High blood pressure in 30s linked to later life dementia risk
Treating high blood pressure in young and middle-aged adults could help prevent later life dementia and Alzheimer’s, a new study suggests.
Research published by UC Davis in JAMA Network Open, a monthly open access medical journal produced by the American Medical Association, reveals that hypertension in your 30s is associated with worse brain health around the age of 75, especially in men.
By comparing brain magnetic resonance imaging (MRI) scans of older adults who either did or didn’t have hypertension between the ages of 30 and 40, the researchers found that the high blood pressure group had significantly lower regional brain volumes and worse white matter integrity, both factors linked with dementia.
Some changes, such as decreased grey matter volume and frontal cortex mass, were more apparent in men than women, which the researchers said could be connected to the protective benefits of oestrogen in females before the onset of the menopause.
Other recent studies have also made the connection between hypertension and brain health, including one published last month in the Euroepean Heart Journal.
This latest research reinforces how vital it is that blood pressure is properly managed to avoid any negative impact in later life.
Kristen M George, an assistant professor in the Department of Public Health Sciences at UC Davis in California and first author of the report, said: “Treatment for dementia is extremely limited, so identifying modifiable risk and protective factors over the life course is key to reducing disease burden.
First author of the report, Kristen M. George. Credit UC Davis Health
“High blood pressure is an incredibly common and treatable risk factor associated with dementia. This study indicates hypertension status in early adulthood is important for brain health decades later.”
High blood pressure is cited by the NHS as a sustained reading of more than 140/90 mmHG or above, Anything less than 130/80 mmHG is considered normal.
An estimated 1.3 billion people are affected by hypertension globally and the condition – regarded as the second biggest risk factor for disease after poor diet – kills around 10 million annually, according to figures from the World Heart Federation.
Left untreated it can not only cause heart failure, coronary artery disease and stroke but increase the risk of chronic kidney disease, peripheral arterial disease and vascular dementia.
The UC Davis study noted that the rate of high blood pressure varies by sex and race, with about 50% of men suffering from hypertension compared to 44% of women. The rate of hypertension is about 56% in the adult Black population, 48% in the white community, and 46% and 39% respectively amongst Asian and Hispanic peoples.
African-Americans aged 35-64 are 50% more likely to have high blood pressure than whites.
The researchers looked at data from 427 participants from the Kaiser Healthy Aging and Diverse Life Experiences (KHANDLE) study and the Study of Healthy Aging in African Americans (STAR) spanning 21 years between 1964 and 1985, which provided them with a diverse group of older Asian, Black, Latino and white adults.
They obtained two blood pressure readings from when the participants were between the ages of 30 and 40. This allowed them to determine if they had been hypertensive, were transitioning to elevated blood pressure or had normal BP in young adulthood.
MRI scans of the participants conducted between 2017 and 2022 allowed them to look for late-life neuroimaging biomarkers of neurodegeneration and white matter integrity.
A significant reduction in cerebral gray matter volume was seen in both men and women with hypertension. But it was stronger in males.
Compared to participants with normal blood pressure, the brain scans of those moving to raised BP or with hypertension, showed lower cerebral gray matter volume, frontal cortex volume and fractional anisotropy (a measure of brain connectivity).
The scores for men with high blood pressure were lower than those for women.
The researchers noted that due to the sample size, they could not examine racial and ethnic disparity and recommended interpreting results regarding sex differences with caution.
They also noted that the MRI data was only available from one time-point late in life which could only determine physical properties, like volumetric differences, not specific evidence of neurodegeneration over time.
But Rachel Whitmer, senior author of the study and a professor in the departments of Public Health Sciences and Neurology and chief of the Division of Epidemiology, as well as the associate director of the UC Davis Alzheimer’s Center, said: “This study truly demonstrates the importance of early life risk factors, and that to age well, you need to take care of yourself throughout life – heart health is brain health.
“We are excited to be able to continue following these participants and to uncover more about what one can do in early life to set yourself up for healthy brain ageing in late life.”
