Affiliations: [a] Department of Neurology, Xuanwu Hospital of Capital Medical University, Beijing, China
| [b] Institute of Biomedical Engineering, School of Communication and Information Engineering, Shanghai University, Shanghai, China
| [c] School of Biomedical Engineering, Hainan University, Haikou, China
| [d] Center of Alzheimer’s Disease, Beijing Institute for Brain Disorders, Beijing, China
| [e]
National Clinical Research Center for Geriatric Disorders, Beijing, China
Correspondence:
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Correspondence to: Ying Han, Department of Neurology, XuanWu Hospital of Capital Medical University, No.45 Changchun Street, Xicheng District, Beijing 100053, China. Tel.: +86 13621011941; E-mail: hanying@xwh.ccmu.edu.cn. and Jiehui Jiang, Institute of Biomedical Engineering, School of Communication and Information Engineering, Shanghai University, 99 Shangda Road, Shanghai 200444, China. Tel.: +86 021 66135299; E-mail: jiangjiehui@shu.edu.cn.
Abstract: Background:Mounting evidence suggests that sex differences exist in cognitive reserve (CR) for cognitively unimpaired (CU) elderly individuals. Global left frontal connectivity (gLFC connectivity) is a reliable neural substrate of CR. Objective:The purpose of this study was to explore sex differences in gLFC connectivity among CU elderly individuals. Methods:One hundred thirteen normal controls (NCs) (women = 66) and 132 individuals with subjective cognitive decline (SCD) (women = 92) were recruited from the Sino Longitudinal Study on Cognitive Decline (SILCODE) (data 1). Among them, 88 subjects underwent amyloid-β (Aβ) imaging, including 32 Aβ+ and 56 Aβ–subjects. Forty-six subjects underwent another rs-fMRI examination (data 2) to validate the repeatability of the calculation of gLFC connectivity, which was determined through seed-based functional connectivity between the LFC and voxels throughout the whole brain. Independent-sample t-tests were used to evaluate the sex differences in gLFC connectivity across different subgroups (NC versus SCD, Aβ+ versus Aβ–). Partial correlation analysis was used to calculate the correlations between gLFC connectivity and cognitive assessments. Results:Women exhibited lower gLFC connectivity in both the NC (p = 0.001) and SCD (p = 0.020) subgroups than men. Women also exhibited lower gLFC connectivity in both the Aβ–(p = 0.006) and Aβ+ (p = 0.025) groups. However, the significant difference disappeared in the Aβ+ group when considering the covariates of age, education, total intracranial volume, and APOE4-carrying status. In addition, gLFC connectivity values were negatively correlated with Geriatric Depression Scale scores in the SCD group (r = –0.176, p = 0.047). Conclusion:Women showed lower gLFC connectivity among CU elderly individuals.
Keywords: Amyloid deposition, cognitive reserve, global left frontal cortex connectivity, sex differences, subjective cognitive decline
