Developing high blood pressure at an earlier age can mean more than just heart trouble, it may also make the brain more susceptible to Alzheimer’s disease later in life. Researchers reporting to the American Heart Association find people under 45 years-old with high blood pressure are over 60 percent more prone to developing dementia.
These individuals had smaller brains than peers who did not develop hypertension between the ages of 35 and 44. When it comes to what can cause early onset high blood pressure, poor diet is one of the main factors driving the rising number of cases in this age group. However, no matter how hypertension develops, the results appear to alter brain structure.
“Hypertension is very common in middle-aged people (45-64 years), and early onset high blood pressure is becoming more common,” explains senior author Professor Mingguang He from Melbourne University in a media release.
“Although the association among hypertension, brain health and dementia in later life has been well-established, it was unknown how age at onset of hypertension may affect this association. If this is proven, it would provide some important evidence to suggest earlier intervention to delay the onset of hypertension, which may, in turn, be beneficial in preventing dementia,”
Finding any way possible to prevent dementia
Estimates show the number of dementia cases worldwide will likely triple to 150 million by 2050. With no cure in sight, there is an increasing focus on protective lifestyles – such as healthy dieting and exercise. Health experts already advise at least 150 minutes of moderate physical activity a week – like regular bike rides or brisk walks.
The international team analyzed the medical histories of more than 270,000 people in the UK Biobank – tracking them for up to 14 years. Overall dementia risk was 61 percent higher in those diagnosed with high blood pressure between the ages of 35 and 44.
In particular, vascular dementia cases – a common form caused by impaired blood flow to the brain – soared by 69 percent. Numbers were also 45 percent higher in those with hypertension between 45 and 54 years-old.
The findings were based on 124,053 adults with high blood pressure and the same number matched by age who did not. During the average follow up period of 12 years, 4,626 participants developed some form of dementia.
“Our study’s 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,” says lead author Dr. Xianwen Shang from Guangdong Provincial People’s Hospital in China.
What does high blood pressure do to the brain?
The researchers looked at MRI (magnetic resonance imaging) scans of 11,399 people with high blood pressure who were diagnosed at different ages: younger than 35, 35 to 44, and 45 to 54. The team then compared the results with those from the same number of individuals without hypertension matched for age and multiple health factors.
“Individuals who had hypertension diagnosed at younger ages had smaller brain volumes on these one-time measurements,” Prof. Shang adds. “Future research with brain volumes measured at multiple time points could confirm whether hypertension diagnosed at a younger age is associated with a greater decrease in brain volume over time.”
In each age category, total brain volume was smaller in those diagnosed with high blood pressure as well as several specific regions. Hypertension before the age 35 was associated with the largest reductions in brain volume.
The study, published in the journal Hypertension, suggests better prevention and control of high blood pressure in early adulthood could stop dementia.
“An active screening program to identify individuals with early hypertension and provide earlier, intensive high blood pressure treatment might help reduce the risk of developing dementia in the future,” Prof. He says.
Participants entered the databank between 2006 and 2010 and had MRI scans between 2014 and 2019. The researchers are now planning to examine records to detect if dementia onset was preceded by other medical conditions such as diabetes or stroke.
South West News Service writer Mark Waghorn contributed to this report.
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