Abstract 4425: Baseline Aldosterone/Renin Ratios Predict Responses to Thiazide in Essential Hypertension, Particularly for Already-Treated Patients
Background: Response to diuretics are variable among hypertensive patients. Our study sought to identify patients who respond well to thiazide diuretics.
Methods: Non-diabetic patients with either treated or untreated hypertension were evaluated if their office systolic blood pressure was ≥ 140 mmHg or if their diastolic blood pressure was ≥ 90 mmHg. After 2 weeks of a controlled diet and life style modification, patients who still had an elevated blood pressure (BP) were prospectively given hydrochlorothiazide, 50 mg per day for 2 weeks, in addition to their current treatment if there was any. Variables monitored both before and after treatment included serum aldosterone and renin, office BP.
Results: Sixty-six patients received 2 weeks of thiazide treatment. Of the 66, the 27 (41%) who had a significant reduction (≥ 10% reduction from baseline) in office mean arterial pressure (MAP) were defined as responders. The other 39 patients, those who had a reduction in office MAP of < 10% were defined as non-responders. Responders had a higher aldosterone/renin ratio (ARR) (77.90 ± 94.08 vs. 34.67 ± 45.56, p = 0.009) and a lower renin activity (7.44 ± 12.34 vs. 13.88 ± 14.00 pg/mL, p = 0.004). MAP reductions were directly correlated to ARR and inversely correlated to renin activity. ARR ≥ 18.58 independently predicted BP responses to thiazide in patients already taking other antihypertensive medications.
Conclusions: The ARR is an independent predictor of responders to hydrochlorothiazide in non-diabetic hypertensive patients, particularly in those already taking other antihypertensive medications.