Background and objectives Residual kidney function can be assessed by simply measuring urine volume, calculating GFR using 24-hour urine collection, or estimating GFR using the proposed equation (eGFR). We aimed to investigate the relative prognostic value of these residual kidney function parameters in patients on dialysis. Design, setting, participants, & measurements Using the database from a nationwide prospective cohort study, we compared differential implications of the residual kidney function indices in 1946 patients on dialysis at 36 dialysis centers in Korea between August 1, 2008 and December 31, 2014. Residual GFR calculated using 24-hour urine collection was determined by an average of renal urea and creatinine clearance on the basis of 24-hour urine collection. eGFR-urea, creatinine and eGFR b2 -microglobulin were calculated from the equations usingserum urea and creatinine and b2 -microglobulin, respectively. The primary outcome was all-cause death. Results During a mean follow-up of 42 months, 385 (19.8%) patients died. In multivariable Cox analyses, residual urine volume (hazard ratio, 0.96 per 0.1-L/d higher volume; 95% confidence interval, 0.94 to 0.98) and GFR calculated using 24-hour urine collection (hazard ratio, 0.98; 95% confidence interval, 0.95 to 0.99) were independently associated with all-cause mortality. In 1640 patients who had eGFR b2 -microglobulin data, eGFR b2 -microglobulin (hazard ratio, 0.98; 95% confidence interval, 0.96 to 0.99) was also significantly associated with all-cause mortality as well as residual urine volume (hazard ratio, 0.96 per 0.1-L/d higher volume; 95% confidence interval, 0.94 to 0.98) and GFR calculated using 24-hour urine collection (hazard ratio, 0.97; 95% confidence interval, 0.95 to 0.99). When each residual kidney function index was added to the base model, only urine volume improved the predictability for all-cause mortality (net reclassification index =0.11, P=0.01; integrated discrimination improvement =0.01, P=0.01). Conclusions Higher residual urine volume was significantly associated with a lower risk of death and exhibited a stronger association with mortality than GFR calculated using 24-hour urine collection and eGFR-urea, creatinine. These results suggest that determining residual urine volume may be beneficial to predict patient survival in patients on dialysis.
|Number of pages||9|
|Journal||Clinical Journal of the American Society of Nephrology|
|Publication status||Published - 2017|
Bibliographical noteFunding Information:
The authors extend sincere appreciation to all participants and investigators of the cohort study (Clinical Research Center for End-Stage Renal Disease) in Korea. This work was supported by the Brain Korea PLUS 21 Project for Medical Science, Yonsei University; National Research Foundation of Korea grant 2011-0030711 funded by the Korean Government (Ministry of Education, Science, and Technology); and grant HC15C1129 of the Korea Healthcare Technology R&D Project through the Korean Heath Industry Development Institute funded by the Ministry of Health & Welfare, Republic of Korea.
All Science Journal Classification (ASJC) codes
- Critical Care and Intensive Care Medicine