Recruiting
Phase 1

Observational Study

Sponsor:

University of Kansas Medical Center

Code:

NCT04934228

Conditions

Blood Pressure

Diabetes

Obesity

Insulin Resistance

Diuretics Drug Reactions

Eligibility Criteria

Sex: All

Age: 18 - 70+

Healthy Volunteers: Not accepted

Interventions

Hydrochlorothiazide 12.5Mg Tab

Clonidine Pill

Placebo

Study Details

Brief summary:

The purpose of this study is to examine the hypothesize that 4 weeks of sympathetic nerve activity (SNA) inhibition (oral clonidine) will cause a significant reduction in circulating blood concentrations and endothelial cell expression of inflammatory markers (e.g., TNF-α, IL-6).

Our study is a prospective study using a randomized, double-blinded design to test 4 weeks of SNA blockade (oral clonidine) compared with a BP-lowering control condition (diuretic, hydrochlorothiazide) or a placebo.

Conditions

Blood Pressure

Diabetes

Obesity

Insulin Resistance

Diuretics Drug Reactions

Study ID

NCT04934228

Start date

Jul 1, 2021

Status verified date

Jun, 2025

Completion date

Aug 1, 2027

Anticipated

Primary completion date

Aug 1, 2026

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 18 - 70+

Healthy Volunteers: Not accepted

Inclusion Criteria:

  • Male or Female, age 18-79
  • Obese: BMI > 30 m/kg2
  • Hypertensive: blood pressure >130/80
  • Elevated insulin resistance (HOMA-IR > 2.5)
  • Waist circ: >102 cm (men) and >88 cm (women)
  • Fasting glucose < 126 mg/dL
  • Fasting triglycerides < 250 mg/dL
  • HbA1c < 6.5%
  • Willing to visit research lab (Fairway CTSU)
  • Willing to undergo a blood draw
  • Able to provide written informed consent

Exclusion Criteria:

  • Current use of clonidine or beta-blockers
  • Current smoker or History of smoking in the past 3 months.
  • Hyperlipidemia: Fasting triglycerides > 250 mg/dL
  • Currently taking hypertension medication
  • History of heart disease (e.g., myocardial infarction, stent, byass, heart attack, stroke, heart failure, valvular heart disease, cardiomyopathy)
  • History of neurological disorders
  • History of transplant
  • Actively participating in other studies, except for a registry study.

Study Design

Enrollment

60 participants

Anticipated

Allocation

Randomized

Intervention Model

Parallel Assignment

Primary purpose

Other

Interventions and Outcome Measures

Arms

placebo comparator: Placebo

KU Investigational Pharmacy will provide the drug prescription bottle with 35-day supply of placebo to the research coordinator to give to the research participant.

The placebo is an inert substance with no intended medical value and is used as a negative control for comparison with the study drug.

Participants will receive a Placebo Pill; has no active ingredients but is made to look like the study drug.

experimental: Clonidine

KU Investigational Pharmacy will provide the drug prescription bottle with 35-day supply of clonidine to the research coordinator to give to the research participant.

Planned use in this study

1. Condition/disease indication(s): Vascular function and blood flow
2. Subject population: Hypertension
3. Dose(s): 0.1 mg (oral)
4. Administration: Oral
5. Dosing regimen: 0.1 mg twice daily by mouth

experimental: Hydrochlorothiazide (HCTZ)

KU Investigational Pharmacy will provide the drug prescription bottle with 35-day supply of Hydrochlorothiazide to the research coordinator to give to the research participant.

Planned use in this study

1. Condition/disease indication(s): Hypertension
2. Subject population: Hypertension
3. Dose(s): 25 mg/day
4. Administration: Oral
5. Dosing regimen: 12.5 mg twice per day

Interventions

Hydrochlorothiazide 12.5Mg Tab

Will receive 4 week supply (35 days) of Hydrochlorothiazide Pills (12.5 mg twice a day)

Planned use in this study

1. Condition/disease indication(s): Hypertension
2. Subject population: Hypertension
3. Dose(s): 25 mg/day
4. Administration: Oral
5. Dosing regimen: 12.5 mg twice per day

Clonidine Pill

Will receive 4 week supply (35 days) of Clonidine Pills (0.1 mg twice/day)

Planned use in this study

1. Condition/disease indication(s): Vascular function and blood flow
2. Subject population: Hypertension
3. Dose(s): 0.1 mg (oral)
4. Administration: Oral
5. Dosing regimen: 0.1 mg twice daily by mouth

Placebo

Will receive a 4 week supply (35 days) of Placebo Pills; has no active ingredients but is made to look like the study drug.

Primary outcome measure

  • Blood Work: Efficacy of 4-week supply of Clonidine Compared VS 4-week supply of control condition using hydrochlorothiazide (HCTZ) and a separate placebo treatment [ Time Frame: Baseline ]
  • Endothelial Cell Sample: Efficacy of 4-week supply of Clonidine Compared VS 4-week supply of control condition using hydrochlorothiazide (HCTZ) and a separate placebo treatment [ Time Frame: Baseline ]
  • Adipose Tissue Sample: Efficacy of 4-week supply of Clonidine Compared VS 4-week supply of control condition using hydrochlorothiazide (HCTZ) and a separate placebo treatment [ Time Frame: Baseline ]
  • Blood Work: Efficacy of 4-week supply of Clonidine Compared VS 4-week supply of control condition using hydrochlorothiazide (HCTZ) and a separate placebo treatment [ Time Frame: 1 Week ]
  • Blood Work: Efficacy of 4-week supply of Clonidine Compared VS 4-week supply of control condition using hydrochlorothiazide (HCTZ) and a separate placebo treatment [ Time Frame: 2 Week ]
  • Blood Work: Efficacy of 4-week supply of Clonidine Compared VS 4-week supply of control condition using hydrochlorothiazide (HCTZ) and a separate placebo treatment [ Time Frame: 4 Week ]
  • Endothelial Cell Sample: Efficacy of 4-week supply of Clonidine Compared VS 4-week supply of control condition using hydrochlorothiazide (HCTZ) and a separate placebo treatment [ Time Frame: 4 Week ]
  • Adipose Tissue Sample: Efficacy of 4-week supply of Clonidine Compared VS 4-week supply of control condition using hydrochlorothiazide (HCTZ) and a separate placebo treatment [ Time Frame: 4 Week ]

Central Contacts and Locations

Central contacts

Seth W Holwerda, Ph,D

9729223230sholwerda@kumc.edu

Davina A Clonch

9132266009dclonch@kumc.edu

Locations

University of Kansas Medical Center

Recruiting

Kansas City, Kansas, United States, 66103

Contacts

Seth W. W Holwerda

9729223230sholwerda@kumc.edu

More Information

Sponsor

University of Kansas Medical Center

Last update posted

Jun 5, 2025

Last verified

Jun, 2025

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-10. This information was provided to ClinicalTrials.gov by University of Kansas Medical Center on 2025-06-05.