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Mediation of cognitive function improvements by strength gains after resistance training in older adults with mild cognitive impairment: Outcomes of the study of mental and resistance training
Mavros, Yorgi Gates, Nicola Wilson, Guy C. Jain, Nidhi Meiklejohn, Jacinda Brodaty, Henry Wen, Wei Singh, Nalin Baune, Bernhard T. Suo, Chao
Mavros, Yorgi
Gates, Nicola
Wilson, Guy C.
Jain, Nidhi
Meiklejohn, Jacinda
Brodaty, Henry
Wen, Wei
Singh, Nalin
Baune, Bernhard T.
Suo, Chao
Abstract
Objectives: To determine whether improvements in aerobic capacity (VO2peak) and strength after progressive resistance training (PRT) mediate improvements in cognitive function. Design: Randomized, double‐blind, double‐sham, controlled trial. Setting: University research facility. Participants: Community‐dwelling older adults (aged ≥55) with mild cognitive impairment (MCI) (N = 100). Intervention: PRT and cognitive training (CT), 2 to 3 days per week for 6 months. Measurements: Alzheimer's Disease Assessment Scale–cognitive subscale (ADAS‐Cog); global, executive, and memory domains; peak strength (1 repetition maximum); and VO2peak. Results: PRT increased upper (standardized mean difference (SMD) = 0.69, 95% confidence interval = 0.47, 0.91), lower (SMD = 0.94, 95% CI = 0.69–1.20) and whole‐body (SMD = 0.84, 95% CI = 0.62–1.05) strength and percentage change in VO2peak (8.0%, 95% CI = 2.2–13.8) significantly more than sham exercise. Higher strength scores, but not greater VO2peak, were significantly associated with improvements in cognition (P < .05). Greater lower body strength significantly mediated the effect of PRT on ADAS‐Cog improvements (indirect effect: β = −0.64, 95% CI = −1.38 to −0.004; direct effect: β = −0.37, 95% CI = −1.51–0.78) and global domain (indirect effect: β = 0.12, 95% CI = 0.02–0.22; direct effect: β = −0.003, 95% CI = −0.17–0.16) but not for executive domain (indirect effect: β = 0.11, 95% CI = −0.04–0.26; direct effect: β = 0.03, 95% CI = −0.17–0.23). Conclusion: High‐intensity PRT results in significant improvements in cognitive function, muscle strength, and aerobic capacity in older adults with MCI. Strength gains, but not aerobic capacity changes, mediate the cognitive benefits of PRT. Future investigations are warranted to determine the physiological mechanisms linking strength gains and cognitive benefits.
Keywords
exercise, cognition, resistance training, dementia
Date
2017
Type
Journal article
Journal
Journal of the American Geriatrics Society
Book
Volume
65
Issue
5
Page Range
550-559
Article Number
ACU Department
Research Office
School of Nursing, Midwifery and Paramedicine
Faculty of Health Sciences
School of Nursing, Midwifery and Paramedicine
Faculty of Health Sciences
Relation URI
Source URL
Event URL
Open Access Status
License
File Access
Controlled