Effect of "no added salt diet" on blood pressure control and 24 hour urinary sodium excretion in mild to moderate hypertension

BACKGROUND: The incidence of Hypertension as a major cardiovascular threat is increasing. The best known diet for hypertensives is 'no added salt diet'. In this study we evaluated the effect of 'no added salt diet' on a hypertensive population with high dietary sodium intake by measuring 24 hour urinary sodium excretion. METHODS: In this single center randomized study 80 patients (60 cases and 20 controls) not on any drug therapy for hypertension with mild to moderate hypertension were enrolled. 24 hour holter monitoring of BP and 24 hour urinary sodium excretion were measured before and after 6 weeks of 'no added salt diet'. RESULTS: There was no statistically significant difference between age, weight, sex, Hyperlipidemia, family history of hypertension, mean systolic and diastolic BP during the day and at night and mean urinary sodium excretion in 24 hour urine of case and control groups. Seventy eight percent of all patients had moderate to high salt intake. After 6 week of 'no added salt diet' systolic and diastolic BP significantly decreased during the day (mean decrease: 12.1/6.8 mmhg) and at night (mean decrease: 11.1/5.9 mmhg) which is statistically significant in comparison to control group (P 0.001 and 0.01). Urinary sodium excretion of 24 hour urine decreased by 37.1 meq/d +/- 39,67 mg/dl in case group which is statistically significant in comparison to control group (p: 0.001). Only 36% of the patients, after no added salt diet, reached the pretreatment goal of 24 hour urinary sodium excretion of below 100 meq/dl (P:0.001). CONCLUSION: Despite modest effect on dietary sodium restriction, no added salt diet significantly decreased systolic and diastolic BP and so it should be advised to every hypertensive patient. TRIAL REGISTRATION: Clinicaltrial.govnumber NCT00491881.