High blood pressure at night increases dementia risk

09 February 2021

Researchers in Sweden have found that people with high blood pressure that gets even higher at night are at increased risk of dementia. The research was published in the scientific journal, Hypertension, today (Monday 8 February).

What is dipping?

A person’s blood pressure usually goes down at night. This phenomenon is known as dipping.

But for some people, particularly those with high blood pressure, night–time blood pressure can stay the same or even increase. This is known as reverse dipping.

Who did the scientists study?

The researchers looked at the effect of high blood pressure and night-time dipping status on people’s risk of dementia up to 24 years later. Participants were on average over the age of 70.

What did they find?

They found that reverse dipping was associated with a higher risk of being diagnosed with dementia, in particular Alzheimer’s disease but not vascular dementia.

What our expert said:

Dr Sara Imarisio, Head of Research at Alzheimer’s Research UK, said:
“High blood pressure is a strong risk factor for dementia. While age and genetics play an important role in dementia risk, research shows that up to 40% of dementia cases may be preventable if it were possible to eliminate a number of risk factors that include high blood pressure.

“This study suggests that it’s not just daytime blood pressure that may affect dementia risk but blood pressure changes between day and night. The phenomenon of reverse dipping, where blood pressure increases during the night, is an accepted measure of cardiovascular risk, but the effect this has on dementia risk is relatively under-studied.

“While this was a large study, the volunteers with high-blood pressure were older men and previous research suggests mid-life may be the crucial time to tackle risk factors like high blood-pressure and lower the risk of dementia.

“In times like these, it’s especially important we retain a healthy lifestyle for all aspects of our health. As well as maintaining a healthy blood pressure, the best evidence suggests that not smoking, only drinking in moderation, 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.

“We must do all we can to help reduce the number of people who will go on to develop dementia in future. That’s why Alzheimer’s Research UK has launched the Think Brain Health campaign as an important first step.”

Read more:

Hypertension: Reverse Dipping of Systolic Blood Pressure Is Associated With Increased Dementia Risk in Older Men