Stephanie M Toth-Manikowski1, Tammy L Sirich2, Timothy W Meyer2, Thomas H Hostetter3, Seungyoung Hwang2, Natalie S Plummer2, Xin Hai3, Josef Coresh4,5, Neil R Powe6, Tariq Shafi2,4,5,7. 1. Department of Medicine, Division of Nephrology, University of Illinois at Chicago, Chicago, IL, USA. 2. Department of Medicine, Division of Nephrology, Johns Hopkins School of Medicine, Baltimore, MD, USA. 3. Department of Medicine, Palo Alto Veterans Affairs Health Care System, Stanford University, Palo Alto, CA, USA. 4. Department of Medicine, Case Western Reserve University, Cleveland, OH, USA. 5. Welch Center for Prevention, Epidemiology and Clinical Research, Johns Hopkins University, Baltimore, MD, USA. 6. Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA. 7. Department of Medicine, Priscilla Chan and Mark Zuckerberg San Francisco General Hospital, University of California, San Francisco, San Francisco, CA, USA.
Abstract
BACKGROUND: Residual kidney function (RKF) is thought to exert beneficial effects through clearance of uremic toxins. However, the level of native kidney function where clearance becomes negligible is not known. METHODS: We aimed to assess whether levels of nonurea solutes differed among patients with 'clinically negligible' RKF compared with those with no RKF. The hemodialysis study excluded patients with urinary urea clearance >1.5 mL/min, below which RKF was considered to be 'clinically negligible'. We measured eight nonurea solutes from 1280 patients participating in this study and calculated the relative difference in solute levels among patients with and without RKF based on measured urinary urea clearance. RESULTS: The mean age of the participants was 57 years and 57% were female. At baseline, 34% of the included participants had clinically negligible RKF (mean 0.7 ± 0.4 mL/min) and 66% had no RKF. Seven of the eight nonurea solute levels measured were significantly lower in patients with RKF than in those without RKF, ranging from -24% [95% confidence interval (CI) -31 to -16] for hippurate, -7% (-14 to -1) for trimethylamine-N-oxide and -4% (-6 to -1) for asymmetric dimethylarginine. The effect of RKF on plasma levels was comparable or more pronounced than that achieved with a 31% higher dialysis dose (spKt/Vurea 1.7 versus 1.3). Preserved RKF at 1-year follow-up was associated with a lower risk of cardiac death and first cardiovascular event. CONCLUSIONS: Even at very low levels, RKF is not 'negligible', as it continues to provide nonurea solute clearance. Management of patients with RKF should consider these differences.
BACKGROUND: Residual kidney function (RKF) is thought to exert beneficial effects through clearance of uremic toxins. However, the level of native kidney function where clearance becomes negligible is not known. METHODS: We aimed to assess whether levels of nonurea solutes differed among patients with 'clinically negligible' RKF compared with those with no RKF. The hemodialysis study excluded patients with urinary urea clearance >1.5 mL/min, below which RKF was considered to be 'clinically negligible'. We measured eight nonurea solutes from 1280 patients participating in this study and calculated the relative difference in solute levels among patients with and without RKF based on measured urinary urea clearance. RESULTS: The mean age of the participants was 57 years and 57% were female. At baseline, 34% of the included participants had clinically negligible RKF (mean 0.7 ± 0.4 mL/min) and 66% had no RKF. Seven of the eight nonurea solute levels measured were significantly lower in patients with RKF than in those without RKF, ranging from -24% [95% confidence interval (CI) -31 to -16] for hippurate, -7% (-14 to -1) for trimethylamine-N-oxide and -4% (-6 to -1) for asymmetric dimethylarginine. The effect of RKF on plasma levels was comparable or more pronounced than that achieved with a 31% higher dialysis dose (spKt/Vurea 1.7 versus 1.3). Preserved RKF at 1-year follow-up was associated with a lower risk of cardiac death and first cardiovascular event. CONCLUSIONS: Even at very low levels, RKF is not 'negligible', as it continues to provide nonurea solute clearance. Management of patients with RKF should consider these differences.
Authors: Tammy L Sirich; Kara Fong; Brett Larive; Gerald J Beck; Glenn M Chertow; Nathan W Levin; Alan S Kliger; Natalie S Plummer; Timothy W Meyer Journal: Kidney Int Date: 2017-01-12 Impact factor: 10.612
Authors: Timothy W Meyer; Tammy L Sirich; Kara D Fong; Natalie S Plummer; Tariq Shafi; Seungyoung Hwang; Tanushree Banerjee; Yunnuo Zhu; Neil R Powe; Xin Hai; Thomas H Hostetter Journal: J Am Soc Nephrol Date: 2016-03-29 Impact factor: 10.121
Authors: D P Brooks; G R Rhodes; P Woodward; V K Boppana; F M Mallon; H E Griffin; L B Kinter Journal: Clin Sci (Lond) Date: 1989-12 Impact factor: 6.124
Authors: Marinaldo Pacífico Cavalcanti Neto; Jailane de Souza Aquino; Larissa de Fátima Romão da Silva; Ruanniere de Oliveira Silva; Keyth Sulamitta de Lima Guimarães; Yohanna de Oliveira; Evandro Leite de Souza; Marciane Magnani; Hubert Vidal; José Luiz de Brito Alves Journal: Pharmacol Res Date: 2018-02-14 Impact factor: 7.658