Telmisartan and hydrochlorothiazide antihypertensive treatment in high sodium intake population: a randomized double-blind trial.

OBJECTIVES: To compare the blood pressure (BP)-lowering effects of telmisartan 40 mg/day and hydrochlorothiazide (HCTZ) 25 mg/day in high sodium intake patients with mild-to-moderate hypertension in China.

METHODS: In this randomized, double-blind trial, eligible patients were randomly divided into telmisartan and HCTZ groups with three follow-ups scheduled on days 15, 30, and 60 after enrollment to compare BP decrease, hypokalemia, and other adverse events after intervention.

RESULTS: A total of 1333 mild-to-moderate hypertensive patients with average sodium intake of 5909 mg/day were enrolled from 14 county hospitals in China. Baseline characteristics were well balanced. At 15, 30, and 60 days of follow-up, average SBP/DBP reduction in telmisartan and HCTZ group was 12.5/8.0, 14.3/9.1, 12.8/7.2, 11.0/5.8, 13.6/7.1, and 11.5/5.3 mmHg, respectively. Telmisartan showed greater BP response than HCTZ at three visits, with statistical significance for DBP (P < 0.001) regardless of the adjustment for baseline BP, sodium excretion, and pulse pressure (PP). SBP reduction was positively related to increasing urinary sodium and PP levels for patients in both groups but increased faster with increasing PP in HCTZ than in telmisartan (P = 0.0238 for group × PP). Compared with telmisartan, HCTZ showed more hypokalemia (0.4 vs. 4.5%, P < 0.001).

CONCLUSION: Both telmisartan and HCTZ were effective for the treatment of hypertensive patients with high sodium intake. Telmisartan showed better DBP-lowering effect and less hypokalemia than HCTZ among high sodium intake patients. Further studies are needed to evaluate the plausible superiority effect of hydrochlorothiazide among patients with large PP.