Vascular Dysfunction in Human Obesity Hypertension: Integrative Role of Sympathetic and Renin-Angiotensin Systems (VANISH study)
The purpose of the study is to test the effects of blocking sympathetic nerve activity with a drug called clonidine on blood vessel function and muscle nerve activity in adults who are obese and have high blood pressure.
The cohort of subjects will consist of 69 healthy young men and women age 18-79 years who are obese, defined as a body mass index \> or = to 30 kg/m2, who have untreated systolic hypertension (systolic blood pressure \> or = to 130 - \<180 mmHg- average of at least 3 measurements 2 min apart after 10 min seated resting position). These 69 subjects will then be randomized to 3 treatment arms: clonidine (0.1 mg/day), hydrochlorothiazide (25 mg/day) or placebo for 4 weeks in years 1 and 2. All tablets will be encapsulated by to look identical. Subjects will randomly (1:1:1) receive one of the following combinations in a double-blind, placebo-controlled design:
1. Oral clonidine (0.1 mg twice/day)
2. Oral hydrochlorothiazide (12.5 mg twice/day)
3. Oral placebo
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