[Anemia in chronic kidney disease]

Anemia is almost unavoidable in the last stages of chronic kidney disease. It is defined as a condition where hemoglobin concentration is below 2 standard deviations from the mean hemoglobin level of the general population, corrected for age and sex (typically, hemoglobin < 13 g/dL in adults and 12 g/dL in women). Although the cause is multi-factorial, the most known is inadequate erythropoietin production. Anemia has been associated with poor prognosis in patients with several conditions such as cancer, chronic kidney disease and congestive heart failure. Treatment with erythropoiesis-stimulating agents, such as erythropoietin, is a logical strategy that has enabled clinical improvement and reduced transfusion requirements for the patients; however, total correction of anemia with erythropoiesis-stimulating agents has demonstrated an increase in the risk of mortality or cardiovascular complications associated with these agents. In randomized trials, the achievement of normal or nearly normal hemoglobin levels is not associated with improved survival and reduced cardiovascular risk; however the ideal hemoglobin level with the use of erythropoiesis-stimulating agents seems to be problematic. More information is needed in order to obtain definite conclusions; in the meantime, using the lowest possible dose of erythropoietin seems to be the most prudent approach.