Characterization of Mexican Americans with Mild Cognitive Impairment and Alzheimer's Disease

Article type: Research Article

Authors: O'Bryant, Sid E.^{a; b; *} | Johnson, Leigh^{a; b} | Balldin, Valerie^c | Edwards, Melissa^{a; d} | Barber, Robert^{b; e} | Williams, Benjamin^f | Devous, Michael^g | Cushings, Blair^h | Knebl, Janice^a | Hall, James^{b; i}

Affiliations: [a] Department of Internal Medicine, University of North Texas Health Sciences Center, Fort Worth, TX, USA | [b] Institute for Aging & Alzheimer's Disease Research, University of North Texas Health Sciences Center, Fort Worth, TX, USA | [c] South Texas Veterans Health Care System, San Antonio, TX, USA | [d] Department of Clinical Health Psychology, University of North Texas, Denton, TX, USA | [e] Department of Pharmacology and Neuroscience, University of North Texas Health Science Center, Fort Worth, TX, USA | [f] Department of Neurology and Neurotherapeutics, University of Texas Southwestern Medical Center, Dallas, TX, USA | [g] Department of Radiology, University of Texas Southwestern Medical Center, Dallas, TX, USA | [h] Texas College of Osteopathic Medicine, University of North Texas Health Science Center, Fort Worth, TX, USA | [i] Department of Psychiatry, University of North Texas Health Sciences Center, Fort Worth, TX, USA

Correspondence: [*] Correspondence to: Sid E. O'Bryant, Ph.D., Department of Internal Medicine, University of North Texas, Health Sciences Center, 3500 Camp Bowie Blvd, Fort Worth, TX, 76107, USA. Tel.: +1 817 735 2961; E-mail: Sid.O'Bryant@unthsc.edu.

Abstract: The purpose of the study was to provide characterization of Mexican Americans who meet criteria for Alzheimer's disease (AD) and mild cognitive impairment (MCI). For the study, 1,069 participants ages 40 and above who self-identified as either non-Hispanic white (n = 633) or Mexican American (n = 436) were recruited using a community-based participatory research approach. Global cognition was assessed via the Mini-Mental State Examination (MMSE), dementia severity by the Clinical Dementia Rating Scale, and depression via the Geriatric Depression Scale 30-item version. Age, gender, education, ApoE ε4 allele frequency, and diabetic diagnoses were also analyzed. The findings showed that Mexican Americans (normal controls, MCI, and AD) were younger, less highly educated, performed more poorly on the MMSE, endorsed more symptoms of depression, were more likely to be diagnosed with diabetes, and possessed the ApoE ε4 allele less frequently. Age was the only significant risk factor for cognitive dysfunction (AD/MCI) among Mexican Americans (OR = 1.06, 95% CI = 1.03–1.09). Age (B = 0.07, std = 0.02, p < 0.001) and ApoE ε4 presence (B = 0.9, std = 0.4, p = 0.02) were significantly related to increased disease severity. Given the rapidly growing and aging Mexican American population, there is a substantial need for research into cognitive aging, MCI, and AD among this ethnic group. The current findings hold important implications for both clinic and research settings and point to additional research needs.

Keywords: Alzheimer's disease, cognition, depression, diabetes, Hispanic, Mexican American, mild cognitive impairment

DOI: 10.3233/JAD-2012-121420

Journal: Journal of Alzheimer's Disease, vol. 33, no. 2, pp. 373-379, 2013