Effect of sodium restriction on blood pressure of unstable or uncontrolled hypertensive patients in primary care

BACKGROUND/OBJECTIVES: The aims of the present study are: 1) to quantify sodium consumption of patients with unstable or uncontrolled hypertension, 2) to investigate if reduced sodium intake can lower BP in these patients, and 3), to assess the acceptability and feasibility of this approach. SUBJECTS/METHODS: This study included 25 adults (age: 50+ years) with frequently elevated BP or patients with uncontrolled, uncomplicated hypertension despite drug treatment in a general practice setting. BP and salt intake (24h urinary excretion and food records) were measured at baseline and after a sodium reduced diet. RESULTS: Mean (${\pm}SD$) systolic (SBP) over diastolic (DBP) blood pressure (mmHg) at baseline was $150.7({\pm}9.5)$/$84.149({\pm}5.6)$. Mean urinary sodium excretion was 146 mmol/24h. A reduction of 28 mmol sodium excretion decreased SBP/DBP to $135.5({\pm}13.0)$/$82.5({\pm}12.8)$ (P < 0.001). After one month of no dietary advice, only in 48%, SBP was still ${\leq}140mmHg$. CONCLUSION: Assessment of sodium intake using food records, 24h urine collections and probing questions to identify use of sodium containing supplements or drugs are essential for tailored advice targeted at sodium intake reduction. The results of the present study indicate that reduced sodium intake can lower BP after 4 weeks in unstable or uncontrolled hypertensive patients.