Dementia: How blood pressure fluctuations may increase risk

  • Blood pressure variability in midlife be linked to an increased risk of dementia for people in their 90s.
  • There is no consensus on whether and how to treat blood pressure variability.
  • During a person’s 60s, 70s, and 80s, high blood pressure is still a health risk factor.

Blood pressure variability rate for people in their 90s may be linked to an increased rate of dementia, according to a study published today in the journal JAMA Neurology.

In conjunction with researchers at Radboud University in the Netherlands, scientists at Kaiser Permanente Washington wanted to determine if blood pressure variability in midlife could be linked to an increased risk of dementia in later life.

The researchers analyzed 820 participants 65 to 90 years old. The participants underwent a medical assessment at the start of the trial, including a cognitive screening, and every 2 years after that.

All participants were 65 or over at the beginning of the trial, were community dwellers, and did not have dementia.

The data on participants was from the Adult Changes in Thought (ACT) study, an ongoing population-based study in the United States.

The researchers reported that the blood pressure variability rate was not associated with a higher lifetime dementia risk at 60, 70, or 80 years. However, for those in their 90s, the variability rate was associated with 35% higher dementia risk.

They added that high blood pressure is still a health risk factor for people 60 to 90 years old.

“The study shows that blood pressure variability as measured over annual visits spanning three decades was associated with risk of dementia in individuals who lived to be 90 years or older,” Dr. S Ahmad Sajjadi, a neurologist at UCI Health in California who was not in involved in the research, told Medical News Today. “Interestingly, the relationship between high systolic blood pressure and dementias reversed for younger vs. older old although this relationship never became statistically significant.”

Everyone has blood pressure fluctuations

Some level of blood pressure variability is common.

Everyone’s blood pressure rises and falls many times a day, according to Harvard Health. Sometimes it can fluctuate within minutes.

According to a report published in 2020 in the journal Hypertension, possible causes include Increased age, being female, body weight, cigarette consumption, alcohol, psychological stresses, vasoreactivity (as exemplified by response to cold exposure), target organ diseases such as left ventricular hypertrophy, chronic kidney disease, peripheral vascular disease, and subclinical atherosclerotic disease.

What is blood pressure variability

Blood pressure variability can be short-term, according to a report published in 2018 in the Journal of Clinical Hypertension.

The changes are usually divided into those without regular features and those with well-defined patterns over time. Besides dementia, these types of irregular blood pressure readings can be predictors of cardiovascular risk.

In the new study, hypertension was associated with a higher risk of developing dementia in a person’s 60s, 70s, and 80s. For people in their 90s, it was only blood pressure variability that was a higher risk factor.

“This study shows that blood pressure variability, rather than high blood pressure, could increase the risk of dementia,” said Dr. Shae Datta, the co-director of NYU Langone’s Concussion Center in New York and director of cognitive neurology at NYU Langone Hospital—Long Island. “This correlation was only seen at age 90 years – not younger than that. In order to keep the vessels in our heart and brain healthy, we must not stress them with variations in pressure.”

“This is a great long-term analysis of data in [blood pressure] variations of patients 65 years and older and assessment of dementia markers postmortem,” Datta, who was not involved in the study, told Medical News Today. “Patients can be counseled at older ages that it is advisable to control the variability in [blood pressure] to make sure there is less vascular insult.”

The researchers concluded that blood pressure variability indicated increased lifetime dementia risk in late life but not in midlife. This result suggests that the variability may indicate increased dementia risk in older age but might be less viable as a midlife dementia prevention target.

Strengths, limitations of dementia study

During the study trial period, 372 participants developed dementia. The scientists used autopsy information and medical records obtained from Kaiser Permanente Washington.

“I think there are limited time points of testing [blood pressure],” said Dr, José Morales, a vascular neurologist and neurointerventional surgeon at Pacific Neuroscience Institute in California who was not involved in the study. “I would like to see more consistency in getting the data. This information could influence the choice of medication.”

“The other limitation is that we don’t know about other factors, such as other health conditions and lifestyle factors. All of this could influence the outcome,” he told Medical News Today.

Experts said the major strengths of this study include the fact that blood pressure data was available for the same individuals for more than 30 years, along with the results of biennial cognitive assessment and dementia outcome confirmation by an adjudication committee.

Limitations are that autopsy data from consenting ACT study participants only was included. The participants were also mostly white and had access to relatively high-quality healthcare. Additionally, the variance in assessors could have inflated blood pressure variability estimates.

Treating blood pressure variability

An article published in 2022 addressed the question of whether blood pressure variability should be treated.

Calcium channel blocker decreased the variability, and ACE inhibitors, beta-blockers, and alpha-blockers increased it.

The study authors suggested that without research, medical professionals should work to control blood pressure overall.

However, this article addressed blood pressure variability as it relates to cardiovascular disease. As of now, there is limited research and no consensus on whether and how to treat the condition.

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