Sympathetic-vascular Dysfunction in Obesity and Insulin Resistance (Vitamin C Study)

Hypertension Clinical Trial

Official title:

Sympathetic-vascular Dysfunction in Obesity and Insulin Resistance

Clinical Trial Details — Status: Recruiting

Administrative data

• NCT number: NCT04715022
• Other study ID #: STUDY00146744
• Status: Recruiting
• Phase: Phase 1/Phase 2
• Start date: June 17, 2021
• Est. completion date: April 1, 2025

Study information

• Verified date: October 2023
• Source: University of Kansas Medical Center
• Contact: Seth Holwerda, PhD
• Phone: 9729223230
• Email: sholwerda[@]kumc.edu
• Is FDA regulated: No
• Study type: Interventional

Clinical 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 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.

Recruitment information / eligibility

• Status: Recruiting
• Enrollment: 23
• Est. completion date: April 1, 2025
• Est. primary completion date: April 1, 2025
• Accepts healthy volunteers: No
• Gender: All
• Age group: 35 Years to 65 Years

Eligibility

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)

Related Conditions & MeSH terms

• Cardiovascular Diseases
• Hypertension
• Insulin Resistance

Intervention

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 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

Locations

Country	Name	City	State
United States	University of Kansas Medical Center	Kansas City	Kansas

Sponsors (1)

Lead Sponsor	Collaborator
University of Kansas Medical Center

Country where clinical trial is conducted

United States, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	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.	30 minutes
Primary	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.	60 minutes
Primary	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.	90 minutes
Primary	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.	120 minutes