The purpose of this trial is to evaluate if an objective clinical decision of anti-hypertensive therapy can be made using an N-of-1 (single patient) trial design.

Personalized medicine involves choosing the optimal treatment for a patient based on data gathered by the physician that is specific to that individual. The N-of-1 or single patient trial is a study design motivated by the new era of personalized medicine. The Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC 7) recommends a personalized medicine approach to hypertensive drug class choice based on compelling indications. However, the hypertensive decision algorithm is limited. With the advent of new technology the amount of data available to a physician has grown substantially improving the robustness of surveying a more complete picture of the patient's health care status. Medicine is quickly becoming data intensive with new technology decreasing the cost of data collection and analysis.

The typical standard care for patients with stage 1 hypertension first involves a non-pharmacological modification of lifestyle changes. Health care providers diagnose hypertension when the blood pressure is persistently elevated after three to six visits over a several month period. JNC 7 recommends thiazide-type diuretics for Stage I hypertension for most patients. In the United States, this recommendation results in most patients being given a dose of hydrochlorothiazide (HCTZ) at 12.5 to 25 mg per day. A patient would then return for follow-up and would be prescribed a few month supply of an antihypertensive medication (e.g. HCTZ or lisinopril). The choice of treatment by the physician is based on JNC 7 guidelines, patient's risk factors, and a provider's experience.

The objective of this trial will be to evaluate if an objective clinical decision of anti-hypertensive therapy can be made using an N-of-1 (single patient) trial design. In this study we propose to do a series of N-of-1 trials in patients with stage 1 hypertension who will be randomized to alternating courses of HCTZ and lisinopril.

Inclusion Criteria:

• Diagnosis of Grade 1 Hypertension
• Treatment naïve
• GFR > 60 within previous 3 months
• Urinary microalbumin level normal during previous 3 months

Exclusion Criteria:

• Pregnancy (Fetal morbidity and mortality may occur with the use of ACE inhibitors.)
• Uncontrolled Hyperthyroidism
• Sleep Apnea
• Primary Aldosteronism
• Renovascular Disease
• Cushing's Syndrome or steroid therapy
• No evidence of end organ damage
• EKG with evidence of LVH within previous 3 months
• Collagen Vascular Disease
• Current Smoker