An equation to estimate 24-hour total urine protein excretion rate in patients who underwent urine protein testing
Abstract Background The urine protein-creatinine ratio (UPCR) in a spot first-morning urine sample is used to estimate 24-h urine proteinuria (24hUP) in patients who underwent urine protein testing. UPCR cannot be directly compared with 24-h proteinuria. Thus, an equation to estimate 24-h total prot...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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BMC
2022-01-01
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| Series: | BMC Nephrology |
| Subjects: | |
| Online Access: | https://doi.org/10.1186/s12882-022-02673-2 |
| _version_ | 1818306087128924160 |
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| author | Fan Yang Jing-Song Shi Si-Wen Gong Xiao-Dong Xu Wei-Bo Le |
| author_facet | Fan Yang Jing-Song Shi Si-Wen Gong Xiao-Dong Xu Wei-Bo Le |
| author_sort | Fan Yang |
| collection | DOAJ |
| description | Abstract Background The urine protein-creatinine ratio (UPCR) in a spot first-morning urine sample is used to estimate 24-h urine proteinuria (24hUP) in patients who underwent urine protein testing. UPCR cannot be directly compared with 24-h proteinuria. Thus, an equation to estimate 24-h total protein excretion rate, using age, gender, and the UPCR may improve its bias and accuracy in patients who underwent urine protein testing. Methods We simultaneously measured 24-h urine protein and the same day’s first-morning spot urine from patients with kidney disease. Generalized linear and no-linear models, using age, gender, and UPCR, were constructed to estimate for 24-h urine protein and the best model (NJ equation) was selected to estimated 24 hUP (e24hUP). Results A total of 5435 paired samples (including a training cohort of 3803 patients and a validation cohort of 1632 patients) were simultaneously measured for UPCR and 24-h urine protein. In the training cohort, the unadjusted UPCR obviously underestimated 24-h urine protein when UPCR ≤1.2 g/g (median bias − 0.17 g/24 h) and overestimated 24-h urine protein when UPCR > 1.2 g/g (median bias 0.53 g/24 h). In the validation cohort, the NJ equation performed better than the unadjusted UPCR, with lower root mean square error (0.81 vs. 1.02, P < 0.001), less bias (median difference between measured and estimated urine protein, − 0.008 vs. 0.12), improved precision (interquartile range of the differences, 0.34 vs. 0.50), and greater accuracy (percentage of estimated urine protein within 30% of measured urine protein, 53.4% vs. 32.2%). Bland-Altman plot indicated that the agreement of spot and daily estimates was less pronounced with 24 hUP > 2 g than lower values. Conclusions The NJ e24hUP equation is more accurate than unadjusted UPCR to estimate 24 hUP in patients with kidney disease and could be used for laboratory application. |
| first_indexed | 2024-12-13T06:36:54Z |
| format | Article |
| id | doaj.art-622a269ad6b44e1ca612b19f0020aee6 |
| institution | Directory Open Access Journal |
| issn | 1471-2369 |
| language | English |
| last_indexed | 2024-12-13T06:36:54Z |
| publishDate | 2022-01-01 |
| publisher | BMC |
| record_format | Article |
| series | BMC Nephrology |
| spelling | doaj.art-622a269ad6b44e1ca612b19f0020aee62022-12-21T23:56:29ZengBMCBMC Nephrology1471-23692022-01-012311810.1186/s12882-022-02673-2An equation to estimate 24-hour total urine protein excretion rate in patients who underwent urine protein testingFan Yang0Jing-Song Shi1Si-Wen Gong2Xiao-Dong Xu3Wei-Bo Le4National Clinical Research Center of Kidney Diseases, Jinling Hospital, Nanjing University School of MedicineNational Clinical Research Center of Kidney Diseases, Jinling Hospital, Nanjing University School of MedicineNational Clinical Research Center of Kidney Diseases, Jinling Hospital, the First School of Clinical Medicine, Southern Medical UniversityNational Clinical Research Center of Kidney Diseases, Jinling Hospital, Nanjing University School of MedicineNational Clinical Research Center of Kidney Diseases, Jinling Hospital, Nanjing University School of MedicineAbstract Background The urine protein-creatinine ratio (UPCR) in a spot first-morning urine sample is used to estimate 24-h urine proteinuria (24hUP) in patients who underwent urine protein testing. UPCR cannot be directly compared with 24-h proteinuria. Thus, an equation to estimate 24-h total protein excretion rate, using age, gender, and the UPCR may improve its bias and accuracy in patients who underwent urine protein testing. Methods We simultaneously measured 24-h urine protein and the same day’s first-morning spot urine from patients with kidney disease. Generalized linear and no-linear models, using age, gender, and UPCR, were constructed to estimate for 24-h urine protein and the best model (NJ equation) was selected to estimated 24 hUP (e24hUP). Results A total of 5435 paired samples (including a training cohort of 3803 patients and a validation cohort of 1632 patients) were simultaneously measured for UPCR and 24-h urine protein. In the training cohort, the unadjusted UPCR obviously underestimated 24-h urine protein when UPCR ≤1.2 g/g (median bias − 0.17 g/24 h) and overestimated 24-h urine protein when UPCR > 1.2 g/g (median bias 0.53 g/24 h). In the validation cohort, the NJ equation performed better than the unadjusted UPCR, with lower root mean square error (0.81 vs. 1.02, P < 0.001), less bias (median difference between measured and estimated urine protein, − 0.008 vs. 0.12), improved precision (interquartile range of the differences, 0.34 vs. 0.50), and greater accuracy (percentage of estimated urine protein within 30% of measured urine protein, 53.4% vs. 32.2%). Bland-Altman plot indicated that the agreement of spot and daily estimates was less pronounced with 24 hUP > 2 g than lower values. Conclusions The NJ e24hUP equation is more accurate than unadjusted UPCR to estimate 24 hUP in patients with kidney disease and could be used for laboratory application.https://doi.org/10.1186/s12882-022-02673-2Urine protein-creatinine ratioProteinuriaPrediction model |
| spellingShingle | Fan Yang Jing-Song Shi Si-Wen Gong Xiao-Dong Xu Wei-Bo Le An equation to estimate 24-hour total urine protein excretion rate in patients who underwent urine protein testing BMC Nephrology Urine protein-creatinine ratio Proteinuria Prediction model |
| title | An equation to estimate 24-hour total urine protein excretion rate in patients who underwent urine protein testing |
| title_full | An equation to estimate 24-hour total urine protein excretion rate in patients who underwent urine protein testing |
| title_fullStr | An equation to estimate 24-hour total urine protein excretion rate in patients who underwent urine protein testing |
| title_full_unstemmed | An equation to estimate 24-hour total urine protein excretion rate in patients who underwent urine protein testing |
| title_short | An equation to estimate 24-hour total urine protein excretion rate in patients who underwent urine protein testing |
| title_sort | equation to estimate 24 hour total urine protein excretion rate in patients who underwent urine protein testing |
| topic | Urine protein-creatinine ratio Proteinuria Prediction model |
| url | https://doi.org/10.1186/s12882-022-02673-2 |
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