title: Does medial temporal lobe thickness mediate the association between risk factor burden and memory performance in middle-aged or older adults with metabolic syndrome?
abstract: Metabolic syndrome (MetS) is a cluster of cardiovascular and metabolic abnormalities that together may increase the risk of developing cognitive decline and dementia; however, the neural substrate is incompletely understood. We investigated cortical thickness in the medial temporal lobe (MTL), hippocampal volume, as well as relationships among metabolic risk factor burden, structure and memory performance. Path-analytic models were tested to explore the relations between MetS risk factor, structure and memory performance. Participants were 65 non-demented, middle-aged and older adults, 34 with and 31 without metabolic syndrome. We analyzed archival T1-weighted magnetic resonance imaging (MRI) acquired at 3T and Total Recall and Delayed Recall scores from the Brief Visuospatial Memory Test Revised (BVMT-R). Middle-aged adults with MetS showed less MTL thickness, particularly in entorhinal cortex; while older adults showed a trend for left hippocampal volume loss. Lower MTL thickness, particularly in entorhinal cortex, was associated with greater metabolic risk factor burden in middle-aged adults. In older adults, hippocampal volume was associated with Total Recall and Delayed Recall, while in middle-age entorhinal cortical thickness mediated the association between metabolic disease burden and episodic memory function. The differential findings in middle-aged and older adults with MetS contribute to an understanding of the relationships between metabolic syndrome, structural changes in the brain and increased risk for cognitive decline.
authors.affiliation: San Diego State University, 5500 Campanile Drive, San Diego, CA, 92115 USA.
authors.forename: Elissa C
authors.initials: EC
authors.lastname: McIntosh
authors.affiliation: San Diego State University, 5500 Campanile Drive, San Diego, CA, 92115 USA.
authors.forename: Aaron
authors.initials: A
authors.lastname: Jacobson
authors.affiliation: University of California, San Diego, 9500 Gilman Drive, La Jolla, CA, 92093 USA.
authors.forename: Nobuko
authors.initials: N
authors.lastname: Kemmotsu
authors.affiliation: San Diego State University, 5500 Campanile Drive, San Diego, CA, 92115 USA.
authors.forename: Ekarin
authors.initials: E
authors.lastname: Pongpipat
authors.affiliation: San Diego State University, 5500 Campanile Drive, San Diego, CA, 92115 USA; SDSU/UCSD Joint Doctoral Program in Clinical Psychology, 6363 Alvarado Ct., San Diego, CA, 92120, USA.
authors.forename: Erin
authors.initials: E
authors.lastname: Green
authors.affiliation: University of California, San Diego, 9500 Gilman Drive, La Jolla, CA, 92093 USA; SDSU/UCSD Joint Doctoral Program in Clinical Psychology, 6363 Alvarado Ct., San Diego, CA, 92120, USA.
authors.forename: Lori
authors.initials: L
authors.lastname: Haase
authors.affiliation: San Diego State University, 5500 Campanile Drive, San Diego, CA, 92115 USA; University of California, San Diego, 9500 Gilman Drive, La Jolla, CA, 92093 USA; SDSU/UCSD Joint Doctoral Program in Clinical Psychology, 6363 Alvarado Ct., San Diego, CA, 92120, USA. Electronic address: cmurphy@mail.sdsu.edu.
authors.forename: Claire
authors.initials: C
authors.lastname: Murphy
mesh_terms: D000328:Adult; D000375:Aging / Q000502:physiology*; D000544:Alzheimer Disease / Q000473:pathology; D003072:Cognition Disorders / Q000209:etiology; D005260:Female; D006624:Hippocampus / Q000473:pathology*; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008297:Male; D008569:Memory Disorders / Q000209:etiology / Q000378:metabolism; D011939:Mental Recall / Q000502:physiology; D024821:Metabolic Syndrome / Q000150:complications / Q000473:pathology*; D008875:Middle Aged; D012307:Risk Factors; D013702:Temporal Lobe / Q000378:metabolism / Q000473:pathology*
keywords: Entorhinal cortical thickness; MRI; Medial temporal lobe; Memory; Metabolic syndrome