Association between selenium biomarkers and insulin resistance in women with obesity: A case-control study.

Background: Although literature demonstrates controversial results regarding the association between selenium and glucose metabolism, no studies have specifically targeted a population with obesity even though this group is vulnerable to insulin resistance.

Aim: To evaluate the association between selenium biomarkers and insulin resistance in women with obesity.

Methods: This case-control study recruited 84 women with obesity and 129 with healthy weight (control). Selenium intake was assessed by 3-day food record. Selenium concentration in plasma, erythrocyte, and urine was assessed by inductively coupled plasma optical emission spectrometry. Serum glucose, insulin, and glycated hemoglobin (HbA1c) were assessed in a fasting blood sample. Homeostasis Model Assessment of Beta Cell Function (HOMA-β) and Homeostasis Model Assessment of Insulin Resistance were calculated according to standard methods.

Results: Women with obesity had higher dietary selenium intake in comparison to the control group (p < 0.001). Further, the plasma and erythrocyte concentrations were lower in individuals with obesity (p < 0.001), while selenium in urine was higher (p < 0.001) than in controls. No significant differences in insulin resistance markers were observed between groups. Selenium intake was positively associated with HOMA-β in both groups. In women with obesity, selenium intake was also positively associated with insulin and HbA1c, while in the controls the clearance of selenium was negatively associated with insulin and HbA1c. There was a positive correlation between dietary selenium intake, fasting insulin, HbA1c, and HOMA-β (p < 0.05).

Conclusions: Women with obesity present impaired selenium metabolism. Further, we observed an association between dietary selenium and markers of insulin resistance, which may reflect the possible negative action of selenium on insulin signaling.