Summary: Higher than average blood pressure during midlife is linked to a greater risk of—and more extensive—brain small-vessel damage in later years.
Source: European Society of Cardiology
A large new analysis published in the European Heart Journal finds that blood pressure above typical midlife levels is associated with more extensive brain damage in older age. The damage, detectable on MRI as white matter hyperintensities (WMH), is tied to cognitive decline, stroke, dementia, mobility problems and mood disorders.
Researchers analyzed data from 37,041 UK Biobank participants aged 40–69 at enrollment, combining baseline clinical measurements collected between March 2006 and October 2010 with follow-up MRI scans acquired between August 2014 and October 2019. The study focused on the relationship between blood pressure measurements—both systolic (the top number) and diastolic (the lower number, measured between heartbeats)—and the later presence and volume of WMH on brain MRI.
WMH appear as bright areas on MRI and indicate damage to the brain’s small blood vessels. These lesions become more common with age and higher blood pressure, and they are linked to increased risk of stroke, dementia and declines in physical and cognitive function.
To make fair comparisons between participants, the research team calculated WMH load as the ratio of WMH volume to the brain’s total white matter volume, adjusting for differences in brain size. Analyses were also adjusted for age, sex, smoking, diabetes and both systolic and diastolic blood pressure at different time points.
The strongest associations were seen for diastolic blood pressure measured before age 50: even diastolic readings within commonly accepted “normal” ranges were linked to greater WMH decades later. Current systolic blood pressure also correlated with higher WMH load, but past midlife diastolic pressure showed the most consistent relationship with later small-vessel brain damage.
Overall, any increase in blood pressure above the normal range was associated with higher WMH burden, including increases below standard treatment thresholds (140/90 mmHg). The association was particularly pronounced among people taking antihypertensive medication, suggesting that early rises in blood pressure—even if not meeting treatment criteria—are relevant to long-term brain health.
Quantitatively, the study reported that for every 10 mmHg rise in systolic blood pressure above the normal range, the WMH load increased by a median factor of 1.126. For every 5 mmHg increase in diastolic pressure, the WMH load rose by a median factor of 1.106. In the top decile of participants with the greatest WMH burden, roughly 24% of the load could be attributed to systolic blood pressure exceeding 120 mmHg, while about 7% could be attributed to diastolic pressure above 70 mmHg—reflecting the greater prevalence of elevated systolic pressure in older adults.
Lead investigator Dr Karolina Wartolowska, clinical research fellow at the Centre for Prevention of Stroke and Dementia, University of Oxford, emphasized two main conclusions. First, diastolic blood pressure in the 40s and 50s appears especially important: keeping diastolic pressure within a healthy range in midlife may reduce the risk of white matter damage decades later. Second, even modest increases in blood pressure below conventional treatment thresholds are associated with more WMH, implying that prevention and long-term blood pressure control beginning in midlife could protect brain health.
The study also discusses plausible biological mechanisms. Sustained elevated pressure may directly injure small cerebral vessels, making them leaky and producing WMH. Alternatively, higher diastolic pressure over time could stiffen larger arteries, increasing pulsatile stress transmitted to the brain and reducing perfusion between heartbeats—both pathways that could damage white matter.
Limitations of the research include the availability of MRI data at only a single follow-up time point, preventing direct measurement of WMH progression. The investigators note that further work is needed to map regional differences in white matter vulnerability and to untangle complex interactions among risk factors such as smoking, diabetes, high cholesterol, obesity and kidney disease.
About this neurology research news
Source: European Society of Cardiology
Contact: Press Office – European Society of Cardiology
Image: The image is in the public domain
Original Research: The study will appear in European Heart Journal