The Influence of the Otago Exercise Program on Executive Function Among People Living With Mild to Moderate Dementia

The Effects of strEngth aNd BaLance Exercise on Executive Function in People Living With Dementia (ENABLED): A Randomized Controlled Trial

The primary aim of this study is to conduct a pilot 6-month assessor-blinded randomized controlled trial to determine if the Otago Exercise Program plus usual care improves executive function in people living with mild to moderate dementia compared to usual care among those living in a nursing home or assisted living facility. The exploratory aims are to determine if the Otago Exercise Program plus usual care improves inflammatory blood biomarkers, kynurenine metabolites, epigenetics, mobility, balance, cognition, mood, fall-related self-efficacy, health-related quality of life, sleep, physical activity, and falls by sex and race compared to usual care alone among people living with mild to moderate dementia.

Dementia is a growing public health problem. Approximately 46.8 million individuals worldwide were living with dementia in 2015, which is estimated to reach 131.5 million by 2050. The global healthcare expenditure of dementia was $604 billion in 2010, which is projected to dramatically increase. Therefore, there is an urgent need to alleviate this growing public health concern.

Executive function is important for maintaining independence in activities of daily living; yet, people living with dementia often have poor executive function. Executive function includes the abilities to: make decisions, reason, problem-solve, initiate and maintain tasks, as well as adapt to changing cognitive conditions. Poor executive function is linked with other important health markers, such as poor physical function, falls, and mortality. It is possible that these poor health outcomes in people living with dementia may, in part, be explained by shared mechanisms including inflammation, autophagy, and apoptosis. Interestingly, these poor health outcomes among people living with dementia seem to depend on sex and race, with females and African Americans exhibiting greater comorbidities; nevertheless, the underlying mechanisms are poorly understood.

Poor executive function is linked with other important health markers, such as poor physical function and falls via reduced judgement and self-regulation. Cognitive and physical frailty are frequently observed together, likely due to common pathophysiological mechanisms. People living with dementia are often frail and prone to multiple tipping point incidents, potentially leading to adverse health outcomes. Cognitive and physical frailty also seems to depend on sex and race, with females and African Americans exhibiting a higher incidence of dementia; nevertheless, the underlying mechanisms are poorly understood. Overall, people living with dementia often have multiple comorbidities and complex medical needs; thus, research targeted at addressing these health disparities should be a frontline priority.

Exercise may be a viable strategy to improve executive function in people living with dementia. Mounting evidence suggests that strength and balance interventions (≥3x/week) are safe and effective at improving cognition and mobility, as well as reducing falls in cognitively intact community-dwelling older adults. Yet, historically, people living with dementia have been systematically excluded from intervention studies due to researchers' ineligibility criteria. Few studies have examined the influence of exercise on executive functioning among people living with dementia, but have shown no effect; it is possible that the small sample sizes may have contributed to these null findings. Therefore, further research is warranted to improve executive function and other health outcomes among people living with mild to moderate dementia.

Inclusion criteria

• Aged 55 years and older
• Reside in a nursing home or assisted living facility
• Have any type of mild to moderate dementia confirmed by medical records and/or a physician
• Can read, write, and speak English with acceptable visual and auditory acuity
• Able to walk 3 meters with or without the assistance of another person
• Have a legally authorized representative who can provide informed consent
• Able to provide assent
• Able to understand and follow instructions
• Have a life expectancy of ≥12 months as estimated by a healthcare provider

Exclusion criteria

• Reside in the community
• Severe dementia (e.g., Montreal Cognitive Assessment ≤6/30) and are not able to follow instructions
• Severe psychiatric condition
• Progressive neurological disease other than dementia (i.e., neurological disease, such as Parkinson's, that is mild and stable is not an exclusion)
• Delirium
• Acute medical condition
• Medical condition precluding exercise (e.g., unstable cardiac disease)
• Recent surgery affecting mobility
• Enrolled in another research study
• Blindness
• Aphasia
• Enrolled in another research study
• Receiving hospice care