People who feel faint, dizzy or lightheaded when standing up, caused by a sudden drop in blood pressure, may be at greater risk of developing dementia or stroke decades later, according to a study done by Johns Hopkins Bloomberg School of Public Health in the US.
The study, published in journal of the American Academy of Neurology, involved 11,709 people with an average age of 54, who were followed for 25 years. None had a history of heart disease or stroke at the beginning of the study.
“Orthostatic hypotension has been linked to heart disease, fainting and falls, so we wanted to conduct a large study to determine if this form of low blood pressure was also linked to problems in the brain, specifically dementia,” said Andreea Rawlings, from Johns Hopkins Bloomberg School of Public Health.
For the study, low blood pressure upon standing was defined as a drop of at least 20 millimetres of mercury (mmHg) in systolic blood pressure, which is the pressure in the blood vessels when the heart beats, or at least 10 mmHg in diastolic blood pressure, the pressure when the heart is at rest. Normal blood pressure is less than 120/80 mmHg. During the initial exam, participants were screened for orthostatic hypotension. They were instructed to lie down for 20 minutes and then stand up in a smooth, swift motion.
Researchers found those who had orthostatic hypotension at the beginning of the study had a 54% higher risk of developing dementia than those who did not have orthostatic hypotension at the beginning of the study.
“Measuring orthostatic hypotension in middle-age may be a new way to identify people who need to be carefully monitored for dementia or stroke,” said Rawlings. “More studies are needed to clarify what may be causing these links as well as to investigate possible prevention strategies,” she said.