Balance and Mobility Performance along the Alzheimer's Disease Spectrum

Background: Balance impairments are common in patients with Alzheimer's disease (AD) dementia. Objective: We sought to determine the stage along the AD spectrum during which balance impairments appear and identify factors associated with a decline in balance function. Methods: Our cross-sectional study included 295 participants; 71 were cognitively normal (CN), 96 reported subjective cognitive decline (SCD), 72 had amnestic mild cognitive impairment (MCI), and 56 had AD dementia. The balance and mobility function was assessed using the Timed Up and Go test (TUG) and the One-Leg Standing Test (OLST). Results: Participants in the MCI and AD dementia groups were older than those in the cognitively normal and SCD groups. TUG and OLST test scores were linearly correlated with Mini-Mental Status Examination-Korean Version score (MMSE-KC). TUG score increased with greater AD spectrum severity (all p < 0.001), whereas OLST score showed a precipitous impairment starting in the SCD group (all p < 0.001), even after adjusting for age, sex, MMSE-KC, Geriatric depression scale, and body mass index. Based on subgroup analyses, in females and apolipoprotein E (APOE) ϵ4 carriers, there was significant balance/mobility impairment in the SCD group when compared to the CN group. Conclusion: Our results suggest that balance/mobility is related to cognitive function and that balance/mobility impairment can be observed beginning in the SCD stage. Furthermore, CN females and APOE ϵ4 carriers had better balance and mobility when compared to females and APOE ϵ4 carriers along the ADD spectrum/with cognitive impairment respectively.