Background: Angiotensin II receptor blocker (ARB) as a first-line drug for hypertension in diabetes often fails to control blood pressure adequately. The objective of the study was to evaluate the effect of amlodipine combined therapy on home blood pressure (HBP) useful for management of hypertension.
Methods and results: A total of 263 type 2 diabetes with hypertension refractory to standard dose of ARB were randomized to increased ARB regimen (n=132) or amlodipine combination regimen (n=131). The primary endpoint was change in morning HBP at 1 year. The combination regimen significantly lowered morning HBP than the increased ARB regimen (158.2/82.5 mmHg in the combination regimen, 157.3/84.4 mmHg in the increased ARB regimen, at baseline; 142.7/76.3 vs. 155.0/83.1 mmHg, respectively, P<0.001 for both, at 8 weeks; 139.6/74.6 vs. 149.1/78.1 mmHg, respectively, P<0.001 for systolic and P=0.010 for diastolic, at 1 year). The combination regimen showed significantly higher rates of achieving target morning HBP at 8 weeks (11.3% vs. 2.7%, P=0.015). In the combination regimen, estimated glomerular filtration rate declined slower, and carotid intima-media thickness decreased in contrast to the increased ARB regimen.
Conclusions: In type 2 diabetes patients with hypertension refractory to standard dose of ARB, the amlodipine combination regimen provides superior antihypertensive effect on HBP to the increased ARB regimen, and beneficial effects on reducing risks of cardiovascular events.