Cardiorespiratory Fitness Associates with Cerebral Vessel Pulsatility in a Cohort Enriched with Risk for Alzheimer's Disease

Kaitlin M Maxa; Carson Hoffman; Leonardo A Rivera-Rivera; Alice Motovylyak; Patrick A Turski; Carol K C Mitchell; Yue Ma; Sara E Berman; Catherine L Gallagher; Barbara B Bendlin; Sanjay Asthana; Mark A Sager; Bruce P Hermann; Sterling C Johnson; Dane B Cook; Oliver Wieben; Ozioma C Okonkwo

doi:10.3233/BPL-190096

Cardiorespiratory Fitness Associates with Cerebral Vessel Pulsatility in a Cohort Enriched with Risk for Alzheimer's Disease

Brain Plast. 2020 Oct 1;5(2):175-184. doi: 10.3233/BPL-190096.

Authors

Kaitlin M Maxa^{1

2}, Carson Hoffman^{3

4}, Leonardo A Rivera-Rivera³, Alice Motovylyak¹, Patrick A Turski⁴, Carol K C Mitchell⁵, Yue Ma¹, Sara E Berman^{1

6}, Catherine L Gallagher^{1

2

7}, Barbara B Bendlin^{1

7

8}, Sanjay Asthana^{1

7

8}, Mark A Sager^{1

8}, Bruce P Hermann^{2

7

8}, Sterling C Johnson^{1

7

8}, Dane B Cook^{9

10}, Oliver Wieben³, Ozioma C Okonkwo^{1

7

8}

Affiliations

¹ Wisconsin Alzheimer's Disease Research Center, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA.
² Department of Neurology, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA.
³ Department of Medical Physics, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA.
⁴ Department of Radiology, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA.
⁵ Department of Medicine, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA.
⁶ UW-Madison Medical Scientist and Neuroscience Training Programs, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA.
⁷ Geriatric Research Education and Clinical Center, William S. Middleton Memorial VA Hospital, Madison, WI, USA.
⁸ Wisconsin Alzheimer's Institute, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA.
⁹ Department of Kinesiology, University of Wisconsin School of Education, Madison, WI, USA.
¹⁰ Research Service, William S. Middleton Memorial Veterans Hospital, Madison, WI, USA.

Abstract

Background: There is increasing evidence that vascular disease risk factors contribute to evolution of the dementia syndrome of Alzheimer's disease (AD). One important measure of cerebrovascular health is pulsatility index (PI) which is thought to represent distal vascular resistance, and has previously been reported to be elevated in AD clinical syndrome. Physical inactivity has emerged as an independent risk factor for cardiovascular disease.

Objective: This study aims to examine the relationship between a measure of habitual physical activity, cardiorespiratory fitness (CRF), and PI in the large cerebral vessels.

Methods: Ninety-two cognitively-healthy adults (age = 65.34±5.95, 72% female) enrolled in the Wisconsin Registry for Alzheimer's Prevention participated in this study. Participants underwent 4D flow brain MRI to measure PI in the internal carotid artery (ICA), basilar artery, middle cerebral artery (MCA), and superior sagittal sinus. Participants also completed a self-report physical activity questionnaire. CRF was calculated using a previously-validated equation that incorporates sex, age, body-mass index, resting heart rate, and self-reported physical activity. A series of linear regression models adjusted for age, sex, APOE4 status, and 10-year atherosclerotic cardiovascular disease risk were used to analyze the relationship between CRF and PI.

Results: Inverse associations were found between CRF and mean PI in the inferior ICA (p = .001), superior ICA (p = .035), and basilar artery (p = .040). No other cerebral vessels revealed significant associations between CRF and PI (p≥.228).

Conclusions: Higher CRF was associated with lower PI in several large cerebral vessels. Since increased pulsatility has been associated with poor brain health and reported in persons with AD, this suggests that aerobic fitness might provide protection against cerebrovascular changes related to the progression of AD clinical syndrome.

Keywords: Alzheimer’s disease; Cardiorespiratory fitness; cerebrovasculature; hemodynamics; pulsatility index.

Abstract

Grants and funding