Naturally Occurring Compounds: New Potential Weapons against Oxidative Stress in Chronic Kidney Disease
BACKGROUND Malnutrition is highly prevalent in hemodialysis (HD) patients. These patients have high levels of oxidative stress and inflammation which can subsequently induce malnutrition. Selenium levels have been found to be decreased in HD patients. As selenium deficiency leads to oxidative stress and inflammatory response, the aim of this study was to evaluate the effects of selenium supplementation on oxidative and inflammatory markers and the nutritional status of HD patients. METHODS In this randomized double-blind placebo-controlled trial, 80 patients on stable HD for at least 3 months without any acute illness or active infections were randomly allocated to two equal groups to receive one selenium (200 µg) or placebo capsule daily for 12 weeks. Serum levels of lipoproteins, malondialdehyde (MDA), interleukin-6 (IL-6), high-sensitivity C-reactive protein (HSCRP), homocysteine, ferritin and transferrin as well as the subjective global assessment (SGA) score, malnutrition-inflammation score (MIS) and hemoglobin (Hb) levels were measured at the baseline and at the end of the treatment phase. The primary outcome was a change in the nutritional status measured by the SGA score from the baseline towards the end of the treatment phase of the study. RESULTS The SGA score and MIS decreased significantly in the selenium group compared to the placebo group (P < 0.001 for both). Moreover, serum levels of MDA decreased significantly in the selenium group compared with increasing levels in the placebo group (P < 0.001). Selenium supplementation also hindered an increase in IL-6 levels compared with the placebo group (P = 0.016). There were no significant differences between the selenium and placebo groups in terms of changes in serum levels of lipoproteins, HSCRP, homocysteine, ferritin and transferrin or Hb levels. CONCLUSIONS This study shows that selenium may be an effective complementary supplement for reducing the severity of malnutrition in HD patients through alleviating oxidative stress and inflammation.