A randomized trial of dietary sodium restriction in CKD

Abstract

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 doubleblind 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 compositionmonitor), 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 patientswithmoderate-to-severe CKD. The magnitude of change was more pronounced than the magnitude reported in patients without CKD, suggesting that patients withCKDare particularly salt sensitive. Although studieswith 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. Copyright © 2013 by the American Society of Nephrology.