[2026 University Libraries Research Award Winner]
Dementia is a worldwide health epidemic, affecting approximately 50 million individuals in 2020, with this number expected to reach 152 million by 2050 (Alzheimer’s Disease International, 2018). From 1990 to 2019, dementia cases increased by 160.84%, reflecting the rapidly growing burden of this neurodegenerative disease on individuals, families, and healthcare facilities. In response to these rising trends, The Lancet Commission has identified 12 modifiable risk factors (MRF) linked to developing dementia, wherein if all were eliminated, dementia cases would decrease by 40% globally. Of the 12 modifiable risk factors of dementia, nine are directly linked to physical inactivity, implicating it as a key MRF for dementia development in both men and women (Livingston et al., 2020). Sedentary behavior (SB), defined as waking activities involving less than or equal to 1.5 METs while sitting or reclining (SBRN, 2017) has increased in recent years (Yang et al., 2019) and is linked to cognitive decline (Yan et al., 2020). Increasing physical activity may help offset these effects by reducing overall sedentary time. However, some research has shown cognitively stimulating sedentary behavior (CSSB) such as reading, writing, or computer use may also benefit cognitive function (Verghese et al., 2003; Kurita et al., 2019). However, how PA and CSSB interact, particularly in midlife (ages 40-65) when MRF have the highest preventative potential, remains unclear. Additionally, the heightened susceptibility of APOE ε4 carrier status makes examining both behavioral and genetic risk factors together even more important for clarifying whether CSSB has an impact on delaying Alzheimer’s disease (AD) in midlife. Therefore, this study aims to investigate the joint effects of CSSB and PA on cognitive outcomes in midlife adults with genetic risk.
