Patients with lower heart rate variability during sleep may suffer from insomnia, the study found.
A new report links heart rate variability (HRV) with risk of insomnia and used a novel tool for identifying patients who may be suffering from insomnia — their beds.
The study, which was presented in March at the World Sleep Conference, in Rome, found patients with insomnia tended to have lower HRV. However, it also showed that so-called “smart beds” that are equipped with sensors and other technology to track people’s physiological and sleep pattern can produce meaningful health insights for and about the people who sleep in them.
In the new report, investigators compared physiological sleep data in 12 healthy controls and 9 people with insomnia. They examined rapid eye movement (REM) and non-REM sleep, electroencephalogram (EEG) metrics, and HRV (as measured by echocardiogram [ECG]) to see whether there might be that would help physicians better understand or diagnose insomnia.
Co-author Gary Garcia-Molina, Ph.D., the senior principal scientist at Sleep Number Corporation, which is headquartered in Minneapolis, told Managed Healthcare Executive®that sleep disorders disrupt the way the brain operates and affects the regulation of bodily functions such as breathing, heart rate, and blood pressure. Sleep Number’s 360 smart beds are equipped with technology that gathers biometric and sleep data points. Garcia-Molina and his co-author, Shawn Barr, Ph.D., wanted to know whether those data might help indicate signals that a patient might be suffering from a sleep disorder.
The data pointed to HRV, suggesting that low variability in heart rate during sleep could be a sign of insomnia.
Garcia-Molina explained that in healthy patients, HRV is low during waking hours, but significantly higher during sleep. “In insomnia, that distinction [between waking and sleeping HRV] is not as clear and suggests that sleep in an insomnia patient is shallower and not as restorative as that of healthy individuals,” he said.
The findings are based on a small sample size, and Garcia-Molina said further study is warranted to see whether the results could be replicated in a larger cohort. However, he said the study points to the utility of data from smart devices to detect sleep problems that might otherwise go unnoticed.
For now, such data will not replace formal sleep studies in laboratories, but Garcia-Molina said they do offer something those sleep studies do not — accurate longitudinal context to support sleep disorder diagnoses. Moreover, he pointed to a recently published study suggesting that sleep data collected by the bed correlates strongly with data from formal polysomnography. In the future, he said advancements in data collection and analysis will be able to provide users with advanced sleep monitoring and personalized health insights, he said.
The insomnia study is just one area of research for Sleep Number, which also presented data suggesting the bed can help identify symptoms of respiratory illnesses such as influenza and COVID-19.
The stock price of Sleep Number Corporation ($SNBR) was over $142 a share in March 2021, but it has slid since. Today it was trading at about $51 a share.