The online version of this article (https://doi.org/10.1186/s13195-018-0419-2) contains supplementary material, which is available to authorized users.
Interindividual differences in cognitive reserve (CR) are associated with complex and dynamic clinical phenotypes observed in cognitive impairment and dementia. We tested whether (1) CR early in life (E-CR; measured by education and IQ), (2) CR later in life (L-CR; measured by occupation), and (3) CR panel (CR-P) with the additive effects of E-CR and L-CR, act as moderating factors between baseline ventricular size and clinical dementia severity at baseline and across 2 years. We further examined whether this moderation is differentially represented by sex.
We examined a longitudinal model using patients (N = 723; mean age = 70.8 ± 9.4 years; age range = 38–90 years; females = 374) from the Sunnybrook Dementia Study. The patients represented Alzheimer’s disease (n = 439), mild cognitive impairment (n = 77), vascular cognitive impairment (n = 52), Lewy body disease (n = 30), and frontotemporal dementia (n = 125). Statistical analyses included (1) latent growth modeling to determine how clinical dementia severity changes over 2 years (measured by performance on the Dementia Rating Scale), (2) confirmatory factor analysis to establish a baseline E-CR factor, and (3) path analysis to predict dementia severity. Baseline age (continuous) and Apolipoprotein E status (ɛ4−/ɛ4+) were included as covariates.
The association between higher baseline ventricular size and dementia severity was moderated by (1) E-CR and L-CR and (2) CR-P. This association was differentially represented in men and women. Specifically, men in only the low CR-P had higher baseline clinical dementia severity with larger baseline ventricular size. However, women in the low CR-P showed the (1) highest baseline dementia severity and (2) fastest 2-year decline with larger baseline ventricular size.
Clinical dementia severity associated with ventricular size may be (1) selectively moderated by complex and additive CR networks and (2) differentially represented by sex.
ClinicalTrials.gov, NCT01800214. Registered on 27 February 2013.
Additional file 1: Table S1. Frequencies of participants for Hollingshead Index of Social Position (occupation scale) by sex. Table S2. Baseline participant characteristics by clinical diagnoses and sex. Table S3. Baseline participant characteristics by clinical diagnoses and Apolipoprotein E (APOE) status (ɛ4−/ɛ4+). (DOCX 32 kb)13195_2018_419_MOESM1_ESM.docx
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- Clinical dementia severity associated with ventricular size is differentially moderated by cognitive reserve in men and women
Donald T. Stuss
Sandra E. Black
- BioMed Central