HYPERTENSION is associated with a lower risk of dementia in people aged ≥90, according to the results of research from the University of California Irvine, Irvine, California, USA.
These new findings challenge the idea that high blood pressure and other heart health risk factors increase the risk of dementia. “In this first-of-its-kind study, we find that hypertension is not a risk factor for dementia in people age 90 or over, but is actually associated with reduced dementia risk,” said Prof Maria Corrada from the Department of Neurology, University of California Irvine, who was lead author of the recent paper. “This relationship had not yet been examined in groups of older people in their 80s or 90s, known as the ‘oldest old’.”
For the study, Prof Corrada and colleagues studied 559 people for an average of 2.8 years to investigate possible links between dementia and blood pressure. At the time of enrolment, participants did not have dementia and the average age was 93 years old. At follow-up, 224 (40%) participants were diagnosed with dementia.
The team found that participants who had reported hypertension onset in their 80s were 42% less likely to develop dementia after age 90, compared to those with no history of high blood pressure. Those whose hypertension began in their 90s had an even lower risk of developing dementia at 63%.
“Before we can make the leap to suggesting changes to blood pressure recommendations for reducing dementia risk in clinical care, we need more research to confirm and explain our findings,” explained Prof Corrada. “This includes investigations into the underlying biology of hypertension and brain function”.
Prof Corrada and the team suggest several explanations for the observed association between hypertension and dementia risk. These include the idea that the level of blood pressure needed to maintain an adequate blood flow in the brain for normal cognition may be altered in older age.
Jack Redden, Reporter