Blood Pressure-Lowering Medications, Sodium Reduction, and Blood Pressure.

Background: Both blood pressure-lowering medication and sodium reduction are effective in hypertension control, but whether the effect of sodium reduction differ across blood pressure-lowering medications is unclear. This study aims to evaluate the dose-response effect of sodium intake reduction on blood pressure in treated hypertensive individuals and the impact of different classes of blood pressure-lowering drugs.
Methods: We searched multiple databases and reference lists up to July 9, 2024. Randomized controlled trials with a duration of ≥2 weeks comparing the effect of different levels of sodium intake (measured by 24-hour urinary sodium excretion) on blood pressure in hypertensive individuals treated with constant blood pressure-lowering medications were included. Instrumental variable meta-analyses based on random-effects models were conducted to evaluate the dose effect of sodium reduction on blood pressure. Subgroup analyses were performed based on the class of blood pressure-lowering drugs, age, baseline sodium and blood pressure levels, and study duration.
Results: We included 35 studies (median duration of 28 days) with a total of 2885 participants. For every 100 mmol reduction in 24-hour urinary sodium excretion, systolic blood pressure decreased by 6.81 mm Hg (95% CI, 4.96-8.66), diastolic blood pressure decreased by 3.85 mm Hg (95% CI, 2.26-5.43), and mean arterial pressure decreased by 4.83 mm Hg (95% CI, 3.22-6.44). The dose-response effects varied across classes of blood pressure-lowering medications, with greater effects observed in the β-blockers, renin-angiotensin-aldosterone system inhibitors, and dual therapy groups. No significant subgroup differences were observed across subgroups defined by age, baseline 24-hour urinary sodium excretion, blood pressure levels, or study duration.
Conclusions: Pooled evidence suggests a dose-response relationship between sodium reduction and blood pressure in treated individuals with hypertension, influenced by the class of blood pressure-lowering medications.
Competing Interests: G.A. MacGregor is the unpaid Chair of Consensus Action on Salt, Sugar and Health (CASSH), World Action on Salt, Sugar and Health (WASSH) and Blood Pressure UK. F.J. He is an unpaid member of CASSH and WASSH. S. Pombo-Rodrigues is the campaign lead for CASSH. The other authors report no conflicts.