Open AccessIn vivo imaging evidence of poor cognitive resilience to Alzheimer's disease pathology in subjects with very low cognitive reserve from a low‐middle income environment
Author(s) -
Busatto Geraldo F.,
Gobbi Porto Fabio Henrique,
Faria Daniele de Paula,
Squarzoni Paula,
Coutinho Artur Martins,
Garcez Alexandre Teles,
Rosa Pedro Gomes Penteado,
Costa Naomi Antunes da,
Carvalho Cleudiana Lima,
Torralbo Leticia,
Almeida Hernandes Jullie Rosana,
Ono Carla Rachel,
Brucki Sonia Maria Dozzi,
Nitrini Ricardo,
Buchpiguel Carlos Alberto,
Souza Duran Fabio Luis,
Forlenza Orestes Vicente
Publication year - 2020
Publication title -
alzheimer's and dementia: diagnosis, assessment and disease monitoring
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.497
H-Index - 37
ISSN - 2352-8729
DOI - 10.1002/dad2.12122
Subject(s) - dementia , cognitive reserve , psychology , cognition , effects of sleep deprivation on cognitive performance , brain size , boston naming test , cognitive decline , pittsburgh compound b , alzheimer's disease , audiology , gerontology , clinical psychology , medicine , magnetic resonance imaging , psychiatry , disease , radiology
Reduced cognitive reserve (CR) due to very low educational (VLE) levels may influence high dementia rates in low‐middle income environments, leading to decreased cognitive resilience (RES) to Alzheimer´s disease (AD) pathology. However, in vivo findings in VLE groups confirming this prediction are lacking. METHODS: Cognitively impaired patients (with clinically defined AD dementia or amnestic mild cognitive impairment) and cognitively unimpaired older adults (n = 126) were recruited for a positron emission tomography (PET) and magnetic resonance imaging (MRI) investigation in Brazil, including 37 VLE individuals (≤5 years of education). A CR score was generated combining educational attainment and vocabulary knowledge. RES indices to AD pathology were calculated using standardized residuals from linear regression models relating current cognitive performance (episodic memory or overall cognition) to amyloid beta (Aβ) burden Pittsburgh compound‐B ([11C]PiB‐PET). RESULTS: Aβ burden was lower in VLE relative to highly‐educated subjects (controlling for age, sex, and Mini‐Mental Status Exam [MMSE] scores) in the overall cognitively impaired sample, and in dementia subjects when the three clinically defined groups were evaluated separately. In bivariate regression analyses for the overall sample, the RES index based on a composite cognitive score was predicted by CR, socioeconomic status, and hippocampal volume (but not white matter hyperintensities or intracranial volume [ICV]); in the multivariate model, only CR retained significance (and similar results were obtained in the Aβ‐positive subsample). In the multivariate model for the overall sample using the RES index based on memory performance, CR, hippocampal volume, and ICV were significant predictors, whereas only CR retained significance in Aβ‐positive subjects. DISCUSSION: Lower CR consistently predicted less resilience to AD pathology in older adults from a low‐middle income environment.