Cognitive reserve and risk of mobility impairment in older adults

Date

2022

Journal Title

Journal ISSN

Volume Title

Publisher

Wiley-Blackwell Publishing Ltd.

Abstract

Background: Cognitive reserve (CR) protects against cognitive decline and dementia but its relation to mobility impairment has not been established. To address this important gap in the literature, we conducted a longitudinal investigation to test the hypothesis that higher baseline CR was associated with a lower risk of developing mobility impairment in older adults. Methods: Participants were dementia-free older adults who received brain magnetic resonance imaging and had gait speed assessments during follow-up. Using the residuals approach, CR was computed as the variance in the Modified Mini-Mental Status Examination total score, that was left after accounting for structural brain integrity, education, and race. Mobility impairment was defined using a validated cutoff score in gait speed of 0.8 m/s. Logistic regression models using general estimating equations were utilized to examine longitudinal associations between baseline CR and the risk of developing mobility impairment across repeated assessments. Results: Of the participants (n = 237; mean age = 82 years; %female = 56%) who were free of mobility impairment at baseline, 103 developed mobility impairment during follow-up (mean = 3.1 years). Higher CR at baseline was associated with a lower risk of developing incident mobility impairment—odds ratio (OR) = 0.819, 0.67–0.98, p = 0.038 (unadjusted); OR = 0.815, 0.67–0.99, p = 0.04 (adjusted for socio-demographic variables and depression); OR = 0.819, 0.68–0.88, p = 0.035 (adjusted for illness history); OR = 0.824, 0.68–0.99, p = 0.045 (adjusted for white matter hyperintensities); OR = 0.795, 0.65–0.95, p = 0.016 (adjusted for falls history). Conclusion: Higher CR at baseline was protective against developing incident mobility impairment during follow-up among community-residing older adults.

Description

Scholarly article

Keywords

brain, cognitive reserve, mobility impairment, older adults

Citation

Holtzer, R., Zhu, X., Rosso, A.L., & Rosano, C. (2022). Cognitive reserve and risk of mobility impairment in older adults. Journal of the American Geriatrics Society, 70(11). http://doi.org/10.1111/jgs.17979 Epub ahead of print