The association of urinary sodium excretion and the need for renal replacement therapy in advanced chronic kidney disease: a cohort study

Andrea Mazarova, Amber O Molnar, Ayub Akbari, Manish M Sood, Swapnil Hiremath, Kevin D Burns, Timothy O Ramsay, Ranjeeta Mallick, Gregory A Knoll, Marcel Ruzicka, Andrea Mazarova, Amber O Molnar, Ayub Akbari, Manish M Sood, Swapnil Hiremath, Kevin D Burns, Timothy O Ramsay, Ranjeeta Mallick, Gregory A Knoll, Marcel Ruzicka

Abstract

Background: Restriction of dietary sodium is routinely recommended for patients with chronic kidney disease (CKD). Whether or not sodium intake is associated with the progression of CKD and mortality remains controversial. We evaluated the association of urinary sodium excretion (as a surrogate for sodium intake) on the need for renal replacement therapy and mortality in patients with advanced CKD.

Methods: We conducted a retrospective study of patients followed at a CKD clinic of a tertiary care hospital from January 2010 to December 2012. Adult patients with advanced CKD (estimated glomerular filtration rate (eGFR) <30 ml/min/1.73 m(2)) were included. Using a time-to-event analysis, we examined the association of urinary sodium excretion as a continuous and also as a categorical variable (categorized as low sodium diet - LSD (<100 mEq/day), medium sodium diet - MSD (100-150 mEq/day), and high sodium diet - HSD (>150 mEq/day) and the outcomes of interest. The primary outcome was defined as composite of progression to end-stage renal disease requiring any type of renal replacement therapy and mortality. The secondary outcome was change in eGFR/year.

Results: 341 patients (82 LSD, 116 MSD and 143 HSD) were included in the study (mean follow up of 1.5 years) with a mean eGFR decline of 2.7 ml/min/1.73 m(2)/year. 105 patients (31 %) required renal replacement therapy and 10 (3 %) died. There was no association between urinary sodium excretion and change in the eGFR or need for renal replacement therapy and mortality in crude or adjusted models (unadjusted HR 1.002; 95%CI 1.000-1.004, adjusted HR 1.001; 95%CI 0.998-1.004).

Conclusion: In patients with advanced CKD (eGFR < 30 ml/min/1.73 m(2)), sodium intake does not appear to impact the progression of CKD to end-stage renal disease; however, more definitive studies are needed.

Keywords: Chronic kidney disease; Sodium intake; Urinary sodium excretion; eGFR decline.

Figures

Fig. 1
Fig. 1
Kaplan Meier Curve for Sodium Groups. The analysis did not show any difference in time to composite outcome (renal replacement therapy + Death) among the three groups (P = 0.73)

References

    1. Coresh J, Turin TC, Matsushita K, Sang Y, Ballew SH, Appel LJ, et al. Decline in estimated glomerular filtration rate and subsequent risk of end-stage renal disease and mortality. JAMA. 2014;311(24):2518–2531. doi: 10.1001/jama.2014.6634.
    1. Stevens PE, Levin A. Kidney disease: improving global outcomes chronic kidney disease guideline development work group M. Evaluation and management of chronic kidney disease: synopsis of the kidney disease: improving global outcomes 2012 clinical practice guideline. Ann Intern Med. 2013;158(11):825–830. doi: 10.7326/0003-4819-158-11-201306040-00007.
    1. Smyth A, O'Donnell MJ, Yusuf S, Clase CM, Teo KK, Canavan M, et al. Sodium intake and renal outcomes: a systematic review. Am J Hypertens. 2014;27(10):1277–84. doi: 10.1093/ajh/hpt294.
    1. Campbell KL, Johnson DW, Bauer JD, Hawley CM, Isbel NM, Stowasser M, et al. A randomized trial of sodium-restriction on kidney function, fluid volume and adipokines in CKD patients. BMC Nephrol. 2014;15:57. doi: 10.1186/1471-2369-15-57.
    1. Fan L, Tighiouart H, Levey AS, Beck GJ, Sarnak MJ. Urinary sodium excretion and kidney failure in nondiabetic chronic kidney disease. Kidney Int. 2014;86(3):582–588. doi: 10.1038/ki.2014.59.
    1. McMahon EJ, Bauer JD, Hawley CM, Isbel NM, Stowasser M, Johnson DW, et al. A randomized trial of dietary sodium restriction in CKD. J Am Soc Nephrol. 2013;24(12):2096–2103. doi: 10.1681/ASN.2013030285.
    1. Levey AS, Bosch JP, Lewis JB, Greene T, Rogers N, Roth D. A more accurate method to estimate glomerular filtration rate from serum creatinine: a new prediction equation. Modification of Diet in Renal Disease Study Group. Ann Intern Med. 1999;130(6):461–470. doi: 10.7326/0003-4819-130-6-199903160-00002.
    1. Ginsberg JM, Chang BS, Matarese RA, Garella S. Use of single voided urine samples to estimate quantitative proteinuria. N Engl J Med. 1983;309(25):1543–1546. doi: 10.1056/NEJM198312223092503.
    1. Perrone RD, Madias NE, Levey AS. Serum creatinine as an index of renal function: new insights into old concepts. Clin Chem. 1992;38(10):1933–1953.
    1. Vogt L, Waanders F, Boomsma F, de Zeeuw D, Navis G. Effects of dietary sodium and hydrochlorothiazide on the antiproteinuric efficacy of losartan. J Am Soc Nephrol. 2008;19(5):999–1007. doi: 10.1681/ASN.2007060693.
    1. Smyth A, Dunkler D, Gao P, Teo KK, Yusuf S, O'Donnell MJ, et al. The relationship between estimated sodium and potassium excretion and subsequent renal outcomes. Kidney Int. 2014;86(6):1205–1212. doi: 10.1038/ki.2014.214.
    1. Vegter S, Perna A, Postma MJ, Navis G, Remuzzi G, Ruggenenti P. Sodium intake, ACE inhibition, and progression to ESRD. J Am Soc Nephrol. 2012;23(1):165–173. doi: 10.1681/ASN.2011040430.
    1. McQuarrie EP, Traynor JP, Taylor AH, Freel EM, Fox JG, Jardine AG, et al. Association between urinary sodium, creatinine, albumin, and long-term survival in chronic kidney disease. Hypertension. 2014;64(1):111–117. doi: 10.1161/HYPERTENSIONAHA.113.03093.
    1. Thomas MC, Moran J, Forsblom C, Harjutsalo V, Thorn L, Ahola A, et al. The association between dietary sodium intake, ESRD, and all-cause mortality in patients with type 1 diabetes. Diabetes Care. 2011;34(4):861–866. doi: 10.2337/dc10-1722.
    1. Lambers Heerspink HJ, Holtkamp FA, Parving HH, Navis GJ, Lewis JB, Ritz E, et al. Moderation of dietary sodium potentiates the renal and cardiovascular protective effects of angiotensin receptor blockers. Kidney Int. 2012;82(3):330–337. doi: 10.1038/ki.2012.74.
    1. Brown IJ, Tzoulaki I, Candeias V, Elliott P. Salt intakes around the world: implications for public health. Int J Epidemiol. 2009;38(3):791–813. doi: 10.1093/ije/dyp139.
    1. Gomi T, Shibuya Y, Sakurai J, Hirawa N, Hasegawa K, Ikeda T. Strict dietary sodium reduction worsens insulin sensitivity by increasing sympathetic nervous activity in patients with primary hypertension. Am J Hypertens. 1998;11(9):1048–1055. doi: 10.1016/S0895-7061(98)00126-5.
    1. Graudal NA, Galloe AM, Garred P. Effects of sodium restriction on blood pressure, renin, aldosterone, catecholamines, cholesterols, and triglyceride: a meta-analysis. JAMA. 1998;279(17):1383–1391. doi: 10.1001/jama.279.17.1383.
    1. Graudal N, Jurgens G, Baslund B, Alderman MH. Compared with usual sodium intake, low- and excessive-sodium diets are associated with increased mortality: a meta-analysis. Am J Hypertens. 2014;27(9):1129–1137. doi: 10.1093/ajh/hpu028.
    1. Rakova N, Juttner K, Dahlmann A, Schroder A, Linz P, Kopp C, et al. Long-term space flight simulation reveals infradian rhythmicity in human Na(+) balance. Cell Metab. 2013;17(1):125–131. doi: 10.1016/j.cmet.2012.11.013.

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