There have been some articles in the press recently about Gliclazide (sulphonylureas), which is a drug used by some people to help control diabetes, and the increased risk of heart failure.
What did this study find?
- Researchers compared the risk of heart failure and heart attacks in people with type 2 diabetes whose first and only medication was either a sulphonylurea (like gliclazide) or metformin.
- They found a small increase in the risk in people started on sulphonylureas (like gliclazide).
- The increased risk was relatively small with 4 incidents of heart failure in every 1000 people started on sulphonylureas.
What does this study mean for me?
- These results do not apply to people taking both metformin and sulphonylurea together.
- The results of this study only apply to a small number of people. UK guidelines advise that people should be started on metformin first unless there is a good reason not too (like very low kidney function or problems with side-effects).
- Increasing weight may be the reason why sulphonylureas increase the risk of heart problems, so it may be possible to counteract this by eating healthily and being physically active.
- No-one should stop taking sulphonylureas based on these results.
How did they do this study?
The researchers looked at the medical records of 139,172 people in America with type 2 diabetes who had been started on either metformin or a sulphonylurea (like gliclazide). They matched people so they had similar risks of having heart failure or heart disease.
The researchers then looked at the number of people who had to be admitted to hospital with heart failure or died from heart problems in a 10 year period from 2001-2011.
They found that in 1 year, for every 1000 people taking a sulphonylurea there were 12.4 such events, compared to 8.9 events in people taking metformin. That’s an extra 3.5 events, meaning that in every 1000 people who were given a sulphonylurea as their first and only medication for diabetes, 3.5 more had a hospital admission or died than in every 1000 people given metformin as their first and only medication for diabetes.
The study has a number of limitations. Only 3% of participants were women and 97% were men so we don’t know whether this result is relevant for women. It is also a retrospective study that looked back on old data so the results are lower quality and at a higher risk of bias than a randomized trial.
You can find the original article in the Journal of the American Heart Association.