Cognitive decline is mediated by gray matter changes during middle age.
The present theoretical framework of Alzheimer's disease proposes that pathophysiological changes occur 10-20 years before the diagnosis of dementia. We addressed the question of how age-related changes in gray matter mediate the cognitive performance during middle age. Eighty-two participants (40-50 years, ±2) were assessed with a comprehensive neuropsychological battery covering a broad spectrum of cognitive domains and components. Mediation effects were studied with hierarchical regression and bootstrapping analysis. Results showed that more vulnerable cognitive components were related to executive functioning and in a lesser degree to processing speed. Age-related differences in gray matter mainly involved the frontal lobes. Moreover, age-related differences in visuoconstructive, visuospatial functions, reaction time, and mental flexibility and executive control were mediated by several gray matter regions. It is important to increase the knowledge of the impact of brain changes on cognitive function during middle age. To define the early stages of the aging process may allow early detection of pathologic changes and therapeutic interventions.
Faculty of Psychology, University of La Laguna, La Laguna, Tenerife, Spain; Department of Neurobiology, Care Sciences and Society, Section of Clinical Geriatrics, Karolinska Institutet, Stockholm, Sweden.
Daniel
D
Ferreira
Faculty of Psychology, University of La Laguna, La Laguna, Tenerife, Spain.
Yaiza
Y
Molina
Faculty of Psychology, University of La Laguna, La Laguna, Tenerife, Spain.
Alejandra
A
Machado
Department of Neurobiology, Care Sciences and Society, Section of Clinical Geriatrics, Karolinska Institutet, Stockholm, Sweden.
Eric
E
Westman
Department of Neurobiology, Care Sciences and Society, Section of Clinical Geriatrics, Karolinska Institutet, Stockholm, Sweden.
Lars-Olof
LO
Wahlund
Faculty of Psychology, University of La Laguna, La Laguna, Tenerife, Spain.
Antonieta
A
Nieto
Faculty of Psychology, University of La Laguna, La Laguna, Tenerife, Spain.
Rut
R
Correia
Departament de Psiquiatria i Psicobiologia Clínica, Universitat de Barcelona, Barcelona, Spain; Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain.
Carme
C
Junqué
Hospital Universitario de Canarias, La Laguna, Tenerife, Spain.
Lucio
L
Díaz-Flores
Faculty of Psychology, University of La Laguna, La Laguna, Tenerife, Spain. Electronic address: jbarroso@ull.edu.es.
José
J
Barroso
D000328:Adult; D000375:Aging / Q000473:pathology* / Q000523:psychology*; D003071:Cognition / Q000502:physiology*; D003072:Cognition Disorders / Q000175:diagnosis / Q000473:pathology*; D005625:Frontal Lobe / Q000473:pathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests
Bootstrapping analyses; Cognitive decline; Early aging; Gray matter changes; Hierarchical regression analyses; Mediation effect; Middle age