Faster Cognitive Decline Linked with Midlife, Older Hypertension

Global cognitive scores fell faster among middle-age and older adults who had hypertension or pre-hypertension than those who didn’t, a longitudinal study suggested.

In people both younger and older than age 55, both hypertension and pre-hypertension (systolic blood pressure between 121-139 mm Hg or diastolic blood pressure between 81-89 mm Hg) were linked with declining cognitive performance, after adjusting for confounding variables, reported Sandhi Barreto, MD, PhD, of Universidade Federal de Minas Gerais in Belo Horizonte, Brazil, and colleagues, in Hypertension.

Hypertension duration was not an independent predictor of longitudinal cognitive performance. Controlled hypertension appeared to reduce cognitive decline pace, the researchers said.

“We initially anticipated that the negative effects of hypertension on cognitive function would be more critical when hypertension started at a younger age, however, our results show similar accelerated cognitive performance decline whether hypertension started in middle age or at older ages,” Barreto said in a statement.

“We also found that effectively treating high blood pressure at any age in adulthood could reduce or prevent this acceleration,” Barreto added. “Collectively, the findings suggest hypertension needs to be prevented, diagnosed and effectively treated in adults of any age to preserve cognitive function.”

Blood pressure that “many of us would consider just borderline can be associated with memory problems and other cognitive impairment as we get older,” said Roger Blumenthal, MD, of Johns Hopkins Hospital in Baltimore, who wasn’t involved with the study.

“Often, clinicians and patients look at borderline pressures and think it’s close enough and not a big problem,” he told MedPage Today. “But these researchers were able to show evidence of cognitive decline as time went on. Some of these findings are more subtle, but they’re meaningful.”

The findings dovetail with data from the MESA cohort that showed atherosclerotic cardiovascular disease risk started climbing far below the threshold for hypertension, Blumenthal added.

In their analysis, Barreto and colleagues assessed data from 7,063 participants in the ELSA-Brazil cohort at two visits, the first in 2008-2010 and the second in 2012-2014. More than half (55.2%) were women and 15.3% were Black. At the first visit, participants had a mean age of 58.9. Blood pressure was measured at each visit; participants self-reported their age at hypertension onset when they entered the study. Cognitive performance was evaluated at both visits and was based on memory, verbal fluency, trail B tests (which assessed attention, concentration, and mental flexibility), and global cognitive scores. The average interval between visits was 3.8 years.

Overall, 22.0% of participants had pre-hypertension and 46.8% had hypertension. Of hypertensive individuals, 29.8% were diagnosed at middle age and median hypertension duration was 7 years. Of participants who reported hypertension at the first visit, 7.3% did not use antihypertensive medication; of treated hypertensive participants, 31.2% had uncontrolled blood pressure levels.

Pre-hypertension was an independent predictor of downturns in verbal fluency and global cognitive scores as participants aged from the first to the second visit, compared with normal blood pressure.

Hypertension was associated with the greatest declines in memory, fluency, and global cognitive scores. Middle-age (under age 55) hypertension was associated with a drop in memory test scores. Older-age hypertension was linked with declines in both memory and global cognitive scores. Hypertensive participants with uncontrolled blood pressure had sharper declines in memory and global cognitive scores than people with controlled hypertension.

While the data didn’t support an adverse link between hypertension duration and cognitive performance, “other studies with longer term follow up may very well identify duration as being a contributor,” Blumenthal noted. “So even though they didn’t find it in their study of 7,000, it stands to reason that the longer you have mild hypertension, the greater the impact it’ll probably have.”

Cognitive performances were compared in only two visits: this was a limitation of the study, Barreto and colleagues acknowledged. The study population also was relatively young, had a high level of education, and had been followed for a relatively short time.