Sodium Intake and Renal Outcomes: A Systematic Review

BACKGROUND: Sodium intake is an important determinant of blood pressure; therefore, reduction of intake may be an attractive population-based target for chronic kidney disease (CKD) prevention. Most guidelines recommend sodium intake of < 2.3 g/day, based on limited evidence. We reviewed the association between sodium intake and renal outcomes. METHODS: We reviewed cohort studies and clinical trials, which were retrieved by searching electronic databases, that evaluated the association between sodium intake/excretion and measures of renal function, proteinuria, or new need for dialysis. RESULTS: Of 4,337 reviewed citations, seven (n = 8,129) were eligible, including six cohort studies (n = 7,942) and one clinical trial (n = 187). Four studies (n = 1,787) included patients with CKD. All four cohort studies reported that high intake (> 4.6 g/day) was associated with adverse outcomes (vs. moderate/low), while none reported an increased risk with moderate intake (vs. low). Three studies (n = 6,342) included patients without CKD. Two cohort …