Are You Having a Healthy Change of Heart? An HRV Sensor Can Tell You.
Scientists have known about and studied heart rate variability, or HRV, for a long time and, in recent years, monitors have come to market that can measure HRV accurately.
This episode is about a health metric you may not have heard of before: heart rate variability, or HRV. This refers to the small changes in the length of time between each of your heart beats.
Scientists have known about and studied HRV for a long time. In recent years, though, new monitors have come to market that can measure HRV accurately whenever you want.
Five months ago, I got interested in HRV as a more scientific approach to finding the lifestyle changes that work best for me as an individual. It's at the convergence of some important trends in health right now, such as health tech, precision health and the holistic approach in systems biology, which recognizes how interactions among different parts of the body are key to health.
But HRV is just one of many numbers worth paying attention to. For this episode of Making Sense of Science, I spoke with psychologist Dr. Leah Lagos; Dr. Jessilyn Dunn, assistant professor in biomedical engineering at Duke; and Jason Moore, the CEO of Spren and an app called Elite HRV. We talked about what HRV is, research on its benefits, how to measure it, whether it can be used to make improvements in health, and what researchers still need to learn about HRV.
*Talk to your doctor before trying anything discussed in this episode related to HRV and lifestyle changes to raise it.
Listen on Apple | Listen on Spotify | Listen on Stitcher | Listen on Amazon | Listen on Google
Show notes
Spren - https://www.spren.com/
Elite HRV - https://elitehrv.com/
Jason Moore's Twitter - https://twitter.com/jasonmooreme?lang=en
Dr. Jessilyn Dunn's Twitter - https://twitter.com/drjessilyn?lang=en
Dr. Dunn's study on HRV, flu and common cold - https://jamanetwork.com/journals/jamanetworkopen/f...
Dr. Leah Lagos - https://drleahlagos.com/
Dr. Lagos on Star Talk - https://www.youtube.com/watch?v=jC2Q10SonV8
Research on HRV and intermittent fasting - https://pubmed.ncbi.nlm.nih.gov/33859841/
Research on HRV and Mediterranean diet - https://medicalxpress.com/news/2010-06-twin-medite...:~:text=Using%20data%20from%20the%20Emory,eating%20a%20Western%2Dtype%20diet
Devices for HRV biofeedback - https://elitehrv.com/heart-variability-monitors-an...
Benefits of HRV biofeedback - https://pubmed.ncbi.nlm.nih.gov/32385728/
HRV and cognitive performance - https://www.frontiersin.org/articles/10.3389/fnins...
HRV and emotional regulation - https://pubmed.ncbi.nlm.nih.gov/36030986/
Fortune article on HRV - https://fortune.com/well/2022/12/26/heart-rate-var...
Did Anton the AI find a new treatment for a deadly cancer?
Researchers used a supercomputer to learn about the subtle movement of a cancer-causing molecule, and then they found the precise drug that can recognize that motion.
Bile duct cancer is a rare and aggressive form of cancer that is often difficult to diagnose. Patients with advanced forms of the disease have an average life expectancy of less than two years.
Many patients who get cancer in their bile ducts – the tubes that carry digestive fluid from the liver to the small intestine – have mutations in the protein FGFR2, which leads cells to grow uncontrollably. One treatment option is chemotherapy, but it’s toxic to both cancer cells and healthy cells, failing to distinguish between the two. Increasingly, cancer researchers are focusing on biomarker directed therapy, or making drugs that target a particular molecule that causes the disease – FGFR2, in the case of bile duct cancer.
A problem is that in targeting FGFR2, these drugs inadvertently inhibit the FGFR1 protein, which looks almost identical. This causes elevated phosphate levels, which is a sign of kidney damage, so doses are often limited to prevent complications.
In recent years, though, a company called Relay has taken a unique approach to picking out FGFR2, using a powerful supercomputer to simulate how proteins move and change shape. The team, leveraging this AI capability, discovered that FGFR2 and FGFR1 move differently, which enabled them to create a more precise drug.
Preliminary studies have shown robust activity of this drug, called RLY-4008, in FGFR2 altered tumors, especially in bile duct cancer. The drug did not inhibit FGFR1 or cause significant side effects. “RLY-4008 is a prime example of a precision oncology therapeutic with its highly selective and potent targeting of FGFR2 genetic alterations and resistance mutations,” says Lipika Goyal, assistant professor of medicine at Harvard Medical School. She is a principal investigator of Relay’s phase 1-2 clinical trial.
Boosts from AI and a billionaire
Traditional drug design has been very much a case of trial and error, as scientists investigate many molecules to see which ones bind to the intended target and bind less to other targets.
“It’s being done almost blindly, without really being guided by structure, so it fails very often,” says Olivier Elemento, associate director of the Institute for Computational Biomedicine at Cornell. “The issue is that they are not sampling enough molecules to cover some of the chemical space that would be specific to the target of interest and not specific to others.”
Relay’s unique hardware and software allow simulations that could never be achieved through traditional experiments, Elemento says.
Some scientists have tried to use X-rays of crystallized proteins to look at the structure of proteins and design better drugs. But they have failed to account for an important factor: proteins are moving and constantly folding into different shapes.
David Shaw, a hedge fund billionaire, wanted to help improve drug discovery and understood that a key obstacle was that computer models of molecular dynamics were limited; they simulated motion for less than 10 millionths of a second.
In 2001, Shaw set up his own research facility, D.E. Shaw Research, to create a supercomputer that would be specifically designed to simulate protein motion. Seven years later, he succeeded in firing up a supercomputer that can now conduct high speed simulations roughly 100 times faster than others. Called Anton, it has special computer chips to enable this speed, and its software is powered by AI to conduct many simulations.
After creating the supercomputer, Shaw teamed up with leading scientists who were interested in molecular motion, and they founded Relay Therapeutics.
Elemento believes that Relay’s approach is highly beneficial in designing a better drug for bile duct cancer. “Relay Therapeutics has a cutting-edge approach for molecular dynamics that I don’t believe any other companies have, at least not as advanced.” Relay’s unique hardware and software allow simulations that could never be achieved through traditional experiments, Elemento says.
How it works
Relay used both experimental and computational approaches to design RLY-4008. The team started out by taking X-rays of crystallized versions of both their intended target, FGFR2, and the almost identical FGFR1. This enabled them to get a 3D snapshot of each of their structures. They then fed the X-rays into the Anton supercomputer to simulate how the proteins were likely to move.
Anton’s simulations showed that the FGFR1 protein had a flap that moved more frequently than FGFR2. Based on this distinct motion, the team tried to design a compound that would recognize this flap shifting around and bind to FGFR2 while steering away from its more active lookalike.
For that, they went back Anton, using the supercomputer to simulate the behavior of thousands of potential molecules for over a year, looking at what made a particular molecule selective to the target versus another molecule that wasn’t. These insights led them to determine the best compounds to make and test in the lab and, ultimately, they found that RLY-4008 was the most effective.
Promising results so far
Relay began phase 1-2 trials in 2020 and will continue until 2024. Preliminary results showed that, in the 17 patients taking a 70 mg dose of RLY-4008, the drug worked to shrink tumors in 88 percent of patients. This was a significant increase compared to other FGFR inhibitors. For instance, Futibatinib, which recently got FDA approval, had a response rate of only 42 percent.
Across all dose levels, RLY-4008 shrank tumors by 63 percent in 38 patients. In more good news, the drug didn’t elevate their phosphate levels, which suggests that it could be taken without increasing patients’ risk for kidney disease.
“Objectively, this is pretty remarkable,” says Elemento. “In a small patient study, you have a molecule that is able to shrink tumors in such a high fraction of patients. It is unusual to see such good results in a phase 1-2 trial.”
A simulated future
The research team is continuing to use molecular dynamic simulations to develop other new drug, such as one that is being studied in patients with solid tumors and breast cancer.
As for their bile duct cancer drug, RLY-4008, Relay plans by 2024 to have tested it in around 440 patients. “The mature results of the phase 1-2 trial are highly anticipated,” says Goyal, the principal investigator of the trial.
Sameek Roychowdhury, an oncologist and associate professor of internal medicine at Ohio State University, highlights the need for caution. “This has early signs of benefit, but we will look forward to seeing longer term results for benefit and side effect profiles. We need to think a few more steps ahead - these treatments are like the ’Whack-a-Mole game’ where cancer finds a way to become resistant to each subsequent drug.”
“I think the issue is going to be how durable are the responses to the drug and what are the mechanisms of resistance,” says Raymond Wadlow, an oncologist at the Inova Medical Group who specializes in gastrointestinal and haematological cancer. “But the results look promising. It is a much more selective inhibitor of the FGFR protein and less toxic. It’s been an exciting development.”
The Friday Five: How to exercise for cancer prevention
How to exercise for cancer prevention. Plus, a device that brings relief to back pain, ingredients for reducing Alzheimer's risk, the world's oldest disease could make you young again, and more.
The Friday Five covers five stories in research that you may have missed this week. There are plenty of controversies and troubling ethical issues in science – and we get into many of them in our online magazine – but this news roundup focuses on scientific creativity and progress to give you a therapeutic dose of inspiration headed into the weekend.
Listen on Apple | Listen on Spotify | Listen on Stitcher | Listen on Amazon | Listen on Google
Here are the promising studies covered in this week's Friday Five:
- How to exercise for cancer prevention
- A device that brings relief to back pain
- Ingredients for reducing Alzheimer's risk
- Is the world's oldest disease the fountain of youth?
- Scared of crossing bridges? Your phone can help