The Relationship between Physical Exercise and Cognitive Function in Korean Middle Aged and Elderly Adults without Dementia

The benefits of physical exercise on older adults' cognitive function: A cohort study exploring potential mechanisms

BACKGROUND

Despite existing studies showing that physical exercise improves cognitive function in older adults either concurrently or in a delayed manner, studies examining these associations simultaneously are rare. Additionally, the underlying mechanisms in these associations remain incompletely understood.

OBJECTIVE

This study explores the concurrent and delayed (two years later) associations between physical exercise and older adults' cognitive function. This study also investigates the mediating roles of three negative physical, psychological, and social resources: limitations in daily abilities, depressive mood, and isolation from friends, as well as the moderating roles of cognitive reserve on these associations.

DESIGN

A cohort sample of 6646 Chinese older adults (Mean age = 69.28, SD = 7.03) is obtained from the 2016 and 2018 waves of the China Longitudinal Aging Social Survey. Regression analysis was employed to test the concurrent and delayed associations between physical exercise and cognitive function. The bootstrap method was utilized to examine the mediating roles of limitations in daily activities, depression mood, and isolation from friends. Interaction terms were generated to investigate the moderating roles of cognitive reserve.

RESULTS

Physical exercise presents concurrent and delayed positive associations with cognitive function. Limitations in daily activities, depressive mood and isolation from friends mediate the above associations. Moreover, cognitive reserve plays a significant role in buffering the concurrent and delayed negative links between depressive mood, isolation from friends, and cognitive function, with larger negative relationships observed for older adults with lower rather than higher levels of cognitive reserve.

CONCLUSIONS

This study validates the concurrent and delayed benefits of physical exercise on older adults' cognitive function while elucidating the underlying mechanisms. These findings offer practical implications for health policies and intervention programs aimed at enhancing older adults' cognitive function.

Associations between physical activity levels and ATPase inhibitory factor 1 concentrations in older adults

BACKGROUND

Adenosine triphosphatase inhibitory factor 1 (IF1) is a key protein involved in energy metabolism. IF1 has been linked to various age-related diseases, although its relationship with physical activity (PA) remains unclear. Additionally, the apolipoprotein A-I (apoA-I), a PA-modulated lipoprotein, could play a role in this relationship because it shares a binding site with IF1 on the cell-surface ATP synthase. We examined here the associations between chronic PA and plasma IF1 concentrations among older adults, and we investigated whether apoA-I mediated these associations.

METHODS

In the present work, 1096 healthy adults (63.8% females) aged 70 years and over who were involved in the Multidomain Alzheimer Prevention Trial study were included. IF1 plasma concentrations (square root of ng/mL) were measured at the 1-year visit of the Multidomain Alzheimer Prevention Trial, while PA levels (square root of metabolic equivalent task min/week) were assessed using questionnaires administered each year from baseline to the 3-year visit. Multiple linear regressions were performed to investigate the associations between the first-year mean PA levels and IF1 concentrations. Mediation analyses were conducted to examine whether apoA-I mediated these associations. Mixed-effect linear regressions were carried out to investigate whether the 1-year visit IF1 concentrations predicted subsequent changes in PA.

RESULTS

Multiple linear regressions indicated that first-year mean PA levels were positively associated with IF1 concentrations (B = 0.021; SE = 0.010; p = 0.043). Mediation analyses revealed that about 37.7% of this relationship was mediated by apoA-I (Bab = 0.008; SE = 0.004; p = 0.023). Longitudinal investigations demonstrated that higher concentrations of IF1 at the 1-year visit predicted a faster decline in PA levels over the subsequent 2 years (time × IF1: B = -0.148; SE = 0.066; p = 0.025).

CONCLUSION

This study demonstrates that regular PA is associated with plasma IF1 concentrations, and it suggests that apoA-I partly mediates this association. Additionally, this study finds that baseline concentrations of IF1 can predict future changes in PA. However, further research is needed to fully understand the mechanisms underlying these observations.

Effects of Exercise on Urinary AD7c-NTP (Alzheimer-Associated Neuronal Thread Protein) Levels and Cognitive Function Among Active Korean Elderly: A Randomized Controlled Trial

Background

Alzheimer-associated neuronal thread protein (AD7c-NTP) has been demonstrated to have high diagnostic accuracy in differentiating Alzheimer's disease (AD) patients from healthy individuals. However, it is yet unclear whether exercise can lower the level of AD7c-NTP in urine among active Korean elderly.

Objective

To assess the effect of exercise on AD7c-ntp levels in urine and cognitive function among active Korean elderly.

Methods

In total, 40 Korean elderly (≥65 years) were divided into Active Control group (CG, n = 10), Aerobic exercise group (AG, n = 18), and combined Resistance/Aerobic exercise group (RAG, n = 12). A total of 12 weeks of exercise intervention was implemented. At week 0 and 12, cognitive performance (Korean Mini-Mental State Examination, Korean-Color Word Stroop test), grip strength, and body composition (muscle mass and body fat percentage) were measured. Also, a morning urine sample was obtained from each subject. The level of AD7c-NTP was measured using competitive enzyme-linked immunosorbent assay (ELISA).

Results

After 12 weeks of exercise intervention, there was a significant difference of AD7c-NTP levels between RAG and CG (p = 0.026), AG and CG (p = 0.032), respectively. Furthermore, the AD7c-NTP levels in urine showed negative correlation with K-MMSE scores (r = -0.390, p = 0.013) and grip strength (r = -0.376, p = 0.017), among all participants after exercise intervention.

Conclusions

This is the first study to investigate urine biomarker through exercise intervention. In future stuides, participants who have low cognitive function and low activity levels need to be recruited to observe more significant 'Exercise' effect.

Relationship between Cognition, Depression, and Oral health status in Older adults: A longitudinal cross-lagged analysis

BACKGROUND

The world's population is aging increasingly, and older adults' physical and mental health needs to be prioritized. Although several studies have explored the relationship between cognition, depression, and oral health in older adults, the exact nature and direction of this relationship are poorly understood. Moreover, most studies to date have been cross-sectional, with fewer longitudinal studies. The current longitudinal study explored the relationship between cognition, depression, and oral health in older adults.

METHODS

We used data from two waves (2018, 2020) of the Korean Longitudinal Study of Aging, which included 4543 older adults aged 60 years and older. General socio-demographic characteristics were analyzed using descriptive analysis, and study variables were described using t-tests. Generalized Estimating Equations (GEE) and cross-lagged models were used to examine the longitudinal associations between cognition, depression, and oral health.

RESULTS

The GEE results suggested that better cognition and less depression over time were associated with better oral health in older adults. Cross-lagged models further validated the effect of depression on oral health over time.

LIMITATIONS

The directionality of the influence of cognition on oral health could not be determined.

CONCLUSIONS

Although there were several limitations, our study provided novel ideas for verifying the effects of cognition and depression on oral health in older adults.

Is Subjective Age Associated with Physical Fitness in Community-Dwelling Older Adults?

Although subjective age has been associated with a range of health-related outcomes, there has been little systematic study on the relationship between the subjective age and physical fitness in a given population. The purpose of this study was to determine the prospective association between subjective age and physical fitness in community-dwelling older adults. A sample of 276 older people who lived in the community was studied. Subjective age was measured by a face-to-face interview. Grip strength, balancing on one leg with eyes open, the 30 s chair stand test, 4 m habitual walk, and 6 min walk test were measured to reflect physical fitness. Results indicated that the felt younger older adults had a higher level of physical fitness compared to their felt older and felt the same counterparts. Multiple linear regression analysis indicated that all the measured physical fitness items were significantly associated with subjective age in older men. All of the measured physical fitness items except for the 4 m habitual walk were remarkably related to subjective age in older women. The findings suggest that subjective age is closely associated with physical fitness in community-dwelling older adults. Much attention should be paid to the promotion of physical fitness to improve the subjective age of older adults.