Higher Fat-Related Body Composition Measurement and Lower Resting-State Inter-Network Functional Connectivity of APOE ε4 Carrier in Mild Cognitive Impairment Patients With Aβ Deposition

Abstract

Objective We aimed to evaluate the impact of interaction between <i>APOE</i> ε4 carrier status and body composition measurements on intra- and inter-regional functional connectivity (FC) in mild cognitive impairment (MCI) patients with Aβ deposition.Methods MCI patients with and without <i>APOE</i> ε4 allele (carrier, n=86; non-carrier, n=95) underwent neuropsychological battery, resting-state functional magnetic resonance imaging scans, positron emission tomography scans with [¹⁸F]flutemetamol, and bioelectrical impedance analysis for measuring body composition. We employed a priori defined regions of interest to investigate the intra- and inter-network FC profiles of default mode network (DMN), central executive network (CEN), and salience network.Results There was a significant interaction of <i>APOE</i> ε4 carrier status with body fat mass index, visceral fat area, and waist-hip circumference ratio for inter-network FC between DMN and CEN, contributing higher fat-related body composition measurements in the <i>APOE</i> ε4 carrier with lower DMN-CEN FC.Conclusion The present results highlight the detrimental effect of <i>APOE</i> ε4 carrier status on the associations between the fat-related body composition measurements and FC in the MCI patients with Aβ accumulation.