Autonomic Cardiac Function in Preclinical Alzheimer's Disease

Area of Science:

• Neuroscience
• Cardiology
• Gerontology

Background:

• Alzheimer's disease (AD) is a progressive neurodegenerative disorder.
• Early detection of AD biomarkers is crucial for timely intervention.
• Autonomic cardiac function may reflect early neurological changes.

Purpose of the Study:

• To investigate early autonomic cardiac changes in pre-clinical Alzheimer's disease.
• To assess the relationship between cortical amyloid accumulation and vagal tone.
• To evaluate electrocardiographic measures of vagal tone in adults at risk for AD.

Main Methods:

• Sixty-three adults (ages 55-75) with AD risk factors were studied.
• Electrocardiographic measures of vagal tone were recorded at rest and during cognitive testing.
• Amyloid Positron Emission Tomography (PET) scans (18F-Florbetapir) determined amyloid positivity (Aβ+).

Main Results:

• No significant changes in electrocardiographic measures were observed for amyloid-positive (Aβ+) participants.
• Amyloid-negative (Aβ-) subjects exhibited an expected increase in vagal tone during cognitive stress.
• These findings suggest a dissociation in cardiac autonomic response based on amyloid status.

Conclusions:

• Cortical amyloid accumulation, a precursor to AD, may be linked to altered autonomic cardiac function.
• Vagal tone modulation during cognitive stress appears impaired in individuals with preclinical AD pathology.
• These results highlight the potential of cardiac autonomic measures as early indicators in AD research.