A dietary sodium reduction of 40 mmol/day decreased mean systolic blood pressure by 4.5 mmHg in patients with chronic kidney disease.
Meta-Analysis (n=1,759)
Yes
Does dietary sodium reduction reduce blood pressure in patients with chronic kidney disease and/or hypertension?
Dietary sodium reduction demonstrates a linear dose-response relationship with blood pressure reduction, with the most pronounced antihypertensive effects seen in patients with chronic kidney disease.
Effect estimate: Mean difference -4.5 mmHg (95% CI -5.8, -3.1)
Background: Hypertension (HTN) is a leading risk factor for cardiovascular disease, and dietary sodium reduction is a cornerstone strategy for blood pressure (BP) control, particularly in vulnerable populations such as individuals with chronic kidney disease (CKD), who often present with HTN. This study aims to quantify the dose-response relationship between changes in sodium intake and changes in BP, through a meta-analysis of recent randomized controlled trials (RCTs) in individuals with CKD and with or without HTN. Methods: A systematic literature search was conducted in PubMed, Cochrane Central and Embase databases to identify RCTs published since 2000 that evaluated the isolated effect of sodium intake modification on systolic and diastolic. Only trials estimating sodium intake via 24-h urinary sodium excretion were included to ensure accurate measurement of dietary intervention. A random-effects model was used to pool effect sizes, accounting for between-study heterogeneity. Linear, quadratic and cubic dose-response models were fitted and compared with identify the best-fitting relationship between sodium change and BP change. Results: The analysis included 43 RCTs with 51 distinct population groups, involving 1759 subjects. The linear model best described the dose-response relationship in subjects with CKD, with or without HTN. A reduction in sodium intake of 40 mmol/day (approximately 2.4 g of salt) was associated with a mean systolic BP/diastolic BP reduction of -4.5 mmHg (95% confidence interval -5.8, -3.1)/-2.2 mmHg (-3.0, -1.3) in patients with CKD, -2.3 mmHg (-3.0, -1.6)/-1.1 mmHg (-1.5, -0.6) in patients with HTN and -0.3 mmHg (-0.5, -0.1)/-0.1 mmHg (-0.2, -0.1) in patients without HTN. Conclusion: Reducing sodium intake has a pronounced antihypertensive effect in patients with CKD and/or HTN. Regardless of the variability in effect according to BP status, adopting a low-salt diet represents good clinical practice and should be considered a standard prescription, particularly for individuals with CKD, as it supports better BP control and helps reduce cardiovascular risk.
Iwelomene et al. (2025) conducted a meta-analysis in Hypertension and Chronic Kidney Disease (n=1,759). Dietary sodium reduction vs. High sodium intake was evaluated on Mean change in systolic blood pressure in patients with chronic kidney disease (Mean difference -4.5 mmHg, 95% CI -5.8, -3.1). A dietary sodium reduction of 40 mmol/day decreased mean systolic blood pressure by 4.5 mmHg in patients with chronic kidney disease.