A recent study conducted by UC Davis reveals that individuals who suffer from high blood pressure during their 30s are more likely to experience poorer brain health by the age of 75, particularly in men.
The study, published in JAMA Network Open, analyzed magnetic resonance imaging (MRI) brain scans of older adults who had high blood pressure in their 30s to 40s and compared them to those who had normal blood pressure.
According to the study, individuals with a history of high blood pressure during their 30s to 40s exhibited lower regional brain volumes and poorer white matter integrity, both of which are linked to a higher risk of dementia.
Moreover, the research discovered that specific regions of the brain, such as the gray matter and frontal cortex, were more negatively impacted in men compared to women. The researchers suggest that these sex differences may be attributed to the protective effects of estrogen before menopause.
Kristen M. George, an assistant professor in the Department of Public Health Sciences and the first author of the study, emphasized the significance of identifying modifiable risk and protective factors throughout one’s life to reduce the disease burden of dementia. Given the limited treatment options available for this condition, this approach is considered crucial.
“High blood pressure,” according to the first author, “is an incredibly common and treatable risk factor associated with dementia.”
The findings of the study show “hypertension status in early adulthood is important for brain health decades later.”
High blood pressure, medically referred to as hypertension, refers to a condition where the pressure of blood against the arterial walls is elevated beyond normal levels. A blood pressure reading of less than 130/80 mmHg is considered normal. According to the Centers for Disease Control and Prevention (CDC), nearly half of all adults in the United States, or approximately 47%, have hypertension.
The prevalence of high blood pressure differs based on sex and race. Men are more likely to develop hypertension, with 50% of them having high blood pressure compared to 44% of women. Among different races, hypertension rates are highest in African American adults at 56%, followed by white adults at 48%, Asian adults at 46%, and Hispanic adults at 39%. Additionally, African Americans between the ages of 35 to 64 years are 50% more prone to develop high blood pressure than their white counterparts.
In order to gather information on a diverse group of older adults, the researchers examined data from two studies, the Kaiser Healthy Aging and Diverse Life Experiences (KHANDLE) study and the Study of Healthy Aging in African Americans (STAR), which involved 427 participants. This data covered the participants’ health records from 1964 to 1985 and included individuals of Asian, Black, Latino, and white descent.
By analyzing blood pressure readings obtained from the participants when they were in their 30s to 40s, the researchers were able to classify them as having normal blood pressure, transitioning to hypertension, or already hypertensive during young adulthood.
Between 2017 and 2022, the participants underwent MRI scans, enabling the researchers to search for late-life neuroimaging biomarkers of neurodegeneration and white matter integrity.
The analysis revealed a considerable decrease in cerebral gray matter volume in both men and women with hypertension. However, the effect was more pronounced in men.
The brain scans of individuals who were transitioning to high blood pressure or already had high blood pressure exhibited lower cerebral gray matter volume, frontal cortex volume, and fractional anisotropy (a measure of brain connectivity) compared to those with normal blood pressure. Furthermore, men with high blood pressure had lower scores than women.
This study adds to the increasing body of research that indicates that cardiovascular risk factors during young adulthood have a negative impact on brain health later in life.
The researchers acknowledged that due to the limited sample size, they were unable to investigate potential racial and ethnic disparities. They also advised caution when interpreting the findings related to sex differences. Additionally, the researchers noted that the MRI data was only obtained once late in life, which could only provide information about physical properties such as volumetric variations, rather than specific evidence of neurodegeneration over time.
The analysis “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,” adds senior author Rachel Whitmer.
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