Optimal Blood Pressure Keeps Our Brains Younger

Nicolas Cherbuin; Erin I Walsh; Marnie Shaw; Eileen Luders; Kaarin J Anstey; Perminder S Sachdev; Walter P Abhayaratna; Christian Gaser

doi:10.3389/fnagi.2021.694982

Optimal Blood Pressure Keeps Our Brains Younger

Front Aging Neurosci. 2021 Oct 5:13:694982. doi: 10.3389/fnagi.2021.694982. eCollection 2021.

Authors

Nicolas Cherbuin¹, Erin I Walsh¹, Marnie Shaw², Eileen Luders^{1

3}, Kaarin J Anstey^{4

5}, Perminder S Sachdev⁶, Walter P Abhayaratna⁷, Christian Gaser^{8

9}

Affiliations

¹ Centre for Research on Ageing, Health and Wellbeing, Australian National University, Canberra, ACT, Australia.
² College of Engineering & Computer Science, Australian National University, Canberra, ACT, Australia.
³ School of Psychology, University of Auckland, Auckland, New Zealand.
⁴ Neuroscience Research Australia, Sydney, NSW, Australia.
⁵ School of Psychiatry, University of New South Wales, Sydney, NSW, Australia.
⁶ Centre for Healthy Brain Ageing (CHeBA), School of Psychiatry, University of New South Wales, Sydney, NSW, Australia.
⁷ ANU Medical School, Australian National University, Canberra, ACT, Australia.
⁸ Department of Neurology, Jena University Hospital, Jena, Germany.
⁹ Department of Psychiatry and Psychotherapy, Jena University Hospital, Jena, Germany.

Abstract

Background: Elevated blood pressure (BP) is a major health risk factor and the leading global cause of premature death. Hypertension is also a risk factor for cognitive decline and dementia. However, when elevated blood pressure starts impacting cerebral health is less clear. We addressed this gap by estimating how a validated measure of brain health relates to changes in BP over a period of 12 years. Methods: Middle-age (44-46 years at baseline, n = 335, 52% female) and older-age (60-64 years, n = 351, 46% female) cognitively intact individuals underwent up to four brain scans. Brain health was assessed using a machine learning approach to produce an estimate of "observed" age (BrainAGE), which can be contrasted with chronological age. Longitudinal associations between blood pressures and BrainAGE were assessed with linear mixed-effects models. Results: A progressive increase in BP was observed over the follow up (MAP = 0.8 mmHg/year, SD = 0.92; SBP = 1.41 mmHg/year, SD = 1.49; DBP = 0.61 mmHg/year, SD = 0.78). In fully adjusted models, every additional 10 mmHg increase in blood pressure (above 90 for mean, 114 for systolic, and 74 for diastolic blood pressure) was associated with a higher BrainAGE by 65.7 days for mean, and 51.1 days for systolic/diastolic blood pressure. These effects occurred across the blood pressure range and were not exclusively driven by hypertension. Conclusion: Increasing blood pressure is associated with poorer brain health. Compared to a person becoming hypertensive, somebody with an ideal BP is predicted to have a brain that appears more than 6 months younger at midlife.

Keywords: MAP—mean arterial pressure; MRI; diastolic; hypertension; machine learning; systolic.