By Lisa Farr, M.Ed. Director, Exercise Physiology Core Lab
Interview with Austin Hogwood, MS, doctoral candidate. The principal investigator of the study is Arthur Weltman, Ph.D, Professor. Austin is working closely with both Art and another Kinesiology Professor Jason Allen. The study is funded by a UVA IDEA grant.
Menopause is an inevitable process for females characterized by loss of endogenous estradiol. While pre-menopausal women have a lower risk of cardiovascular disease, menopause results in a dramatic increase in prevalence.
Nitric oxide is essential for vascular function/health. Although aging in general is associated with decreases in bioavailable nitric oxide and impaired vascular health and function, the postmenopausal state appears to have particularly deleterious effects.
The short half-life of NO in biological systems makes it difficult to measure directly. Non-invasive physiological measures of peripheral vascular health such as flow-mediated dilation (FMD) are known to correlate to nitric oxide bioavailability and coronary artery function and can be used for early prediction of cardiovascular disease risk.
Estradiol (the most abundant estrogen) treatment improves NO bioavailability and vascular health in PM females, however estradiol treatment does not restore vascular health to the level observed in premenopausal females. In addition, there are both potential risks and benefits of post-menopausal estrogen replacement; thus other therapeutic targets are necessary to improve vascular health and reduce cardiovascular risk in these women.
Both exercise training and oral inorganic nitrate dietary intake and/or supplementation are approaches that can increase nitric oxide synthesis and/or reduce nitric oxide inactivation, resulting in improved vascular function. While exercise training appears to be beneficial for vascular health and function in post-menopausal females, evidence suggests it is less so than in age-matched males. This could be related to the intensity of the exercise used in studies examining these issues. Recent evidence suggests that post-menopausal females may need a higher exercise intensity to see benefits to cardiovascular health.
Dietary inorganic nitrate (NO3–) is found in several foods, such as green leafy vegetables, celery, and beetroot, and consumption of these foods is associated with improved cardiovascular risk outcomes in older adults. Inorganic nitrate can also be consumed via supplementation, such as beetroot juice, and preliminary studies have indicated it has powerful effects on vascular health, and in improving high intensity exercise performance. Despite the growing evidence related to the efficacy of NO3– supplementation to improve exercise performance, no research has examined the effects of NO3– and exercise intensity on associated clinical outcomes in post-menopausal females
Austin Hogwood, Art Weltman, Jason Allen, and their colleagues in Kinesiology, are studying this issue.
Questions and Answers with Austin Hogwood
Why did you want to study beetroot juice and vascular health in post-menopausal women?
Austin: Women are under-studied, so that’s a big reason. But also—post-menopausal women have a lesser response to exercise than age-matched men. Why? Is it because most studies have used only moderate exercise? Or something else, something specific to the post-menopausal state.
We know exercise can offset some of the vascular effects that we tend to see post-menopause, but not to pre-menopause levels. Why is this? Is exercise intensity a key factor here? As we move towards precision in medicine, we also need to move towards precision in exercise prescription.
So the real-life application here is–?
While any exercise is better than none, we need to be able to provide more specific recommendations than that if we want to best serve specific populations, including post-menopausal women.
Can you describe the study procedure?
After screening to ensure eligibility, subjects will have a DEXA scan to determine body composition. Subjects will complete a dietary recall questionnaire, have labs drawn, and will have ultrasound imaging on the arm. (editor note: This test is called FMD, and it is s a good way to assess vascular health and get a sense of nitric oxide bioavailability)
Subjects will be assigned supplementation with beetroot juice or a placebo (that is identical other than having the NO3– removed)
A maximal exercise test on the bike is performed. This test sets the exercise prescription for 2 of the next visits.
Subjects have 3 visits while taking either the placebo or the beetroot juice: a rest visit, + 2 exercise visits. The exercise visits are calorie-matched exercise sessions that differ in intensity—one visit is a longer, easier session on the stationary bike and the other is a shorter, harder session on the bike. These visits also include other measures: a repeat of the arm FMD; tests that requires blood pressure cuffs be placed on both the arms and the legs, and blood draws.
Subjects can also opt in or out of sleep tracking throughout the study. This involves wearing a watch throughout the study to determine if exercise or inorganic nitrate supplementation can improve sleep quality
Compensation for those who complete the study is $200. Subjects will also receive their body composition results if desired.
Art and Austin are recruiting post-menopausal females ages 45 – 75 who do not smoke or exercise regularly, and who do not take hormone replacement therapy. There are a few other medications prohibited, such as nitrates and anti-arrhythmics. For more specific information about the study contact Austin at firstname.lastname@example.org or see the UVA clinical trials site and search for HSR # 210326.
While catching up with Austin about his important new study, we also took a moment to get a little personal too
Austin, I know you are from Colonial Heights VA, and that you attended VCU for both your undergrad and master’s degrees. But I wasn’t sure what led you to the field of exercise science? Also wanted to ask—what advice would you give your younger self as related to exercise?
I started out as a mechanical engineering student (at VCU) But exercise had always been a big part of my life—I was a soccer player growing up, and my Dad was a professional boxer. I started to ask myself what would make me happy career wise and exercise science was it. I shadowed in a physical therapy clinic and also in a cardiac rehab setting, but what I really liked was the lab setting. I wanted to do research related to exercise. As for your second question it would have to be “Listen to your body!” I spent 5 years stubbornly pushing through injury. If I had listened from the start the injury would have been less severe and not as long lasting.