Reversing Glucose and Lipid-mediated Vascular Dysfunction (REGAL)

University of Kansas

Status and phase: Enrolling; Early Phase 1

Conditions: Hypertension; Blood Pressure

Treatments: Drug: Saline; Drug: Dextrose 20 % in 500 ML Injection; Drug: Intralipid; Drug: Ascorbic acid

Study type: Interventional

Funder types: Other

Identifiers

NCT04832009

00147066

Details and patient eligibility

About

The purpose of our study is to understand the extent to which the blood vessels are affected by glucose and fat (lipids) in lean healthy adults and if these changes in the blood vessels contribute to the development of high blood pressure.

Full description

Hypertension, obesity, and insulin resistance are associated with elevated muscle sympathetic nerve activity (MSNA), which is important for blood pressure regulation. The measurement of MSNA is safely performed in humans using the microneurographic technique that involves recording sympathetic nerve activity projecting to skeletal muscle using a small microelectrode at the peroneal nerve near the knee.

The health of your blood vessels will be tested in this study, in addition to the activity of the nerves that control the blood vessels. The function of the nerves and blood vessels can be diminished by high blood glucose and lipids, and we will test the ability of a well-known antioxidant, ascorbic acid (vitamin C), to restore the function of the nerves and blood vessels.

Enrollment: 46 estimated patients

Sex: All

Ages: 18 to 79 years old

Volunteers: Accepts Healthy Volunteers

Inclusion criteria

• Lean: BMI < 25 kg/m
• Normal insulin sensitivity: (calculation based on fasting glucose and insulin concentrations in blood)
• Middle-aged: 18-79 years
• Blood pressure: < 140 (systolic) and < 90 mmHg (diastolic
• Weight stable (+/- 5 lbs) for the previous 3 months
• 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 Type I or Type II: fasting glucose < 126 mg/dL and/or HbA1c < 6.5%
• Current smoker or History of smoking in the past 3 months.
• Hyperlipidemia: Fasting triglycerides < 250 mg/dL
• Hypertension: >130/80 mmHg
• History of heart disease (e.g., myocardial infarction, stent, heart attack, stroke, heart failure, valvular heart disease, cardiomyopathy)
• History of vascular disease (e.g., bypass, stroke)

Trial design

Primary purpose: Other

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Triple Blind

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46 participants in 2 patient groups

Glucose Infusion

Experimental group

Description:

Hyperglycemia (glucose infusion) will receive an I.V. Glucose infusion with a co-infusion of ascorbic acid or placebo at your visit 2 and the alternative treatment of ascorbic acid or placebo will be given on the subsequent study visit 3.

Treatment:

Drug: Ascorbic acid

Drug: Dextrose 20 % in 500 ML Injection

Drug: Saline

Lipid Infusion

Experimental group

Description:

Hyperlipidemia (lipid infusion) will receive an I.V. Lipid infusion with a co-infusion of ascorbic acid or placebo at your visit 2 and the alternative treatment of ascorbic acid or placebo will be given on the subsequent study visit 3.

Treatment:

Drug: Ascorbic acid

Drug: Intralipid

Drug: Saline