Kim Il Young, Kim June Hyun, Kim Min Jeong, Lee Dong Won, Hwang Cheol Gu, Han Miyeun, Rhee Harin, Song Sang Heon, Seong Eun Young, Lee Soo Bong
Department of Internal Medicine, Pusan National University School of Medicine, Yangsan, South Korea.
Research Institute for Convergence of Biomedical Science and Technology, Pusan National University Yangsan Hospital, Yangsan, South Korea.
Int Urol Nephrol. 2018 Dec;50(12):2255-2260. doi: 10.1007/s11255-018-1967-x. Epub 2018 Aug 22.
Erythropoietin (EPO) deficiency and resistance to endogenous EPO is an important pathophysiological feature in anemia of chronic kidney disease (CKD). Low 1,25 dihydroxyvitamin D [1,25(OH)D] level is known to contribute to anemia of CKD. We aimed to investigate the associations between serum 1,25(OH)D and anemia, EPO deficiency, and endogenous EPO resistance in patients with CKD.
This study included 409 patients with CKD [glomerular filtration rate (GFR) < 60 ml/min/1.73 m] 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.
In univariate analysis, serum 1,25(OH)D level was correlated with the Hb level, endogenous EPO level, and the endogenous EPO/Hb ratio. Multiple regression analysis revealed that the serum 1,25(OH)D level remained significantly associated with the Hb level (β = 0.532, P < 0.001), endogenous EPO level (β = 0.149, P = 0.010), and the endogenous EPO/Hb ratio (β = - 0.187, P = 0.002), even after adjusting for other confounding factors, including the levels of parathyroid hormone and the inflammatory marker C-reactive protein.
The serum 1,25(OH)D 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.
促红细胞生成素（EPO）缺乏及对内源性EPO抵抗是慢性肾脏病（CKD）贫血的重要病理生理特征。已知低水平的1,25-二羟维生素D[1,25(OH)D]会导致CKD贫血。我们旨在研究CKD患者血清1,25(OH)D与贫血、EPO缺乏及内源性EPO抵抗之间的关联。
本研究纳入409例未接受透析治疗的CKD患者[肾小球滤过率（GFR）<60 ml/min/1.73 m²]。排除接受外源性EPO治疗的患者及缺铁患者。通过计算内源性EPO与血红蛋白（Hb）的比值（内源性EPO/Hb比值）评估内源性EPO抵抗。通过单因素和多因素分析研究Hb水平、内源性EPO水平及内源性EPO/Hb比值与临床和实验室变量之间的关联。
单因素分析中，血清1,25(OH)D水平与Hb水平、内源性EPO水平及内源性EPO/Hb比值相关。多因素回归分析显示，即使在调整了包括甲状旁腺激素水平和炎症标志物C反应蛋白等其他混杂因素后，血清1,25(OH)D水平仍与Hb水平（β=0.532，P<0.001）、内源性EPO水平（β=0.149，P=0.010）及内源性EPO/Hb比值（β=-0.187，P=0.002）显著相关。
CKD患者血清1,25(OH)D水平与贫血、EPO缺乏及内源性EPO抵抗显著相关。这些关联独立于继发性甲状旁腺功能亢进和炎症状态。
