A study from University of Iowa researchers investigates the impact of low-dose aspirin on blood pressure in older adults. 

Previous research has shown that high-dose aspirin — especially when used regularly for an extended period — can lead to high blood pressure. Given that hypertension is a risk factor for cardiovascular disease and low-dose aspirin is commonly taken by older adults, Michael Ernst, clinical professor in the Department of Pharmacy Practice and Science, aimed to understand low-dose aspirin’s effect on blood pressure in people older than 65.

The individuals — 19,114 healthy adults from the United States and Australia — were enrolled in the ASPirin in Reducing Events in the Elderly (ASPREE) trial between 2010 and 2014 and followed for nearly five years. Participants were randomly given a low-dose aspirin tablet or a placebo. 

Neither the participants nor the researchers knew which trial subjects received which treatment. 

The participants’ blood pressure was measured annually for a median length of nearly five years. 

Ernst analyzed the ASPREE data and found there was no significant difference in blood pressure change between those who took the low-dose aspirin and those who took the placebo. 

The researchers also found from the data no significant difference in blood pressure change between the two groups when comparing only people who began the study with high blood pressure. There was also no difference in blood pressure change in people who were taking drugs to lower blood pressure at the beginning of the study or who began taking blood pressure-lowering drugs during the study period. 

Ernst sees the potential to expand the study. 

“Additional research could focus on isolating aspirin’s effect on blood pressure in those individuals with higher blood pressure to begin with, or those with significant cardiovascular comorbidities,” he says.

Ernst collaborated with Michelle Fravel, clinical professor in the Department of Pharmacy Practice and Science. The study, “Daily low-dose aspirin and blood pressure in community-dwelling older adults” was published online Aug. 26 in The Journal of Clinical Hypertension.

ASPREE was funded by the National Institute on Aging and the National Cancer Institute, branches of the United States National Institutes of Health. Additional funding came from Australian-based entities the National Health and Medical Research Council, Monash University, and the Victorian Cancer Agency.