Treatment with 0.6 mg moxonidine daily in treatment-naïve subjects with mild or moderate hypertension according to guidelines (Stage 1: Systolic Blood Pressure =140-159 mmHg, Diastolic Blood Pressure =90-99 mmHg, and Stage 2: systolic blood pressure=160-179 mmHg, diastolic blood pressure=100-109 mmHg) that require monotherapy and reevaluation after 12 weeks