A person is may have an increased risk of developing dementia in future if he feels dizzy or light-headed while standing up, according to a new study which has been published in Neurology, the medical journal of the American Academy of Neurology.
The condition, called orthostatic hypotension, occurs when a person experiences a sudden drop in blood pressure when he or she stands up.
The study found the link with dementia only in people who have a drop in their systolic blood pressure, not in people with only a drop in their diastolic blood pressure or their blood pressure overall.
Systolic is the top, or first, number in a blood pressure reading and systolic orthostatic hypotension was defined as a drop of at least 15 mmHg after standing from a sitting position.
“People’s blood pressure when they move from sitting to standing should be monitored,” said study author Laure Rouch, Pharm.D., Ph.D., of the University of California, San Francisco.
“It’s possible that controlling these blood pressure drops could be a promising way to help preserve people’s thinking and memory skills as they age,” Rouch added.
2,131 people, who were an average age of 73, were part of the study and they did not have dementia when they were enrolled. Their blood pressure readings were taken at the start of the study and then one, three and five years later. A total of 15 per cent of the people had orthostatic hypotension, 9 percent had systolic orthostatic hypotension and 6 percent had diastolic orthostatic hypotension.
Over the next 12 years, the participants were evaluated to see if anyone developed dementia. A total of 22 percent, or 462 people, did develop the disease.
The people with systolic orthostatic hypotension were nearly 40 percent more likely to develop dementia than those who did not have the condition. Fifty of the 192 with systolic orthostatic hypotension, or 26 percent, developed dementia, compared to 412 of the 1,939 people without it, or 21 percent.
When researchers adjusted for other factors that could affect dementia risk, such as diabetes, smoking and alcohol use, those with systolic orthostatic hypotension were 37 percent more likely to develop dementia.
The researchers also found that people whose sitting-to-standing systolic blood pressure readings changed the most from visit-to-visit were more likely to develop dementia years later than people whose readings were more stable.