Demirci C, Aşcı G, Demirci M S, Özkahya M, Töz H, Duman S, Sipahi S, Erten S, Tanrısev M, Ok E
FMC Turkey Clinics, Izmir, Turkey.
Division of Nephrology, Ege University School of Medicine, Izmir, Turkey.
Int Urol Nephrol. 2016 Jul;48(7):1155-62. doi: 10.1007/s11255-016-1292-1. Epub 2016 Apr 19.
Impedance ratio (Imp-R) obtained by multifrequency bioimpedance analysis (BIA) has been shown to be associated with volume and nutrition status. In this prospective study, the predictive role of Imp-R for mortality in hemodialysis (HD) patients was investigated.
Multifrequency (5-50-100-200 kHz) BIA was applied to 493 prevalent HD patients in March-April 2006. Imp-R was defined as the ratio of 200-5 kHz impedance values. Demographical, clinical and laboratory data at the time of the analysis were recorded. All-cause and cardiovascular (CV) mortality were assessed during 3 years of follow-up.
Mean age was 57.7 ± 13.9 years, HD duration 52.1 ± 42.6 months and prevalence of diabetes 21.7 %. Imp-R was negatively correlated with nutritional markers including albumin, creatinine and hemoglobin levels. In addition, there was a positive correlation between Imp-R and age, ratio of extracellular water to total body water and high-sensitive C-reactive protein. Over a mean follow-up period of 27.9 ± 11.1 months, 93 deaths (52 from CV reasons) were observed. In the multivariate analysis, Imp-R was significantly associated with all-cause and CV mortality after adjustments [HR 1.13, 95 % CI (1.04-1.23); p = 0.004 and HR 1.15, 95 % CI (1.03-1.27); p = 0.01, respectively]. The risk of all-cause mortality was 3.4 times higher in the fourth quartile of Imp-R (>83.5 %) compared to the first Imp-R quartile (<78.8 %) as reference. Cutoff value of Imp-R for all-cause mortality was 82.0 % with a sensitivity of 65.5 % and specificity of 64 %.
Impedance ratio measured by multifrequency in standardized conditions BIA is an independent and powerful predictor of both all-cause and CV mortality in hemodialysis patients.
多频生物电阻抗分析（BIA）获得的阻抗比（Imp-R）已被证明与容量和营养状况相关。在这项前瞻性研究中，研究了Imp-R对血液透析（HD）患者死亡率的预测作用。
2006年3月至4月，对493例HD患者进行了多频（5-50-100-200kHz）BIA检测。Imp-R定义为200-5kHz阻抗值的比值。记录分析时的人口统计学、临床和实验室数据。在3年的随访期间评估全因死亡率和心血管（CV）死亡率。
平均年龄为57.7±13.9岁，HD病程为52.1±42.6个月，糖尿病患病率为21.7%。Imp-R与包括白蛋白、肌酐和血红蛋白水平在内的营养指标呈负相关。此外，Imp-R与年龄、细胞外水与总体水的比值以及高敏C反应蛋白呈正相关。在平均随访期27.9±11.1个月内，观察到93例死亡（52例死于心血管原因）。在多变量分析中，调整后Imp-R与全因死亡率和CV死亡率显著相关[风险比（HR）1.13，95%置信区间（CI）（1.04-1.23）；p=0.004，HR 1.15，95%CI（1.03-1.27）；p=0.01]。与以第一四分位数Imp-R（<78.8%）为参考相比，Imp-R第四四分位数（>83.5%）的全因死亡风险高3.4倍。全因死亡率的Imp-R临界值为82.0%，敏感性为65.5%，特异性为64%。
在标准化条件下通过多频BIA测量的阻抗比是血液透析患者全因死亡率和CV死亡率的独立且有力的预测指标。
