Effect of Resistance Exercise on Physical Frailty and Cognitive Function in Elderly with Cognitive Frailty

Abstract

The physical phenotypes of frailty and cognitive impairment are interrelated, and share several common pathophysiological mechanisms with physical frailty. The concept of cognitive frailty was proposed to stimulate research in this field. The new construct cognitive frailty is defined by the presence of both physical frailty and cognitive impairment (clinical dementia rating score = 0.5) in the absence of dementia. It is characterized by concurrent physical frailty and potentially reversible cognitive impairment. Consequently, the objective of this study was to determine the effect of high-speed resistance exercise training on cognitive function and physical performance in older adults with cognitive frailty. Second, examined the association between amyloid-β accumulation in the brain using a brain imaging biomarker and physical frailty parameters (weight loss, weakness, exhaustion, slowness, and low physical activity) in older adults with mild cognitive impairment (MCI) and cognitive frailty. Our results revealed that high-speed resistance exercise resulted in significant improvement in cognitive function (processing speed and executive function, both p ≤ 0.05), physical function (SPPB, TUG, gait speed, both p ≤ 0.05), and muscle strength (grip strength, knee extension strength, both p ≤ 0.05). However, no significant (p > 0.05) changes in frailty score or frailty prevalence were observed in both intervention and control groups. Second, each of the mean cortical regions of interest and regional SUVRs (frontal cortex, lateral temporal cortex, parietal cortex, precuneus/posterior cingulate cortex (PC/PCC), hippocampus, basal ganglia, and global SUVR) was associated with gait speed, TUG, SPPB, and weakness. The overall conclusions and suggestions are as follows: High-speed resistance exercise training is effective in improving cognitive function and physical performance in older adults with cognitive frailty. Therefore, it is feasible to use high-speed resistance exercise training to effectively reduce the level of frailty and cognitive disability in older adults with cognitive frailty in community and primary care setting. Furthermore, none of the cortical or regional amyloid levels in the brain were associated with each other in the MCI and cognitive frailty groups. Nevertheless, the present study demonstrated the association between brain amyloid-β levels and weakness depending on the SUVR values of all the brain regions. Further, the global SUVR (temporal cortex, parietal cortex, PC/PCC, basal ganglia) was associated with gait parameters. However, the debate is far from closed, and further studies in this field are needed to confirm or refute our findings. Additional research is needed to elucidate the neural mechanisms underlying this association, ideally involving exercise interventions designed to investigate causal relationships.