Comparison between High-dose Telmisartan and Fixed dose Combination of Telmisartan and Hydrochlorothiazide in Patients with Hypertension

We compared treatment with a high-dose angiotensin II receptor blocker(ARB)and combination of ARB with a thiazide diuretic in 17 patients with hypertension. A randomized crossover study was performed giving 80 mg telmisartan or fixed-dose combination of 40 mg telmisartan and 12.5 mg hydrochlorothiazide for 16 weeks each. Although the clinic blood pressure was comparable between the high-dose ARB period(134/81 mmHg)and the combination period(134/82 mmHg), the morning home blood pressure was lower in the combination period than in the high-dose ARB period(138/82 vs. 151/88 mmHg, p=0.026/0.013). No significant difference was observed in urinary albumin excretion, but estimated glomerular filtration rate was lower in the combination than in the high-dose ARB period(58.9 vs. 62.1 mL/min/1.73 m^2, p=0.039). Serum uric acid was higher in the combination than in the high-dose ARB period(6.7 vs. 5.9 mg/dL p=0.022). The indices of glucose metabolism, serum lipids, oxidative stress, inflammation and adipocytokine did not significantly differ between the two periods. There was no significant difference in the measurement of endothelium-dependent vasodilation between the two periods. It is suggested that the addition of thiazide diuretic to medium-dose ARB is more effective in lengthening the hypotensive effect than high-dose ARB, however, care should be taken for the elevation of serum uric acid and the decrease in renal function