Associations between age and gray matter volume in anatomical brain networks in middle‐aged to older adults

Anne Hafkemeijer,Jeroen Van Der Grond,Irmhild Altmann‐Schneider,Anton J M De Craen,P Eline Slagboom,Serge A R B Rombouts

doi:10.1111/acel.12271

Anne Hafkemeijer, Jeroen Van Der Grond + Show 4 more

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https://doi.org/10.1111/acel.12271

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Abstract

Aging is associated with cognitive decline, diminished brain function, regional brain atrophy, and disrupted structural and functional brain connectivity. Understanding brain networks in aging is essential, as brain function depends on large-scale distributed networks. Little is known of structural covariance networks to study inter-regional gray matter anatomical associations in aging. Here, we investigate anatomical brain networks based on structural covariance of gray matter volume among 370 middle-aged to older adults of 45–85 years. For each of 370 subjects, we acquired a T1-weighted anatomical MRI scan. After segmentation of structural MRI scans, nine anatomical networks were defined based on structural covariance of gray matter volume among subjects. We analyzed associations between age and gray matter volume in anatomical networks using linear regression analyses. Age was negatively associated with gray matter volume in four anatomical networks (P < 0.001, corrected): a subcortical network, sensorimotor network, posterior cingulate network, and an anterior cingulate network. Age was not significantly associated with gray matter volume in five networks: temporal network, auditory network, and three cerebellar networks. These results were independent of gender and white matter hyperintensities. Gray matter volume decreases with age in networks containing subcortical structures, sensorimotor structures, posterior, and anterior cingulate cortices. Gray matter volume in temporal, auditory, and cerebellar networks remains relatively unaffected with advancing age.

Highlights

It is well recognized that the process of aging is associated with cognitive decline and diminished brain function (Grady, 2012)
Our aim was to investigate whole-brain anatomical networks to explore which networks are associated with the process of healthy aging and which networks do not show an age association
We identified anatomical brain networks based on structural covariance of gray matter volume in a large sample of healthy participants aged between 45 and 85 years

Summary

Introduction

It is well recognized that the process of aging is associated with cognitive decline and diminished brain function (Grady, 2012). Numerous neuroimaging studies have unequivocally shown that aging is associated with loss of brain tissue, in which process especially the gray matter seems affected. Volumetric and morphometric neuroimaging studies have demonstrated a consistent age-dependent decrease in regional gray matter volume, mainly expressed in the temporal lobe and hippocampus, the cingulate cortex, and prefrontal regions (Good et al, 2001; Jernigan et al, 2001; Resnick et al, 2003; Raz et al, 2005). It has been shown that functional connectivity decreases with age, especially connectivity in the default mode network between the medial prefrontal cortex, anterior and posterior cingulate cortex, precuneus, parietal cortex, and hippocampus (Damoiseaux et al, 2008; Hafkemeijer et al, 2012; Ferreira & Busatto, 2013). Aging is associated with disrupted white matter anatomical connections, in the frontal white matter, anterior cingulum, and the genu of the corpus callosum (Salat et al, 2005; Madden et al, 2012)

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