Fluctuating blood pressure could influence cognitive decline risk
- Previous research showed that blood pressure variability is linked to poorer thinking skills in white people.
- A new study extends these findings by examining the link in both white and Black people and compares the two groups.
- They show that this relationship is most pronounced in older Black men.
A recent study, which appears in the journal Neurology, focuses on thinking skills and blood pressure variability — in other words, how much blood pressure changes between visits to the doctor’s office.
The research team that conducted this study found that individuals with the highest variation in blood pressure over 18 years had the poorest scores in cognitive tests.
The relationship was most pronounced in older Black men, equating to an extra 2.8 years of cognitive aging in those with the most variable blood pressure.
How does blood pressure affect cognitive decline?
As people age, thinking skills tend to slow. This cognitive decline, however, is not inevitable, and it affects some people more than others.
Because the average age of the population is slowly increasing and the proportion of older adults in society grows, understanding the risk factors for cognitive decline is important.
Already, scientists have identified that high blood pressure, or hypertension,
More recently, scientists have also shown that
However, most of the research to date recruited mostly white people. That being the case, there is an urgent need to understand how this relationship plays out in Black people.
This is because, as the authors of the new study explain in their paper, "compared with white older adults, Black individuals experience a more significant burden of cardiovascular risk factors, particularly hypertension."
They write that this is likely due to a number of factors known as social determinants of health, which can include access to healthcare, socioeconomic status, and health literacy.
Black people with fluctuating blood pressure face higher cognitive decline risk
To investigate, the scientists who conducted the recent study took data from the Chicago Health and Aging Project, which included 4,770 individuals aged 65 or older (average age of 71.3). Of these, 66% were Black and the rest white.
These people were followed for 18 years and had their blood pressure measured every 3 years. They also completed four cognitive tests.
The researchers found that, on average, Black participants had more existing health conditions and were involved in less physical and cognitive activities. They were also more likely to be smokers.
To understand how they calculated blood pressure variability, below is a quick example using the systolic blood pressure readings of one participant with three checkups:
- Visit 1: 145 millimeters of mercury (mmHg).
- Visit 2: 160 mmHg
- Visit 3: 150 mmHg.
The difference between the first and second visit is 15 mmHg, and the difference between the second and third is of 10 mmHg. The two differences are then averaged which gives a mean difference of 12.5 mmHg.
The scientists found that, on average, Black people had systolic blood pressure variability of 17.7 mm Hg, compared with 16 mm Hg for white participants.
During their analysis, they split the participants into three groups — high, medium, and low blood pressure variation. They found that, overall, those in the high variability group had lower cognitive scores at their last visit.
For Black people, specifically, those in the high variability group had lower scores on the cognitive tests equivalent to 2.8 extra years of cognitive aging.
For white people, although the relationship was in the same direction, it was less pronounced and the results did not reach statistical significance.
Interestingly, the researchers also found that the associations were "independent of systolic and diastolic blood pressure." This means that even in individuals with relatively healthy blood pressure, the variation alone appears to be a risk factor for cognitive decline.
Controlling blood pressure can mitigate cognitive decline risk
"With our aging society and the prevalence of Alzheimer’s disease, identifying prevention strategies to slow the decline of cognitive skills in older adults has become a public health priority," explained study author Anisa Dhana, MD, from Rush University in Chicago, IL, in a press release.
"Managing blood pressure and its fluctuations is emerging as an essential risk factor that can be modified," she added.
Another important finding was that blood pressure variation was not linked to cognitive decline for individuals who were taking blood pressure medication. However, research shows that Black people with hypertension are
As mentioned, many factors likely influence cardiovascular risk in Black populations, but the authors hope that their findings "increase awareness in developing race-specific pharmacologic and nonpharmacologic treatment plans."
José Morales, MD is a vascular neurologist and neurointerventional surgeon at Providence Saint John’s Health Center in Santa Monica, CA, not involved in the current study.
Speaking to Medical News Today, he commented on whether blood pressure variation could one day be used as an early warning sign for cognitive decline risk.
"Absolutely [it could], but the tools to monitor these phenomena are still being developed,” he told us. "I suspect that the more dynamic variations throughout a given day may truly underly the mechanisms suspected to cause end-organ damage."
"Newer technology that allows for continuous blood pressure monitoring will be key to truly understanding ways to mitigate the harmful effects of hypertension," Morales concluded.
How to maintain a healthy blood pressure
As evidence mounts that hypertension is linked to cognitive decline, Alan Rozanski, MD, professor of medicine at the Icahn School of Medicine at Mount Sinai, who was not involved in the current study, offered some tips on how to maintain a healthy blood pressure.
He suggested:
- Limiting intake of highly processed foods:"These can raise LDL or "bad" cholesterol in multiple ways. Specifically, it’s important to limit or avoid fried foods like French fries and onion rings, processed meats such as bacon, sausage, hot dogs, and salami, as well as commercial baked goods like cookies, cakes, pastries, and doughnuts."
- Reducing excessive sodium intake:"There is some debate as to the ideal amount of sodium to consume in one’s diet, but most health organizations agree that excessive sodium intake — well above 2,300 milligrams per day — raises the risk of high blood pressure and heart disease."
- Getting regular exercise:"Regular exercise helps raise HDL "good" cholesterol, lower LDL cholesterol and triglycerides, and improve how your body uses fat."
- Managing stress levels:"Stress is a common part of life, but it becomes harmful when it leads to high emotional distress, feels uncontrollable, or persists at a high level over time. Try deep breathing, meditation, exercise, hobbies, spending time in nature, or seeking support from friends or counselors."
- Getting your blood pressure checked regularly:"Too many individuals have unrecognized high blood pressure. The sooner you know that you have this, the earlier you can institute healthy lifestyle changes that may help to lower your blood pressure."
Study limitations
The authors do acknowledge certain limitations to their study. For instance, because their study was conducted on participants in the south side of Chicago, the results may not be applicable to other regions or ethnic backgrounds.
Morales told MNT that these results support previous work, but because "the blood pressure measurements for this study are spread over pretty large intervals (i.e., years), there are likely to be confounding factors when looking at such complex pathophysiology."
In conclusion, the authors recommend routine assessment for blood pressure in Black people to help identify and potentially reverse cognitive decline.
Source
Fluctuating blood pressure: Who is most at risk of cognitive decline?
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