This trial is located in the United States. It aims to study the effects of aldosterone and drugs that block aldosterone on blood pressure during exercise in patients with hypertension (high blood pressure). The outcome to be measured is the activity of muscle nerves during exercise.
The details
Patients with hypertension often have a large increase in blood pressure during exercise. It is suggested that aldosterone (a hormone in body) contributes to this large increase. By administering drugs that act against aldosterone, it is thought that this increase in blood pressure can be prevented.
Eplerenone (Inspra) is a drug that blocks the effects of aldosterone. It is used to treat hypertension. Amlodipine (Norvasc) is a drug that is used to treat hypertension. It works by widening blood vessels and improving blood flow.
Who are they looking for?
The study will recruit participants for three different groups:
patients with stage I hypertension (140-159/90-99 mmHg)
patients with stage I hypertension and primary aldosteronism (overproduction of aldosterone in the body)
participants with normal blood pressure
Patients will be excluded if they have any evidence of heart or lung disease, blood pressure above 160/100 mmHg, low kidney function or diabetes. Patients must not have any history of substance abuse or currently smoke. Patients must have no history of malignancy (such as cancer).
How will it work
Patients will be randomly assigned to one of two treatment groups. The first group will first receive amlodipine daily for 12 weeks. A series of tests will then be performed. Then, they will receive eplerenone daily for 8 weeks. The same series of tests will be performed.
The second group will first receive eplerenone daily for 12 weeks. Tests will then be performed. They will then receive amlodipine daily for 8 weeks. The same tests will be performed.
These tests of muscle nerve function include measuring activity of nerves using a needle with electrical stimulation and handgrip exercises. Blood flow in the arm will be measured. Heart function, blood pressure and nerve activity will be measured after exercise and after hands are placed in cold water.
