Pulse Pressure Impairs Cognition via White Matter Disruption

Area of Science:

• Neuroscience
• Cardiovascular Health
• Gerontology

Background:

• Elevated pulse pressure is linked to cognitive decline in older adults.
• Mechanisms linking pulse pressure to brain damage are not fully understood.
• Hypothesis: Pulse pressure disrupts white matter microstructure, affecting cognition independently of other risks.

Purpose of the Study:

• To investigate the relationship between pulse pressure and white matter microstructure.
• To determine if white matter integrity mediates the effect of pulse pressure on cognitive processing speed.
• To explore the impact of vascular changes on higher cognitive functions.

Main Methods:

• Cross-sectional study of 708 adults (aged 18-88).
• Assessed pulse pressure, blood pressure, and heart rate variability.
• Used diffusion-weighted imaging to measure white matter microstructure (peak width of skeletonized mean diffusivity - PSMD).
• Evaluated cognitive function using processing speed tests.

Main Results:

• Higher pulse pressure correlated with disrupted white matter microstructure (PSMD).
• Disrupted white matter was associated with slower processing speed.
• PSMD mediated 72% of the effect of pulse pressure on processing speed, independent of age and other cardiovascular factors.
• Vascular changes in processing speed influenced higher cognitive functions.

Conclusions:

• High pulse pressure impairs white matter integrity, leading to cognitive processing deficits.
• Managing pulse pressure is crucial for maintaining white matter integrity and preventing cognitive decline.
• Findings highlight the link between vascular health and cognitive function across the lifespan.