Age-Related Changes in Instrumental and Basic Activities of Daily Living Impairment in Older Adults with Very Mild Alzheimer’s Disease

Background/Aims: Age-related changes in impairments in activities of daily living (ADL) in older adults with very mild Alzheimer’s disease (vmAD) have been scarcely explored. We clarified the characteristics of ADL impairment and examined how ADL impairments differed by age in such patients compared with community-dwelling cognitively normal older adults. Methods: The participants were 107 older adults with vmAD (Mini-Mental State Examination [MMSE] score ≥24), all of whom were first-visit outpatients at the Dementia Clinic of the Department of Neuropsychiatry, Kumamoto University Hospital. The controls were 682 community-dwelling older adults who participated in the 3rd Nakayama Study with MMSE score ≥24. We examined the association of instrumental and basic ADL (IADL and BADL, respectively) independence with the odds of vmAD using multiple logistic regression analysis and determined differences in ADL impairment by age using age- and sex-matched analysis. Results: Impairments in handling finances (OR 57.08), managing medication (OR 5.13), and dressing (OR 3.35; BADL) were associated with greater odds of vmAD. Among those aged 65 years and above, there were fewer patients with vmAD than healthy controls who could independently handle finances and medication. Among patients with vmAD, the percentages of those who could independently manage shopping, food preparation, and housekeeping only decreased after age 74. Age-related decreases in independence were observed in few BADL items; these, however, were temporary. Conclusions: Patients with vmAD show significantly decreased IADL independence from early old age.