A new study has found that people who feel dizzy when they stand up from lying down or sitting positions, are more at risk of developing dementia or stroke. The study was published in the latest issue of the journal Neurology.
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Feeling dizzy or light headed when getting up from a sitting or lying down position is due to a sudden fall in the blood pressure. This is known as orthostatic hypotension or postural hypotension. This mainly occurs when the blood pools in the lower extremities and the brain is temporarily deprived of oxygenated blood causing the light headedness. Common symptoms of orthostatic hypotension are feeling weak, confused, faint and mild nausea.
For this study the team of researchers recruited 11,709 people in the USA from the Atherosclerosis Risk in Communities (ARIC) study and found that they had a greater risk of getting dementia or stroke. The dizziness itself is not a symptom of any disease however. The study conducted by the American Academy of Neurology followed participants for an average of 25 years and the average age of the participants was around 54 years. None of these participants had an earlier history of a heart disease or stroke at the initiation of the study.
Andreea Rawlings, lead author of the study of Johns Hopkins Bloomberg School of Public Health in Baltimore, explained that orthostatic hypotension has been associated with heart disease earlier. This study explored the connection such type of hypotension has with brain disorders like stroke and dementia. She said this association could mean that patients developing orthostatic hypotension could be monitored closely for development of dementia and stroke in future. She added that more studies are needed to confirm the theory and also investigate preventive strategies.
Results from the study showed that among the 11,709 participants, 1,068 (9.1 percent) went on to develop dementia and 842 (7.1 percent) went on to have an ischemic stroke. Ischemic stroke occurs when the blood flow to particular part of the brain gets blocked depriving the region of oxygen. Among the 552 participants who had orthostatic hypotension at the start of the study 12.5 percent developed dementia and 15.2 percent developed ischemic stroke during follow up. Among the 10,527 participants who did not have orthostatic hypotension at the start of the study 6.8 percent had an ischemic stroke and 9 percent had dementia during the follow up.
Co-author Rebecca Gottesman, from Johns Hopkins explained that midlife orthostatic hypotention was never under the scanner before. Older people with orthostatic hypotension were focussed upon in connection with stroke, dementia and heart disease.
Dementia UK's chief executive and chief admiral nurse, Dr Hilda Hayo appreciated the study saying that it brings to notice that orthostatic hypotension can now be known as a potential risk factor for dementia in some individuals. Dr Shamim Quadir, research communications manager at the Stroke Association however said that orthostatic hypotension was only measured at the initiation of the study and this could be limitation of the study. Those developing orthostatic hypotension well into the study could also have been among those at high risk for dementia and stroke. He said more research would provide a deeper insight into this theory. He advised general population to get their blood pressure checked routinely.
This study was funded by the National Heart, Lung and Blood Institute, the NIH, and the National Institute of Diabetes and Digestive and Kidney Diseases.