Drops in blood pressure linked to higher dementia risk

October 27, 2023—Orthostatic hypotension (OH)—a sudden drop in blood pressure upon standing up, resulting in dizziness—may be linked to a higher risk of developing dementia, according to a new study led by Harvard T.H. Chan School of Public Health.

The study was published on October 23 in Hypertension.

Previous research has pointed to an association between OH and dementia. To further explore the link, researchers used data on 11,644 adults who were on average 55 years old and participated in the Atherosclerosis Risk in Communities Study, which began in the late 1980s. Participants’ blood pressure was taken while lying down and then five more times in the first two minutes after they stood up. Their health was then monitored for the next decades. After a median of 26 years, one in five of the participants had developed dementia. The researchers observed that those whose systolic blood pressure dropped by at least 20 mmHg—enough for them to feel dizzy—in the first 30 seconds after standing had a 22% higher risk of developing dementia compared to those who did not experience OH.

“These early drops in blood pressure usually are not checked when patients go to their doctors,” Yuan Ma, lead author and assistant professor of epidemiology, told the American Heart Association in an October 23 article. “This study suggests that doctors need to pay more attention to these early abrupt drops in blood pressure because they could be a sign that someone is at a higher risk of developing dementia.”

She added, however, that the study only indicates an association, rather than causation—and that more research is needed to understand the brain’s role in OH.

Study co-authors Yiwen Zhang, doctoral student; Chelsea Liu, PhD ’22; Deborah Blacker, professor; and Albert Hofman, professor and department chair, all affiliated with the Department of Epidemiology.

Read the article from the American Heart Association: Feel dizzy when you stand up? It’s a drop in blood pressure and may be an early sign of dementia