Most people's blood pressure drops at night, which doctors call "hypotension.". But for people with high blood pressure, their nighttime blood pressure will remain unchanged or even rise. People with high blood pressure and elevated blood pressure at night may be more likely to have vascular disease and memory problems associated with damaged middle brain regions, a new study suggests. The study was published in the April 15, 2020 issue of Neurology.
"These results provide additional evidence of the importance of vascular risk factors in promoting memory problems," said study author Dr. Adam M. Brickman of Columbia University. "Efforts such as maintaining a healthy weight, being active and having a healthy diet can effectively prevent the potential effects of hypertension. "
The study involved 435 people with an average age of 59 who participated in an aging study in Venezuela. Their blood pressure was monitored at home with a device for 24 hours, every 15 minutes during the day and every 30 minutes at night. They also performed brain scans to look for areas of the brain associated with impaired white matter hyperplasia. The participants also tested memory and other thinking abilities.
Most of the participants (59%) had high blood pressure, i.e. the average blood pressure was more than 130 / 80 mmHg, or were taking high blood pressure drugs. In half of the participants, blood pressure dropped at night, 40% remained unchanged and 10% increased.
The researchers found that after adjusting for age, people with high blood pressure and elevated nighttime blood pressure had more than twice as much white matter hyperplasia as other participants. The white matter change of the former group averaged more than 6 cubic centimeters, while the other participants averaged only 2.5 cubic centimeters or less.
Those with high blood pressure and high blood pressure at night also scored lower on memory tests than other participants. Their average score was about 33, while that of other participants was about 40.
"Elevated blood pressure at night may amplify the effects of hypertension on cerebrovascular health and related cognitive abilities," Brickman said. "We need longer, over time studies to determine whether these factors actually lead to white matter change and memory problems, although our preliminary findings do agree with this hypothesis," Brickman said. He pointed out that the study only included middle-aged and elderly people, so the results may not apply to people of other ages.
