GFAP and Alzheimer disease: In the correlation analyses including CU and CI-AD, valerate and its ratios were associated with amyloid and all the neurodegeneration-related biomarkers, more strongly with amyloid and plasma GFAP (0.45<|rho|<0.59; p < 0.007) and less with plasma pTau-181 and NfL (0.35<|rho|<0.42; p < 0.042).