Cardiorespiratory fitness diminishes the effects of age on white matter hyperintensity volume.

Nathan F Johnson,Ahmed A Bahrani,David K Powell,Gregory A Jicha,Brian T Gold,Diane K Ehlers

doi:10.1371/journal.pone.0236986

Nathan F Johnson, Ahmed A Bahrani + Show 4 more

Open Access

https://doi.org/10.1371/journal.pone.0236986

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Journal: PloS one	Publication Date: Aug 31, 2020
Citations: 12	License type: CC BY 4.0

Affiliation: University of Kentucky, University of Baghdad

Abstract

White matter hyperintensities (WMHs) are among the most commonly observed marker of cerebrovascular disease. Age is a key risk factor for WMH development. Cardiorespiratory fitness (CRF) is associated with increased vessel compliance, but it remains unknown if high CRF affects WMH volume. This study explored the effects of CRF on WMH volume in community-dwelling older adults. We further tested the possibility of an interaction between CRF and age on WMH volume. Participants were 76 adults between the ages of 59 and 77 (mean age = 65.36 years, SD = 3.92) who underwent a maximal graded exercise test and structural brain imaging. Results indicated that age was a predictor of WMH volume (beta = .32, p = .015). However, an age-by-CRF interaction was observed such that higher CRF was associated with lower WMH volume in older participants (beta = -.25, p = .040). Our findings suggest that higher levels of aerobic fitness may protect cerebrovascular health in older adults.

Highlights

White matter (WM) hyperintensities (WMHs) are one of the most ubiquitous age-related structural changes observed on T2-weighted MRI, yet they are of unknown etiology and have multiple histological correlates [1]
mean arterial pressure (MAP), Cardiorespiratory fitness (CRF) and the MAP-CRF interaction term were not independent predictors White matter hyperintensities (WMHs) volume when controlling for age
Our results indicate a significant age-by-fitness interaction on WMH volume in older adults

Summary

Introduction

White matter (WM) hyperintensities (WMHs) are one of the most ubiquitous age-related structural changes observed on T2-weighted MRI, yet they are of unknown etiology and have multiple histological correlates [1]. The physiologic antecedents of WMHs are heterogenous [1,2,3], but many are presumed to be a consequence of age-related vascular changes [4, 5]. CRF may attenuate the development of WMHs in older adults. We hypothesized that fitness level may modify the relationship between age and WMH volume. We predicted that the effects of age on WMH volume may be less pronounced in individuals with high fitness levels based on our hypothesis that CRF may attenuate the age-related acceleration of WMH load. Our hypothesis was developed based on reports that higher levels of physical activity are associated with less WMHs [34,35,36]

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