A weight loss diet reduced diastolic blood pressure by 12.4 mm Hg in patients in the highest baseline renin index quartile compared with 4.4 mm Hg in the lowest quartile (P=0.009).
RCT (n=593)
Randomized
Yes
Does baseline plasma renin activity predict the diastolic blood pressure response to nonpharmacologic and pharmacologic therapy in patients with mild hypertension?
Baseline plasma renin index significantly predicts the diastolic blood pressure response to both nonpharmacologic (weight loss, low sodium/high potassium diet) and pharmacologic (atenolol, chlorthalidone) therapies in mild hypertension.
OBJECTIVE: Plasma renin activity was measured at baseline and 6 months in a trial of nonpharmacologic therapy of mild hypertension to determine whether plasma renin activity predicts the diastolic blood pressure (DBP) response to nonpharmacologic therapy. DESIGN, SETTING, AND PARTICIPANTS: Randomized controlled trial of volunteers from the general community with mild hypertension (DBP between 90 and 100 mm Hg), off all antihypertensive therapy at baseline, treated in special research clinics (n = 593). INTERVENTIONS: Subjects were randomly assigned to usual, weight loss, or low sodium/high potassium diet and then randomly assigned to receive placebo, chlorthalidone, or atenolol. MAIN OUTCOME MEASURES: Renin was analyzed as plasma renin activity and as a renin index (logarithm of 24-hour urinary sodium excretion times logarithm of plasma renin activity) (593 patients at baseline and 6 months) to correct for varied sodium intakes. The DBP was measured using the random zero device. RESULTS: Change in DBP at 6 months could be predicted from baseline plasma renin activity or renin index. The DBP was decreased after 6 months of therapy by 2 mm Hg for each unit increase in baseline plasma renin activity and by 0.16 mm Hg for each unit increase in baseline renin index. Patients in the highest renin index quartile had a greater DBP response to atenolol therapy, and patients in the lowest renin index quartile had a greater DBP response to chlorthalidone therapy. Weight loss diet achieved a greater reduction in DBP in patients with higher baseline renin index and had an additive effect on DBP response in both of the drug groups. Patients on a weight loss diet receiving placebo in the highest baseline renin index quartile had a reduction in DBP of 12.4 mm Hg, compared with 4.4 mm Hg in the lowest baseline renin index quartile (P = .009). A low sodium/high potassium diet had a lesser effect than a weight loss diet on pharmacologic therapy. As with the weight loss diet, patients on a low sodium/high potassium diet in the highest baseline renin index quartile had a greater reduction in DBP than patients in the lowest baseline renin index quartile. CONCLUSIONS: These data suggest a significant relationship between baseline levels of plasma renin index and the likelihood of success of nonpharmacologic treatment of hypertension.
M. Donald Blaufox (Wed,) conducted a rct in Mild hypertension (n=593). Weight loss or low sodium/high potassium diet, plus chlorthalidone or atenolol vs. Usual diet and placebo was evaluated on Change in diastolic blood pressure at 6 months. A weight loss diet reduced diastolic blood pressure by 12.4 mm Hg in patients in the highest baseline renin index quartile compared with 4.4 mm Hg in the lowest quartile (P=0.009).