A comparative study on the effectiveness of losartan/hydrochlorothiazide and telmisartan/hydrochlorothiazide in patients with hypertension

Purpose: Long-term effects of a low-dose hydrochlorothiazide (HCTZ) with losartan (LOS) on uric acid (UA) metabolism as well as glucose metabolism have been studied in hypertensive patients in comparison with those of a low-dose HCTZ with telmisartan (TEL).

Method: Fifty-nine hypertensive patients were allocated to a combination therapy with either losartan (50?mg/day)/HCTZ (12.5?mg/day) (LOS?+?HCTZ group: n?=?37) or telmisartan (40?mg/day)/HCTZ (12.5?mg/day) (TEL?+?HCTZ group: n?=?22), respectively. Before and 1 year after the treatment, blood pressure and biochemical parameters of blood and urine were evaluated.

Results: Both systolic and diastolic blood pressures significantly decreased in two groups, without any statistical differences among them. LOS?+?HCTZ caused no changes in the serum UA level or the ratio of UA clearance to creatinine clearance (CUA/Ccr), whereas TEL?+?HCTZ significantly increased the serum UA level and reduced CUA/Ccr. LOS?+?HCTZ did not influence CUA/Ccr in patients with their serum UA below 5.4?mg/dl, while LOS?+?HCTZ significantly increased CUA/Ccr in patients with their serum UA above 5.5?mg/dl. TEL?+?HCTZ significantly reduced CUA/Ccr in patients with their serum UA below and above 5.4?mg/dl to increase serum UA level significantly. Neither combination therapies caused any changes in fasting plasma glucose, HbA1c and HOMA-R. In patients with their serum UA level above 5.4?mg/dl, TEL?+?HCTZ increased HOMA-R, whereas LOS?+?HCTZ did not.

Conclusions: LOS?+?HCTZ did not influence UA metabolism as well as glucose metabolism, likely because of inhibitory action of losartan on URAT1, although TEL?+?HCTZ were accompanied with impairment of the UA metabolism and glucose metabolism.