Diabetes in Midlife and Cognitive Change Over 20 Years A Cohort Study

Type 2 diabetes is associated with dementia risk, but evidence is limited for possible associations of diabetes and predi-abetes with cognitive decline. Objective: To determine whether diabetes in midlife is associated with 20-year cognitive decline and to characterize long-term cog-nitive decline across clinical categories of hemoglobin A1c (HbA1c) levels. Design: Prospective cohort study. Setting: The community-based ARIC (Atherosclerosis Risk in Com-munities) study. Participants: 13 351 black and white adults aged 48 to 67 years at baseline (1990 to 1992). Measurements: Diabetes was defined by self-reported physician diagnosis or medication use or HbA1c level of 6.5 % or greater. Undiagnosed diabetes, prediabetes, and glucose control in person