The Effect of Selenium Supplementation on Acute Phase Reactants and Thyroid Function Tests in Hemodialysis Patients

BACKGROUND: Selenium deficiency is a common problem in patients with chronic kidney disease (CKD). This micronutrient has anti-inflammatory and anti-oxidant effects. Selenium is also found in high concentrations in the thyroid gland. OBJECTIVES: To determine the effect of selenium supplementation on thyroid function tests and acute phase reactants in hemodialysis patients. PATIENTS AND METHODS: In this double-blinded randomized clinical in 3 months, 64 hemodialysis patients with selenium deficiency were divided into experimental (received selenium supplementation; 32 cases) or control group (received placebo; 32 cases). Erythrocyte sedimentation rate (ESR), ferritin, quantitative C-reactive protein (CRP) and thyroid function tests (TFTs) including thyroid stimulating hormone (TSH), T3 resin uptake (T3RU), and free T4 were measured before and after the intervention and compared between experimental and control groups. RESULTS: At baseline, no significant difference was found between experimental and control groups regarding CRP, ESR and ferritin serum levels. Likewise, after intervention, no significant difference was found between experimental and control groups for CRP (14.77 ± 17.93 vs. 18.29 ± 21.56 mg/L), ESR (32.90 ± 32.62 vs. 33.91 ± 31.15 mm/h) and ferritin (528.6 ± 423.07 vs. 519.52 ± 345.59 ng/mL). At baseline, no significant difference was found between experimental and control groups regarding TFTs. Likewise, after intervention, no significant difference was found between experimental and control groups for TSH (3.7 ± 2.22 vs. 2.84 ± 1.88 µU/mL), free T4 (7.19 ± 1.98 vs. 7.02 ± 1.87 µg/dL) and T3RU (30.04 ± 2.28% vs. 29.2 ± 1.98%). CONCLUSIONS: Oral selenium supplementation for three months did not have any significant effect on thyroid function tests or acute phase reactants.