Body composition, physical activity, and cognitive function in Down syndrome

About This Grant

People with Down syndrome (DS) have approximately a 90% lifetime risk for developing Alzheimer’s disease (AD). Most adults with DS experience AD-associated reductions in cognitive function which result in impairments in capacity to perform activities of daily living. In populations without DS, mid-life obesity and low levels of physical activity have been identified as modifiable risk factors for the development of AD and cognitive decline. The prevalence of obesity and low levels of moderate-to-vigorous physical activity (MVPA) are higher in adults with DS compared with their typically developed peers. However, information regarding the association between obesity, MVPA, and cognitive function in adults with DS is extremely limited. To date, cross-sectional studies in adults with DS have found that high levels of MVPA are associated with better outcomes for several markers of cognitive function, including executive function, episodic memory, and overall dementia symptomology. Results from cross-sectional evaluations of the association between obesity, defined as body mass index (BMI ≥ 30 kg/m2), and cognitive function in persons with DS have been inconsistent. Previous research suggests that other measures of body composition, such as visceral fat and body fat percent fat might have stronger associations with negative health outcomes for adults with DS than BMI; however, no study has investigated the association between body composition and cognitive function in DS. Additionally, while MVPA has demonstrated potential to reduce risk for co-morbidities such as cardiovascular disease, type 2 diabetes, and overall mortality risk even in the presence of obesity in adults with and without intellectual disability, the potential joint association of obesity and MVPA and cognitive function in adults with DS has yet to be investigated. To examine the role of body composition and physical activity on cognitive function in adults with DS, we will recruit ~70 new adult participants with DS who enroll either of our two ongoing NIH projects investigating the development of AD in adults with DS, i.e., The Brain Outcomes with Lifestyle Change in Down Syndrome (BOLD) clinical trial (R33 AG078967) and the Alzheimer’s Biomarker Consortium-Down syndrome (ABC-DS, U19AG068054). These projects recruit participants across the spectrum of obesity and MVPA and include assessments of cognitive function (Down Syndrome Mental Status Exam, modified Cued Recall, Stoops Cats and Dogs) and MVPA (7-day accelerometer) collected using standardized protocols. For this project we will add a baseline assessment of body composition (visceral fat, body fat percent, lean mass) using dual energy x-ray absorptiometry (DXA). The aims of this project are to evaluate: 1) The association between body composition (visceral fat, body fat percent, and lean mass) and cognitive function and, 2) The joint association of MVPA and obesity (visceral fat and body fat percent) on cognitive function. Completion of this project will provide valuable experience that will be useful for achieving my career goals of developing an independent program of research on healthy aging in DS and will provide data to inform the development of interventions for preventing or delaying AD in DS.