INSERM, CESP Centrefor Research inEpidemiology and Population Health, U1018, Epidemiology of Diabetes, Obesity, and Kidney DiseasesTeam, Villejuif, France.
Clin J Am Soc Nephrol. 2012 Jan;7(1):35-42. doi: 10.2215/CJN.04690511. Epub 2011 Nov 17.
Anemia in patients with CKD is highly related to impaired erythropoietin (EPO) response, the timing and determinants of which remain unknown.
DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: This study measured EPO levels and studied their relation to GFR measured by 51Cr-EDTA renal clearance (mGFR) in 336 all-stage CKD patients not receiving any erythropoiesis-stimulating agent.
In patients with anemia defined by World Health Organization criteria (hemoglobin [Hb] <13 g/dl in men and 12 g/dl in women), EPO response to Hb level varied by mGFR level. EPO and Hb levels were negatively correlated (r=-0.22, P=0.04) when mGFR was >30 ml/min per 1.73 m(2), whereas they were not correlated when mGFR was <30 (r=0.09, P=0.3; P for interaction=0.01). In patients with anemia, the ratio of observed EPO to the level predicted by the equation for their Hb level decreased from 0.72 (interquartile range, 0.57-0.95) for mGFR ≥60 ml/min per 1.73 m(2) to 0.36 (interquartile range, 0.16-0.69) for mGFR <15. Obesity, diabetes with nephropathy other than diabetic glomerulopathy, absolute iron deficiency, and high C-reactive protein concentrations were associated with increased EPO levels, independent of Hb and mGFR.
Anemia in CKD is marked by an early relative EPO deficiency, but several factors besides Hb may persistently stimulate EPO synthesis. Although EPO deficiency is likely the main determinant of anemia in patients with advanced CKD, the presence of anemia in those with mGFR >30 ml/min per 1.73 m(2) calls for other explanatory factors.
慢性肾脏病（CKD）患者贫血与促红细胞生成素（EPO）反应受损高度相关，但其发生时间和决定因素尚不清楚。
设计、设置、参与者和测量方法：本研究测量了 336 例未接受任何促红细胞生成刺激剂治疗的各期 CKD 患者的 EPO 水平，并研究了其与 51Cr-EDTA 肾清除率（mGFR）测定的肾小球滤过率（GFR）之间的关系。
在根据世界卫生组织标准（男性血红蛋白[Hb]＜13g/dl，女性 Hb＜12g/dl）定义贫血的患者中，EPO 对 Hb 水平的反应因 mGFR 水平而异。当 mGFR＞30ml/min/1.73m2 时，EPO 与 Hb 水平呈负相关（r=-0.22，P=0.04），而当 mGFR＜30ml/min/1.73m2 时，两者无相关性（r=0.09，P=0.3；P 交互=0.01）。在贫血患者中，观察到的 EPO 与根据其 Hb 水平方程预测的 EPO 水平之比从 mGFR≥60ml/min/1.73m2 时的 0.72（四分位距，0.57-0.95）降至 mGFR＜15ml/min/1.73m2 时的 0.36（四分位距，0.16-0.69）。肥胖、非糖尿病肾小球病变的糖尿病肾病、绝对铁缺乏和高 C 反应蛋白浓度与 EPO 水平升高相关，与 Hb 和 mGFR 无关。
CKD 患者贫血表现为早期相对 EPO 缺乏，但除 Hb 外，还有多种因素可能持续刺激 EPO 合成。尽管 EPO 缺乏可能是晚期 CKD 患者贫血的主要决定因素，但 mGFR＞30ml/min/1.73m2 的患者存在贫血需要寻找其他解释因素。
