3. All patients must be diagnosed as having hypertension: For this project, hypertension will be defined according to the widely accepted criteria of the 6th Joint National Committee (JNC VI) Guidelines on Prevention, Detection, Evaluation and Treatment of Hypertension, which is a systolic blood pressure > 140 mm hg or a diastolic blood pressure > 90 mm hg or if participants are taking any prescribed antihypertensive medication.