Incidence and risk factors for AD/ADRD among American Indian and Alaska Native US Veterans.

INTRODUCTION: Our goal was to determine Alzheimer's disease (AD) and related dementias (ADRD) incidence and risk factors among American Indian and Alaska Native (AI/AN) veterans, an understudied group. METHODS: We identified AI/AN veterans ≥ 55 years receiving Veterans Health Administration care between 2005 and 2010 (n = 31,341) and a propensity score-matched non-Hispanic White (NHW) group for AD/ADRD (using International Classification of Diseases 9th/10th Revision codes from 2011-2023) incidence rate comparison. Age-adjusted incidence was calculated by direct standardization. Among AI/AN veterans, we determined dementia risk factors using Cox models. RESULTS: Among 31,341 AI/AN veterans (mean age 67.8 years), 16.2% developed AD/ADRD over 9.3 years. Age-adjusted incidence was higher among AI/AN than NHW veterans (19.0 vs. 16.2 per 1000 person-years; incidence rate ratio: 1.17). Vascular conditions, traumatic brain injury, post-traumatic stress disorder, and depression were associated with risk of dementia among AI/AN veterans. DISCUSSION: AI/AN veterans experience higher AD/ADRD burden driven by modifiable risk factors, though findings may not generalize to non-veteran AI/AN populations.