(1C) RATIONALE K Lowering salt intake reduces BP in the general population. K In CKD patients with reduced GFR, salt retention is associated with an increase in BP. A relationship between average daily salt intake and BP levels has long been recognized, leading to calls from the World Health Organization (WHO) for salt intake to be restricted to improve BP levels (http://www.who.int/cardiovascular_ Restricting salt intake clearly lowers BP by a moderate amount, as demonstrated in a systematic review of seven trials,53 most of which assessed the impact of restricting salt intake to 4 to 6 g (70 100 mmol). Overall, BP levels were reduced as compared to baseline levels: systolic BP by 4.7 mm Hg (95% CI 2.2 7.2) and diastolic BP by 2.5 mm Hg (95% CI 1.8 3.3). Moderate heterogeneity was observed in the effects on systolic BP, but this was corrected when one outlier trial was excluded. Other systematic reviews including a different group of trials have suggested similar but somewhat smaller benefits.62 Alterations in salt handling are likely to be a significant contributor to elevated BP levels in patients with CKD. Although no large scale long term RCTs of salt restriction in CKD patients were found, there is no reason to believe that BP reductions should not also be observed. Reducing salt intake could have a greater capacity to lower BP in patients with CKD who have salt and water retention and this intervention should be routinely discussed with such individuals. A low-sodium diet has been shown to further reduce BP and urine albumin or protein levels in the short term in patients on ARBs63 66 and may be a consideration for those with high BP who have a poor response to ACE-Is or ARBs. 