Ritobrata Bhattacharya1, Birgitta K Velthuis2, Geert Jan Biessels3, Marielle H Emmelot-Vonk4, Mirjam I Geerlings5, Ynte M Ruigrok3, Frank LJ Visseren1 and Thomas T van Sloten1 on behalf of the UCC-SMART study group
1Department of Vascular Medicine and Endocrinology, UMC Utrecht, Utrecht, the Netherlands. 2Department of Radiology, UMC Utrecht, Utrecht, the Netherlands. 3Department of Neurology, UMC Utrecht, Utrecht, the Netherlands. 4Department of Geriatrics, UMC Utrecht, Utrecht, the Netherlands. 5Department of General Practice, Amsterdam UMC, the Netherlands.
Background: Dementia is a growing global health concern and increasingly linked to vascular risk factors, including adiposity. However, the relation between adipose tissue distribution and cognitive decline and structural brain changes remains unclear. This study quantified the relation between various adiposity measures reflecting visceral adipose tissue (i.e. waist circumference (WC), waist to height ratio (WTHR) and radiologically measured abdominal visceral adipose tissue (VAT)), total body adiposity (body mass index (BMI)) and subcutaneous adipose tissue (SAT) (radiologically measured abdominal SAT) and, with cognitive decline and structural brain changes in patients with cardiovascular disease.
Methods: Data were used from the prospective SMART-MR study including 1,304 participants with cardiovascular disease who had baseline and two follow-up assessments approximately 5 and 10 years after baseline, respectively, of cognitive function and brain MRI. Adiposity measures were assessed at baseline only. Linear mixed-effects models were used to estimate the relation between the adiposity measures (all modelled per SD) and changes in z-scores of executive function, memory, total brain volume and white matter hyperintensity volume, adjusted for age, sex, smoking status, packyears, alcohol use and APOE genotype.
Results: Cross-sectionally, higher WTHR was related to lower executive function, memory and total brain volume (-0.135 [-0.198;-0.072], -0.103 [-0.166;-0.040], -0.025 [-0.043;-0.007], respectively), and higher SAT was related to higher executive function (0.074 [0.005;0.143]). In addition, higher WC and WTHR at baseline were related to greater 5-year decline of executive function (-0.030 [-0.057;-0.004], -0.033 [-0.059;-0.006], respectively) and total brain volume (-0.013 [-0.019;-0.006], -0.010 [-0.016;-0.003], respectively). Higher VAT at baseline was related to greater 5-year decline of total brain volume (-0.008 [-0.015;-0.002]) and higher BMI at baseline was related to greater 5-year decline of executive function (-0.032 [-0.059;-0.005]).
Conclusion: Overall adiposity, in particular visceral adiposity, is related to both lower cognitive function and total brain volume, as well as greater decline of these measures. This underscores the importance of adipose tissue distribution rather than overall adiposity in determining brain health.