Prevalence, treatment status, and predictors of anemia and erythropoietin hyporesponsiveness in Japanese patients with non-dialysis-dependent chronic kidney disease: a cross-sectional study.

BACKGROUND

Hyporesponsiveness to erythropoiesis-stimulating agents (ESAs) has been highlighted as a potential risk factor for cardiovascular disease in patients with chronic kidney disease (CKD).

METHODS

We assessed cross-sectionally the prevalence, associated factors, and treatment status of anemia and ESA hyporesponsiveness in 4460 non-dialysis-dependent CKD patients enrolled in a multicenter cohort in Japan. Anemia was defined as a hemoglobin (Hb) level of less than 11 g/dL or receiving ESA therapy. ESA hyporesponsiveness was defined by the erythropoietin-resistance index (ERI), which was the erythropoietin dose per week divided by body weight and Hb level (U/kg/week/g/dl).

RESULTS

Of the 4460 patients, 1050 (23.5%) had anemia. ESAs were administered to 626 patients, reaching a percentage of 57.5% of patients with stage G5 CKD. However, the ESA treatment rate was only 49.0% in patients with a hemoglobin level of < 11 g/dL. The proportion of patients receiving iron supplementation was lower than that of patients receiving ESAs regardless of CKD stage or hemoglobin level, and a significant proportion of patients did not receive iron supplementation, even those with iron deficiency. The ERI increased with CKD stage progression, and the multiple regression analysis showed that age, female sex, body mass index, cholesterol, glomerular filtration rate, and intact parathyroid hormone level were independent contributors.

CONCLUSIONS

Our findings demonstrate that many Japanese patients with non-dialysis-dependent CKD receiving ESAs fail to maintain adequate hemoglobin levels. These results suggest the need for interventions for ESA hyporesponsiveness factors in addition to iron supplementation.