Modelling Modifiable Predictors of Age-Related Cognitive Decline: Exercise, Aortic Stiffness, and the Importance of Physical Fitness

Abstract

Background: Previous modelling found that fitness and aortic stiffness both independently predicted spatial working memory (SWM) performance in older people. There is also evidence that greater engagement in moderate intensity exercise contributes to better cognitive performance, potentially working through improving fitness and aortic stiffness. Objective: To investigate the effect of exercise on the previously established relationships between fitness, aortic stiffness, and SWM, and whether these associations differ between older adults of higher and lower fitness. Methods: One hundred and two residents of independent living facilities, aged 60-90 (M = 77.5, SD = 6.9) participated in the study. Measures included computerized cognitive assessment, the Six-Minute Walk fitness test, the CHAMPS physical activity questionnaire, and aortic pulse wave analysis. Multiple structural equation models were used to test hypotheses. Results: Overall, exercise levels had a small additional effect in predicting SWM, working exclusively through fitness, although this was only true for those of lower than average fitness. Additionally, it was found that while fitness was the most important factor in predicting SWM in those of lower fitness, aortic stiffness was the strongest predictor in those of higher fitness. Conclusion: Fitness and aortic stiffness are strong predictors of cognition in older people, and greater engagement in exercise predicted better cognition in those who were of lower fitness. Fitter older people may benefit more from interventions which target aortic stiffness in order to preserve cognitive performance as they age, while those who are less fit may benefit most from improving fitness first, including through increased physical activity.

Association of estimated pulse wave velocity with cognitive function in a multiethnic diverse population: The Northern Manhattan Study

“…This finding does not allow us to speculate on the association between arterial stiffness and physical activity. Better engagement in moderate aerobic exercises has been shown to influence cognitive performance related to arterial stiffness 17 . Future studies are needed to examine this relationship among diverse aging populations.…”

“…Better engagement in moderate aerobic exercises has been shown to influence cognitive performance related to arterial stiffness. 17 Future studies are needed to examine this relationship among diverse aging populations.…”

“… 2 , 3 Recent studies reported an association between increased stiffness and cognitive impairment. 4 , 5 , 6 However, this effect is complex and known to be altered by advanced age, 7 sex at birth, 8 , 9 and cardiovascular risk factors such as hypertension, 10 , 11 atherosclerosis, 12 , 13 , 14 smoking, 15 obesity, 16 low physical activity, 17 and genetic predisposition. 18 , 19 With advancing age, older adults are prone to episodes of systolic hypotension, 20 which, in conjunction with increasing arterial stiffness, have been linked to severe cognitive impairment.…”

Inflammation, Nitro-Oxidative Stress, Impaired Autophagy, and Insulin Resistance as a Mechanistic Convergence Between Arterial Stiffness and Alzheimer’s Disease

“…Furthermore, physical excercise has been reported as a strong predictor of both arterial stiffness and cognition in the elderly. In general, a greater exercise engagement predicted better cognition in those with lower fitness, while arterial stiffness measurements were on their turn indicative of an individual’s physical fitness and cognitive status ( Asamoah et al, 2013 ; Nascimento et al, 2019 ; Pereira et al, 2019 ; Kennedy et al, 2020 ; Mason et al, 2020 ). Additionally, genetic predisposition linked to the APOE4 gene was recently proposed to act synergistically with arterial stiffness to predict cognitive impairment in non-demented elderly ( Rodrigue et al, 2013 ; Cambronero et al, 2018 ; Rivera-Rivera et al, 2020 ; Smirnov et al, 2020 ; Figure 1 ).…”