EASD 2025: Tirzepatide leads to significant fat loss, insulin dose reduction in T1DM

In this first controlled trial of tirzepatide (TZP) in T1DM, results suggest meaningful metabolic benefits, including substantial fat loss and insulin dose reduction without compromising safety. These findings, shared at the 61^st European Association for the Study of Diabetes (EASD) Annual Meeting, support further investigation of TZP as a potential adjunct therapy in T1DM management, particularly for patients with obesity.

Study details: In the 12-week, double-blind TIRTLE1 trial, 24 adults with T1DM, obesity (BMI >30), and disease duration >2 years were randomized to weekly SC TZP or placebo. Primary endpoint: change in body weight; secondary endpoints: insulin dose, HbA1c, dietary intake, and body composition.

Results: TZP led to a significant mean weight reduction of 8.7 kg (8.8%; 95% confidence interval [CI], -12.0 to -5.5 kg; p<0.0001), with 82% of the loss attributed to fat mass (mean difference -7.2 kg; 95% CI, -10.5 to -3.9 kg; p=0.0002). Insulin requirements dropped by 35.1% compared with placebo (95% CI, -46.5 to -21.3%; p=0.0002), with early reductions seen in pump users. HbA1c decreased modestly (mean difference, -0.35%; 95% CI, -0.7 to 0.0%; p=0.05). No severe hypoglycemia or DKA was reported.

Source:

Snaith, J.R., et al. Tirzepatide reduces weight and insulin dose and improves body composition in type 1 diabetes: a 12-week, randomised, double-blind, placebo-controlled trial (TIRTLE1). Abstract #75. Presented at 61^st EASD Annual Meeting of the European Association for the Study of Diabetes. https://link.springer.com/article/10.1007/s00125-025-06497-1