Arterial Stiffness, Vascular Dilation
Conditions
Keywords
Flow-mediated dilation, Pulse wave velocity, Exercise intensity, Vascular function
Brief summary
Post-menopausal females experience elevated cardiovascular disease risk (CVD), compared to premenopausal females and age-matched males. Current exercise guidelines appear inadequate to ameliorate this increased risk and higher intensity exercise may be necessary. Oral inorganic nitrate supplementation enhances both exercise performance and CVD risk profile in several clinical conditions. However, the effects of this intervention in post-menopausal females is unexplored.
Detailed description
The purpose of this study is to determine whether acute inorganic nitrate supplementation and exercising at different exercise intensities (high vs moderate) improve vascular health in post-menopausal females.
Interventions
Beet It Sport (James White Drinks, Ltd.) each containing 400mg of inorganic nitrate (\ 6.5 mmol) will be consumed twice daily (totalling \ 13 mmol of inorganic nitrate per day) for at least 2 days prior to testing visits, as well as 2 hours prior to testing visits.
Beet It Sport (James White Drinks, Ltd.) each containing 0mg of inorganic nitrate (\ 0 mmol) will be consumed twice daily (totalling \ 0 mmol of inorganic nitrate per day) for at least 2 days prior to testing visits, as well as 2 hours prior to testing visits. It is provided by the same company that produces the concentrated beet root juice shots (James White Drinks) but the placebo version is nitrate-depleted.
Sponsors
University of Virginia
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
BASIC_SCIENCE
Masking
DOUBLE (Subject, Investigator)
Masking description
This is a double-blind study, where neither the investigators nor the subjects will know whether the participants are receiving the active supplement or placebo supplement until study conclusion.
Intervention model description
Subject are stratified randomized to consume either beetroot juice with, or without, inorganic nitrate and will consume this same supplement throughout all testing
Eligibility
Sex/Gender
FEMALE
Age
45 Years to 75 Years
Healthy volunteers
Yes
Inclusion criteria
* Post-menopausal female, defined as having not had a menstrual cycle for at least 1 year * Greater than age 45 but less than age 75 * Sedentary (does not exercise regularly) * No major changes in medication in the last 3 months
Exclusion criteria
* Smokers within last 5 years * Weight unstable (loss/gain of more than 3kg in the past 3 months) * Any medical condition that prevents the subject from exercising safely * Hormone replacement therapy (current or within last 3 months) * Currently or recently on vasoactive medications (i.e., calcium channel blockers, statins, ACE or renin inhibitors, ARBs, nitrates, alpha- or beta-blockers, diuretics, proton pump inhibitors, etc.) * Hysterectomy or oophorectomy
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Post-Exercise/Control Flow-Mediated Dilation (180 min) | 180 minutes post-baseline. | Participants will be placed in a supine position with their left forearm slightly extended and supinated with legs straight. The brachial artery will be imaged using a high-resolution doppler ultrasound utilizing a 7.5MHz linear array transducer at rest, during 5 minutes of forearm occlusion via cuff inflation, and continuously for 2 minutes post-occlusion; an EKG trigger will be used to capture images during end-diastole of the cardiac cycle. Images will be analyzed offline using specialized software (Medical Imaging Applications, Inc.) to calculate the change in brachial artery diameter. |
| Baseline Flow-Mediated Dilation | Baseline (minute 0). | Participants will be placed in a supine position with their left forearm slightly extended and supinated with legs straight. The brachial artery will be imaged using a high-resolution doppler ultrasound utilizing a 7.5MHz linear array transducer at rest, during 5 minutes of forearm occlusion via cuff inflation, and continuously for 2 minutes post-occlusion; an EKG trigger will be used to capture images during end-diastole of the cardiac cycle. Images will be analyzed offline using specialized software (Medical Imaging Applications, Inc.) to calculate the change in brachial artery diameter. |
| Post-Exercise/Control Flow-Mediated Dilation (60 minutes) | 60 minutes post-baseline. | Participants will be placed in a supine position with their left forearm slightly extended and supinated with legs straight. The brachial artery will be imaged using a high-resolution doppler ultrasound utilizing a 7.5MHz linear array transducer at rest, during 5 minutes of forearm occlusion via cuff inflation, and continuously for 2 minutes post-occlusion; an EKG trigger will be used to capture images during end-diastole of the cardiac cycle. Images will be analyzed offline using specialized software (Medical Imaging Applications, Inc.) to calculate the change in brachial artery diameter. |
| Post-Exercise/Control Flow-Mediated Dilation (90 minutes) | 90 minutes post-baseline. | Participants will be placed in a supine position with their left forearm slightly extended and supinated with legs straight. The brachial artery will be imaged using a high-resolution doppler ultrasound utilizing a 7.5MHz linear array transducer at rest, during 5 minutes of forearm occlusion via cuff inflation, and continuously for 2 minutes post-occlusion; an EKG trigger will be used to capture images during end-diastole of the cardiac cycle. Images will be analyzed offline using specialized software (Medical Imaging Applications, Inc.) to calculate the change in brachial artery diameter. |
| Post-Exercise/Control Flow-Mediated Dilation (120 minutes) | 120 minutes post-baseline. | Participants will be placed in a supine position with their left forearm slightly extended and supinated with legs straight. The brachial artery will be imaged using a high-resolution doppler ultrasound utilizing a 7.5MHz linear array transducer at rest, during 5 minutes of forearm occlusion via cuff inflation, and continuously for 2 minutes post-occlusion; an EKG trigger will be used to capture images during end-diastole of the cardiac cycle. Images will be analyzed offline using specialized software (Medical Imaging Applications, Inc.) to calculate the change in brachial artery diameter. |
| Post-Exercise/Control Flow-Mediated Dilation (150 min) | 150 minutes post-baseline. | Participants will be placed in a supine position with their left forearm slightly extended and supinated with legs straight. The brachial artery will be imaged using a high-resolution doppler ultrasound utilizing a 7.5MHz linear array transducer at rest, during 5 minutes of forearm occlusion via cuff inflation, and continuously for 2 minutes post-occlusion; an EKG trigger will be used to capture images during end-diastole of the cardiac cycle. Images will be analyzed offline using specialized software (Medical Imaging Applications, Inc.) to calculate the change in brachial artery diameter. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Baseline Pulse Wave Velocity | Baseline (minute 0). | Supine measures of carotid to femoral pulse wave velocity will be measured using a SphygmoCor Xcel device. |
| Post-Exercise/Control Pulse Wave Velocity (60 min) | 60 minutes post-baseline. | Supine measures of carotid to femoral pulse wave velocity will be measured using a SphygmoCor Xcel device. |
| Post-Exercise/Control Pulse Wave Velocity (90 min) | 90 minutes post-baseline. | Supine measures of carotid to femoral pulse wave velocity will be measured using a SphygmoCor Xcel device. |
| Post-Exercise/Control Pulse Wave Velocity (120 min) | 120 minutes post-baseline. | Supine measures of carotid to femoral pulse wave velocity will be measured using a SphygmoCor Xcel device. |
| Post-Exercise/Control Pulse Wave Velocity (150 min) | 150 minutes post-baseline. | Supine measures of carotid to femoral pulse wave velocity will be measured using a SphygmoCor Xcel device. |
| Post-Exercise/Control Pulse Wave Velocity (180 min) | 180 minutes post-baseline. | Supine measures of carotid to femoral pulse wave velocity will be measured using a SphygmoCor Xcel device. |
Countries
United States
Outcome results
None listed