Abstract 9906: Losartan/hydrochlorothiazide Combination was Superior to High-dose Losartan in Controlling Morning Hypertension and Reducing Urinary Albumin Excretion

Abstract

Background: There is little evidence for treatment of morning hypertension, an independent risk for cardiovascular events. Thus, we compared the efficacy of losartan/hydrochlorothiazide combination and high-dose losartan in patients with morning hypertension. Methods: A total of 216 outpatients having hypertension medication were enrolled in a 3-month, prospective, randomized, open-labeled, multicenter trial, when they had systolic blood pressure (SBP) greater than 135 mmHg and/or diastolic blood pressure greater than 85 mmHg in the morning on home blood pressure self-measurement. An antihypertensive drug was randomly switched to a 50-mg losartan/12.5-mg hydrochlorothiazide combination tablet (Combination group, N=109) or 100-mg losartan (High-dose group, N=106). Results: At baseline, SBP levels, clinical background, and biochemical parameters were similar in the two groups. Primary end-point: Morning SBP was reduced by 18 mmHg in Combination group and by 8 mmHg in High-dose group (p<0.001 for both), whereas the resultant levels were lower in Combination group than in High-dose group (P<0.001). Secondary end-points: Urinary albumin excretion (UAE) was reduced in Combination group (P<0.05), but not in High-dose group, although estimated glomerular filtration rates were not changed in either group. Serum uric acid (UA) was decreased in High-dose group (P<0.001), but was not changed in Combination group. %UAE reduction was significantly associated with %morning SBP reduction, UA reduction (negatively), or combination regimen. Multiple linear regression analysis exhibited that %morning SBP reduction was an independent factor associated with %UAE reduction (β=0.277, P<0.05). After adjustments for treatment regimen and UA reduction, %UAE reduction was positively correlated with the tertiles based on morning SBP reduction levels (P=0.02 for trend). Conclusions: Losartan/hydrochlorothiazide combination was more effective than high-dose losartan for controlling morning hypertension and reducing UAE. The reduction in morning SBP was associated with UAE reduction in patients with morning hypertension.