Older adults who have high blood pressure at night relative to daytime are at an additional risk of developing Alzheimer's disease, an incurable and fatal form of dementia in which brain tissue is destroyed. This is the conclusion reached by Swedish researchers who published an article in the journal Hypertension.
The relationship between daytime and nighttime systolic blood pressure is known to be a predictor of future health problems, including decreased mental performance. In healthy people, blood pressure decreases at night (this phenomenon is called dipping) by 10-20 percent, and doctors call a decrease of less than 10 percent (non-dipping) an alarming sign indicating a high risk of an adverse event from the cardiovascular system.
In the new work, scientists tried to associate with possible diseases not only a small drop in pressure, but, on the contrary, its higher indicators at night (reverse dipping). They analyzed data on about a thousand elderly Swedish men over 60, whose health was monitored by doctors for at least 24 years. 24-hour ambulatory blood pressure monitoring was performed at a mean age of 71 and 77.6 years. The incidence of dementia was determined based on the patient's medical history and confirmed by two experienced geriatricians.
A high night-to-day systolic blood pressure ratio was found to be associated with a 1.64-fold increase in the average risk of any dementia and a 1.67-fold increase in Alzheimer's disease. Conversely, non-dipping did not increase the likelihood of cognitive impairment.
It remains to be seen whether drugs that lower nighttime pressure below daytime levels can significantly curb future dementia, the researchers said.
