Traumatic brain injury history is associated with earlier age of onset of Alzheimer disease

Abstract

Objective: This study examined whether a history of traumatic brain injury (TBI) is associated with earlier onset of Alzheimer disease (AD), independent of apolipoprotein ε4 status (Apoe4) and gender. Method: Participants with a clinical diagnosis of AD (n = 7625) were obtained from the National Alzheimer’s Coordinating Center Uniform Data Set, and categorized based on self-reported lifetime TBI with loss of consciousness (LOC) (TBI+ vs. TBI−) and presence of Apoe4. ANCOVAs, controlling for gender, race, and education were used to examine the association between history of TBI, presence of Apoe4, and an interaction of both risk factors on estimated age of AD onset. Results: Estimated AD onset differed by TBI history and Apoe4 independently (p’s