Correlation study between spot urine protein-to-creatinine ratio and 24-hour urine protein measurement in 174 patients for proteinuria assessment

SummaryBackground/PurposeAccording to the US National Kidney Foundation K/DOQI Guidelines in 2000, under most circumstances, spot urine samples should be used to detect and monitor proteinuria in children and adults and timed collection is often unnecessary. However, its use is still not widely implemented in Hong Kong. We aimed to assess the correlation of spot urine protein-to-creatinine (Pr/Cr) ratio to 24-hour urine protein excretion in our local setting.MethodsThis was a prospective study set in regional hospitals in Hong Kong. A total of 174 patients were recruited from 2007 to 2008. Spot urine Pr/Cr ratio and 24-hour urine protein measurements were determined. Linear regression model was used to fit and test the relationship between 24-hour urine protein excretion and the spot urine Pr/Cr ratio.ResultsSpot urine Pr/Cr ratio correlated well with 24-hour urine protein excretion (r = 0.95, p < 0.0001).ConclusionSpot urine Pr/Cr ratio is a convenient, user-friendly and reliable method to replace 24-hour urine protein measurement for the assessment of proteinuria.背景根據 2000 年美國國家腎臟基金會的 K/DOQI 指引，對於偵測及監察成人及兒童的蛋白尿，在大多數情況下採用隨機單次尿液檢體即可，毋須講究尿液收集的時間。然而，此措施在香港並未被廣泛應用。本研究之目的，是在香港的區域醫院內，測量病人隨機單次尿液之蛋白-肌酸酐 (Pr/Cr) 比例、及 24 小時之尿蛋白排泄量，並調查兩者的相關性。方法研究採取前瞻性的方式，在 2007 至 2008 年間共納入 174 位病人，分別測量隨機單次尿液 Pr/Cr 比例及 24 小時尿蛋白排泄量，並以線性回歸法進行數據的分析。結果結果顯示，隨機單次尿液 Pr/Cr 比例與 24 小時尿蛋白排泄量呈現顯著的相關性 (r = 0.95、p < 0.0001)。結論在蛋白尿的評估上，作為一個簡便而可靠的指標，隨機單次尿液 Pr/Cr 比例理應可取代 24 小時尿蛋白排泄量。