The relationship between comorbidity, anemia and response to erythropoiesis-stimulating agents in chronic hemodialysis

SUMMARY Introduction: Patients treated with haemodialysis have a high prevalence of co-morbidity that induces a elevate mortality risk. On the other hand, these patients have anaemia whose treat- ment is based in eritropoyesis stimulating agents. To date there are not enough studies to determine if co-morbidity alters eryth- ropoietin response and the relationship between co-morbidity, response to treatment of anaemia and resistance to erythro- poiesis-stimulating agents. Objectives: We have the following Objectives: i) to study the prevalence of associated diseases in patients treated with haemodialysis in our Hospital Unit and to evaluate the co-morbidity Charlson Index; ii) to know the degree of anaemia control, dose and response to erythropoiesis-stimu- lating agents, and iii) to determine the relationship with co- morbidity and anaemia treatment. Patients and methods: We designed a retrospective study in stable haemodialysis treated patients. We calculated the Charlson co-morbidity index adjus- ted to age and we analysed levels of haemoglobin in the 6 months before study, dose of erythropoiesis-stimulating agents and its resistance index defined as doses of erythropoiesis-sti- mulating agents/weight (kg)/week/haemoglobin (g/dL). The dif- ferent variables included in Charlson index were considered as independent variables and the index to repose to erythropoiesis- stimulating agents as a dependent variable, using bivariant and multivariate statistical analysis. Results: We included 58 patients (31 males and 27 females), median age of 69.5 years (range 24- 88), mean haemodialysis 83,7 months. Mean Charlson index was 7.4 ± 2.8 (range 2-13). Comorbidity-age Charlson index was 2 in 3.4% of patients; 10.3% had 3 or 4 points; 43.2% between 5 and 7 and 43.1% 8 or more. Mean haemoglobin levels was 11.7±1.2 g/dL. Mean erythropoiesis-stimulating agents dose was 163.7 ± 114.5 IU/kg/week and resistance index 14.1 ± 9.7. Most of patients (57%) had a IRE value higher than 10. Forteen pa- tients (24%) had haemoglobin less than 11 g/dL, and 3 of them (5.1%) received erythropoiesis-stimulating agents more than 300 IU/kg/week. Nine subjects (15.5%) was treated with high dose of erythropoiesis-stimulating agents (> 300 IU/kg/week): 3 of them had Hb ≥ 11 g/dL and 6 had Hb < 11 g/dL. We did not found that the intensity of Charlson index is related with the degree of anae- mia control or response to erythropoiesis-stimulating agents. Conclusions: Althought in our study the comorbidity index is high and the response to erythropoiesis-stimulating agents is inade- quate, there is not relationship between these conditions.