O2‐03‐05: Prevalence of Clinically Versus Biologically Defined Alzheimer's Spectrum Entities Using the National Institute on Aging – Alzheimer's Association Research Framework
Year: 2019
Type: article
Abstract: A National Institute on Aging and Alzheimer's Association (NIA-AA) workgroup recently published a research framework where Alzheimer's disease is defined by neuropathologic or biomarker evidence of β-amyloid plaques and tau tangles. Our objective was to estimate age- and sex-specific prevalences of three imaging-biomarker-based definitions of the Alzheimer's disease spectrum from the NIA-AA research framework and compared these entities to clinically defined diagnostic entities commonly linked with Alzheimer's disease. The Mayo Clinic Study of Aging (MCSA) is a population-based cohort study of cognitive aging in Olmsted County, Minnesota. MCSA participants (n=4660) and passively ascertained individuals with dementia (n=553) aged 60–89 were included. Subsets underwent amyloid PET (n=1524) or both amyloid and tau PET imaging (n=576). We estimated the age- and sex-specific prevalence of three NIA-AA Alzheimer's disease spectrum biological diagnoses: Alzheimer's continuum (abnormal amyloid regardless of tau status), Alzheimer's pathologic change (abnormal amyloid but normal tau biomarker), and Alzheimer's disease (abnormal amyloid and tau biomarkers). We compared these prevalence figures to the prevalence of three clinically defined diagnostic groups: dementia, mild cognitive impairment or dementia, and clinically defined probable Alzheimer's disease. The prevalence of all diagnostic entities (biological and clinical) increased rapidly with age with the exception of Alzheimer's pathologic change. The prevalence of biological Alzheimer's disease was greater than clinically defined probable Alzheimer's disease for men and women (about 10% vs. 1% at age 70, 30% vs. 10% at age 85). The only notable difference by sex was greater prevalence of the mild cognitive impairment plus dementia clinical category in men than women. Biologically defined Alzheimer's disease is more prevalent than clinically defined probable Alzheimer's disease at any age, and three times more prevalent at age 85 in men and women. This difference is largely but not exclusively driven by asymptomatic individuals with biological Alzheimer's disease. These findings illustrate the magnitude of the opportunity that potentially exists to impact public health by intervening with disease-specific treatments to prevent symptom onset.
Source: Alzheimer s & Dementia
Authors: Clifford R. Jack, Terry M. Therneau, Stephen D. Weigand, Heather J. Wiste, David S. Knopman, Prashanthi Vemuri, Val J. Lowe, Michelle M. Mielke, Rosebud O. Roberts, Mary M. Machulda, Jonathan Graff-Radford, David T. Jones, Christopher G. Schwarz, Jeffrey L. Gunter, Matthew L. Senjem, Walter A. Rocca, Ronald C. Petersen
Institution: Mayo Clinic
Language: English
Subfield: Psychiatry and Mental health
Field: Medicine
Domain: Health Sciences
Open Access status: bronze
OpenAlex ID: W2980633646