Salt restriction in chronic kidney disease: a simple need or a must?

Dietary salt restriction is one of the most important non pharmacological intervention in the management of hypertension and cardiovascular complications. In Chronic Kidney Disease (CKD) patients, observational and recent interventional studies investigating the relationship between sodium intake and renal outcomes suggest that low salt diet is warranted in this high risk category of patients. Moreover reducing and maintaining a low salt intake in these patients plays a fundamental role for maximizing the beneficial effect of ACE inhibitors on CKD progression. On the other hand, in hypertensive patients there is experimental evidence indicating that a very low sodium diet (<50 mEq/day) generates a pro-inflammatory phenotype characterized by an increase in Procalcitonin and TNF-alpha and a reduction in an anti-inflammatory cytokine like Adiponectin. In this brief review the main mechanisms whereby salt intake may determine kidney damage and studies showing that salt restriction may have a beneficial effect in CKD patients will be discussed.