Sympathetic Mechanisms in Obesity-Crossover Design

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

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.

Study Overview

• Status: Recruiting
• Conditions: Hypertension; Obesity
• Intervention / Treatment: Drug: Placebo; Drug: Amlodipine; Drug: Moxonidine

• Study Type: Interventional
• Enrollment (Estimated): 12
• Phase: Phase 2; Phase 1

Contacts and Locations

Study Locations

• United States
  • Tennessee
    • Nashville, Tennessee, United States, 37232
      • Recruiting
      • Vanderbilt University Medical Center
      • Contact: Cynthia Laws, MS; Phone Number: 615-421-1994; Email: autonomicgroup@vumc.org
      • Contact: Alfredo Gamboa, MD; Email: alfredo.gamboa@vumc.org
      • Sub-Investigator: Italo Biaggioni, MD

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 65 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No

Description

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)

Study Plan

How is the study designed?

Design Details

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

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Placebo Comparator: Placebo; Subjects will received 2 weeks of capsules containing placebo.	Drug: Placebo; Placebo
Active Comparator: Amlodipine; Subjects will received 2 weeks of capsules containing amlodipine.	Drug: Amlodipine; 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.; Other Names: Antihypertensive
Experimental: Moxonidine; Subjects will received 2 weeks of capsules containing moxonidine.	Drug: Moxonidine; Moxonidine; Other Names: Antihypertensive

What is the study measuring?

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)

Collaborators and Investigators

• Sponsor: Vanderbilt University Medical Center

Study record dates

Study Major Dates

• Study Start (Actual): May 20, 2022
• Primary Completion (Estimated): December 31, 2028
• Study Completion (Estimated): December 31, 2030

Study Registration Dates

• First Submitted: March 28, 2022
• First Submitted That Met QC Criteria: April 5, 2022
• First Posted (Actual): April 6, 2022

Study Record Updates

• Last Update Posted (Actual): February 27, 2026
• Last Update Submitted That Met QC Criteria: February 26, 2026
• Last Verified: February 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Vascular Diseases; Cardiovascular Diseases; Nutrition Disorders; Overnutrition; Body Weight; Overweight; Pathological Conditions, Signs and Symptoms; Nutritional and Metabolic Diseases; Signs and Symptoms; Obesity; Hypertension; Pyridines; Heterocyclic Compounds, 1-Ring; Heterocyclic Compounds; Pharmacologic Actions; Chemical Actions and Uses; Therapeutic Uses; Cardiovascular Agents; Dihydropyridines; Antihypertensive Agents; Amlodipine; moxonidine
• Other Study ID Numbers: 212413

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: Yes
• Studies a U.S. FDA-regulated device product: No