Kidney Week

Abstract: FR-PO0617

Association Between Serum 1,25-Dihydroxyvitamin D Levels and Erythropoiesis-Stimulating Agent Hyporesponsiveness in Patients with Predialysis CKD

Session Information

• Anemia: Global Burden, Disease Interactions, and Emerging Therapeutic Paradigms
  October 23, 2026 | Location: Exhibit Hall A, Convention Center
  Abstract Time: 10:00 AM - 12:00 PM

Category: Anemia and Iron Metabolism

• 200 Anemia and Iron Metabolism

Authors

• Lee, Dong Won, Pusan National University Yangsan Hospital, Yangsan-si, Gyeongsangnam-do, Korea (the Republic of)

Dong Won Lee, MD, PhD

• On, Jin hyeon, Pusan National University Yangsan Hospital, Yangsan-si, Gyeongsangnam-do, Korea (the Republic of)

Jin hyeon On, MD

• Dasol, Choi, Pusan National University Yangsan Hospital, Yangsan-si, Gyeongsangnam-do, Korea (the Republic of)

Choi Dasol, MD

• Kim, Il Young, Pusan National University Yangsan Hospital, Yangsan-si, Gyeongsangnam-do, Korea (the Republic of)

Il Young Kim, MD

• Lee, Soo Bong, Pusan National University Yangsan Hospital, Yangsan-si, Gyeongsangnam-do, Korea (the Republic of)

Soo Bong Lee, MD, PhD

Background

Erythropoiesis-stimulating agents (ESAs) are widely used to treat anemia in patients with chronic kidney disease (CKD). However, inadequate response to ESA therapy remains a major challenge in the management of CKD-related anemia. Although vitamin D deficiency has been associated with anemia, the relationship between serum 1,25-dihydroxyvitamin D [1,25(OH)₂D] levels and ESA hyporesponsiveness in patients with pre-dialysis CKD has not been fully clarified.

Methods

This retrospective cohort study included 376 adult patients with anemia and pre-dialysis CKD who received continuous erythropoietin receptor activator (CERA) therapy for at least three months. ESA hyporesponsiveness was assessed using the erythropoietin resistance index (ERI), calculated as the body weight–adjusted monthly CERA dose divided by the mean hemoglobin concentration during the first three months of treatment. Patients in the highest ERI tertile were classified as ESA hyporesponsive. Logistic regression analysis was performed to identify factors associated with ESA hyporesponsiveness, and linear regression analysis was used to evaluate variables related to ERI.

Results

Among 376 patients, 126 (33.5%) were classified as ESA hyporesponsive. Serum 1,25(OH)₂D levels were significantly lower in the ESA-hyporesponsive group than in the non-hyporesponsive group. In multivariable logistic regression analysis, serum 1,25(OH)₂D levels were independently associated with ESA hyporesponsiveness. Serum 1,25(OH)₂D was also independently and inversely associated with ERI in multivariable linear regression analysis. This association was consistent across predefined subgroups. Receiver operating characteristic curve analysis showed that serum 1,25(OH)₂D had acceptable discriminative performance for ESA hyporesponsiveness, with an optimal cutoff value of ≤ 14.6 pg/mL.

Conclusion

Lower serum 1,25(OH)₂D levels were independently associated with ESA hyporesponsiveness in patients with pre-dialysis CKD. These findings suggest that active vitamin D status may be a clinically relevant factor in ESA responsiveness.