Division of Nephrology, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung Medical University, 100 Tzyou First Road, San-Ming District, Kaohsiung, 807, Taiwan.
Graduate Institute of Clinical Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan.
Sci Rep. 2021 Apr 16;11(1):8343. doi: 10.1038/s41598-021-87401-w.
Low transferrin saturation (TSAT), calculated by serum iron divided by total iron-binding capacity (TIBC), indicates iron deficiency. Because malnutrition and inflammation are associated with low TIBC in chronic kidney disease (CKD), TSAT might not reflect iron status or risk for anemia. We examined whether low serum iron was a risk factor for anemia in CKD patients with normal TSAT. Thus we compare the risk for anemia in 2500 CKD stage 1-4 patients divided by TSAT (cutoff: 20%) and serum iron (cutoff: 70 μg/dL in men, 60 μg/dL in women). Our results confirmed low TIBC (< 200 μg/dL) was associated with hypoalbuminemia and high C-reactive protein. In fully-adjusted logistic regression, both "normal TSAT low iron" and "low TSAT low iron" groups were associated with baseline anemia (hemoglobin < 11 g/dL) (odds ratios (OR) 1.56; 95% confidence interval (CI) 1.13-2.16 and OR 2.36; 95% CI 1.76-3.18, respectively) compared with the reference group (normal TSAT normal iron). Sensitivity tests with different cutoffs for TSAT and iron also showed similar results. In patients without anemia, both groups were associated with anemia after 1 year (OR 1.69; 95% CI 1.00-2.83 and OR 1.94; 95% CI 1.11-3.40, respectively). In conclusion, CKD stage 1-4 patients with normal TSAT but low serum iron are still at risk for anemia.
转铁蛋白饱和度（TSAT）较低（通过血清铁除以总铁结合力（TIBC）计算得出）提示缺铁。由于营养不良和炎症与慢性肾脏病（CKD）中的 TIBC 降低有关，因此 TSAT 可能无法反映铁状态或贫血风险。我们研究了在 TSAT 正常（分界值：20%）和血清铁正常（男性 70μg/dL，女性 60μg/dL）的 CKD 患者中，血清铁较低是否为贫血的危险因素。因此，我们比较了 2500 名 CKD 1-4 期患者按 TSAT（分界值：20%）和血清铁（分界值：男性 70μg/dL，女性 60μg/dL）划分的贫血风险。我们的研究结果证实，TIBC 较低（<200μg/dL）与低白蛋白血症和高 C 反应蛋白相关。在完全校正的逻辑回归中，“TSAT 正常铁不足”和“TSAT 低铁不足”组与基线贫血（血红蛋白<11g/dL）相关（比值比（OR）分别为 1.56（95%置信区间（CI）为 1.13-2.16 和 2.36（95%CI 为 1.76-3.18）），与参考组（TSAT 和铁均正常）相比。TSAT 和铁的不同分界值的敏感性试验也显示出相似的结果。在无贫血的患者中，两组在 1 年后均与贫血相关（OR 分别为 1.69（95%CI 为 1.00-2.83 和 1.94（95%CI 为 1.11-3.40））。总之，TSAT 正常但血清铁较低的 CKD 1-4 期患者仍有发生贫血的风险。
