Abstract: FR-PO524

Serum 1,25 Dihydroxyvitamin D Is Independently Associated with Erythropoietin Deficiency and Endogenous Erythropoietin Resistance in Patients with CKD

Session Information

Category: Chronic Kidney Disease (Non-Dialysis)

  • 304 CKD: Epidemiology, Outcomes - Non-Cardiovascular

Authors

  • Kim, Il Young, Pusan National University Yangsan Hospital, Yangsan, Korea (the Republic of)
  • Kwak, Ihm Soo, Pusan National University Hospital, Busan, Korea (the Republic of)
  • Park, In seong, Pusan National University Hospital, Busan, Korea (the Republic of)
  • Kim, Min Jeong, Pusan National University Yangsan Hospital, Yangsan, Korea (the Republic of)
  • Han, Miyeun, Pusan National University Hospital, Busan, Korea (the Republic of)
  • Rhee, Harin, Pusan National University Hospital, Busan, Korea (the Republic of)
  • Song, Sang Heon, Pusan National University Hospital, Busan, Korea (the Republic of)
  • Seong, Eun Young, Pusan National University Hospital, Busan, Korea (the Republic of)
  • Lee, Dong Won, Pusan National University Yangsan Hospital, Yangsan, Korea (the Republic of)
  • Lee, Soo Bong, Pusan National University Yangsan Hospital, Yangsan, Korea (the Republic of)
Background

Erythropoietin (EPO) deficiency and resistance to endogenous EPO is an important pathophysiological feature in anemia of chronic kidney disease (CKD). 1,25 dihydroxyvitamin D [1,25(OH)2D] deficiency is known to contribute to anemia of CKD. We aimed to investigate the associations between serum 1,25(OH)2D, EPO deficiency and endogenous EPO resistance in patients with CKD.

Methods

This study included 409 patients with CKD [glomerular filtration rate (GFR) < 60 ml/min/1.73m2] who were not on dialysis therapy. Patients on exogenous EPO therapy and patients with iron deficiencies were excluded. Endogenous EPO resistance was assessed by calculating the ratio of endogenous EPO to hemoglobin (Hb) (endogenous EPO/Hb ratio). The associations of Hb level, endogenous EPO level and the endogenous EPO/Hb ratio with clinical and laboratory variables were investigated by univariate and multivariate analyses.

Results

In univariate analysis, serum 1,25(OH)2D level was correlated with the Hb level (r = 0.705, P < 0.001), endogenous EPO level (r = 0.254, P < 0.001) and the endogenous EPO/Hb ratio (r = -0.132, P = 0.007). Multiple regression analysis revealed that the serum 1,25(OH)2D level remained significantly associated with the Hb level (β = 0.530, P < 0.001), endogenous EPO level (β = 0.127, P = 0.025) and the endogenous EPO/Hb ratio (β = -0.106, P = 0.035), even after adjusting for other confounding factors, including the levels of parathyroid hormone and the inflammatory marker C-reactive protein.

Conclusion

The serum 1,25(OH)2D level exhibited significant associations with anemia, EPO deficiency and endogenous EPO resistance in CKD patients. These associations were independent of secondary hyperparathyroidism and inflammation status.