A Randomized Trial of Dietary Sodium Restriction in CKD

• Published in: Journal of the American Society of Nephrology Vol. 24; no. 12; pp. 2096 - 2103
• Main Authors: MCMAHON, Emma J, BAUER, Judith D, HAWLEY, Carmel M, ISBEL, Nicole M, STOWASSER, Michael, JOHNSON, David W, CAMPBELL, Katrina L
• Format: Journal Article
• Language: English
• Published: Washington, DC American Society of Nephrology 01.12.2013
• Subjects: Aged; Biological and medical sciences; Blood Pressure; Clinical Research; Cross-Over Studies; Diet, Sodium-Restricted - methods; Double-Blind Method; Female; Humans; Hypertension, Renal - diet therapy; Hypertension, Renal - epidemiology; Kidneys; Male; Medical sciences; Middle Aged; Nephrology. Urinary tract diseases; Nephropathies. Renovascular diseases. Renal failure; New Zealand; Patient Compliance - statistics & numerical data; Renal failure; Renal Insufficiency, Chronic - diet therapy; Renal Insufficiency, Chronic - epidemiology; Risk Factors; Risk Reduction Behavior; Sodium Chloride, Dietary - administration & dosage; Sodium Chloride, Dietary - adverse effects; Treatment Outcome; Urinary system involvement in other diseases. Miscellaneous; New Zealand; Kidney disease; Nephrology; Urinary system disease; Nutrition; Chronic kidney disease; Urology; Feeding; Randomization; Diet therapy; Diet; Sodium; Renal failure; Clinical trial
• DOI: 10.1681/asn.2013030285
• ISSN: 1046-6673

There is a paucity of quality evidence regarding the effects of sodium restriction in patients with CKD, particularly in patients with pre-end stage CKD, where controlling modifiable risk factors may be especially important for delaying CKD progression and cardiovascular events. We conducted a double-blind placebo-controlled randomized crossover trial assessing the effects of high versus low sodium intake on ambulatory BP, 24-hour protein and albumin excretion, fluid status (body composition monitor), renin and aldosterone levels, and arterial stiffness (pulse wave velocity and augmentation index) in 20 adult patients with hypertensive stage 3-4 CKD as phase 1 of the LowSALT CKD study. Overall, salt restriction resulted in statistically significant and clinically important reductions in BP (mean reduction of systolic/diastolic BP, 10/4 mm Hg; 95% confidence interval, 5 to 15 /1 to 6 mm Hg), extracellular fluid volume, albuminuria, and proteinuria in patients with moderate-to-severe CKD. The magnitude of change was more pronounced than the magnitude reported in patients without CKD, suggesting that patients with CKD are particularly salt sensitive. Although studies with longer intervention times and larger sample sizes are needed to confirm these benefits, this study indicates that sodium restriction should be emphasized in the management of patients with CKD as a means to reduce cardiovascular risk and risk for CKD progression.