Feel lightheaded when standing up? You may have a greater risk of dementia

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People who feel faint, dizzy or lightheaded when standing up may be experiencing a sudden drop in blood pressure called orthostatic hypotension. Now a new study says middle-aged people who experience such a drop may have a greater risk of developing dementia or stroke decades later. The study is published in the July 25, 2018, online issue of Neurology, the medical journal of the American Academy of Neurology.

"Orthostatic hypotension has been linked to , 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 study author Andreea Rawlings, Ph.D., MS, of Johns Hopkins Bloomberg School of Public Health in Baltimore, Md.

For this study, upon standing was defined as a drop of at least 20 millimeters of mercury (mmHg) in , which is the pressure in the blood vessels when the heart beats, or at least 10 mmHg in , the pressure when the heart is at rest. Normal blood pressure is less than 120/80 mmHg.

The study involved 11,709 people with an average age of 54 who were followed for an average of 25 years. Participants met with researchers up to five times over the course of the study. None had a history of heart disease or stroke at the beginning of the study.

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. Blood pressure was taken five times upon standing. Researchers determined the average of the readings and then calculated the difference from the participant's average resting . Researchers determined that 552 participants, or 4.7 percent, had orthostatic hypotension at the start of the study.

Researchers monitored participants throughout the study for dementia and stroke with study visits and by reviewing medical records. During the study, 1,068 people developed dementia and 842 people had an ischemic stroke, which is a stroke where blood flow is blocked to part of the brain.

Researchers found those who had orthostatic hypotension at the beginning of the study had a 54 percent higher risk of developing dementia than those who did not have orthostatic hypotension at the beginning of the study. A total of 999 of the 11,156 without orthostatic hypotension, or 9 percent, developed dementia, compared to 69 of the 552 people with orthostatic hypotension, or 12.5 percent.

In addition, those with orthostatic hypotension had twice the risk of ischemic stroke. A total of 15.2 percent, or 84 of 552 people, with orthostatic hypotension had an , compared to 6.8 percent, or 758 of 11,157 people without orthostatic hypotension. There was no association with bleeding strokes.

"Measuring orthostatic in middle-age may be a new way to identify people who need to be carefully monitored for or stroke," said Rawlings. "More studies are needed to clarify what may be causing these links as well as to investigate possible prevention strategies."


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Journal information: Neurology

Citation: Feel lightheaded when standing up? You may have a greater risk of dementia (2018, July 25) retrieved 20 October 2019 from https://medicalxpress.com/news/2018-07-lightheaded-greater-dementia.html
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