LAS VEGAS — Off-label use of GLP-1 drugs by people with type 1 diabetes (T1D) did not lead to diabetic ketoacidosis (DKA) or pancreatitis in a large 1-year single-center study.
Moreover, GLP-1 agonist use in people with T1D was associated with lower overall rates of hospitalization, as has occurred in type 2 diabetes, endocrinology fellow Justin Do, DO, of Loma Linda University Medical Center, California, reported here at the American Association of Clinical Endocrinology (AACE) Annual Meeting 2026.
“I think GLP-1s can help a lot of our patients with T1D, with the cardiovascular benefits, the renal benefits, and a lower hospitalization rate…However, further studies are warranted in this population,” Do told Medscape Medical News.
Obesity has risen among people with T1D over the last decade, and is now estimated at about 37% in the US. Although GLP-1 agonists are not approved by the FDA for T1D management, off-label adjunctive use has risen for those with obesity. This has raised concerns and anecdotal reports of DKA due to excessive insulin dose reduction and reduced food consumption, Do said.
Study Details
The retrospective, cross-sectional study included a total of 7377 adults with T1D seen in the Loma Linda University Medical Center between July 1, 2024, and July 1, 2025. Of those, 255 were using a GLP-1 medication and 7122 were not. The GLP-1 users were older than the nonusers (mean age of 45 vs 37 years), had a higher proportion of females (65.2% vs 50.3%), and had higher BMIs (33.4 vs 26.6).
Semaglutide was the most commonly-used GLP-1 (65.5% of GLP-1 users) followed by tirzepatide (23.5%). The rest were using the older-generation drugs: liraglutide or dulaglutide.
Based on ICD-10 coding, there were no admissions for DKA or pancreatitis among the GLP-1 users, while those rates among nonusers were 0.39% and 0.55%. Those differences were not statistically significant, at P = .62 and P = .64, respectively.
Of note, the GLP-1 users had a significantly lower overall incidence of hospital admission (7.45% vs 13.11%; P = .01).
Do told Medscape that this was an incidental finding and he didn’t examine the reasons for admission, “but I assume it’s mostly cardiovascular.” He noted that this is something for future studies to look at it.
Need to Individualize Insulin Dose Adjustments
Asked to comment, session moderator Viral N. Shah, MD, professor of medicine and director of diabetes clinical research at the Center for Diabetes and Metabolic Diseases, Indiana University School of Medicine, Indianapolis, told Medscape Medical News, “It’s reassuring…but the limitation of observational, single-center, retrospective chart review is that there are selection biases. You are prescribing to people who are likely to do better.”
He said that Eli Lilly’s two large ongoing randomized clinical trials of tirzepatide in T1D, SURPASS-T1D-1 and SURPASS-T1D-2 should provide more solid data.
“ I think they will tell us whether the observation that we are seeing will turn out to be true, or whether there may be some differences,” he said. “But overall, I’m optimistic that these molecules are safe in people with T1D, and we haven’t seen any safety signals.”
Shah, who previously conducted a small randomized trial of tirzepatide in people with T1D, also with zero cases of DKA, said it’s important to individualize insulin dose adjustment in patients with T1D when initiating them on a GLP-1. The dose needs to be reduced to prevent hypoglycemia, particularly if they’re eating less, but can’t be lowered so much that they develop DKA, he explained.
For example, in an individual with a baseline A1c less than 7.5% and time in range 65-70%, “I would reduce the insulin by about 20% to 30%, even at the lowest (GLP-1) dose. “Close follow-up during this time is key,” he said.
Do has no disclosures. Shah’s institute has received research funding from Lilly, Enable Bioscience, Zucara Therapeutics, Cystic Fibrosis foundation, and Breakthrough T1D. He personally has received honoraria from Sanofi, Novo Nordisk, Lilly, Dexcom, Insulet, Tandem Diabetes Care, Medtronic, Sequel Med Tech, Abbott Diabetes, Roche, Biomea Fusion, and T1D Scout for advising, consulting, and/or speaking.
Miriam E. Tucker is a freelance journalist based in the Washington DC area. She is a regular contributor to Medscape, with other work appearing in The Washington Post, NPR’s Shots blog, and Diatribe. She is on X (formerly Twitter) @MiriamETucker and BlueSky @miriametucker.bsky.social
