Hypertension Linked to Cognitive Decline, but Treatment Helps

Caroline Helwick

September 19, 2019

NEW ORLEANS — Hypertension appears to accelerate cognitive decline, but effective treatment slows this process, reducing the risk virtually to the level of people without hypertension, an analysis of a large database from China suggests.

"Within each age group, patients with hypertension who were untreated had the fastest cognitive decline, while subjects without hypertension declined the least. The greatest declines were seen in persons aged 65 and older," reported Shumin Rui, MS, a biostatistician at who conducted the work while at the Mailman School of Public Health at Columbia University, New York City. Rui is now employed by IQVIA Biotech, Boston.

The results were presented here at the American Heart Associations Hypertension 2019 Scientific Sessions.

CHARLS Study

In this observational study, researchers from Columbia University analyzed data for 10,958 adults from the China Health and Retirement Longitudinal Study (CHARLS) obtained between 2011 and 2015. The survey contains health and demographic information.

The researchers defined hypertension as a systolic blood pressure (SBP) of at least 140 mm Hg, a diastolic blood pressure (DBP) of at least 90 mm Hg, and considered anyone taking antihypertensive medication to be hypertensive. Blood pressure was measured three times and then averaged.

Cognition was assessed with an episodic memory test (immediate and delayed recall of 10 nouns; scale, 0–10) and tests of mental intactness (Telephone Interview of Cognition Status [TICS]; scale, 0–11). The results were combined to form a Global Cognition Score (scale, 0–21).

Participants were categorized by age (45–54 years, 55–64 years, at least 65 years) and hypertension status (hypertensive or not; treated or untreated). They were followed for 4 years, and the 2011 and 2015 outcomes were compared.

Cognition Declined With Hypertension

The main findings were these:

  • Overall scores on cognitive tests declined over the 4-year study.

  • Participants 55 years and older with untreated hypertension had a more rapid rate of cognitive decline than participants with hypertension that was treated and than those without hypertension.

  • Rate of cognitive decline was similar between participants receiving antihypertensive medications and those with no hypertension.

For the whole population, overall cognition scores declined significantly, from a mean of 11.01 in 2011 to 10.24 in 2015 (P < .01), with the most striking changes in the oldest age group (at least 65 years). Although people 45 to 54 years of age exhibited cognitive decline as well, for all the hypertension groups, their changes were smaller.

Compared with participants without hypertension, on the scale of 0 to 21, those with hypertension that was not treated had mean decline that was 0.65 points greater in the oldest group, 0.31 points greater in people 55 to 64 years, and 0.14 points greater in those 45 to 54 years.

The older the participant, the lower the cognitive score," Rui said. "Across the different age groups and different hypertension and treatment groups, cognition declined, but it declined faster in older patients. It shows the impact of age on cognition, even over a period as short as 4 years."

Strong Treatment Effective

The positive effect of treating hypertension was evident when people with treated hypertension were compared with those with untreated hypertension and normotension. On average, all groups experienced cognitive decline, but those with treated hypertension had an advantage over those who were untreated; their decline was marginally less than those with no hypertension at all and, in the oldest group, only slightly worse.

Treatment led to a slower decline — by about a half point on the Global Cognition Score scale — on the year 4 exam.

"Hypertensives with treatment maintained their cognition 'this' much better on the scale of 0 to 21, versus others," explained senior investigator L.H. Lumey, MD, MPH, PhD, professor of epidemiology at Columbia.

Table. Differences in Cognitive Decline: Treated Hypertension Compared With the Other Groups
Age Group Untreated Hypertension No Hypertension
45–54 years +0.57 +0.26
55–64 years +0.57 +0.25
≥65 years +0.56 –0.11

"Treatment of hypertension helped participants have smaller cognitive declines than their counterparts without treatment, and compared with participants without hypertension at all, treatment seemed to make cognitive changes comparable," Rui explained.

Results were similar after adjustment for education, gender, and residency (urban vs rural). These factors, along with smoking and drinking status, socioeconomic and marital status, and body weight, did not have a significant impact on cognitive decline, she said.

Rui said the findings confirm hints from other studies that hypertension can add to cognitive decline. "We suggest that early detection and treatment of hypertension can help stop this."

High Interest in Findings

Listeners at the session found the study results compelling and concerning. "It's amazing how much cognitive decline they saw in everyone, in their 40s, 50s, and 60s. That's not even old!" commented Sandra J. Taler, MD, professor of medicine, Mayo Clinic, Rochester, Minnesota.

Taler and others were interested in which antihypertensives participants were taking.

"Do you have data on which drugs? Because studies from Taiwan indicate that patients who happen to take ARBs [angiotensin receptor blockers] are much less likely to experience cognitive decline in follow-up," said Christopher Wilcox, MD, director, Hypertension Research Center, Georgetown University Medical Center, Washington, DC.

The investigators report that they will eventually compare Western medicine with "traditional Chinese medicine," but that is all the information they have on treatment.

Taler said she would also like to see the cognition scores that were obtained in 2013 on the interim visit. "Trend numbers might be more reliable if we had these intervening points," she said. "If the data trend in the same way, the statistics may be stronger."

She cautioned that this is an observational study, with self-reported hypertension treatment and no specifics on which drugs were taken. Nevertheless, she said this is important information for everyone, including the concern over cognitive decline in general. "We're actually all up against that wall," she commented.

Rui, Lumey, Taler, and Wilcox had no relevant disclosures.

Hypertension 2019 Scientific Sessions: Abstract 004. Presented September 5, 2019.

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