Lee Mi Jung, Park Jung Tak, Park Kyoung Sook, Kwon Young Eun, Oh Hyung Jung, Yoo Tae-Hyun, Kim Yong-Lim, Kim Yon Su, Yang Chul Woo, Kim Nam-Ho, Kang Shin-Wook, Han Seung Hyeok
Department of Internal Medicine, CHA Bundang Medical Center, CHA University, Seongnamsi, Korea.
Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Korea.
Clin J Am Soc Nephrol. 2017 Mar 7;12(3):426-434. doi: 10.2215/CJN.05520516. Epub 2017 Feb 22.
Residual kidney function can be assessed by simply measuring urine volume, calculating GFR using 24-hour urine collection, or estimating GFR using the proposed equation (eGFR). We aimed to investigate the relative prognostic value of these residual kidney function parameters in patients on dialysis.
DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: Using the database from a nationwide prospective cohort study, we compared differential implications of the residual kidney function indices in 1946 patients on dialysis at 36 dialysis centers in Korea between August 1, 2008 and December 31, 2014. Residual GFR calculated using 24-hour urine collection was determined by an average of renal urea and creatinine clearance on the basis of 24-hour urine collection. eGFR-urea, creatinine and eGFR -microglobulin were calculated from the equations using serum urea and creatinine and -microglobulin, respectively. The primary outcome was all-cause death.
During a mean follow-up of 42 months, 385 (19.8%) patients died. In multivariable Cox analyses, residual urine volume (hazard ratio, 0.96 per 0.1-L/d higher volume; 95% confidence interval, 0.94 to 0.98) and GFR calculated using 24-hour urine collection (hazard ratio, 0.98; 95% confidence interval, 0.95 to 0.99) were independently associated with all-cause mortality. In 1640 patients who had eGFR -microglobulin data, eGFR -microglobulin (hazard ratio, 0.98; 95% confidence interval, 0.96 to 0.99) was also significantly associated with all-cause mortality as well as residual urine volume (hazard ratio, 0.96 per 0.1-L/d higher volume; 95% confidence interval, 0.94 to 0.98) and GFR calculated using 24-hour urine collection (hazard ratio, 0.97; 95% confidence interval, 0.95 to 0.99). When each residual kidney function index was added to the base model, only urine volume improved the predictability for all-cause mortality (net reclassification index =0.11, =0.01; integrated discrimination improvement =0.01, =0.01).
Higher residual urine volume was significantly associated with a lower risk of death and exhibited a stronger association with mortality than GFR calculated using 24-hour urine collection and eGFR-urea, creatinine. These results suggest that determining residual urine volume may be beneficial to predict patient survival in patients on dialysis.
残余肾功能可通过简单测量尿量、利用24小时尿液收集计算肾小球滤过率（GFR）或使用推荐公式估算GFR（eGFR）来评估。我们旨在研究这些残余肾功能参数在透析患者中的相对预后价值。
设计、地点、参与者与测量方法：利用一项全国性前瞻性队列研究的数据库，我们比较了2008年8月1日至2014年12月31日期间韩国36个透析中心1946例透析患者中残余肾功能指标的不同影响。通过24小时尿液收集计算的残余GFR由基于24小时尿液收集的肾尿素和肌酐清除率平均值确定。eGFR-尿素、肌酐和eGFR-微球蛋白分别根据使用血清尿素、肌酐和微球蛋白的公式计算得出。主要结局为全因死亡。
在平均42个月的随访期间，385例（19.8%）患者死亡。在多变量Cox分析中，残余尿量（风险比，每增加0.1L/d，风险比为0.96；95%置信区间，0.94至0.98）和通过24小时尿液收集计算的GFR（风险比，0.98；95%置信区间，0.95至0.99）与全因死亡率独立相关。在1640例有eGFR-微球蛋白数据的患者中，eGFR-微球蛋白（风险比，0.98；95%置信区间，0.96至0.99）也与全因死亡率显著相关，以及残余尿量（风险比，每增加0.1L/d，风险比为0.96；95%置信区间，0.94至0.98）和通过24小时尿液收集计算的GFR（风险比，0.97；95%置信区间，0.95至0.99）。当将每个残余肾功能指标添加到基础模型中时，只有尿量改善了全因死亡率的预测能力（净重新分类指数=0.11，P=0.01；综合判别改善=0.01，P=0.01）。
较高的残余尿量与较低的死亡风险显著相关，并且与死亡率的关联比通过24小时尿液收集计算的GFR以及eGFR-尿素、肌酐更强。这些结果表明，确定残余尿量可能有助于预测透析患者的生存情况。
