A new study involving over 4,000 participants found that heart rate variability during sleep may signal future neurologic and psychiatric disorders, including stroke and depression, according to research presented at the 11th Congress of the European Academy of Neurology.
Investigators from a Swiss university hospital presented findings from the Bernese Sleep-Wake Registry, focusing on 4,170 adults (age = 48 ± 19 years) who underwent overnight sleep studies. Participants were followed over time and contributed more than 13,000 person-years of observation.
The researchers aimed to determine whether specific sleep patterns were linked to the development of medical conditions. They examined two types of data that were collected during sleep: sleep macroarchitecture and heart rate variability (HRV). Sleep macroarchitecture refers to the structure of sleep—such as time spent in different stages—while HRV measures the variation in time between heartbeats and reflects autonomic nervous system function, which regulates involuntary functions like heart rate and respiration.
Thirty-six health conditions that occurred during and after the sleep studies were grouped into eight categories: neurologic, psychiatric, cardiovascular, metabolic, endocrine, pulmonary, musculoskeletal, and gastrointestinal.
HRV patterns showed stronger associations with future disease than sleep macroarchitecture. Neurologic conditions, such as stroke, were linked to high and complex HRV. Psychiatric conditions, primarily depression, were associated with low HRV and reduced variability.
Sleep macroarchitecture showed fewer associations with future health outcomes. An exception was sleep-disordered breathing, which was linked to higher risks for cardiovascular, endocrine, and metabolic diseases, and was consistent with known associations between sleep apnea and chronic conditions such as hypertension and diabetes.
Metabolic disorders were also associated with high HRV, particularly in the very low-frequency range, a measure that may capture different aspects of autonomic activity than other HRV components.
All statistical models were adjusted for age and sex to control for demographic factors.
The investigators noted that HRV may serve as an early marker for identifying patients who are at higher risk of neurologic and psychiatric conditions. However, additional studies are needed to assess its clinical application.
With growing interest in sleep’s role in overall health, the findings support the value of monitoring autonomic activity during sleep. Future research will further examine sleep microarchitecture, including brain wave patterns, to understand how sleep influences long-term health outcomes.
The authors reported no conflicts of interest.