Effect of Metabolic Syndrome Risk Factors on Processing Speed and Executive Function in Three Racialized Groups

Article type: Research Article

Authors: Bouges, Shenikqua^{a; b; c} | Fischer, Barbara L.^{a; i; *} | Norton, Derek L.^g | Wyman, Mary F.^{a; c; h} | Lambrou, Nickolas^{a; b} | Zuelsdorff, Megan^{c; d; f} | Van Hulle, Carol A.^{b; c} | Ennis, Gilda E.^{b; c} | James, Taryn T.^{b; c} | Johnson, Adrienne L.^{a; e} | Chin, Nathaniel A.^{b; c} | Carlsson, Cynthia M.^{a; b; c; d} | Gleason, Carey E.^{a; b; c}

Affiliations: [a] VA Geriatric Research, Education and Clinical Center (GRECC), William S. Middleton Memorial Veterans Hospital, Madison, WI, USA | [b] Division of Geriatrics and Gerontology, Department of Medicine, University of Wisconsin (UW) School of Medicine & Public Health, Madison, WI, USA | [c] Wisconsin Alzheimer’s Disease Research Center, UW School of Medicine & Public Health, Madison, WI, USA | [d] Wisconsin Alzheimer’s Institute, UW School of Medicine & Public Health, Madison, WI, USA | [e] University of Wisconsin School of Medicine & Public Health, Center for Tobacco Research and Intervention, Madison, WI, USA | [f] University of Wisconsin – Madison School of Nursing, Madison, WI, USA | [g] Department of Biostatistics and Medical Informatics, University of Wisconsin, Madison, WI, USA | [h] University of Wisconsin School of Medicine & Public Health, Department of Psychiatry, Madison, WI, USA | [i] Division of Neurology, Department of Medicine, University of Wisconsin School of Medicine & Public Health, Madison, WI, USA

Correspondence: [*] Correspondence to: Barbara Fischer, PsyD, University Hospital, Department of Neurology, 600 Highland Avenue, Madison, WI 53792, USA. Tel.: +1 6082635430; E-mail: blfischer@neurology.wisc.edu.

Abstract: Background:Metabolic syndrome (MetS) has been associated with increased risk for Alzheimer’s disease and related dementias (ADRD). Understanding the association of MetS risk factors to processing speed and executive function in the pre-clinical stages of ADRD in under-represented groups would offer insight on potential mechanisms through which MetS associates with ADRD risk. Objective:Examine association of MetS features and processing speed and executive function across three racial groups. Methods:Cognitively unimpaired adults from the Wisconsin Alzheimer’s Disease Research Center and the Wisconsin Registry for Alzheimer’s Disease Prevention completed blood-draws and neuropsychological testing. Six cognitive outcomes were assessed in association to MetS risk factors: Trailmaking Tests A and B, Animal Fluency, Digit Symbol, and composite scores for Processing Speed and Executive Function. Linear mixed effect models were used to assess the relationship between MetS risk factor count and longitudinal cognitive performance across three racialized groups. Results:Participant sample sizes varied by outcome analyzed (N = 714–1,088). African American and Native American groups exhibited higher rates of MetS than non-Hispanic Whites. MetS was associated with processing speed and executive function across all racialized groups. Three-way interaction by racialized group was limited to one cognitive outcome: Trailmaking Test A. Conclusion:Metabolic dysfunction incrementally affects cognitive trajectory, with generally similar associations across racial groups. Since racialized groups exhibit higher levels of both MetS and ADRD, MetS may represent a driving factor for increased ADRD risk experience by racialized group and an important and modifiable target through which to reduce risk of ADRD.

Keywords: African Americans, Alzheimer’s disease and related dementias, American Indian, Black, metabolic syndrome, Native American, race, racialized groups

DOI: 10.3233/JAD-220920

Journal: Journal of Alzheimer's Disease, vol. 92, no. 1, pp. 285-294, 2023