THE BLUNTING OF THE ANTIPROTEINURIC EFFICACY OF ACE-INHIBITION BY HIGH SODIUM-INTAKE CAN BE RESTORED BY HYDROCHLOROTHIAZIDE

Background. Dietary sodium restriction enhances the antiproteinuric an d blood pressure lowering effect of ACE inhibition. In clinical practi ce, however, long-term compliance to a low-sodium diet may be difficul t to obtain. We therefore investigated whether the blunting of the ant iproteinuric and blood pressure lowering efficacy of ACE inhibition by high sodium intake can be restored by the addition of a diuretic. Pat ients and methods. Seven proteinuric patients with non-diabetic renal disease on chronic ACE inhibition were studied during three consecutiv e 4-week periods: low sodium (50 mmol/day), high sodium (200 mmol/day) and high sodium plus hydrochlorothiazide (50 mg o.i.d.). Results. Dur ing low sodium intake proteinuria was 3.1 (0.7-5.2) g/day, during high sodium intake proteinuria increased to 4.5 (1.6-9.2)g/day (P<0.05). I nterestingly, addition of hydrochlorothiazide again reduced proteinuri a to 2.8 (0.6-5.8)g/day (P<0.05). Mean arterial blood pressure was 89 (84-96), 98 (91-104) and 89 (83-94)mmHg (P<0.05) during the three peri ods, respectively. Conclusion. Addition of hydrochlorothiazide can ove rcome the blunting of the therapeutic efficacy of ACE inhibition on pr oteinuria and blood pressure by a high sodium intake.