PT  - JOURNAL ARTICLE
AU  - Martikainen, I.K.
AU  - Kemppainen, N.
AU  - Johansson, J.
AU  - Teuho, J.
AU  - Helin, S.
AU  - Liu, Y.
AU  - Helisalmi, S.
AU  - Soininen, H.
AU  - Parkkola, R.
AU  - Ngandu, T.
AU  - Kivipelto, M.
AU  - Rinne, J.O.
TI  - Brain β-Amyloid and Atrophy in Individuals at Increased Risk of Cognitive Decline
AID  - 10.3174/ajnr.A5891
DP  - 2018 Dec 13
TA  - American Journal of Neuroradiology
4099  - http://www.ajnr.org/content/early/2018/12/13/ajnr.A5891.short
4100  - http://www.ajnr.org/content/early/2018/12/13/ajnr.A5891.full
AB  - BACKGROUND AND PURPOSE: The relationship between brain β-amyloid and regional atrophy is still incompletely understood in elderly individuals at risk of dementia. Here, we studied the associations between brain β-amyloid load and regional GM and WM volumes in older adults who were clinically evaluated as being at increased risk of cognitive decline based on cardiovascular risk factors.MATERIALS AND METHODS: Forty subjects (63–81 years of age) were recruited as part of a larger study, the Finnish Geriatric Intervention Study to Prevent Cognitive Impairment and Disability. Neuroimaging consisted of PET using 11C Pittsburgh compound-B and T1-weighted 3D MR imaging for the measurement of brain β-amyloid and GM and WM volumes, respectively. All subjects underwent clinical, genetic, and neuropsychological evaluations for the assessment of cognitive function and the identification of cardiovascular risk factors.RESULTS: Sixteen subjects were visually evaluated as showing cortical β-amyloid (positive for β-amyloid). In the voxel-by-voxel analyses, no significant differences were found in GM and WM volumes between the samples positive and negative for β-amyloid. However, in the sample positive for β-amyloid, increases in 11C Pittsburgh compound-B uptake were associated with reductions in GM volume in the left prefrontal (P = .02) and right temporal lobes (P = .04).CONCLUSIONS: Our results show a significant association between increases in brain β-amyloid and reductions in regional GM volume in individuals at increased risk of cognitive decline. This evidence is consistent with a model in which increases in β-amyloid incite neurodegeneration in memory systems before cognitive impairment manifests.ADAlzheimer diseaseAPOEApolipoprotein EAββ-amyloidPIBPittsburgh compound-BPIB−PIB negativePIB+PIB positive