Magnesium, selenium and zinc deficiency compromises antioxidant defense in women with obesity.

Studies have shown that deficiencies in magnesium, selenium, and zinc in individuals with obesity compromise the endogenous antioxidant defense system. This study aimed to evaluate the impact of mineral deficiency on enzymatic antioxidant defense in women with obesity. The study involved 63 women with obesity (BMI ≥ 35 kg/m2) and 77 eutrophic women (BMI between 18.5 and 24.9 kg/m2). Variables such as fasting glucose, glycated hemoglobin, fasting insulin, and serum lipids were analyzed. Insulin resistance was measured using the homeostasis assessment model (HOMA-IR) and beta cell function using the homeostasis assessment model (HOMA-ß). Dietary intake of energy, macronutrients (including magnesium, zinc, and selenium), and plasma, erythrocyte, and urinary concentrations of these minerals were measured and analyzed. Serum cortisol, plasma leptin, plasma thiobarbituric acid reactive substances, and the activity of erythrocyte superoxide dismutase (SOD), erythrocyte glutathione peroxidase (GPX), and erythrocyte catalase were also analyzed. Women with obesity had reduced plasma and erythrocyte concentrations and greater urinary excretion of all minerals compared to normal weight women (p < 0.05). There was a positive association between erythrocyte concentrations of zinc and selenium and the activity of the GPX and SOD enzymes in erythrocytes in women with obesity (p < 0.05), in addition to a positive association between serum insulin and the enzyme GPX, which is dependent on dietary selenium (p < 0.05). Individuals with obesity are deficient in magnesium, selenium, and zinc, which appears to impair the antioxidant defense system and contribute to important metabolic disorders such as oxidative stress in these patients.

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.

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.

Role of Zinc in Zinc-α2-Glycoprotein Metabolism in Obesity: a Review of Literature.

Excessive adipose tissue promotes the manifestation of endocrine disorders such as reduction of the secretion of zinc-α2-glycoprotein (ZAG), an adipokine with anti-inflammatory and lipid-mobilizing activity. The molecular structure of this adipokine includes binding sites for zinc, a trace element with important antioxidant and immunological proprieties that also participates in energy metabolism and stimulates the function of ZAG. The objective of this review is to highlight current data on the metabolism of ZAG in obesity and the role of zinc in this process. The identified studies show that subjects with obesity have low serum concentrations of zinc and ZAG, as well as low expression of the genes encoding this protein. Thus, zinc appears to be an important regulator of the homeostasis of ZAG in the body; however, alterations in the metabolism of zinc in obesity appear to compromise the functions of ZAG. Therefore, further studies are needed to clarify the relationship between zinc and ZAG metabolism and its repercussions in obesity.

[Do children and adolescents who consume ultra-processed foods have a worse lipid profile? A systematic review]. / Crianças e adolescentes que consomem alimentos ultraprocessados possuem pior perfil lipídico? Uma revisão sistemática.

The increase in the input of ultra-processed ingredients in the food of children and adolescents is related to the development of noncommunicable diseases such as dyslipidemia. The scope of this study was to conduct a systematic review of the literature on the relationship of consumption of ultra-processed foods in the lipid profile of children and adolescents. A search in the PubMed, Scopus, Cochrane and LILACS databases was carried out to locate cross-sectional and longitudinal studies, with or without intervention, in apparently healthy children and/or adolescents, who had the intake of ultra-processed food as an exposure variable and the lipid profile as an outcome. After screening, 14 studies were included, of which nine demonstrated that ultra-processed food consumption was related to increased LDL-c, total cholesterol, triglycerides and a reduction in HDL-c. Three studies found no relationship and two demonstrated that the increased intake of ready-to-eat cereals was related to the decrease in total cholesterol and LDL-c. There was a high consumption of ultra-processed foods and positive relation with blood lipids among children and adolescents, which calls attention to interventions, such as nutritional education, with a view to reducing the intake of these foods.

O aumento da participação de alimentos ultraprocessados na alimentação de crianças e adolescentes está relacionado ao desenvolvimento de agravos não transmissíveis, como dislipidemia. Objetivou-se realizar uma revisão sistemática da literatura sobre a relação do consumo de alimentos ultraprocessados e o perfil lipídico de crianças e adolescentes. Realizou-se uma busca nas bases de dados PubMed, Scopus, Cochrane e LILACS por estudos com desenhos transversais e longitudinais, com ou sem intervenção; em crianças e/ou adolescentes aparentemente saudáveis, que tivessem a ingestão de alimento ultraprocessado como variável de exposição e o perfil lipídico como desfecho. Após triagem, 14 estudos foram incluídos, destes, nove demonstraram que o consumo de ultraprocessados estava relacionado com o aumento do LDL-c, colesterol total, triglicerídeos e diminuição do HDL-c. Três estudos não encontraram nenhuma relação e dois demonstraram que a maior ingestão de cereais prontos estava relacionada com a diminuição de colesterol total e LDL-c. Observou-se elevado consumo de alimentos ultraprocessados e relação positiva com lipídios sanguíneos em crianças e adolescentes o que chama atenção para a realização de intervenções, como educação nutricional, com vistas a reduzir a ingestão desses alimentos.

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 Oxidative Stress: Current Mechanisms.

Oxidative stress is a metabolic dysfunction that favors the oxidation of biomolecules, contributing to the oxidative damage of cells and tissues. This consequently contributes to the development of several chronic diseases. In particular, zinc is one of the most relevant minerals to human health, because of its antioxidant properties. This review aims to provide updated information about the mechanisms involved in the protective role of zinc against oxidative stress. Zinc acts as a co-factor for important enzymes involved in the proper functioning of the antioxidant defense system. In addition, zinc protects cells against oxidative damage, acts in the stabilization of membranes and inhibits the enzyme nicotinamide adenine dinucleotide phosphate oxidase (NADPH-Oxidase). Zinc also induces the synthesis of metallothioneins, which are proteins effective in reducing hydroxyl radicals and sequestering reactive oxygen species (ROS) produced in stressful situations, such as in type 2 diabetes, obesity and cancer. Literature provides strong evidence for the role of zinc in the protection against oxidative stress in several diseases.

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.

Association between magnesium, selenium and zinc consumption and lipid profile of brazilian adolescents / Asociación entre el consumo de magnesio, selenio y zinc y el perfil lipídico de los adolescentes brasileños

ABSTRACT The study aims to evaluate the association between inadequate consumption of antioxidant minerals and plasma lipoprotein concentrations in adolescents. We conducted a cross-sectional study that evaluated sociodemographic and anthropometric data, information on intake of magnesium, selenium and zinc and lipid profile. Student's t-test was used to compare means between the groups and logistic regression to verify the strength of the association between the independent variables and lipid profile. Inadequate zinc consumption was associated with a higher chance of low HDL-c levels and lower chance of hypertriglyceridemia and high LDL-c levels. Inadequate selenium intake was associated with a lower chance of high total cholesterol and of high triglyceride concentrations and a higher chance of low HDL-c levels. Inadequate magnesium consumption was associated with a higher chance of high cholesterol and triglyceride levels, a lower chance of high LDL-c levels and with a higher chance of low HDL-c. We observed an association between inadequate consumption of magnesium, zinc and selenium and changes in the lipid profile of adolescents.

RESUMEN El estudio tiene como objetivo evaluar la asociación entre el consumo inadecuado de minerales antioxidantes y las concentraciones plasmáticas de lipoproteínas en adolescentes. Estudio transversal que evaluó datos sociodemográficos y antropométricos, información sobre ingesta de magnesiom selenio y zinc y perfil lipídico. Se utilizó la prueba t de Student para comparar medias entre los grupos y regresión logística para verificar la fuerza de la asociación entre las variables independientes y el perfil lipídico. El consumo inadecuado de zinc se asoció con una mayor probabilidad de niveles bajos de HDL-c y una menor probabilidad de hipertrigliceridemia y niveles altos de LDL-c. La ingesta inadecuada de selenio se asoció con una menor probabilidad de colesterol total alto y de altas concentraciones de triglicéridos y una mayor probabilidad de niveles bajos de HDL-c. El consumo inadecuado de magnesio se asoció con una mayor probabilidad de niveles altos de colesterol y triglicéridos, una menor probabilidad de niveles altos de LDL-c y una mayor probabilidad de niveles bajos de HDL-c. El estudio muestra una asociación entre el consumo inadecuado de magnesio, zinc y selenio y los cambios en el perfil lipídico de los adolescentes.

Crianças e adolescentes que consomem alimentos ultraprocessados possuem pior perfil lipídico? Uma revisão sistemática / Do children and adolescents who consume ultra-processed foods have a worse lipid profile? A systematic review

Resumo O aumento da participação de alimentos ultraprocessados na alimentação de crianças e adolescentes está relacionado ao desenvolvimento de agravos não transmissíveis, como dislipidemia. Objetivou-se realizar uma revisão sistemática da literatura sobre a relação do consumo de alimentos ultraprocessados e o perfil lipídico de crianças e adolescentes. Realizou-se uma busca nas bases de dados PubMed, Scopus, Cochrane e LILACS por estudos com desenhos transversais e longitudinais, com ou sem intervenção; em crianças e/ou adolescentes aparentemente saudáveis, que tivessem a ingestão de alimento ultraprocessado como variável de exposição e o perfil lipídico como desfecho. Após triagem, 14 estudos foram incluídos, destes, nove demonstraram que o consumo de ultraprocessados estava relacionado com o aumento do LDL-c, colesterol total, triglicerídeos e diminuição do HDL-c. Três estudos não encontraram nenhuma relação e dois demonstraram que a maior ingestão de cereais prontos estava relacionada com a diminuição de colesterol total e LDL-c. Observou-se elevado consumo de alimentos ultraprocessados e relação positiva com lipídios sanguíneos em crianças e adolescentes o que chama atenção para a realização de intervenções, como educação nutricional, com vistas a reduzir a ingestão desses alimentos.

Abstract The increase in the input of ultra-processed ingredients in the food of children and adolescents is related to the development of noncommunicable diseases such as dyslipidemia. The scope of this study was to conduct a systematic review of the literature on the relationship of consumption of ultra-processed foods in the lipid profile of children and adolescents. A search in the PubMed, Scopus, Cochrane and LILACS databases was carried out to locate cross-sectional and longitudinal studies, with or without intervention, in apparently healthy children and/or adolescents, who had the intake of ultra-processed food as an exposure variable and the lipid profile as an outcome. After screening, 14 studies were included, of which nine demonstrated that ultra-processed food consumption was related to increased LDL-c, total cholesterol, triglycerides and a reduction in HDL-c. Three studies found no relationship and two demonstrated that the increased intake of ready-to-eat cereals was related to the decrease in total cholesterol and LDL-c. There was a high consumption of ultra-processed foods and positive relation with blood lipids among children and adolescents, which calls attention to interventions, such as nutritional education, with a view to reducing the intake of these foods.

The role of selenium in insulin resistance

ABSTRACT In recent years, there has been growing interest in clarifying the pathogenesis of some chronic diseases, such as obesity and type 2 diabetes mellitus. Metabolic alterations in these diseases are characterized by chronic hyperglycemia and insulin resistance. Studies have demonstrated the participation of minerals in the pathogenesis of insulin resistance, more specifically their involvement in the synthesis and regulation of insulin. Selenium is an anti-inflammatory and antioxidant micronutrient that is essential for the activity of selenoproteins. Two selenoproteins (glutathione peroxidase and selenoprotein P) are known to be involved in the insulin signaling pathway. The aim of this review is to provide an update on the role of selenium in insulin resistance mechanisms. Evidence shows that adequate concentrations of selenium play a key role in the secretion and action of insulin, but an excess of selenium in the body is associated with the pathogenesis of insulin resistance and the development of diabetes mellitus.