 After randomization, patients will be evaluated monthly at the GPs office, for therapy adjustment, to achieve blood pressure normalization i.e Systolic Blood pressure 140 mmHg, and Diastolic Blood pressure 90 mmHg. In the thiazide arm, if blood pressure normalization is not achieved not even with the maximal dose, it will be possible to add any other classes of antihypertensive drugs. Once blood pressure normalization is achieved, GPs will monitor blood pressure once every 2 months, at the renewal of the drug prescription. Blood pressure values will be stored in the central database. At each visit, GPs will record drug therapy, including concomitant medications, evaluate the compliance to assigned antihypertensive regimen, and monitor and record adverse events by reporting all data in the CRF. After two years from randomization, patients will be checked for blood and urine tests and referred to the Hypertension Specialist Centre for echocardiography, carotid ultrasounds and urine dip-stick. This data will be stored in the central database. 