TY - JOUR
T1 - Functional reserve
T2 - The residual variance in instrumental activities of daily living not explained by brain structure, cognition, and demographics
AU - Kraal, A. Zarina
AU - Massimo, Lauren
AU - Fletcher, Evan
AU - Carrión, Carmen I.
AU - Medina, Luis D.
AU - Mungas, Dan
AU - Gavett, Brandon E.
AU - Farias, Sarah Tomazewski
N1 - Copyright:
This record is sourced from MEDLINE/PubMed, a database of the U.S. National Library of Medicine
PY - 2021/1/1
Y1 - 2021/1/1
N2 - OBJECTIVE: Cognitive reserve is a concept that explains individual differences in resilience to brain pathology and susceptibility to poor late-life cognitive outcomes. We evaluate the analogous concept of "Functional Reserve," defined as the difference between observed functional abilities and those predicted by brain structure, cognitive performance, and demographics. This study aims to validate the construct of functional reserve by testing its utility in predicting clinical outcomes and exploring its predictors. METHOD: Longitudinal data collected annually for up to 7 years from 1,084 older adults (ndementia = 163; nMCI = 333; nCN = 523) were analyzed. Functional reserve was operationalized as the residual variance in the Lawton-Brody Instrumental Activities of Daily Living (IADL) Scale after accounting for demographics (sex/gender, race, ethnicity, education), neuropathology (gray matter, hippocampal, and white matter hyperintensity volumes), and cognition (executive function, verbal episodic memory, semantic memory, and spatial function). Structural equation models estimated (a) functional reserve's associations with 7-year changes in clinical diagnosis and disease severity and (b) predictors of functional reserve. RESULTS: Functional reserve was lower in dementia versus cognitively normal individuals. Higher baseline functional reserve was associated with lower concurrent dementia severity and slower clinical progression and attenuated the association of cognition with concurrent dementia severity. Physical function and apathy were the strongest predictors of functional reserve. CONCLUSIONS: Results provide preliminary validation of functional reserve for explaining individual differences in susceptibility to IADL dysfunction independent of neuropathology, cognition, and demographics. Physical functioning and apathy are promising modifiable intervention targets to enhance functional reserve in the context of brain atrophy and cognitive decline. (PsycInfo Database Record (c) 2021 APA, all rights reserved).
AB - OBJECTIVE: Cognitive reserve is a concept that explains individual differences in resilience to brain pathology and susceptibility to poor late-life cognitive outcomes. We evaluate the analogous concept of "Functional Reserve," defined as the difference between observed functional abilities and those predicted by brain structure, cognitive performance, and demographics. This study aims to validate the construct of functional reserve by testing its utility in predicting clinical outcomes and exploring its predictors. METHOD: Longitudinal data collected annually for up to 7 years from 1,084 older adults (ndementia = 163; nMCI = 333; nCN = 523) were analyzed. Functional reserve was operationalized as the residual variance in the Lawton-Brody Instrumental Activities of Daily Living (IADL) Scale after accounting for demographics (sex/gender, race, ethnicity, education), neuropathology (gray matter, hippocampal, and white matter hyperintensity volumes), and cognition (executive function, verbal episodic memory, semantic memory, and spatial function). Structural equation models estimated (a) functional reserve's associations with 7-year changes in clinical diagnosis and disease severity and (b) predictors of functional reserve. RESULTS: Functional reserve was lower in dementia versus cognitively normal individuals. Higher baseline functional reserve was associated with lower concurrent dementia severity and slower clinical progression and attenuated the association of cognition with concurrent dementia severity. Physical function and apathy were the strongest predictors of functional reserve. CONCLUSIONS: Results provide preliminary validation of functional reserve for explaining individual differences in susceptibility to IADL dysfunction independent of neuropathology, cognition, and demographics. Physical functioning and apathy are promising modifiable intervention targets to enhance functional reserve in the context of brain atrophy and cognitive decline. (PsycInfo Database Record (c) 2021 APA, all rights reserved).
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U2 - 10.1037/neu0000705
DO - 10.1037/neu0000705
M3 - Article
C2 - 33393797
AN - SCOPUS:85099427413
VL - 35
SP - 19
EP - 32
JO - Neuropsychology
JF - Neuropsychology
SN - 0894-4105
IS - 1
ER -