Protection of erythropoietin and vitamin D production can help preserve kidney output in ESKD
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Preservation of residual kidney function reduces morbidity, improves survival and offers other benefits to patients with ESKD. However, more study is needed to understand the mechanisms of residual kidney function along with methods and treatments that can successfully extend preservation, according to a recently published study.
“Preservation of [residual kidney function] RKF requires techniques to measure it accurately to be able to uncover factors that accelerate its loss and interventions that preserve it and ultimately to individualize therapy,” Tian Li, MD, of the department of medicine at State University of New York Downstate Medical Center in Brooklyn, and colleagues from Georgetown University Hospital, wrote.
Li and colleagues identified some factors from a literature search that might help with preserving RKF. These include the following:
- improved volume control;
- clearance of protein-bound and middle molecules; and
- reduced inflammation and preserved erythropoietin and vitamin D production.
The authors cited three trials that have addressed the value of preserving RKF among patients with ESKD, but most of the success has been seen among those who choose peritoneal dialysis (PD).
“Unfortunately, the importance of RKF is still not well appreciated in [hemodialysis], in part because the ESRD Quality Incentive Program does not accept Kt/V adjustment for RKF, despite (a) Kidney Disease Outcomes Quality Initiative guideline suggesting that Kt/Vurea targets can be reduced for patients with a residual renal urea clearance [of greater than] 2 mL/min/1.73 m2.”
Studies have shown that patients using PD had a 65% lower risk of loss of RKF than those treated with HD, the researchers noted. In the studies, “this was attributed to better hemodynamic stability,” the authors wrote. “Female sex, non-white race, prior history of diabetes or congestive heart failure and time to follow-up were shown to be independent predictors of loss of RKF.”
Patients on hemodialysis with higher post-dialysis mean arterial pressure (MAP), higher pre-dialysis serum calcium and usage of 3-hydroxy-3-methyl-glutaryl-coenzyme A reductase inhibitors were reported to have a better preservation of RKF.
A study on the effect of angiotensin-converting enzyme (ACE) inhibitors and angiotensin receptor blockers (ARB) on preserving RKF among patients on PD showed that, compared with other antihypertensive drugs, the long-term use (greater than 12 months) of ACE inhibitors and ARB had additional and similar benefits in preserving RKF, but no effect on reducing proteinuria. Incremental dialysis, use of biocompatible membranes and ultrapure dialysate in patients on hemodialysis and use of biocompatible solutions in patients on PD have also been reviewed.
“The effects of [blood pressure] on RKF are not clear but care is needed to avoid excessive swings and prolonged hypotension,” the authors wrote. The use of diuretics in patients treated by continuous ambulatory PD can improve volume status and minimize the need for higher glucose-containing solution; a prospective trial of patients randomized to 250 mg per day of furosemide “found a significantly better preservation of urine volume over 12 months, but no beneficial effects on urea and creatinine clearance.”
RKF “is an independent factor that can predict morbidity, mortality and quality of life,” the authors concluded. “RKF should be monitored regularly in all modalities and dialysis prescriptions should be tailored periodically to the gradual loss of renal clearance.” – by Mark E. Neumann
Disclosures: The authors report no relevant financial disclosures.