evaluated in the pigs by collection of urine and feces for 7 days. The solubility of zinc was 34-63 %, copper 18-42 %, and iron 3-11 %. The zinc apparent digestibility in pigs was similar in the three wheat groups (11-14 %), but was significantly higher in the CtrlW+Faba group (23 %) and negative in the CtrlW+Com group (-30 %). The apparent digestibility of copper was higher in the HZnW (27 %) and CtrlW+Faba (33 %) groups than in the CtrlW (17 %) and LZnW (18 %) groups. The apparent copper digestibility of the CtrlW+Com diet was negative (-7 %). The solubility and digestibility results did not reflect the concentration in feedstuffs. The in vitro results of water solubility showed no relationship to the results of trace mineral bioavailability in pigs.

Short-term effects of sibutramine on mineral status and selected biochemical parameters in obese women

The aim of this study was to assess the effect of sibutramine on mineral status and selected biochemical parameters in obese women. The study was conducted on 24 patients who received 15 mg daily doses of sibutramine for 12 weeks, and on 20 patients who received placebo. At the baseline, after the sixth and twelfth weeks of treatment, body weight and blood pressure were measured, the BMI was calculated, and samples of blood and of first morning urine were collected. Serum lipid profiles, glucose levels, and nitric oxide levels were determined. The iron (Fe), copper (Cu), zinc (Zn), calcium (Ca), and magnesium (Mg) present in the serum and urine samples were assessed. The erythrocyte hemolysate of the patients was use to assay the activity of glutathione peroxidase (GSH-Px) and superoxide dismutase (SOD). No changes were observed in BMI, blood pressure, or nitric oxide during the study. After 12 weeks of treatment, a decrease was observed in total cholesterol, LDL cholesterol, triglyceride, glucose, and ferritin levels. GSH-Px and SOD activity increased after 12 weeks of sibutramine treatment. The Mg and Cu increases was observed in serum after the sixth and twelfth weeks of treatment. It was found that the Zn level decreased in serum after the twelfth week. The elimination of Ca, Mg, Fe, Zn, and Cu in urine also declined in the twelfth week. No differences were found in the women taking the placebo. In conclusion, we found that sibutramine had a positive effect on lipid and glucose status in obese women. However, the drug disturbed the balance of minerals, especially Zn and Mg, in the subjects.

[Health risk assessment of exposure to metals in the workers of the steel foundry and in the general population of Taranto (Italy)]

OBJECTIVE

To study the urinary excretion of As, Cr, Mn, Co, Ni, Cu, Zn, Cd, Sn, Ba, Hg, Pb, Sb in workers at the Taranto integrated-cycle steel foundry and in subjects from the general population of Taranto, to assess the health risk posed by occupational exposure and environmental exposure, respectively, to these metals.

MATERIALS AND METHODS

The study included 49 steel foundry workers (exposed), working in the minerals and agglomerates pools, steel processing plants 1 and 2 and maritime plants, and 50 subjects belonging to the general population of Taranto resident at various distances from the factory (controls), randomly selected from the exposed subjects and controls enrolled in previous research conducted in 2005. A questionnaire was administered to all participants, enquiring into general characteristics, lifestyle, diet, and any medical conditions. Informed written consent to take part in the study was obtained from all subjects before enrolment. The results of environmental monitoring performed in 2005 in the workers' sectors, consisting of determining As, Cr, Mn, Ni, Cu, Zn, Cd and Pb in the respirable dust, revealed by both samplers applied in fixed positions and personal samplers, were considered. Urine samples were obtained from all participants on a Friday, to determine As and Cr by AAS and all the other metal elements by a multielement technique with ICP-MS. Urinary creatinine was also determined to make any necessary adjustments. All urine analyses were performed in 2005 within one month of urine collection.

RESULTS

In the respirable dust, As and Cd were always within the LOD, whereas Cr, Mn, Ni, Cu and Pb were 1-2 orders of magnitude below the respective TLV-TWA of the ACGIH. Mn was the only metal element that presented significantly higher urinary concentrations in exposed subjects as compared to controls, although the values in both groups were in any case within the Italian reference range. Co, Cu, Zn, Sn and Sb showed significantly higher urinary concentrations in controls than in the exposed subjects, while there were no differences in As, Cr, Cd, Ba, Hg and Pb between the two groups. Ni was within the LOD in the 60% of the subjects in the two groups. Multiple stepwise regression showed a dependence of Cr on age, of As on the number of days since the last meal of mollusks and crustaceans, of Zn on the consumption of mollusks, and of Cd and Pb on smoking expressed as the number of pack/year.

DISCUSSION

The research did not reveal higher urinary excretion of the metal elements in the steelworkers than in the subjects from the general population of Taranto resident at different distances from the factory, except for Mn, that was anyway within the reference range. This allows us to consider that there is no relevant health risk posed by occupational exposure to metal elements in the steelworkers, nor by environmental exposure to the same elements in the residents of the city of Taranto. In particular, no pollution of the living environment by metal elements of industrial origin was demonstrated, whereas other non occupational factors seem to condition the intake of these metal elements.

Divalent cations levels change in nephrotic syndrome

Divalent cations (calcium, magnesium, zinc, cooper, manganese) play an important role in various biological processes. Different acute or chronic renal disorders in children or adults modify the urinary excretion of these cations and may influence their concentrations in organism.

AIM

Evaluation of the changes of some divalent cations levels (Cu, Zn, Mg, Ca) in acute renal diseases.

MATERIAL AND METHODS

We measured plasma concentrations and urinary excretion of cations in pediatric patients with acute urinary infections. We also evaluated malondyaldehide (MDA) and total antioxidant capacity (TAC) plasma levels.

RESULTS

The obtained results show that serum levels of Ca, Cu, Zn are decreased in patients with acute urinary infections compared with a control group of healthy children, while urinary excretion of Cu and Zn there were higher in group study compared with control group. There are no significant differences of the serum magnesium concentration. Increased plasma MDA levels and decreased plasma TAC, Cu and Zn concentrations indicate an increased oxidative stress in patients with acute renal diseases.

CONCLUSIONS

Our preliminary data show that in some acute urinary conditions, such as lower urinary tract infection and pyelonephritis, appear disturbances of plasma and urinary concentrations of divalent cations. We consi der that trace elements should be measured routinely in children with renal disorders.

Low-level environmental cadmium exposure is associated with DNA hypomethylation in Argentinean women

BACKGROUND

Cadmium, a common food pollutant, alters DNA methylation in vitro. Epigenetic effects might therefore partly explain cadmium's toxicity, including its carcinogenicity; however, human data on epigenetic effects are lacking.

OBJECTIVE

We evaluated the effects of dietary cadmium exposure on DNA methylation, considering other environmental exposures, genetic predisposition, and gene expression.

METHODS

Concentrations of cadmium, arsenic, selenium, and zinc in blood and urine of nonsmoking women (n = 202) from the northern Argentinean Andes were measured by inductively coupled mass spectrometry. Methylation in CpG islands of LINE-1 (long interspersed nuclear element-1; a proxy for global DNA methylation) and promoter regions of p16 [cyclin-dependent kinase inhibitor 2A (CDKN2A)] and MLH1 (mutL homolog 1) in peripheral blood were measured by bisulfite polymerase chain reaction pyrosequencing. Genotyping (n = 172) for the DNA (cytosine-5-)-methyltransferase 1 gene (DNMT1 rs10854076 and rs2228611) and DNA (cytosine-5-)-methyltransferase 3 beta gene (DNMT3B rs2424913 and rs2424932) was performed with Sequenom iPLEX GOLD SNP genotyping; and gene expression (n = 90), with DirectHyb HumanHT-12 (version 3.0).

RESULTS

Cadmium exposure was low: median concentrations in blood and urine were 0.36 and 0.23 µg/L, respectively. Urinary cadmium (natural log transformed) was inversely associated with LINE-1 methylation (β = -0.50, p = 0.0070; β = -0.44, p = 0.026, adjusted for age and coca chewing) but not with p16 or MLH1 methylation. Both DNMT1 rs10854076 and DNMT1 rs2228611 polymorphisms modified associations between urinary cadmium and LINE-1 (p-values for interaction in adjusted models were 0.045 and 0.064, respectively). The rare genotypes demonstrated stronger hypomethylation with increasing urinary cadmium concentrations. Cadmium was inversely associated with DNMT3B (r(S) = -0.28, p = 0.0086) but not with DNMT1 expression (r(S) = -0.075, p = 0.48).

CONCLUSION

Environmental cadmium exposure was associated with DNA hypomethylation in peripheral blood, and DNMT1 genotypes modified this association. The role of epigenetic modifications in cadmium-associated diseases needs clarification.

Comparison of dermal absorption of zinc from different sunscreen formulations and differing UV exposure based on stable isotope tracing

In a pilot study to determine if zinc (Zn) from zinc oxide nanoparticles in sunscreen can penetrate human skin in vivo, nanoparticles (~30nm) of a stable isotope (52% (68)Zn enrichment) were incorporated into an essentially phytochemical-based formulation and applied to the backs of 3 human subjects twice daily for 5 days during the Southern Hemisphere winter. Blood and urine were collected prior to application and at regular intervals and up to 50 days. As observed in a larger outdoor trial following this pilot study but with a different formulation and with UV exposure: values of (68)Zn in blood continued to increase beyond the 5 day application phase with the highest measurement at 14 days after the first application; variable amounts of the (68)Zn tracer were observed in urine; and the amounts of extra Zn added to blood were small and indicate very low levels of absorption (minimal estimate <0.01% of the applied dose) through the skin. Reasons for differences in absorption detected in the stable isotope trials and previous investigations include: the sensitivity of the stable isotope method; the duration of the investigations; the number of applications of sunscreen formulation; in vitro methods with excised skin; lack of measurement of blood and urine; no skin flexing; and lack of UV exposure.