HypertensionPhase 1/2NCT04715022
Sympathetic-vascular Dysfunction in Obesity and Insulin Resistance (Vitamin C Study)
A Phase 1/2 study testing Ascorbic acid solution (American Regent Laboratories Inc.) and Saline in people with Hypertension and Cardiovascular Diseases, run by University of Kansas Medical Center at 1 site in United States.
Trial summary
The main purpose of research is to examine and understanding the development of hypertension in obese adults with insulin resistance. Findings from our studies will identify unique mechanisms that can be targeted to limit increases in vascular dysfunction and reduce the excessively high prevalence of hypertension and… Read more about this study
- Who is it for?
- Ages 35 to 65 years
- Conditions the study is for
- Hypertension, Cardiovascular Diseases
- What is being tested?
- Ascorbic acid solution (American Regent Laboratories Inc.) and Saline
- Type of treatment
- Injection or infusion
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 23 participants
- Where
- 1 siteUnited States
- Study dates
- 17 Jun 2021to 1 Aug 2027
- Phase
- Phase 1/2
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 35 to 65 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Obese: BMI >30 m/kg2
- Middle-aged: 35-65 years
- Participants must be willing and able to discontinue taking any vitamin C or E supplements or omega-3 fatty acids beginning 2 weeks prior.
- Able and willing to provide written informed consent
Who cannot join
- Diabetes mellitus: fasting glucose < 1267 mg/dL and/or HbA1c < 6.5%
- Currently taking a statin or antihypertension medication
- Hyperlipidemia: Fasting triglycerides < 250 mg/dL
- Hypertension: <130/80 mmHg
- History of heart disease (e.g., myocardial infarction, stent)
- History of vascular disease (e.g., bypass, stroke)
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
United States1 site, 1 recruiting
- Recruiting
University of Kansas Medical Center
Kansas City, Kansas, 66160
Davina Clonch, 913-226-6009, dclonch@kumc.edu
Megan Gangwish, 913-444-0949, mgangwish@kumc.edu
About this study
Official title: Sympathetic-vascular Dysfunction in Obesity and Insulin Resistance
The main purpose of research is to examine and understanding the development of hypertension in obese adults with insulin resistance. Findings from our studies will identify unique mechanisms that can be targeted to limit increases in vascular dysfunction and reduce the excessively high prevalence of hypertension and risk for cardiovascular disease (CVD).
This study is testing the health of the blood vessels and the activity of the nerves that control the blood vessels in adults with insulin resistance. The extent to which ascorbic acid (Vitamin C) improves the function of the blood vessels will be determined. The primary outcome is blood pressure, which is the result of blood vessel health and activity of the nerves, and the reduction in blood pressure that is observed with ascorbic acid.
- Conditions
- Hypertension, Cardiovascular Diseases
- Being tested
- Ascorbic acid solution (American Regent Laboratories Inc.), Saline
- Medical subject headings
- Hypertension, Cardiovascular Diseases
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Ascorbic acid solution (American Regent Laboratories Inc.)Drug
Ascorbic acid solution (American Regent Laboratories Inc.) will be obtained from the KU Investigational Pharmacy located in the KU Clinical Research Center where studies will take place. A priming bolus of 0.06 g ascorbic acid/kg fat free mass (FFM) dissolved in 100 mL of saline will be infused intravenously at 5 mL/min for 20 minutes, followed immediately by a "drip-infusion" of 0.02 g/kg FFM dissolved in 30 mL of saline administered over 2 hours at 0.5 mL/min.
SalineDrug
Placebo (saline) will be administered
| Study group | Role | What they receive |
|---|---|---|
| Placebo infusion | Placebo comparator | Saline will be administered over 2 hours Receives: Drug: Saline |
| Ascorbic acid infusion | Active comparator | Ascorbic acid solution (American Regent Laboratories Inc.) will be obtained from the KU Investigational Pharmacy located in the University of Kansas (KU) Clinical Research Center where studies will take place. A priming bolus of 0.06 g ascorbic acid/kg fat free mass (FFM) dissolved in 100 mL of saline will be infused intravenously at 5 mL/min for 20 minutes, followed immediately by a "drip-infusion" of 0.02 g/kg FFM dissolved in 30 mL of saline administered over 2 hours at 0.5 mL/min. Receives: Drug: Ascorbic acid solution (American Regent Laboratories Inc.) |
What is being measured
The primary outcome is the main question the study is designed to answer.
Efficacy of infusion of ascorbic acid
The difference in sympathetic-vascular transduction (mmHg) between ascorbic acid and placebo infusion will be taken as a measure of the modulation of SVT by oxidative stress.
Measured: 30 minutes
Efficacy of infusion of ascorbic acid
The difference in sympathetic-vascular transduction (mmHg) between ascorbic acid and placebo infusion will be taken as a measure of the modulation of SVT by oxidative stress.
Measured: 60 minutes
Efficacy of infusion of ascorbic acid
The difference in sympathetic-vascular transduction (mmHg) between ascorbic acid and placebo infusion will be taken as a measure of the modulation of SVT by oxidative stress.
Measured: 90 minutes
Efficacy of infusion of ascorbic acid
The difference in sympathetic-vascular transduction (mmHg) between ascorbic acid and placebo infusion will be taken as a measure of the modulation of SVT by oxidative stress.
Measured: 120 minutes
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted20 Jan 2021
- Study start17 Jun 2021
- Primary completion1 Aug 2026 (estimated)
- Study completion1 Aug 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for HypertensionStudies of the same condition, open and under way.
- More trials run by University of Kansas Medical CenterThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 1/2
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Double blind
- Who is masked
- Participant, Investigator
- Enrolment
- 23 participants (estimated)
Sponsor and investigators
- Lead sponsor
- University of Kansas Medical Center
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Seth Holwerda PhD, University of Kansas Medical Center
- Investigators
- Seth Holwerda, PhD, Principal investigator, University of Kansas Medical Center
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04715022
- Sponsor's protocol ID
- STUDY00146744
- Status last verified
- Jun 2025
- First submitted
- 10 Jan 2021
- Last updated
- 8 Jun 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 8 Jun 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Sympathetic-vascular Dysfunction in Obesity and Insulin Resistance
- ClinicalTrials.gov ID
- NCT04715022
- Acronym / sponsor ID
- STUDY00146744
- Conditions
- Hypertension, Cardiovascular Diseases
- Phase
- Phase 1/2
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 23 participants (estimated)
- Lead sponsor
- University of Kansas Medical CenterUniversity, hospital or other
- Study start
- 17 Jun 2021 (actual)
- Primary completion
- 1 Aug 2026 (estimated)
- Study completion
- 1 Aug 2027 (estimated)
- First posted
- 20 Jan 2021 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The main purpose of research is to examine and understanding the development of hypertension in obese adults with insulin resistance. Findings from our studies will identify unique mechanisms that can be targeted to limit increases in vascular dysfunction and reduce the excessively high prevalence of hypertension and risk for cardiovascular disease (CVD).
This study is testing the health of the blood vessels and the activity of the nerves that control the blood vessels in adults with insulin resistance. The extent to which ascorbic acid (Vitamin C) improves the function of the blood vessels will be determined. The primary outcome is blood pressure, which is the result of blood vessel health and activity of the nerves, and the reduction in blood pressure that is observed with ascorbic acid.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Double blind (participant, investigator)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Placebo infusion | Placebo comparator | Drug: SalineSaline will be administered over 2 hours |
| Ascorbic acid infusion | Active comparator | Drug: Ascorbic acid solution (American Regent Laboratories Inc.)Ascorbic acid solution (American Regent Laboratories Inc.) will be obtained from the KU Investigational Pharmacy located in the University of Kansas (KU) Clinical Research Center where studies will take place. A priming bolus of 0.06 g ascorbic acid/kg fat free mass (FFM) dissolved in 100 mL of saline will be infused intravenously at 5 mL/min for 20 minutes, followed immediately by a "drip-infusion" of 0.02 g/kg FFM dissolved in 30 mL of saline administered over 2 hours at 0.5 mL/min. |
Who may qualify
- Ages
- 35 to 65 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (4 listed)
- Obese: BMI >30 m/kg2
- Middle-aged: 35-65 years
- Participants must be willing and able to discontinue taking any vitamin C or E supplements or omega-3 fatty acids beginning 2 weeks prior.
- Able and willing to provide written informed consent
Key exclusion criteria (6 listed)
- Diabetes mellitus: fasting glucose < 1267 mg/dL and/or HbA1c < 6.5%
- Currently taking a statin or antihypertension medication
- Hyperlipidemia: Fasting triglycerides < 250 mg/dL
- Hypertension: <130/80 mmHg
- History of heart disease (e.g., myocardial infarction, stent)
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Ascorbic acid solution (American Regent Laboratories Inc.)Ascorbic acid solution (American Regent Laboratories Inc.) will be obtained from the KU Investigational Pharmacy located in the KU Clinical Research Center where studies will take place. A priming bolus of 0.06 g ascorbic acid/kg fat free mass (FFM) dissolved in 100 mL of saline will be infused intravenously at 5 mL/min for 20 minutes, followed immediately by a "drip-infusion" of 0.02 g/kg FFM dissolved in 30 mL of saline administered over 2 hours at 0.5 mL/min. | Drug | Ascorbic acid infusion |
| SalinePlacebo (saline) will be administered | Drug | Placebo infusion |
Primary outcome
Efficacy of infusion of ascorbic acid
Time frame: 30 minutes
The difference in sympathetic-vascular transduction (mmHg) between ascorbic acid and placebo infusion will be taken as a measure of the modulation of SVT by oxidative stress.
Efficacy of infusion of ascorbic acid
Time frame: 60 minutes
The difference in sympathetic-vascular transduction (mmHg) between ascorbic acid and placebo infusion will be taken as a measure of the modulation of SVT by oxidative stress.
Efficacy of infusion of ascorbic acid
Time frame: 90 minutes
The difference in sympathetic-vascular transduction (mmHg) between ascorbic acid and placebo infusion will be taken as a measure of the modulation of SVT by oxidative stress.
Efficacy of infusion of ascorbic acid
Time frame: 120 minutes
The difference in sympathetic-vascular transduction (mmHg) between ascorbic acid and placebo infusion will be taken as a measure of the modulation of SVT by oxidative stress.
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 8 Jun 2025.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Seth Holwerda, PhD principal investigator
University of Kansas Medical Center
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 1/2 study testing Ascorbic acid solution (American Regent Laboratories Inc.) and Saline in people with Hypertension and Cardiovascular Diseases, run by University of Kansas Medical Center at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 4 inclusion and 6 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 8 Jun 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this combined phase mean?
Phase 1 studies test a treatment in a small group of people for the first time or in a new way, mainly to check safety and find the right dose.
Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Seth Holwerda, PhD (9729223230, sholwerda@kumc.edu), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Efficacy of infusion of ascorbic acid (time frame: 30 minutes). The study lists 4 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 8 Jun 2025.