Chronotropic Response and Cognitive Function in a Cohort at Risk for Alzheimer’s Disease

Article type: Research Article

Authors: Law, Lena L.^{a; b; c} | Schultz, Stephanie A.^{a; b; c} | Boots, Elizabeth A.^{a; b; c} | Einerson, Jean A.^e | Dougherty, Ryan J.^d | Oh, Jennifer M.^{a; b; c} | Korcarz, Claudia E.^e | Edwards, Dorothy F.^{b; c; d} | Koscik, Rebecca L.^c | Dowling, N. Maritza^f | Gallagher, Catherine L.^{a; b; g} | Bendlin, Barbara B.^{a; b; c} | Carlsson, Cynthia M.^{a; b} | Asthana, Sanjay^{a; b} | Hermann, Bruce P.^{b; c; g} | Sager, Mark A.^{b; c} | Johnson, Sterling C.^{a; b; c} | Cook, Dane B.^{d; h} | Stein, James H.^e | Okonkwo, Ozioma C.^{a; b; c; *}

Affiliations: [a] Geriatric Research Education and Clinical Center, William S. Middleton Memorial Veterans Hospital, Madison, WI, USA | [b] Wisconsin Alzheimer’s Disease Research Center, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA | [c] Wisconsin Alzheimer’s Institute, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA | [d] Department of Kinesiology, University of Wisconsin School of Education, Madison, WI, USA | [e] Division of Cardiology, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA | [f] Department of Biostatistics & Medical Informatics, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA | [g] Department of Neurology, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA | [h] Research Service, William S. Middleton Memorial Veterans Hospital, Madison, WI, USA

Correspondence: [*] Correspondence to: Ozioma C. Okonkwo, Ph.D., Department of Medicine and Alzheimer’s Disease Research Center, University of Wisconsin School of Medicine and Public Health, Madison, WI 53792, USA. Tel.: +1 608 265 4479; Fax: +1 608 265 3091; E-mail: [email protected].

Abstract: The objective of this study was to examine the association of chronotropic response (CR) and heart rate (HR) recovery— two indices of cardiovascular function within the context of a graded exercise test— with cognitive performance in a cognitively healthy, late-middle-aged cohort at risk for Alzheimer’s disease (AD). Ninety participants (age = 63.52±5.86 years; 65.6% female) from the Wisconsin Registry for Alzheimer’s Prevention participated in this study. They underwent graded exercise testing and a comprehensive neuropsychological assessment that assessed the following four cognitive domains: Immediate Memory, Verbal & Learning Memory, Working Memory, and Speed & Flexibility. Regression analyses, adjusted for age, sex, and education, were used to examine the association between CR, HR recovery, and cognition. We found significant associations between CR and cognitive performance in the domains of Immediate Memory, Verbal Learning & Memory, and Speed & Flexibility. In contrast, HR recovery was not significantly associated with cognitive function. The association between CR and cognition persisted even after controlling for HR recovery. Together, these findings indicatethat, in a cognitively normal, late-middle-aged cohort, CR is a stronger correlate of cognitive performance than HR recovery. Overall, this study reinforces the idea that cardiovascular health plays an important role in cognitive function, specifically in a cohort at risk for AD; and that interventions that promote vascular health may be a viable pathway to preventing or slowing cognitive decline due to AD.

Keywords: Alzheimer disease, cardiopulmonary exercise test, cardiovascular health, cognition, heart rate

DOI: 10.3233/JAD-160642

Journal: Journal of Alzheimer's Disease, vol. 56, no. 1, pp. 351-359, 2017