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.

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.

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.

Abstract INTRODUCTION: Malnutrition and kala-azar (or visceral leishmaniasis) are significant public health problems in different parts of the world. Immunity and susceptibility to infectious and parasitic diseases are directly linked to the host’s nutritional state, but little is known about the interaction between nutrition and kala-azar. This study aimed to evaluate nutritional status with kala-azar and correlate these findings with the clinical and laboratory manifestations of the disease, and zinc and retinol levels. METHODS: This was a cross-sectional study of 139 patients with kala-azar. Nutritional status classification was performed according to international recommendations. Parametric or nonparametric tests were applied whenever indicated in a two-sided test with a 5% significance level. RESULTS: Weight loss and malnutrition were more frequent in adults. Body mass index-for-age, fat area of the arm, and upper arm muscle area were significantly associated with probability of death. The presence of human immunodeficiency virus, hepatomegaly, and splenomegaly was correlated with nutritional assessment. Blood leukocyte and lymphocyte, serum creatine, and vitamin A levels were significantly higher in adult men. Vitamin A levels were highly associated with the level of hemoglobin and C-reactive protein (CRP) in multivariate analysis. All patients had reduced plasma zinc levels, but this finding had no association with the outcome variables. CONCLUSIONS: Malnutrition was correlated with severe disease and was more prevalent in older people with kala-azar. Vitamin A deficiency was associated with hemoglobin and CRP. Zinc levels were reduced in patients with kala-azar.

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.

Introduction: The relationship between diet and health has aroused scientific interest, especially the consumption of antioxidant nutrients naturally present in foods, because of its action against the deleterious effects of free radicals in the body. Objective: This study aimed to estimate the intake of antioxidant nutrients and its relationship with lipid profile and oxidative stress in student users of a university restaurant in comparison with non-users. Methods: This cross-sectional study involved 145 university students divided into two groups: users of the university restaurant (group 1, n = 73) and non-users (group 2, n = 72). We measured body mass index and waist circumference, and estimated the intake of antioxidant micronutrients. Serum concentrations of total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, and triglyceride levels, and plasma concentrations of malondialdehyde were determined. Results and conclusion: Intake of copper, zinc, selenium, and vitamin C were within the recommendations in both groups, and vitamins A and E were below the reference values. There was a correlation between the intake of vitamin C and triglycerides. Group 1 members had better dietary patterns in relation to antioxidant micronutrients, reflecting less atherogenic lipid profile and lower exposure to oxidative stress compared to group 2.

Introducción: la relación entre la dieta y la salud ha despertado interés científico, especialmente en lo referente al consumo de nutrientes antioxidantes presentes de forma natural en los alimentos, debido a su acción contra los efectos nocivos de los radicales libres en el cuerpo. Objetivo: el objetivo de este estudio fue estimar la ingesta de nutrientes antioxidantes y su relación con el perfil lipídico y el estrés oxidativo en estudiantes usuarios de un restaurante universitario, en comparación con los no usuarios. Métodos: este es un estudio transversal que incluye 145 estudiantes universitarios, divididos en dos grupos: los usuarios del restaurante universitario (grupo 1, n = 73) y no usuarios (grupo 2, n = 72). Fueron medidos el índice de masa corporal y la circunferencia de la cintura, y se estimó la ingesta de micronutrientes antioxidantes. Se determinaron las concentraciones séricas de colesterol total, colesterol unido a lipoproteínas de alta densidad, colesterol unido a lipoproteínas de baja densidad, los niveles de triglicéridos y las concentraciones plasmáticas de malondialdehído. Resultados y conclusiones: la ingesta de cobre, zinc, selenio y la vitamina C se encontraba dentro de las recomendaciones de los dos grupos, y la de vitaminas A y E estaba por debajo de los valores de referencia. Hubo una correlación entre el consumo de vitamina C y los triglicéridos. Miembros del grupo 1 mostraron mejores patrones dietéticos en relación con micronutrientes antioxidantes, lo que refleja menos perfil lipídico aterogénico y una menor exposición al estrés oxidativo en comparación con el grupo 2.

Resumo Introdução: O acúmulo de gordura visceral na obesidade está associado à produção excessiva de adipocinas pró-inflamatórias, o que contribui para o estado de inflamação crônica de baixo grau. A literatura também tem mostrado que a deficiência de minerais, em particular do magnésio, possui papel importante na patogênese desse distúrbio metabólico com repercussões clínicas relevantes. Objetivo: Trazer informações atualizadas sobre a participação da hipomagnesemia na inflamação crônica de baixo grau em indivíduos obesos. Método: Bases de dados Pubmed, SciELO, Lilacs e ScienceDirect, utilizando as palavras-chave: "obesity", "magnesium" e "low grade inflammation". Resultados: As evidências científicas sugerem que a deficiência de magnésio favorece a manifestação da inflamação crônica de baixo grau em indivíduos obesos. Conclusão: É evidente a participação do magnésio, por meio de reações bioquímicas e metabólicas, na proteção contra esse distúrbio metabólico presente na obesidade.

Summary Introduction: The accumulation of visceral fat in obesity is associated with excessive production of proinflammatory adipokines, which contributes to low-grade chronic inflammation state. Moreover, the literature has shown that mineral deficiency, in particular of magnesium, has important role in the pathogenesis of this metabolic disorder with relevant clinical repercussions. Objective: To bring updated information about the participation of hypomagnesemia in the manifestation of low-grade chronic inflammation in obese individuals. Method: Articles published in PubMed, SciELO, LILACS and ScienceDirect, using the following keywords: "obesity," "magnesium" and "low grade inflammation." Results: Scientific evidence suggests that magnesium deficiency favors the manifestation of low-grade chronic inflammation in obese subjects. Conclusion: From literature data, it is evident the participation of magnesium through biochemical and metabolic reactions in protecting against this metabolic disorder present in obesity.

Resumo O zinco é componente catalítico de proteínas que regulam respostas a danos no DNA, enzimas de sinalização intracelular e metaloproteinases de matriz, proteínas importantes na carcinogênese. O objetivo desta revisão é trazer informações atualizadas sobre a participação do zinco e das metaloproteinases de matriz dos tipos 2 e 9 em mecanismos envolvidos na patogênese do câncer de mama. Realizou-se um levantamento bibliográfico, mediante consulta às bases de dados PubMed, Scielo e Lilacs. O zinco e os resíduos de cisteína são elementos estruturais compartilhados por todos os membros da família das metaloproteinases de matriz, as quais parecem estar envolvidas na propagação de vários tipos de neoplasias, incluindo o câncer de mama. Além disso, é provável que o zinco transportado seja utilizado para metalação do domínio catalítico das metaloproteinases recentemente sintetizadas antes de serem segregadas. Nesse sentido, o aumento das concentrações de zinco em compartimentos celulares e a redução desse oligoelemento no sangue de pacientes com câncer de mama parecem alterar a atividade das metaloproteinases 2 e 9, contribuindo para a ocorrência de tumor maligno. Assim, faz-se necessária a realização de novos estudos na perspectiva de esclarecer o papel do zinco e das metaloproteinases 2 e 9 na patogênese do câncer de mama.

Summary Zinc is the catalytic component of proteins that regulate responses to DNA damage, intracellular signaling enzymes, and matrix metalloproteinases, which are important proteins in carcinogenesis. The objective of this review is to bring current information on the participation of zinc and matrix metalloproteinases types 2 and 9 in mechanisms involved in the pathogenesis of breast cancer. We conducted a literature review, in consultation with the PubMed, Lilacs, and Scielo databases. The zinc and cysteine residues are structural elements shared by all members of the family of matrix metalloproteinases, and these proteins appear to be involved in the propagation of various types of neoplasms, including breast cancer. Moreover, transported zinc is likely to be used for the metalation of the catalytic domain of the newly synthesized metalloproteinases before the latter are secreted. Accordingly, increase in zinc concentrations in cellular compartments and the reduction of this trace element in the blood of patients with breast cancer appear to alter the activity of metalloproteinases 2 and 9, contributing to the occurrence of malignancy. Thus, it is necessary to carry out further studies with a view to clarify the role of zinc and metalloproteinases 2 and 9 in the pathogenesis of breast cancer.

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

Introduccion: diversos estudios muestran alteraciones en el metabolismo del zinc en mujeres con cancer de mama. Este mineral posee accion antioxidante, y los disturbios en sus parametros bioquimicos estan relacionados con peor pronostico de la enfermedad y agravamiento del proceso carcinogenico. Objetivos: este estudio evaluo la actividad de la enzima superoxido dismutasa y los parametros bioquimicos relativos al zinc e investigo la existencia de correlacion entre esas variables y el marcador del estres oxidativo en estas pacientes. Metodos: este fue un estudio caso-control con 66 mujeres, con edad ente 20 y 50 anos, distribuidas en: grupo caso (mujeres con cancer de mama, n = 34) y grupo control (mujeres saludables, n = 32). La ingestion del zinc fue realizada por medio del registro alimentario de tres dias, utilizando el programa Nutwin version 1.5. Las concentraciones de zinc plasmatico y eritrocitario fueron determinadas segun el metodo de espectrofotometria de absorcion atomica de llama (λ = 213,9). La actividad de la superoxido dismutasa fue evaluada por el metodo colorimetrico de Griess y fueron analizadas sustancias reactivas al acido tiobarbiturico (TBARS). Resultados y discusion: los valores medios de la ingestion de zinc, superoxido dismutasa y TARBS eran superiores a los recomendados para las participantes del estudio, con una diferencia estadistica para la enzima superoxido dismutasa (p>0,05). La media de las concentraciones plasmatica y eritrocitaria de zinc fueron reducidos en ambos grupos (p>0.05). Conclusiones: por lo tanto, se puede suponer que la ingesta de zinc en mujeres con cancer de mama no influye en las concentraciones plasmaticas y eritrocitarias de ese mineral. La elevada actividad de la superoxido dismutasa en las mujeres con cancer de mama puede ser debida a un mecanismo de regulación compensatorio mediante el estrés oxidativo presente en esa enfermedad.

O tecido adiposo branco (WAT) é considerado um órgão endócrino, que, em excesso, é capaz de controlar o metabolismo, pela ação de moléculas biologicamente ativas. A produção desregulada destas substâncias pela disfunção do tecido adiposo pode contribuir para as complicações presentes na obesidade. As pesquisas atuais têm esclarecido fatores e mecanismos envolvidos na atuação de substâncias pró e anti-inflamatórias na modulação da inflamação e da resistência à insulina. Em indivíduos obesos, as moléculas pró-inflamatórias produzidas pelo tecido adiposo têm sido implicadas como fator contribuinte para o desenvolvimento da resistência à insulina e aumento do risco de doença cardiovascular. Por outro lado, as moléculas com ação anti-inflamatória, que atuam na melhora da sensibilidade à insulina, têm sua produção reduzida. O desequilíbrio entre essas substâncias contribui de forma significativa para as desordens metabólicas presente em indivíduos obesos. Assim, esta revisão visa a trazer informações atualizadas sobre a atuação de moléculas secretadas pelo tecido adiposo.

White adipose tissue (WAT) is considered an endocrine organ. When present in excess, WAT can influence metabolism via biologically active molecules. Following unregulated production of such molecules, adipose tissue dysfunction results, contributing to complications associated with obesity. Previous studies have implicated pro- and anti-inflammatory substances in the regulation of inflammatory response and in the development of insulin resistance. In obese individuals, pro-inflammatory molecules produced by adipose tissue contribute to the development of insulin resistance and increased risk of cardiovascular disease. On the other hand, the molecules with anti-inflammatory action, that have been associated with the improvement of insulin sensitivity, have your decreased production. Imbalance of these substances contributes significantly to metabolic disorders found in obese individuals. The current review aims to provide updated information regarding the activity of biomolecules produced by WAT.

OBJETIVO: Na obesidade, o excesso de tecido adiposo aumenta a síntese de citocinas inflamatórias que parecem alterar o metabolismo de minerais, como o zinco. Entretanto, os mecanismos envolvidos neste processo ainda não estão totalmente esclarecidos. O estudo investigou se as concentrações de interleucina-6 (IL-6) e fator de necrose tumoral-α (TNF-α) no plasma podem influenciar os parâmetros bioquímicos do zinco. MÉTODOS: Setenta e três mulheres, com idade entre 20 e 50 anos, foram distribuídas em dois grupos: grupo caso, composto de obesas (n = 37) e grupo controle, composto de não obesas (n = 39). Análises de zinco plasmático e eritrocitário e as citocinas inflamatórias plasmáticas foram realizadas pelo método da espectrofotometria de absorção atômica e pelo ELISA, respectivamente. RESULTADOS: O zinco plasmático e as concentrações de IL-6 no plasma não mostraram diferenças significativas entre as mulheres obesas e grupo controle (p > 0,05). O valor do zinco eritrocitário foi 36,4±15,0µg/gHb nas mulheres obesas e 45,4±14,3µg/gHb (p = 0,025) no grupo controle. As concentrações de TNF-α no plasma foram 42,0±11,9 pg/mL e 19,0±1,0 pg/mL nasmulheres obesas e controles, respectivamente (p < 0,001). O zinco plasmático apresentou uma correlação negativa significativa com os valores de TNF-α (r =-0,44, p = 0,015). CONCLUSÃO: Asmulheres obesas apresentaram menores concentrações de zinco eritrocitário em relação ao grupo controle. O estudo mostra uma provável influência do processo inflamatório no metabolismo do zinco em pacientes obesos.

OBJECTIVE: In obesity, the excessive adipose tissue increases the synthesis of inflammatory cytokines, which appear to alter the metabolism of minerals, such as zinc. However, the mechanisms involved remain unclear. This study investigated whether the concentrations of interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) in plasma can to influence biochemical parameters of zinc in obese women. METHODS: Seventy-six pre-menopausal women, aged between 20 and 50 years, were divided into two groups: the case group, composed of obese women (n = 37) and the control group, composed of non-obese women (n = 39). Analysis of the plasmatic and erythrocytary zinc, and plasmatic cytokines were conducted by flame atomic absorption spectrophotometry and by ELISA, respectively. RESULTS: The plasmatic zinc and concentrations of IL-6 in plasma did not show significant differences between obese women and controls (p > 0.05). The erythrocytary zinc was 36.4±15.0µg/gHb in the case group, and 45.4±14.3µg/gHb (p = 0.025) in the control group. The concentrations of TNF-α in plasma were 42.0±11.9 pg/mL and 19.0±1.0 pg/mL in obese women and in controls, respectively (p < 0.001). The plasmatic zinc had a significant negative correlation with the values of TNF-α (r =-0.44, p = 0.015). CONCLUSION: Obese women presented lower concentrations of erythrocytary zinc than the control group. The study demonstrated a probable influence of the inflammatory process on metabolism of zinc in obese patients.

OBJETIVO: O estudo investigou a relação entre parâmetros do controle glicêmico, a zincemia e a atividade da enzima superóxido dismutase em pacientes diabéticos tipo 2. SUJEITOS E MÉTODOS: Setenta e três indivíduos, de 25 a 59 anos de idade, foram distribuídos em grupo caso (diabéticos tipo 2, n = 36) e grupo controle (n = 37). Foram analisados zinco plasmático e eritrocitário, atividade da enzima superóxido dismutase e parâmetros do controle glicêmico. RESULTADOS: A média de zinco plasmático foi 74,1 ± 10,7 µg/dL e 68,8 ± 9,6 µg/dL; de zinco eritrocitário foi 48,1 ± 9,5 µg/gHb e 41.2 ± 8.0 µg/gHb; e da atividade da superóxido dismutase foi 2248,9 ± 300,0 U/gHb e 2059,6 ± 285,4 U/gHb no grupo caso e grupo controle, respectivamente (p < 0,05). CONCLUSÃO: Os pacientes diabéticos tipo 2 mostram uma resposta positiva ao estresse oxidativo devido à zincemia adequada e ao aumento da atividade da superóxido dismutase, sendo essa enzima influenciada pela insulina sérica.

OBJECTIVE: This study assessed the relationship between the parameters of glycemic control, and zinc concentrations in blood and superoxide dismutase enzyme activity in type 2 diabetes patients. SUBJECTS AND METHODS: Seventy-three individuals, aged between 25 and 59 years, were divided into the experimental group (type 2 diabetes patients, n = 36) and control group (n = 37). Plasma and erythrocyte zinc concentrations, superoxide dismutase activity, and parameters of glycemic control were analyzed. RESULTS: Mean plasma zinc concentration was 74.1 ± 10.7 µg/dL and 68.8 ± 9.6 µg/dL, erythrocyte zinc concentration was 48.1 ± 9.5 µg/gHb and 41.2 ± 8.0 µg/gHb, and superoxide dismutase activity was 2248.9 ± 300.0 U/gHb and 2059.6 ± 285.4 U/gHb, in the experimental group and the control group, respectively (p < 0.05). CONCLUSION: Type 2 diabetes patients showed a positive response to oxidative stress due to adequate zinc concentration in blood and increased activity of superoxide dismutase, and the enzyme was influenced by serum insulin.

Este trabalho visa a contribuir com informações sobre a relação entre exercício físico, estresse oxidativo e zinco. A formação de espécies reativas de oxigênio durante o exercício pode contribuir para danos tissulares e celulares, prejudicando o desempenho do atleta. Podem amenizar esses efeitos alguns minerais, como o zinco, que atuam como cofator da enzima superóxido dismutase e na regulação da síntese da metalotioneína, proteínas importantes no sistema de defesa antioxidante. No exercício físico, ocorrem distúrbios na compartimentalização do zinco, com alterações da concentração desse mineral em compartimentos celulares. No entanto, os mecanismos envolvidos no comportamento metabólico do zinco bem como a participação do mineral na melhora do desempenho físico ainda não estão totalmente esclarecidos. Dessa forma, conclui-se que a distribuição do zinco em organismos submetidos ao estresse oxidativo e os efeitos da deficiência desse mineral na capacidade antioxidante durante o exercício ainda devem ser pesquisados mais profundamente.

The aim of this study is to provide information about the association between physical exercise, oxidative stress and zinc. The formation of reactive oxygen species during exercise may contribute to tissue and cell damage, hindering athletes' performance. Some minerals, such as zinc, mitigate these effects by acting as a cofactor of the enzyme superoxide dismutase and in the regulation of metallothionein synthesis - important proteins of the antioxidant defense system. During physical exercise, zinc compartmentalization may be impaired, that is, changes in the concentration of this mineral occur in cellular compartments. However, the mechanisms involved in the metabolism of zinc, as well as its improvement of physical performance, are not yet fully understood. Thus, further research on the distribution of zinc in organisms subjected to oxidative stress is needed, and also on how zinc deficiency affects the antioxidant capacity during exercise.

OBJETIVO: Determinar as concentrações plasmáticas e eritrocitárias de zinco em idosos portadores e não-portadores de catarata senil em um serviço oftalmológico especializado, em Teresina-Piauí. MÉTODOS: Estudo quantitativo, transversal e controlado, realizado no Hospital de Olhos Francisco Vilar, Piauí, Brasil. Participaram 56 idosos (37 mulheres, 19 homens) sem condições associadas a modificações nos níveis de zinco ou aumento do risco de catarata. Escore > II foi utilizado para definir a presença de catarata, de acordo com o Lens Opacities Classification System II. As concentrações de zinco foram determinadas por espectrometria de absorção atômica em chama. Análise estatística incluiu os testes t de Student e qui-quadrado e 0,05 como nível de significância. RESULTADOS: Catarata senil foi identificada em 58,9% dos participantes, predominando o tipo nuclear (51,8%), seguido pelo cortical (26,8%) e subcapsular posterior (8,9%). Deficiência de zinco no plasma (<70 μg/dL) e no eritrócito (<40 μg/gHb) foi constatada em 49,1% e 30,4% dos idosos, respectivamente. Não houve diferenças significativas entre portadores e não-portadores de catarata, independente do tipo, quanto às concentrações de zinco plasmático (p=0,165) ou eritrocitário (p=0,426). CONCLUSÃO: Deficiência de zinco no plasma ou eritrócito foi comum entre os idosos; porém, os dados indicam não haver diferenças significativas nos referidos parâmetros quanto à presença de catarata senil, independente do tipo.

PURPOSE: To determine plasma and erythrocyte zinc concentrations in elderly with and without senile cataract in a tertiary eye care center at Teresina-Piauí. METHODS: A quantitative, transversal and controlled study was developed at the Hospital de Olhos Francisco Vilar, Piauí, Brasil. Fifty-six elderly subjects (37 females, 19 males) with no known conditions that modify zinc blood levels or increase risk of cataract were included. A score >II was used to define cataract, according to Lens Opacities Classification System II. Plasma and erythrocyte zinc concentrations were determined by flame atomic absorption spectrometry. Statistical tests included Student's t and chi-square tests, with a probability level of 0.05 as significant. RESULTS: Senile cataract was present in 58.9% of the subjects. The most common type was nuclear (51.8%), followed by cortical (26.8%) and posterior subcapsular (8.9%). Zinc deficiencies in plasma (<70 μg/dL) and erythrocyte (<40 μg/gHb) were found in 49.1% and 30.4% of participants, respectively. There were no significant differences between elderly with or without cataract, regardless of type, in relation to plasma (p=0.165) or erythrocyte (p=0.426) zinc concentrations. CONCLUSION: Zinc deficiency in plasma or erythrocyte were common among the elderly. However, the data suggest that no significant differences exist between elderly with or without senile cataract, regardless of type, in relation to the referred parameters of zinc evaluation.

Este estudo relata os aspectos funcionais do zinco, bem como a participação desse mineral nas alterações metabólicas presentes em indivíduos portadores de Síndrome de Down. A maioria dos trabalhos realizados observou que o estado nutricional relativo ao zinco nesses pacientes está inadequado, com alterações no sistema antioxidante, imunológico e no metabolismo dos hormônios da tireóide. Estudos in vitro apontam que o zinco participa como cofator da enzima deiodinase tipo II na conversão periférica de Tiroxina em Triiodotironina, e que essa reação está diminuída em indivíduos portadores de Síndrome de Down, o que contribui para a manifestação de distúrbios, como o hipotireoidismo subclínico. As alterações na compartimentalização do zinco no organismo desses indivíduos também favorecem a expressão excessiva da enzima cobre/zinco (Cu/Zn) superóxido dismutase, com aumento do estresse oxidativo, e ainda alterações no sistema imune. Na Síndrome de Down, tem sido demonstrada melhora no metabolismo dos hormônios tireoidianos e na função imune, após a suplementação com zinco. Portanto, o papel metabólico do zinco na Síndrome de Down deve ser mais pesquisado, tendo em vista que esse mineral pode contribuir no controle das alterações metabólicas comumente presentes em indivíduos portadores dessa síndrome.

This study reports the functional aspects of zinc as well as its participation in the metabolic changes present in individuals with Down syndrome. Most of the studies performed observed that the nutritional status related to zinc in these patients is inadequate, with changes in the antioxidant and immunological systems and in the metabolism of thyroid hormones. In vitro studies show that zinc participates as a cofactor of the enzyme deiodinase type II in the peripheral conversion of thyroxin into triiodothyronine, and that this reaction is decreased in individuals with Down syndrome, contributing to the manifestation of disorders such as subclinical hypothyroidism. Changes in zinc compartmentation in the body of these individuals also favor an excessive expression of the copper/zinc enzyme (Cu/Zn) superoxide dismutase, with increased oxidative stress, and also changes in the immune system. In Down syndrome, zinc supplementation has been shown to improve thyroid hormone metabolism and immune function. Therefore, the metabolic role of zinc in Down syndrome should be further researched, knowing that this mineral can.