Hildegard Stancu Simona, Stanciu Ana, Lipan Mariana, Capusa Cristina
"Carol Davila" University of Medicine and Pharmacy, Nephrology Dept., Bucharest, Romania.
"Dr. Carol Davila" Teaching Hospital of Nephrology, Bucharest, Romania.
J Med Life. 2018 Oct-Dec;11(4):293-298. doi: 10.25122/jml-2019-0002.
Anemia, a common feature in chronic kidney disease (CKD), has multiple contributors to its pathogenesis. Besides the well recognized erythropoietin and iron deficiencies, hydration status might be involved. To assess the prevalence and correlations of anemia, iron deficiency and overhydration in patients with stage 2 to 5 CKD. This cross-sectional study enrolled 125 erythropoietin and iron therapy naïve non-dialysis CKD patients, without a identifiable cause of anemia. Parameters of hematological, iron, inflammatory and nutritional status were measured. The overhydration parameter (OH) assessed by bioimpedance spectroscopy was used to characterize hydration status. The prevalence of decreased hemoglobin (Hb) <110g/L increased along CKD stages from 0% to 40% (=0.008). Fluid overload (OH >1L) and lower serum albumin (<40g/L) were more common in stage 5 versus stage 3 CKD (53% vs. 10%, <0.001, and 27% vs. 3%, =0.02, respectively), suggesting a potential dilutional reduction in serum proteins. Conversely, decreased iron stores (ferritin <100mcg/L) and iron availability (transferrin saturation, TSAT<0.20) were similarly prevalent irrespective of kidney function decline. Hemoglobin was positively correlated with estimated glomerular filtration rate (eGFR), serum albumin, and transferrin saturation, but inversely with OH. However, in a model of multiple linear regression which explained 32% of hemoglobin variation, only eGFR and overhydration remained the independent predictors of anemia. As fluid overload is a common denominator for hemoglobin and TSAT levels, and is closely related to the declining kidney function, it should be considered in the management of renal anemia, at least in advanced CKD.
贫血是慢性肾脏病（CKD）的常见特征，其发病机制有多种因素。除了众所周知的促红细胞生成素和铁缺乏外，水合状态可能也与之有关。为评估2至5期CKD患者贫血、缺铁和水合过度的患病率及相关性。这项横断面研究纳入了125例未接受促红细胞生成素和铁治疗的非透析CKD患者，且无明确的贫血病因。测量了血液学、铁、炎症和营养状态参数。采用生物电阻抗光谱法评估的水合过度参数（OH）来表征水合状态。血红蛋白（Hb）<110g/L的患病率随CKD分期增加，从0%增至40%（P=0.008）。与3期CKD相比，5期CKD患者中液体超负荷（OH>1L）和血清白蛋白降低（<40g/L）更为常见（分别为53%对10%，P<0.001，以及27%对3%，P=0.02），提示血清蛋白可能存在稀释性降低。相反，无论肾功能下降情况如何，铁储备降低（铁蛋白<100mcg/L）和铁利用率（转铁蛋白饱和度，TSAT<0.20）的患病率相似。血红蛋白与估计肾小球滤过率（eGFR）、血清白蛋白和转铁蛋白饱和度呈正相关，但与OH呈负相关。然而，在一个解释了32%血红蛋白变异的多元线性回归模型中，只有eGFR和水合过度仍是贫血的独立预测因素。由于液体超负荷是血红蛋白和TSAT水平的共同因素，且与肾功能下降密切相关，因此在肾性贫血的管理中应予以考虑，至少在晚期CKD中如此。
