Improvement of serum uric acid (SUA) is thought to have a favorable influence on blood pressure (BP) and renal function in hypertensive patients irrespective of diuretic therapy. The effects of switching therapy to a fixed dose combination (FDC) of losartan (LOS) 50 mg with hydrochlorothiazide (HCTZ) 15 mg (LOS/HCTZ) on BP, UA metabolism, and renal function were assessed in hypertensive patients treated with a FDC of telmisartan (TEL) 40 mg with HCTZ 15 mg (TEL/HCTZ) and compared those of a FDC of TEL with amlodipine (AM) 5 mg (TEL/AM).Design and Method:
Sixty-seven hypertensive patients were allocated either LOS/HCTZ (n = 36) or TEL/AM group (n = 31), respectively.Results:
Both LOS/HCTZ and TEL/AM were effective in reducing SUA but caused no change in BP after 12 months. LOS/HCTZ increased percent fractional excretion of UA (FEUA) but caused no change in estimated glomerular filtration rate (eGFR). TEL/AM increased eGFR, but trend for increase in FEUA was not significant. Although UA metabolism improved, urinary albumin/creatinine excretion ratio (UACR) increased in two groups. The increase in UACR of TEL/AM was greater than that of LOS/HCTZ. The change in UACR was positively correlated with the changes in eGFR but not with SUA or FEUA.Conclusions:
The switching therapy equally controlled BP and improved UA metabolism. Although both LOS-induced inhibitory action of urate transporter 1 and deletion of HCTZ-induced plasma volume reduction were associated with improvement of UA metabolism in the patients, it did not support the beneficial effect of SUA lowering therapy on renal protection.