Anemia is an inevitable complication of hemodialysis, and the primary cause is
erythropoietin deficiency. After diagnosis, treatment begins with an
erythropoiesis-stimulating agent (ESA). However, some patients remain anemic
even after receiving this medication. This study aimed to investigate the
factors associated with resistance to recombinant human erythropoietin therapy
with epoetin alfa (αEPO). We performed a prospective, longitudinal study of
hemodialysis patients receiving treatment with αEPO at our reference hospital
from July 2015 to June 2016. Clinical data was collected, and the response to
αEPO treatment was evaluated using the erythropoietin resistance index (ERI).
The ERI was defined as the weekly weight-adjusted αEPO dose (U/kg per
week)/hemoglobin level (g/dL). A longitudinal linear regression model was fitted
with random effects to verify the relationships between clinical and laboratory
data and ERI. We enrolled 99 patients (average age, 45.7 (±17.6) years; male,
51.5%; 86.8% with hypertension). The ERI showed a significant positive
association with serum ferritin and C-reactive protein, percentage interdialytic
weight gain, and continuous usage of angiotensin receptor blocker (ARB)
hypertension medication. The ERI was negatively associated with serum iron and
albumin, age, urea reduction ratio, and body mass index. Our findings indicate
that resistance to αEPO was related to a low serum iron reserve, an inflammatory
state, poor nutritional status, and continuous usage of ARBs.