A preliminary new study has found that having high blood pressure later in life may speed up cognitive decline, but treating the condition may also help slow it down.
Carried out by researchers at Columbia University Mailman School of Public Health, USA, the new study looked at data gathered from nearly 11,000 adults in China to assess how high blood pressure and its treatment may be linked with cognitive decline.
The researchers interviewed each of the study participants about their high blood pressure treatment and asked them to perform cognitive tests, such as recalling words as part of a memory quiz.
High blood pressure was defined as having a systolic blood pressure of 140 mmHg or higher and a diastolic blood pressure of 90 mmHg or higher, and/or taking antihypertensive treatment. The American Heart Association defines high blood pressure as starting with slightly lower measurements, and having a systolic blood pressure of 130 mmHg or higher or a diastolic reading of 80 mmH or higher.
The findings, presented at the American Heart Association's Hypertension 2019 Scientific Sessions, showed that overall, cognition scores declined over the four-year study. However, participants who were age 55 and older and who had high blood pressure showed a quicker rate of cognitive decline compared with those who did not have high blood pressure or who were being treated for high blood pressure.
In fact, the rate of cognitive decline was similar between those without high blood pressure and those taking treatment for the condition.
As an observational study, the researchers cannot establish cause and effect. The team also did not investigate why or how high blood pressure treatments may have slowed down cognitive decline, or which treatments were the most effective.
Nevertheless, senior author L.H. Lumey commented that, "The findings are important because high blood pressure and cognitive decline are two of the most common conditions associated with aging, and more people are living longer, worldwide."
Study author Shumin Rui also added, "We think efforts should be made to expand high blood pressure screenings, especially for at-risk populations, because so many people are not aware that they have high blood pressure that should be treated."
"This study focused on middle-aged and older adults in China, but we believe our results could apply to populations elsewhere as well. We need to better understand how high blood pressure treatments may protect against cognitive decline and look at how high blood pressure and cognitive decline are occurring together."