Effects of sodium reduction interventions on home and morning home blood pressure: a systematic review and meta-analysis of randomized controlled trials.

Excessive sodium chloride (salt) intake significantly contributes to hypertension and cardiovascular diseases, and reducing sodium is a cornerstone of non-pharmacological management of hypertension. Although the antihypertensive effects of sodium reduction are well established, most existing evidence is from office blood pressure (BP) measurements, with limited data available on home BP. We conducted a systematic review and meta-analysis of randomized controlled trials (RCTs) to assess the effects of sodium reduction on home BP. We searched PubMed and the Cochrane Library from inception to September 2025 and included 23 RCTs comprising 4110 participants. Sodium reduction significantly reduced home systolic BP (SBP) (mean difference [MD], -3.66 mmHg; 95% confidence interval [CI], -4.86 to -2.45; P < 0.001) and home diastolic BP (MD, -1.40 mmHg; 95% CI, -2.08 to -0.71; P < 0.001). Nine studies that reported morning home BP also showed reduced morning home SBP (MD, -4.06 mmHg; 95% CI, -6.60 to -1.52; P = 0.002). Greater reductions in home SBP were observed in predominantly hypertensive populations than in non-hypertensive populations (P for heterogeneity = 0.003). No significant differences were detected across other predefined subgroups. Sodium reduction interventions were also associated with significant reductions in salt intake, urinary sodium excretion, and the urinary sodium-to-potassium ratio. Quantitative synthesis was not feasible because only a few included studies reported cardiovascular or adverse events. In conclusion, sodium reduction interventions effectively lower home BP, including morning home BP, with a greater impact in hypertensive populations. Thus, reducing sodium is a practical strategy for improving home BP control, particularly in hypertensive populations. This systematic review and meta-analysis of randomized controlled trials showed that sodium reduction interventions significantly lowered home systolic blood pressure (SBP), including morning SBP. No significant differences in BP-lowering effects were detected across various sodium reduction strategies, and digital health approaches may support implementation and adherence. Sodium reduction interventions were also associated with reductions in salt intake, urinary sodium excretion, and the urinary sodium-to-potassium ratio. These findings support major hypertension guidelines, including the Japanese Society of Hypertension Guidelines for managing elevated blood pressure and hypertension 2025 (JSH2025) and the JSH Morning Hypertension Eradication Program Project (Asakatsu BP Action Plan-the Morning Blood Pressure 130 Campaign).