Bolesław Rutkowski1, Paul Tam2, Frank M van der Sande3, Andreas Vychytil4, Vedat Schwenger5, Rainer Himmele6, Adelheid Gauly7. 1. Department of Nephrology, Medical University of Gdańsk, Gdańsk, Poland. 2. Scarborough General Hospital, Toronto, Ontario, Canada. 3. Division of Nephrology, Department of Internal Medicine, Maastricht University Medical Center, Maastricht, the Netherlands. 4. Division of Nephrology and Dialysis, Department of Medicine III, Medical University of Vienna, Vienna, Austria. 5. Department of Nephrology, University of Heidelberg, Heidelberg, Germany. 6. Fresenius Medical Care North America, Waltham, MA. 7. Fresenius Medical Care, Bad Homburg, Germany. Electronic address: adelheid.gauly@fmc-ag.com.
Abstract
BACKGROUND:Peritoneal dialysis (PD) solutions with reduced sodium content may have advantages for hypertensive patients; however, they have lower osmolarity and solvent drag, so the achieved Kt/Vurea may be lower. Furthermore, the increased transperitoneal membrane sodium gradient can influence sodium balance with consequences for blood pressure (BP) control. STUDY DESIGN: Prospective, randomized, double-blind clinical trial to prove the noninferiority of total weekly Kt/Vurea with low-sodium versus standard-sodium PD solution, with the lower confidence limit above the clinically accepted difference of -0.5. SETTING & PARTICIPANTS: Hypertensive patients (≥ 1 antihypertensive drug, including diuretics, or office systolic BP ≥ 130 mmHg) on continuous ambulatory PD therapy from 17 sites. INTERVENTION: 108 patients were randomly assigned (1:1) to 6-month treatments with either low-sodium (125 mmol/L of sodium; 1.5%, 2.3%, or 4.25% glucose; osmolarity, 338-491 mOsm/L) or standard-sodium (134 mmol/L of sodium; 1.5%, 2.3%, or 4.25% glucose; osmolarity, 356-509 mOsm/L) PD solution. OUTCOMES: Primary end point: weekly total Kt/Vurea; secondary outcomes: BP control, safety, and tolerability. MEASUREMENTS: Total Kt/Vurea was determined from 24-hour dialysate and urine collection; BP, by office measurement. RESULTS:Total Kt/Vurea after 12 weeks was 2.53 ± 0.89 in the low-sodium group (n = 40) and 2.97 ± 1.58 in the control group (n = 42). The noninferiority of total Kt/Vurea could not be confirmed. There was no difference for peritoneal Kt/Vurea (1.70 ± 0.38 with low sodium, 1.77 ± 0.44 with standard sodium), but there was a difference in renal Kt/Vurea (0.83 ± 0.80 with low sodium, 1.20 ± 1.54 with standard sodium). Mean daily sodium removal with dialysate at week 12 was 1.188 g higher in the low-sodium group (P < 0.001). BP changed marginally with standard-sodium solution, but decreased with low-sodium PD solution, resulting in less antihypertensive medication. LIMITATIONS: Broader variability of study population than anticipated, particularly regarding residual kidney function. CONCLUSIONS: The noninferiority of the low-sodium PD solution for total Kt/Vurea could not be proved; however, it showed beneficial clinical effects on sodium removal and BP.
RCT Entities:
BACKGROUND: Peritoneal dialysis (PD) solutions with reduced sodium content may have advantages for hypertensivepatients; however, they have lower osmolarity and solvent drag, so the achieved Kt/Vurea may be lower. Furthermore, the increased transperitoneal membrane sodium gradient can influence sodium balance with consequences for blood pressure (BP) control. STUDY DESIGN: Prospective, randomized, double-blind clinical trial to prove the noninferiority of total weekly Kt/Vurea with low-sodium versus standard-sodium PD solution, with the lower confidence limit above the clinically accepted difference of -0.5. SETTING & PARTICIPANTS: Hypertensivepatients (≥ 1 antihypertensive drug, including diuretics, or office systolic BP ≥ 130 mmHg) on continuous ambulatory PD therapy from 17 sites. INTERVENTION: 108 patients were randomly assigned (1:1) to 6-month treatments with either low-sodium (125 mmol/L of sodium; 1.5%, 2.3%, or 4.25% glucose; osmolarity, 338-491 mOsm/L) or standard-sodium (134 mmol/L of sodium; 1.5%, 2.3%, or 4.25% glucose; osmolarity, 356-509 mOsm/L) PD solution. OUTCOMES: Primary end point: weekly total Kt/Vurea; secondary outcomes: BP control, safety, and tolerability. MEASUREMENTS: Total Kt/Vurea was determined from 24-hour dialysate and urine collection; BP, by office measurement. RESULTS: Total Kt/Vurea after 12 weeks was 2.53 ± 0.89 in the low-sodium group (n = 40) and 2.97 ± 1.58 in the control group (n = 42). The noninferiority of total Kt/Vurea could not be confirmed. There was no difference for peritoneal Kt/Vurea (1.70 ± 0.38 with low sodium, 1.77 ± 0.44 with standard sodium), but there was a difference in renal Kt/Vurea (0.83 ± 0.80 with low sodium, 1.20 ± 1.54 with standard sodium). Mean daily sodium removal with dialysate at week 12 was 1.188 g higher in the low-sodium group (P < 0.001). BP changed marginally with standard-sodium solution, but decreased with low-sodium PD solution, resulting in less antihypertensive medication. LIMITATIONS: Broader variability of study population than anticipated, particularly regarding residual kidney function. CONCLUSIONS: The noninferiority of the low-sodium PD solution for total Kt/Vurea could not be proved; however, it showed beneficial clinical effects on sodium removal and BP.
Authors: Jennifer E Flythe; Tara I Chang; Martin P Gallagher; Elizabeth Lindley; Magdalena Madero; Pantelis A Sarafidis; Mark L Unruh; Angela Yee-Moon Wang; Daniel E Weiner; Michael Cheung; Michel Jadoul; Wolfgang C Winkelmayer; Kevan R Polkinghorne Journal: Kidney Int Date: 2020-03-08 Impact factor: 10.612