随机尿钾与尿肌酐比值在判断肾性失钾中的应用价值研究

Application Value of Random Urine Potassium-to-Creatinine Ratio in Diagnosing Renal Potassium Loss

目的分析随机尿钾/尿肌酐(rUK/Ucr)在判断肾性失钾中的应用价值。方法纳入2017–2021年诊断为低钾血症患者〔包括肾性失钾(373例)、非肾性失钾(83例)〕、血钾正常(358例)的住院患者。收集临床资料,分析rUK/Ucr与24 h尿钾(24 hUK)的相关性;针对低钾血症患者绘制受试者工作特征(ROC)曲线,分析rUK/Ucr判断肾性失钾的价值。结果血钾在血钾正常组、肾性失钾组、非肾性失钾组依次降低(P<0.01)。肾性失钾组24 hUK、rUK/Ucr大于非肾性失钾及血钾正常组(P<0.01)。rUK/Ucr与24 hUK呈低到中度相关。24 hUK、rUK/Ucr判断肾性失钾的曲线下面积(AUC)分别为0.73、0.71,rUK/Ucr判断肾性失钾的最佳切点为3.4时,灵敏度为67.59%,特异度为67.53%。结论rUK/Ucr与24 hUK的相关性一般,rUK/Ucr预测肾性失钾的价值与24 hUK相当。在无法获取24 h尿液标本时,可推荐使用rUK/Ucr替代24 hUK来初步判断是否存在肾性失钾,其最佳诊断切点为3.4。

Objective To analyze the value of applying random urine potassium-to-creatinine ratio(rUK/Ucr)in diagnosing renal potassium loss.Methods patients diagnosed with hypokalemia,including 373 cases of renal potassium loss,83 cases of non-renal potassium loss,and 358 cases of normal serum potassium,between 2017 and 2021 were enrolled.The clinical data of the patients were collected and the correlation between rUK/Ucr and 24-hour urine potassium(24 hUK)in the three groups was analyzed.The receiver operating characteristic(ROC)curve was used to analyze the value of applying rUK/Ucr in diagnosing renal potassium loss.Results Serum potassium decreased in the normal serum potassium group,the renal potassium loss group,and the non-renal renal potassium loss group(P<0.01).The 24 hUK and the rUK/Ucr of the renal potassium loss group were higher than those of the non-renal potassium loss group and normal serum potassium group(P<0.01).rUK/Ucr showed low to moderate correlation with 24 hUK.The AUC of 24 hUK and rUK/Ucr for determining renal potassium loss were 0.73 and 0.71,respectively.When the optimal cutoff point of rUK/Ucr for determining renal potassium loss was 3.4,the sensitivity was 67.6%and the specificity was 67.5%.Conclusion rUK/Ucr shows a moderate correlation with 24 hUK and its accuracy in determining renal potassium loss is comparable to that of 24 hUK.When 24-hour urine samples cannot be obtained,it is recommended that rUK/Ucr be used instead of 24 hUK to determine whether renal potassium loss exists,with the optimal cutoff point for diagnosis being 3.4.