Roberts, Rosebud O.

Objective To investigate the associations between age, vascular health, and Alzheimer disease (AD) imaging biomarkers in an elderly sample. Methods We identified 430 individuals along the cognitive continuum aged >60 years with amyloid positron emission tomography (PET), tau PET, and magnetic resonance imaging (MRI) scans from the population‐based Mayo Clinic Study of Aging. A subset of 329 individuals had fluorodeoxyglucose (FDG) PET. We ascertained presently existing cardiovascular and metabolic conditions (CMC) from health care records and used the summation of presence/absence of hypertension, hyperlipidemia, cardiac arrhythmias, coronary artery disease, congestive heart failure, diabetes mellitus, and stroke as a surrogate for vascular health. We used global amyloid from Pittsburgh compound B PET, entorhinal cortex tau uptake (ERC‐tau) from tau‐PET, and neurodegeneration in AD signature regions from MRI and FDG‐PET as surrogates for AD pathophysiology. We dichotomized participants into CMC = 0 (CMC − ) versus CMC > 0 (CMC + ) and tested for age‐adjusted group differences in AD biomarkers. Using structural equation models (SEMs), we assessed the impact of vascular health on AD biomarker cascade (amyloid leads to tau leads to neurodegeneration) after considering the direct and indirect age, sex, and apolipoprotein E effects. Results CMC + participants had significantly greater neurodegeneration than CMC − participants but did not differ by amyloid or ERC‐tau. The SEMs showed that (1) vascular health had a significant direct and indirect impact on neurodegeneration but not on amyloid; and (2) vascular health, specifically the presence of hyperlipidemia, had a significant direct impact on ERC‐tau. Interpretation Vascular health had quantifiably greater impact on neurodegeneration in AD regions than on amyloid deposition. Longitudinal studies are warranted to clarify the relationship between tau deposition and vascular health. Ann Neurol 2017;82:706–718

Background/objectives Objective, complete estimates of nursing home ( NH ) use across the spectrum of cognitive decline are needed to help predict future care needs and inform economic models constructed to assess interventions to reduce care needs. Design Retrospective longitudinal study. Setting Olmsted County, MN . Participants Mayo Clinic Study of Aging participants assessed as cognitively normal ( CN ), mild cognitive impairment ( MCI ), previously unrecognized dementia, or prevalent dementia (age = 70–89 years; N = 3,545). Measurements Participants were followed in Centers for Medicare and Medicaid Services (CMS) Minimum Data Set (MDS) NH records and in Rochester Epidemiology Project provider‐linked medical records for 1‐year after assessment of cognition for days of observation, NH use (yes/no), NH days, NH days/days of observation, and mortality. Results In the year after cognition was assessed, for persons categorized as CN , MCI , previously unrecognized dementia, and prevalent dementia respectively, the percentages who died were 1.0%, 2.6%, 4.2%, 21%; the percentages with any NH use were 3.8%, 8.7%, 19%, 40%; for persons with any NH use, median NH days were 27, 38, 120, 305, and median percentages of NH days/days of observation were 7.8%, 12%, 33%, 100%. The year after assessment, among persons with prevalent dementia and any NH use, >50% were a NH resident all days of observation. Pairwise comparisons revealed that each increase in cognitive impairment category exhibited significantly higher proportions with any NH use. One‐year mortality was especially high for persons with prevalent dementia and any NH use (30% vs 13% for those with no NH use); 58% of all deaths among persons with prevalent dementia occurred while a NH resident. Conclusions Findings suggest reductions in NH use could result from quality alternatives to NH admission, both among persons with MCI and persons with dementia, together with suitable options for end‐of‐life care among persons with prevalent dementia.