Selenium Concentrations and Their Relation to Insulin Resistance in Obese Women

Several studies have shown the importance of selenium in preventing important metabolic disorders associated with obesity, such as chronic inflammation, oxidative stress and insulin resistance. However, the results of these studies are still controversial. Thus, this study aimed to evaluate selenium concentrations and their relation to insulin resistance in obese women. A cross-sectional study involving 213 women divided into a case group (obese women, n = 84) and a control group (eutrophic women, n = 129). Energy, macronutrient and selenium intake were obtained from the three-day food record. Evaluation of selenium in plasma, erythrocyte and urine was performed by inductively coupled plasma optical emission spectrometry. Serum glucose concentrations were determined according to the colorimetric enzymatic method. Fasting insulin and glycated hemoglobin were analyzed according to the chemiluminescence method. The mean values of dietary selenium intake (µg/kg/day) by obese women were lower than the control group (p < 0.001). Plasma and erythrocyte concentrations had reduced values in the obese women (p < 0.001), while selenium concentrations found in urine were higher (p  0.05). There was a positive correlation between dietary selenium intake (µg/day), fasting insulin, glycated hemoglobin and HOMA-β, as well as between dietary intake (µg/kg/day), fasting insulin and HOMA-β (p < 0.05). The evaluated women with obesity present alterations in the nutritional status regarding selenium. In addition, it evidences a positive relationship between dietary selenium and markers of glycemic control, which may reflect the possible negative action of selenium on insulin action signaling.