GLP-1 Studies Suggest Benefits Extend to Infectious Diseases

Recent studies suggest that people with type 2 diabetes on GLP-1 receptor agonists were less likely to develop tuberculosis (TB) or be hospitalized or die from infections.

In an international study of more than 7 million people, type 2 diabetes patients taking a GLP-1 drug were less likely to develop TB compared with those on other antidiabetic medications, including DPP-4 inhibitors (HR 0.49, 95% CI 0.43-0.56), sulfonylureas (HR 0.53, 95% CI 0.47-0.59), metformin (HR 0.60, 95% CI 0.51-0.70), and SGLT2 inhibitors (HR 0.82, 95% CI 0.72-0.92).

“These findings suggest that beyond their established metabolic benefits, GLP-1 receptor agonists may confer additional advantages in lowering infection risk,” Chih-Cheng Lai, MD, of Chi Mei Medical Center in Taiwan, and colleagues concluded in Nature Communications.

And in a real-world study that backed the major adverse cardiovascular events (MACE) benefit for tirzepatide (Mounjaro, Zepbound), the GLP-1 drug was also linked with protection against serious infections.

Published in The BMJ, the cohort study of over 50,000 U.S. adults with type 2 diabetes and atherosclerotic cardiovascular disease found that tirzepatide was associated with substantially lower 1-year risks for various infection outcomes compared with sitagliptin (Janumet), a DPP-4 inhibitor:

• Infection-related mortality: HR 0.40 (95% CI 0.26-0.61)
• Infection-related hospitalization: HR 0.64 (95% CI 0.55-0.75)
• Urinary tract infections: HR 0.83 (95% CI 0.76-0.91)
• Infections in any care setting: HR 0.83 (95% CI 0.78-0.87)

A reduction in all-cause mortality among the tirzepatide users was also observed in the study from researchers led by Nils Krüger, MD, of Harvard Medical School in Boston.

“One plausible explanation that our study supports is the substantial reduction in serious bacterial infections observed among individuals who initiated tirzepatide, suggesting that part of the survival benefit may reflect effects beyond atherosclerotic mechanisms,” wrote Krüger and colleagues.

Together, the two studies lend support to a recent umbrella review that turned up convincing evidence that GLP-1 medications had protective associations against infection-related outcomes, especially for serious infections.

People with diabetes have an increased risk for active TB and worse subsequent outcomes, according to the CDC. And past research has suggested that obesity may be responsible for 1 in 10 infection-related deaths in adults. Obesity’s ties to increased systemic inflammation, immune system dysfunction, and metabolic disturbances likely help drive that association.

Based on preclinical and translational data, Lai and co-authors suggested that GLP-1 drugs could influence people’s susceptibility to infections and outperform other classes of antidiabetics at lower infection risk.

“In obese, high-fat diet-induced diabetic mice, GLP-1RA [receptor agonists] outperformed insulin in restoring host defense against infection by enhancing neutrophil phagocytosis, migration, and bacterial clearance,” they wrote.

“Prolonged GLP-1RA treatment further improved infection resistance by correcting hyperglycemia, increasing neutrophil counts, and restoring innate immune competence,” added Lai and colleagues. “These improvements indicate that GLP-1RA may provide a superior anti-infective effect compared with conventional therapy, not only through glycemic control but also by directly enhancing immune cell function.”

Beyond their long-proven benefits for type 2 diabetes and obesity, GLP-1 drugs such as tirzepatide and semaglutide (Ozempic, Wegovy) have garnered a growing number of FDA-approved indications for conditions including chronic kidney disease, sleep apnea, and metabolic dysfunction-associated steatohepatitis, and to reduce the risk for MACE.

And observational and small randomized studies have suggested other potential benefits as well, including cancer risk or recurrence reduction and for people with addictions to alcohol or opioids.

Study Details

For the TB study, the investigators drew on 2017 to 2025 data from the TriNetX international health research network. After adjustment, baseline characteristics — such as age, sex, race, HbA1c, body mass index, and comorbidities — were well balanced within each cohort, which were divided up by antidiabetic medication class.

Limitations included a lack of data on key clinically relevant TB variables, limiting analysis of GLP-1 receptor agonists effects across TB exposure patterns and disease phenotypes. In addition, substantial variation in TB epidemiology across countries could have introduced geographical confounding.

In the MACE study, the researchers analyzed data from two U.S. administrative claims databases from 2022 to 2025 on adults 40 and over with type 2 diabetes and atherosclerotic cardiovascular disease. Median patient age was 70 years, 51% were women, and 85% took statins. Limitations included the relatively short follow-up period, which could underestimate long-term cardiovascular and safety effects.