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Kidney Week

Abstract: FR-PO894

HEMO Study Results Suggest that “Clinically Negligible” Residual Kidney Function (RKF) Is a Significant Contributor to Uremic Solute Clearance

Session Information

Category: Dialysis

  • 607 Dialysis: Epidemiology, Outcomes, Clinical Trials - Non-Cardiovascular


  • Toth-Manikowski, Stephanie M., Johns Hopkins University School of Medicine, Baltimore, Maryland, United States
  • Sirich, Tammy L., Stanford University, Palo Alto, California, United States
  • Hostetter, Thomas H., Case Western Reserve University, Cleveland, Ohio, United States
  • Hwang, Seungyoung, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States
  • Coresh, Josef, Welch Center for Prevention, Epidemiology & Clinical Research, Baltimore, Maryland, United States
  • Powe, Neil R., Priscilla Chan and Mark Zuckerberg San Francisco General Hospital & University of California SF, San Francisco, California, United States
  • Shafi, Tariq, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States

RKF is thought to exert its beneficial effects through improved clearance of uremic toxins but the level of native kidney function where this clearance becomes negligible is not known. The HEMO study excluded patients with RKF >1.5 mL/min, as a level below was regarded as “clinically negligible.” We aimed to assess whether the levels of non-urea solutes associated with clinical outcomes differed among patients with this “clinically negligible” RKF compared to those with no RKF.


We measured 8 non-urea solutes in plasma from 1,280 patients of the HEMO Study 3-6 months post-randomization. We calculated the relative difference in solute levels among patients with and without RKF and compared it to the relative difference achieved by high vs standard hemodialysis (HD) dose (mean Kt/Vurea 1.7 vs 1.3, respectively).


At baseline, 34% of patients had “clinically negligible” RKF (mean 0.7±0.4 mL/min); 66% had no RKF. Those with RKF were older, had more recent onset of dialysis, and had lower UF requirements than those without RKF. Patients with RKF had significantly lower non-urea solute levels than patients without RKF. The differences were comparable or more pronounced than in those randomized to high HD dose (Table).


Even at a very low level, RKF is not “negligible” as it continues to provide clearance of solutes associated with clinical outcomes.

Effect of RKF on Uremic Solutes in 1,280 HEMO Participants
 RKF (N=433) vs No RKF (N=847)High HD Dose (N=638) vs Standard HD Dose (N=643)*
Solute% Differencep^% Differencep
P-Cresol Sulfate8%0.0032%0.46
Indoxyl Sulfate-11%0.001-11%<0.001
Asymmetric Dimethylarginine-4%0.0090.5%0.74
Symmetric Dimethylarginine-7%0.001-4%0.02

*As reported previously (Meyer T. JASN.2016). ^Adjusted for age, sex, race, and Kt/Vurea


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