Elderly patients with sustained hypertension in midlife followed by hypotension in late life have a greater risk of dementia compared with people whose BP remains in the normal range, a study suggests.

The findings add to a growing body of evidence that aberrant BP patterns in middle age and beyond are a risk factor for future cognitive decline, the US researchers say.

More than 4700 participants enrolled in the ARIC (Atherosclerosis Risk in Communities) study during midlife had their BP data examined at a baseline visit between 1987 and 1989, and again at five subsequent visits over a 24-year period.

Participants also underwent detailed neurocognitive evaluation at the fifth visit, at a mean age of 75, and again at a mean age of 80.