Urinary Zinc Excretion Research Articles

Association of serum zinc with mineral stress in chronic kidney disease.

The excessive cardiovascular mortality of patients with chronic kidney disease (CKD) could be linked to mineral stress, the biological consequence of calcium-phosphate nanoparticle exposure. This study investigated whether zinc is associated with mineral stress markers in CKD. Zinc and T50 (serum calcification propensity) as well as hydrodynamic radius of secondary calciprotein particles (CPP2) were measured in blood donors and CKD patients with/out dialysis. Serum zinc concentrations and T50 were reduced, while CPP2 radius was increased in CKD patients. Serum zinc levels positively correlated with T50 and inversely correlated with CPP2 radius. In a hierarchical linear regression model, T50 was associated with age, calcium, phosphate, magnesium and albumin. Addition of zinc significantly improved prediction of the model, confirming an additional contribution of zinc to T50. Similar observations were made for the association of zinc and CPP2 radius, but spiking experiments indicated that zinc may stronger modify T50 than CPP2 radius. Also, urinary zinc excretion was increased in patients with kidney disease and correlated to T50 and CPP2 radius. Serum zinc further correlated with markers of arterial stiffness in blood donors and CKD patients, but these associations did not remain significant in a multivariate linear regression model. Reduced serum zinc levels in CKD appear directly linked to lower T50 and associated with larger CPP2 radius. Further studies on the associations of zinc and mineral stress as well as putative therapeutic benefits of zinc supplementation are required.

Methods of Assessment of Zinc Status in Humans: An Updated Review and Meta-analysis.

The assessment of zinc status is difficult but essential for the identification of zinc deficiency and evaluation of interventions to improve zinc status. The purpose of this systematic review (SR) and meta-analysis was to update the previously published SR of biomarkers of zinc status, conducted by the European Micronutrient Recommendations Aligned (EURRECA) network in 2009, to answer the question: Which putative measures (biomarkers) of zinc status appropriately reflect a change in zinc intake of at least 2 weeks? A structured search strategy was used to identify articles published between January 2007 and September 2022 from MEDLINE (Ovid), Embase (Ovid), Cochrane Database of Systematic Reviews, and Cochrane Central Register of Controlled Trials (CENTRAL). Relevant articles were identified using previously defined eligibility criteria. Data were extracted and combined with data from the previous SR. A random-effects model was used to calculate pooled mean differences using STATA (StataCorp). The risk of bias and the certainty of evidence for all outcomes were assessed. Additional data on 7 of the 32 previously reported biomarkers were identified, along with data on an additional 40 putative biomarkers from studies published since 2007. Pooled data analysis confirmed that, in healthy participants, both plasma/serum zinc concentration and urinary zinc excretion responded to changes in zinc intake (plasma/serum: mean effect [95% CI], controlled studies: 2.17 µmol/L [1.73, 2.61]; P < .005, I2 = 97.8; before-and-after studies: 2.87 µmol/L [2.45, 3.30]; P < .005, I2 = 98.1%; urine zinc: 0.39 mmol/mol creatinine [0.17, 0.62]; P < .005, I2 = 81.2; 3.09 µmol/day [0.16, 6.02]; P = .039, I2 = 94.3). The updated analyses support the conclusion that plasma/serum and urinary zinc respond to changes in zinc intake in studies of healthy participants. Several additional putative biomarkers were identified, but more studies are needed to assess the sensitivity and reliability. PROSPERO no. CRD42020219843.

Abstract P170: The Association of Urinary Cadmium and Zinc With Lower Extremity Amputations. Evidence From the Strong Heart Study

Background: Cadmium is a cardiotoxic divalent metal that accumulates in the liver and kidney. It resembles the essential metal zinc, replacing it in numerous enzymes and proteins. Zinc plays a major role in insulin function. Glucose dyshomeostasis increases the loss of zinc through the urine. Cadmium has been associated with peripheral artery disease and critical limb ischemia, conditions that lead to limb amputations. Chelation treatment with edetate disodium, an agent that facilitates the excretion of cadmium from the body, was beneficial for individuals with critical limb ischemia and diabetes in several small studies. This study evaluated the association of urinary levels of cadmium and zinc with amputations in a population with a high burden of diabetes from Arizona, Oklahoma, North Dakota and South Dakota. Hypothesis: We hypothesize that urinary cadmium and zinc levels are related to prevalent amputations in the SHS cohort. Methods: We included 2,724 participants from the Strong Heart Study, a population-based cohort study in 12 American Indian communities, recruited in 1989-1991 and followed for amputations through 1998-1999. Trained staff identified amputations of the lower extremity through visual examination at the baseline visit. We censored traumatic amputations. Baseline metal levels in spot urine samples were divided by urinary creatinine to account for urine dilution. Results: Mean age was 56.4 years, 41.5% participants were male, and 42% had diabetes. We identified a total of 35 (1.3%) amputations of the lower extremities during the study period. Median urinary levels were 0.97 μg/g for cadmium and 0.56 mg/g for zinc. Higher levels of urinary cadmium and zinc were positively associated with the presence of amputations. The odds ratios of prevalent amputations for an IQR of cadmium and zinc distribution were 1.54 (1.00, 2.38) and 2.24 (1.48, 3.39), respectively, in models adjusted for sociodemographic, lifestyle (tobacco and alcohol intake), and other factors (BMI, hypertension and diabetes status, HDL and LDL-cholesterol, and estimated glomerular filtration rate). The associations remained after further adjustment for fasting plasma glucose levels. Urinary cadmium and zinc levels were positively correlated (r=0.24, P&lt;0.001). Conclusions: Urinary cadmium and zinc were positively associated with the presence of lower extremity amputations in American Indian adults with a high burden of diabetes. These results support the current evidence of cadmium as a cardiometabolic risk factor, and the potential role of impaired zinc metabolism, reflected as increased urinary zinc excretion, in vascular complications of diabetes.

Serum zinc levels in cancer patients are low and difficult to elevate when complicated by liver cirrhosis: A retrospective study.

In this study, we analyzed blood zinc concentration in patients with various cancer types and the degree of improvement in relation to the underlying disease following treatment with zinc preparations. Serum zinc levels of 530 cancer patients whose blood zinc levels were measured at our hospital from 2016 to 2021 were retrospectively examined in accordance with the primary disease. Changes in zinc levels were analyzed in 155 patients whose zinc levels had been measured on 2 or more occasions in accordance with whether they had received zinc preparations. In addition, the concentration course of zinc before and after zinc formulation administration in 73 patients was examined in accordance with the presence or absence of liver cirrhosis complications. Mean serum zinc levels were below normal in all carcinomas measured, and zinc levels were significantly lower in cirrhosis-hepatocarcinoma cases than in other primary disease cases. Furthermore, serum zinc levels in patients who did not receive zinc preparations decreased significantly over time. In patients who received zinc preparations, the elevated levels of zinc after treatment were significantly lower in patients with cirrhosis than in those without cirrhosis. There was a weak inverse correlation between pre-dose zinc concentration and increased zinc concentration in patients with cirrhosis. In the analysis of covariance, the presence of liver cirrhosis was predominantly correlated with elevated zinc per dose. In summary, serum zinc levels in cancer patients are low and especially low in cancer patients with liver cirrhosis compared with those without cirrhosis after the administration of zinc preparations.

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

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). 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. 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. 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.

Toward revising dietary zinc recommendations for children aged 0 to 3 years: a systematic review and meta-analysis of zinc absorption, excretion, and requirements for growth.

The Food and Agriculture Organization of the United Nations and the World Health Organization are updating their dietary zinc recommendations for children aged 0 to 3 years. The aim of this review was to retrieve and synthesize evidence regarding zinc needs for growth as well as zinc losses, absorption, and bioavailability from the diet. MEDLINE, Embase, and Cochrane Library databases were searched electronically from inception to August 2020. Studies assessing the above factors in healthy children aged 0 to 9 years were included, with no limits on study design or language. Ninety-four studies reporting on zinc content in tissue (n = 27); zinc absorption (n = 47); factors affecting zinc bioavailability (n = 30); and endogenous zinc losses via urine, feces, or integument (n = 40) met the inclusion criteria. Four reviewers extracted data and two reviewers checked for accuracy. Studies were synthesized narratively, and meta-analyses of zinc losses and gains as well the subgroups of age, type of feeding, country's income, and molar ratio of phytate to zinc were conducted. Meta-analysis revealed an overall mean (95%CI) urinary and endogenous fecal zinc excretion of 17.48 µg/kg/d (11.80-23.15; I2 = 94%) and 0.07 mg/kg/d (0.06-0.08; I2 = 82%), respectively, with a mean fractional zinc absorption of 26.75% (23.69-29.81; I2 = 99%). Subgrouping by age revealed differences in mean values associated with the transition from milk-based diets to solid food during the first 3 years of life. This review synthesizes data that may be used to formulate zinc requirements in young children. Results should be interpreted with caution because of considerable heterogeneity in the evidence. PROSPERO registration number CRD42020215236.

Urinary Zinc and Incident Type 2 Diabetes: Prospective Evidence From the Strong Heart Study.

Hyperglycemia can increase urinary zinc excretion. We evaluated the association of higher urinary zinc level with new diagnosis of incident type 2 diabetes mellitus (T2DM) in adult populations with a high burden of T2DM from AZ, OK, and ND and SD. We also assessed the cross-sectional association of urinary zinc levels with prevalent prediabetes. We included 1,339 adults free of T2DM at baseline (1989-1991) followed through 1998-1999 in the Strong Heart Study (SHS) and 1,905 family members of SHS participants followed as part of the Strong Heart Family Study (SHFS) through 2006-2009. T2DM incidence was 14.7% (mean follow-up 6.6 years) in the SHS and 13.5% (mean follow-up 5.6 years) in the SHFS. After adjustment for sex, site, education, smoking status, BMI, and estimated glomerular filtration rate, the hazard ratio of T2DM in comparing 75th vs. 25th percentiles of urinary zinc distribution was 1.21 (95% CI 1.08, 1.36) in the SHS and 1.12 (0.96, 1.31) in the SHFS. These associations were attenuated but significant in the SHS after adjustment for HOMA of insulin resistance (HOMA-IR) score. With exclusion of participants with prediabetes at baseline, urinary zinc remained significantly associated with T2DM in the SHS. In cross-sectional analyses, prediabetes was associated with higher urinary zinc levels. Urinary zinc levels were associated with T2DM incidence and prediabetes prevalence even after adjustment for HOMA-IR in populations with a high burden of T2DM. These results highlight the importance of zinc metabolism in diabetes development.

The potential of spot urine as a biomarker for zinc assessment in Malawian children and adults.

Population-level assessment of zinc deficiency remains a challenge due to the lack of suitable biomarkers. Spot urinary zinc concentration (UZC) has the potential to provide information on population zinc status in large-scale surveys, but there is no established cut-off point indicating deficiency. A strong correlation between this biomarker and an established biomarker such as serum zinc concentration (SZC) in paired samples (i.e., from the same individual), could identify the thresholds indicating zinc deficiency. This study, therefore, aimed to regress spot UZC from school-aged children and women from the Malawi micronutrient survey with paired SZC data using a linear mixed-effects model. The nested variance components indicated no linear relationship between the UZC and SZC data, irrespective of adjustments for inflammation and hydration. Thresholds of urinary zinc excretion that have been suggested by expert panels were applied to the spot UZC data, as a post-hoc analysis. The zinc deficiency prevalence estimates derived from these suggested thresholds were not similar to the estimates from the SZC data, and further research is required to understand whether spot UZC can still provide useful information in population zinc assessment.

Zinc Kinetics Correlate With Length-for-Age z Scores in Bangladeshi Infants.

Stunting [length-for-age z score (LAZ) &lt;-2] has multiple causes and is prevalent in areas with low dietary zinc (Zn) intake. Zinc kinetics from non-stunted infants were used in a published model for predicting linear growth; here, we directly measure zinc kinetics in stunted infants. Zinc kinetics were determined in 9-month-old Bangladeshi infants (n = 10), who were non-wasted [weight-for-length z score (WLZ) &gt; -2], ranging in LAZ from -2.9 to -0.43. Stable isotopes were administered 2 hours after a meal as oral ( 70 Zn) and intravenous ( 67 Zn) tracers. After isotope administration, blood was sampled within 5 hours and all urine and feces were collected for 24 hours. Urine was sampled twice-daily out to 9 days. Data were analyzed by compartmental modeling. Daily zinc intake was estimated by the model as the sum of zinc used for growth plus that lost via urine and feces. Zinc absorbed (the amount required to maintain steady state) was the sum of zinc used for growth plus urine and endogenous fecal excretions. The LAZ score correlated with serum zinc concentration ( R = 0.77, P = 0.001), urinary zinc excretion ( R = 0.66, P = 0.010), and fractional zinc absorption from calculated daily intake ( R = 0.58, P = 0.030). In stunted infants (n = 8), the amount of zinc absorbed did not increase with calculated zinc intake unlike published values for non-stunted infants. Zinc kinetics in Bangladeshi infants correlate with LAZ and show that malabsorption of supplemental sources of zinc may occur in stunted infants.

Effect of Calcium and Vitamin D on Zinc Balance in Rats

ObjectivesThe most pronounced consequences of nutritional calcium deficiency are observed with a parallel deficiency of vitamin D. In this regard, the creation and evaluation of foods optimally fortified with calcium and vitamin D is an important task. The aim of this study was to experimentally study the effect of different levels of alimentary calcium and vitamin D on the indices of mineral metabolism. MethodsWhite growing male Wistar rats for 28 days were on semisynthetic casein rations (RCC), with different content of calcium and vitamin D: group 1 - control RCC (physiological norm of calcium and vitamin D); group 2 - RCC without calcium + 2 norms of vitamin D; group 3 - RCC with two rates of calcium (carbonate) and two rates of vitamin D; group 4 - RCC with two rates of calcium (alginate) and two rates of vitamin D and group 5 - RCC with three levels of vitamin D. The levels of calcium and zinc in serum and urine were studied. ResultsWhen the diet was fortified with calcium (carbonate or alginate) in combination with vitamin D (groups 3 and 4), there was no increase in urinary zinc excretion. Its concentration (μmol / L) was recorded at the level of 5.47 ± 1.07 (14th day) and 4.74 ± 1.03 (28th day) in animals of the 3rd group and 5.97 ± 1, 62 and 5.09 ± 1.51 in animals of the 4th group compared with similar indicators in the control: 6.27 ± 1.59 and 4.94 ± 1.08. There were no significant differences in the concentration of zinc in the blood serum in animals of these groups. In animals of the 5th group, the loss of zinc in the urine was 80% more (p < 0.05) than in the control group, and in animals of the 2nd group - by 54% more (p > 0.05). In animals of the 5th group, high concentrations of calcium in urine (mmol / l) were also noted: 1.54 ± 0.27 (p < 0.05) compared with 0.62 ± 0.05 in the control. ConclusionsThe obtained result does not confirm the previously published data on the risk of zinc deficiency (due to its losses in the urine) when enriching the diet with calcium. At the same time, the isolated enrichment of the diet with vitamin D, both with calcium deficiency and with its physiological level, led to an increasing excretion of zinc in the urine during the entire observation period. Thus, vitamin D fortification in a diet low in calcium results in urinary loss of zinc and calcium. Funding SourcesNo funding.

Nutrient Intake and Nutrition Status in Vegetarians and Vegans in Comparison to Omnivores - the Nutritional Evaluation (NuEva) Study.

IntroductionIn recent years, vegetarian and vegan diets became increasingly important as they are associated with beneficial health outcomes. Therefore, the NuEva study compares the impact of flexitarian, vegetarian, or vegan diets with omnivorous nutritional habits on nutrient intake and risk factors for non-communicable diseases.MethodsA dietary protocol was kept over five days and blood and 24h urine samples were collected to examine the impact of dietary habits [omnivores, n = 65 (Median/Interquartile range: 33/17 yrs.), flexitarians, n = 70 (30/17 yrs.), ovo-lacto vegetarians, n = 65 (28/14 yrs.), vegans, n = 58 (25/10 yrs.)] on nutrient intake, nutrient concentrations in plasma, serum or 24h urine, body composition, and blood lipids.ResultsThe increased exclusion of animal based foods in the diet (omnivores < flexitarians < vegetarians < vegans) is associated with a decreased intake of energy, saturated fat, cholesterol, disaccharides, and total sugar as well an increased intake of dietary fibers, beta carotene, vitamin E and K. The combined index of the B12 status (4cB12 score) in vegetarians (0.02/0.75) was lower compared to omnivores (0.34/0.58; p ≤ 0.05) and flexitarians (0.24/0.52; p ≤ 0.05). In omnivores vitamin A, vitamin E, ferritin, and the urinary excretion of selenium, iodine, and zinc were higher than in vegans (p ≤ 0.05). In contrast, vegans had the highest concentrations of biotin, folate, and vitamin C. Flexitarians, vegetarians, and vegans had a lower body weight, BMI, and body fat percentage in comparison to omnivores (p ≤ 0.05). In omnivores the concentrations on total cholesterol, total cholesterol/HDL cholesterol ratio, LDL cholesterol, LDL cholesterol/HDL cholesterol ratio, apolipoprotein B, and apolipoprotein B/ apolipoprotein A1 ratio were higher than in vegetarians and vegans (p ≤ 0.05).ConclusionThe NuEva study confirms the position of the Academy of Nutrition and Dietetics that adequately planned vegetarian diets are healthy, nutritionally adequate, and may provide health benefits in the prevention and treatment of non-communicable diseases. Nevertheless, critical nutrients were identified for all groups studied. This highlights the need to develop individual nutritional concepts to ensure an adequate nutrient intake.

Effect of Furosemide and Spironolactone on urinary zinc excretion in rats

Background: Zinc deficiency is associated with numerous diseases including hypertension, diabetes, obesity, immune dysregulation, cancer, depression and congenital anomalies. There are many reasons of zinc deficiency including some medications. If zinc supplementation is used with these medicines than many diseases can be prevented.&#x0D; Subjects and methods: This experimental study was planned to observe the effect of single diuretic dose of furosemide and spironolactone on zinc urinary excretion and blood levels in normal rats. Eighteen adult healthy male Sprague Dawley rats were randomly divided into three groups. After saline load rats were given distilled water, furosemide (10 mg/kg) and spironolactone (20 mg/kg) as single oral dose. Blood and urine samples were collected after five hours and analysed for zinc concentration by flame atomic absorption spectrophotometer.&#x0D; Results: Single oral dose of furosemide and spironolactone highly significantly increased urinary zinc excretion (p-value &lt;0.001 vs normal control), and increased blood zinc level (p-value &lt;0.001 vs. normal control). Value of both variables were significantly higher in furosemide-treated group (p-value &lt;0.001 vs. furosemide-treated).&#x0D; Conclusion: Results of this research conclude that furosemide and spironolactone increase urinary zinc excretion when used for short period. It is also postulated that blood zinc concentration is not reliable measure to assess the zinc status of the body because its level shows compensatory rise during deficiency states.

Biomarkers of Zinc and Copper Status and Associated Factors in Outpatients with Ischemic and Non-Ischemic Heart Failure

Background: Few studies have explored the impact of ischemic and non-ischemic etiologies of heart failure and other factors associated with heart failure on zinc and copper status. This study examined zinc and copper status in 80 outpatients with ischemic (n = 36) and non-ischemic (n = 44) heart failure and associations with biodemographic, clinical, biochemical, and nutritional parameters. Materials: Biomarkers of plasma zinc and copper, copper-zinc ratio, 24-h urinary zinc excretion, ceruloplasmin, and dietary intake of zinc and copper were assessed. Plasma zinc and copper and urinary zinc were measured by inductively coupled plasma mass spectrometry (ICP-MS). Results: Patients with ischemic heart failure showed lower dietary zinc intake and higher dietary copper intake (both p = 0.02). Zinc and copper in plasma, copper-zinc ratio, ceruloplasmin, and 24-h urinary zinc excretion showed no statistical differences between the groups (all p ≥ 0.05). An inverse association was found between age (β =−0.001; p = 0.005) and the use of diuretics (β = -0.047; p = 0.013) and plasma zinc. Copper levels in plasma (β = 0.001; p < 0.001), and albumin (β = 0.090; p<0.001) were directly associated with plasma zinc. A positive association was found between ceruloplasmin (β = 0.011; p < 0.001), gamma-glutamyl transferase (β = 0.001; p < 0.001), albumin (β = 0.077; p = 0.001), and high-sensitivity c-reactive protein (β = 0.001; p = 0.024) and plasma copper. Conclusion: Zinc and copper biomarkers in clinically stable patients with heart failure did not seem to be responsive to the differences in zinc and copper intake observed in this study, regardless of heart failure etiology. The predictors of plasma zinc and copper levels related to oxidative stress and inflammation should be monitored in heart failure clinical practice.

Urinary Metals and Incident Diabetes in Midlife Women: Study of Women’s Health Across the Nation (SWAN)

Background: Environmental exposure to metals may play a role in the pathogenesis of diabetes, however, evidence from human studies is limited. We prospectively evaluated the associations of 20 urinary metal concentrations and their mixtures with incident diabetes in the Study of Women’s Health Across the Nation, a multi-site, multi-ethnic cohort study of midlife women. Methods: The sample included 1,226 white, black, Chinese and Japanese-American women, aged 45-56 years, free of diabetes at baseline (1999-2000) who were followed through 2016. Concentrations of 20 metals (arsenic, barium, beryllium, cadmium, cobalt, chromium, cesium, copper, mercury, manganese, molybdenum, nickel, lead, antimony, tin, thallium, uranium, vanadium, tungsten and zinc) were measured in urine specimens using high-resolution inductively coupled plasma-mass spectrometry at baseline. Incident diabetes was identified annually. Exposure to metal mixtures were captured using k-means clustering. Results: After multivariable adjustment, the hazard ratios (HR) (95% CI) of diabetes associated with each doubling increase in urinary metal concentrations were 1.13 (1.04, 1.23) for arsenic and 1.22 (1.09, 1.37) for lead, in Cox proportional hazards models after controlling for multiple comparison. A doubling in urinary excretion of zinc was associated with higher diabetes risk (adjusted HR 1.47, 95% CI: 1.27, 1.70). Two distinct exposure patterns to metal mixtures- “high” vs. “low”-were identified. Adjusted HR of diabetes associated with “high” exposure pattern compared with “low” was 1.38 (1.09, 1.75). Conclusions: Exposure to arsenic and lead, an increase urinary excretion of zinc, as well as a high overall exposure to metal mixtures were associated with elevated diabetes risks. Future studies should further investigate the underlying mechanisms by which metals may influence diabetes.

Biomarkers of Cardiovascular Risk in Obese Women and their Relationship with Zinc Status

Background: Excessive adipose tissue, in the case of common obesity, has been associated with an endocrine-metabolic alteration that contributes to a manifestation of dyslipidemia. To identify mechanisms which are involved in disorders of lipid metabolism, several nutrients have been studied, especially zinc, which act by regulating transcription factors that are important for synthesis and oxidation of lipids and act as an anti-inflammatory and antioxidant nutrient. Thus, the study makes an assessment of the zinc status and biomarkers of cardiovascular risk in obese women. Methods: A case-control study enrolling obese (body mass index (BMI) ≥35 kg/m²) and eutrophic (BMI 18.5-24.9 kg/m²) Brazilian women was conducted. Dietary zinc intake was assessed by the three-day food registry. Plasma, erythrocyte and urinary zinc concentrations were determined by inductively coupled plasma optical emission spectrometry. Cardiovascular risk was assessed by plasma concentrations of lipid fractions, and by anthropometric measures. Results: Both groups showed a dietary zinc intake above the recommendations, with no statistical difference between them (p &gt;0.05). Mean plasma and erythrocyte zinc concentrations were significantly reduced in obese women, compared to the control group (p &lt;0.05). Urinary zinc excretion was significantly higher in obese women (p &lt;0.05), who also had a significantly higher cardiovascular risk when compared to the control group (p &lt;0.05). An inverse correlation between dietary zinc intake and waist-hip ratio was found in obese women. Conclusion: Obese women presented zinc redistribution characterized by reduced concentrations in plasma and erythrocytes, dietary zinc intake above the recommended, and increased zinc excretion in the urine. This study shows dyshomeostasis of zinc in obesity, a possible role in adiposity control and, consequently, its protective role against cardiovascular risk, due to its influence on risk biomarkers, such as waist-hip ratio.

Urinary metals and incident diabetes in midlife women: Study of Women’s Health Across the Nation (SWAN)

IntroductionEnvironmental exposure to metals may play a role in the pathogenesis of diabetes; however, evidence from human studies is limited. We prospectively evaluated the associations of 20 urinary metal concentrations...

Renal handling of zinc in chronic kidney disease patients and the role of circulating zinc levels in renal function decline.

Zinc deficiency is commonly encountered in chronic kidney disease (CKD). The aims of this study were to assess whether zinc deficiency was related to increased renal excretion of zinc and to the progression of CKD. Plasma and 24-h urinary zinc levels, urinary electrolytes and uromodulin were measured in 108 CKD patients and 81 individuals without CKD. Serum creatinine values were collected for 3years to calculate the yearly change in estimated glomerular filtration rate (eGFR). Multivariable regression analysis was performed to assess the association between baseline zinc levels and yearly change in eGFR. CKD patients had lower circulating zinc levels and higher 24-h urinary zinc excretion than non-CKD participants (612.4 ± 425.9 versus 479.2 ± 293.0 µg/day; P = 0.02). Fractional excretion (FE) of zinc was higher and it significantly increased at more advanced CKD stages. Zinc FE was correlated negatively with 24-h urinary uromodulin excretion (r=-0.29; P < 0.01). Lower baseline plasma zinc levels were associated with a faster yearly decline of renal function in age, gender, diabetes and hypertension adjusted models, but this relationship was no longer significant when baseline eGFR or proteinuria were included. Zinc levels are lower in CKD, and not compensated by reduced renal zinc excretion. The inverse association between urinary zinc excretion and uromodulin possibly points to an impaired tubular activity, which could partly account for zinc imbalance in CKD. These data suggest that zinc status is associated with renal function decline, but further studies elucidating the underlying mechanisms and the potential role of zinc supplements in CKD are needed.

Effect of Tramadol Addiction Alone and Its Co-abuse with Cannabis on Urinary Excretion of Copper, Zinc, and Calcium among Egyptian Addicts

Effect of Tramadol Addiction Alone and Its Co-abuse with Cannabis on Urinary Excretion of Copper, Zinc, and Calcium among Egyptian Addicts

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

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

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 8km/h, respectively, and increasing the speed at 1km/h every 400m, 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.