The Independent and Interactive Associations of Bilingualism and Sex on Cognitive Performance in Hispanics/Latinos of the Hispanic Community Health Study/Study of Latinos

Article type: Research Article

Authors: Lamar, Melissa^{a; b; c; d; *} | León, Adeline^d | Romo, Karina^e | Durazo-Arvizu, Ramon A.^{b; f} | Sachdeva, Shruti^{a; b} | Lipton, Richard B.^g | Perreira, Krista M.^h | Gallo, Linda C.ⁱ | Cai, Jianwen^j | Khambaty, Tasneem^k | Carrasco, Jessica^l | Llabre, Maria M.^m | Eyler, Lisa T.^l | Daviglus, Martha L.^{a; b} | González, Hector M.ⁿ

Affiliations: [a] Department of Medicine, University of Illinois at Chicago, Chicago, IL, USA | [b] Institute for Minority Health Research, University of Illinois at Chicago, Chicago, IL, USA | [c] Rush Alzheimer’s Disease Center, Rush University Medical Center, Chicago, IL, USA | [d] Department of Psychiatry and Behavioral Sciences, Rush University Medical Center, Chicago, IL, USA | [e] University of Minnesota Medical School, Minneapolis, MN, USA | [f] Department of Public Health Sciences, Loyola University, Chicago, IL, USA | [g] Department of Neurology, Albert Einstein College of Medicine, New York, NY, USA | [h] Department of Social Medicine, School of Medicine, University of North Carolina at Chapel Hill, NC, USA | [i] Department of Psychology, San Diego State University, San Diego, CA, USA | [j] Department of Biostatistics, Collaborative Studies Coordinating Center, University of North Carolina, Chapel Hill, NC, USA | [k] Department of Psychology, University of Maryland, Baltimore County (UMBC), Baltimore, MD, USA | [l] Department of Psychiatry, University of California, San Diego, La Jolla, CA, USA | [m] Department of Psychology, University of Miami, Coral Gables, FL, USA | [n] Department of Neuroscience, Shiley-Marcos Alzheimer’s Disease Research Center, University of California San Diego, San Diego, CA, USA

Correspondence: [*] Correspondence to: Melissa Lamar, PhD, Associate Professor, Rush Alzheimer’s Disease Center, Rush University Medical Center, 1750 West Harrison Street, Suite 1000, Chicago, IL, 60612, USA. Tel.: +1 312 942 3365; E-mail: [email protected].

Abstract: Sixty percent of Hispanics/Latinos are bilingual which research suggests may confer certain cognitive advantages. Female sex confers cognitive advantages in verbal learning and memory compared to male sex, regardless of race or ethnicity. Understanding the independent and interactive associations of bilingualism and sex with cognition may aid in predicting cognitive aging in Hispanics/Latinos. We examined baseline (2008–2011) data from the Hispanic Community Health Study/Study of Latinos, a multicenter, prospective community-based study. Our analyses included 6,110 males and females ≥45 years old who self-reported birth and parents’ origin outside of the continental US, Spanish as their first language, and were evaluated in Spanish. Bilingualism was assessed along a Likert scale (1 = only Spanish to 4 = English>Spanish) for language proficiency (reading/spoken) and patterns of use (thinking/socializing). Cognitive testing included verbal learning, memory, fluency, and Digit Symbol Substitution (DSS). Linear regression models adjusted for relevant confounders, the complex survey design, and sampling weights. Participants’ self-reported language proficiency was Spanish better than English, while patterns of use suggested more Spanish than English. Higher language proficiency was associated with higher performance on all cognitive indices while higher patterns of use associated with higher fluency and DSS scores (p-values < 0.01). Female sex was associated with higher performance on all cognitive indices (p-values < 0.05). There were no significant interactions with bilingualism (regardless of metric) by sex on cognition. For Hispanics/Latinos residing in the continental US and reporting birth and parents’ origin elsewhere, bilingualism and female sex have independent cognitive benefits that are important to consider when evaluating cognitive performance.

Keywords: Bilingualism, cognition, Hispanics/Latinos, memory, serial learning, sex differences

DOI: 10.3233/JAD-190019

Journal: Journal of Alzheimer's Disease, vol. 71, no. 4, pp. 1271-1283, 2019