High blood pressure may be an accelerant of cognitive decline in middle-aged and older adults, according to research published in Hypertension.

Currently, approximately half of adults in the United States have high blood pressure or hypertension. Elevated blood pressure is defined as being 120 mmHg to 129 mmHg systolic pressure (the higher number on a reading) or greater. For hypertension, the systolic pressure reading would be above 130 mmHg and the diastolic pressure (the bottom number) reading would be 80 mmHg or higher.

"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," said study author Sandhi M. Barreto, MD, MSc, PhD, professor of medicine at the Universidade Federal de Minas Gerais in Brazil, in a press release. "We also found that effectively treating high blood pressure at any age in adulthood could reduce or prevent this acceleration. Collectively, the findings suggest hypertension needs to be prevented, diagnosed, and effectively treated in adults of any age to preserve cognitive function."

The study authors analyzed the results of previous research on blood pressure and cognitive health information for approximately 7000 adults in Brazil who were, on average, aged 59 years or older. In this prior research, the team had followed participants for approximately 4 years while testing their memory, verbal fluency, and executive function. This included tests on attention, concentration, and other areas associated with thinking and reasoning.

During the analysis of the data, the researchers in the new study observed that middle-aged and older participants with systolic blood pressure between 121 and 139 mmHg or diastolic blood pressure between 81 and 89 mmHg who were not taking antihypertensive medications had an accelerated rate of cognitive performance decline.

Additionally, this rate of cognitive decline happened regardless of the length of time participants had hypertension, as even a short period of experiencing hypertension affected a person's rate of cognitive decline. For this reason, those participants with uncontrolled hypertension demonstrated a significantly faster decline in memory and cognitive function than adults with controlled hypertension.

"In addition to other proven benefits of blood pressure control, our results highlight the importance of diagnosing and controlling hypertension in patients of any age to prevent or slow down cognitive decline," Barreto said in the press release. "Our results also reinforce the need to maintain lower blood pressure levels throughout life, since even prehypertension levels were associated with cognitive decline."

Barreto noted that the study's limitations may be its short follow-up period and the reliance on data from participants self-reporting a diagnosis of hypertension at baseline. However, Barreto explained that the results may still shed light on the impact of hypertension on cognitive decline.

"Although the participants of our study are adults from Brazil, we believe that our findings are applicable to other regions," Barreto said in the press release. “Previous studies have shown that similar unhealthy behaviors and risk factors, including hypertension, are common in the development of cardiovascular diseases in different populations across the globe.”

REFERENCE
High blood pressure at any age, no matter how long you have it, may speed cognitive decline. Dallas, TX: American Heart Association; December 14, 2020. https://www.eurekalert.org/pub_releases/2020-12/aha-hbp120920.php. Accessed January 19, 2020.