Investigating the protective role of heart rate variability on the effects of aging on cerebrovascular function as estimated by optical pulse parameters

Brain health (or lack thereof) has been linked to both long-term phenomena, such as arterial stiffening, and the cumulated effects of short-term phenomena, such as resting-state heart rate variability (rsHRV). rsHRV reflects the balance between parasympathetic (vagal) and sympathetic input to the heart and is often altered in aging because of a reduced vagal role resulting in reduced cerebrovascular reactivity and, indirectly, brain tissue damage. Here we investigate these relationships using a novel approach to studying cerebrovascular reactivity based on single-trial measures of the cerebral arterial pulse measured with diffuse optical tomography (pulse-DOT) following long and short inter-beat intervals (IBIs). Data were obtained from a sample of 141 normal individuals (age range 25-75 years), in which both EKG and pulse-DOT (measured from the entire cortical mantle) were recorded for 8-10 minutes during resting-state conditions. Results indicate that pulse-DOT parameters were significantly affected by long-term factors such as age and fitness, but also, albeit to a much smaller extent, by short-term phenomena, such as the duration of the previous IBI. rsHRV mediates some of the negative effects of age on vascular function, suggesting a protective effect of the vagal system on the cerebrovasculature. However, not all indices of cerebrovascular function where moderated by rsHRV, perhaps suggesting the possible presence of other types of age effects on the brain’s vasculature. These findings can improve our understanding of how rsHRV helps protect the brain from the negative effects of aging.

Name thesis:degree_name

M.S.

Level thesis:degree_level

Thesis

Discipline thesis:degree_discipline

Psychology

Grantor

University of Illinois Urbana-Champaign

Year dc:date

2025

Author dc:creator

• Islam, Samia S

Contributors dc:contributor

• Fabiani, Monica
• Gratton, Gabriele

• diffuse optical tomography (DOT)
• pulse-DOT
• reactivity
• heart rate variability (HRV)
• within-individual differences

Statement dc:rights

• Copyright 2025 Samia Islam

Language dc:language

en

Handle dc:identifier

https://hdl.handle.net/2142/132707

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/132707