Fig. 5.

Interaction effect of GFAP biomarkers and AT stages on [¹⁸F]FDG uptake at the voxel level. Interaction effect of plasma GFAP (A) or CSF GFAP (B) and AT stages on [¹⁸F]FDG uptake in the whole brain. The first (projection) and second (slice) columns show the areas where A-T- and A + T- participants have a significantly different association than A + T + participants between each GFAP biomarker and [¹⁸F]FDG uptake. The third column depicts the specific association between adjusted [¹⁸F]FDG uptake in the cluster marked with an asterisk (*) and each of the GFAP biomarkers by AT stages. Scatter plots of the other clusters can be found in the Supplementary Material. β and p values shown in the plot correspond to the interaction effect between tau-negative (A-T- and A + T-) and tau-positive (A + T +) groups. AT groups were derived from previously published thresholds on CSF Aβ42/40 and p-tau [1]. Statistical threshold for the voxel-wise analysis was set at p < 0.005 uncorrected for multiple comparisons with a cluster size of k > 100 and p < 0.05 uncorrected for multiple comparisons for the cluster analysis. Abbreviations: Aβ, amyloid-β; A-T-, Aβ-negative tau-negative; A + T-, Aβ-positive tau-negative; A + T + , Aβ-positive tau-positive; CSF, cerebrospinal fluid; [¹⁸F]FDG, [¹⁸F]fluorodeoxyglucose; GFAP, glial fibrillary acidic protein; LI, left inferior; LL, left lateral; LM, left medial; p-tau, phosphorylated tau; RI, right inferior; RL, right lateral; RM, right medial