Relationship between mobility and cognitive impairment in patients with Alzheimer's disease

Abstract

Objective: Alzheimer's disease (AD) is usually accompanied by impairments to mobility, performance of the basic activities of daily life (ADL), and progressive cognitive decline. We analyzed the relationship between cognitive performance and related cognitive subdomains and mobility.

Patients and methods: All AD patients of the recruited individuals were living in nursing homes; they underwent a blood analysis, cognitive examination by using the Mini-Mental State Examination, functional evaluation of independence in the ADLs with Barthel score and Katz index, and mobility assessment with the elderly mobility scale.

Results: The mean sample age was 84 years and majority were women; more than 60% of the participants had severe cognitive impairment. Statistically significant relationships were found between the severity of cognitive impairment and functional capacity (p < 0.01) and their degree of mobility (p < 0.05). Among the different domains, memory impairment was not associated with impaired mobility or ability to perform the ADLs. Women had lower scores in the ADL and mobility assessments (p < 0.05) and an increased ratio of severe cognitive impairment (OR = 3.03 95% CI: [1.30, -7.05]) compared to men. Being overweight or obese and high blood levels of HDL cholesterol were directly (p < 0.05) and inversely (p < 0.01) associated with poor cognitive performance in individuals with mild to moderate cognitive dysfunction, respectively.

Conclusions: This study shows that better functional capacity and mobility are generally, but not exclusively, correlated with better cognitive function, depending on the severity of cognitive impairment. In contrast, lipid profile alterations might play a role in cognitive deficits in individuals with mild to moderate cognitive impairment who are overweight. Further longitudinal studies will be required to explore this possibility.

Keywords: Barthel index; Cognitive impairment; Dementia; Institutionalization; Katz index; Lipids; Mobility.