Marseglia A, et al. - Using nine-year longitudinal data from the Swedish National Study on Aging and Care-Kungsholmen (n = 2746, age ≥60 years) and the magnetic resonance imaging subsample (n = 455), researchers intended to determine if prediabetes and diabetes accelerate cognitive decline and brain aging, and the initial pathological changes linked to microvascular processes. Findings suggested an independent association of prediabetes and diabetes with accelerated cognitive decline vs diabetes-free status. An association was found between diabetes and larger white matter hyperintensities volume. A cross-sectional association was found between prediabetes and smaller total brain tissue volume, especially smaller white matter volume. Among dementia-free older adults, diabetes and prediabetes accelerate cognitive decline and might forecast microvascular lesions. They did not find associations between prediabetes or diabetes and hippocampal volume.