尿素与肌酐比值对胃肠道出血源的诊断价值：肾功能的影响
Diagnostic value of the urea-to-creatinine ratio for gastrointestinal bleeding source: influence of renal function.
作者信息
Russ Philipp, Koppenhöfer Julian M, Bedenbender Simon, Tarawneh Thomas S, Denzer Ulrike W, Grgic Ivica, Rußwurm Martin, Haas Christian S
机构信息
Division of Nephrology, Centre for Internal Medicine, Marburg University, University Hospital Giessen and Marburg, Marburg, Germany.
Institute for Artificial Intelligence in Medicine, Marburg University, University Hospital Giessen and Marburg, Marburg, Germany.
出版信息
BMC Nephrol. 2025 Aug 18;26(1):464. doi: 10.1186/s12882-025-04382-y.
BACKGROUND
Gastrointestinal (GI) bleeding is frequent and clinically critical, especially in patients with renal dysfunction. Localization of the source is relevant for treatment and outcomes. The urea-to-creatinine ratio (UCR) has been proposed as a tool to differentiate between upper and lower GI bleeding. However, its diagnostic utility across varying degrees of renal impairment remains unclear.
METHODS
From January 2021 to October 2023, all patients with suspected GI bleeding who underwent endoscopy were retrospectively analyzed in a single center. Patients without confirmed bleeding were excluded. Patients were stratified by renal function: normal renal function, chronic kidney disease (CKD), acute kidney injury (AKI), and AKI with pre-existing CKD (acute-on-chronic). We assessed the discriminatory power of the UCR to distinguish upper from lower GI bleeding within each group.
RESULTS
A total of 849 patients (mean age 66.9 ± 18.2 years) were included. Approximately two-thirds of the patients ( = 544; 64.1%) were male. CKD was present in 321 (37.8%) and AKI in 354 (41.7%) patients; 199 (56.2%) of those with AKI had pre-existing CKD. Upper GI bleeding occurred more frequently in patients with AKI (75.1%) and CKD (72.9%) than in those with normal renal function ( < 0.0001 and = 0.0003, respectively); both groups also required transfusions more frequently ( < 0.0001 for both). UCR values were significantly higher in upper vs. lower GI bleeding in patients with normal renal function (67.5 vs. 42.5; < 0.0001), but this difference was reduced in CKD (49.3 vs. 41.0; = 0.0103) and not significant in AKI (53.1 vs. 47.7; = 0.09). The diagnostic performance of UCR was best in patients with normal renal function (AUROC 0.69) and markedly impaired in CKD (AUROC 0.56) and AKI (AUROC 0.54).
CONCLUSION
The diagnostic value of UCR to localize GI bleeding depends strongly on renal function. While the UCR may help to identify the bleeding site in patients with normal kidney function, impaired renal function hampers the reliability of the UCR, especially in patients with AKI. As renal dysfunction is common in patients with GI bleeding, kidney function must be taken into account when interpreting UCR values.
SUPPLEMENTARY INFORMATION
The online version contains supplementary material available at 10.1186/s12882-025-04382-y.
背景
胃肠道（GI）出血很常见且临床情况危急，尤其是在肾功能不全的患者中。出血源的定位对于治疗和预后至关重要。尿素与肌酐比值（UCR）已被提议作为区分上消化道和下消化道出血的一种工具。然而，其在不同程度肾功能损害中的诊断效用仍不清楚。
方法
对2021年1月至2023年10月在单一中心接受内镜检查的所有疑似胃肠道出血患者进行回顾性分析。排除未确诊出血的患者。根据肾功能将患者分层：肾功能正常、慢性肾脏病（CKD）、急性肾损伤（AKI）以及伴有既往CKD的AKI（急性慢性肾损伤）。我们评估了UCR在每组中区分上消化道和下消化道出血的鉴别能力。
结果
共纳入849例患者（平均年龄66.9±18.2岁）。约三分之二的患者（n = 544；64.1%）为男性。321例（37.8%）患者存在CKD，354例（41.7%）患者存在AKI；AKI患者中有199例（56.2%）有既往CKD。AKI患者（75.1%）和CKD患者（72.9%）上消化道出血的发生率高于肾功能正常的患者（分别为P < 0.0001和P = 0.0003）；这两组患者输血的频率也更高（两组均为P < 0.0001）。肾功能正常的患者上消化道出血时UCR值显著高于下消化道出血（67.5 vs. 42.5；P < 0.0001），但在CKD患者中这种差异减小（49.3 vs. 41.0；P = 0.0103），在AKI患者中不显著（53.1 vs. 47.7；P = 0.09）。UCR的诊断性能在肾功能正常的患者中最佳（曲线下面积[AUC] 0.69），在CKD患者中显著受损（AUC 0.56），在AKI患者中受损更明显（AUC 0.54）。
结论
UCR定位胃肠道出血的诊断价值很大程度上取决于肾功能。虽然UCR可能有助于识别肾功能正常患者的出血部位，但肾功能受损会妨碍UCR的可靠性，尤其是在AKI患者中。由于肾功能不全在胃肠道出血患者中很常见，在解释UCR值时必须考虑肾功能。
补充信息
在线版本包含可在10.1186/s12882 - 025 - 04382 - y获取的补充材料。
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