People with type 2 diabetes and obesity may benefit from treatment with tirzepatide. Tirzepatide, marketed under the brand name Mounjaro, can reduce the risk of heart attacks and hospitalizations due to infections by about one-third each compared with a conventional diabetes medication. Researchers at the Technical University of Munich (TUM) and Harvard Medical School demonstrated this using health insurance data.
In brief
- Database study examines protective effects of GLP-1 receptor agonist tirzepatide
- Reduced risk of serious events such as heart attacks
- Risk of hospitalization due to infections reduced by one-third
For their study, published in The BMJ, the researchers analyzed a large dataset from U.S. health insurance providers. They compared patients treated with tirzepatide versus patients treated with sitagliptin, a diabetes medication considered neutral with respect to cardiovascular outcomes.
The results revealed clear advantages of the GLP-1 drug, which has also attracted widespread public attention in recent years as a weight-loss treatment. After one year, 4.4 percent of patients treated with the comparator drug had experienced a heart attack or stroke or had died. In the tirzepatide group, the rate was just 2.9 percent. This corresponds to a reduction in relative risk of about one-third.
Reduced hospitalizations due to infections
In addition, significantly fewer patients treated with tirzepatide had infections requiring hospital admission: the associated risk was reduced by 36 percent. The risk of infection-related death was reduced by as much as 60 percent.
"The data on infections surprised us because the findings were so striking," says Dr. Nils Krüger, first author of the study and a resident physician in the Department of Cardiovascular Diseases at TUM University Hospital. "Previous studies have suggested that people treated with GLP-1 agonists are less likely to be hospitalized for infections and less likely to die from them." According to Krüger, the reasons for this association are not yet fully understood. "There is evidence that obesity promotes inflammatory processes in the body, which may in turn impair immune function. The exact mechanisms and whether this apparent benefit would also occur without weight loss now need to be investigated."
Studies based on routine clinical data complement traditional clinical trials
In Krüger's view, studies that use routine clinical data to compare the effects of medications are an important complement to traditional clinical trials. This is especially true for GLP-1 agonists such as tirzepatide and semaglutide (Mounjaro, Wegovy and Ozempic). Because these drugs have only been on the market for a relatively short time, there are only few large-scale studies examining the full range of effects associated with this class of medications. This is why more studies such as the study published in The BMJ are what medical societies and regulatory authorities need as a basis for their recommendations.
"Clinical trials are increasingly comparing active ingredients with one another," says Krüger. Regulatory authorities, however, often also require comparisons against the established standard of care rather than against another modern drug. "Database studies that are benchmarked against the results of traditional clinical trials can fill this gap without actually withholding potentially beneficial therapies such as GLP-1 agonists from study participants," he says. By enabling comparisons with standard diabetes treatment, Krüger hopes the study will provide an additional tool to support decision-making by patients and their physicians.
N. Krüger, S. Schneeweiss, S. Wang. "Tirzepatide and the risk of atherosclerotic cardiovascular events: population based cohort study" . The BMJ (2026). DOI: 10.1136/bmj-2026‑100011
