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Purpose

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

Eligibility

Eligible Ages
Between 35 Years and 65 Years
Eligible Genders
All
Accepts Healthy Volunteers
No

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

Phase
Phase 1/Phase 2
Study Type
Interventional
Allocation
Randomized
Intervention Model
Crossover Assignment
Primary Purpose
Treatment
Masking
Double (Participant, Investigator)

Arm Groups

ArmDescriptionAssigned Intervention
Placebo Comparator
Placebo infusion 		Saline will be administered over 2 hours
  • Drug: Saline
    Placebo (saline) will be administered
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.
  • 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.

Recruiting Locations

University of Kansas Medical Center
Kansas City, Kansas 66160
Contact:
Davina Clonch
913-226-6009
dclonch@kumc.edu

More Details

Status
Recruiting
Sponsor
University of Kansas Medical Center

Study Contact

Seth Holwerda, PhD
9729223230
sholwerda@kumc.edu

Notice

Study information shown on this site is derived from ClinicalTrials.gov (a public registry operated by the National Institutes of Health). The listing of studies provided is not certain to be all studies for which you might be eligible. Furthermore, study eligibility requirements can be difficult to understand and may change over time, so it is wise to speak with your medical care provider and individual research study teams when making decisions related to participation.