How Patients With Chronic Diseases “Hack” Their Wearable Devices

Although finding an answer took years and dozens of doctor visits and tests, this change in resting heart rate was one of the first clues that I had developed a form of dysautonomia called orthostatic tachycardia syndrome. postural.

Wearable technology, such as Fitbit, Apple Watch, Oura Ring, Whoop, or a number of other commercially available devices, provides a convenient way to collect personal data about our health trends, whether is information about resting heart rate, heart rate variability, sleep duration or total activity levels.

What’s less clear is what all that data means, especially when certain readings are unusual or a person is struggling with symptoms they don’t have a diagnosis for. “What we have now is a health and wellness industry that provides data-driven insights and advice, as long as their physiology is typical,” says Mount Sinai physical therapy researcher David Putrino. At New York. “What is critically needed is to apply these same principles to groups of people with complex chronic diseases who have atypical physiology.”

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At the moment, many patients with chronic conditions resort to setting up a system that works for them, based on their own knowledge of their condition and data that they can access using various monitoring tools. health tracking, while navigating life with chronic illness. , where symptoms fluctuate from day to day.

For many patients, this creativity was born out of desperation, as many of these illnesses, whether long Covid, dysautonomia or myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), have very few treatments available and even fewer specialists who are trained to recognize and treat them. “We’re forced to do it ourselves because the system isn’t set up to deal with these more complex, invisible conditions,” says Spencer Gudewill, a post-concussion syndrome patient and co-founder of Strong Haulers, which aims to helping people with chronic conditions manage their condition using wearable technologies. “A lot of people fall through the cracks.”

Resting heart rate as a warning sign

Resting heart rate has long been used as a measure of overall health, with average values ​​ranging between 60 and 100. People who are healthy and have a higher level of fitness tend to have lower heart rates, as their hearts are generally stronger and more efficient, with trained athletes often reporting resting heart rates below 60 beats per minute. A higher resting heart rate, or an increase over time, is often an indicator of poorer health, including a high risk of heart attack.

Short-term changes in resting heart rate are often used by athletes to assess whether they are overtraining, while the changes can also be a sign of an infection, such as the flu or Covid. In a study published in the Journal of the American Medical Association using Fitbit data, the researchers found that, on average, a Covid infection caused an increase in resting heart rate that took about 79 days to return to normal.

Although changes in resting heart rate can be a useful indicator of a person’s health, the downside is that resting heart rate tends to remain relatively stable throughout a person’s lifetime. which means that any change tends to be gradual and may take some time. to be detected as significant.

Tracking heart rate variability can offer useful insights

In the fall of 2021, when I knew something was wrong but just couldn’t convince my doctors to take me seriously, I bought an Oura ring in a fit of desperation, to wear in conjunction with my Fitbit. One of the reasons for my purchase was that it offered nightly heart rate variability tracking. In theory, heart rate variability (or HRV) could offer additional information, which could complement the changes I was already seeing in my resting heart rate, but only if I knew what to do with it.

Heart rate variability, which is the variation in timing between heartbeats, offers a complementary look at overall health, in part because it is an indirect look at how the autonomic nervous system works. ‘a person. HRV values ​​typically range from 20 to 200 milliseconds, with a higher HRV being a sign that a person’s autonomic nervous system is very reactive, whether it’s telling your heart to beat faster or slower, your blood vessels your blood to constrict or expand, or your digestion to speed up or slow down. “The extent to which your autonomic nervous system can make very small but very specific changes is an indicator that you have a healthy, highly optimized system,” Putrino says. It is this understanding of the autonomic nervous system that is often useful for patients with chronic conditions, as a lower HRV is a sign that the body is under severe stress.

The main problem with HRV tracking is that the numbers are difficult to understand, as the values ​​are highly variable, including a wide range of average values ​​from person to person, and even a large time of day variation. in hour, depending on a person’s health and environment. It is these wide ranges of values ​​that make the HRV so difficult to interpret and do not lend themselves well to annual health checks. However, when these averages are examined over time, they can provide useful information.

How patients use their wearable devices

For Tess Falor, a patient with ME/CFS, noticing an eight-month drop in average nighttime HRV led her to realize that she had taken on too many work projects, resulting in worsening of his condition. “You couldn’t really tell, because it was happening slowly,” says Falor, who co-founded the patient-led organization Remission Biome, which studies the impact of the microbiome on ME/CFS symptoms.

Falor, who has worn a FitBit regularly since 2009, also uses heart rate tracking to prevent overexertion, which can lead to debilitating accidents. She’s found that keeping her heart rate below a certain threshold helps her avoid these crashes more accurately than simply monitoring her symptoms. “Listening to my body is not enough,” says Falor.

For Ibrahim Rashid, a long-time Covid patient, combining symptom tracking with HRV led him to correlate his levels of increasing leg pain, which was sometimes so bad he needed a wheelchair, with decreasing HRV trends.

He also found that correlating his symptoms with his health data helped him make judgments about what helps manage his symptoms the most, such as limiting stress, and what has only a minimal effect, like cutting out all the sugar. “You spend so much time trying to figure out what works and what doesn’t,” says Rashid, also co-founder of Strong Haulers.

For Harry Leeming, the confusion of trying to manage his long Covid symptoms, combined with the difficulties of adapting wearable technology to his needs, was his main motivation for developing the Visible app. He is currently testing a wearable accessory that gives him information on how long he spends in an upright position, which he says correlates to the severity of his symptoms.

In my own case, the fact that my HRV was abnormally low and not responding in the usual way to lifestyle changes ended up being another clue that the underlying problem was an autonomic nervous system disorder. After months of tracking, I was also able to look at trends in average HRV and correlate periods of low HRV counts with times when my symptoms were particularly severe, my own personal early warning system for knowing when a flare major could occur. After receiving a formal diagnosis and starting treatment, which included medication and additional lifestyle changes, my symptoms began to improve, along with my average nighttime HRV. “Arguably, the signals are stronger and the data is much more actionable” for people living with chronic disease, Leeming says.