Change in blood pressure between visit week 4 and visit week 12. For 24-h-ABPM the respective values of the last day of run-in and the last day of week 12 are compared. For SBPM the mean values 14 days preceding week 4 visit are compared with the 14 days preceding week 12 visit are compared. White bars: change of systolic blood pressure value, black bars: change of diastolic blood pressure value. *: t-test p < 0.05. **:t-test p < 0,01.