Linear mixed effects models, adjusted for demographics and vascular and AD risk factors, examined the independent and interactive effects of prediabetes and sex on 2–6 year trajectories of FDG-PET measured cerebral metabolic glucose rate (CMRglu), hippocampal/intracranial volume ratio (HV/IV), cerebrospinal fluid phosphorylated tau-181/amyloid-β1−42 ratio (p-tau181/Aβ1−42), cognitive function (executive function, language, and episodic memory) and the development of dementia. This evidence concerns the gene MAPT and prediabetes syndrome.