What is the feasibility of implementing effective sodium reduction strategies to treat hypertension in primary care settings? A systematic review

Objective: To evaluate whether efficacious counseling methods on sodium restriction can be successfully incorporated into primary care models for the management of hypertension. Methods: We searched MEDLINE, Embase, Cochrane Central Register of Controlled Trials, Database of Abstracts of Reviews of Effects and Health Technology Assessment to identify randomized controlled trials of dietary counseling for salt intake reduction that reported significant reduction in 24-h urinary sodium and blood pressure levels among adults with untreated hypertension. Data extraction and assessment of reproducibility and feasibility were done in duplicate and any disagreements were resolved by consensus. Results: Six trials were included for assessment of methods as they were efficacious in reducing sodium intake (24-h urinary sodium excretion) by 73 to 93 mmol/day (intervention) vs. 3.2 to 12.5 mmol/day (control). This was paralleled with a reduction in blood pressure (-4 to -27 mmHg) between groups. In four of the six trials, the methods were described in sufficient detail to be reproducible, but in none of these trials were the `counseling methods' feasible for application in primary care settings. Apart from multiple sessions of counseling, the reported interventions were supplemented with provision of prepared food, community cooking classes, and intensive inpatient training sessions. Conclusion: Despite the availability of efficacious counseling methods for the reduction of sodium intake among newly diagnosed hypertensive patients (feasible within a clinical trial setting), none of these methods, in their present form, are suitable for incorporation into existing primary care settings in countries such as Canada, United States, and UK.