Summary: Healthy hearts show complex, adaptive rhythms that reflect resilience to internal and external changes. Researchers applied a novel method to analyze heart rate complexity using wearable pulse oximeters and found that greater complexity predicted slower cognitive decline in older adults.
This new measure was more sensitive than traditional heart rate variability in forecasting cognitive changes. The findings, drawn from data on participants averaging 82 years of age, suggest that heartbeat complexity could serve as a noninvasive biomarker for brain health.
Key Facts:
- Novel Heart Measure: Greater heartbeat complexity predicted slower cognitive decline, outperforming conventional heart rate variability metrics.
- Wearable Tech: Pulse rate data was collected noninvasively overnight using wearable fingertip pulse oximeters.
- Potential for Early Detection: The method may help identify individuals at higher dementia risk before symptoms emerge.
Source: Mass General
Healthy hearts are adaptable, and heartbeats exhibit complex variation as they adjust to tiny changes in the body and environment.
Mass General Brigham researchers have applied a new way to measure the complexity of pulse rates, using data collected through wearable pulse oximetry devices.
The new method, published in Journal of the American Heart Association, provides a more detailed peek into heart health than traditional measures, uncovering a link between reduced complexity and future cognitive decline.
“Heart rate complexity is a hallmark of healthy physiology,” said senior author Peng Li, PhD, of the Department of Anesthesia, Critical Care and Pain Medicine at Massachusetts General Hospital (MGH) and the Division of Sleep and Circadian Disorders at Brigham and Women’s Hospital (BWH), both founding members of the Mass General Brigham healthcare system.
“Our hearts must balance between spontaneity and adaptability, incorporating internal needs and external stressors.”
The study used data from 503 participants (average age 82, 76% women) in the Rush Memory and Aging Project.
The researchers analyzed overnight pulse rate measurements—collected by a fingertip pulse oximetry device known as the Itamar WatchPAT 300 device—and comprehensive measures of cognitive functions, collected around the same time as the pulse rate measurement and at least one annual follow-up visit up to 4.5 years later.
The team found that people with greater complexity in their heartbeats at baseline tend to experience slower cognitive decline over time. They determined that the conventional measures of heart rate variability did not predict this effect, indicating their measure was more sensitive in capturing heart functions predictive of cognitive decline.
The researchers plan to investigate whether pulse rate complexity can predict development of dementia, which would make it useful for identifying people at an early stage who might benefit from therapeutic interventions.
“The findings underscore the usefulness of our approach as a noninvasive measure for how flexible the heart is in responding to nervous system cues,” said lead author Chenlu Gao, PhD, also in the Department of Anesthesia, Critical Care and Pain Medicine at MGH.
“It is suitable for future studies aimed at understanding the interplay between heart health and cognitive aging.”
Authorship: In addition to Gao and Li, Mass General Brigham authors include Shahab Haghayegh, Ruixue Cai, Lei Gao, and Kun Hu. Additional authors include Andrew S.P. Lim, Jingyun Yang, Lei Yu, Agustin Ibanez, Aron S. Buchman, and David A. Bennett.
Disclosures: Li has received a monetary gift to support research from iFutureLab, serves on the iFutureLab-HEKA Scientific Advisory Board as the Chair of Cardiac Dynamics and Honorary Life-Time Co-Founder and has received consulting fees, has received honorarium for lecturing from China Pharmaceutical University.
Hu serves on the iFutureLab-HEKA Scientific Advisory Board as the Chair of Medical Biodynamics and Honorary Life-Time Co-Founder and has received consulting fees.
Funding: This work was supported by the BrightFocus Foundation (A2020886S). The Rush Memory and Aging Project is supported by NIH (R01AG17917, R01AG052488).
About this cardiovascular function and cognition research news
Author: Brandon Chase
Source: Mass General
Contact: Brandon Chase – Mass General
Image: The image is credited to Neuroscience News
Original Research: Open access.
“Reduced complexity of pulse rate is associated with faster cognitive decline in older adults” by Peng Li et al. Journal of the American Heart Association
Abstract
Reduced complexity of pulse rate is associated with faster cognitive decline in older adults
Background
Cardiovascular diseases are closely linked to cognitive health. Subclinical cardiovascular functional changes, such as cardiac autonomic dysfunction, precede cardiovascular diseases and improve risk stratification.
Continuous monitoring of heart rate or pulse rate is a commonly used approach to evaluate cardiac cycle and autonomic regulation. We investigated whether the complexity of pulse rate is associated with longitudinal cognitive decline in older adults.
Methods
Overnight pulse oximetry data were collected from 503 participants (mean age=82±7 [SD] years, 76% female). We used a previously established distribution entropy algorithm to extract the complexity of pulse rate as a proxy for subclinical cardiovascular function. Participants completed a standardized cognitive test battery during the same visit of pulse oximetry and at least 1 follow‐up visit.
Linear mixed‐effects models were conducted to test whether distribution entropy is associated with longitudinal changes in global cognition and separately, in 5 cognitive domains.
Results
Greater distribution entropy (ie, better complexity) was associated with a slower decline in global cognition; the effect of 1‐SD increase in distribution entropy was equivalent to being approximately 3 years younger. No associations were observed between conventional time‐ or frequency‐domain pulse rate variability measures and cognitive changes.
Conclusions
Higher complexity of pulse rate is linked with slower cognitive decline in older adults. Future studies should test whether complexity is also associated with future risks of neurodegenerative disorders, such as dementia, and further elucidate the causal directions.
