Subjective Well-Being and Bilateral Anterior Insula Functional Connectivity After Exercise Intervention in Older Adults With Mild Cognitive Impairment

Abstract

While it is well known that exercise training is associated with improvement in subjective well-being among older adults, it is unclear if individuals with cognitive impairment experience the same effects elicited by exercise on subjective well-being. We further explored whether the bilateral anterior insula network may be an underlying neural mechanism for the exercise training-related improvements in subjective well-being. We investigated the effects of exercise training on subjective well-being in older adults (78.4 ± 7.1 years) with mild cognitive impairment (MCI; n = 14) and a cognitively normal (CN; n = 14) control group. We specifically assessed the relationship between changes in subjective well-being and changes in functional connectivity (FC) with the bilateral anterior insula from before to after exercise training. Cardiorespiratory fitness, subjective well-being, and resting-state fMRI were measured before and after a 12-week moderate-intensity walking intervention. A seed-based correlation analysis was conducted using the bilateral anterior insula as a priori seed regions of interest. The associations between bilateral anterior insula FC with other brain regions and subjective well-being were computed before and after exercise training, respectively, and the statistical difference between the correlations (before vs after exercise training) was evaluated. There was a significant Group (MCI vs CN) × Time (before vs after exercise training) interaction for subjective well-being, such that while those with MCI demonstrated significantly increased subjective well-being after exercise training, no changes in subjective well-being were observed in CN. Participants with MCI also showed an exercise training-related increase in the bilateral anterior insula FC. While there was no significant correlation between subjective well-being and bilateral anterior insula FC before exercise training, a positive association between subjective well-being and bilateral anterior insula FC was found in the MCI group after exercise training. Our findings indicate that 12 weeks of exercise training may enhance subjective well-being in older adults diagnosed with MCI and, further, suggest that increased bilateral anterior insula FC with other cortical regions may reflect neural network plasticity associated with exercise training-related improvements in subjective well-being.

Large-Scale Network Connectivity and Cognitive Function Changes After Exercise Training in Older Adults with Intact Cognition and Mild Cognitive Impairment

“…Another potential mechanism underpinning the current findings is that ET-related improvements in vascular brain function including enhanced blood flow, greater blood volume, better neuro-vascular coupling may have influenced the BOLD response, which in turn would affect measures of FC [ 58 – 60 ]. In support of these hypotheses, our previous work using the same cohort also consistently showed an ET-related increase in FC [ 20 , 22 , 23 , 61 ] and corresponding improvements in cognitive function [ 20 , 23 ]. Of note, the ET-related increase in the between-network FC was observed in all the core networks (i.e., DMN-FPN B , DMN-SAL B , and FPN-SAL B ) in both CN and MCI participants, suggesting broader effects elicited by ET on compensatory responses between major brain networks.…”

Well-being is associated with cortical thickness network topology of human brain

“…Meanwhile, several resting-state fMRI studies also reported the links between (1) emotional well-being and human brain functional measurements [e.g., regional homogeneity (ReHo) and amplitude of low-frequency fluctuations (ALFF)] in the prefrontal cortex [ 28 – 30 ], subjective well-being and the fractional ALFF in the right precentral gyrus [ 31 ], and emotional well-being and resting state functional measurements in the limbic regions including the posterior cingulate cortex [ 32 ], the thalamus, the hippocampus, and the amygdala [ 33 ]; and between (2) social well-being and ALFF in the temporal gyrus, the limbic regions including the anterior cingulate cortex, the insula and the thalamus [ 34 ]. As well as (3) functional connectivity within the limbic network such as the bilateral anterior insula [ 35 ], and within the default mode network which was responsible for the internal thoughts concerning selfness as well as memory construction [ 36 – 39 ] were correlated with well-being [ 32 , 33 , 40 – 44 ]. Taken together, previous studies mostly concentrated on emotional and social well-being but not examined all the three dimensions of well-being, and there were both distinct and common neural mechanisms in emotional and social well-being [ 15 ].…”