It is very common that, after sitting for a while and getting up quickly, we suffer slight dizziness and that feeling of numbness and heaviness in the head that is so annoying. People who feel lightheaded or dizzy when getting up may experience a sudden drop in blood pressure called orthostatic hypotension . A new study by the academic journal of the American Academy of Neurology indicates that middle-aged people who suffer from such drops in blood pressure may be at higher risk for dementia or stroke .
Orthostatic hypotension has already been linked to heart problems, fainting and falls, but the new research, led by Dr. Andreea Rawlings of the John Hopkins Bloomberg School of Public Health , seeks to determine if this form of low blood pressure is related to brain problems, specifically dementia. For the correct conduct of the study, it was established that it would be considered low blood pressure when there was a minimum drop of 20 millimeters of mercury (mmHg) in systolic blood pressure , when the heart contracts to produce a beat; or 10 mmHg in diastolic blood pressure , when the heart is at rest. Normal blood pressure is less than 120/80 mmHg .
The study was conducted with 11,709 people with an average age of 54 years followed by a group with an average age of 25 years. The participants met up to five times with the researchers during the study. None of them had a history of heart problems or strokes at the beginning of the study.
During the initial examination, the participants were evaluated for orthostatic hypotension. They were instructed to lie down for 20 minutes and then get up in a fast, fluid motion . Blood pressure was measured five times when standing up. The researchers determined the average of the readings and calculated the difference from the average blood pressure of the participants at rest. 522 participants, 4.7% , were found to have orthostatic hypotension at the beginning of the study.
The researchers monitored the participants during the study for signs of dementia or strokes with visits and reviewing medical records. During the study, 1,068 people developed dementia and 842 people suffered an isthremic stroke, which happens when blood flow is blocked in part of the brain . Those participants who had orthostatic hypotension at the beginning of the study were found to have a 54% higher risk of developing dementia than the others. A total of 999 of the 11,156 participants without orthostatic hypotension ( 9% ) developed dementia, compared with 69 of 552 subjects with orthostatic hypotension ( 12.5% ).
In addition, those with orthostatic hypotension were twice as likely to have an isthremic stroke. 15.2%, or 84 of 552 people, with orthostatic hypotension suffered an isthremic stroke; compared to 758 of 11,157 people ( 6.8% ). No association with blood effusions was observed.
“Measuring orthostatic hypotension in middle-aged people may be a new way to identify people who need careful monitoring for dementia or strokes, ” says Rawlings. “More studies are needed to clarify the cause of this relationship, as well as to investigate new prevention strategies .”
Referencia: Andreea M. Rawlings, Stephen P. Jurascheck & team. ‘Association of orthostatic hypotension with incident dementia, stroke, and cognitive decline’. Neurology® (2018). DOI: https://doi.org/10.1212/WNL.0000000000006027
