Inclusion Criteria:  treatment-naïve subjects with mild or moderate hypertension according to Joint National Committee 7 and European Society Hypertension / European Society Cardiology 2008 (Stage 1: Systolic Blood Pressure =140-159 mmHg, Diastolic Blood Pressure =90-99 mmHg, and Stage 2: Systolic=160-179 mmHg, Diastolic=100-109 mmHg) that require monotherapy  Exclusion Criteria:  age beyond 25-75 years, not taking currently anti-hypertensive medication not taking anti-diabetic or lipid lowering medication and other diseases or conditions that may influence blood pressure, heart rate and catecholamines' and Neuropeptide Y levels, including anemia, fever, stage III hypertension, coronary artery disease, recent (less than 6 months) myocardial infraction or stroke, heart failure, secondary hypertension, diabetes mellitus, abnormal thyroid status or other obesity-related endocrinopathies, pregnancy, kidney failure, alcohol abuse, malignancies, depression or other psychiatric illnesses, such as schizophrenia,