Iron, calcium and phosphorus mineral profile in chronic renal patients on hemodialysis

The main goal of this study was to verify the association between serum and dietary concentrations of calcium, phosphorus and iron, and to determinate whether patients with kidney disease undergoing hemodialysis had inadequacy in dietary intake. We conducted a descriptive cross-sectional study that evaluated 40 patients undergoing hemodialysis. Food consumption was determined by the 24-hour recall. The optical technology method was used to obtain hemoglobin and hematocrit concentrations. Serum levels of iron, calcium and phosphorus were determined by dry chemistry. We observed insufficient consumption of energy, macronutrients and minerals. Energy intake of patients with longer hemodialysis was higher. The sample presented hypocalcemia, hyperphosphatemia (except in the group ≥8 years of hemodialysis), higher iron concentrations and lower hemoglobin and hematocrit values. The serum levels of minerals were not affected by dietary intake. There was a significant correlation between dietary phosphorus and calcium in patients undergoing hemodialysis for more than 8 years, those over 60 years old and, between calcium and phosphorus normal levels in patients over 60 years old. Hemoglobin, hematocrit and mineral serum levels were similar regardless of age and hemodialysis time. It was concluded that inadequacies of minerals reflected deregulation among metabolism and the pathophysiological changes inherent to Chronic Kidney Disease.

El objetivo principal de este estudio fue verificar la asociación entre las concentraciones séricas y dietéticas de calcio, fósforo y hierro, y determinar su ingesta dietética inadecuada en pacientes con enfermedad renal sometidos a hemodiálisis. Se trató de un estudio descriptivo transversal que evaluó a 40 pacientes en hemodiálisis. El consumo de alimentos se determinó mediante el recordatorio de 24 horas. Se utilizó el método de tecnología óptica para obtener concentraciones de hemoglobina y hematocrito. Los niveles séricos de hierro, calcio y fósforo se determinaron mediante química seca. El estudio mostró un consumo insuficiente de energía, macronutrientes y minerales. La ingesta energética de los pacientes con hemodiálisis más prolongada fue mayor. La muestra presentó hipocalcemia, hiperfosfatemia (excepto en el grupo ≥8 años de hemodiálisis), mayor concentración de hierro y menores valores de hemoglobina y hematocrito. Los niveles séricos de minerales no se vieron afectados por su ingesta dietética. Hubo una correlación significativa entre el fósforo dietético y el calcio en los pacientes en hemodiálisis durante más de 8 años y los mayores de 60 años y, también, entre los niveles normales de calcio y fósforo en los pacientes mayores de 60 años. Los niveles séricos de hemoglobina, hematocrito y minerales fueron similares independientemente de la edad y el tiempo de hemodiálisis. Se concluyó que las deficiencias de los minerales parecen reflejarse en la desregulación de su metabolismo y los cambios fisiopatológicos inherentes a la Enfermedad Renal Crónica.

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.

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.

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.

Efeito de prebióticos e probióticos na microbiota intestinal e nas alterações metabólicas de indivíduos obesos / Effect of prebiotics and probiotics on the gut microbiota and metabolic changes in obese individuals

Currently, the growing prevalence of obesity and its comorbidities is a major public health problem. The intestine is a complex organ that has been increasingly studied in obesity because of its ability to signal pathways involved in the pathophysiology of this disease. OBJECTIVES: This review aimed to clarify the main effects of probiotics and prebiotics on the intestinal microbiota and metabolic abnormalities of obese subjects. Data source: The survey of articles was conducted at PubMed database using the following keywords: 'obesity', 'gut microbiota', 'probiotic' and 'prebiotic' involving scientific works published between 2009 and 2014. Data synthesis: We found that the intestinal microbiota can be modulated by diet, and it acts on the control of food intake by interacting with receptors and enzymes that interfere in the metabolic changes arising from obesity and in the modulation of the inflammatory response. Animal research has shown positive results with the use of prebiotics and probiotics as adjuncts in the treatment of obesity; however, results with humans still present controversial data. CONCLUSIONS: Evidence of the relationship between diet, microbiota and immune system shows that a better understanding of the role of microbiota in obesity leads to new perspectives in the development of therapies for this disease

A crescente prevalência da obesidade e suas comorbidades tem sido um dos principais problemas de saúde pública atualmente. O intestino é um órgão complexo, cada vez mais estudado na obesidade pela sua capacidade de sinalizar vias metabólicas envolvidas na fisiopatologia dessa doença. OBJETIVO: Esclarecer os principais efeitos de probióticos e prebióticos nas alterações metabólicas e da microbiota intestinal de indivíduos obesos. Fonte de dados: O levantamento dos artigos foi realizado na base de dados Pubmed, utilizando os descritores: obesity, gut microbiota, probiotic e prebiotic envolvendo publicações no período de 2009 a 2014. Síntese dos dados: Constatou-se que a microbiota intestinal pode ser modulada pela dieta e atuar no controle da ingestão alimentar interagindo com receptores e enzimas que interferem nas alterações metabólicas decorrentes da obesidade e na modulação da resposta inflamatória. Pesquisas com animais mostraram resultados positivos do uso de prebióticos e probióticos como coadjuvantes no tratamento da obesidade, contudo, os resultados com humanos ainda apresentam dados controversos. CONCLUSÕES: Evidências da relação entre dieta, microbiota e sistema imune demonstram que a melhor compreensão do papel da microbiota na obesidade leva a novas perspectivas no desenvolvimento de terapias para a obesidade