Tirzepatide proves safety, efficacy in T1D in real world

The use of tirzepatide in a real-world setting demonstrates a favourable safety profile and results in weight loss, lower insulin requirements, and better glycaemic measurements among patients with type 1 diabetes (T1D), as shown in a study presented at EASD 2025.

“In real-world use in people with T1D, tirzepatide was safe and generally well tolerated, with significant clinical benefits including weight loss, reduced insulin requirements, and improvement of blood sugar metrics, without increasing hypoglycaemia,” said lead author Dr Simon Berry, Division of Clinical Medicine, University of Sheffield, Sheffield, UK.

Berry and his team conducted this longitudinal, retrospective study in 57 people with T1D (66.7 percent female) who initiated tirzepatide at a large tertiary centre. They reviewed case notes for current dose, side effects, clinic weights, and hospital attendances and obtained glycaemic metrics from the respective continuous glucose monitoring cloud applications.

Paired data were excluded from the analysis in case of missing data. Variables measured before and after 6 months of tirzepatide treatment were compared using two-tailed paired t-tests. The authors then presented the data as median and mean. They also used Pearson’s rank test to analyse for correlations.

Before tirzepatide use, the median age was 39 years, weight 101.6 kg, BMI 36.3 kg/m², and HbA1c 60 mmol/mol. The dose of tirzepatide at 6 months was 2.5 mg once weekly in nine participants (18 percent), 5 mg in 37 (74 percent), 7.5 mg in two, and 10 and 15 mg in one individual each. [EASD 2025, abstract 825]

After 6 months of tirzepatide use, mean weight substantially decreased by 9.8 kg (9.3 percent, 95 percent confidence interval [CI], 7.7‒11.9; p<0.001) in 42 participants.

Mean total daily insulin dose also decreased by 25.2 percent from 74.4 units to 57.3 units (95 percent CI, 8.2‒26.1; p<0.001; n=27), with a mean reduction of 11 units (95 percent CI, 4.5‒17.5; p=0.002; n=26) in total daily bolus dose and 10.8 units (95 percent CI, 4.5‒17.1; p=0.001; n=39) in basal dose. Finally, mean HbA1c showed a 3.7-mmol/mol reduction (95 percent CI, 1.0‒6.4; p=0.008; n=33).

Glucose management

Furthermore, percentage weight change did not exhibit a significant relationship with increase in time in range (r, ‒0.218; p=0.239; n=31). There was also no improvement seen in the glucose management indicator (r, 0.099; p=0.597).

In terms of safety, 21 participants (36.8 percent) reported experiencing side effects. The most common adverse events (AEs) were nausea or vomiting (26.3 percent) and abdominal pain (14.0 percent). However, 50 participants (87.7 percent) continued using tirzepatide at 6 months despite these AEs.

Notably, three patients had an unplanned hospital admission (median length of stay 1 day) due to abdominal pain. One of them was found to have gallstones. No cases of pancreatitis were recorded.

“Definitive data from randomized controlled trials (RCTs) in T1D are required to confirm these findings,” Berry said.

According to Dr Ahmed Iqbal, senior author and senior clinical lecturer at the University of Sheffield and Sheffield Teaching Hospitals, Sheffield, UK, he and his team are “very keen” for RCTs to be performed to validate the current findings.

“Despite the paucity of RCT evidence, off-label prescription of GLP-1 agonists such as semaglutide and GLP-1/GIP dual agonists such as tirzepatide in T1D is increasingly prevalent, making this a pressing issue,” Iqbal said.

“One patient group that we think require particular attention in future research studies is young adults (aged 16‒25 years) living with T1D and obesity, in which the reduction of cumulative risk over a longer period of time could lead to greater long-term benefits,” he added.