The favourable effects of long-term selenium supplementation on regression of cervical tissues and metabolic profiles of patients with cervical intraepithelial neoplasia: a randomised, double-blind, placebo-controlled trial (Publication with Expression of Concern. See vol. 127, pg. 152, 2022)

This study was conducted to assess the effects of long-term Se administration on the regression and metabolic status of patients with cervical intraepithelial neoplasia grade 1 (CIN1). This randomised, double-blind, placebo-controlled trial was carried out among fifty-eight women diagnosed with CIN1. To diagnose CIN1, we used specific diagnostic procedures of biopsy, pathological diagnosis and colposcopy. Patients were randomly assigned to two groups to receive 200 mu g Se supplements as Se yeast (n 28) or placebo (n 28) daily for 6 months. After 6 months of taking Se supplements, a greater percentage of women in the Se group had regressed CIN1 (88.0 v. 56.0%; P= 0.01) compared with those in the placebo group. Long-term Se supplementation, compared with the placebo, resulted in significant decreases in fasting plasma glucose levels (-0.37 (SD 0.32) v. +0.07 (SD 0.63) mmol/l; P= 0.002), serum insulin levels (-28.8 (SD 31.2) v. +13.2 (SD 40.2) pmol/l; P < 0.001), homeostatic model assessment of insulin resistance values (-1.3 (SE 1.3) v. +0.5 (SE 1.4); P < 0.001) and a significant elevation in quantitative insulin sensitivity check index (+0.03 (SD 0.03) v. -0.01 (SD 0.01); P < 0.001). In addition, patients who received Se supplements had significantly decreased serum TAG (-0.14 (SD 0.55) v. +0.15 (SD 0.38) mmol/l; P = 0.02) and increased HDL-cholesterol levels (+ 0.13 (SD 0.21) v. -0.01 (SD 0.15) mmol/l; P=0.003). In addition, compared with the placebo group, there were significant rises in plasma total antioxidant capacity (+186.1 (SD 274.6) v. +42.8 (SD 180.4) mmol/l; P=0.02) and GSH levels (+65.0 (SD 359.8) v. -294.2 (SD 581.8) mu mol/l; P=0.007) and a significant decrease in malondialdehyde levels (-1.5 (SD 2.1) v. + 0.1 (SD 1.4) mu mol/l; P=0.001) among those who took Se supplements. Overall, taking Se supplements among patients with CIN1 led to its regression and had beneficial effects on their metabolic profiles.