Deng Xinwei, Gao Bixia, Wang Fang, Zhao Ming-Hui, Wang Jinwei, Zhang Luxia
Renal Division, Department of Medicine, Peking University First Hospital, Beijing, China.
Institute of Nephrology, Peking University, Beijing, China.
Front Med (Lausanne). 2022 Jun 9;9:877220. doi: 10.3389/fmed.2022.877220. eCollection 2022.
Chronic kidney disease (CKD) is a global public health issue. Red blood cell distribution width (RDW) is a recently recognized potential inflammatory marker, which mirrors the variability in erythrocyte volume. Studies indicate that elevated RDW is associated with increased risk of mortality in CKD patients, while evidence regarding the impact of RDW on kidney outcome is limited.
Altogether 523 patients with CKD stage 1-4 from a single center were enrolled. We identified the cutoff point for RDW level using maximally selected log-rank statistics. The time-averaged estimated glomerular filtration rate (eGFR) slope was determined using linear mixed effects models. Rapid CKD progression was defined by an eGFR decline >5 ml/min/1.73 m/year. The composite endpoints were defined as doubling of serum creatinine, a 30% decline in initial eGFR or incidence of eGFR < 15 ml/min/1.73 m, whichever occurred first. Multivariable logistic regression or Cox proportional hazards regression was performed, as appropriate.
During a median follow-up of 26 [interquartile range (IQR): 12, 36] months, 65 (12.43%) patients suffered a rapid CKD progression and 172 (32.89%) composite kidney events occurred at a rate of 32.3/100 patient-years in the high RDW group, compared with 14.7/100 patient-years of the remainder. The annual eGFR change was clearly steeper in high RDW group {-3.48 [95% confidence interval (CI): -4.84, -2.12] ml/min/1.73 m/year vs. -1.86 [95% CI: -2.27, -1.45] ml/min/1.73 m/year among those with RDW of >14.5% and ≤14.5%, respectively, for between-group difference <0.05}. So was the risk of rapid renal function loss (odds ratio = 6.79, 95% CI: 3.08-14.97) and composite kidney outcomes (hazards ratio = 1.51, 95% CI: 1.02-2.23). The significant association remained consistent in the sensitivity analysis.
Increased RDW value is independently associated with accelerated CKD deterioration. Findings of this study suggest RDW be a potential indicator for risk of CKD progression.
慢性肾脏病（CKD）是一个全球性的公共卫生问题。红细胞分布宽度（RDW）是一种最近被认可的潜在炎症标志物，它反映了红细胞体积的变异性。研究表明，CKD患者中RDW升高与死亡风险增加相关，而关于RDW对肾脏结局影响的证据有限。
共纳入来自单一中心的523例1-4期CKD患者。我们使用最大选择对数秩统计量确定RDW水平的截断点。使用线性混合效应模型确定时间平均估计肾小球滤过率（eGFR）斜率。快速CKD进展定义为eGFR下降>5 ml/min/1.73 m²/年。复合终点定义为血清肌酐翻倍、初始eGFR下降30%或eGFR<15 ml/min/1.73 m²的发生率，以先出现者为准。酌情进行多变量逻辑回归或Cox比例风险回归。
在中位随访26[四分位间距（IQR）：12，36]个月期间，高RDW组有65例（12.43%）患者出现快速CKD进展，172例（32.89%）发生复合肾脏事件，发生率为32.3/100患者年，而其余组为14.7/100患者年。高RDW组的年度eGFR变化明显更陡{-3.48[95%置信区间（CI）：-4.84，-2.12]ml/min/1.73 m²/年，而RDW>14.5%和≤14.5%的患者分别为-1.86[95%CI：-2.27，-1.45]ml/min/1.73 m²/年，组间差异<0.05}。快速肾功能丧失风险（比值比=6.79，95%CI：3.08-14.97）和复合肾脏结局（风险比=1.51，95%CI：1.02-2.23）也是如此。敏感性分析中显著关联仍然一致。
RDW值升高与CKD加速恶化独立相关。本研究结果表明RDW是CKD进展风险的潜在指标。
