Associations Of Visceral Adipose Tissue With Chronological And BrainAge

Abstract

New analytic approaches that leverage machine learning have been developed to assess biological brain age (BrainAge), as opposed to chronological age. The difference between chronological age and BrainAge (Brain Predicted Age Difference [BPAD]) may be an important health indicator, which invites exploration of factors associated with variation in BPAD. While adipose tissue in general, and visceral adipose tissue (VAT) in particular, has been associated with numerous chronic diseases and adverse outcomes in some specific brain structures, to our knowledge there has been no exploration of the relationship between VAT and BPAD. PURPOSE: To explore the associations of chronological age, BrainAge, and BPAD with VAT in older adults (65-85 yrs). METHODS: Healthy women (n = 404) and men (n = 149), mean age 72 ± 5 yrs, were assessed for VAT by Dual X-Ray Absorptiometry and received a structural MRI scan processed using the BrainAgeR algorithm developed by Cole et al (2018) using voxel-based features from a training sample of adults (n = 3377) aged 18-92, to derive BrainAge. Pearson correlation was used to assess associations between VAT and both chronological age and BrainAge, and linear regression was utilized to further assess the association between VAT and BPAD, adjusted for chronological age, sex, and physical activity. RESULTS: VAT was significantly associated with BrainAge (r(551) = 0.133 p < 0.002) but not chronological age (r(551) = 0.004 p = 0.460). VAT significantly predicted BPAD after adjusting for sex, chronological age, and physical activity (p = .001) with each unit of increase of VAT predicting a 0.99 year difference in BPAD (indicating an older than chronological age brain) as shown in Table 1.CONCLUSION: Higher VAT mass was associated with more advanced brain age as determined by the BrainAgeR technique. Future research should determine if changes in VAT deposition may positively affect brain structure in older adults.