Patient characteristics and effects of the long-acting calcium channel blocker barnidipine on circadian blood pressure changes: Results of the Japanese Multicenter Study on Barnidipine with Ambulatory Blood Pressure Monitoring

The results of blood pressure variability patterns in the Japanese Multicenter Study on Barnidipine with Ambulatory Blood Pressure Monitoring (J-MUBA) were analyzed after evaluating daytime and night-time blood pressure levels in 502 hypertensive patients. The patients were divided into the high- (398 patients [79%]) and low-systolic blood pressure (SBP) groups based on 24-h SBP. Patients in the high-SBP group were further subdivided into four groups based on the nocturnal/daytime SBP ratio (nocturnal SBP reduction rate). The inverted dipper group consisted of 53 patients (13%), nondipper group of 116 patients (29%), dipper group of 166 patients (42%), and extreme dipper group of 63 patients (16%). After averaging 24-h SBP, it was found that age, female gender, and a prior history of stroke were independent predictors of inadequate nocturnal SBP reduction. Blood pressure variability patterns were evaluated in 387 hypertensive patients at baseline and after 6 months' administration of barnidipine. Although barnidipine decreased outpatient clinic blood pressure and had hypotensive effects over 24 h, it did not influence heart rate. When the effects of barnidipine on 24-h blood pressure were evaluated after classifying the 387 patients into high- and low-SBP groups, barnidipine adequately controlled blood pressure in the high-SBP group over 24 h, but had less effect on blood pressure in the low-SBP group. In addition, when the effects of barnidipine were evaluated in the high-SBP group based on blood pressure variability pattern, barnidipine similarly decreased daytime and night-time blood pressure in both the inverted dipper and non-dipper groups. However, barnidipine had only weak hypotensive effects in the dipper group during the night-time. In the extreme dipper group, although barnidipine markedly decreased elevated daytime blood pressure, it did not further lower night-time blood pressure.