Effects of moderate salt restriction in hypertensive patients treated with oxprenolol or chlorthalidone

Ninety-five hypertensive out-patients, whose lying diastolic blood pressure was still greater than or equal to 95 mm Hg after a 4-week treatment with oxprenolol slow release 160 mg/day or chlorthalidone 25 mg/day, restricted their daily sodium intake for a 4-week period, while continuing to receive the previous pharmacological therapy. The dietary intervention, appositely formulated to moderately restrict sodium intake, resulted in a high patient compliance as assessed by the significant (p less than 0.01) reduction in the 24-hour urinary sodium excretion. At the end of the 4-week dietary period, a significant (p less than 0.01) decrease in lying and standing systolic and diastolic blood pressure was observed in both the oxprenolol and chlorthalidone treated groups. These results suggest that a moderate reduction in sodium intake, obtained from a low sodium diet characterized by high patient compliance and easily followed in everyday life, is effective in lowering blood pressure in hypertensive patients who don't respond satisfactorily to pharmacological therapy alone.