Effects of Exercise Training Intensity and Inorganic Nitrate Supplementation on Vascular Health and Fitness in Post-Menopausal Females
Overview
- Phase
- Not Applicable
- Intervention
- Not specified
- Conditions
- Menopause
- Sponsor
- University of Virginia
- Enrollment
- 40
- Locations
- 1
- Primary Endpoint
- Cardiorespiratory Fitness
- Status
- Recruiting
- Last Updated
- 9 months ago
Overview
Brief Summary
Menopause greatly increases cardiovascular disease risk (CVD). Current exercise guidelines are inadequate to ameliorate this risk and higher intensity exercise may be necessary for cardiovascular benefits in postmenopausal females. Oral nitrate supplementation enhances exercise performance and CVD risk profile in several clinical conditions. The investigators recently reported that 3-days of nitrate supplementation in postmenopausal females enhances acute post-exercise vascular function, in an intensity dependent manner. The effects of nitrate supplementation and exercise training over a longer training program remains unexplored. This investigation will examine the impact of exercise training intensity with and without inorganic nitrate supplementation, on CVD and fitness outcomes. Postmenopausal females will be tested for maximal oxygen uptake and lactate threshold before randomization to one of four groups: that inorganic nitrate-rich beetroot juice, or beetroot juice with nitrate extracted; and assigned to one-month of calorie matched high-intensity or moderate-intensity exercise training. Vascular function and fitness will be evaluated before and after training.
Investigators
Jason Allen
Professor
University of Virginia
Eligibility Criteria
Inclusion Criteria
- •Post-menopausal female (greater than age 45 but less than age 75)
- •Sedentary (does not exercise regularly or less than 2 bouts of exercise per week)
- •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.)
- •Oral antibiotic use within previous four weeks
- •Oral disease or poor oral health as determined by the Oral Health Questionnaire
- •Using an antibacterial mouthwash or a mouthwash containing chlorhexidine and unwilling to discontinue use
Outcomes
Primary Outcomes
Cardiorespiratory Fitness
Time Frame: Baseline and after 1-month of exercise training
Peak aerobic capacity (VO2peak) will be assessed using a symptom-limited graded exercise test on a treadmill. An IV will be placed and lactate measured during rest and after the completion of every 3-minute stage to determine lactate threshold at VO2peak.
Vascular Endothelial Function (Flow-Mediated Dilation [FMD])
Time Frame: Baseline and after 1-month of exercise training
Participants will be placed in a supine position with their left forearm slightly extended and supinated with legs straight. The arteries will be imaged using a high-resolution 7.5MHz linear array transducer at rest, during 5 minutes of forearm occlusion via cuff inflation, and continuously for 3 minutes post-occlusion; an EKG trigger will be used to capture images during end-diastole of the cardiac cycle.
Secondary Outcomes
- Oral Nitrate Reducing Capacity(Baseline and after 1-month of exercise training)
- Skeletal muscle perfusion(Baseline and after 1-month of exercise training)
- Peripheral and Central Blood Pressures(Baseline and after 1-month of exercise training)
- 24-hour ambulatory blood pressure(Baseline and after 1-month of exercise training)
- Skeletal muscle microvascular perfusion (near-infra-red- spectroscopy)(Baseline and after 1-month of exercise training)
- Lipids(Baseline)
- Hemoglobin(Baseline and after 1-month of exercise training)
- Plasma Nitrate(Baseline and after 1-month of exercise training)
- Plasma Nitrite(Baseline and after 1-month of exercise training)