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

University of Kansas

Status and phase: Enrolling; Phase 2; Phase 1

Conditions: Hypertension; Cardiovascular Diseases

Treatments: Drug: Saline; Drug: Ascorbic acid solution (American Regent Laboratories Inc.)

Study type: Interventional

Funder types: Other

Identifiers

NCT04715022

STUDY00146744

Details and patient eligibility

About

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.

Enrollment: 23 estimated patients

Sex: All

Ages: 35 to 65 years old

Volunteers: No Healthy Volunteers

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)

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Crossover Assignment

Masking: Double Blind

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23 participants in 2 patient groups, including a placebo group

Placebo infusion

Placebo Comparator group

Description:

Saline will be administered over 2 hours

Treatment:

Drug: Saline

Ascorbic acid infusion

Active Comparator group

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.

Treatment:

Drug: Ascorbic acid solution (American Regent Laboratories Inc.)