Abstract Background Subjective cognitive decline (SCD) and mild impairment (MCI) may occur as preclinical stages of Alzheimer's disease (AD), ultimately leading to dementia. Glycated hemoglobin A1c (HbA1c) is a diagnostic marker for diabetes mellitus indicates mortality risk. Objectives This university-based, exploratory retrospective study examined the impact HbA1c serum level on 5-year among ...