(Reuters Health) – A new large-scale study of fish oil and aspirin in diabetics has revealed that the oil supplements do not for the first time prevent heart attacks or strokes, but aspirin does, although the benefit of aspirin therapy is due to a higher risk of lifted unwanted bleeding.
Nearly 15,500 volunteers were tested to see if treatment made a difference. None of them had heart disease at the beginning of the study, but all had diabetes, which typically increases the risk of cardiovascular problems two to threefold.
The results of the ASCEND study were published on Sunday at the Annual Congress of the European Society of Cardiology in Munich and online in the New England Journal of Medicine.
In the fish oil part of the study, half of the patients took a daily 1
Participants were followed for an average of almost 7.5 years. During this time, 9.2 percent of the placebo-taking patients died of heart disease, suffered a non-fatal heart attack or stroke, or suffered a mini-stroke known as transient ischemic attack or TIA. The rate among fish oil recipients was 8.9 percent, a statistically insignificant difference.
Similarly, fish oil did not reduce the risk of reopening a blocked artery. This procedure was performed in 11.5 percent in the placebo group and 11.4 percent in the fish oil group.
When all the causes of death were investigated, the story was the same, with 9.7 percent in the fish oil group dying during the study, compared with 10.2 percent with olive oil placebo, another insignificant difference.
"The study provides much-needed clarity on the benefits of fish oil supplements for people with diabetes, but without a history of cardiovascular disease," said co-author Dr. Louise Bowman in an email to Reuters Health. "The fish oil supplements were safe, but offered no added benefit."
Dr. Bowman, professor of medicine and clinical trials at the Nuffield Department of Public Health at Oxford University, said, "There are ongoing studies looking at the effects of higher doses and it remains to be seen if there is a higher dose."
But she said, "a higher dose can not be well tolerated by patients."
In the aspirin study, people who took 100 milligrams daily had a lower rate of cardiovascular events, with rates of 8.5 percent for aspirin and 9 , 6 percent with matching placebo – in this case a statistically significant difference.
But the chances of bleeding – including brain, stomach, eye or other major bleeding – were also higher: 4.1 percent with aspirin versus 3.2 percent with placebo.
Thus, while aspirin reduced the likelihood of major cardiovascular events by 12 percent, it increased the risk of major bleeding n by 29 percent.
"The absolute benefits were largely offset by the risk of bleeding," said the team. Jane Armitage, Professor of Clinical Trials and Epidemiology in Nuffield.
The risk of fatal bleeding was the same in both groups.
The benefits of aspirin for people with heart disease are well known.
As for people without heart disease, "There is already strong evidence that if you are healthy and have no heart attacks, strokes, or circulatory disorders, the increased risk of aspirin bleeding outweighs the small benefit of preventing heart attacks and strokes," said Dr Armitage, "We have now shown that the same goes for people with diabetes who did not have circulatory problems."
In general, the aspirin result is "good news for patients that they do not have to take an extra tablet." Dr. Armitage said, "This may allow some patients to stop aspirin and avoid the continual risk of bleeding."
Dr. Bowman said that the ASCEND study was unique because it was "one of the largest studies on diabetes ever and give important information about two medical treatments, aspirin and fish oils. However, it has been designed to be highly cost-effective, using mail-based approaches to provide reliable information relevant to diabetes for the world's 400 million people, at a fraction of the cost of most major clinical trials. "
SOURCE: bit.ly 2ockatf and bit.ly/2wpvntZ The New England Journal of Medicine, online August 26, 2018.