What Do We Know?
Diabetes and obesity are two conditions that can raise the risk for both heart disease and blood clots. Now, a new class of medications called glucagon-like peptide-1 receptor agonists (aka GLP-1s) has been getting a lot of attention as a treatment for both diabetes and obesity.
Semaglutide, one of the more well-known GLP-1s sold under the brand names Ozempic®, Wegovy®, and Rybelsus®, was originally developed to treat diabetes – but weight loss was a common side effect, and GLP-1s are now used for that purpose. In fact, the FDA has approved two GLP-1s, Saxenda® (liraglutide) and Wegovy, specifically for weight loss in people who are significantly over- weight and experiencing health complications.
So how do GLP-1s affect the risk of having a heart attack, stroke, or blood clot? It will be a few more years before we have long-term data, but there’s reason to believe that these medications do reduce the risk of heart disease – at least in some people.
GLP-1s have been studied the most in people with type 2 diabetes. A 2019 analysis of seven trials involving more than 50,000 patients found that taking these medications reduces the risk of a heart attack, stroke, or death due to heart disease by 12%. Although not an enormous decrease in risk, it’s certainly significant. Another studypublished in 2023 also found a 12% lower risk in patients with diabetes who didn’t have a history of heart failure, and a 15% reduction in those who had heart failure.
In fact, the American Heart Association (AHA) states that GLP-1s cause a “robust and consistent reduction” in heart attack and stroke risk in people with type 2 diabetes. The AHA now recommends that people with diabetes who are at a high risk for heart disease should take GLP-1s.
In people who don’t have diabetes, there’s less evidence to show the impact of these medications on heart disease risk. We don’t have results from large clinical trials yet, so we can’t be sure that GLP-1s will have the same effect on risk in people without diabetes compared to those who do have diabetes.
There is evidence that these medications reduce blood pressure and cholesterol in overweight people without diabetes, which would be expected to translate to a lower heart disease risk. But we’ll have to wait for theresults of larger studies to be sure.
It’s also not clear exactly how GLP-1s decrease the risk of heart attack and stroke. One likely possibility is that weight loss itself is the key. It’s well established that in people who are significantly overweight, even a small amount of weight loss can lower the risk of having a heart attack or stroke. Because these medications lead to weight loss, it’s not surprising that they would also reduce cardiovascular risk.
And yet, researchers believe that there’s more to the story. In addition to lowering blood pressure and cholesterol, GLP-1s also help to keep blood sugar under control, which reduces chronic inflammation and in turn reduces heart disease risk. There are ongoing studies to figureout exactly how these medications work and what mechanisms are at play.
It’s important to note that GLP-1s are not considered a good option for everyone. They should be used with caution in people with a history of arrhythmias (abnormal heart rhythms) since there’s some evidence that GLP-1s may exacerbate rhythm issues. These medications can also cause serious complications with the pancreas, thyroid, and kidneys – though these side effects are rare.
For now, it seems clear that GLP-1s can lower the risk of heart attack and stroke in people with type 2 diabetes, and there’s promising data that they may also reduce risk in people who don’t have diabetes. They’re not a magic bullet, though; the reduction in risk is relatively modest andthere’s a small risk of serious side effects. These medicines are also self- injected, and some people aren’t keen on giving themselves a shot. If you’re considering trying these new weight loss medications, it’s important to have an open conversation with your doctor about the potential risks and benefits.
*Originally published in The Beat — June 2023. Read the full newsletter here.