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Stronger effect of amyloid load than APOE genotype on cognitive decline in healthy older adults

2012; Lippincott Williams & Wilkins; Volume: 79; Issue: 16 Linguagem: Inglês

10.1212/wnl.0b013e31826e9ae6

1526-632X

Yen Ying Lim, Kathryn A. Ellis, Robert H. Pietrzak, David Ames, David Darby, Karra Harrington, Ralph N. Martins, Colin L. Masters, Christopher C. Rowe, Greg Savage, Cassandra Szoeke, Victor L. Villemagne, Paul Maruff, Alan Rembach, Alex Bahar‐Fuchs, Andrew Milner, Ashley I. Bush, Belinda M. Brown, Bill Wilson, Brett Trounson, Christopher O’Halloran, Darshan Trivedi, Fiona Lamb, Gaël Chételat, Gareth T. Jones, Graeme O’Keefe, James Lui, Jo Robertson, Jürgen Fripp, Kelly K. Pertile, Maree Farrow, Mark Woodward, Miroslava Rimajova, Neil Killeen, Nicola T. Lautenschlager, Noel G. Faux, Olga Yastrubetskaya, Olivier Salvado, Parnesh Raniga, Paul Yates, Pierrick Bourgeat, Qiao‐Xin Li, Rebecca Lachovitski, Rebecca Rumble, Roger Clarnette, Simon M. Laws, Simon McBride, Tania Taddei, Tiffany Cowie, Vanessa Ward, Vincent Doré,

Functional Brain Connectivity Studies

Objective: Although the APOE ϵ 4 allele is associated with more rapid decline in memory in healthy older adults, the significance of elevated cerebral β-amyloid (Aβ) load for longitudinal changes in cognition is unclear. Methods: Healthy and cognitively normal older adults (n = 141; mean age 76 years) underwent PET neuroimaging for cerebral Aβ, APOE genotyping, and cognitive assessment as part of their baseline assessment in the Australian Imaging Biomarkers and Lifestyle study. Cognitive function was reassessed 18 months later. Results: Linear mixed-model analyses adjusted for baseline cognitive function indicated that, relative to individuals with low cerebral Aβ, individuals with high cerebral Aβ showed significantly greater decline in working memory and verbal and visual episodic memory at 18 months. Compared with noncarriers, APOE ϵ 4 carriers showed a greater decline in visual memory at the 18-month assessment. No interaction between APOE ϵ 4 and cerebral Aβ load was observed for any measure of cognitive function. Conclusions: In this prospective study of healthy older adults, high cerebral Aβ load was associated with greater decline in episodic and working memory over 18 months. The APOE ϵ 4 genotype was also associated with a decline in visual memory, although the effect was less than that observed for cerebral Aβ load.