Department of Nephrology, Matsunami General Hospital, Gifu, Japan.
Department of Internal Medicine, Matsunami General Hospital, Gifu, Japan.
PLoS One. 2023 Mar 10;18(3):e0282864. doi: 10.1371/journal.pone.0282864. eCollection 2023.
The bioelectrical impedance analysis-measured ratio of extracellular water (ECW) to intracellular water (ICW) reflects fluid volume and malnutrition. It may be an indicator of protein-energy wasting and muscle wasting in hemodialysis patients. We examined the association between the ECW/ICW ratio and simplified creatinine index, which is a new surrogate marker of protein-energy wasting and muscle wasting, and whether their combination can accurately predict mortality. A total of 224 patients undergoing hemodialysis for more than 6 months and having undergone bioelectrical impedance analysis for the assessment of body composition were included. Patients were divided into two groups based on the cut-off values of the ECW/ICW ratio (0.57) and simplified creatinine index (20.4 mg/kg/day) for maximumly predicting mortality. Thereafter, they were cross-classified into four groups with each cut-off point. The ECW/ICW ratio was independently associated with the simplified creatinine index (β = -0.164; P = 0.042). During a follow-up of 3.5 years (2.0-6.0 years), 77 patients died. A higher ECW/ICW ratio (adjusted hazard ratio, 3.66, 95% confidence interval 1.99-6.72, P <0.0001) and lower simplified creatinine index (adjusted hazard ratio, 2.25, 95% confidence interval 1.34-3.79, P = 0.0021) were independently associated with an increased risk of all-cause mortality. The adjusted hazard ratio for the higher ECW/ICW ratio and lower simplified creatinine index group vs. the lower ECW/ICW ratio and higher simplified creatinine index group was 12.22 (95% confidence interval 3.68-40.57, p <0.0001). Furthermore, the addition of the ECW/ICW ratio and simplified creatinine index to the baseline risk model significantly improved the C-index from 0.831 to 0.864 (p = 0.045). In conclusion, the ECW/ICW ratio may be a surrogate marker of muscle wasting. Moreover, combining the ECW/ICW ratio and simplified creatinine index may improve the accuracy of predicting all-cause mortality and help stratify the mortality risk of hemodialysis patients.
细胞外液（ECW）与细胞内液（ICW）的生物电阻抗分析比反映了液体容量和营养不良。它可能是血液透析患者蛋白质能量消耗和肌肉消耗的指标。我们检查了 ECW/ICW 比值与简化肌酐指数（一种新的蛋白质能量消耗和肌肉消耗的替代标志物）之间的相关性，以及它们的组合是否可以准确预测死亡率。共纳入 224 名接受血液透析治疗超过 6 个月并进行生物电阻抗分析评估身体成分的患者。根据 ECW/ICW 比值（0.57）和简化肌酐指数（20.4mg/kg/天）的截断值将患者分为两组，以最大预测死亡率。此后，他们根据每个截断点交叉分类为四组。ECW/ICW 比值与简化肌酐指数独立相关（β=-0.164；P=0.042）。在 3.5 年（2.0-6.0 年）的随访中，77 名患者死亡。较高的 ECW/ICW 比值（调整后的危险比，3.66，95%置信区间 1.99-6.72，P<0.0001）和较低的简化肌酐指数（调整后的危险比，2.25，95%置信区间 1.34-3.79，P=0.0021）与全因死亡率增加独立相关。较高的 ECW/ICW 比值和较低的简化肌酐指数组与较低的 ECW/ICW 比值和较高的简化肌酐指数组相比，调整后的危险比为 12.22（95%置信区间 3.68-40.57，P<0.0001）。此外，将 ECW/ICW 比值和简化肌酐指数添加到基线风险模型中，显著提高了 C 指数从 0.831 到 0.864（P=0.045）。总之，ECW/ICW 比值可能是肌肉消耗的替代标志物。此外，结合 ECW/ICW 比值和简化肌酐指数可能会提高预测全因死亡率的准确性，并有助于分层血液透析患者的死亡风险。
