Association Between Visceral Fat and Brain Cortical Thickness in the Elderly: A Neuroimaging Study

Abstract

BackgroundDespite emerging evidence suggesting that visceral fat may play a major role in obesity-induced neurodegeneration, little evidence exists on the association between visceral fat and brain cortical thickness in the elderly.PurposeWe aimed to examine the association between abdominal fat and brain cortical thickness in a Korean elderly population.MethodsThis cross-sectional study included elderly individuals without dementia (n = 316). Areas of visceral fat and subcutaneous fat (cm2) were estimated from computed tomography scans. Regional cortical thicknesses (mm) were obtained by analyzing brain magnetic resonance images. Given the inverted U-shaped relationship between visceral fat area and global cortical thickness (examined using a generalized additive model), visceral fat area was categorized into quintiles, with the middle quintile being the reference group. A generalized linear model was built to explore brain regions associated with visceral fat. The same approach was used for subcutaneous fat.ResultsThe mean (standard deviation) age was 67.6 (5.0) years. The highest quintile (vs. the middle quintile) group of visceral fat area had reduced cortical thicknesses in the global [β = –0.04 mm, standard error (SE) = 0.02 mm, p = 0.004], parietal (β = –0.04 mm, SE = 0.02 mm, p = 0.01), temporal (β = –0.05 mm, SE = 0.02 mm, p = 0.002), cingulate (β = –0.06 mm, SE = 0.02 mm, p = 0.01), and insula lobes (β = –0.06 mm, SE = 0.03 mm, p = 0.02). None of the regional cortical thicknesses significantly differed between the highest and the middle quintile groups of subcutaneous fat area.ConclusionThe findings suggest that a high level of visceral fat, but not subcutaneous fat, is associated with a reduced cortical thickness in the elderly.

Associations between abdominal adipose tissue, reproductive span, and brain characteristics in post-menopausal women

“…The associations between abdominal adipose tissue and brain characteristics are consistent with previous studies linking elevated adipose tissue to older brain age (Beck et al, 2022;Subramaniapillai et al, 2022), lower brain volume (Cho et al, 2021;Debette & Markus, 2010;Gurholt et al, 2021;Isaac et al, 2011;Veit et al, 2014), and higher WMH load (Arnoldussen et al, 2019;Lampe et al, 2019;Park et al, 2018;Vuorinen et al, 2014). The relationships were strongest for WMH volume, suggesting that brain white matter may be particularly sensitive to elevated abdominal adipose tissue in post-menopausal females.…”

“…The association with brain characteristics did not differ between the two abdominal adipose tissue types. VAT and ASAT have distinct anatomical, cellular, molecular, physiological, clinical and prognostic correlates (Ibrahim, 2010;Kwok et al, 2016), and previous studies have consistently linked midlife VAT to more adverse effects on brain structure compared to ASAT (Anand et al, 2022;Cho et al, 2021;Kim et al, 2017;Nam et al, 2019;Zsido et al, 2019). In the current sample, VAT and ASAT levels were highly correlated and showed similar associations with the brain measures.…”

“…Studies utilising magnetic resonance imaging (MRI) of the body, which allows for more precise measures of fat distribution than conventional anthropomorphic methods (Borga et al, 2018), demonstrate that visceral adipose tissue (VAT; the fat surrounding the ab-dominal organs) increases more following menopause than abdominal subcutaneous adipose tissue (ASAT; the fat below the skin) (Lee et al, 2009;Leeners et al, 2017;Lovejoy et al, 2008;Samargandy et al, 2021). Consistent evidence shows that higher midlife VAT in both males and females is associated with lower cortical and total brain volume (Cho et al, 2021;Debette & Markus, 2010;Isaac et al, 2011;Veit et al, 2014), higher WMH load (Anand et al, 2022;Kim et al, 2017;Pasha et al, 2017), and accelerated brain ageing (Zsido et al, 2019), while ASAT is found to be significantly less detrimental or even protective for brain volume (Cho et al, 2021) and WMH load (Kim et al, 2017), especially in females (Nam et al, 2019). However, differences in how VAT and ASAT levels relate to various brain characteristics in post-menopausal females have not been directly assessed.…”

Bidirectional communication between brain and visceral white adipose tissue: Its potential impact on Alzheimer's disease

“… 23 In the elderly, the larger area of vWAT was accompanied with the reduced cortical thickness of global, parietal, temporal, cingulate and insula lobe. 24 …”

“…The decreased cortical thickness Negatively The elderly 316 The area of vWAT vs. The cortical thickness of global, parietal, temporal, cingulate and insula lobe Negatively Cross-sectional study 24 Community-dwelling healthy older population 1209 The volume ratio of the thigh muscle to vWAT vs. The volume of temporal lobe and cerebellum Positively Prospective study 25 The thigh muscle/vWAT volume ratio vs.…”