Recruiting
Phase 1
Phase 2

Vitamin C

Sponsor:

University of Kansas Medical Center

Code:

NCT04715022

Conditions

Hypertension

Cardiovascular Diseases

Eligibility Criteria

Sex: All

Age: 35 - 65

Healthy Volunteers: Not accepted

Interventions

Ascorbic acid solution (American Regent Laboratories Inc.)

Saline

Study Details

Brief 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 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

Study ID

NCT04715022

Start date

Jun 17, 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: 35 - 65

Healthy Volunteers: Not accepted

Inclusion Criteria:

1. Obese: BMI >30 m/kg2
2. Middle-aged: 35-65 years
3. Participants must be willing and able to discontinue taking any vitamin C or E supplements or omega-3 fatty acids beginning 2 weeks prior.
4. Able and willing to provide written informed consent

Exclusion Criteria:

1. Diabetes mellitus: fasting glucose < 1267 mg/dL and/or HbA1c < 6.5%
2. Currently taking a statin or antihypertension medication
3. Hyperlipidemia: Fasting triglycerides < 250 mg/dL
4. Hypertension: <130/80 mmHg
5. History of heart disease (e.g., myocardial infarction, stent)
6. History of vascular disease (e.g., bypass, stroke)

Study Design

Enrollment

23 participants

Anticipated

Allocation

Randomized

Intervention Model

Crossover

Primary purpose

Treatment

Interventions and Outcome Measures

Arms

placebo comparator: Placebo infusion

Saline will be administered over 2 hours

active comparator: Ascorbic acid infusion

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.

Interventions

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.

Saline

Placebo (saline) will be administered

Primary outcome measure

  • Efficacy of infusion of ascorbic acid [ Time Frame: 30 minutes ]
  • Efficacy of infusion of ascorbic acid [ Time Frame: 60 minutes ]
  • Efficacy of infusion of ascorbic acid [ Time Frame: 90 minutes ]
  • Efficacy of infusion of ascorbic acid [ Time Frame: 120 minutes ]

Central Contacts and Locations

Central contacts

Seth Holwerda, PhD

9729223230sholwerda@kumc.edu

Manuel Clark, MPA

913-945-5763mclark16@kumc.edi

Locations

University of Kansas Medical Center

Recruiting

Kansas City, Kansas, United States, 66160

Contacts

Davina Clonch

913-226-6009dclonch@kumc.edu

Megan Gangwish

913-444-0949mgangwish@kumc.edu

More Information

Sponsor

University of Kansas Medical Center

Last update posted

Jun 8, 2025

Last verified

Jun, 2025

Trial information was received from ClinicalTrials.gov and was last updated on 2026-10-03. This information was provided to ClinicalTrials.gov by University of Kansas Medical Center on 2025-06-08. Recruitment status is synced daily from ClinicalTrials.gov and may not reflect the sponsor's current status. Confirm during your call.