Erythrocyte Zinc Concentrations Research Articles

Association Between Parameters of Cortisol Metabolism, Biomarkers of Minerals (Zinc, Selenium, and Magnesium), and Insulin Resistance and Oxidative Stress in Women with Obesity.

This is a cross-sectional study with women divided into a group of those with obesity (n = 80) and a control group (n = 94). Statistical analysis was conducted using the SPSS program. There were high values of GPx and TBARS and reduced values of SOD in women with obesity compared to the control group. Obese women showed increased concentrations of cortisol in serum and urine as well as hypozincemia, hyposelenemia, and hypomagnesemia and increased urinary excretion of these minerals. There was a negative correlation between the cortisol/cortisone ratio and erythrocyte zinc and selenium concentrations and a significant positive correlation between GPx and SOD activity and erythrocyte and plasma concentrations of zinc and selenium. The results of the study suggest the influence of adiposity on the increase in cortisol concentrations and the role of this hormone in the compartmentalization of the minerals zinc, selenium, and magnesium. However, the association study does not allow identifying the impact of such action on the antioxidant defense system and insulin sensitivity.

Deficiência de zinco na doença de Alzheimer: um estudo transversal com grupo comparação

Abstract Objective To identify whether there is a difference in plasma and erythrocyte zinc concentration in older adults with and without Alzheimer's disease. Methods Crosssectional study with a comparative group, conducted with older adults with and without Alzheimer's disease, matched by sex, education, and age. Zinc concentration was measured by atomic absorption spectrophotometry in a graphite furnace. Results There were 102 people, 68 in the healthy group (NDA-g) and 34 in the group with disease (AD-g). The AD-g group had lower plasma zinc concentrations and higher frequency in the first quartile for intraerythrocyte zinc concentrations. Plasma and erythrocyte concentrations did not correlate with the time of diagnosis and age in both groups. In the logistic regression analysis, plasma concentration was associated with AD-g (OR=0.964; p=0.028). Conclusion Older people with Alzheimer's disease have lower plasma and erythrocyte zinc concentrations.

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 >0.05). Mean plasma and erythrocyte zinc concentrations were significantly reduced in obese women, compared to the control group (p <0.05). Urinary zinc excretion was significantly higher in obese women (p <0.05), who also had a significantly higher cardiovascular risk when compared to the control group (p <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.

Zinc gluconate supplementation impacts the clinical improvement in patients with ulcerative colitis.

Ulcerative colitis is an inflammatory bowel disease that affects the mucous membrane of the colon. The pathogenesis is not clear, but there is evidence of a complex interaction between genetic, environmental, and immunological factors. In this regard, we highlight the role of zinc in the immune system and probable control of the disease. This study evaluated the effect of zinc supplementation on the inflammatory response in patients with ulcerative colitis. A blind interventional study involving 41 patients of both sexes, who underwent either zinc gluconate supplementation (n = 23), or treatment with a placebo (corn starch) (n = 18). Patients were evaluated for dietary zinc intake, plasma and erythrocyte zinc concentrations, and serum levels of Th1/Th2/Th17 type cytokines at baseline (T0) and 30 (T1) and 60 (T2) days after intervention. Patients in the zinc supplementation group had a lower probability of having an adequate zinc intake than placebo. In this same group, there was a significant difference between plasma zinc concentrations (T1 in relation to T0, T2 in relation to T1, and T2 in relation to T0) and erythrocyte zinc (T1 in relation to T0 and T2 in relation to T1). Zinc supplementation resulted in significant changes in the concentrations of IL-2 and IL-10 without differences in the other interleukins. Zinc gluconate intervention in patients with ulcerative colitis improves the nutritional status of this mineral in these patients and positively influences their clinical outcome, reinforcing the role of zinc as an important dietary component in disease control.

No association between zinc and thyroid activity in obese women.

Obesity is characterized by changes in the metabolism of zinc and thyroid hormones. Studies have also shown the role of zinc in the function and metabolism of thyroid. The present study aimed to evaluate the relationship between serum concentrations of thyroid hormones, dietary zinc intake and zinc distribution in obese women. A case-control study was conducted enrolling 98 women aged between 20 and 50years old who were divided into case group (BMI≥35kg/m2) and control group (BMI=18.5-24.9kg/m2). Patients underwent anthropometric measurements and analysis of dietary zinc intake, which was performed by a three-day food record. Zinc concentrations in plasma and erythrocytes were determined by inductively coupled plasma optical emission spectrometry. Serum concentrations of thyroid hormones and antibodies were determined by chemiluminescence. Mean values of dietary zinc intake were higher than recommended (10.37±3.12mg/day and 11.37±4.36mg/day for control and obeses, respectively). Obese women had reduced plasma (67.22±5.96μg/dL) and erythrocyte (37.16±3.64μg Zn/gHb) zinc concentrations when compared to the control group (plasma: 89.71±13.33μg/dL; erythrocyte: 42.68±3.73μg Zn/gHb) (p<0.001). Serum TSH (control: 2.62±1.29 μIU/mL; obeses: 3.08±1.13 μIU/mL), Free T3 (control: 2.19±0.63pg/dL; obeses: 2.09±0.34pg/dL), and Free T4 (control: 1.12±0.31ng/dL; obeses: 1.09±0.19ng/dL) concentrations were within the normal range in both groups, without significant difference between them (p>0.05). There was no correlation between thyroid hormone concentrations and zinc parameters (p>0.05). Although obese women presented hypozincemia, they had normal levels of thyroid hormones and no correlation was found between the studied parameters.

No Relation Between Zinc Status and Inflammatory Biomarkers in Adolescent Judokas.

This study aimed to assess the relation between zinc status and inflammation biomarkers in adolescent judokas. This cross-sectional study included 52 male adolescents, aged between 14 and 19 years, who were subdivided into two groups: judoka group (n = 25) and control group (n = 27). Zinc intake was monitored using 3-day food records and the NutWin software version 1.5. The plasma and erythrocyte zinc concentrations were determined by flame atomic absorption spectrophotometry. Analysis of cytokines (IL-1β, IL-6, and TNF-α) was performed. The mean values of zinc concentration in the diet were found to be higher than those recommended (11.0±3.9 mg/day and 20.3±11.9 mg/day for control group and judokas, respectively) although there was no significant difference between the groups. The mean plasma concentrations of zinc were below the reference range (71.4±16.0 μg/dL and 71.9±13.8 μg/dL for control group and judokas, respectively), without a significant difference between the groups. The mean concentrations of zinc erythrocyte were within the reference range (41.2±8.6 μg/gHb and 42.6±11.3 μg/gHb for control group and judokas, respectively), without a significant difference between the groups. There was no significant difference in the inflammatory biomarkers between the judokas and controls. There was not a significant correlation between biochemical parameters of zinc and inflammation biomarkers in adolescent judokas. Regarding the data found in the study, it can be concluded that the athletes evaluated have low plasma zinc concentrations, normal erythrocyte values, and high dietary intake of zinc. Moreover, the study don't show a relationship between zinc parameters and inflammatory markers evaluated.

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

BackgroundHypotensive therapy leads to a number of trace elements metabolism disturbances. Zinc balance is frequently affected by antihypertensive treatment. AimTo 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. MethodsIn 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. ResultsAntihypertensive 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. ConclusionHypotensive 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.

Bioimpedance parameters in adolescent athletes in relation to bone maturity and biochemical zinc indices

Phase angle (PA) is derived from resistance and reactance determined by bioimpedance analysis (BIA) and it appears to relate to cellular stability and integrity. Interpretation of PA values could be complemented by bioelectrical impedance vector analysis (BIVA), which relates to body hydration and structure. Body composition, age, sex, and nutrients are known to stabilize cell membranes, such as zinc, have been related to PA although information is scarce in adolescent athletes. The aim of the present study was to assess the association of body composition, skeletal maturity and zinc biochemical indices with phase angle and bioelectrical impedance parameters, in forty male adolescent soccer athletes (13.4 ± 0.6 years). BIA was performed with a single-frequency tetrapolar analyzer. PA and BIVA were determined using resistance and reactance BIA data. Plasma and erythrocyte zinc concentrations were measured using inductively coupled plasma-optical emission spectrometry. Body composition was determined by dual-energy X-ray absorptiometry, and bone age by hand X-ray measurements. PA was higher in adolescents classified by bone age as “Early” (6.8 ± 0.9°) compared to “Late” (5.7 ± 0.5°) (p < 0.05). PA correlated with bone age (r = 0.562), BMI (r = 0.382), fat-free mass (r = 0.468), and erythrocyte zinc (r = 0.379) (p < 0.05). BIVA confidence ellipses were sensitive to skeletal maturity status. Phase angle was higher in adolescents with erythrocyte zinc concentration above the median (>0.66 μmol.g hemoglobin-1) compared to those below the median. Multiple linear regression analysis showed that bone age (B = 0.254, p = 0.001) and erythrocyte zinc concentration (B = 1.168, p = 0.047) were significantly related to PA in this group, and accounted for 34% of its variability. Our results indicate that bone age and zinc erythrocyte contribute to PA values in the young male soccer athletes and that BIVA is influenced by skeletal maturity status in this group.

Zinc and selenium status in critically ill patients according to severity stratification.

The aim of this study was to evaluate the concentrations of zinc and selenium in different biological materials and to associate them with the clinical severity score according to the Simplified Acute Physiology Score (SAPS) III. The study was conducted in a 10-bed general intensive care unit of the Américo Brasiliense State Hospital/SP, with 95 patients stratified by the SAPS III score cutoff points (63.5 points) as less or more severe and by the diagnosis of sepsis. Analyses of zinc and selenium concentrations in plasma, erythrocytes, and urine were conducted. Plasma concentrations were found to be lower than the reference values for both micronutrients (8.4±4 and 0.18±0.06μmol/L, respectively, for zinc and selenium), and urinary zinc concentration was higher than the reference (38.6±35.8μmol/24h). The mean selenium plasma concentration was significantly lower in patients with greater severity, which was not observed for zinc (P>0.05). The mean selenium plasma and erythrocyte concentrations were significantly different between the groups diagnosed with sepsis, which was not observed in the analysis of zinc. Albumin levels (r=-0.26; P=0.01) and C-reactive protein (r=0.40; P<0.001) correlated with the SAPS III severity score. Plasma concentrations of zinc and selenium are low in critically ill patients upon admission to the intensive care unit and may make these patients more susceptible to oxidative stress. The low concentration of erythrocyte selenium may represent an inadequate intake by this population. Additional studies using new biomarkers should be performed with the objective of identifying values for the local population.

Association of reduced zinc status with poor glycemic control in individuals with type 2 diabetes mellitus

This study evaluated the relationship between the zinc-related nutritional status and glycemic and insulinemic markers in individuals with type 2 diabetes mellitus (T2DM). A total of 82 individuals with T2DM aged between 29 and 59 years were evaluated. The concentration of zinc in the plasma, erythrocytes, and urine was determined by the flame atomic absorption spectrometry method. Dietary intake was assessed using a 3-day 24-h recall. In addition, concentrations of serum glucose, glycated hemoglobin percentage, total cholesterol and fractions, triglycerides, and serum insulin were determined. The insulin resistance index (HOMA-IR) and β-cell function (HOMA- β) were calculated. The markers of zinc status (plasma: 83.3±11.9μg/dL, erythrocytes: 30.1±4.6μg/g Hb, urine: 899.1±622.4μg Zn/24h, and dietary: 9.9±0.8mg/day) were classified in tertiles and compared to insulinemic and glycemic markers. The results showed that lower zinc concentrations in plasma and erythrocytes, as well as its high urinary excretion, were associated with higher percentages of glycated hemoglobin, reflecting a worse glycemic control in individuals with T2DM (p<0.05). Furthermore, there was a significant inverse correlation between plasma zinc levels and glycated hemoglobin percentage (r=−0.325, p=0.003), and a positive correlation between urinary zinc excretion and glycemia (r=0.269, p=0.016), glycated hemoglobin percentage (r=0.318, p=0.004) and HOMA-IR (r=0.289, p=0.009). According to our study results, conclude that T2DM individuals with reduced zinc status exhibited poor glycemic control.

Zinc Status Biomarkers and Cardiometabolic Risk Factors in Metabolic Syndrome: A Case Control Study.

Metabolic syndrome (MS) involves pathophysiological alterations that might compromise zinc status. The aim of this study was to evaluate zinc status biomarkers and their associations with cardiometabolic factors in patients with MS. Our case control study included 88 patients with MS and 37 controls. We performed clinical and anthropometric assessments and obtained lipid, glycemic, and inflammatory profiles. We also evaluated zinc intake, plasma zinc, erythrocyte zinc, and 24-h urinary zinc excretion. The average zinc intake was significantly lower in the MS group (p < 0.001). Regression models indicated no significant differences in plasma zinc concentration (all p > 0.05) between the two groups. We found significantly higher erythrocyte zinc concentration in the MS group (p < 0.001) independent from co-variable adjustments. Twenty-four hour urinary zinc excretion was significantly higher in the MS group (p = 0.008), and adjustments for age and sex explained 21% of the difference (R2 = 0.21, p < 0.001). There were significant associations between zincuria and fasting blood glucose concentration (r = 0.479), waist circumference (r = 0.253), triglyceride concentration (r = 0.360), glycated hemoglobin concentration (r = 0.250), homeostatic model assessment—insulin resistance (r = 0.223), and high-sensitivity C-reactive protein concentration (r = 0.427) (all p < 0.05) in the MS group. Patients with MS had alterations in zinc metabolism mainly characterized by an increase in erythrocyte zinc and higher zincuria.

A moderate increase in dietary zinc reduces DNA strand breaks in leukocytes and alters plasma proteins without changing plasma zinc concentrations1–3

Background: Food fortification has been recommended to improve a population’s micronutrient status. Biofortification techniques modestly elevate the zinc content of cereals, but few studies have reported a positive impact on functional indicators of zinc status.Objective: We determined the impact of a modest increase in dietary zinc that was similar to that provided by biofortification programs on whole-body and cellular indicators of zinc status.Design: Eighteen men participated in a 6-wk controlled consumption study of a low-zinc, rice-based diet. The diet contained 6 mg Zn/d for 2 wk and was followed by 10 mg Zn/d for 4 wk. To reduce zinc absorption, phytate was added to the diet during the initial period. Indicators of zinc homeostasis, including total absorbed zinc (TAZ), the exchangeable zinc pool (EZP), plasma and cellular zinc concentrations, zinc transporter gene expression, and other metabolic indicators (i.e., DNA damage, inflammation, and oxidative stress), were measured before and after each dietary-zinc period.Results: TAZ increased with increased dietary zinc, but plasma zinc concentrations and EZP size were unchanged. Erythrocyte and leukocyte zinc concentrations and zinc transporter expressions were not altered. However, leukocyte DNA strand breaks decreased with increased dietary zinc, and the level of proteins involved in DNA repair and antioxidant and immune functions were restored after the dietary-zinc increase.Conclusions: A moderate 4-mg/d increase in dietary zinc, similar to that which would be expected from zinc-biofortified crops, improves zinc absorption but does not alter plasma zinc. The repair of DNA strand breaks improves, as do serum protein concentrations that are associated with the DNA repair process. This trial was registered at clinicaltrials.gov as NCT02861352.

RELATIONSHIP BETWEEN ZINCEMIA, SUPEROXIDE DISMUTASE ACTIVITY AND MARKER OF OXIDATIVE STRESS IN WOMEN WITH BREAST CANCER.

studies show changes in zinc metabolism in women with breast cancer. This mineral has antioxidant action, and disorders in its biochemical parameters are related to poor prognosis of the disease and increase in the carcinogenic process. this study evaluated the activity of enzyme superoxide dismutase and biochemical parameters related to zinc, and investigated the existence of correlation between these variables and the marker of oxidative stress in these patients. this was a case-control study with 66 women aged between 20 and 50 years old, distributed into: case group (women with breast cancer, n = 34) and control group (healthy women, n = 32). Zinc intake was analyzed by three-day food diary, using Nutwin software, version 1.5. Plasma and erythrocyte zinc concentrations were determined by flame atomic absorption spectrophotometry method (λ = 213.9). Superoxide dismutase activity was assessed by Griess colorimetric method, and plasma thiobarbituric acid reactive substances (TBARS) were analyzed. mean levels of zinc intake, superoxide dismutase and TBARS were higher than recommended for the study participants with statistical difference for enzyme superoxide dismutase (p < 0.05). Mean plasma and erythrocyte concentrations of zinc were reduced in both groups (p > 0.05). therefore, it can be assumed that zinc intake in women with breast cancer does not impact plasma and erythrocyte concentrations of this mineral. High superoxide dismutase activity in women with breast cancer may be due to a compensatory mechanism of regulation via oxidative stress found in this disease.

Micronutrient deficiencies in normal and overweight infants in a low socio-economic population in north-east Brazil

Background:Micronutrient deficiencies are the most prevalent form of malnutrition worldwide. Although commonly related to underweight, micronutrient deficiencies can occur in both normal and overweight children in medium- and low-income populations undergoing nutritional transition.Objective:To describe haemoglobin and micronutrient levels in infants from a low-income area in Brazil in relation to their weight-for-length Z-score.Methods:A cross-sectional survey was undertaken of 2–11-month-old infants in Laranjeiras, a small urban community in North-east-Brazil between April 2009 and February 2010. Anthropometry and assays for haemoglobin, ferritin, plasma zinc, copper and selenium and erythrocyte zinc and copper concentrations were investigated.Results:The total number of full-term infants born in the study period was 222, of whom 153 were available for the study. Three (2%) children were wasted, 98 (66%) were of normal weight, 37 (25%) were at risk of overweight and 11 (7%) were overweight or obese. Nearly all (97%) children had at least one micronutrient deficiency, 102 (67%) had anaemia, 86 (58%) and 100 (67%) had plasma and erythrocyte zinc deficiency, respectively, and 7 (5%) and 113 (76%) had plasma and erythrocyte copper deficiency, respectively. 138 (91%) children had selenium deficiency. Except for plasma zinc, the proportion of infants with micronutrient deficiencies did not differ by weight-for-length status.Conclusions:The increased risk of overweight and micronutrient deficiencies in this population highlights the need to address the double burden of excess weight with micronutrient deficiencies in medium- and low-income settings.

Pharmacological Treatment may Impair Mineral Status in Blood

Hematological and biochemical blood parameters are rather stable in healthy subjects. However, there are many factors that can influence mineral status in blood, including diseases, diet, and drugs. It has been found that several medicines can alter both mineral concentrations and other mineral-status-related parameters in blood. In experimental and human studies, it has been shown that hypotension therapy disturbs zinc status in the body [1]. Some of our results suggest that indapamide and amlodipine treatment can decrease zinc concentration in serum and erythrocytes. Moreover, the decrease in zinc is accompanied by an increase in glucose serum levels [2]. In our experimental study, we observed that treatment with indapamide and amlodipine was associated with increased red blood cell counts and hematocrit values in the serum of spontaneously hypertensive rats [3]. In patients, high hematocrit could reflect the increase in red blood cell mass resulting from the reduction in plasma volume due to treatment with thiazide-type diuretics. Long-term therapy with captopril and enalapril may lead to zinc depletion in erythrocytes and monocytes. Preliminary data suggest that indapamide can cause a slight elevation in blood calcium levels. Several results indicate that loop diuretics, especially furosemide, reduce serum calcium and magnesium levels. It has also been observed that beta-blockers may induce hypocalcemia and hypomagnesemia [4]. Antiepileptic therapy with valproic acid may cause abnormalities in serum copper concentration. Some authors have found that therapy with valproic acid can diminish copper levels in erythrocytes and serum in epileptic patients [5,6]. Nonsteroidal anti-inflammatory drugs, when taken regularly, may cause bleeding from the gastrointestinal tract and iron loss with the blood. The use of aspirin and other medicines belonging to this group of drugs may therefore increase the risk of iron deficiency, which can be identified as a low hemoglobin and serum ferritin concentration [4,7]. In patients with digoxin therapy, a decrease in intracellular magnesium levels and a relatively low level of magnesium in serum were observed [8]. The long-term use of corticosteroids, cisplatin, cyclosporine is also associated with a depletion of magnesium in the serum and an increase in the risk of hypomagnesemia [4,9]. It is known that dietary restriction may impair mineral status; however, pharmacological treatment of obesity may also alter the concentration of minerals in the blood. In our clinical study, we found that 12 weeks of sibutramine therapy decreases zinc and increases magnesium concentrations in the serum, leading to mineral imbalances in obese women [10]. Oral contraceptives (OCs) are among the most commonly used drugs in developed countries. One of the side effects of this group of drugs is their influence on the mineral status in women. In several studies, it was observed that the use of oral contraceptives is associated with decreased zinc, magnesium, and selenium serum concentrations, and with increased copper levels in serum. It has also been found that oral contraceptives can increase ferritin and iron levels, TIBC, and mean corpuscular hemoglobin in serum, while decreasing red blood cells and hematocrit in whole blood in women. The results of human studies suggest that the effect of OCs on mineral status can vary with the form, dose, concomitant agents, and patient characteristics [4,11]. The mechanisms behind the observed interactions between drugs and minerals cannot always be explained. Some may be associated with changes in the excretion of minerals in the urine. Drugs may also influence the absorption and/or distribution of minerals in the body [4 ]. In conclusion, many drugs influence mineral status in the blood. Pharmacological treatment may require the monitoring of mineral concentrations in blood. Moreover, the interpretation of the results of morphological and biochemical analyses in blood requires a consideration of the drugs being used by the patient.

Effect of zinc supplementation on superoxide dismutase activity in patients with ulcerative rectocolitis.

Ulcerative rectocolitis is characterized by diffuse mucosal inflammation and oxidative stress. Thus, the organism activates the antioxidant defence system in an attempt to reduce the excessive production of reactive oxygen species or neutralize them. This study evaluated the effect of zinc supplementation on the activity of the enzyme superoxide dismutase (SOD) in patients with ulcerative rectocolitis. The study included 24 patients, aged between 20 and 59 years and diagnosed with ulcerative rectocolitis, in the remission stage of the disease, who were divided into two groups: experimental - deficient in zinc (n=12) and control - normal or high zinc (n=12). Only the first group underwent supplement intervention, in the form of zinc gluconate (30 mg Zn/day), taken daily in the morning, fasted for 60 days. Plasma and erythrocyte zinc concentrations were determined by flame atomic absorption spectrophotometer. The erythrocyte SOD activity was determined in vitro according to the methodology recommended by the manufacturer Randox. Zinc supplementation caused a significant increase in the plasma concentrations of the mineral, and showed a significant reduction in erythrocyte zinc, remaining within normal limits. The SOD activity was high in patients of both the experimental and control groups, with no difference after supplementation. This study demonstrates that zinc supplementation improves the homeostatic condition of the mineral, with no change in SOD activity, as a marker of oxidative stress in patients with ulcerative rectocolitis.

The influence of selected antihypertensive drugs on zinc, copper, and iron status in spontaneously hypertensive rats

Mineral homeostasis in hypertensive patients may be affected by hypotensive drugs. The aim of this study was to assess the influence of selected antihypertensive drugs on mineral homeostasis in a rat model of hypertension. Eight-week-old male spontaneously hypertensive rats (SHRs) were treated with perindopril, metoprolol, indapamide, amlodipine, or no drug for 45 days. In another experiment, the SHRs were treated with indapamide or amlodipine in the presence of zinc and copper gluconate supplement. Lipids, glucose, and insulin levels along with superoxide dismutase and catalase activities were assayed in serum. Iron, zinc, and copper concentrations in serum, erythrocytes, and tissues were determined using the flame atomic absorption spectrometry. Blood pressure was measured using a tail-cuff plethysmograph. Treatment with indapamide and amlodipine was found to significantly lower zinc levels in serum, erythrocytes, livers, and spleens of the SHRs, as well as copper levels in the kidneys, compared with the control no-drug group. A markedly higher concentration of glucose was found in the indapamide-treated rats. Supplementing the indapamide-treated SHRs with zinc and copper gluconate resulted in a significant decrease in both systolic and diastolic blood pressure, and also lowered serum glucose and triglyceride concentrations and HOMA (homeostasis model assessment-insulin resistance) values. The results show that indapamide and amlodipine disturb zinc and copper homeostasis in SHRs. Supplementation with zinc and copper restores mineral homeostasis in SHRs treated with indapamide and amlodipine, and also corrects metabolic imbalances while improving the antihypertensive efficiency of indapamide.

The beneficial effects of rosuvastatin are independent of zinc supplementation in patients with atherosclerosis

BackgroundStatins have multiple antiatherosclerotic effects, but can reduce blood plasma concentrations of minerals, including zinc. As zinc possesses antiinflammatory and antioxidant effects, low zinc status can promote injuries or inadequate tissue repair in endothelial cells. Metallothionein (MT) expression might modulate responses induced by statins in patients with atherosclerosis. However, research regarding mineral status and the use of statins is scarce. This study evaluated the effects of zinc supplementation on zinc status and expression of the zinc-dependent MT1F and MT2A genes in patients with atherosclerosis treated with rosuvastatin. MethodsA double-blind, randomized clinical trial was performed with 54 participants treated with 10mg rosuvastatin for 4 months with or without zinc supplementation (30mg/day). Diet, lipid profile, high-sensitivity reactive protein C (hs-CRP), plasma and erythrocyte zinc concentrations, erythrocyte superoxide dismutase (SOD) activity, and MT1F and MT2A genes expression were analyzed before and after intervention. ResultsRosuvastatin therapy was effective in reducing low- and non-high-density lipoprotein, total cholesterol, triglycerides, and hs-CRP levels, independent of zinc supplementation. Additionally, zinc treatment had no effect on SOD enzyme activity (P=0.201), plasma (P>0.671) and erythrocyte (P>0.123) zinc concentrations, or the pattern of MT1F and MT2A genes expression (P=0.088 and P=0.229, respectively). ConclusionsThe effectiveness of rosuvastatin treatment is independent of the effects of zinc supplementation. Moreover, rosuvastatin treatment did not have a significant impact on zinc status or MT1F and MT2A genes expression in patients with atherosclerosis.

Micronutrient Status of Children Receiving Prolonged Enteral Nutrition

Background and Aims: The aim of this study was to assess the micronutrient status of children receiving prolonged enteral nutrition. Methods: This cross-sectional single-center study included all 64 children (median age 6.8 years) receiving enteral nutrition providing >50% of daily energy intake for more than 6 months (median duration of enteral nutrition 43 months). The characteristics of the patients and mode of enteral nutrition were recorded. The concentrations of iron, zinc, copper, selenium and vitamins A, D, E and C were measured in plasma. Results: Twelve children (19%) had iron deficiency. A high 25-hydroxyvitamin D concentration was recorded in 20% of the children, but none had associated hypercalcemia. Fifty-two children (81%) had low zinc concentrations in both plasma and erythrocytes. Plasma zinc, calcium, phosphorus and vitamin D concentrations were significantly lower in children receiving fiber supplementation. Abnormal micronutrient concentrations were found more frequently in the children receiving fiber supplementation. No other predisposing factors were associated with micronutrient deficiencies. Conclusion: Long-term enteral nutrition can lead to micronutrient deficiencies in children, whose micronutrient concentrations may require regular checking. Fiber supplementation might reduce the bioavailability of zinc, calcium, phosphorus and vitamin D.

Enzyme activity of superoxide dismutase and zincemia in women with preeclampsia.

Preeclampsia is a complex syndrome of unknown aetiologic origin. It is characterized by the clinical triad of hypertension, edema and protenuria. Current concepts of the genesis of preeclampsia include endothelial dysfunction and oxidative stress. This study assessed the relationship between the activity of superoxide dismutase, the zincemia and the preeclampsia. A case-control study was carried out with 94 women, age between 17 and 44 years, which were divided in two groups: women with preeclampsia (n = 44) and control group women with normal pregnancy (n = 50). The activity of superoxide dismutase enzyme was determined according to Ransod kit. Zinc concentrations in plasma and erythrocytes were determined using the flame atomic absorption spectrophotometry technique, both determined before delivery and during puerperium. Student's t-test and the paired t-test were used for statistical analysis, and significance was established at p < 0.05. The study revealed plasma hypozincemia more pronounced in women with severe preeclampsia (p < 0.05). This behavior was not observed in erythrocytes, whose concentrations remained stable, before delivery and puerperium in women with preeclampsia and normal pregnancy. The antioxidant activity of the enzyme superoxide dismutase was found elevated in women with and without preeclampsia (p>0.05), with significant reduction in activity in the postpartum period (p < 0.05) in both groups studied (p>0.05). This study shows there are alterations in biochemical parameters of zinc in women with preeclampsia. The activity of superoxide dismutase shows that this marker cannot be used to predict the evolution of the disease.