Fig. 25.

Effect of interaction of smoking history and APOE ε4 genotype on amyloid level and hypometabolism. ADNI participants were grouped on the basis of smoking history and APOE4 status. Smoking status interacted with APOE ε4 carrier status such that APOE4 smokers had higher levels of amyloid and worse hypometabolism than other groups. (A) Florbetapir retention level across groups. Higher values indicate greater Aβ level. Levels above the horizontal line indicate Aβ positivity. Mean ± standard error of the mean. (B) Composite glucose uptake level across groups. Higher values indicate greater glucose metabolism. Mean ± standard error of the mean. Abbreviations: ADNI, Alzheimer’s Disease Neuroimaging Initiative; FDG, [¹⁸F]-fluorodeoxyglucose; SUVR, standardized uptake value ratio. Reproduced with permission from [302].