Influence of Dialysate Sodium Prescription on Skin and Muscle Sodium Concentration

Sodium and water are the main determinants of body volume status BP. Because sodium excreted by kidneys, maintenance homeostasis is particularly challenging in hemodialysis (HD) patients. Various interventions have been proposed to avoid fluid accumulation HD patients, including restriction dietary intake, ultrafiltration reach dry weight, increased plasma dialysate concentration ([Na+]D) gradient. However, strong evidence for selection [Na+]D lacking there was no consensus recent KDOQI guideline.1Flythe J.E. Chang T.I. Gallagher M.P. et al.Blood pressure management dialysis: conclusions from a Kidney Disease: Improving Global Outcomes (KDIGO) Controversies Conference.Kidney Int. 2020; 97: 861-876Abstract Full Text PDF PubMed Scopus (12) Google Scholar Most studies focused on osmotically active sodium. this concept has challenged after long-term balance study humans protracted space flight simulation.2Rakova N. Jüttner K. Dahlmann A. al.Long-term simulation reveals infradian rhythmicity human Na(+) balance.Cell Metab. 2013; 17: 125-131Abstract (229) Scholar,3Titze J. Maillet Lang R. terrestrial station study.Am J Dis. 2002; 40: 508-516Abstract (99) Animal-based experimental confirmed that high-salt diet rats leads hypertonic nonosmotically skin, mobilizable salt restriction.4Titze Ilies C. al.Osmotically inactive skin Na+ storage rats.Am Physiol Renal Physiol. 2003; 285: F1108-F1117Crossref (167) Scholar,5Schafflhuber M. Volpi al.Mobilization growth 2007; 292: F1490-F1500Crossref (81) Improved imaging technology using magnetic resonance (23Na MRI) now allows measurement tissue content vivo. We hypothesized prescription determines longer-term To explore we studied impact muscle determined MRI patients receiving different prescriptions. Participants were recruited prevalent population 2 dialysis units London Regional Program (Ontario, Canada) where standard care identical, except use 137 mmol/L 1 unit ([137]D) 140 other ([140]D). included 36 participants allocated prescriptions protocol basis (Fig S1). established at least 3 months included. underwent an scan lower leg. Blood blood tests done same day as MRI. carried out 3T (Discovery MR750; General Electric Healthcare) system similarly previously described methods6Qirjazi E. Salerno F.R. Akbari al.Tissue concentrations chronic kidney disease leg sodium-23 [Published online April 6, 2020]. Nephrol Dial Transplant.https://doi.org/10.1093/ndt/gfaa036Google (Item A sample size 18 per group would be sufficient detect difference 7 (less than observed previous studies) based upon deviation 14%, significance level 0.05, 80% power. Median age 65 (range, 40-82) years; 61% men, had diabetes, 86% hypertensive. vintage 20 (3-144) 58% measurable RKF (Table 1). their median 11 (3-23) versus 16 (4-115) [137]D [140]D groups, respectively (P = 0.03).Table 1Participants’ Characteristics Time StudyWhole Population (N 36)[Na+]D Prescription137 (n 18)140 18)Age, y65 (40-82)66 (47-79)65 (40-82)Male sex22 (61%)10 (55%)12 (66%)Height, cm171.5 (145-195)170 (156-190)174 (155-195)Weight, kg93 (58-126)88 (62-126)96 (58-120)Body mass index, kg/m232.2 (21.1-43.0)31.5 (21.6-41.1)32.4 (21.4-43)Systolic BP, mm Hg132 (95-181)128 (97-181)133 (95-171)Diastolic Hg77 (56-100)73 (61-90)79 (43-99)Hypertension31 (86%)15 (83%)16 (88%)Diabetes mellitus22 (57%)12 (66%)Cardiovascular events20 (62%)8 (44%)HD vintage, mo20 (3-144)19 (3-39)22 (4-44)Dialysis session length, h/wk12 (6-13.5)11 (7-13)12 (6-13.5)Fistula vascular access17 (47%)6 (33%)11 (61%)RKF21 (58%)11 (55%)Blood flow, mL/min384 (331-400)378 (331-398)387 (334-400)Kt/V1.26 (0.64-1.9)1.28 (0.64-1.9)1.26 (1.1-1.7)Ultrafiltration volume, mL2.3 (0-4)2 (0.4-4)2.5 (0-4)Intradialytic kg2 (1.3-5)1.65 (0-3.2)2.3 (0.1-5)Pre-HD Serum Na+, mmol/L137 (129-144)136 (129-143)138aP < 0.05 vs 137mmol/L group, Mann-Whitney test. (133-141)Pre-HD K+, mmol/L4.5 (3.3-6.5)4.3 (3.3-6.5)4.2 (3.5-5.6)Note: Data expressed (minimum-maximum) or count (percentage).Abbreviations: pressure; RKF, residual function.a P Open table new tab Note: (percentage). Abbreviations: function. Figure 1A B displays 23Na patient with another [140]D. significantly (23 [range, 15-42] mmol/L) (31 12-49] mmol/L; 0.002; Fig 1C). Muscle not (26 19-38] 29 18-41] mmol/L, respectively; 0.4; 1D). Skin (28 13-49] correlated 0.1). systolic BP (r 0.5, 0.01) while borderline significant 0.38, 0.05) correlation 1E F). between without 0.6 0.8), <20 >20 0.8 0.7), permcath fistula 0.4 0.5; S2). Our results demonstrate capable reducing showed more strongly left ventricular mass7Schneider Raff U. Kopp al.Skin correlates hypertrophy CKD.J Am Soc Nephrol. 2017; 28: 1867-1876Crossref (108) total overhydration, although focusing volume-based consequences reported change index.8Marshall M.R. Vandal A.C. de Zoysa J.R. al.Effect low-sodium conventional home self-care satellite facility patients: randomized clinical trial.J 31: 1078-1091Crossref (6) In present study, well matched prescriptions, suggesting (in absence confounding factors) higher storage. Tissue levels seem broadly consistent patients,6Qirjazi Scholar,9Dahlmann Dörfelt Eicher F. al.Magnetic resonance-determined removal stores patients.Kidney 2015; 87: 434-441Abstract (128) Scholar,10Kopp Linz P. Maier al.Elevated deposition type diabetes detected imaging.Kidney 2018; 93: 1191-1197Abstract (44) highlighting reproducibility measurement. measured just once, preintervention baseline Previous suggested may buffer intake hemodynamic salt. able link increase outcomes cannot robustly comment causality. findings emphasize need elucidate potential outcomes. This also suggests used tool dynamically personalize choices. Research idea design: CWM, data acquisition: AA; analysis/interpretation: SL, FRS, statistical analysis: SL; supervision mentorship: CWM. Each author contributed important intellectual during manuscript drafting revision agrees personally accountable individual’s own contributions ensure questions pertaining accuracy integrity any portion work, even one which directly involved, appropriately investigated resolved, documentation literature if appropriate. project funded Can-SOLVE CKD Network Canadian Institutes Health Strategy Patient-Oriented Research. The authors declare they relevant financial interests. like thank Tanya Tamasi, Justin Dorie, Patricia Jarosz support Received June 11, 2020. Evaluated external peer reviewers, direct editorial input Statistics/Methods Editor, Associate Editor-in-Chief. Accepted revised form November 14, Download .pdf (.23 MB) Help pdf files Supplementary File (PDF)Figures S1-S2; Item S1.