Masahiro Naruse1, Masashi Mukoyama2, Jun Morinaga3,4, Masanobu Miyazaki5, Kunitoshi Iseki6, Kunihiro Yamagata7. 1. Medical Corporation Gyokuwakai, Tamana Dai-Ichi Clinic, 79-1 Tsuiji, Tamana, Kumamoto, 865-0065, Japan. naruse@gyokuwakai.or.jp. 2. Department of Nephrology, Kumamoto University Graduate School of Medical Sciences, 1-1-1 Honjo, Chuo-ku, Kumamoto, 860-8556, Japan. mmuko@kumamoto-u.ac.jp. 3. Department of Nephrology, Kumamoto University Graduate School of Medical Sciences, 1-1-1 Honjo, Chuo-ku, Kumamoto, 860-8556, Japan. 4. Department of Clinical Investigation, Kumamoto University Hospital, Kumamoto, Japan. 5. Medical Corporation, Miyazaki Internal Medicine, Nagasaki, Japan. 6. Clinical Research Support Center, Tomishiro Central Hospital, Okinawa, Japan. 7. Department of Nephrology, Faculty of Medicine, University of Tsukuba, Ibaraki, Japan.
Abstract
BACKGROUND: The dipstick urinalysis for proteinuria has been used for chronic kidney disease (CKD) screening at community-based health checkups; however, it has major drawbacks in that the result is only semi-quantitative and is influenced by urine concentration. METHODS: We conducted urine protein/creatinine ratio (UPCR) measurements of 590 participants who showed a result of more than trace proteinuria on a dipstick analysis and evaluated the usefulness of UPCR measurements in community-based health checkups. RESULTS: The UPCR values increased in accordance with the severity of the dipstick test findings, but statistical significance was only obtained between (±) and (1+), between (±) and (2+), and between (±) and (3+) groups. When the participants with (±) proteinuria were subjected to CGA classification (a classification of CKD by cause, glomerular filtration rate category, and albuminuria category) according to their UPCR data, a significant proportion of subjects (277, 77.0%) moved from the A2 category into A1, which is a less severe category. Conversely, 21 subjects (5.8%) were reclassified into a more severe category (A3). Thus, a dipstick test may produce a non-negligible number of false negatives as well as a large number of false positives. Similarly, the classifications of more than half of the subjects with (1+) or more severe proteinuria were changed based on their UPCR results. CONCLUSION: The dipstick urinalysis for proteinuria appears less reliable than expected, suggesting that the quantitative measurement of urine protein should be performed even during mass health checkups to ensure the early detection and prevention of CKD.
BACKGROUND: The dipstick urinalysis for proteinuria has been used for chronic kidney disease (CKD) screening at community-based health checkups; however, it has major drawbacks in that the result is only semi-quantitative and is influenced by urine concentration. METHODS: We conducted urine protein/creatinine ratio (UPCR) measurements of 590 participants who showed a result of more than trace proteinuria on a dipstick analysis and evaluated the usefulness of UPCR measurements in community-based health checkups. RESULTS: The UPCR values increased in accordance with the severity of the dipstick test findings, but statistical significance was only obtained between (±) and (1+), between (±) and (2+), and between (±) and (3+) groups. When the participants with (±) proteinuria were subjected to CGA classification (a classification of CKD by cause, glomerular filtration rate category, and albuminuria category) according to their UPCR data, a significant proportion of subjects (277, 77.0%) moved from the A2 category into A1, which is a less severe category. Conversely, 21 subjects (5.8%) were reclassified into a more severe category (A3). Thus, a dipstick test may produce a non-negligible number of false negatives as well as a large number of false positives. Similarly, the classifications of more than half of the subjects with (1+) or more severe proteinuria were changed based on their UPCR results. CONCLUSION: The dipstick urinalysis for proteinuria appears less reliable than expected, suggesting that the quantitative measurement of urine protein should be performed even during mass health checkups to ensure the early detection and prevention of CKD.
Authors: K Yamagata; K Ishida; T Sairenchi; H Takahashi; S Ohba; T Shiigai; M Narita; A Koyama Journal: Kidney Int Date: 2006-11-22 Impact factor: 10.612
Authors: Joris R Delanghe; Marc L De Buyzere; Matthijs Oyaert; Sigurd E Delanghe; Marijn M Speeckaert Journal: Clin Exp Nephrol Date: 2020-02-26 Impact factor: 2.801