@article{8c9c171e9b314d2aa62121e266f00c33,
title = "Indicators of amyloid burden in a population-based study of cognitively normal elderly",
abstract = "Objectives: Secondary prevention trials in subjects with preclinical Alzheimer disease may require documentation of brain amyloidosis. The identification of inexpensive and noninvasive screening variables that can identify individuals who have significant amyloid accumulation would reduce screening costs. Methods: A total of 483 cognitively normal (CN) individuals, aged 70-92 years, from the population-based Mayo Clinic Study of Aging, underwent Pittsburgh compound B (PiB)-PET imaging. Logistic regression determined whether age, sex, APOE genotype, family history, or cognitive performance was associated with odds of a PiB retention ratio <1.4 and <1.5. Area under the receiver operating characteristic curve (AUROC) evaluated the discrimination between PiBpositive and -negative subjects. For each characteristic, we determined the number needed to screen in each age group (70-79 and 80-89) to identify 100 participants with PiB <1.4 or <1.5. Results: A total of 211 (44%) individuals had PiB <1.4 and 151 (31%) <1.5. In univariate and multivariate models, discrimination was modest (AUROC{\~ }0.6-0.7). Multivariately, age and APOE best predicted odds of PiB <1.4 and <1.5. Subjective memory complaints were similar to cognitive test performance in predicting PiB <1.5. Indicators of PiB positivity varied with age. Screening APOE ε4 carriers alone reduced the number needed to screen to enroll 100 subjects with PIB <1.5 by 48% in persons aged 70-79 and 33% in those aged 80-89. Conclusions: Age and APOE genotype are useful predictors of the likelihood of significant amyloid accumulation, but discrimination is modest. Nonetheless, these results suggest that inexpensive and noninvasive measures could significantly reduce the number of CN individuals needed to screen to enroll a given number of amyloid-positive subjects.",
author = "Mielke, {Michelle M.} and Wiste, {Heather J.} and Weigand, {Stephen D.} and Knopman, {David S.} and Lowe, {Val J.} and Roberts, {Rosebud O.} and Geda, {Yonas E.} and Swenson-Dravis, {Dana M.} and Boeve, {Bradley F.} and Senjem, {Matthew L.} and Prashanthi Vemuri and Petersen, {Ronald C.} and Jack, {Clifford R.}",
note = "Funding Information: M. Mielke receives research support from the NIH/NIA. H. Wiste and S. Weigand report no disclosures. D. Knopman serves as Deputy Editor for Neurology {\textregistered}; serves on a Data Safety Monitoring Board for Lilly Pharmaceuticals; is an investigator in clinical trials sponsored by Baxter, Elan Pharmaceuticals, and Forest Pharmaceuticals; and receives research support from the NIH. V. Lowe serves on scientific advisory boards for Bayer Schering Pharma and GE Healthcare and receives research support from GE Healthcare, Siemens Molecular Imaging, the NIH (NIA, NCI), the MN Partnership for Biotechnology and Medical Genomics, and the Leukemia & Lymphoma Society. R. Roberts receives research support from the NIH/NIA and from Abbott Research Labs. Y. Geda receives research support from NIH, the Robert Wood Johnson Foundation, and the European Union Regional Development Fund. D. Swenson-Dravis reports no disclosures. B. Boeve receives research support from Cephalon, Inc., the NIH/NIA, the Alzheimer's Association, and the Center for Inherited Disease Research. M. Senjem and P. Vemuri report no disclosures. R. Petersen serves on scientific advisory boards for Pfizer, Inc., Janssen Alzheimer Immunotherapy, Elan Pharmaceuticals, and GE Healthcare; and receives research support from the NIH/NIA. C. Jack serves on scientific advisory boards for Elan/Janssen AI, Johnson & Johnson, Eli Lilly & Company, GE Healthcare, Bristol Meyer Squib, and Eisai Inc.; and receives research support from Baxter International Inc., Allon Therapeutics, Inc., the NIH/NIA, and the Alexander Family Alzheimer's Disease Research Professorship of the Mayo Foundation. Go to Neurology.org for full disclosures.",
year = "2012",
month = oct,
day = "9",
doi = "10.1212/WNL.0b013e31826e2696",
language = "English (US)",
volume = "79",
pages = "1570--1577",
journal = "Neurology",
issn = "0028-3878",
publisher = "Lippincott Williams and Wilkins",
number = "15",
}