Abstract
We previously reported in untreated hypertensive patients that 24 hour urinary sodium excretion correlated with diastolic pressure (r=0.52, p= 0.0003) and ambulatory diastolic pressure (r=0.53, p=0.01). We therefore investigated the effect of a diet low in sodium on blood pressure.
Methods: Thirty-six patients (M:F, 18:18; age 45±12 yrs) with untreated mild essential hypertension were randomised to drug treatment (hydrochlorothiazide 25 mg daily [n=12] or metoprolol 100 mg daily [n=8]) or non-pharmacological treatment (n=16) for 6 months. Ambulatory blood pressure measurements were performed.
There was a significant decrease in ambulatory systolic and diastolic blood pressure in the drug treatment (19±3 mmHg and 11±2 mmHg) and diet group (10±2 mmHg and 6±1 mmHg). In the non-pharmacological group, the decrease in sodium intake correlated with the decrease in systolic (r=0.78, p=0.001) and diastolic blood pressure (r=0.78, p=0.001). Overall, the change in sodium excretion also correlated with systolic blood pressure (r=0.49, p=0.003) and diastolic blood pressure (r=0.44, p=0.01)(fig.).
Blood pressure reduction is related to the reduction in sodium intake. Those hypertensive patients who can reduce salt intake will have a decreased blood pressure.
