In a new study from the University of Melbourne and elsewhere, researchers found individuals who are diagnosed with high blood pressure at ages 35-44 had smaller brain size and were more likely to develop dementia compared to people who had normal blood pressure.
The results raise the possibility that taking steps in young adulthood to control or delay the onset of high blood pressure may reduce the risk of dementia.
In the study, the team analyzed data from participants in the UK Biobank, a large database containing detailed anonymous health information of about half a million volunteer participants in the United Kingdom.
To determine brain changes, they compared magnetic resonance imaging (MRI) measurements of brain volume between two large groups of adults in the database: 11,399 people with high blood pressure diagnosed at different ages (younger than age 35; 35-44 years; and 45-54 years), and 11,399 participants who did not have high blood pressure.
From the MRI scans, the team found in each diagnostic age category (from 35 to 54), the total brain volume was smaller in people diagnosed with high blood pressure, and the brain volume of several regions were also smaller compared to the participants who did not have high blood pressure.
Hypertension diagnosed before age 35 was associated with the largest reductions in brain volume compared with controls.
Analyzing the occurrence of dementia in relation to blood pressure diagnosis, the researchers found:
The risk of dementia from any cause was significantly higher (61%) in people diagnosed with high blood pressure between the ages of 35 and 44 compared to participants who did not have high blood pressure.
The risk of vascular dementia (a common form of dementia resulting from impaired blood flow to parts of the brain, as might happen after one or more small strokes) was 45% higher in the adults diagnosed with hypertension between ages 45-54 and 69% higher in those diagnosed between ages 35-44, compared to participants of the same age without high blood pressure.
Although vascular dementia risk was 80% higher in those diagnosed with high blood pressure before age 35, there were fewer cases of dementia among the younger participants, and the association with high blood pressure was not statistically significant, whereas the risk association was meaningful for individuals ages 45-54 with high blood pressure.
These results provide evidence to suggest an early age at onset of hypertension is associated with the occurrence of dementia and, more importantly, this association is supported by structural changes in brain volume.
The findings raise the possibility that better prevention and control of high blood pressure in early adulthood could help prevent dementia.
If you care about high blood pressure, please read studies about blood pressure recording over 24 hours could predict heart disease best and findings of why sleep is so important for your blood pressure.
For more information about high blood pressure treatment and prevention, please see recent studies about over half of patients skip or stop using high blood pressure drugs and results showing that what you should know about high blood pressure and complications.
The study is published in Hypertension. One author of the study is Mingguang He, M.D., Ph.D.
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