Sympathetic Mechanisms in Obesity-Crossover Design

Study Overview
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Brief Summary
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We will study obese hypertensive subjects in a randomized, crossover study to determine if two weeks sympathetic blockade improves endogenous glucose production. Subjects will be studied on 3 different occasions after two weeks of receiving either placebo, amlodipine (vasodilator arm) or moxonidine (study arm). The order of the studies will be determined using computer-generated randomization. Patients will be blinded as to which treatment they are receiving on each day. An investigator blinded to the treatment assignment will perform the analysis of the data.

Official Title
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Sympathetic Mechanisms in the Cardiovascular and Metabolic Alterations of Obesity, Crossover Design Study.

Conditions
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Obesity, Hypertension

Intervention / Treatment
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* Drug: Amlodipine
* Drug: Moxonidine
* Drug: Placebo


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Males and females of all races between 18 and 65 years of age Hypertension defined by two or more properly measured seated blood pressure readings >130/85 mmHg or currently on antihypertensive medication. Obesity will be defined as having a body mass index (BMI) ≥ 30 kg/m2. Able and willing to provide informed consent. Exclusion Criteria: Pregnancy or breast feeding Current smokers or history of heavy smoking (>2 packs/day) History of alcohol or drug abuse Previous allergic reaction to study medications Type I diabetes. Cardiovascular disease other than hypertension such as myocardial infarction within 6 months prior to enrollment, presence of angina pectoris, significant arrhythmia, congestive heart failure (LV hypertrophy acceptable), deep vein thrombosis, pulmonary embolism, second or third degree heart block, mitral valve stenosis, aortic stenosis, or hypertrophic cardiomyopathy History of serious cerebrovascular disease such as cerebral hemorrhage, stroke, or transient ischemic attack History or presence of immunological or hematological disorders Impaired renal function Treatment with chronic systemic glucocorticoid therapy (more than 7 consecutive days in 1 month) Treatment with any investigational drug in the 1 month preceding the study Inability to give, or withdraw, informed consent Other factors which in the investigator's opinion would prevent the subject from completing the protocol (i.e., clinically significant abnormalities on clinical, mental examination or laboratory testing or inability to comply with protocol, inability to find IV access)

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 65 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Basic Science
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Placebo Comparator: Placebo<br>Subjects will received 2 weeks of capsules containing placebo. | Drug: Placebo<br>* Placebo<br>|
| Active Comparator: Amlodipine<br>Subjects will received 2 weeks of capsules containing amlodipine. | Drug: Amlodipine<br>* Subjects will receive either an antihypertensive (amlodipine or moxonidine) medication or placebo for two weeks, then cross over to the second arm, and then after 2 weeks of the second drug/placebo, will be switched to the third arm.<br>* Other names: Antihypertensive;|
| Experimental: Moxonidine<br>Subjects will received 2 weeks of capsules containing moxonidine. | Drug: Moxonidine<br>* Moxonidine<br>* Other names: Antihypertensive;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Endogenous glucose production | Rate of appearance and disappearance of labeled glucose | During two-step insulin clamp (six hours) |