A Monash University analysis suggests that low-dose aspirin may be associated with a substantially lower risk of dementia among older people with a particular genetic profile. In the analysis of genetic data from more than 13,500 participants in the ASPREE trial, people in the highest 20% of a platelet-related genetic score who took aspirin had about a 70% lower relative risk of dementia than those who took a placebo. However, they also faced a higher risk of major bleeding, and the researchers say the findings must be confirmed before aspirin can be considered for dementia prevention.
The findings were published in Alzheimer’s Disease and Dementia: Journal of the Alzheimer’s Association. Researchers examined whether genetic differences could help explain why aspirin appeared to affect dementia risk differently among participants in the landmark ASPREE trial, or Aspirin to Reduce Events in Older Adults.
Aspirin was linked to lower dementia risk in one genetic group
The most notable results involved genes associated with platelet counts. Platelets are small blood components that help form clots. The researchers investigated whether genetic variations linked to platelet levels could influence aspirin’s potential effects on dementia.
After assigning participants a genetic score related to platelet counts, the researchers compared dementia rates among those who received aspirin with rates among those who received a placebo.
Among participants in the top 20% of platelet-count genetic scores, 1% of aspirin users developed dementia, compared with 3.3% of those who took a placebo. This corresponds to an approximately 70% lower relative risk of dementia among people taking aspirin.
However, the apparent benefit was accompanied by a substantial safety concern. Within the same genetic group, 4.4% of aspirin users experienced major bleeding, compared with 2.1% of participants who received a placebo.
Genetic clues could influence dementia prevention
Lead author Dr Peter Franske, a research fellow at the Monash School of Public Health and Preventive Medicine, said the findings suggest that genetic makeup could eventually help determine which dementia-prevention strategies are most appropriate.
“Previous trials have shown that aspirin does not prevent dementia when everyone is considered together,” Dr Franske said.
“Our findings suggest there may be more to this story.
“In people with this particular genetic profile, cases of dementia were significantly reduced among people taking aspirin.
“Rather than taking a one-size-fits-all approach, this raises the possibility that genetics could one day help identify people who would benefit from preventive treatment.”
As dementia becomes more common, targeted prevention strategies could become increasingly important. Dementia Australia estimates that approximately 446,500 people in Australia will be living with the disease in 2026. That number is expected to exceed 1 million by 2065.
Platelets point to an unexpected connection with dementia
Previous research has linked dementia with platelet activation and aggregation, the process in which platelets become activated and adhere to one another. However, scientists do not yet fully understand how a person’s overall platelet count relates to dementia.
The new findings suggest that platelet biology may be an important area for further research. Notably, the genetic associations identified in the analysis did not include established genetic risk factors typically linked to Alzheimer’s disease and other forms of dementia.
“What is particularly interesting is that this signal is not associated with established genetic risk factors for Alzheimer’s disease or dementia,” Dr Franske said.
“Rather, it points us toward platelet biology and gives us new avenues to investigate.”
Why the findings do not yet support taking aspirin
The results suggest that aspirin’s effects may vary according to a person’s genes, but the researchers stress that the association must be confirmed before it can inform medical recommendations.
Researchers will first need to determine whether the findings appear in other populations. Clinical trials would then be needed to test aspirin specifically in people with the genetic profile identified in the analysis.
“We now need to confirm the findings in other studies and ultimately test it in trials specifically designed for people with this genetic profile.
“Based on this study, no one should start taking aspirin for dementia prevention without consulting their doctor, especially given the increased risk of serious bleeding.
“If this effect can be maintained, the fact that aspirin is already cheap and widely available could make personalized dementia prevention a realistic possibility.”
Source: www.sciencedaily.com