Real‐world effectiveness and safety of tirzepatide in type 1 diabetes and obesity: Impact on glycaemia, weight, and cardiometabolic risk markers

Aims

To evaluate the effectiveness and safety of tirzepatide on glycaemia, weight, and markers of cardiometabolic risk in people with type 1 diabetes and obesity.

Materials and Methods

This retrospective cohort study compared 142 adults with type 1 diabetes (BMI ≥ 30 kg/m2) initiated on tirzepatide against 50 age-, sex- and BMI-matched controls. Outcomes included changes in HbA1c, weight, total daily dose of insulin, cardiometabolic markers, and safety data including hospitalisations over 12 months.

Results

Participants (mean age 42.8 years, BMI 37.4 kg/m2, HbA1c 64.3 mmol/mol, 32% male) were followed up for a median of 365 days. The median tirzepatide dose (72.4%) was 5 mg weekly. Compared to controls, the tirzepatide group achieved significant mean reductions in: HbA1c (6.5 mmol/mol [95% CI 3.8–9.1], p < 0.001) (0.6% [0.4–0.8]), weight (13.4 kg [11.0, 15.8], p < 0.001) and total daily insulin dose (29.9 units [16.9, 42.9], p < 0.001). Significant improvements were observed in systolic blood pressure (12.6 mmHg, p < 0.001), diastolic blood pressure (4.1 mmHg, p = 0.034), total cholesterol (0.8 mmol/L, p < 0.001), non-HDL cholesterol (0.6 mmol/L, p < 0.001) and triglycerides (0.7 mmol/L, p < 0.001) compared to controls. While side effects were common, 89.4% continued on tirzepatide at 1 year. There was no between-group difference in severe hypoglycaemia, ketoacidosis nor hospitalisation rates.

Conclusions

In a real-world setting, tirzepatide significantly improves glycaemia, weight, and markers of cardiometabolic risk in people with type 1 diabetes and obesity with a reassuring safety profile. These findings warrant large-scale RCTs to evaluate long-term cardiovascular outcomes in this high-risk population.