Optimal Blood Pressure Keeps Our Brains Younger

• Main Authors: Nicolas Cherbuin, Erin I. Walsh, Marnie Shaw, Eileen Luders, Kaarin J. Anstey, Perminder S. Sachdev, Walter P. Abhayaratna, Christian Gaser
• Format: Article
• Language: English
• Published: Frontiers Media S.A. 2021-10-01
• Series: Frontiers in Aging Neuroscience
• Subjects: MAP—mean arterial pressure; systolic; diastolic; hypertension; machine learning; MRI
• Online Access: https://www.frontiersin.org/articles/10.3389/fnagi.2021.694982/full

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.