Feel Dizzy When You Stand Up? Condition May Increase Risk of Dementia by Almost 40 Percent

People who have a condition which causes them to feel dizzy when they stand may be almost 40 percent more likely to develop dementia compared with those who don't, according to a study.

The authors of the paper published in the journal Neurology wanted to explore whether what is known as orthostatic hypotension could predict a person's chances of getting dementia.

Orthostatic hypotension is where a person's blood pressure drops significantly when they stand up, and has a range of causes. The most common symptom is feeling light headed when standing up.

The study involved 2,131 people aged 73 years old on average. Repeatedly over a period of five years, researchers tested their blood pressure after they stood up, and asked them to complete a cognitive test.

Blood pressure is measured in two ways: Systolic, or the pressure in the arteries when the heart beats and fills up with blood, and the diastolic, or the pressure in the arteries when the heart is resting between beats. The normal range for blood pressure is less than 120 systolic and less than 80 diastolic.

A person was deemed to have orthostatic hypotension in the study if their blood pressure was equal or greater than 15 systolic and 7 diastolic after standing for a sitting position in one or more out of three visits.

The team then observed whether the participants developed dementia over a 12 year period, according to whether they had a prescription of dementia medication, their hospital records, or if they scored lower in a cognitive function test.

Of the total participants, 309 had orthostatic hypotension, and 462 developed dementia. After adjusting the data for factors that might skew the results, the team found systolic orthostatic hypotension were linked to an "almost 40 percent" greater risk of dementia.

The study was observational, so couldn't prove that the condition causes dementia, the team said. But they said there may be several explanations for the link, including that it may reduce the amount of blood flow to the brain.

The findings were also limited because the diagnosis of dementia was not based on formal and structured clinical assessment.

Dr. Laure Rouch of the Centre for Population Brain Health at the University of California, San Francisco, said in a statement: "People's blood pressure when they move from sitting to standing should be monitored.

"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."

Sara Imarisio, head of research at Alzheimer's Research U.K. who did not work on the study, told Newsweek: "Research shows that the brain doesn't operate in isolation from the rest of the body. This research suggests that low blood pressure could be associated with a greater risk of dementia. It's important that researchers build on this to get to the bottom of the mechanisms underlying this risk.

Imarisio said: "As well as maintaining a healthy blood pressure, the best current evidence suggests that not smoking, drinking within the recommended guidelines, staying mentally and physically active, eating a balanced diet, and keeping cholesterol levels in check can all help to keep our brains healthy as we age."

A separate study published in the journal Hypertension on Monday found high blood pressure may put a person at risk of developing cerebral small vessel disease, an umbrella term for conditions that affect the brain's blood vessels.

It is the most common form of disease relating to the brain and its blood vessels underlying dementia, as well as stroke, the team said. The study involved 1,686 people.

This article has been updated with comment from Sara Imarisio.

dizzy, light-headed, stock, getty
A stock image shows a woman experiencing dizziness. Scientists have explored the link between a condition that causes dizziness and dementia.