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

Primary Purpose

Hypertension, Cardiovascular Diseases

Status
Recruiting
Phase
Phase 1
Locations
United States
Study Type
Interventional
Intervention
Ascorbic acid solution (American Regent Laboratories Inc.)
Saline
Sponsored by
University of Kansas Medical Center
About
Eligibility
Locations
Arms
Outcomes
Full info

About this trial

This is an interventional treatment trial for Hypertension

Eligibility Criteria

35 Years - 65 Years (Adult, Older Adult)All SexesDoes not accept healthy volunteers

Inclusion Criteria:

  1. Obese: BMI >30 m/kg2
  2. Elevated insulin resistance: Homeostatic Model Assessment of Insulin Resistance (HOMA-IR) > 2.5 (calculation based on fasting glucose and insulin concentrations in blood)
  3. Middle-aged: 35-65 years
  4. Participants must be willing and able to discontinue taking any vitamin C or E supplements or omega-3 fatty acids beginning 2 weeks prior.
  5. 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)

Sites / Locations

  • University of Kansas Medical CenterRecruiting

Arms of the Study

Arm 1

Arm 2

Arm Type

Placebo Comparator

Active Comparator

Arm Label

Placebo infusion

Ascorbic acid infusion

Arm Description

Saline will be administered over 2 hours

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.

Outcomes

Primary Outcome Measures

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.
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.
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.
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.

Secondary Outcome Measures

Full Information

First Posted
January 10, 2021
Last Updated
October 20, 2023
Sponsor
University of Kansas Medical Center
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1. Study Identification

Unique Protocol Identification Number
NCT04715022
Brief Title
Sympathetic-vascular Dysfunction in Obesity and Insulin Resistance (Vitamin C Study)
Official Title
Sympathetic-vascular Dysfunction in Obesity and Insulin Resistance
Study Type
Interventional

2. Study Status

Record Verification Date
October 2023
Overall Recruitment Status
Recruiting
Study Start Date
June 17, 2021 (Actual)
Primary Completion Date
April 1, 2025 (Anticipated)
Study Completion Date
April 1, 2025 (Anticipated)

3. Sponsor/Collaborators

Responsible Party, by Official Title
Principal Investigator
Name of the Sponsor
University of Kansas Medical Center

4. Oversight

Studies a U.S. FDA-regulated Drug Product
Yes
Studies a U.S. FDA-regulated Device Product
No
Product Manufactured in and Exported from the U.S.
Yes
Data Monitoring Committee
No

5. Study Description

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.

6. Conditions and Keywords

Primary Disease or Condition Being Studied in the Trial, or the Focus of the Study
Hypertension, Cardiovascular Diseases

7. Study Design

Primary Purpose
Treatment
Study Phase
Phase 1, Phase 2
Interventional Study Model
Crossover Assignment
Masking
ParticipantInvestigator
Allocation
Randomized
Enrollment
23 (Anticipated)

8. Arms, Groups, and Interventions

Arm Title
Placebo infusion
Arm Type
Placebo Comparator
Arm Description
Saline will be administered over 2 hours
Arm Title
Ascorbic acid infusion
Arm Type
Active Comparator
Arm Description
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.
Intervention Type
Drug
Intervention Name(s)
Ascorbic acid solution (American Regent Laboratories Inc.)
Intervention Description
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.
Intervention Type
Drug
Intervention Name(s)
Saline
Intervention Description
Placebo (saline) will be administered
Primary Outcome Measure Information:
Title
Efficacy of infusion of ascorbic acid
Description
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.
Time Frame
30 minutes
Title
Efficacy of infusion of ascorbic acid
Description
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.
Time Frame
60 minutes
Title
Efficacy of infusion of ascorbic acid
Description
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.
Time Frame
90 minutes
Title
Efficacy of infusion of ascorbic acid
Description
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.
Time Frame
120 minutes

10. Eligibility

Sex
All
Minimum Age & Unit of Time
35 Years
Maximum Age & Unit of Time
65 Years
Accepts Healthy Volunteers
No
Eligibility Criteria
Inclusion Criteria: 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 Exclusion Criteria: 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)
Central Contact Person:
First Name & Middle Initial & Last Name or Official Title & Degree
Seth Holwerda, PhD
Phone
9729223230
Email
sholwerda@kumc.edu
First Name & Middle Initial & Last Name or Official Title & Degree
Manuel Clark, MPA
Phone
913-945-5763
Email
mclark16@kumc.edi
Overall Study Officials:
First Name & Middle Initial & Last Name & Degree
Seth Holwerda, PhD
Organizational Affiliation
University of Kansas Medical Center
Official's Role
Principal Investigator
Facility Information:
Facility Name
University of Kansas Medical Center
City
Kansas City
State/Province
Kansas
ZIP/Postal Code
66160
Country
United States
Individual Site Status
Recruiting
Facility Contact:
First Name & Middle Initial & Last Name & Degree
Davina Clonch
Phone
913-226-6009
Email
dclonch@kumc.edu
First Name & Middle Initial & Last Name & Degree
Megan Gangwish
Phone
913-444-0949
Email
mgangwish@kumc.edu

12. IPD Sharing Statement

Plan to Share IPD
No

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

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