Improving cognition by adherence to physical or mental exercise: a moderated mediation analysis

Determinants of Adherence to a "GRADIOR" Computer-Based Cognitive Training Program in People with Mild Cognitive Impairment (MCI) and Mild Dementia

BACKGROUND

Computer-based programs have been implemented from a psychosocial approach for the care of people with dementia (PwD). However, several factors may determine adherence of older PwD to this type of treatment. The aim of this paper was to identify the sociodemographic, cognitive, psychological, and physical-health determinants that helped predict adherence or not to a "GRADIOR" computerized cognitive training (CCT) program in people with mild cognitive impairment (MCI) and mild dementia.

METHOD

This study was part of a randomized clinical trial (RCT) (ISRCTN: 15742788). However, this study will only focus on the experimental group (n = 43) included in the RCT. This group was divided into adherent people (compliance: ≥60% of the sessions and persistence in treatment up to 4 months) and non-adherent. The participants were 60-90 age and diagnosed with MCI and mild dementia. We selected from the evaluation protocol for the RCT, tests that evaluated cognitive aspects (memory and executive functioning), psychological and physical health. The CCT with GRADIOR consisted of attending 2-3 weekly sessions for 4 months with a duration of 30 min Data analysis: Phi and Biserial-point correlations, a multiple logical regression analysis was obtained to find the adherence model and U Mann-Whitney was used.

RESULTS

The adherence model was made up of the Digit Symbol and Arithmetic of Wechsler Adult Intelligence Scale (WAIS-III) and Lexical Verbal Fluency (LVF) -R tests. This model had 90% sensitivity, 50% specificity and 75% precision. The goodness-of-fit p-value of the model was 0.02.

CONCLUSIONS

good executive functioning in attention, working memory (WM), phonological verbal fluency and cognitive flexibility predicted a greater probability that a person would be adherent.

Age differences in the longitudinal associations of leisure-time physical activity and depressive symptoms with cognitive decline in older Taiwanese

Objectives: The associations of physical activity and depressive symptoms with cognitive decline are likely age dependent. The study was therefore aimed to investigate the age differences in the associations of leisure-time physical activity (LTPA) and depressive symptoms with cognitive decline in older Taiwanese.Method: A total of 3545 participants, age ≥50, from 2003 (baseline) and 2007 (end-point) survey datasets were analyzed. Cognitive decline was defined as a decrease of two or more points on the Short Portable Mental Status Questionnaire. The long-term LTPA and depressive symptoms were the change of status between the two time-points. Multivariable logistic regression was conducted to evaluate the longitudinal associations, stratified by age.Results: Significant associations between all levels of long-term LTPA status and cognitive decline were observed for the older group (age ≥70), but not any for the younger group (age 50-69). Significant associations between long-term depressive symptoms status and cognitive decline were also found in all levels for the older group, but only in one level for the younger group. The two odds ratios of cognitive decline between the age groups were further found to be significantly different for those with active LTPA in both time-points (p=.005) and for those with depressive symptoms decreased (p=.014).Conclusion: The findings suggest that there are age differences in the longitudinal associations of LTPA and depressive symptoms with cognitive decline in older Taiwanese. Understanding the pattern of age differences could be helpful in preventing cognitive decline of the elderly.

Effects of Exercise Training Interventions on Executive Function in Older Adults: A Systematic Review and Meta-Analysis

BACKGROUND

Chronic exercise training has been shown be to positively associated with executive function (EF) in older adults. However, whether the exercise training effect on EF is affected by moderators including the specific sub-domain of EF, exercise prescription variables, and sample characteristics remains unknown.

OBJECTIVES

This systematic and meta-analytic review of randomized controlled trials (RCTs) investigated the effects of exercise training on EF in older adults and explored potential moderators underlying the effects of exercise training on EF.

METHODS

In accordance with the PRISMA guidelines, the electronic databases MEDLINE (PubMed) and EMBASE (Scopus) were searched from January 2003 to November 2019. All studies identified for inclusion were peer-reviewed and published in English. To be included, studies had to report findings from older (> 55 years old), cognitively normal adults or adults with mild cognitive impairment (MCI) randomized to an exercise training or a control group. The risk of bias in each study was appraised using the Cochrane risk-of-bias tool. Fixed-effects models were used to compare the effects of exercise training and control conditions on EF assessed at baseline and post-intervention. In addition, subgroup analyses were performed for three moderators (i.e., the specific sub-domain of EF, exercise prescription variables, and sample characteristics).

RESULTS

Thirty-three RCTs were included. Overall, exercise training was associated with a significant small improvement in EF [Q(106) = 260.09, Hedges' g = 0.21; p < 0.01]. The EF sub-domain moderator was not significant [Q(2) = 4.33, p > 0.05], showing that the EF improvement in response to exercise is evident for measures of inhibition, updating, and shifting. Regarding exercise prescription variables, results were significantly moderated by frequency of exercise training [Q(1) = 10.86, p < 0.05], revealing that effect sizes (ESs) were larger for moderate frequency (g = 0.31) as compared to low frequency exercise (g = 0.15). The results also showed type of exercise training moderated the ESs [Q(4) = 26.18, p < 0.05], revealing that ESs were largest for other forms of exercise (g = 0.44), followed by Tai Chi and yoga (g = 0.38), resistance exercise (g = 0.22), aerobic exercise (g = 0.14), and combined exercise (g = 0.10). In addition, The results showed moderated length of training the ESs [Q(2) = 16.64, p < 0.05], revealing that ESs were largest for short length (g = 0.32), followed by mid length (g = 0.26) and long length (g = 0.09). No significant difference in effects was observed as a function of exercise intensity [Q(1) = 2.87 p > 0.05] and session time [Q(2) = 0.21, p > 0.05]. Regarding sample characteristics, the results were significantly moderated by age [Q(2) = 20.64, p < 0.05], with significant benefits for young-old (55-65 years old) (g = 0.30) and mid-old (66-75 years old) (g = 0.25), but no effect on EF for old-old (more than 75 years old). The results were also significantly moderated by physical fitness levels [Q(1) = 10.80, p < 0.05], revealing that ESs were larger for sedentary participants (g = 0.33) as compared to physically fit participants (g = 0.16). In addition, results were also significantly moderated by cognitive status [Q(1) = 11.44, p < 0.05], revealing that ESs were larger for participants with cognitively normal (g = 0.26) as compared to those with mild cognitive impairment (g = 0.08). No significant differences in effects were observed as a function of sex [Q(2) = 5.38, p > 0.05].

CONCLUSIONS

Exercise training showed a small beneficial effect on EF in older adults and the magnitude of the effect was different across some moderators.

Effect of Standing or Walking at a Workstation on Cognitive Function: A Randomized Counterbalanced Trial

OBJECTIVE

In the present study, we examined the effect of working while seated, while standing, or while walking on measures of short-term memory, working memory, selective and sustained attention, and information-processing speed.

BACKGROUND

The advent of computer-based technology has revolutionized the adult workplace, such that average adult full-time employees spend the majority of their working day seated. Prolonged sitting is associated with increasing obesity and chronic health conditions in children and adults. One possible intervention to reduce the negative health impacts of the modern office environment involves modifying the workplace to increase incidental activity and exercise during the workday. Although modifications, such as sit-stand desks, have been shown to improve physiological function, there is mixed information regarding the impact of such office modification on individual cognitive performance and thereby the efficiency of the work environment.

METHOD

In a fully counterbalanced randomized control trial, we assessed the cognitive performance of 45 undergraduate students for up to a 1-hr period in each condition.

RESULTS

The results indicate that there is no significant change in the measures used to assess cognitive performance associated with working while seated, while standing, or while walking at low intensity.

CONCLUSION

These results indicate that cognitive performance is not degraded with short-term use of alternate workstations.

Gender differences in the longitudinal associations of depressive symptoms and leisure-time physical activity with cognitive decline in ≥57year-old Taiwanese

OBJECTIVE

This study investigates the role of gender in the associations of long-term depressive symptoms and leisure-time physical activity (LTPA) with the risk of cognitive decline in elderly Taiwanese.

METHOD

We analyzed 3679 subjects (age ≥57) in the 2003 and 2007 datasets of the Taiwan Longitudinal Survey on Aging, of which data were collected via face-to-face interviews by trained interviewers. We excluded proxy respondents. Multivariable logistic regression analysis examined the associations of long-term depressive symptoms (increased symptoms: CES-D10 scores from <10 to ≥10; decreased symptoms: from ≥10 to <10) and LTPA (frequency, duration, and intensity) with cognitive decline (a decrease of two or more SPMSQ scores).

RESULTS

Women had significant higher percentages of cognitive impairment, compared to men, at the baseline (5.9 vs. 1.5%; χ(2)=51.24, p<0.001) and end-point (10.8 vs. 5.2%;χ(2)=39.5, p<0.001). Men with long-term depressive symptoms had 5.28 greater odds of cognitive decline (OR=5.28, 95%CI=2.84-9.82, p<0.001) and men with increased depressive symptoms had 2.09 greater odds (2.09, 1.24-3.51, p=0.006). No such association was observed in women. Men with consistently high LTPA had 65% (0.35, 0.19-0.65, p=0.001) and women with increased LTPA had 43% (0.57, 0.34-0.93, p=0.024) reduction in odds of developing cognitive decline.

CONCLUSION

We found gender differences in the longitudinal association between depressive symptoms and cognitive decline. Long-term LTPA may loosen the association between long-term depressive symptoms and cognitive decline. These findings are useful in the identification of vulnerable elderly in the Taiwanese population and public health interventions should focus on assisting their cognitive aging.

Executive function and self-regulated exergaming adherence among older adults

The rise in dementia and the evidence of cognitive benefits of exercise for the older adult population together make salient the research into variables affecting cognitive benefit and exercise behavior. One promising avenue for increasing exercise participation has been the introduction of exergaming, a type of exercise that works in combination with virtual reality to enhance both the exercise experience and health outcomes. Past research has revealed that executive function (EF) was related to greater use of self-regulatory strategies, which in turn was related to greater adherence to exercise following an intervention (McAuley et al., 2011). Best et al. (2014) found improvement in EF related to adherence to exercise post- intervention. Anderson-Hanley et al. (2012) found that for older adults aerobic exergaming yielded greater cognitive benefit than traditional exercise alone; however, questions remain as to the possible impact of greater cognitive benefit and other factors on participants’ involvement in exercise following the end of an intervention. The current study presents follow-up data exploring the relationship between EF, self-regulation, and exercise behavior in the post-intervention (naturalistic) period. Herein, it was predicted that higher EF at the start of the naturalistic window, would predict subsequent exercise with an exergame. Contrary to expectations, results suggest that those with poorer EF are likely to exergame more frequently. The results of this study contradict previous literature, but suggest an interesting relationship between EF, self-regulation, and exercise behaviors when exergaming is employed, particularly with older adults with some cognitive decline. We hypothesize that other factors may be at work, perhaps expectation of cognitive benefit might act as a unique motivator.

Improved frontoparietal white matter integrity in overweight children is associated with attendance at an after-school exercise program

Aerobic fitness is associated with white matter integrity (WMI) in adults as measured by diffusion tensor imaging (DTI). This study examined the effect of an 8-month exercise intervention on WMI in children. Participants were 18 sedentary, overweight (BMI≥85th percentile) 8- to 11-year-old children (94% Black), randomly assigned to either an aerobic exercise (n=10) or sedentary attention control group (n=8). Each group was offered an instructor-led after-school program every school day for approximately 8 months. Before and after the program, all subjects participated in DTI scans. Tractography was conducted to isolate the superior longitudinal fasciculus and investigate whether the exercise intervention affected WMI in this region. There was no group by time interaction for WMI in the superior longitudinal fasciculus. There was a group by time by attendance interaction, however, such that higher attendance at the exercise intervention, but not the control intervention, was associated with increased WMI. Heart rate and the total dose of exercise correlated with WMI changes in the exercise group. In the overall sample, increased WMI was associated with improved scores on a measure of attention and improved teacher ratings of executive function. This study indicates that participating in an exercise intervention improves WMI in children as compared to a sedentary after-school program.

Adherence to physical and mental activity interventions: coping plans as a mediator and prior adherence as a moderator

OBJECTIVE

Adherence to behavioural intervention programmes is a necessary condition for beneficial outcomes to be achieved. This study tested whether social cognitive variables and coping plans predict adherence.

DESIGN AND METHODS

 Adherence was examined in a randomized controlled trial with healthy older women (age range: 70-93 years), who were randomized to a physical (N= 86) or a mental (N= 85) activity intervention. Intentions, self-efficacies, coping plans, and objectively measured adherence levels were assessed. A moderated mediation analysis evaluated the power of coping plans to translate intention into behaviour, depending on levels of prior adherence.

RESULTS

 Adherence to the physical activity programme (65%) was significantly lower than adherence to the mental activity programme (84%, p < .001). Intentions (β= .22) weakly predicted adherence in the initiation period of the physical activity programme (6 weeks); pre-action self-efficacy predicted adherence in the initiation period of the mental activity programme (β= .35). In both groups, coping plans predicted mid-period adherence (10 weeks) and long-term adherence (20 weeks), moderated by prior adherence (all ps < .01). Coping plans mediated the relationship between intentions and behaviour only in the exercise condition.

CONCLUSIONS

 Instructing older individuals to generate coping plans facilitated their adherence to physical and mental activity programmes. This effect was larger for participants with lower levels of prior adherence--and may have prevented them from dropping out of the programme.