Combination of antihypertensive therapy in the elderly, multicenter investigation (CAMUI) trial

OBJECTIVE: Combination therapy with angiotensin receptor blockers (ARBs) and calcium channel blockers or diuretics is common for hypertensive patients. This study aimed to determine which combination is better for elderly hypertensive patients. METHODS: In this prospective, randomized, open-label trial, hypertensive outpatients aged at least 65 years who had not achieved their target blood pressure (BP) with standard ARB dosages were randomly assigned to receive either a fixed-dose combination of losartan (50 mg) and hydrochlorothiazide (12.5 mg) (ARB+D; n = 72) or a combination of amlodipine (5 mg) and the typical dosage of ARBs (ARB+C; n = 68) to evaluate the change in the BP, laboratory values and cognitive function. RESULTS: At 3 months, the SBP/DBP was found to have significantly decreased from 156/83 ± 15/11 mmHg to 139/76 ± 14/10 mmHg in the ARB+D group and 155/83 ± 11/10 mmHg to 132/72 ± 14/10 mmHg in the ARB+C group. The BP reduction efficacy was greater in the ARB+C group than in the ARB+D group. At 6 months, the SBP/DBP reached the same level in both groups. At 12 months, the urine albumin/creatinine ratio was significantly decreased from the geometric mean of 17.1 to 9.6 mg/g in the ARB+D group, whereas it was increased from 19.8 to 23.7 mg/g in the ARB+C group. Conversely, the estimated glomerular filtration rate tended to show a decrease in the ARB+D group. There was no significant difference in mini-mental state examination after 1 year. CONCLUSION: ARB+amlodipine (5 mg) yielded a greater BP reduction, whereas ARB+HCTZ (12.5 mg) resulted in a greater reduction in the albuminuria, suggesting that each combination therapy is advantageous in a different manner for elderly hypertensive patients.