If your Apple Watch signals potential sleep apnea, comprehend its implications and follow the subsequent course of action.
Sleep obstruction is a health issue that results in a person's breathing momentarily halting when the muscles in their throat relax excessively and the airway collapses. This issue can cause loud snoring, often unnoticed by the sleeper themselves. It's typically detected first by a partner or roommate.
This condition has been connected to several health issues, mainly affecting the cardiovascular system, such as high blood pressure, strokes, heart attacks, heart failure, and heart rhythm problems like atrial fibrillation. It's also linked to dementia and daytime fatigue. Those with sleep obstruction are also at a higher risk of being involved in car accidents.
Millions of individuals are believed to suffer from this disturbed breathing condition but remain undiagnosed. Experts suggest that this new app could serve as a helpful tool to guide individuals towards medical treatment. The sleep obstruction notification is available on recent Series 10 Apple Watches and certain older models following a software update.
However, like all new technology, this sleep obstruction feature has its limitations and potential drawbacks, including giving rise to excessive anxiety and poor sleep if an individual becomes overly fixated on the data or concerned about the results.
Dr. Robson Capasso, chief of sleep surgery at the Stanford University School of Medicine, observed this trend, known as orthosomnia, which involves individuals becoming overly anxious about their sleep data and making drastic efforts to improve their sleep, such as resorting to unsafe supplements or extreme diets.
New methods of tracking sleep do not have to be stressful, however.
“I view this as a great tool, it just needs to be used correctly,” said Capasso.
Proceed with caution
The Apple Watch's new feature utilizes the device's accelerometer, which detects movement, and Apple claims it's so sensitive that it can even identify the most minute wrist movements linked to breathing during sleep.
The feature, though, requires user activation.
To diagnose sleep obstruction, the watch keeps track of breathing disturbances throughout the night over a 30-day period. If there are at least 10 sessions with pauses in breathing and at least five of these have an abnormal number of pauses, the watch sends a notification to the user.
How effective is the feature?
Apple tested the feature on nearly 1,500 participants, some with normal breathing during sleep and others with varying degrees of sleep obstruction. Each participant wore the watch for at least 30 nights and also engaged in at least two nights of a traditional home sleep study using a device that recorded a range of factors, including nasal pressure, oxygen level, body position, breathing effort, pulse, and leg movement.
Researchers used the data acquired during the home sleep study to determine each participant's apnea-hypopnea index, or the number of times per hour that breathing stops or slows down. The researchers then compared the watch's performance to the measures obtained during the sleep study.
In general, Apple's findings indicated that the watch detected any level of sleep obstruction around 66% of the time. It was more accurate at detecting severe sleep obstruction, correctly alerting users about 89% of the time. It correctly identified moderate respiratory problems approximately 43% of the time.
Apple stated that it adjusted the watch's algorithm to favor avoiding false positives, which might frighten users, and this approach appears to have been successful, as the new alert did not falsely identify normal sleepers with sleep obstruction 100% of the time.
If you receive an alert, you can have confidence that the result is authentic and warrant further evaluation with your primary care physician or a sleep specialist. Conversely, if you don't receive an alert, it doesn't necessarily rule out the possibility of sleep obstruction, particularly if you exhibit additional suspicious symptoms.
The company's research has not yet been evaluated by outside experts or published in a medical journal. However, the US Food and Drug Administration approved the marketing of the sleep obstruction feature on Apple Watches in mid-September.
There are other wearable devices that also claim to help individuals determine if they have sleep obstruction, but Apple's entry into the market has garnered some attention.
“It has come up in conversation so many times,” said Dr. Jing Wang, clinical director of the Mount Sinai Integrative Sleep Center. “I have become more aware of it.”
The watch versus a sleep specialist
Wang noted that the watch's methodology differs from her diagnostic process. The watch relies on wrist movements, whereas Wang starts with symptoms.
“Other than the watch saying this, or other than your tracker saying this, what else have you experienced?” Wang asked.
The watch does not inquire about symptoms. It also does not employ the pulse oxygen feature, which has disappeared from some Apple watches due to an ongoing patent dispute.
Wang mentioned that common indicators of sleep obstruction include loud snoring (though not all snorers have obstruction), a partner complaining about the noise and reporting difficulty sleeping due to it, a patient reporting waking up choking or gasping, and individuals who mention feeling tired or exhausted during the day. Morning headaches, high blood pressure, and memory issues are also possible symptoms, according to Wang.
Following this consultation, she would order a sleep study if she suspects it's necessary. These can be conducted at home or in a sleep lab, which usually requires an overnight stay at a hospital or sleep center. Sleep studies record multiple variables, including blood oxygen, respiratory rate, pauses in breathing, and nighttime awakenings.
The Apple Watch possesses certain abilities, yet the company neglected to consider these capabilities when developing the sleep apnea feature. If they had, they might have been more effective in identifying mild and moderate cases of apnea, suggests Dr. Eric Topol, a cardiologist and founder of the Scripps Translational Research Institute.
When the watch incorporated pulse oximetry, which is now defunct, it could have provided valuable data, particularly for individuals not of color, according to Topol. This is because studies have highlighted that pulse oximeters, which measure oxygen saturation, are less accurate in individuals with darker skin tones. Consequently, there's been a push for devices that are tested on a more diverse population.
The Apple Watch's algorithm, unlike home tests or sleep labs, relies on accelerometer measurements of movement, which explains its lower sensitivity.
It might not be a bad thing that the watch has a low sensitivity, argued Stanford's Capasso.
Even with comprehensive sleep studies, answers aren't straightforward. The main metric of a sleep study, the apnea-hypopnea index (AHI), does not always correspond with symptoms. Furthermore, not all cases of sleep apnea necessitate treatment.
Treating Sleep Apnea
If a patient exhibits numerous instances of interrupted breathing and frequent drops in oxygen, Capasso believes they require treatment with a continuous positive airway pressure machine (CPAP). This machine is essentially a "glorified air compressor" that delivers a steady stream of air through a mask to keep the airway open during sleep.
Capasso stated that patients with frequent drops in oxygen have a closer correlation with future clinical outcomes, particularly in terms of cardiovascular outcomes.
If a patient's AHI falls within the mild to moderate category and they also exhibit daytime symptoms of sleepiness and brain fog, Capasso might suggest CPAP as well.
However, not all patients are successful with these machines. Half of those prescribed this therapy do not use it as directed, Capasso noted.
For individuals with mild apnea, other options such as weight loss and improving poor sleep hygiene may hold the key to better sleep.
In younger adults with sleep apnea who are not overweight, Capasso looks at anatomical features, like the size of their jaws and tonsils, which can be a contributing factor.
Ultimately, Capasso takes a person's age and the severity of their condition into account when deciding on the treatment approach.
Capasso believes that the Apple Watch alerts can be beneficial for individuals who live alone or have limited access to sleep studies and specialists.
“This can be quite an effective screening tool,” he said.
This sleep obstruction issue is not only linked to several health problems such as high blood pressure and heart attacks, but it can also contribute to daytime fatigue and increase the risk of car accidents. To help individuals with this condition, experts suggest using new technologies like the sleep obstruction feature on recent Apple Watches.
The Apple Watch's sleep obstruction feature can be a helpful tool in guiding individuals towards medical treatment, as it can identify potential issues by monitoring breathing disturbances during sleep and sending notifications if at least 10 sessions with pauses in breathing are detected over a 30-day period.
