Effects of Selenium Supplementation on Asymmetric Dimethylarginine and Cardiometabolic Risk Factors in Patients with Polycystic Ovary Syndrome

Polycystic ovary syndrome (PCOS) is characterized by various reproductive and cardiometabolic disorders. Asymmetric dimethylarginine (ADMA) is associated with cardiovascular, metabolic, and hormonal status. Selenium, a micronutrient with antioxidant properties, could affect multiple physiological pathways. This study aimed to investigate the effect of selenium supplementation on ADMA, cardiometabolic risk factors, and hormonal status in women with PCOS. In this randomized, double-blind, placebo-controlled clinical trial, 66 women with PCOS, aged 18–45 years, were randomly assigned to receive either 200 μg/day selenium or placebo, for 12 weeks. Circulating concentrations of ADMA, testosterone, sex hormone-binding globulin (SHBG), lipid profiles, and glycemic parameters were assessed at baseline and following supplementation. ADMA concentration decreased significantly compared to baseline values (85.14 ± 75 to 56.4 ± 38.64 ng/l, p = 0.02) in the selenium group. This change was marginally significant compared with the placebo group (28.74 ± 68.63 vs. − 1.77 ± 52.88 ng/l, p = 0.056). Serum testosterone levels declined significantly in the intervention compared to the placebo group (0.01 ± 0.17 vs. − 0.08 ± 0.18 ng/ml, p = 0.038). Pre- to post-Apo-B100/Apo-A1 ratio declined considerably in the intervention group (0.72 ± 0.16 to 0.65 ± 0.16, p = 0.003). No further differences were observed in SHBG, lipid profiles, Apo-A1, Apo-B100, Apo-B100/Apo-A1 ratio, and glycemic control between the two groups at the end of the study. Selenium supplementation for 12 weeks had beneficial effects on reduction of circulating ADMA and total testosterone levels in women with PCOS. No significant improvements were seen in other cardiometabolic risk factors. The effects of selenium supplementation on hormonal, reproductive, and cardiometabolic disorders, considering the potential mediating role of ADMA, should be further investigated.