 8. Follow up: All patients should give written informed consent at entry into the present study. In addition to 24-h ambulatory blood pressure monitoring, patients should also undergo a questionnaire survey and clinical measurements including clinic blood pressure. Patients should be followed up in normal working hours in the morning or in the afternoon. The precise follow-up time of the day should be recorded. At each follow-up visit, the responsible physician should measure a patients blood pressure and pulse rate, and collect information on the use of medications, serious adverse events, adverse events and cardiovascular complications. At 4 and 8 weeks of follow-up, 24-h and 48-h ambulatory blood pressure monitoring will be performed, respectively. When 48-h ambulatory blood pressure monitoring is performed at 8 weeks of follow-up, the patient should not take any antihypertensive medication on the second day of monitoring. 