Type 2 Diabetes Mellitus and Cognitive Decline in Two Large Cohorts of Community-Dwelling Older Adults

OBJECTIVES: To relate diabetes mellitus (DM) status and duration to late‐life cognitive impairment and decline in men and women. DESIGN: Prospective cohort. SETTING: Community. PARTICIPANTS: Five thousand nine hundred seven men in the Physicians' Health Study II and 6,326 women in the Women's Health Study (mean age 74.1 and 71.9, respectively, at baseline cognitive assessment); 553 men and 405 women had DM. MEASUREMENTS: Primary outcomes were general cognition (the Telephone Interview for Cognitive Status (TICS) and a global score averaging five tests) and verbal memory. All participants had second assessments approximately 2 years later; women had third assessments an average of 4 years later. RESULTS: In adjusted linear regression models, participants with DM had significantly lower baseline scores for all outcomes, and longer duration of DM was associated with lower scores (P‐trends