Selenium, an essential trace element for thyroid and iodine metabolism with antioxidant and anti-inflammatory properties, is present in different forms in the human body. The majority of selenium is found as selenoproteins and glutathione peroxidase and only less than 1% in the free form. The recommended dietary daily requirement for healthy adult patients ranges between 60 and 100 mcg/day.1
Despite previous work examining the effects of selenium in patients with sepsis and studies showing that patients in the intensive care unit (ICU) with systematic inflammatory response syndrome (SIRS) and severe sepsis have a 40% lower selenium level compared to those without SIRS, no meta-analysis has examined the effect of selenium on mortality in critically ill patients.2-12
In a newly published meta-analysis13, the authors sought to determine whether selenium compared to placebo reduces mortality in patients with sepsis. Databases searched include: The Cochrane Central Register of Controlled Trials, Medline, EMBASE, SciFinder and Clinicaltrials.gov. A priori was defined as subgroup analysis according to selenium dose (i.e., 500 mcg or less per day vs. more than 500 mcg per day).
Nine trials with a total of 792 patients enrolled were included. Selenium supplementation at higher than daily requirements was associated with lower mortality (OR: 0.73; 95% CI, 0.54-0.98; p = 0.03; I2 = 0%). The authors however did not find a difference in terms of secondary outcomes including ICU length of stay and nosocomial pneumonia. The authors also note that there is significant heterogeneity among trials in terms of adverse event reporting which prevented pooling of results.
In conclusion, it does appear that selenium might have a role in patients with sepsis syndromes. However, further studies are needed to confirm the effect on mortality. We are awaiting the results of two ongoing clinical studies investigating the effect of selenium alone and in combination with other elements on mortality.
1. Rayman MP. The importance of selenium to human health. Lancet.
2. Forceville X, Vitoux D, Gauzit R, et al. Selenium, systemic immune response syndrome, sepsis, and outcome in critically ill patients. Crit Care Med.
3. Manzanares W, Biestro A, Torre MH, et al. High-dose selenium reduces ventilator-associated pneumonia and illness severity in critically ill patients with systemic inflammation. Intensive Care Med.
4. Forceville X, Laviolle B, Annane D, et al. Effects of high doses of selenium, as sodium selenite, in septic shock: A placebo-controlled, randomized, double-blind, phase II study. Crit Care.
5. Heyland DK, Dhaliwal R, Suchner U, et al. Antioxidant nutrients: A systematic review of trace elements and vitamins in the critically ill patient. Intensive Care Med.
6. Angstwurm MW, Engelmann L, Zimmermann T, et al. Selenium in Intensive Care (SIC): Results of a ...