Attributable Risk of Alzheimer's Dementia Due to Age‐Related Neuropathologies

Abstract

Objective

The degree to which Alzheimer's versus other neuropathologies contribute to the risk of Alzheimer's dementia is unknown. We examined the risk of Alzheimer's dementia attributable to pathologic AD and eight other neuropathologies.

Methods

Participants (n=1,161) came from two clinical‐pathologic studies of aging. Multivariable logistic regression models examined associations of eight neuropathologic indices with Alzheimer's dementia and quantified the percentage of cases attributable to each. Further, because some dementia cases are not driven by common neuropathologies, we re‐estimated the attributable risks after empirically adjusting for such cases.

Results

Of 1,161 persons, 512 (44.1%) had Alzheimer's dementia at the time of death. With the exception of microinfarcts, all neuropathologic indices were independently associated with greater odds of Alzheimer's dementia. 210 (41.0%) Alzheimer's dementia cases were attributable to pathologic AD. Separately, 8.9% were attributable to macroscopic infarcts, 10.8% to Lewy bodies, 5.2% to hippocampal sclerosis, 11.7% to TDP‐43, 8.1% to CAA, 6.0% to atherosclerosis and 5.2% to arteriolosclerosis. A total of 83.3% of cases were attributable to all eight indices combined. However, after further adjustment for cases driven by other factors, a total of 67.5% of cases were attributable to all eight neuropathologic indices combined.

Interpretation

Pathologic AD accounts for a considerable percentage of Alzheimer's dementia cases, but multiple other neuropathologies also contribute. In total, just over two thirds of Alzheimer's dementia cases are attributable to common age‐related neuropathologies, suggesting that other disease and resilience factors are important.

This article is protected by copyright. All rights reserved.

https://ift.tt/2OGU2Bs