Orthostatic hypotension could contribute to risk of dementia

Written by Hannah Makin

Recent findings from researchers at the Johns Hopkins Bloomberg School of Public Health (MD, USA) have demonstrated that the rapid drops in blood pressure experienced when standing up from a sitting position (known as orthostatic hypotension) could lead to an increased risk of cognitive decline and dementia later in life.
These findings were presented in full at the 2017 Scientific Session held by the American Heart Association, 10 March 2017, in Portland (OR, USA).

This prospective study analyzed 11,503 participants from the Atherosclerosis Risk in Communities (ARIC) study cohort who were first tested between the years 1987 and 1989.

Of these participants (who were all aged 45– 64 at the time the first study began in 1987 and had no history of coronary heart disease or stroke), 703 displayed orthostatic hypotension upon standing up after 20 minutes of lying down.

Over 20 years, either cohort surveillance or cognitive and neurological testing allowed the researchers to identify whether a participant had developed dementia since the initial study. Cognitive decline was also measured via neuropsychological testing.

Postdoctoral researcher at the School and leader of this study, Andreea Rawlings, commented on these findings: “We found that those people who suffered from orthostatic hypotension in middle age were 40 percent more likely to develop dementia than those who did not. It’s a significant finding and we need to better understand just what is happening.”

However, scientists believe it is still too early to form reliable conclusions from these findings, as it is possible that orthostatic hypotension is a consequence of underlying disease, rather than the cause of it.

Additionally, the lack of retesting after the initial study ended means that scientists are now unsure whether these patients suffered recurrent orthostatic hypertension, or whether this was just a single occurrence during tests in the first experiment.

Therefore, further studies are required to reveal the true effects of orthostatic hypotension on long-term cognitive function.

As Rawlings commented: “Identifying risk factors for cognitive decline and dementia is important for understanding disease progression, and being able to identify those most at risk gives us possible strategies for prevention and intervention. This is one of those factors worth more investigation.”

Sources: Rawlings A, Juraschek S, Heiss G et al. Orthostatic hypotension is associated with 20-year cognitive decline and incident dementia: the Atherosclerosis Risk in Communities (ARIC) study. Circulation 135(Suppl. 1), A28 (2017); http://www.jhsph.edu/news/news-releases/2017/rapid-blood-pressure-drops-in-middle-age-linked-to-dementia-in-old-age.html