The redox balance of healthy Brazilian adults is associated with GPX1 Pro198Leu and -602A/G polymorphisms, selenium status, and anthropometric and lifestyle parameters.

PURPOSE: Considering that oxidative stress is implicated in the pathogenesis and progression of different health conditions, we aimed to evaluate whether the redox balance of a healthy Brazilian population is associated with GPX1 polymorphisms, selenium status, lipid profile, and anthropometric and lifestyle parameters. METHODS: 343 healthy adults were assessed for redox balance markers [glutathione peroxidase (GPx) and superoxide dismutase (SOD) activity; malondialdehyde (MDA) and oxygen radical absorption capacity (ORAC)]; genotyped for the polymorphisms GPX1 Pro198Leu (rs1050450), -602A/G (rs3811699) and Arg5Pro (rs8179169); evaluated for selenium biomarkers (plasma, erythrocyte, and urine) and intake; and assessed for lipid profile. Anthropometric (BMI) and lifestyle data (physical activity, current smoking habit and alcohol consumption) were collected. Multivariable regression models were applied to investigate the possible associations. RESULTS: Although there were no differences in GPx activity according to GPX1 Pro198Leu and -602A/G polymorphisms, this redox balance marker was positively associated with erythrocyte selenium and negatively associated with the presence of a minor allele of Pro198Leu. SOD activity was positively associated with the presence of a minor allele for these polymorphisms. ORAC showed the same pattern among Leu and G carriers and was positively associated with Leu allele presence, BMI and alcohol intake. MDA was only associated negatively with the male sex and plasma selenium. CONCLUSIONS: Our findings suggest that the redox balance of a Brazilian healthy population is associated with GPX1 polymorphisms (Pro198Leu and -602A/G), selenium status, BMI, sex, smoking habit and alcohol consumption.

Effect of mineral status and glucocorticoid use on bone mineral density in patients with Crohn's disease.

OBJECTIVES: Crohn's disease (CD) is a condition that is characterized by chronic inflammation. The presence of multifactorial pathogenesis that results from inflammation is associated with low micronutrient consumption and glucocorticoid use, which may be related to bone health. This study aimed to evaluate the relationship between dietary mineral intake and glucocorticoid use in bone mineral density (BMD) in patients with CD. METHODS: A cross-sectional study of 62 patients with CD ages 20 y to 40 y measured their macro- and micronutrient intake with a 3-d food record. The lumbar spine and femoral neck BMDs were determined using a bone densitometry technique. The C-reactive protein (CRP) levels and erythrocyte sedimentation rate (ESR) values were also noted. RESULTS: Dietary intake of calcium, zinc, and magnesium was below the reference values but the phosphorus intake level was within the normal value range. Patients with osteopenia and osteoporosis accounted for 17.7% and 14.5%, respectively, of the total number of participants. Significant bone loss was found in 22.6% of patients taking glucocorticoid medications. BMD was significantly reduced and also observed in patients in the active phase of their disease. Zinc and calcium intakes were found to be correlated with reduced femoral neck BMD. The mean CRP and ESR values were above the normal ranges. Significant differences in age and ESR were observed between patients with normal and reduced BMD (P <0.05). CONCLUSIONS: Low calcium and zinc intake, glucocorticoid use, and active disease phase are favorable conditions for bone loss in patients with Crohn's disease.

Participação do zinco na resistência à insulina / Participation of zinc in insulin resistance

Essa revisão relata os aspectos etiológicos da resistência à insulina, bem como a participação do zinco nesse processo. O zinco participa de vias metabólicas que envolvem a síntese de proteínas, metabolismo de carboidratos, de lipídeos e de ácidos nucléicos. Esse mineral tem sido relacionado com a interação entre hormônios e seus receptores, e com melhoras no estímulo pós-receptor. Estudos in vitro apontam que a insulina pode se ligar com o zinco, melhorando a solubilidade deste hormônio nas células beta do pâncreas, e, ainda, pode aumentar a capacidade de ligação da insulina ao seu receptor. Na obesidade e resistência à insulina, têm sido detectadas alterações na concentração e na distribuição de zinco nos tecidos, bem como melhora da sensibilidade à insulina após a suplementação com esse mineral. Portanto, o papel metabólico do zinco na síndrome de resistência insulínica deve ser mais pesquisado, tendo em vista que esse mineral pode contribuir no controle das alterações metabólicas comumente presentes em pacientes obesos.

[Role of zinc in insulin resistance]. / Participação do zinco na resistência à insulina.

This review reports the etiological aspects of insulin resistance as well as the participation of zinc in this process. Zinc participates in the metabolic pathways involving protein synthesis, and the metabolism of carbohydrate, lipid and nucleic acid. This element has been associated with the interaction between hormones and their receptors and to the improvement in the post-receptor stimulus. In vitro studies show that insulin may form a complex with zinc improving the solubility of this hormone in the pancreatic beta cells and also increasing the binding ability of insulin to its receptor. Regarding obesity and insulin resistance, alterations in zinc concentration and distribution in tissues, as well as improvement in sensitivity to insulin after supplementation with this element, have been detected. Thus, the metabolic role of zinc in the insulin resistance syndrome should be further investigated having in mind that this element may contribute to the control of the usual metabolic alterations present in obese patients.