Recent findings highlight what may be an early pathogenic role for systemic inflammation as a driver of cognitive decline in the decades leading up to older adulthood. Within the Atherosclerosis Risk in Communities (ARIC) cohort study, inflammatory biomarkers were measured during middle adulthood. Researchers created an inflammation composite score using 4 blood biomarkers measured at visit 1 (fibrinogen, white blood cell count, von Willebrand factor, and factor VIII); they measured C-reactive protein (CRP) at visit 2. Cognition was assessed over 3 visits spanning 20 years using measures of memory, executive function, and language. 12,336 participants (baseline age 56.8 [5.7], 21% black, 56% women) were included. They found:

• After adjusting for demographic variables, vascular risk factors, and comorbidities, each standard deviation (SD) increase in midlife inflammation composite score was associated with an additional 20-year decline of −0.035 SD on the cognitive composite score.
• There was a similar association between each SD increase in midlife CRP level and additional 20-year cognitive decline (−0.038 SD).
• In cognitive domain-specific analyses, elevated midlife inflammatory markers were most consistently associated with declines in memory.