Effects of low-dose recombinant human erythropoietin treatment on cognitive performance

Introduction: High-dose recombinant human erythropoietin (rhEpo) has been shown to improve cognitive performance in both healthy volunteers and in patients suffering from diseases affecting the brain. The aim of this study was to examine whether administration of low-dose and even micro-dose rhEpo improves cognitive performance in healthy volunteers. Methods: We enrolled 25 healthy volunteers in a doubleblind, randomised, placebo-controlled study to receive either low-dose rhEpo (n = 8, 60 IU/kg/week), micro-dose rhEpo (n = 9, 20 IU/kg/week), or saline (n = 8) for 4 weeks. Two cognitive performance-tests, the Raven Standard Progressive Matrices (Raven) and the Number Finder (NUFI), were performed during the first and last day of the study period. Semi-structured interviews were conducted weekly and were coded according to a scale. Results: Subjects receiving micro-dose rhEpo improved significantly measured by the Raven score (p = 0.04), and subjects receiving low-dose rhEpo treatment improved significantly measured by the NUFI score (p = 0.047), whereas no improvement was found in experienced cognitive performance in any of the groups. We found no significant difference in either Raven, NUFI or self-reported results between the groups. Conclusions: In this small study, we found no significant effect of low-dose or micro-dose rhEpo on visual attention, cognitive performance in complex cognitive tasks or self-experienced cognitive performance compared with placebo. Funding: The Aase and Ejnar Danielsen’s Foundation. Danish Ministry of Science, Innovation and Higher Education.