Ching-Wei Tsai1, Han-Chun Huang2, Ni Tien3, Chih-Wei Chung2, Hsien-Tsai Chiu2, Hung-Chieh Yeh4, Chin-Chi Kuo5. 1. Division of Nephrology, Department of Internal Medicine, China Medical University Hospital and College of Medicine, China Medical University, Taichung, Taiwan; Big Data Center, China Medical University Hospital and China Medical University, Taichung, Taiwan. 2. Big Data Center, China Medical University Hospital and China Medical University, Taichung, Taiwan. 3. Department of Laboratory Medicine, China Medical University Hospital and China Medical University, Taichung, Taiwan; Department of Medical Laboratory Science and Biotechnology, China Medical University, Taichung, Taiwan. 4. Division of Nephrology, Department of Internal Medicine, China Medical University Hospital and College of Medicine, China Medical University, Taichung, Taiwan. 5. Division of Nephrology, Department of Internal Medicine, China Medical University Hospital and College of Medicine, China Medical University, Taichung, Taiwan; Big Data Center, China Medical University Hospital and China Medical University, Taichung, Taiwan. Electronic address: d25725@mail.cmuh.org.tw.
Abstract
BACKGROUND: The clinical importance of random urine creatinine concentration in CKD population remains undetermined. Earlier studies found that lower 24-h urine creatinine excretion was associated with the risk of ESRD and all-cause mortality among CKD patients. METHODS: We modeled the longitudinal trajectories of serial random urine creatinine among 4689 CKD patients enrolled in a national registry-based pre-ESRD program between 2003 and 2015 at a tertiary medical center. Other biochemical parameters including kidney function and serum albumin were regularly evaluated. Primary study outcomes were ESRD requiring maintenance dialysis and all-cause mortality. RESULTS: By group-based trajectory modeling, the urine creatinine trajectories were characterized into three patterns: (1) stable low; (2) medium; and (3) high-declining. The adjusted hazard ratio of incident ESRD and all-cause mortality increased by 6% (95% CI: 1-12%) and 9% (95% CI: 2-17%), respectively, for each 20 mg/dL reduction in baseline random urine creatinine concentration. Consistently, there was a significant inverse linear dose-response relationship between baseline random urine creatinine and incident ESRD, but not all-cause mortality. Compared to patients with "medium" and "high-declining" urine creatinine trajectories combined, the adjusted hazard ratio for incidental ESRD among patients with a "stable-low" trajectory who had serial random urine creatinine concentrations stably below 100 mg/dL was 1.46 (95% CI: 1.00-2.12) after considering the competing risk of death. CONCLUSIONS: Random urine creatinine not only serves as a common urinary concentration corrector but has its own clinical significance in risk stratification and outcome prediction in patients with advanced CKD.
BACKGROUND: The clinical importance of random urine creatinine concentration in CKD population remains undetermined. Earlier studies found that lower 24-h urine creatinine excretion was associated with the risk of ESRD and all-cause mortality among CKDpatients. METHODS: We modeled the longitudinal trajectories of serial random urine creatinine among 4689 CKDpatients enrolled in a national registry-based pre-ESRD program between 2003 and 2015 at a tertiary medical center. Other biochemical parameters including kidney function and serum albumin were regularly evaluated. Primary study outcomes were ESRD requiring maintenance dialysis and all-cause mortality. RESULTS: By group-based trajectory modeling, the urine creatinine trajectories were characterized into three patterns: (1) stable low; (2) medium; and (3) high-declining. The adjusted hazard ratio of incident ESRD and all-cause mortality increased by 6% (95% CI: 1-12%) and 9% (95% CI: 2-17%), respectively, for each 20 mg/dL reduction in baseline random urine creatinine concentration. Consistently, there was a significant inverse linear dose-response relationship between baseline random urine creatinine and incident ESRD, but not all-cause mortality. Compared to patients with "medium" and "high-declining" urine creatinine trajectories combined, the adjusted hazard ratio for incidental ESRD among patients with a "stable-low" trajectory who had serial random urine creatinine concentrations stably below 100 mg/dL was 1.46 (95% CI: 1.00-2.12) after considering the competing risk of death. CONCLUSIONS: Random urine creatinine not only serves as a common urinary concentration corrector but has its own clinical significance in risk stratification and outcome prediction in patients with advanced CKD.