Moist et al. studied the predictors of RKF loss in patients initiating either HD or PD using patients from the Dialysis Morbidity and Mortality Study (DMMS) which uses a randomly selected subset of dialysis patients from the U.S. Renal Data System (USRDS) (1). The predictors of more rapid RKF loss and adjusted odds ratios (AOR) are shown in the table below (n=1843).

Predictor	AOR	p value
Female	1.4	<0.001
Non-white	1.57	<0.001
History of diabetes	1.82	=0.006
History of CHF	1.32	=0.03
Time to follow-up (per month)	1.06	=0.03

PD patients had a 65% lower risk of RKF loss than those on HD (AOR = 0.35; p <0.001). Patients with higher serum calcium (AOR = 0.81 per mg/dl; p = 0.05), those who used an angiotensin-converting enzyme inhibitor (AOR = 0.68; p < 0.001), or who used a calcium channel blocker (AOR = 0.77; p = 0.01) were independently associated with decreased risk of RKF loss. As such the KDIGO guidelines have incorporated the use of these medications in dialysis patients with hypertension (2–4).

Another study that investigated possible predictors of RKF loss in incident PD patients (N=146), demonstrated that decline of RKF was independent of age, gender, dialysis modality, urgency of initiation of dialysis, smoking, vascular disease, blood pressure, medications (including angiotensin-converting enzyme inhibitors), duration of follow-up and peritonitis rate (5). The presence of a higher baseline RKF (mean: 6.2 ± 2.2 mL/min/1.73 m2) (AOR: 1.83, 95% CI: 1.39-2.40) and high dialysate to plasma (D/P) creatinine ratio (mean: 0.7 ± 0.11) at the start of PD were risk factors for rapid loss of RKF (AOR: 44.6, 95% CI: 1.05-1900). In addition, patients with a lower baseline RKF (mean: 3.7 ± 1.7 mL/min/1.73 m2), increased body surface area, high dietary protein intake and diabetes mellitus also had a faster onset of anuria. Serum phosphate levels were also associated with RKF loss: For every 1 mg/dL increase in serum phosphorus level, the HR for RKF loss was 1.32 (95% CI 1.15-1.50, P < 0.001) in males and 1.03 (95% CI 0.87-1.21, P = 0.750) for females (6). A small study by Caravaca et al. (7) reported that heart failure and creatinine clearance at PD initiation are a strong predictors of RKF loss. This study also suggested that chronic interstitial nephropathy is the strongest predialysis predictor for the preservation of RKF after onset of PD.

In a study of 522 incident PD and HD patients, Jansen and colleagues identified that higher diastolic blood pressure (P < 0.001) and a higher urinary protein loss (P < 0.001) were the primary factors negatively associated with loss of RKF at 12 months (8). They concluded that primary kidney disease did not affect the residual glomerular filtration rate. In agreement with prior studies, they showed that PD patients had a higher GFR (P < 0.001) than HD patients, and the relative difference increased over time (P = 0.04), and drop outs from PD were handled according to previously published studies (9–11). Investigation of possible effects of the dialysis procedure on the rate of decline in RKF between 0 and three months showed that intradialytic hypotension (P = 0.02) contributed to RKF decline in in HD and the presence of episodes with dehydration contributed in PD (P = 0.004). To add to this, Jo et al, identified that visit-to-visit variability in systolic blood pressure was a risk factor for rapid loss of RKF in PD patients studied retrospectively over 1 year (12).

In a study of 1524 patients who initiated HD a frequency ≤ 2 sessions per week, Lee et al. reported that high ultrafiltration rates led to a 73% increased risk of rapid RKF loss (13). Thus, it is important to obtain data on clearances in patients various regimens. Regular monitoring of RKF in dialysis could provide information useful for medication prescribing, meeting ultrafiltration goals, and making appropriate dose adjustments (14).

References:

1. Moist LM, Port FK, Orzol SM, et al. Predictors of loss of residual renal function among new dialysis patients. J Am Soc Nephrol. 2000;11(3):556-564. http://www.ncbi.nlm.nih.gov/pubmed/10703680. Accessed March 7, 2018.
2. Levin NW, Kotanko P, Eckardt K-U, et al. Blood pressure in chronic kidney disease stage 5D—report from a Kidney Disease: Improving Global Outcomes controversies conference. Kidney Int. 2010;77(4):273-284. doi:10.1038/ki.2009.469
3. Murton M, Goff-Leggett D, Bobrowska A, et al. Burden of Chronic Kidney Disease by KDIGO Categories of Glomerular Filtration Rate and Albuminuria: A Systematic Review. Adv Ther. January 2020. doi:10.1007/s12325-020-01568-8
4. Disease K, Global Outcomes Diabetes Work Group I. KDIGO 2020 Clinical Practice Guideline for Diabetes Management in Chronic Kidney Disease.; 2020. doi:10.1016/j.kint.2020.06.019
5. Johnson D, Mudge D, Sturtevant J, et al. Predictors of decline of residual renal function in new peritoneal dialysis patients – PubMed. Perit Dial Int . 2003;23(3):276-283. https://pubmed.ncbi.nlm.nih.gov/12938830/. Accessed March 3, 2021.
6. Shen J, Li W, Wang Y, et al. Higher serum phosphorus predicts residual renal function loss in male but not female incident peritoneal dialysis patients. J Nephrol. 2020;33(4):829-837. doi:10.1007/s40620-019-00670-7
7. Caravaca F, Dominguez C, Arrobas M. Predictors of loss of residual renal function in peritoneal dialysis patients. Perit Dial Int. 22(3):414-417. http://www.ncbi.nlm.nih.gov/pubmed/12227403. Accessed September 18, 2017.
8. Jansen MAM, Hart AAM, Korevaar JC, Dekker FW, Boeschoten EW, Krediet RT. Predictors of the rate of decline of residual renal function in incident dialysis patients. Kidney Int. 2002;62(3):1046-1053. doi:10.1046/j.1523-1755.2002.00505.x
9. Lysaght MJ, Vonesh EF, Gotch F, et al. The influence of dialysis treatment modality on the decline of remaining renal function. ASAIO Trans. 37(4):598-604. http://www.ncbi.nlm.nih.gov/pubmed/1768496. Accessed March 7, 2018.
10. Misra M, Vonesh E, Van Stone JC, Moore HL, Prowant B, Nolph KD. Effect of cause and time of dropout on the residual GFR: a comparative analysis of the decline of GFR on dialysis. Kidney Int. 2001;59(2):754-763. doi:10.1046/j.1523-1755.2001.059002754.x
11. Misra M, Vonesh ED, Churchill DN, Moore HL, Stone JC Van, Nolph KD. Preservation of Glomerular Filtration Rate on Dialysis When Adjusted for Patient Dropout. Vol 57.; 2000. doi:10.1046/j.1523-1755.2000.00891.x
12. Kyu Oh Y, Ah Jo H, Nam An J, Pyo Lee J, Oh K-H, Soo Lim C. Effects of Visit-to-Visit Variability in SBP on PD Patients Visit-to-Visit Variability in Systolic Blood Pressure Is a Risk Factor for Rapid Loss of Residual Renal Function in Peritoneal Dialysis Patients. Tohoku J Exp Med. 2015;235(4):295-304. doi:10.1620/tjem.235.295
13. Lee YJ, Okuda Y, Sy J, et al. Ultrafiltration Rate, Residual Kidney Function, and Survival Among Patients Treated With Reduced-Frequency Hemodialysis. Am J Kidney Dis. 2020;75(3):342-350. doi:10.1053/j.ajkd.2019.08.019
14. Rocco M, Daugirdas JT, Depner TA, et al. KDOQI Clinical Practice Guideline for Hemodialysis Adequacy: 2015 Update. Am J Kidney Dis. 2015;66(5):884-930. doi:10.1053/j.ajkd.2015.07.015

P/N 101801-01 Rev B 3/2021