Comparison of Alzheimer's Disease in Native Americans and Whites

Objective: This study compared medical history and findings on initial clinical examination in Native Americans diagnosed with possible or probable Alzheimer's disease (AD) at Native American satellite clinics of the University of Texas (UT) Southwestern Medical Center's Alzheimer's Disease Center with those of Whites diagnosed with probable AD at the UT Southwestern Medical Center's Alzheimer's Disease Clinic. Methods: The information reviewed was contained in the database of the UT Southwestern Alzheimer's Disease Center. Results: In relation to Whites, Native Americans had slightly but significantly greater age at onset of symptoms (71.7 vs. 69.6 years, t = -2.08, p = .04) and equivalent cognitive scores at evaluation (Mini-Mental State Exam score = 17.4 vs. 18.5, t = 0.98, p = .33), despite significantly lower educational level (11.4 vs. 13.4 years, t = 5.63, p < .001). Native Americans were more frequently depressed on examination (22.8% vs. 9.5%, χ² = 12, p = .001) and reported diabetes, hypertension, and heart disease significantly more often than did Whites (p < .01 for all), but their survival time after AD diagnosis was similar to that of Whites despite these comorbidities. Conclusions: With the exception of a greater prevalence of depression and cardiovascular risk factors in Native Americans than in Whites, Native Americans had a course of illness similar to that of Whites.