June 13 | 2022
Smartwatches can track COVID-19 symptoms, study finds
Susan Kreimer is a New York-based freelance journalist who has followed the landscape of health care since the late 1990s, initially as a staff reporter for major daily newspapers. She writes about breakthrough studies, personal health, and the business of clinical practice. Raised in the Chicago area, she holds a B.A. in Journalism/Mass Communication and French, with minors in German and Russian, from the University of Iowa and an M.S. from the Columbia University Graduate School of Journalism.
University of Michigan researchers found that new signals embedded in heart rate indicated when individuals were infected with COVID-19 and how ill they became.
Photo by DESIGNECOLOGIST on Unsplash
If a COVID-19 infection develops, a wearable device may eventually be able to clue you in. A study at the University of Michigan found that a smartwatch can monitor how symptoms progress.
The study evaluated the effects of COVID-19 with various factors derived from heart-rate data. This method also could be employed to detect other diseases, such as influenza and the common cold, at home or when medical resources are limited, such as during a pandemic or in developing countries.
Tracking students and medical interns across the country, the University of Michigan researchers found that new signals embedded in heart rate indicated when individuals were infected with COVID-19 and how ill they became.
For instance, they discovered that individuals with COVID-19 experienced an increase in heart rate per step after the onset of their symptoms. Meanwhile, people who reported a cough as one of their COVID-19 symptoms had a much more elevated heart rate per step than those without a cough.
“We previously developed a variety of algorithms to analyze data from wearable devices. So, when the COVID-19 pandemic hit, it was only natural to apply some of these algorithms to see if we can get a better understanding of disease progression,” says Caleb Mayer, a doctoral student in mathematics at the University of Michigan and a co-first author of the study.
People may not internally sense COVID-19’s direct impact on the heart, but “heart rate is a vital sign that gives a picture of overall health," says Daniel Forger, a University of Michigan professor.
Millions of people are tracking their heart rate through wearable devices. This information is already generating a tremendous amount of data for researchers to analyze, says co-author Daniel Forger, professor of mathematics and research professor of computational medicine and bioinformatics at the University of Michigan.
“Heart rate is affected by many different physiological signals,” Forger explains. “For instance, if your lungs aren’t functioning properly, your heart may need to beat faster to meet metabolic demands. Your heart rate has a natural daily rhythm governed by internal biological clocks.” While people may not internally sense COVID-19’s direct impact on the heart, he adds that “heart rate is a vital sign that gives a picture of overall health.”
Among the total of 2,164 participants who enrolled in the student study, 72 undergraduate and graduate students contracted COVID-19, providing wearable data from 50 days before symptom onset to 14 days after. The researchers also analyzed this type of data for 43 medical interns from the Intern Health Study by the Michigan Neuroscience Institute and 29 individuals (who are not affiliated with the university) from the publicly available dataset.
Participants could wear the device on either wrist. They also documented their COVID-19 symptoms, such as fever, shortness of breath, cough, runny nose, vomiting, diarrhea, body aches, loss of taste, loss of smell, and sore throat.
Experts not involved in the study found the research to be productive. “This work is pioneering and reveals exciting new insights into the many important ways that we can derive clinically significant information about disease progression from consumer-grade wearable devices,” says Lisa A. Marsch, director of the Center for Technology and Behavioral Health and a professor in the Geisel School of Medicine at Dartmouth College. “Heart-rate data are among the highest-quality data that can be obtained via wearables.”
Beyond the heart, she adds, “Wearable devices are providing novel insights into individuals’ physiology and behavior in many health domains.” In particular, “this study beautifully illustrates how digital-health methodologies can markedly enhance our understanding of differences in individuals’ experience with disease and health.”
Previous studies had demonstrated that COVID-19 affects cardiovascular functions. Capitalizing on this knowledge, the University of Michigan endeavor took “a giant step forward,” says Gisele Oda, a researcher at the Institute of Biosciences at the University of Sao Paulo in Brazil and an expert in chronobiology—the science of biological rhythms. She commends the researchers for developing a complex algorithm that “could extract useful information beyond the established knowledge that heart rate increases and becomes more irregular in COVID patients.”
Wearable devices open the possibility of obtaining large-scale, long, continuous, and real-time heart-rate data on people performing everyday activities or while sleeping. “Importantly, the conceptual basis of this algorithm put circadian rhythms at the center stage,” Oda says, referring to the physical, mental, and behavioral changes that follow a 24-hour cycle. “What we knew before was often based on short-time heart rate measured at any time of day,” she adds, while noting that heart rate varies between day and night and also changes with activity.
However, without comparison to a control group of people having the common flu, it is difficult to determine if the heart-rate signals are unique to COVID-19 or also occur with other illnesses, says John Torous, an assistant professor of psychiatry at Harvard Medical School who has researched wearable devices. In addition, he points to recent data showing that many wearables, which work by beaming light through the skin, may be less accurate in people with darker skin due to variations in light absorption.
While the results sound interesting, they lack the level of conclusive evidence that would be needed to transform how physicians care for patients. “But it is a good step in learning more about what these wearables can tell us,” says Torous, who is also director of digital psychiatry at Beth Israel Deaconess Medical Center, a Harvard affiliate, in Boston. A follow-up step would entail replicating the results in a different pool of people to “help us realize the full value of this work.”
It is important to note that this research was conducted in university settings during the early phases of the pandemic, with remote learning in full swing amid strict isolation and quarantine mandates in effect. The findings demonstrate that physiological monitoring can be performed using consumer-grade wearable sensors, allowing research to continue without in-person contact, says Sung Won Choi, a professor of pediatrics at the University of Michigan who is principal investigator of the student study.
“The worldwide COVID-19 pandemic interrupted a lot of activities that relied on face-to-face interactions, including clinical research,” Choi says. “Mobile technology proved to be tremendously beneficial during that time, because it allowed us to collect detailed physiological data from research participants remotely over an entire semester.” In fact, the researchers did not have any in-person contact with the students involved in the study. “Everything was done virtually," Choi explains. "Importantly, their willingness to participate in research and share data during this historical time, combined with the capacity of secure cloud storage and novel mathematical analytics, enabled our research teams to identify unique patterns in heart-rate data associated with COVID-19.”
Susan Kreimer is a New York-based freelance journalist who has followed the landscape of health care since the late 1990s, initially as a staff reporter for major daily newspapers. She writes about breakthrough studies, personal health, and the business of clinical practice. Raised in the Chicago area, she holds a B.A. in Journalism/Mass Communication and French, with minors in German and Russian, from the University of Iowa and an M.S. from the Columbia University Graduate School of Journalism.
December 23 | 2019
A New Test Aims to Objectively Measure Pain. It Could Help Legitimate Sufferers Access the Meds They Need.
Sickle cell patient Bridgett Willkie found herself being labeled an addict when she sought an opioid prescription to control her pain.
(Left photo, courtesy of Willkie; on right, photo © by steheap/Adobe)
"That throbbing you feel for the first minute after a door slams on your finger."
This is how Central Florida resident Bridgett Willkie describes the attacks of pain caused by her sickle cell anemia – a genetic blood disorder in which a patient's red blood cells become shaped like sickles and get stuck in blood vessels, thereby obstructing the flow of blood and oxygen.
"I found myself being labeled as an addict and I never was."
Willkie's lifelong battle with the condition has led to avascular necrosis in both of her shoulders, hips, knees and ankles. This means that her bone tissue is dying due to insufficient blood supply (sickle cell anemia is among the medical conditions that can decrease blood flow to one's bones).
"That adds to the pain significantly," she says. "Every time my heart beats, it hurts. And the pain moves. It follows the path of circulation. I liken it to a traffic jam in my veins."
For more than a decade, she received prescriptions for Oxycontin. Then, four years ago, her hematologist – who had been her doctor for 18 years – suffered a fatal heart attack. She says her longtime doctor's replacement lacked experience treating sickle cell patients and was uncomfortable writing her a prescription for opioids. What's more, this new doctor wanted to place her in a drug rehab facility.
"Because I refused to go, he stopped writing my scripts," she says. The ensuing three months were spent at home, detoxing. She describes the pain as unbearable. "Sometimes I just wanted to die."
One of the effects of the opioid epidemic is that many legitimate pain patients have seen their opioids significantly reduced or downright discontinued because of their doctors' fears of over-prescribing addictive medications.
"I found myself being labeled as an addict and I never was...Being treated like a drug-seeking patient is degrading and humiliating," says Willkie, who adds that when she is at the hospital, "it's exhausting arguing with the doctors...You dread them making their rounds because every day they come in talking about weaning you off your meds."
Situations such as these are fraught with tension between patients and doctors, who must remain wary about the risk of over-prescribing powerful and addictive medications. Adding to the complexity is that it can be very difficult to reliably assess a patient's level of physical pain.
However, this difficulty may soon decline, as Indiana University School of Medicine researchers, led by Dr. Alexander B. Niculescu, have reportedly devised a way to objectively assess physical pain by analyzing biomarkers in a patient's blood sample. The results of a study involving more than 300 participants were published earlier this year in the journal Molecular Psychiatry.
Niculescu – who is both a professor of psychiatry and medical neuroscience at the IU School of Medicine – explains that, when someone is in severe physical pain, a blood sample will show biomarkers related to intracellular adhesion and cell-signaling mechanisms. He adds that some of these biomarkers "have prior convergent evidence from animal or human studies for involvement in pain."
Aside from reliably measuring pain severity, Niculescu says blood biomarkers can measure the degree of one's response to treatment and also assess the risk of future recurrences of pain. He believes this new method's greatest benefit, however, might be the ability to identify a number of non-opioid medications that a particular patient is likely to respond to, based on his or her biomarker profile.
Clearly, such a method could be a gamechanger for pain patients and the professionals who treat them. As of yet, health workers have been forced to make crucial decisions based on their clinical impressions of patients; such impressions are invariably subjective. A method that enables people to prove the extent of their pain could remove the stigma that many legitimate pain patients face when seeking to obtain their needed medicine. It would also improve their chances of receiving sufficient treatment.
Niculescu says it's "theoretically possible" that there are some conditions which, despite being severe, might not reveal themselves through his testing method. But he also says that, "even if the same molecular markers that are involved in the pain process are not reflected in the blood, there are other indirect markers that should reflect the distress."
Niculescu expects his testing method will be available to the medical community at large within one to three years.
Willkie says she would welcome a reliable pain assessment method. Well-aware that she is not alone in her plight, she has more than 500 Facebook friends with sickle cell disease, and she says that "all of their opioid meds have been restricted or cut" as a result of the opioid crisis. Some now feel compelled to find their opioids "on the streets." She says she personally has never obtained opioids this way. Instead, she relies on marijuana to mitigate her pain.
Niculescu expects his testing method will be available to the medical community at large within one to three years: "It takes a while for things to translate from a lab setting to a commercial testing arena."
In the meantime, for Willkie and other patients, "we have to convince doctors and nurses that we're in pain."
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Ray Cavanaugh is a freelance writer from Massachusetts. He enjoys very long walks, stopping occasionally to indulge in his Kindle Paperwhite.
Some people can eat red meat without negative health consequences, which may be due to variability between people's gut microbes.
(Photo by Sander Dalhuisen on Unsplash)
In different countries' national dietary guidelines, red meats (beef, pork, and lamb) are often confined to a very small corner. Swedish officials, for example, advise the population to "eat less red and processed meat". Experts in Greece recommend consuming no more than four servings of red meat — not per week, but per month.
"Humans 100% rely on the microbes to digest this food."
Yet somehow, the matter is far from settled. Quibbles over the scientific evidence emerge on a regular basis — as in a recent BMJ article titled, "No need to cut red meat, say new guidelines." News headlines lately have declared that limiting red meat may be "bad advice," while carnivore diet enthusiasts boast about the weight loss and good health they've achieved on an all-meat diet. The wildly successful plant-based burgers? To them, a gimmick. The burger wars are on.
Nutrition science would seem the best place to look for answers on the health effects of specific foods. And on one hand, the science is rather clear: in large populations, people who eat more red meat tend to have more health problems, including cardiovascular disease, colorectal cancer, and other conditions. But this sort of correlational evidence fails to settle the matter once and for all; many who look closely at these studies cite methodological shortcomings and a low certainty of evidence.
Some scientists, meanwhile, are trying to cut through the noise by increasing their focus on the mechanisms: exactly how red meat is digested and the step-by-step of how this affects human health. And curiously, as these lines of evidence emerge, several of them center around gut microbes as active participants in red meat's ultimate effects on human health.
Dr. Stanley Hazen, researcher and medical director of preventive cardiology at Cleveland Clinic, was one of the first to zero in on gut microorganisms as possible contributors to the health effects of red meat. In looking for chemical compounds in the blood that could predict the future development of cardiovascular disease, his lab identified a molecule called trimethylamine-N-oxide (TMAO). Little by little, he and his colleagues began to gather both human and animal evidence that TMAO played a role in causing heart disease.
Naturally, they tried to figure out where the TMAO came from. Hazen says, "We found that animal products, and especially red meat, were a dietary source that, [along with] gut microbes, would generate this product that leads to heart disease development." They observed that the gut microbes were essential for making TMAO out of dietary compounds (like red meat) that contained its precursor, trimethylamine (TMA).
So in linking red meat to cardiovascular disease through TMAO, the surprising conclusion, says Hazen, was that, "Without a doubt, [the microbes] are the most important aspect of the whole pathway."
"I think it's just a matter of time [before] we will have therapeutic interventions that actually target our gut microbes, just like the way we take drugs that lower cholesterol levels."
Other researchers have taken an interest in different red-meat-associated health problems, like colorectal cancer and the inflammation that accompanies it. This was the mechanistic link tackled by the lab of professor Karsten Zengler of the UC San Diego Departments of Pediatrics and Bioengineering—and it also led straight back to the gut microbes.
Zengler and colleagues recently published a paper in Nature Microbiology that focused on the effects of a red meat carbohydrate (or sugar) called Neu5Gc.
He explains, "If you eat animal proteins in your diet… the bound sugars in your diet are cleaved off in your gut and they get recycled. Your own cells will not recognize between the foreign sugars and your own sugars, because they look almost identical." The unsuspecting human cells then take up these foreign sugars — spurring antibody production and creating inflammation.
Zengler showed, however, that gut bacteria use enzymes to cleave off the sugar during digestion, stopping the inflammation and rendering the sugar harmless. "There's no enzyme in the human body that can cleave this [sugar] off. Humans 100% rely on the microbes to digest this food," he says.
Both researchers are quick to caution that the health effects of diet are complex. Other work indicates, for example, that while intake of red meat can affect TMAO levels, so can intake of fish and seafood. But these new lines of evidence could help explain why some people, ironically, seem to be in perfect health despite eating a lot of red meat: their ideal frequency of meat consumption may depend on their existing community of gut microbes.
"It helps explain what accounts for inter-person variability," Hazen says.
These emerging mechanisms reinforce overall why it's prudent to limit red meat, just as the nutritional guidelines advised in the first place. But both Hazen and Zengler predict that interventions to buffer the effects of too many ribeyes may be just around the corner.
Zengler says, "Our idea is that you basically can help your own digestive system detoxify these inflammatory compounds in meat, if you continue eating red meat or you want to eat a high amount of red meat." A possibly strategy, he says, is to use specific pre- or probiotics to cultivate an inflammation-reducing gut microbial community.
Hazen foresees the emergence of drugs that act not on the human, but on the human's gut microorganisms. "I think it's just a matter of time [before] we will have therapeutic interventions that actually target our gut microbes, just like the way we take drugs that lower cholesterol levels."
He adds, "It's a matter of 'stay tuned', I think."
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Kristina Campbell is a Canadian writer who covers microbiome science for digital and print media around the world. She is author of The Well-Fed Microbiome Cookbook (Rockridge Press, 2016) and co-author of an academic textbook for health professionals, Gut Microbiota: Interactive Effects on Nutrition and Health (Elsevier, 2018).