Adults with type 1 diabetes (T1D) often face challenges with being overweight and obesity, increasing cardiovascular risk. A first randomized trial examined the effects of the dual GIP and GLP-1 receptor agonist tirzepatide on weight and metabolic parameters in adults with T1D. The 12-week trial, presented at EASD 2025, enrolled 24 participants (mean age 41 years, BMI 33.7 kg/m², HbA1c 7.3%) who received weekly subcutaneous tirzepatide or placebo.
Tirzepatide treatment reduced body weight by an average of 8.7 kg, with 82% of the loss attributed to fat mass while largely preserving fat-free mass. Total daily insulin dose decreased by 35% compared with placebo, with early reductions observed in pump users. HbA1c improved by 0.35%, and daily energy intake declined by 429 kcal. Physical activity levels remained unchanged.
No episodes of diabetic ketoacidosis or severe hypoglycemia occurred, and two participants withdrew for non-safety reasons. The trial demonstrates that tirzepatide produces rapid and meaningful metabolic improvements in adults with T1D, supporting further investigation in larger phase 3 studies to explore efficacy, safety, and underlying mechanisms.
Adults with type 1 diabetes (T1D) often face challenges with being overweight and obesity, increasing cardiovascular risk. A first randomized trial examined the effects of the dual GIP and GLP-1 receptor agonist tirzepatide on weight and metabolic parameters in adults with T1D. The 12-week trial, presented at EASD 2025, enrolled 24 participants (mean age 41 years, BMI 33.7 kg/m², HbA1c 7.3%) who received weekly subcutaneous tirzepatide or placebo.
Tirzepatide treatment reduced body weight by an average of 8.7 kg, with 82% of the loss attributed to fat mass while largely preserving fat-free mass. Total daily insulin dose decreased by 35% compared with placebo, with early reductions observed in pump users. HbA1c improved by 0.35%, and daily energy intake declined by 429 kcal. Physical activity levels remained unchanged.
No episodes of diabetic ketoacidosis or severe hypoglycemia occurred, and two participants withdrew for non-safety reasons. The trial demonstrates that tirzepatide produces rapid and meaningful metabolic improvements in adults with T1D, supporting further investigation in larger phase 3 studies to explore efficacy, safety, and underlying mechanisms.
