Understanding Cerebral Blood Flow Dynamics for Alzheimer's Disease Prevention Through Acute Exercise (flADex):...

Area of Science:

• Neuroscience
• Exercise Physiology
• Biochemistry

Background:

• Alzheimer's disease (AD) is a major global health concern, with early alterations in cerebral blood flow (CBF) and blood biomarkers being critical.
• While exercise shows potential in delaying AD progression, the underlying mechanisms for its brain health benefits remain unclear.
• The flADex study protocol is designed to investigate the acute physiological responses to different exercise modalities in older adults.

Purpose of the Study:

• To examine the acute effects of moderate-intensity aerobic and resistance exercise on cerebral blood flow (CBF) in older adults.
• To assess the impact of different exercise types on key Alzheimer's disease (AD) blood biomarkers and neurodegenerative markers.
• To explore potential correlations between exercise-induced changes in CBF, biomarkers, and cognitive/mood status.

Main Methods:

• A counterbalanced crossover trial involving 20 older adults (68-83 years) with negative amyloid status and APOEε4 non-carrier status.
• Participants completed 30-minute sessions of moderate-intensity aerobic exercise, resistance exercise, or rest in a randomized order.
• Cerebral blood flow (CBF) was measured using pseudo-continuous arterial spin labeling MRI, with blood biomarkers analyzed via blood samples at multiple timepoints.

Main Results:

• Aerobic exercise demonstrated greater acute effects on CBF dynamics compared to resistance exercise and rest.
• Significant fluctuations in AD pathology and neurodegeneration biomarkers (e.g., Aβ42, p-tau217) were observed post-exercise.
• Preliminary findings suggest differential regional CBF responses and dynamic biomarker changes following exercise interventions.

Conclusions:

• The study provides insights into the acute vascular and molecular effects of different exercise types on pathways relevant to Alzheimer's disease.
• Aerobic exercise appears more effective than resistance exercise in acutely modulating CBF and certain AD biomarkers.
• Results may inform standardized blood sampling protocols for improved diagnostic accuracy and guide exercise recommendations for brain health.