Pathologic Alzheimer disease (AD) accounts for a considerable percentage of Alzheimer dementia cases, but multiple other neuropathologies also contribute, according to a recent study of 1,161 participants. In total, just >two-thirds of Alzheimer dementia cases are attributable to common age‐related neuropathologies, suggesting that other disease and resilience factors are important. Multivariable logistic regression models examined associations of 8 neuropathologic indices with Alzheimer dementia and quantified the percentage of cases attributable to each. Researchers found:
- Of total participants, 512 (44.1%) had Alzheimer dementia at the time of death.
- With the exception of microinfarcts, all neuropathologic indices were independently associated with greater odds of Alzheimer dementia.
- 210 (41.0%) Alzheimer 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 cerebral amyloid angiopathy, 6.0% to atherosclerosis, and 5.2% to arteriolosclerosis.
- A total of 83.3% of cases were attributable to all 8 indices combined.
- However, after further adjustment for cases driven by other factors, a total of 67.5% of cases were attributable to all 8 neuropathologic indices combined.
Boyle PA, Yu L, Leurgans SE, Wilson RS, Brookmeyer R, Schneider JA, Bennett DA. Attributable risk of Alzheimer's dementia due to age‐related neuropathologies. [Published online ahead of print November 12, 2018]. Ann Neurol. doi:10.1002/ana.25380.