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.

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.

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.

Expression of metalloproteinases 2 and 9 and plasma zinc concentrations in women with fibroadenoma.

OBJECTIVE: This study aims to investigate the association between the immunohistochemical expression of matrix metalloproteinase-2 and matrix metalloproteinase-9 and plasma zinc in women with fibroadenoma. METHODS: This cross-sectional study included 37 premenopausal women with fibroadenoma. Waist circumference and body mass index of the participants were measured. Plasma zinc concentrations were determined using atomic flame absorption spectrophotometry. Fragments of breast tissue were fixed and incubated with primary mouse monoclonal antibodies (monoclonal antibodies matrix metalloproteinase -2 -507 and monoclonal antibodies matrix metalloproteinase -9-439). Semi-quantitative analysis of matrix metalloproteinase-2 and matrix metalloproteinase-9 immunoreactivity was performed. Spearman's test and Friedman's test were used for statistical analyses. The p<0.05 were considered statistically significant. RESULTS: The average age of the participants was 32.81±9.51 years. The body mass index and waist circumference values were within the normal range. The mean plasma zinc concentration was 42.73±13.84 µg/dL, with 94.6% inadequacy. A statistically significant difference was found between the positive expression of matrix metalloproteinase-2 and matrix metalloproteinase-9 (p=0.0184). There was no significant correlation between the matrix metalloproteinase expression and the plasma zinc levels. CONCLUSIONS: Women with fibroadenoma had hypozincemia and positive expression of metalloproteinases.

Association between calcium/magnesium ratio and insulin resistance in women with obesity and normal-weight women

ABSTRACT The aim of this study was to evaluate the association between the calcium/magnesium (Ca/Mg) ratio and insulin resistance in women with obesity and normal-weight women. This was a cross-sectional study with 128 women (62 women with obesity and 66 normal-weight women). We measured dietary minerals intake and analyzed magnesium and calcium biomarkers. Ca/Mg ratio in diet, plasma and urine were calculated. We have evaluated glycemic parameters. Women with obesity had low dietary magnesium, reduced plasma and erythrocyte magnesium concentrations, and elevated urinary magnesium excretion. Plasma calcium concentration was lower and urinary calcium excretion was higher in patients with obesity than in the normal-weight group. Dietary magnesium and calcium intake per kilogram of body weight per day was lower in obese women than in the control group. Ca/Mg ratio in plasma and urine were elevated in women with obesity. We found a significant correlation among magnesium biomarkers and calcium parameters. Ca/Mg ratio seems to be associated with insulin resistance in obese women.

RESUMEN El objetivo de este estudio fue evaluar la asociación entre la relación Ca/Mg y la resistencia a la insulina en mujeres con obesidad y en mujeres con peso normal. El diseño del estudio fue transversal y participaron 128 mujeres (62 mujeres con obesidad y 66 mujeres con peso normal). Se analizó la ingesta de minerales en la dieta y se realizaron análisis de biomarcadores de magnesio y calcio. Se calculó la relación Ca/Mg en dieta, plasma y orina y se evaluaron los parámetros glicémicos. Las mujeres con obesidad tenían niveles bajos de magnesio en la dieta, concentraciones reducidas de magnesio en plasma y eritrocitos, y excreción urinaria de magnesio elevada. La concentración plasmática de calcio fue menor en pacientes con obesidad, y la excreción urinaria de calcio fue mayor que en el grupo de mujeres con peso normal. La ingesta dietética de magnesio y calcio por kilogramo de peso corporal por día fue menor en las mujeres con obesidad, que en el grupo control. La relación Ca/Mg en plasma y orina estaba elevada en mujeres con obesidad. Se encontró una correlación significativa entre los biomarcadores de magnesio y los parámetros de calcio. La relación Ca / Mg parece estar asociada con la resistencia a la insulina en mujeres con obesidad.

Expression of metalloproteinases 2 and 9 and plasma zinc concentrations in women with fibroadenoma

SUMMARY OBJECTIVE: This study aims to investigate the association between the immunohistochemical expression of matrix metalloproteinase-2 and matrix metalloproteinase-9 and plasma zinc in women with fibroadenoma. METHODS: This cross-sectional study included 37 premenopausal women with fibroadenoma. Waist circumference and body mass index of the participants were measured. Plasma zinc concentrations were determined using atomic flame absorption spectrophotometry. Fragments of breast tissue were fixed and incubated with primary mouse monoclonal antibodies (monoclonal antibodies matrix metalloproteinase -2 -507 and monoclonal antibodies matrix metalloproteinase -9-439). Semi-quantitative analysis of matrix metalloproteinase-2 and matrix metalloproteinase-9 immunoreactivity was performed. Spearman's test and Friedman's test were used for statistical analyses. The p<0.05 were considered statistically significant. RESULTS: The average age of the participants was 32.81±9.51 years. The body mass index and waist circumference values were within the normal range. The mean plasma zinc concentration was 42.73±13.84 µg/dL, with 94.6% inadequacy. A statistically significant difference was found between the positive expression of matrix metalloproteinase-2 and matrix metalloproteinase-9 (p=0.0184). There was no significant correlation between the matrix metalloproteinase expression and the plasma zinc levels. CONCLUSIONS: Women with fibroadenoma had hypozincemia and positive expression of metalloproteinases.

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.

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

Associations between taste sensitivity, preference for sweet and salty flavours, and nutritional status of adolescents from public schools / Associação entre sensibilidade gustativa, preferência aos sabores doce e salgado e estado nutricional de adolescentes

ABSTRACT Objective This study aimed to investigate the associations between taste sensitivity, preference for sweet and salty flavours, and nutritional status of adolescents in public schools. Methods We used a cross-sectional study involving 1,036 adolescents of both sexes, aged 10-19 years. Preference for sweet or salty flavours and preference for foods high in sugar or sodium were evaluated. Measurements of body mass index and taste flavour intensity recognition were conducted. Results Most participants were unable to identify the flavours and/or intensities, and only 18.0% of participants were able to correctly identify both the flavour and intensity of the samples. Most participants (82.1%) preferring sweet foods had low sensitivity to this taste, just as a large proportion of individuals preferring saltiness (82.3%) were less sensitive to salt (p<0.001). Preference for saltiness was associated with pre-obesity. Conclusion We found an association between a preference for sweet or salty flavours and nutritional status, highlighting the importance of poor food choices in the development of obesity and other chronic diseases.

RESUMO Objetivo Este estudo teve como objetivo investigar a associação entre a sensibilidade gustativa, a preferência pelos sabores doce e salgado e o estado nutricional de adolescentes em escolas públicas. Métodos Estudo de natureza transversal, envolvendo 1.036 adolescentes de ambos os sexos, com idade entre 10 e 19 anos. A preferência pelos sabores doce e salgado e por alimentos ricos em açúcar ou sódio foi avaliada. Medidas do índice de massa corporal e testes de reconhecimento de gosto-intensidade foram conduzidos. Resultados A maioria dos participantes foi incapaz de identificar os sabores e/ou intensidades e somente 18,0% dos participantes foram capazes de identificar corretamente o sabor e intensidade das amostras. A maioria dos participantes (82,1%) preferiram alimentos doces e tiveram baixa sensibilidade a esse gosto, bem como uma grande proporção de indivíduos que preferem salgado (82,3%) eram menos sensíveis ao sal (p<0,001). A preferência pelo gosto salgado foi associada com excesso de peso. Conclusão Foi encontrada uma associação entre a preferência pelos sabores doce e salgado e o estado nutricional, destacando a importância de escolhas alimentares pobres no desenvolvimento de obesidade e outras doenças crônicas.

Effect of magnesium supplementation on insulin resistance in humans: A systematic review.

OBJECTIVES: Recent studies have demonstrated that minerals play a role in glucose metabolism disorders in humans. Magnesium, in particular, is an extensively studied mineral that has been shown to function in the management of hyperglycemia, hyperinsulinemia, and insulin resistance (IR) action. The aim of this study was to investigate the effect of magnesium supplementation on IR in humans via systematic review of the available clinical trials. METHODS: This review was conducted in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) recommendations. A survey was conducted to select clinical trials related to the effects of this mineral in insulin sensitivity using the following databases: PubMed, SciVerse Scopus, ScienceDirect, and SciVerse Cochrane. RESULTS: After the selection process, 12 articles were identified as eligible, representing different clinical conditions and being free of restriction with regard to sex, age, ethnicity, and differential dosing/shape of magnesium. The results of eight clinical trials showed that supplementation with magnesium influences serum fasting glucose concentrations, and five trials determined an effect on fasting insulin levels. The results of seven studies demonstrated that mineral supplementation reduced homeostasis model assessment for IR values. CONCLUSIONS: The data of this systematic review provide evidence as to the benefits of magnesium supplementation in reducing IR in patients with hypomagnesemia presenting IR. However, new intervention studies are needed to elucidate the role of the nutrient in protection against this metabolic disorder, as well as the standardization of the type, dose, and time of magnesium supplementation.