Selenium Biomarkers and Their Relationship to Cardiovascular Risk Parameters in Obese Women.

A cross-sectional study was carried out with 210 women divided into a case group (obese, n = 84) and a control group (eutrophic, n = 126). Body weight, height, waist circumference (WC), and hip and neck circumference were measured and the waist-hip ratio and conicity index were calculated. Selenium in plasma, erythrocytes and urine, erythrocyte GPx activity, lipid profile, Castelli I and II indices, and systolic and diastolic blood (DBP) pressure were evaluated. Mean dietary selenium intake (µg/kg/day) and plasma and erythrocyte concentrations were lower in the obese group compared to the healthy group (p < 0.001). while urinary selenium concentrations were higher (p < 0.001). There was a statistical difference between groups regarding cardiovascular risk parameters: waist circumference, neck circumference, waist-hip ratio, conicity index, triacylglycerols (TGC), and lipoproteins rich in triacylglycerols (VLDL-c) (p > 0.05). There was a negative correlation between plasma selenium concentrations and total cholesterol (TC), non-high-density lipoprotein (non-HDL), low-density lipoprotein (LDL-c), and systolic blood pressure (SBP). Urinary selenium correlated negatively with waist circumference and hip circumference and positively with neck circumference, TC, TGC, high-density lipoprotein (HDL-c), non-HDL, and VLDL-c. There was a negative correlation between dietary selenium and waist circumference, waist-hip ratio, neck circumference, conicity index, non-HDL cholesterol, LDL-c, and Castelli indices I and II, as well as a positive correlation with HDL-c and diastolic blood pressure. Women with obesity present changes in their nutritional status related to selenium, as well as increased cardiovascular risk parameters. Thus, the positive role of selenium in protecting the risk of cardiovascular disease is likely.

Relationship Between Zinc, Selenium, and Magnesium Status and Markers of Metabolically Healthy and Unhealthy Obesity Phenotypes.

Our objective was to investigate the relationship between zinc, selenium, and magnesium status and markers of metabolically healthy and unhealthy obesity phenotypes. This was a cross-sectional study with 140 women: metabolically healthy obese women (n = 35), metabolically unhealthy obese women (n = 28), and normal-weight women (n = 77). We have calculated the body mass index, waist-hip ratio, waist-height ratio and some adiposity indices. Additionally, we evaluated endocrine-metabolic parameters and estimated the dietary intake of energy, macronutrients, zinc, selenium, and magnesium. The mineral concentrations in plasma, erythrocytes, and urine were assessed. In obese patients, there was a significant decrease in dietary zinc, selenium, and magnesium intake per kilogram of body weight, as well as lower mineral concentrations in both plasma and erythrocytes. Additionally, these patients exhibited higher urinary mineral levels compared to the control group, regardless of whether they had healthy or unhealthy phenotypes. We observed a significant correlation between deficiencies in zinc, selenium, and magnesium and obesity-associated metabolic disorders, including dyslipidemias and redox status disturbances. This study highlights a connection between deficiencies in zinc, selenium, and magnesium and metabolic disorders linked to obesity, including dyslipidemias, alterations in redox status, and thyroid hormonal dysfunction.

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.

Relationship Between Markers of Chronic Inflammation and Copper Nutritional Status in Obese Women.

Adipose tissue dysfunction causes the development of metabolic complications, such as low-grade chronic inflammation, which may to alter copper homeostasis in obese individuals. Thus, the objective of this study is to analyze the relationship between markers of chronic inflammation and copper nutritional status in obese women. Cross-sectional study involved women aged 20-50 years, divided into two groups: case (BMI > 35 kg/m2) and control (18.5 > BMI > 24.9 kg/m2). Plasma and erythrocyte copper concentrations were determined by inductively coupled plasma optical emission spectrometry (ICP-OES) method. Activity of superoxide dismutase (SOD) enzyme in the erythrocytes was determined with an automatic biochemical analyzer. Serum concentrations of interleukin (IL)-6, IL-8, IL-12, IL-10, and IL-1ß and tumor necrosis factor-alpha (TNF-α) were determined by using flow cytometer. Serum IL-6 concentrations were 105% higher in the case group compared to eutrophic women. Plasma copper concentrations were 20.5% higher, and erythrocyte copper concentrations were 23.5% lower in patients with obesity. In addition, erythrocyte SOD activity was 20% lower in obese participants when compared to eutrophic women. Our study identified significant negative correlation between the cytokines TNF-α and IL-10 and the SOD activity in the case group, suggesting a possible influence of chronic inflammation on copper distribution in obese individuals.

Prevalence of metabolic syndrome and its components in Brazilian adolescents: a systematic review and meta-analysis / Prevalência da síndrome metabólica e seus componentes em adolescentes brasileiros: uma revisão sistemática e metanálise

Abstract Objective: To determine the prevalence of metabolic syndrome (MS) and its components among Brazilian adolescents. Data source: Databases, such as LILACS, MEDLINE, and SciELO, were searched for original cross-sectional studies published between 2010 and 2021. The inclusion criteria were determined based on the mnemonic CoCoPop — Condition, Context, and Population: studies determining the prevalence of MS and its components (condition) in the general population of Brazilian adolescents, female and male (population), enrolled in public or private schools in rural or urban areas (context). Reviews, editorials, and articles that did not directly relate to the prevalence of MS or that included non-adolescent age groups or groups with specific health conditions (obesity/overweight and others) were excluded. Data synthesis: A total of 15 studies, including 43,227 adolescents, were identified. MS prevalence (95% confidence interval [95%CI]) was 2.9% (2.65-3.18) and 2.4% (1.90-2.90) (p<0.001) in males and females, respectively, by using the International Diabetes Federation (IDF) criteria. There was a significant difference in MS prevalence among Brazilian regions (Q=24.7; p<0.001). The lowest MS prevalence (95%CI) was determined for North Region of Brazil, 1.8% (1.52-2.13), and the highest for Northeast Region of Brazil, 2.9% (2.62-3.23). Regarding MS components, a higher prevalence (95%CI) was found for low high-density lipoprotein (HDL), 22.1% (12.49-36.17), followed by abdominal obesity, 11.0% (8.05-14.94), and arterial hypertension, 10.3% (7.84-13.48). Conclusions: This study allowed the determination of the prevalence of MS and the MS components in Brazilian adolescents, highlighting relevant aspects to be addressed on public health management.

RESUMO Objetivo: Determinar a prevalência da síndrome metabólica (SM) e seus componentes em adolescentes brasileiros. Fontes de dados: Realizaram-se buscas nas bases de dados Literatura Latino-Americana e do Caribe em Ciências da Saúde (Lilacs), Medical Literature Analysis and Retrieval System Online (Medline) e Scientific Electronic Library Online (SciELO) por estudos transversais originais publicados entre 2010 e 2021. Os critérios de inclusão foram determinados pelo Mnemônico CoCoPop — Condição, Contexto e População: estudos que determinam a prevalência de SM e seus componentes (condição) na população geral de adolescentes brasileiros, feminino e masculino (população), matriculados em escolas públicas ou privadas em áreas rurais ou urbanas (contexto). Revisões, editoriais, artigos não relacionados com a prevalência de SM ou que incluíssem grupos etários não adolescentes ou com condições de saúde específicas (obesidade/sobrepeso e outros) foram excluídos. Síntese dos dados: Quinze estudos, com 43.227 adolescentes, foram identificados. A prevalência de SM (intervalo de confiança — IC95%) no sexo masculino foi de 2,9% (2,65-3,18) e no feminino foi de 2,4% (1,90-2,90) (p<0,001), pelos critérios da Federação Internacional de Diabetes (IDF). Houve diferença significativa na prevalência de SM entre regiões brasileiras (Q=24,7; p<0,001). A menor prevalência de SM (IC95%) foi encontrada em região Norte, com 1,8% (1,52-2,13), e a maior na região Nordeste, com 2,9% (2,62-3,23). Em relação aos componentes da SM, maior prevalência (IC95%) foi encontrada para lipoproteína de baixa densidade (HDL) baixa (22,1%, 12,49-36,17), seguida de obesidade abdominal (11,0%, 8,05-14,94) e hipertensão arterial (10,3%, 7,84-13,48). Conclusões: Este estudo permitiu determinar a prevalência da SM e seus componentes em adolescentes brasileiros, destacando aspectos relevantes a serem abordados na gestão da saúde pública.

Prevalence of metabolic syndrome and its components in Brazilian adolescents: a systematic review and meta-analysis.

OBJECTIVE: To determine the prevalence of metabolic syndrome (MS) and its components among Brazilian adolescents. DATA SOURCE: Databases, such as LILACS, MEDLINE, and SciELO, were searched for original cross-sectional studies published between 2010 and 2021. The inclusion criteria were determined based on the mnemonic CoCoPop - Condition, Context, and Population: studies determining the prevalence of MS and its components (condition) in the general population of Brazilian adolescents, female and male (population), enrolled in public or private schools in rural or urban areas (context). Reviews, editorials, and articles that did not directly relate to the prevalence of MS or that included non-adolescent age groups or groups with specific health conditions (obesity/overweight and others) were excluded. DATA SYNTHESIS: A total of 15 studies, including 43,227 adolescents, were identified. MS prevalence (95% confidence interval [95%CI]) was 2.9% (2.65-3.18) and 2.4% (1.90-2.90) (p<0.001) in males and females, respectively, by using the International Diabetes Federation (IDF) criteria. There was a significant difference in MS prevalence among Brazilian regions (Q=24.7; p<0.001). The lowest MS prevalence (95%CI) was determined for North Region of Brazil, 1.8% (1.52-2.13), and the highest for Northeast Region of Brazil, 2.9% (2.62-3.23). Regarding MS components, a higher prevalence (95%CI) was found for low high-density lipoprotein (HDL), 22.1% (12.49-36.17), followed by abdominal obesity, 11.0% (8.05-14.94), and arterial hypertension, 10.3% (7.84-13.48). CONCLUSIONS: This study allowed the determination of the prevalence of MS and the MS components in Brazilian adolescents, highlighting relevant aspects to be addressed on public health management.

Participation of Magnesium in the Secretion and Signaling Pathways of Insulin: an Updated Review.

Several studies have demonstrated the participation of various minerals in mechanisms involving insulin. Magnesium, in particular, plays an important role in the secretion and action of this hormone. Therefore, this review aimed to examine the latest insights into the biochemical and molecular aspects of the participation of magnesium in insulin sensitivity. Magnesium plays a vital role in the activity of intracellular proteins involved in insulin secretion in ß-pancreatic cells, such as glucokinase, ATPase, and protein kinase C. In addition, evidence suggests that this mineral participates directly in insulin sensitivity and signaling in peripheral tissues, acting in the phosphorylation of the receptor tyrosine kinase and the insulin receptor substrates 1, insulin receptor substrates 2, phosphatidylinositol 3-kinase, and protein kinase B, and indirectly by reducing oxidative stress and chronic low-grade inflammation, which also lead to insulin resistance. Thus, magnesium deficiency is associated with glucose intolerance, while magnesium supplementation stimulates insulin secretion in pancreatic cells and improves insulin sensitivity in peripheral tissues. However, studies must consider assess short- and long-term nutritional status of mineral before performing intervention, the relevance of the balance of other nutrients that influence hormone secretion and sensibility, and health status of the assessed population.

Leptin and its relationship with magnesium biomarkers in women with obesity.

Some studies have demonstrated the participation of leptin in magnesium metabolism. On the other hand, there is evidence of the role of magnesium in the leptin intracellular signaling pathway. Therefore, the aim of this study was to investigate the existence of a relationship between serum leptin concentrations and magnesium biomarkers in women with obesity. Case-control study involving 108 women aged between 20 and 50 years, divided into two groups: obese (n = 52) and control (n = 56). Body weight, height and waist circumference, body mass index, dietary magnesium intake, magnesium biomarkers and serum leptin concentrations were measured. Serum leptin concentrations showed a statistically significant difference between groups (p < 0.001). Mean values of magnesium intake were lower than intake recommended, and with no statistically significant difference between two groups (p > 0.05). Women with obesity had lower plasma and erythrocyte magnesium concentrations than control group did (p < 0.001). Magnesium concentrations found in the urine of women with obesity were higher than the control group was, with a statistically significant difference (p < 0.001). There was a correlation between serum leptin and magnesium biomarkers (p < 0.001). Women with obesity show an inadequate magnesium nutritional status characterized by low plasma and erythrocyte concentrations and high concentrations in urine, and they also have high serum leptin concentrations. Thus, it was possible to observe a correlation between hyperleptinemia and magnesium biomarkers, requiring further studies to determine whether the dysfunction of this hormone can influence the compartmentalization of the mineral in obese organisms.

Antiviral and immunological activity of zinc and possible role in COVID-19.

Zn deficiency compromises its biological functions, its effect on the immune system and its antiviral activity, increasing vulnerability to infectious diseases. This narrative review aims at presenting and discussing functional aspects and possible mechanisms involved in the potential role of Zn in the immune response and antiviral activity for coronavirus infectious disease-19 (COVID-19) prevention and control. The searches were conducted in PubMed and Science Direct databases, using clinical trials, experimental studies in animals and humans, case-control studies, case series, letters to the editor, and review articles published in English, without restrictions on year of publication. Search approach was based on using the terms: 'zinc', 'COVID-19', 'antiviral agents', 'immunologic factors' and 'respiratory tract infections'. Literature shows the importance of Zn as an essential mineral immunomodulator with relevant antiviral activity in the body. Thus, although there is still a scarcity of studies evaluating Zn supplementation in patients with COVID-19, the results on the topic show the necessity of controlling Zn mineral deficiency, as well as maintaining its homoeostasis in the body in order to strengthen the immune system and improve the prevention of highly complex viral infections, such as that of the COVID-19.

Calcium and phosphorus parameters and their association with serum parathormone in chronic kidney patients on hemodialysis

ABSTRACT The objective of this study was to investigate the association between calcium and phosphorus parameters with serum parathormone concentrations in patients with Chronic Kidney Disease (CKD) undergoing hemodialysis. It is descriptive quantitative cross-sectional study. The sample was composed of 50 individuals distributed in: group with up to 5 years of hemodialysis and group with more than 5 years of hemodialysis. Food consumption was assessed using 24-hour dietary recall. Descriptive analysis of quantitative variables was presented as mean and standard deviation. Data analysis was performed using the SPSS program; Student "T" test, Fisher's exact test and Pearson's chi-square test were used, with significance level p <0.05. The groups presented adequate serum calcium concentrations and high concentrations of phosphorus and parathormone. Patients with more than 5 years of hemodialysis had a statistically higher serum parathormone level (p= 0.034); there was an association between longer hemodialysis time and higher serum phosphorus concentrations (p= 0.039). There was a moderate positive correlation between serum parathormone and phosphorus in the group with up to 5 years of hemodialysis (p= 0.012). It was concluded that the progression of CKD increases serum phosphorus and parathormone concentrations, reflecting the pathophysiological events and altered metabolic demand inherent to the pathology.

RESUMEN El objetivo de este trabajo fue investigar la asociación de los parámetros de calcio y fósforo con las concentraciones séricas de parathormona en pacientes con enfermedad renal crónica (ERC) en hemodiálisis. Se trata de un estudio descriptivo, cuantitativo y transversal. La muestra estuvo constituida por 50 individuos distribuidos en: grupo con hasta 5 años en hemodiálisis y grupo con más de 5 años en hemodiálisis. El consumo de alimentos se evaluó mediante el recordatorio de 24 horas. El análisis descriptivo de las variables cuantitativas se presentó como media y desviación estándar de la media. El análisis de los datos se realizó mediante el programa SPSS; Se utilizó la prueba "T" de Student, la prueba exacta de Fisher y la prueba de chi-cuadrado de Pearson, con un nivel de significancia de p <0.05. Los grupos mostraron concentraciones adecuadas de calcio sérico y altas concentraciones de fósforo y parathormona. Los pacientes con más de 5 años de hemodiálisis tenían un nivel de parathormona sérica estadísticamente más alto (p= 0,034); hubo una asociación entre un mayor tiempo de hemodiálisis y mayores concentraciones de fósforo sérico (p= 0,039). Hubo una correlación positiva moderada entre parathormona sérica y fósforo en el grupo con hasta 5 años de hemodiálisis (p= 0.012). Se concluyó que la progresión de la ERC aumenta las concentraciones séricas de fósforo y parathormona, reflejando los eventos fisiopatológicos y alteración de la demanda metabólica inherente a la patología.

Magnesium parameters and their association with lipid metabolism markers in obese women

ABSTRACT Background: The objective of this study was to evaluate whether low magnesium concentration is related to increased cardiovascular risk in obese women. Methods: This case-control study included women, who were divided into two groups: case (BMI>35 kg/m2) and control group (18.5>BMI>24.9 kg/m2). Body weight, height, waist, neck and hip circumference were measured according to the methodology described by the Ministry of Health. The analyses of plasma, erythrocyte, and urinary magnesium concentrations were performed using the inductively coupled plasma optical emission spectrometry method. The lipid fractions were analyzed according to the enzymatic colorimetric method using a Cobas Integra automatic biochemical analyzer. Results: Mean plasma and erythrocyte magnesium concentrations were lower in the obese women compared to the control group (p<0.05). The urinary excretion of this mineral showed a significant difference between the two groups (p<0.05), and the obese women excreted a higher amount of magnesium in the urine. With regard to the cardiovascular risk parameters, obese women demonstrated higher values compared to the control group (p<0.05). The study showed a negative correlation between erythrocyte magnesium and systolic and diastolic blood pressure in the control group (p<0.05). Conclusion: These results indicate that obese women exhibit changes in nutritional status with regard to magnesium, with reduced concentrations in plasma and erythrocytes, and increased concentration in the urine. However, the results do not suggest a role of magnesium in protection against cardiovascular risk factors in the patients evaluated in this study.

RESUMEN El objetivo de este estudio fue evaluar si una concentración baja de magnesio está relacionada con un mayor riesgo cardiovascular en mujeres obesas. Métodos: Este estudio de casos y controles incluyó mujeres, que se dividieron en dos grupos: grupo de casos (IMC>35 kg/m2) y control (18,5>IMC>24,9 kg/m2). El peso corporal, la altura, la cintura, la circunferencia del cuello y la cadera se midieron según la metodología descrita por el Ministerio de Salud. Los análisis de las concentraciones de magnesio en plasma, eritrocitos y orina se realizaron utilizando el método de espectrometría de emisión óptica de plasma acoplado inductivamente. Las fracciones lipídicas se analizaron según el método colorimétrico enzimático utilizando un analizador bioquímico automático Cobas Integra. Resultados: Las concentraciones medias de magnesio en plasma y eritrocitos fueron menores en las mujeres obesas en comparación con el grupo de control (p<0.05). La excreción urinaria de este mineral mostró una diferencia significativa entre los dos grupos (p<0.05), y las mujeres obesas excretaron una mayor cantidad de magnesio en la orina. En cuanto a los parámetros de riesgo cardiovascular, las mujeres obesas mostraron valores más altos en comparación con el grupo control (p<0,05). El estudio mostró una correlación negativa entre el magnesio de los eritrocitos y la presión arterial sistólica y diastólica en el grupo de control (p<0,05). Conclusión: Estos resultados indican que las mujeres obesas presentan cambios en el estado nutricional con respecto al magnesio, con concentraciones reducidas en el plasma y eritrocitos, y concentración aumentada en la orina. Sin embargo, los resultados no sugieren un papel del magnesio en la protección contra los factores de riesgo cardiovascular en los pacientes evaluados en este estudio.

Relation Between Zinc and Thyroid Hormones in Humans: a Systematic Review.

The aim of this study was to systematically evaluate the relation between zinc and the thyroid hormones in humans. The search for articles was conducted using the Pubmed, Scopus, Cochrane Central Register of Controlled Trials (CENTRAL), and ScienceDirect databases on October 21 and 22, 2019, by two authors independently. The recommendations of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) were followed in the conduct of this review. The Cochrane Collaboration tool was used to assess the risk of bias of the trials included in this review. After the screening of the articles, eight studies that assessed the effects of zinc supplementation on thyroid hormone concentrations and ten studies that assessed the relationship between blood zinc concentrations and thyroid hormones were included in this systematic review. Although cross-sectional and case-control studies have shown a relationship between zinc deficiency and thyroid, the data from this systematic review provides inconclusive evidence with respect to the effects of zinc supplementation on thyroid hormone concentrations due to the divergence of the research found by the authors that only reports findings in patients suffering from some kind of disease, which cannot be generalized to the average human population.

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 50 years old who were divided into case group (BMI ≥ 35 kg/m2) and control group (BMI = 18.5-24.9 kg/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 ± 3.12 mg/day and 11.37 ± 4.36 mg/day for control and obeses, respectively). Obese women had reduced plasma (67.22 ± 5.96 µg/dL) and erythrocyte (37.16 ± 3.64 µg Zn/gHb) zinc concentrations when compared to the control group (plasma: 89.71 ± 13.33 µg/dL; erythrocyte: 42.68 ± 3.73 µg 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 ± 0.63 pg/dL; obeses: 2.09 ± 0.34 pg/dL), and Free T4 (control: 1.12 ± 0.31 ng/dL; obeses: 1.09 ± 0.19 ng/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-1ß, 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.

The Role of Zinc in Thyroid Hormones Metabolism.

Thyroid hormones play an important role in body homeostasis by facilitating metabolism of lipids and glucose, regulating metabolic adaptations, responding to changes in energy intake, and controlling thermogenesis. Proper metabolism and action of these hormones requires the participation of various nutrients. Among them is zinc, whose interaction with thyroid hormones is complex. It is known to regulate both the synthesis and mechanism of action of these hormones. In the present review, we aim to shed light on the regulatory effects of zinc on thyroid hormones. Scientific evidence shows that zinc plays a key role in the metabolism of thyroid hormones, specifically by regulating deiodinases enzymes activity, thyrotropin releasing hormone (TRH) and thyroid stimulating hormone (TSH) synthesis, as well as by modulating the structures of essential transcription factors involved in the synthesis of thyroid hormones. Serum concentrations of zinc also appear to influence the levels of serum T3, T4 and TSH. In addition, studies have shown that Zinc transporters (ZnTs) are present in the hypothalamus, pituitary and thyroid, but their functions remain unknown. Therefore, it is important to further investigate the roles of zinc in regulation of thyroid hormones metabolism, and their importance in the treatment of several diseases associated with thyroid gland dysfunction.

No Difference in Magnesium Intake between Obese Women and Healthy Controls.

Magnesium is a predominantly intracellular ion and plays an important role in energy metabolism and in the maintenance of energy homeostasis. This study aimed to estimate the dietary intake of magnesium and its association with adiposity parameters in obese women. This cross-sectional study included 125 women, aged between 20 and 50 years, who were divided into two groups: obese group (n = 62) and control group (n = 63). The control group was age-matched. Adiposity parameters determined were weight, body mass index and waist circumference as well as the intake of calories, macronutrients, and magnesium were calculated. The cut-off for obesity was body mass index between 30.0 and 39.9 kg/m2 and for control group was between 18.5 and 24.9 kg/m2 Food intake was calculated using 3-day food records, and energy consumption as well as the intake of macronutrients and magnesium was calculated using the NutWin software version 1.5. The reference values used were the Acceptable Macronutrient Distribution Range for macronutrients and the Estimated Average Requirement (EAR) for magnesium. The average levels of magnesium found in the diet were lower than those recommended (169.1 ± 64.5 mg Mg/day and 158.5 ± 42.9 mg Mg/day, for obese women and control group, respectively) and the differences between the groups were not statistically different (p > 0.05). The correlation analysis indicated that the association between the dietary intake of magnesium and adiposity was not significant. The results of this study indicate that dietary magnesium does not influence the adiposity parameters in obese women.

Association Between Cortisol, Insulin Resistance and Zinc in Obesity: a Mini-Review.

Adipose tissue is considered an endocrine organ and its excess compromises the immune response and the metabolism of hormones and nutrients. Furthermore, visceral fat accumulation contributes to increased cortisol synthesis, which in turn induces metallothionein and Zip14 expression, which are proteins that contribute to reducing plasma zinc levels. Zinc plays a critical role in the secretion and signaling of insulin. Changes in the biochemical parameters of zinc, as observed in individuals who are obese, contribute to the manifestation of related disorders such as insulin resistance. Thus, the purpose of this review is to provide an update on the current information on the relationship between cortisol, zinc, and insulin resistance in obesity. The data in the literature provide evidence that cortisol affects zinc metabolism, and indicate possible repercussions on insulin signaling that might contribute to the development of resistance to the actions of insulin in obesity.

Zinc and Insulin Resistance: Biochemical and Molecular Aspects.

Studies have shown the participation of minerals in mechanisms involved in the pathogenesis of insulin resistance. Zinc, in particular, seems to play an important role in the secretion and action of this hormone. Therefore, the aim of this review is to understand the role of zinc in increasing insulin sensitivity. We conducted a search of articles published in the PubMed and ScienceDirect database selected from March 2016 to February 2018, using the keywords "zinc," "insulin," "insulin resistance," "insulin sensitivity," and "supplementation." Following the eligibility criteria were selected 53 articles. The scientific evidences presented in this review show the importance of zinc and their carrier proteins in the synthesis and secretion of insulin, as well as in the signaling pathway of action of this hormone. Zinc deficiency is associated with glucose intolerance and insulin resistance; however, the effectiveness of the intervention with the zinc supplementation is still inconclusive.

Role of vitamin D in insulin resistance in obese individuals

BACKGROUND: Vitamin D is a fat-soluble compound responsible for promoting intestinal absorption of calcium, and this, in turn, acts as a signal transmitter or activator as protein in secretory processes and release of hormones. VitaminD receptors are distributed in various tissues of the body and involved in biochemical reactions in the pathogenesis of several diseases, such as obesity. OBJECTIVE: The aim of this article is to provide updated information on the role of vitamin D in insulin resistance inobese individuals. METHODS: It was conducted a search of articles published in PubMED, SciELO, and LILACS database, without limit forthe year of publication, using the keywords"vitamin D","insulin resistance",and "obesity". RESULTS: Excess adipose tissue seems to impair insulin signaling by inhibiting the phosphorylation of its receptor, resultingin insulin resistance. Studies have evidenced role of vitamin D in mechanisms involved in the pathogenesis of insulin resistance in obesity by acting in improving glycemic control both by increasing hepatic and peripheral glucoseup take and by promoting the secretion of this hormone. CONCLUSIONS: Vitamin D exerts a protective effect in the treatment and prevention of insulin resistance in patients with obesity and protects the body against oxidative stress and chronic inflammation, contributing to glycemic control. Unfortunately, current data related to the effects of vitamin D supplementation on insulin resistance are still inconclusive