Cochrane for Clinicians

Putting Evidence into Practice

Effects of Altered Dietary Salt Intake in Patients with Chronic Kidney Disease

 

Am Fam Physician. 2017 Apr 1;95(7):423-424.

Author disclosure: No relevant financial affiliations.

Clinical Question

In patients with chronic kidney disease (CKD), does altering dietary salt intake affect risk factors or delay cardiovascular or renal complications?

Evidence-Based Answer

Reducing salt intake lowers blood pressure and reduces proteinuria in patients with CKD, but there is no evidence to determine whether lowering salt consumption leads to clinically significant reductions in end-stage renal disease, cardiovascular events, or all-cause mortality.1 (Strength of Recommendation: C, based on a review of limited, though consistent, high-quality disease-oriented studies.)

Practice Pointers

CKD is a progressive condition often encountered by family physicians; it is both a complication of commonly encountered disease (e.g., hypertension, diabetes mellitus)2 and an independent risk factor for cardiovascular disease.3 Patients with end-stage renal disease incur dramatically higher costs of care4 and have markedly increased mortality.5 Reliable interventions that may delay or prevent progression of CKD have not been fully elucidated. Restriction of dietary sodium (salt) intake is often recommended in these patients. This review sought to evaluate the benefits and harms of this intervention in patients with CKD.

The authors identified eight randomized controlled trials of parallel or crossover design that compared salt-restricted to higher-salt diets in 258 participants.1 Some of the studies provided supplemental salt tablets to achieve a high-salt diet, and others used dietary counseling as the intervention for the low-salt diet. Patients on a low-salt diet had a reduction in blood pressure, with an effect size comparable to that of a single antihypertensive medication. Systolic blood pressure was reduced by 9 mm Hg (95% confidence interval, 6 to 11) and diastolic blood pressure was reduced by 4 mm Hg (95% confidence interval, 2 to 5).

The two studies conducted in patients with more advanced kidney disease (one study in patients receiving dialysis and one study in p

Author disclosure: No relevant financial affiliations.

REFERENCES

show all references

1. McMahon EJ, Campbell KL, Bauer JD, Mudge DW. Altered dietary salt intake for people with chronic kidney disease. Cochrane Database Syst Rev. 2015;(2):CD010070....

2. Coresh J, Selvin E, Stevens LA, et al. Prevalence of chronic kidney disease in the United States. JAMA. 2007;298(17):2038–2047.

3. Go AS, Chertow GM, Fan D, McCulloch CE, Hsu CY. Chronic kidney disease and the risks of death, cardiovascular events, and hospitalization [published correction appears in N Engl J Med. 2008;18(4):4]. N Engl J Med. 2004;351(13):1296–1305.

4. Collins AJ, Li S, Gilbertson DT, Liu J, Chen SC, Herzog CA. Chronic kidney disease and cardiovascular disease in the Medicare population. Kidney Int Suppl. 2003;(87):S24–S31.

5. Hunsicker LG. The consequences and costs of chronic kidney disease before ESRD. J Am Soc Nephrol. 2004;15(5):1363–1364.

6. Kotchen TA, Cowley AW Jr, Frohlich ED. Salt in health and disease—a delicate balance. N Engl J Med. 2013;368(13):1229–1237.

7. NKF K/DOQI clinical practice guidelines on hypertension and antihypertensive agents in chronic kidney disease. http://www2.kidney.org/professionals/KDOQI/guidelines_bp/guide_6.htm. Accessed July 12, 2016.

8. Kidney Disease: Improving Global Outcomes (KDIGO) Blood Pressure Work Group. KDIGO clinical practice guideline for the management of blood pressure in chronic kidney disease. Kidney Int Suppl. 2012;2(5):337–414.

These are summaries of reviews from the Cochrane Library.

This series is coordinated by Corey D. Fogleman, MD, Assistant Medical Editor.

A collection of Cochrane for Clinicians published in AFP is available at http://www.aafp.org/afp/cochrane.

 

 

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