[Chronic effects of low-dose hydrochlorothiazide in patients with mild to moderate essential hypertension]

To investigate the chronic efficacy of low-dose hydrochlorothiazide (HCTZ) in patients with mild-to-moderate hypertension.

After a 2-weeks placebo run-in period, 232 patients with mild or moderate hypertension were recruited and received HCTZ (12.5 mg once daily) therapy for one year. Patient compliance and blood pressure were monitored and serum BUN, Cr, glucose, electrolytes, and lipids were measured before, 6 weeks and 1 year after treatment.

(1) Reduction of SBP, DBP and MAP were more significantly at 1 year [(10.45 +/- 17.28) mm Hg, (8.45 +/- 11.06) mm Hg, (9.12 +/- 10.88) mm Hg] than that at 6 weeks post therapy [(6.01 +/- 16.05) mm Hg, (2.90 +/- 10.33) mm Hg, (3.94 +/- 10.68) mm Hg, all P < 0.05]. Blood pressure were reduced to normal in 35.1% patients at 1 year and in 20.3% patients at 6 weeks (P < 0.05). (2) No patient developed diabetes mellitus or hypokalemia during therapy while the serum uric acid at 1 year post therapy was significantly higher than that at before therapy (P < 0.05).

The study indicates that low dose HCTZ is an effective and safe antihypertensive agent for patients with mild-to-moderate hypertension and uric acid changes during therapy need to be monitored.