Early- versus Late-Onset Alzheimer Disease: Long-Term Functional Outcomes, Nursing Home Placement, and Risk Factors for Rate of Progression

Background/Aims: Whether age at onset influences functional deterioration in Alzheimer disease (AD) is unclear. We, therefore, investigated risk factors for progression in activities of daily living (ADL) and nursing home placement (NHP) in cholinesterase inhibitor (ChEI)-treated patients with early-onset AD (EOAD) versus late-onset AD (LOAD). Methods: This 3-year, prospective, observational, multicenter study included 1,017 participants with mild-to-moderate AD; 143 had EOAD (onset <65 years) and 874 LOAD (onset ≥65 years). Possible sociodemographic and clinical factors that could affect functional outcome and NHP were analyzed using mixed-effects models and logistic regression, respectively. Results: Younger individuals exhibited longer illness duration before AD diagnosis, whereas 6-month functional response to ChEI therapy, 3-year changes in ADL capacities, time from diagnosis to NHP, and survival time in nursing homes were similar between the groups. In LOAD, a higher ChEI dose, no antidepressant use, and lower education level were protective factors for slower instrumental ADL (IADL) decline. In EOAD, antihypertensives/cardiac therapy implied faster IADL progression but lower risk of NHP. Conclusion: This study highlights the clinical importance of an earlier diagnosis and treatment initiation and the need for functional evaluations in EOAD. Despite the age differences between EOAD and LOAD, a similar need for nursing homes was observed.