Marlene Grenon, Space Medicine Trailblazer, Profiled by Society for Vascular Surgery
The multifaceted rarefied career of Marlene Grenon, M.D., C.M., aspiring astronaut cum UCSF vascular surgeon, was recently profiled in the October 2106 issue of "Vascular Specialist", a publication of the Society for Vascular Surgery (SVS) with a worldwide audience of vascular surgeons, interventional cardiologists, vascular and interventional radiologists, and other specialists.
Dr. Grenon, an Associate Professor in the Division of Vascular and Endovascular Surgery, has been on leading edge of research on how the human body, in particular the cardiovascular system, fares under the rigors of space travel.
Dr. Bruce Perler, chair of the SVS Foundation, called Dr. Grenon "one of our pioneers of today, standing squarely on the shoulders of the giants of yesterday", a testament to the groundbreaking nature of her research funded by several SVS grants.
The story, "Focus On Research: Healthier Living on Earth, in Space" explores several areas of Dr. Grenon's research, including the intersection of space travel and human health.
Space – that final frontier – is also a vast universe of data about vascular health and disease for SVS member Dr. Marlene Grenon.
Dr. Grenon, a vascular surgeon at the University of California San Francisco, is a 2011 SVS Foundation Clinical Research Seed Grant winner and the 2014 recipient of an NIH K23 Career Development Grant as well as an SVS Foundation Career Development Award.
She has been researching the effects of space flight and microgravity on astronauts since early in her career. And she continues to find ways to connect astronaut health to that of Earthlings below.
U.S. Apollo lunar astronauts seem to be five times more likely to die of cardiovascular disease than other astronauts, after accounting for other factors, according to a recently published paper in Scientific Reports by Dr. Michael Delp at Florida State University. His paper followed work by Dr. Grenon and colleagues on the effects of microgravity on endothelial cells published three years ago in the same journal.
An increased risk of cardiovascular disease in lunar astronauts could be the result of radiation beyond Earth’s atmosphere, low gravity (also known as microgravity), stress or other as yet unknown reasons, she said.
A review of data found 43 percent of Apollo astronauts were found to have cardiovascular disease, compared with the overall U.S. population rate of 27 percent.
“We know there are major changes to the cardiovascular system in microgravity,” Dr. Grenon said. “Now that we know that some astronauts are at increased risk of cardiovascular disease. It’s really important to make sure we can make space travel as safe as possible.”
Astronauts also experience episodes of orthostatic intolerance (low blood pressure) on re-entry to Earth, have a decrease in exercise tolerance and may also be at increased risk of cardiac arrhythmias.
Dr. Grenon has a personal interest in the health of astronauts, because she aspired to be one herself and remains hopeful of eventual space travel. A native of Quebec, she got her degree in space studies at the International Space University based in France. She went to medical school at McGill University and did a residency in cardiac surgery, followed by two years at Harvard MIT where, with NASA funding, she researched the cardiovascular effects of space flight.
From among some 5,000 Canadian applicants Dr. Grenon had been in the final 30 when she chose to re-set her career flight path – opting to pursue a specialty in academic vascular surgery instead. “This was the best way to incorporate all my passions,” she said.
The article further describes Dr. Grenon's research on the effects of Post-Traumatic Stress Disorder (PTSD) on veterans, notably worse endothelial function.
Dr. Grenon also has done extensive work with veterans at the San Francisco Veterans Affairs Medical Center. War veterans have a tremendous exposure to stress, which is very likely involved in the development of cardiovascular disease, she said.
That inquiry led to a paper published a few months ago in the Journal of the American Heart Association on the association between Post-Traumatic Stress Disorder (PTSD) and worse endothelial function in the studied outpatient population, even after adjusting for traditional risk factors for cardiovascular disease.
Dr. Grenon’s research findings and clinical experience with veterans has led her to start a Vascular Rehabilitation Program at the VA medical center, in which medical students serve as health coaches for veterans.
Veterans, PTSD, omega 3s, vascular health, space flight. How does it all come together?
“I am very interested in healthier living, nutrition and stress management, a big challenge in our society,” she said, “and my guiding focus is on where space medicine meets vascular surgery. I want to optimize health on Earth and in space.”