title: Education and occupation provide reserve in both ApoE ε4 carrier and noncarrier patients with probable Alzheimer's disease.
abstract: According to the reserve hypothesis, a high educational/occupational attainment can modulate Alzheimer's disease (AD) clinical expression. The impact of the Apolipoprotein E (ApoE) ε4 allele on the reserve mechanism in AD has not been assessed. Aim of this European multicenter study was to evaluate the metabolic correlates of reserve and ApoE genotype in early probable AD. 51 AD subjects, 27 ε4 carriers, and 24 noncarriers, underwent FDG-PET brain imaging. We used the general linear model as implemented in SPM2 to test for the linear correlation of a reserve index, accounting for both educational and occupational level, with brain glucose metabolism, controlling for demographic variables (age and gender) and for cognitive performance. We found an inverse correlation between a reserve index, accounting for educational/occupational level, and metabolism in the posterior cingulate cortex and precuneus in both ε4 carriers and noncarriers, and no significant difference between the groups. We show that education and occupation act as proxies for reserve in ε4 carriers, compensating for an unfavorable genetic background; we also show that the degree of compensation does not differ significantly by ApoE ε4 status.
authors.affiliation: Nuclear Medicine Unit and Division of Neuroscience, San Raffaele Scientific Institute, via Olgettina 60, 20132 Milan, Italy.
authors.forename: V
authors.initials: V
authors.lastname: Garibotto
authors.forename: B
authors.initials: B
authors.lastname: Borroni
authors.forename: S
authors.initials: S
authors.lastname: Sorbi
authors.forename: S F
authors.initials: SF
authors.lastname: Cappa
authors.forename: A
authors.initials: A
authors.lastname: Padovani
authors.forename: D
authors.initials: D
authors.lastname: Perani
mesh_terms: D000368:Aged; D000544:Alzheimer Disease / Q000000981:diagnostic imaging* / Q000235:genetics*; D053327:Apolipoprotein E4 / Q000235:genetics*; D001921:Brain / Q000000981:diagnostic imaging*; D058245:Cognitive Reserve / Q000502:physiology*; D004522:Educational Status; D005260:Female; D019788:Fluorodeoxyglucose F18; D006579:Heterozygote; D006801:Humans; D008297:Male; D009790:Occupations; D049268:Positron-Emission Tomography; D019275:Radiopharmaceuticals
chemical_list: D053327:Apolipoprotein E4; D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18