Selenium biomarkers and miR-7-5p in overweight/obese women.

INTRODUCTION: Chronic low-grade inflammation and oxidative stress are pivotal contributors to the metabolic complications associated with obesity. Selenoprotein P (SELENOP) and glutathione peroxidase 1 (GPx1) are selenoproteins involved in the reduction of reactive oxygen species and pro-inflammatory cytokines levels. Nutritional epigenomics revealed the interaction of microRNAs and nutrients with an important impact on metabolic pathways involved in obesity. However, the knowledge regarding the influence of microRNA on selenium biomarkers and its impact on metabolic pathways related to obesity remains scarce. Thus, the aim of this study was to investigate the association of plasma miR-7-5p expression with selenium and inflammatory biomarkers in women with overweight/obesity. MATERIAL AND METHODS: Anthropometric evaluations were performed and blood samples were collected for the analysis of fasting glucose, insulin, inflammatory and selenium biomarkers, and miR-7-5p expression in 54 women with overweight/obesity. Gene expression of SELENOP and GPX1 were evaluated in peripheral mononuclear blood cells. RESULTS: This study observed a negative correlation between SELENOP levels and miR-7-5p (rho = -0.350; p = 0.018). Additionally, it was observed that body fat (OR = 0.737; p = 0.011), age (OR = 1.214; p = 0.007), and miR-7-5p (OR = 0.990; p = 0.015) emerged as significant predictors of SELENOP levels. CONCLUSIONS: In conclusion, we observed a significant inverse association between miR-7-5p expression and SELENOP concentration in overweight/obese women, suggesting that age and percentage of body fat are also associated. TRIAL REGISTRATION NUMBER: Brazilian Registry of Clinical Trials (ReBEC) number RBR-2nfy5q.

Plasma Concentration of Essential and Toxic Trace Elements After Brazil Nut Intake: Results from a Randomized Controlled Trial.

Brazil nut (BN) is a good source of essential nutrients, but little is known about the content of other components, such as toxic elements. Moreover, the high consumption of BN could probably contribute to increased levels of toxic and essential elements in the blood. Thus, this study aimed to evaluate the concentration of essential and toxic trace elements in BN and their concentration in plasma of obese women after regular intake of BN. A randomized controlled clinical trial was carried out with 55 subjects that were randomly assigned to either the Brazil nut group (BN) (n = 29) or the control group (CO) (n = 26) and followed up for 2 months. The BN group consumed one unit of Brazil nut per day, and the CO group did not receive any intervention. The concentration of essential elements (zinc, copper, manganese, and cobalt) and toxic (barium, lead, and cadmium) in BN samples and plasma of obese women (before and after the intervention) were determined by inductively coupled plasma mass spectrometry. Barium followed by copper, and manganese were the trace elements present in higher amounts in Brazil nuts. After the BN intervention period was observed an increase in plasma cadmium (p = 0.002) and a reduction of plasma manganese (p < 0.001) levels. In conclusion, our findings suggest that the regular consumption of BN from the Brazilian Amazon rainforest contributes to the intake of essential trace elements and can be considered safe regarding the content of heavy metals.

Evaluation of biomarkers related to zinc nutritional status, antioxidant activity and oxidative stress in rheumatoid arthritis patients.

BACKGROUND: Oxidative stress (OS) is an important process related to the pathophysiology of rheumatoid arthritis and can be increased by the low intake of antioxidants. Zinc (Zn) is an important antioxidant trace-element for human health and the assessment of the nutritional status of this micronutrient in these patients is of relevance. AIM: This study aimed to evaluate Zn nutritional status in rheumatoid arthritis patients and its relation to OS. METHODS: A case-control study was carried out with 51 patients diagnosed with rheumatoid arthritis (RA group) recruited in Hospital São Paulo (São Paulo, Brazil) and 55 healthy women (CO group) from the campus of the University of São Paulo. Blood and 24-hour urine collection were used for biochemical parameters related to Zn status and OS. The assessment of dietary Zn was performed by three 24-hour dietary recalls. RESULTS: The RA group presented significative low Zn intake (p < 0.001) and plasma concentration (p = 0.040) of this mineral compared to the CO group. However, both groups were Zn deficient and the disease activity (DAS28 score) for RA patients did not influence Zn biomarkers. In addition, the antioxidant enzymes (superoxide dismutase and glutathione peroxidase) activity and the urinary 8-isoprostanes were reduced in RA patients. CONCLUSION: The evaluation of dietary intake and biochemical biomarkers indicates that rheumatoid arthritis patients are zinc deficient and have increased OS.

Zinc nutritional status influences ZnT1 and ZIP4 gene expression in children with a high risk of zinc deficiency.

INTRODUCTION: Subclinical deficiency of zinc is associated with impairment of immune system function, growth, and cognitive development in children. Although plasma zinc is the best available biomarker of the risk of zinc deficiency in populations, its sensitivity for early detection of deficiency is limited. Therefore, we aimed to investigate zinc deficiency among preschool children and its relationship with whole blood gene expression of zinc transporters ZIP4 and ZnT1. MATERIAL AND METHODS: This cross-sectional study included 139 children aged 32-76 months enrolled in philanthropic day-care centers. We performed an anthropometric evaluation, weighed food record and dietary record for dietary assessment, blood sample collection for zinc, and whole blood gene expression analyses of ZnT1 (SLC30A1) and ZIP4 (SLC39A4). RESULTS: Zinc deficiency was observed in 26.6 % of the children despite adequate zinc intake and a phytate:zinc molar ratio < 18. Usual zinc intake did not affect whole blood gene expression of zinc transporters, but zinc status influenced ZnT1 and ZIP4 whole blood mRNA. Children with zinc deficiency exhibited 37.1 % higher ZnT1 expression and 45.3 % lower ZIP4 expression than children with adequate zinc (p < 0.05). CONCLUSION: Children with plasma zinc deficiency exhibited higher expression of ZnT1 and lower expression of ZIP4 in whole blood mRNA, reinforcing the existence of strong regulation of mineral homeostasis according to the nutritional status, indicating that this analysis may be useful in the evaluation of dietary interventions.

Increasing Selenium and Vitamin E in Dairy Cow Milk Improves the Quality of the Milk as Food for Children.

In this study, we investigated the beneficial effects of milk biofortified with antioxidants on the health of children. Two experiments were conducted: experiment one evaluated the milk of 24 Jersey dairy cows (450 ± 25 kg of body weight (BW); 60 ± 30 days in milk dry matter intake (DIM)) given different diet treatments (CON = control diet; COANT = diet with vitamin E and selenium as antioxidants; OIL = diet with sunflower oil; and OANT = diet with sunflower oil containing more vitamin E and selenium as antioxidants), and experiment two evaluated the effect of the milk produced in the first experiment on the health of children (CON = control diet; COANT = diet with vitamin E and selenium as antioxidants; OIL = diet with sunflower oil; OANT = diet with sunflower oil containing more vitamin E and selenium as antioxidants; and SM = skim milk). One hundred children (8 to 10 years old) were evaluated in the second experiment. Blood samples were collected at 0 days of milk intake and 28 and 84 days after the start of milk intake. The cows fed the COANT and OANT diets showed greater selenium and vitamin E concentrations in their milk (p = 0.001), and the children who consumed the milk from those cows had higher concentrations of selenium and vitamin E in their blood (p = 0.001). The platelet (p = 0.001) and lymphocyte (p = 0.001) concentrations were increased in the blood of the children that consumed milk from cows fed the OANT diet compared to those in the children that consumed SM (p = 0.001). The children who consumed milk from cows fed the OIL diet treatment had increased concentrations of low density lipoprotein (LDL) and total cholesterol in their blood at the end of the supplementation period compared to children who consumed SM. The results of this study demonstrate that the consumption of biofortified milk increases the blood concentrations of selenium and vitamin E in children, which may be beneficial to their health.

Brazil nut intake increases circulating miR-454-3p and miR-584-5p in obese women.

The Brazil nut is an excellent source of selenium (Se), an essential micronutrient for human health. In this study, we hypothesized that Brazil nut intake modulates circulating microRNAs (miRNAs) in obese women and aimed to evaluate the effects of this nut intake on circulating miRNAs in women with obesity or metabolic syndrome (MetS). A randomized controlled clinical trial was conducted on 54 subjects recruited from the Clinical Hospital in São Paulo, Brazil. Patients were randomly assigned to 2 groups: a Brazil nut group (BN group, n = 29) and a control group (CO group, n = 25); both were monitored for 2 months. BN group members were instructed to consume 1 Brazil nut (approximately 1261 µg/Se) per day; CO group members were instructed not to consume any. Biochemical parameters related to Se status and 25 circulating miRNAs in plasma were evaluated in all patients both at baseline and after 2 months. Expression levels of 2 miRNAs (miR-454-3p and miR-584-5p) were significantly increased after Brazil nut intake. To investigate the effect of MetS on circulating miRNAs at baseline, we performed comparisons between women with MetS (n = 23) and women without MetS (others, n = 31). Circulating miR-375 levels were significantly lower (P = .012) in women with MetS. In conclusion, our findings suggested that a daily intake of 1 Brazil nut increased circulating miR-454-3p and miR-584-5p expression levels in obese women, and our network analysis indicated a link between Se intake, vitamin D metabolism, and calcium homeostasis.

Consumption of Brazil nuts with high selenium levels increased inflammation biomarkers in obese women: A randomized controlled trial.

OBJECTIVE: Increased inflammatory response is an important factor in the pathophysiology of obesity. The mineral selenium (Se), of which one of the main food sources is the Brazil nut, has important antioxidant and anti-inflammatory functions through the action of selenoproteins. Thus, the evaluation of the influence of this micronutrient in this context is of great relevance. The aim of this study was to evaluate the effects of Brazil nut intake with high Se concentrations on inflammatory biomarkers and its relation to Se status in obese women. METHODS: A randomized controlled clinical trial was carried out with 55 women recruited at Clinical Hospital in São Paulo, Brazil. Patients were randomly assigned to either the Brazil nut group (BN) or the control group (CO) and followed up for 2 mo. The BN group consumed 1 unit/d of Brazil nuts (∼ 1261 µg/Se); the CO group did not receive any intervention. At baseline and after 2 mo, analysis of biochemical parameters related to Se status, oxidative stress, and inflammatory biomarkers were performed. RESULTS: At baseline, both groups did not present Se deficiency. In the BN group, a significant increase (P < 0.05) in all Se biomarkers and in gene expression of several proinflammatory parameters (interleukin-6, tumor necrosis factor-α, and Toll-like receptors 2 and 4) were observed after the intervention period. No changes were observed for the CO group. CONCLUSION: Although there were no changes in plasma inflammatory biomarkers levels, a significant increase in gene expression may be an indication of a proinflammatory stimulus in obesity, induced by the consumption of Brazil nuts with high Se levels.

Inflammatory process of patients receiving parenteral nutrition is not exclusively responsible for low selenium and glutathione peroxidase levels.

OBJECTIVE: The aim of this study was to verify if the selenium status of patients residing in locations with selenium-poor soil who receive parenteral nutrition (PN) without selenium supplementation is associated with the inflammatory process. METHODS: This was a prospective cohort study with hospitalized patients who started PN. The analyzed biochemical tests were plasma selenium, glutathione peroxidase (GPx), C-reactive protein, prealbumin, albumin, creatinine, lymphocytes, total cholesterol, high-density lipoprotein, and triglycerides. RESULTS: Seventy-seven patients with a mean age of 56.2 ± 15.7 y were studied. Most of them used PN as a result of clinical issues (70.1%) such as, gastric, renal, or hematologic neoplasia; gastrointestinal dysfunction; pancreatitis; sepsis; trauma without surgical needs; chylothorax; and fistula not related to surgical procedure. There were low levels of plasma selenium (98.7%) and GPx (60%) and elevated C-reactive protein (98.5%) in most cases. At the beginning of PN there was no correlation between selenium and laboratory tests (P > 0.05). At the second evaluation (seventh day of PN), there was a positive correlation of selenium levels with lymphocyte levels (r = 0.36; P = 0.04). After 2 wk of PN, there was a statistically significant correlation between selenium and GPx (r = 0.70; P = 0.02). CONCLUSIONS: Very low values of selenium and GPx from the beginning of PN were identified. The correlation of selenium levels with GPx in only 14 d of PN, regardless of inflammation, may reflect a critical selenium status, mainly because the correlation was verified after the acute phase. Therefore it is important to emphasize that supplementation should be started from the beginning of PN, especially in regions with selenium-deficient soil.

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 ß-cell function (HOMA- ß) 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.

Mineral status and superoxide dismutase enzyme activity in Alzheimer's disease.

The study evaluated the dietary intake of zinc and copper, as measured by plasma and erythrocyte concentrations, the Cu/Zn ratio and measure the erythrocyte superoxide dismutase enzyme (eSOD) activity and the relationship between these markers and the degree of dementia in elderly individuals with and without Alzheimer's Disease (AD). A total of 93 elderly people aged 60-94 years were divided into two groups: with AD (n=44) and without AD (n=49). The NINCDS-ADRDA criteria were used for diagnosing AD, and dementia staging was determined using the Clinical Dementia Rating (CDR) scale. The dietary intake of Zn and Cu was obtained from a standard 3-day food record. Plasma and erythrocyte concentrations of the minerals were determined by flame atomic absorption spectrophotometry and by measuring eSOD activity in an automatic biochemical analyzer. The results showed dietary intake of Zn and Cu above the reference values with no differences observed between the two groups (p>0.05). Plasma and erythrocyte normocupremia as well as alteration in the Zn pool, with its reduced plasma concentrations and high in the erythrocytes, were observed in both groups (p>0.05). The plasma Cu/Zn ratio were not significantly different in patients with and without AD (p>0.05). The eSOD activity was high in both patient groups (p>0.05). However, among elderly patients with AD there was a positive correlation between this marker and dementia severity. According to our study results, we conclude that plasma and erythrocyte concentrations of Cu and Zn, as well as Cu/Zn ratio among elderly individuals is not related to Alzheimer's Disease. However, antioxidant activity of eSOD is associated with dementia severity.

Influence of selenium supplementation on patients with inflammation: A pilot double blind randomized study.

OBJECTIVE: The aim of the study was to analyze the effect of selenium supplementation on patients with inflammation receiving PN. METHODS: This double-blind randomized study included 20 hospitalized patients experiencing an inflammatory process while being fed by PN, who were monitored in three stages: first 72 h (0), day 7 (1), and day 14 (2) of PN. The supplemented patients group (G+S) received 60 µg/d (0.75 µmol) of selenium as selenious acid which was added to the PN bag. The nonsupplemented group (G-S) did not receive selenium. The concentration range of 84 to 100 µg/L (1.07-1.27 µmol/L) was used as a reference of plasma selenium. RESULTS: The study included 20 patients (8 G+S and 12 G-S) mainly diagnosed with cancer and/or sepsis. Most of them were hospitalized in the intensive care unit and were receiving PN for clinical reasons. Plasma selenium was greater in the G+S than in the G-S (P = 0.05) in two stages (0 and 1). Since the start of assessment, C-reactive protein (CRP) levels were elevated; however, there was no statistical difference in CRP values between groups (P > 0.05). There was no significant change of glutathione peroxidase over time or between groups (P > 0.05). CONCLUSION: The selenium concentration was greater in the G+S than in the G-S, acting independently from CRP behavior. However, supplementation was not enough to reach the reference values.

[Is plasma selenium correlated to transthyretin levels in critically ill patients?]

BACKGROUND: Selenium is an essential trace element, but critically ill patients using total parenteral nutrition (PN) do not receive selenium because this mineral is not commonly offered. Threfore, the eval uation of plasma selenium levels is very important for treating or preventing this deficiency. Recent studies have shown that transthyretin may reflect the selenium intake and could be considered a biomarker. However, this issue is still little explored in the literature. OBJECTIVE: This study aims to investigate the correlation of transthyretin with the plasma selenium of critically ill patients receiving PN. METHOD: This was a prospective cohort study with 44 patients using PN without selenium. Blood samples were carried out in 3 stages: initial, 7th and 14th day of PN. In order to evaluate the clinical condition and the inflammatory process, albumin, C-reactive protein (CRP), transthyretin, creatinine and HDL cholesterol levels were observed. To assess the selenium status, plasma selenium and glutathione peroxidase (GPx) in whole blood were measured. Descriptive analyses were performed and the ANOVA, Mann-Whitney and Spearman's coefficient tests were conducted; we assumed a significance level of 5%. RESULTS: A positive correlation of selenium with the GPx levels (r = 0.46; p = 0.03) was identified. During two weeks, there was a positive correlation of transthyretin with plasma selenium (r = 0.71; p = 0.05) regardless of the CRP values. CONCLUSION: Transthyretin may have reflected plasma selenium, mainly because the correlation was verified after the acute phase.

Selenium Status in Patients with Turner Syndrome: a Biochemical Assessment Related with Body Composition.

Studies about selenium status in patients with Turner syndrome (TS) are non-existent in the literature. The aim of this study was to evaluate selenium status in patients with TS, while considering the different ages of the studied population and the relation with body composition. In total, 33 patients with TS were evaluated and grouped according to their developmental stages (children, adolescents, and adults). Selenium concentrations in their plasma, erythrocytes, urine, and nails were determined by using hydride generation atomic absorption spectrometry and erythrocyte glutathione peroxidase activity were measured by using Randox commercial kits. Additionally, height, weight, body fat percentage, waist circumference, and waist-height ratio were measured to characterize the patients. No differences in the selenium concentrations in the plasma, erythrocyte, urine, and nails or in the glutathione peroxidase activity were observed among the age groups (p > 0.05). The evaluated selenium levels were less than the established normal ones. The patients with larger waist circumference, body fat percentage, body mass index, and waist-height ratio showed lower glutathione peroxidase enzyme activity (p = 0.023). The present study shows that most patients with TS are deficient in selenium and that those with a greater accumulation of body fat have a lower GPx activity.

Effects of Brazil nut consumption on selenium status and cognitive performance in older adults with mild cognitive impairment: a randomized controlled pilot trial.

PURPOSE: Oxidative stress is closely related to cognitive impairment, and the antioxidant system may be a potential therapeutic target to preserve cognitive function in older adults. Selenium plays an important antioxidant role through selenoproteins. This controlled trial aimed to investigate the antioxidant and cognitive effects of the consumption of Brazil nuts, the best selenium food source. METHODS: We enrolled 31 older adults with mild cognitive impairment (MCI) who were randomly assigned to ingestion of Brazil nuts or to the control group. Participants of the treatment group consumed one Brazil nut daily (estimated 288.75 µg/day) for 6 months. Blood selenium concentrations, erythrocyte glutathione peroxidase (GPx) activity, oxygen radical absorbance capacity, and malondialdehyde were evaluated. Cognitive functions were assessed with the CERAD neuropsychological battery. RESULTS: Eleven participants of the treated group and nine of the control group completed the trial. The mean age of the participants was 77.7 (±5.3) years, 70 % of whom were female. We observed increased selenium levels after the intervention, whereas the control group presented no change. Among the parameters related to the antioxidant system, only erythrocyte GPx activity change was significantly different between the groups (p = 0.006). After 6 months, improvements in verbal fluency (p = 0.007) and constructional praxis (p = 0.031) were significantly greater on the supplemented group when compared with the control group. CONCLUSION: Our results suggest that the intake of Brazil nut restores selenium deficiency and provides preliminary evidence that Brazil nut consumption can have positive effects on some cognitive functions of older adults with MCI.

The hypolipidemic and pleiotropic effects of rosuvastatin are not enhanced by its association with zinc and selenium supplementation in coronary artery disease patients: a double blind randomized controlled study.

OBJECTIVE: Statins treatment may modify the levels of zinc and selenium, minerals that can improve vascular function and reduce oxidative damage and inflammation in atherosclerotic patients. This study aimed to evaluate the effects of rosuvastatin, alone or associated with zinc and selenium supplementation, on lipid profile, antioxidant enzymes and mineral status in coronary artery disease patients. MATERIAL AND METHODS: A double-blind randomized clinical trial was performed in which patients (n = 76) were treated with 10 mg rosuvastatin over 4 months associated or not with zinc (30 mg/d) and selenium (150 µg/d) supplementation. The following parameters were analyzed before and after the intervention: anthropometric measurements, lipid profile, high sensitivity C-reactive protein (hs-CRP), electronegative low density lipoprotein (LDL(-)) concentrations, activities of glutathione peroxidase (GPx), superoxide dismutase (SOD), zinc and selenium concentrations in blood plasma and erythocytes. Significance was determined using an α of 5% (two-tailed). RESULTS: We found that rosuvastatin therapy was efficient in reducing total cholesterol, LDL-cholesterol, non-HDL cholesterol, triglycerides, and hs-CRP independently of mineral supplementation. Neither treatment was associated with significant changes in LDL(-). Similarly, the antioxidant enzymes GPx and SOD activity were unchanged by treatments. Neither treatment was associated with significant differences in concentrations of zinc or selenium in blood plasma and erythocytes of studied groups. CONCLUSION: Rosuvastatin treatment did not affect zinc and selenium levels in coronary artery disease patients. The zinc and selenium supplementation at doses used in this study did not change lipid profile or SOD and GPx activity in patients receiving rosuvastatin. Further studies should be focused on testing alternative doses and supplements in different populations to contribute for a consensus on the ideal choice of antioxidants to be used as possible complementary therapies in atherosclerotic patients. TRIAL REGISTRATION: ClinicalTrials.gov NCT01547377.

Selenium plasma levels in hemodialysis patients: comparison between North and Southeast of Brazil.

INTRODUCTION: Patients with chronic kidney disease present selenium (Se) plasma deficiency which is an essential trace element with important biological functions and, the best known biological role is attributed to its presence in the antioxidant enzyme, glutathione peroxidase (GPx). The Se content of foods depends on soil and some authors have suggested that Amazon soil (North Brazilian region) has high Se concentrations when compared to other regions of Brazil. OBJECTIVE: The objective of this work was to compare the Se status in hemodialysis (HD) patients from North and Southeast of Brazil. METHODS: Thirty-eight patients from Southeast region (22 men and 16 women, 15% diabetic, 53.5 ± 26.4 yrs) were compared to 40 patients from North region (28 men and 12 women, 22.5% diabetic, 63.5 ± 11.9 yrs). Se in plasma was determined through atomic absorption spectrophotometry with hydride generation. RESULTS: The plasma Se levels in patients from Southeast region were significantly lower (17.5 ± 11.9 µg/L) when compared to patients from the North (37.1 ± 15.8 µg/L) (p < 0.001). However, both patient groups presented low Se plasma levels when compared to recommended values (60- 120 µg/L). There was no correlation between plasma Se levels and analyzed parameters. CONCLUSION: We concluded that patients from North (Amazon) region present higher plasma Se levels when compared to the patients from Southeast of Brazil. However, independently of the region, HD patients presented Se deficiency.

Selenium plasma levels in hemodialysis patients: Comparison between North and Southeast of Brazil / Níveis de selênio plasmático em pacientes em hemodiálise: Comparação entre Norte e Sudeste do Brasil

Introduction: Patients with chronic kidney disease present selenium (Se) plasma deficiency which is an essential trace element with important biological functions and, the best known biological role is attributed to its presence in the antioxidant enzyme, glutathione peroxidase (GPx). The Se content of foods depends on soil and some authors have suggested that Amazon soil (North Brazilian region) has high Se concentrations when compared to other regions of Brazil. Objective: The objective of this work was to compare the Se status in hemodialysis (HD) patients from North and Southeast of Brazil. Methods: Thirty-eight patients from Southeast region (22 men and 16 women, 15% diabetic, 53.5 ± 26.4 yrs) were compared to 40 patients from North region (28 men and 12 women, 22.5% diabetic, 63.5 ± 11.9 yrs). Se in plasma was determined through atomic absorption spectrophotometry with hydride generation. Results: The plasma Se levels in patients from Southeast region were significantly lower (17.5 ± 11.9 μg/L) when compared to patients from the North (37.1 ± 15.8 μg/L) (p < 0.001). However, both patient groups presented low Se plasma levels when compared to recommended values (60- 120 μg/L). There was no correlation between plasma Se levels and analyzed parameters. Conclusion: We concluded that patients from North (Amazon) region present higher plasma Se levels when compared to the patients from Southeast of Brazil. However, independently of the region, HD patients presented Se deficiency. .

Introdução: Pacientes com Doença Renal Crônica apresentam deficiência de selênio (Se), um elemento essencial, com importantes funções biológicas, como a de ser componente da enzima antioxidante glutationa peroxidase (GPx). A concentração de Se nos alimentos depende de sua concentração no solo e autores relatam que o solo da Amazônia possui elevados níveis de Se. Objetivo: O objetivo do trabalho foi comparar o estado nutricional do Se em pacientes em hemodiálise (HD) das regiões Norte e Sudeste do Brasil. Métodos: Trinta e oito pacientes da região Sudeste (22 homens e 16 mulheres, 15% diabéticos, 53,5 ± 26,4 anos) foram comparados com 40 pacientes da região Norte (28 homens e 12 mulheres, 22,5% diabéticos, 63,5 ± 11,9 anos). O Se no plasma foi determinado por espectrofotometria de absorção atômica por geração de hidretos acoplados a cela de quartzo. Resultados: Os níveis de Se dos pacientes em HD da região Sudeste foram significativamente menores (17,5 ± 11,9 μg/L) comparados aos pacientes da região Norte (37,1 ± 15,8 μg/L) (p < 0,001). Entretanto, ambos os grupos apresentaram níveis de Se abaixo da recomendação (60-120 μg/L). Não houve associação entre os níveis de Se e os parâmetros analisados. Conclusão: Com base nos resultados, concluímos que os pacientes da região Norte apresentaram elevados níveis de Se quando comparados com os pacientes da região Sudeste do Brasil. Entretanto, independentemente da região, ambos os grupos apresentaram deficiência com relação ao estado nutricional do Se. .

Selenium status and hair mercury levels in riverine children from Rondônia, Amazonia.

OBJECTIVE: Riverine communities in Rondônia State are exposed to high selenium (Se) content in their diet because of the high-selenium soils identified in the Amazon. However, the Amazonian population has a high mercury (Hg) exposure because this metal accumulates in the soil. Because children are more vulnerable to Hg toxicity, the aim of this study was to evaluate and correlate Se status and hair Hg levels in riverine children (aged 3-9 y) living in two different locations in Rondônia State: Demarcação area (DA) and Gleba do Rio Preto (GRP). METHODS: Se levels were assessed using hydride generation quartz tube atomic absorption spectroscopy; total hair Hg levels were assessed using cold vapor atomic absorption spectrometry. Dietary intake was evaluated through a 24-h food record and a food frequency questionnaire. RESULTS: Forty-two children participated in this study. Eighty-four percent of the children from DA showed low plasma Se. Conversely, all children from GRP presented plasma Se levels above the reference values. Forty-five percent of the children from DA presented low erythrocyte levels, and 55% of the children from GRP showed concentration in erythrocyte above the reference values. The mean Se intake was 41.8 µg/d in DA and 179.0 µg/d in GRP. High hair Hg levels were observed in children from both the DA and GRP (3.57 ± 1.86 and 6.24 ± 5.89, respectively). CONCLUSIONS: Children from both riverine communities are likely to present altered Se status according to their dietary intake. Additionally, these children are highly exposed to Hg, mainly through fish consumption, and the toxicity of this metal may cause metabolic damage.