A randomized controlled trial of physical activity with individual goal-setting and volunteer mentors to overcome sedentary lifestyle in older adults at risk of cognitive decline: the INDIGO trial protocol

Regular Voluntary Running is Associated with Increased Tumor Vascularization and Immune Cell Infiltration and Decreased Tumor Growth in Mice

Tumors present dysfunctional vasculature that limits blood perfusion and hinders immune cells delivery. We aimed to investigate if regular voluntary running promotes tumor vascular remodelling, improves intratumoral immune cells infiltration and inhibits tumor growth. Tumors were induced in C57BL/6 male mice (n=28) by subcutaneous inoculation in the dorsal region with a suspension of RM1 cells (1.5×10⁵ cells/500 µL PBS) and randomly allocated into two groups: sedentary (n=14) and voluntarily exercised on a wheel (n=14). Seven mice from each group were sacrificed 14 and 28 days after cells' inoculation to evaluate tumor weight, microvessel density, vessels' lumen regularity and the intratumoral quantity of NKG2D receptors, CD4⁺and CD8⁺T cells, by immunohistochemistry. The statistical inference was done through a two-way ANOVA. Exercised mice developed smaller tumors at 14 (0.17±0.1 g vs. 0.48±0.2 g, p<0.05) and 28 (0.92±0.7 g vs. 2.09±1.3 g, p<0.05) days, with higher microvessel density (21.20±3.2 vs. 15.86±4.0 vessels/field, p<0.05), more regular vessels' lumen (1.06±0.2 vs. 1.43±0.2, p<0.05), and higher CD8⁺T cells (464.95±48.0 vs. 364.70±49.4 cells/mm², p<0.01), after 28 days. NKG2D expression was higher in exercised mice at 14 (263.27±25.8 cells/mm², p<0.05) and 28 (295.06±56.2 cells/mm², p<0.001) days. Regular voluntary running modulates tumor vasculature, increases immune cells infiltration and attenuates tumor growth, in mice.

Telephone and Smartphone-Based Interventions for Cognitive and Cardio-Metabolic Health in Middle-Aged and Older Adults: A Systematic Review

PURPOSE

Dementia and cardio-metabolic diseases share many risk factors. Management of these risk factors could contribute to successful aging, including the prevention of cardio-metabolic disease and dementia. The increasing use of smartphones offers an opportunity for remote preventive interventions. We provided a systematic review of telephone and smartphone-based interventions targeting the prevention of cognitive decline, dementia cardio-metabolic diseases or their risk factors among adults aged over 50 years.

PATIENTS AND METHODS

We searched Pubmed and the International Clinical Trials Registry Platform for experimental studies. We used the Cochrane risk-of-bias tool (Version 2) for randomized trials or TREND (Transparent Reporting of Evaluations with Nonrandomized Designs) checklists to assess study quality for completed studies.

RESULTS

We analyzed 21 completed (3 for cognition, 18 for cardio-metabolic outcomes) and 50 ongoing studies (23 for cognition, 27 for cardio-metabolic outcomes). Smartphone interventions were used in 26 studies (3 completed, 23 ongoing). Other interventions involved telephone vocal support and text messaging. Few studies were at low risk of bias. There were heterogeneous cognitive and cardio-metabolic outcomes. The highest quality studies found no significant effects on cognition, and inconsistent results for HbA1c, blood pressure or physical activity. The lower quality-studies found effects on global cognition, working memory, memory and language and inconsistent results for clinical, biological or behavioral cardio-metabolic outcomes.

CONCLUSION AND IMPLICATIONS

Despite the large number of commercially available mobile health applications, the magnitude of the scientific evidence base remains very limited. Based on published studies, the added value of telephone and smartphone tools for the prevention of cardio-metabolic diseases, cognitive decline or dementia is currently uncertain, but, there are several ongoing studies expected to be completed in the coming years.

Factors Influencing Long-Term Physical Activity Maintenance: A Qualitative Evaluation of a Physical Activity Program for Inactive Older Adults at Risk of Cognitive Decline: The INDIGO Follow-Up Study

BACKGROUND

Physical inactivity is a modifiable risk factor for dementia, but there remains a research translation gap in effective physical activity (PA) implementation, particularly in the longer-term. The INDIGO trial investigated the effectiveness of a six-month PA intervention for inactive older adults at risk of cognitive decline with subjective cognitive decline or mild cognitive impairment.

OBJECTIVE

This follow-up study aimed to collect feedback from INDIGO participants about their experience of involvement in the trial, including barriers and enablers to longer-term maintenance of PA.

METHODS

A qualitative study using semi-structured individual interviews was conducted and transcripts analyzed thematically. All INDIGO trial completers were invited, with 29 participating (follow-up period 27-66 months post-baseline).

RESULTS

At long-term follow-up, participants described INDIGO trial participation as beneficial. The theme of "Motivation" (subthemes: structure and accountability, knowledge and expected benefits, preferences and motivation, tools) followed by "Situation" (subthemes: environment and time, social aspects, aging and physical health) appeared to be critical to PA "Action". Most participants had a positive view of goal-setting and peer mentoring/support, but there was some polarization of opinion. Key factors to longer-term "Maintenance" of PA were self-efficacy and perceived benefits, habit formation, and for some participants, enjoyment.

CONCLUSION

PA interventions for older adults at risk of cognitive decline should include behavior change techniques tailored to the individual. Effective techniques should focus on "Motivation" (particularly structure and accountability) and "Situation" factors relevant to individuals with the aim of developing self-efficacy, habit formation, and enjoyment to increase the likelihood of longer-term PA maintenance.

Alzheimer's disease research progress in Australia: The Alzheimer's Association International Conference Satellite Symposium in Sydney

The Alzheimer's Association International Conference held its sixth Satellite Symposium in Sydney, Australia in 2019, highlighting the leadership of Australian researchers in advancing the understanding of and treatment developments for Alzheimer's disease (AD) and other dementias. This leadership includes the Australian Imaging, Biomarker, and Lifestyle Flagship Study of Ageing (AIBL), which has fueled the identification and development of many biomarkers and novel therapeutics. Two multimodal lifestyle intervention studies have been launched in Australia; and Australian researchers have played leadership roles in other global studies in diverse populations. Australian researchers have also played an instrumental role in efforts to understand mechanisms underlying vascular contributions to cognitive impairment and dementia; and through the Women's Healthy Aging Project have elucidated hormonal and other factors that contribute to the increased risk of AD in women. Alleviating the behavioral and psychological symptoms of dementia has also been a strong research and clinical focus in Australia.

A Randomized Controlled Trial on the Effects of a 6-Month Home-Based Physical Activity Program with Individual Goal-Setting and Volunteer Mentors on Physical Activity, Adherence, and Physical Fitness in Inactive Older Adults at Risk of Cognitive Decline: The INDIGO Study

BACKGROUND

Increasing physical activity (PA) in those who have memory concerns requires innovative approaches.

OBJECTIVE

To compare in this randomized controlled trial (RCT) the effects on PA, adherence, and fitness of two approaches to deliver a 6-month home-based PA program in older, inactive individuals at risk of cognitive decline.

METHODS

Individuals (n = 52) aged 60-85 years, inactive with mild cognitive impairment or subjective cognitive decline were recruited from the community and memory clinics. Randomization was to 6 months of 150 min/week moderate intensity PA with either: goal-setting with mentor support; or education and peer contact. A subset of participants (n = 36) continued for a further 6 months. PA, moderate and vigorous PA, and secondary outcomes, fitness, goal performance/satisfaction and self-efficacy were assessed at baseline, 6 and 12 months. Modelling of primary and secondary outcomes was conducted with linear mixed models.

RESULTS

Participants were mean age (±sd) 70.1 (6.4) years. Six-month retention was 88.5%(n = 46). No significant between-group differences were observed for PA or fitness. Post-hoc combined group data showed a significant, moderate-large effect size increase in PA with time. PA increased by a mean 1,662 (943, 2383) steps/day (95%CI) and 1,320 (603, 2037) steps/day at 6 and 12 months (p < 0.001). Median (quartiles Q1-Q3) 6 and 6-12 month combined group adherence was 88.9 (74.4-95.7)%and 84.6 (73.9-95.4)%respectively.

CONCLUSION

In this target group, no differences were detected between groups both intervention strategies were highly effective in increasing PA and fitness.

The Effects of Physical Exercise on Tumor Vasculature: Systematic Review and Meta-analysis

A wealth of evidence supports an association between physical exercise, decreased tumor growth rate, and reduced risk of cancer mortality. In this context, the tumor vascular microenvironment may play a key role in modulating tumor biologic behavior. The present systematic review and meta-analysis aimed to summarize the evidence regarding the effects of physical exercise on tumor vasculature in pre-clinical studies. We performed a computerized research on the PubMed, Scopus, and EBSCO databases to identify pre-clinical studies that evaluated the effect of physical exercise on tumor vascular outcomes. Mean differences were calculated through a random effects model. The present systematic review included 13 studies involving 373 animals. From these, 11 studies evaluated chronic intratumoral vascular adaptations and 2 studies assessed the acute intratumoral vascular adaptations to physical exercise. The chronic intratumoral vascular adaptations resulted in higher tumor microvessel density in 4 studies, increased tumor perfusion in 2 studies, and reduced intratumoral hypoxia in 3 studies. Quantitatively, regular physical exercise induced an increased tumor vascularization of 2.13 [1.07, 3.20] (p<0.0001). The acute intratumoral vascular adaptations included increased vascular conductance and reduced vascular resistance, which improved tumor perfusion and attenuated intratumoral hypoxia. In pre-clinical studies, physical exercise seems to improve tumor vascularization.

An ORBIT Phase 1: Design study of a citywide employer-based walking challenges in a predominantly Mexican American metropolitan area

Most Mexican-Americans do not meet current physical activity recommendations. This paper uses the ORBIT model of obesity intervention development as a framework to outline the process of establishing three employer-based walking challenges in El Paso, Texas, a predominantly Mexican American community. The walking challenges were planned and implemented through the Border Coalition for Fitness and participating partnering organizations. Over 2000 participants and several employers took part in the walking challenges. Results from this ORBIT Phase 1 design intervention suggest that walking challenges are a feasible approach to increase physical activity in Mexican-Americans.

A Randomized Controlled Trial of Adherence to a 24-Month Home-Based Physical Activity Program and the Health Benefits for Older Adults at Risk of Alzheimer's Disease: The AIBL Active-Study

Background:

Previous studies have demonstrated that physical activity (PA) interventions can improve physical and cognitive outcomes in older adults, but most have been relatively short in duration (<1 year) with a few having specifically targeting individuals at risk of developing Alzheimer’s disease.

Objective:

To examine adherence and physical health outcomes in a 24-month home-based PA intervention in older adults at risk of Alzheimer’s disease.

Methods:

Participants 60 years and older with mild cognitive impairment (MCI) or subjective memory complaints (SMC) with at least 1 cerebrovascular risk factor recruited from The Australian Imaging Biomarkers and Lifestyle Flagship Study of Aging (AIBL) were randomized to a PA or control group (n = 106). The control group continued with their usual lifestyle. The PA group received a 24-month home-based program with a target of 150 minutes/week of moderate PA and a behavioral intervention. Retention (participants remaining) and PA adherence (PA group only, percent PA completed to the PA prescribed) were determined at 6, 12, 18, and 24 months. Assessments at baseline, 6, 12, and 24 months included, PA; fitness; body composition and fat distribution. Key outcome measures were PA adherence and PA.

Results:

The 24-month retention rate (97.2%) and the median PA adherence 91.67% (Q1–Q3, 81.96, 100.00) were excellent. In the long-term the intervention group achieved significantly better improvements in PA levels, leg strength, fat mass and fat distribution compared to the control.

Conclusion:

This study demonstrates that in this target group, long-term PA adherence is achievable and has physical health benefits.