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.

Concentrações de cobre em mulheres obesas e sua relação com marcador da peroxidação lipídica / Copper concentrations in obese women and their relationship to lipid peroxidation marker

Introdução: Estudos atuais têm mostrado relação entre minerais antioxidantes e desordens bioquímicas envolvidas na patogênese da obesidade, em especial, a peroxidação lipídica. Nesse sentido, a literatura revela importância da atuação de elementos traços, a exemplo do cobre, na proteção contra a produção excessiva de radicais livres em indivíduos obesos. Objetivo: deste estudo foi avaliar as concentrações de cobre em mulheres obesas e sua relação com marcador da peroxidação lipídica. Metodologia: Estudo de natureza transversal, analítico e experimental envolveu 89 mulheres, com idade entre 20 e 50 anos, distribuídas em dois grupos: grupo controle (mulheres eutróficas, n=45) e grupo caso (obesas, n=44). As concentrações plasmáticas e eritrocitárias do cobre foram determinadas por espectrometria de absorção atômica. As concentrações plasmáticas das TBARS foram determinadas seguindo-se método descrito por Ohkawa, Ohishi e Yagi (1979), com adaptações. Resultados: A concentração das substâncias reativas ao ácido tiobarbitúrico foi significativamente maior no grupo caso em comparação com o grupo controle (p=0,001). O grupo caso apresentou concentrações inferiores de cobre plasmático e eritrocitário (p<0,05). Ambos os grupos apresentaram concentrações adequadas de cobre eritrocitário e plasmático. Não foi verificada correlação significativa entre o cobre plasmático e eritrocitário e parâmetros de adiposidade (p>0,05). Conclusão: Os resultados deste estudo indicam concentrações plasmáticas e eritrocitárias de cobre dentro da faixa de adequação, sendo que o grupo caso apresenta concentrações inferiores comparado ao grupo controle. O estudo não revelou correlação significativa entre o marcador de peroxidação lipídica e as concentrações de cobre plasmático e eritrocitário

Background: Current studies have shown a relationship between antioxidant minerals and biochemical disorders involved in the pathogenesis of obesity, especially lipid peroxidation. In this sense, the literature reveals importance of the performance of trace elements, such as copper, in the protection against the excessive production of free radicals in obese individuals. Objective: was to evaluate how the associations of obese women and their interface with lipid peroxidation. Methods: Cross-sectional, analytical and experimental involved 89 women, aged between 20 and 50 years, divided into two groups: control group (eutrophic women, n = 45) and case group (obese, n = 44). As plasma and erythrocyte concentrations of copper and determined by atomic absorption spectrometry. Plasma concentrations of TBARS were determined following the method described by Ohkawa, Ohishi and Yagi (1979), with adaptations. Results: The concentration of the reactive substances to thiobarbituric acid was significantly higher in the case group compared to the control group (p = 0,001). The case group had lower concentrations of plasma and erythrocyte copper (p <0,05). Both groups had adequate concentrations of erythrocyte and plasma copper. There was no significant correlation between plasma and erythrocyte copper and adiposity parameters (p> 0,05). Conclusion: From the results of this study, it can be concluded that the participants of the study have plasma and erythrocyte copper concentrations within the adequacy range, and the case group presents lower concentrations compared to the control group. In addition, no significant correlation was found between the lipid peroxidation marker and the plasma and erythrocyte copper concentrations

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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

Role of Magnesium in Oxidative Stress in Individuals with Obesity.

Adipose tissue is considered an endocrine organ that promotes excessive production of reactive oxygen species when in excess, thus contributing to lipid peroxidation. Magnesium deficiency contributes to the development of oxidative stress in obese individuals, as this mineral plays a role as an antioxidant, participates as a cofactor of several enzymes, maintains cell membrane stability and mitigates the effects of oxidative stress. The objective of this review is to bring together updated information on the participation of magnesium in the oxidative stress present in obesity. We conducted a search of articles published in the PubMed, SciELO and LILACS databases, using the keywords 'magnesium', 'oxidative stress', 'malondialdehyde', 'superoxide dismutase', 'glutathione peroxidase', 'reactive oxygen species', 'inflammation' and 'obesity'. The studies show that obese subjects have low serum concentrations of magnesium, as well as high concentrations of oxidative stress marker in these individuals. Furthermore, it is evident that the adequate intake of magnesium contributes to its appropriate homeostasis in the body. Thus, this review of current research can help define the need for intervention with supplementation of this mineral for the prevention and treatment of disorders associated with this chronic disease.

Dietary intake of vitamin D and its relation to insulin resistance in obese women / Ingestão dietétíca de vitamina D e sua relação com a resistência à insulina em mulheres obesas

The aim of this study was to assess the relation between dietary intake of vitamin D and insulin resistance in obese and nonobese women. This cross-sectional study included 93 women, aged between 20 and 50 years, who were subdivided into two groups: the obese group (n = 46) and the agematched control group (n = 47). Vitamin D and calcium intake was monitored using 3-day food records and Dietpro software version 5.1. Measurements of serum glucose and serum insulin were based on an enzymatic colorimetric method and a chemiluminescence assay, respectively. Insulin resistance was assessed by means of homeostasis model assessment of insulin resistance (HOMA-IR). The median values of vitamin D content in the diet were found to be lower than those recommended, although there was a significant difference between groups (p < 0.001). The mean values of calcium intake were found to be above the recommendations, although there was no significant difference between the groups (p > 0.05). The values of serum glucose, serum insulin, and HOMA-IR were higher in obese women than in the control group. The correlation analysis indicated that the association between the dietary intake of vitamin D and insulin resistance was not significant. The results of this study indicate that dietary vitamin D does not influence parameters of glycemic control in obese women (AU)

O objetivo do estudo foi avaliar a relação entre a ingestão dietética de vitamina D e resistência à insulina em mulheres obesas e não obesas. Este estudo transversal incluiu 93 mulheres, com idades entre 20 e 50 anos, que foram subdivididos em dois grupos: obesos (n = 46) e o grupo controle pareados por idade (n = 47). A ingestão de vitamina D e cálcio foi estimada por meio dos registros alimentares de 3 dias e analisada pelo software DietPro versão 5.1. As mensurações séricas de glicose e insulina foram baseadas em um método colorimétrico enzimático e um ensaio de quimiluminescência, respectivamente. A resistência à insulina foi avaliada por meio do modelo de avaliação da homeostase da resistência à insulina (HOMA-IR). Os valores médios do teor de vitamina D na dieta foram mais baixos do que os recomendados, embora houvesse uma diferença significativa entre os grupos (p <0,001). Os valores médios de ingestão de cálcio estavam acima das recomendações, apesar de não haver diferença significativa entre os grupos (p> 0,05). Os valores de glicose sérica, insulina sérica, e HOMA-IR foram maiores em mulheres obesas que no grupo de controle. A análise de correlação indicou que a associação entre a ingestão de vitamina D e resistência à insulina não foi significativa. Os resultados deste estudo indicam que a vitamina D na dieta não influencia os parâmetros de controle glicêmico em mulheres obesas (AU)

Teor de Vitamina D na dieta e sua relação com marcador de inflamação em pacientes renais crônicos hemodialisados / Vitamin D content in the diet and its relation to inflammation marker in renal chronic Hemodialysis patients

Introdução: Estudos têm mostrado deficiência de vitamina D em dietas consumidas por doentes renais crônicos em hemodiálise, o que parece contribuir para a inflamação nesses pacientes. Objetivo: O estudo avaliou a relação entre o teor de vitamina D na dieta e as concentrações séricas da proteína C reativa em doentes renais crônicos em hemodiálise. Métodos: Estudo de natureza transversal com caso e controle, envolvendo 93 indivíduos, com idade entre 20 e 60 anos, sendo distribuídos em dois grupos: grupo controle (saudáveis, n=54) e grupo caso (doentes renais, n=39). A ingestão de vitamina D foi avaliada por meio de registro alimentar de três dias, utilizando o programa Dietpro versão 5.i. A proteína C reativa sérica foi analisada pelo método de quimioluminescência. Os dados foram analisados no programa estatístico SPSS for Windows 20.0. Resultados: Os valores médios da ingestão de vitamina D estavam inferiores às recomendações, sem diferença estatística entre os grupos (p>0,05). As concentrações séricas médias da proteína C reativa foram 2,02 ± 1,14 mg/L para os doentes renais crônicos e 1,70 ± 1,41 mg/L para o grupo controle, com diferença significativa entre os grupos (p0,05). Conclusão: Portanto, os pacientes renais crônicos ingerem alimentos com teor baixo de vitamina D. Porém, o estudo não revela correlação entre o teor dietético dessa vitamina e as concentrações séricas da proteína C reativa, sugerindo que a ingestão de vitamina D parece não influenciar no processo inflamatório presente nesses pacientes (AU)

Introduction: Studies have shown vitamin D deficiency in diets consumed by hemodialysis patients, which seems to contribute to inflammation in these patients. Objective: To study the relationship between vitamin D content in the diet and serum concentrations of C-reactive protein in hemodialysis patients. Methods: Transversal study with cases and controls, involving 93 individuals, aged between 20 and 60 years, divided into two groups: control group (healthy, n = 54) and case group (kidney patients, n = 39). Intake of vitamin D was assessed by three days food diaries using the software DietPro version 5.i. Serum C-reactive protein was analyzed by chemi luminescence. The data were analyzed with the software SPSS for Windows 20.0. Results: The mean values of vitamin D intake were lower than those recommendations, with no statistical difference between the groups (p> 0.05). The average serum concentrations of C-reactive protein were 2.02 ± 1.14 mg/L for hemodialysis patients and 1.70 ± 1.41 mg/L for the control group, with significant difference between groups (p 0.05). Conclusion: Therefore, chronic renal patients eating foods low in vitamin D. However, the study reveals correlation between dietary content of this vitamin and serum concentrations of C-reactive protein, suggesting that vitamin D intake does not influence the inflammatory process present in these patients (AU)