If you have high blood pressure in your 30s, you may want to pay more attention to your brain health as you age. A new study suggests that having hypertension in early adulthood is associated with worse brain health in late life, especially for men.
The study, published in JAMA Network Open, compared brain scans of older adults who had high blood pressure between the ages of 30 to 40 with older adults who had normal blood pressure. The researchers found that the high blood pressure group had significantly lower regional brain volumes and worse white matter integrity. Both factors are associated with dementia and Alzheimer’s disease.
The research also showed that the negative brain changes in some regions — such as decreased grey matter volume and frontal cortex volume — were stronger in men. They note the differences may be related to the protective benefits of estrogen before menopause.
“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,” said first author Kristen M. George, an assistant professor in the Department of Public Health Sciences at UC Davis.
High blood pressure, also known as hypertension, is blood pressure that is higher than normal. A normal blood pressure level is less than 130/80 mmHg. The Centers for Disease Control and Prevention estimates that 47% of adults in the United States have hypertension. The rate of high blood pressure varies by sex and race. About 50% of men have high blood pressure compared to 44% of women. The rate of hypertension is about 56% in Black adults, 48% in white adults, 46% in Asian adults and 39% in Hispanic adults.
The researchers looked at data from 427 participants from two healthy aging studies that provided them with health data from 1964 to 1985 for a diverse cohort of older Asian, Black, Latino and white adults. They obtained two blood pressure readings from when the participants were between the ages of 30 to 40. This allowed them to determine if they had been hypertensive, transitioning to hypertensive or had normal blood pressure in young adulthood.
They then analyzed MRI brain scans of the participants taken around age 75 and measured various aspects of brain structure and function, such as regional brain volumes, white matter integrity and cerebral blood flow.
The results showed that having high blood pressure in early adulthood was associated with lower regional brain volumes and worse white matter integrity across multiple regions of the brain. These regions are involved in memory, executive function, language and motor control.
The study also found that men who had high blood pressure in their 30s had lower grey matter volume and frontal cortex volume than women who had high blood pressure in their 30s. Grey matter is the part of the brain that contains most of the nerve cells and is responsible for processing information. The frontal cortex is involved in planning, decision making, problem solving and personality.
“These findings suggest that men may be more vulnerable to the detrimental effects of high blood pressure on the brain for some brain regions,” said senior author Rachel Whitmer, a professor in the Department of Public Health Sciences at UC Davis and chief of epidemiology at Kaiser Permanente Northern California Division of Research.
The authors emphasize that treating hypertension in young and middle-aged adults may help prevent dementia and Alzheimer’s disease later on. They also recommend more research to understand the sex differences in the impact of high blood pressure on the brain.
“Prevention is key,” Whitmer said. “We need to identify people at risk for dementia early and intervene with effective treatments.”