Effect of dietary sodium restriction on patients receiving antihypertensive medication.

Twenty-four patients receiving medication for moderate to severe hypertension were studied during a six week normal diet and a six week low sodium period. Mean urinary sodium excretion was reduced from 169 +/- 13 to 92 +/- 7 mmol/24 hour yet with the exception of a small reduction in the mean erect systolic blood pressure 140.7 +/- 2.5 to 135.1 +/- 2.6; p less than 0.05) no significant alteration in the patients blood pressure was noted. Urinary potassium excretion and body weight remained unaltered. However, evaluation of the patient data when the patients were grouped into those taking thiazide diuretics (n = 14) and those not taking diuretics (n = 10) revealed a significant reduction in the mean supine systolic and diastolic and erect systolic blood pressure in the thiazide group. Significant changes in blood pressure were not recorded in the non-diuretic group. It is suggested that moderate dietary sodium restriction in combination with thiazide diuretics is of value in the treatment of moderate to severe hypertension.