Tirzepatide significantly lowers MACE, mortality, and HbA1c compared to semaglutide in real-world obesity and T2D patients

The global burden of obesity and type 2 diabetes (T2D) continues to rise, necessitating effective and safe long-term treatments. GLP-1 receptor agonists like semaglutide and dual GIP/GLP-1 receptor agonists like tirzepatide represent leading therapeutic options. While clinical trials have established their individual efficacy, real-world comparative data directly assessing their relative effectiveness and safety, particularly regarding cardiovascular outcomes and glycemic control, remains crucial for guiding clinical decisions and optimizing patient care.

Researchers conducted a retrospective propensity-matched cohort study using the TriNetX Research Network database. They identified 95,608 patients (mean age 75 years) aged >40 years or with obesity (BMI ≥ 30 kg/m2) and type 2 diabetes (HbA1c ≥ 6.5% or fasting glucose ≥ 125 mg/dL). Two cohorts were established: one initiating tirzepatide and another semaglutide, each with at least three prescriptions and no prior exposure to the comparator or other GLP-1RAs. A 1:1 propensity matching yielded 47,804 patients per cohort. Outcomes, including all-cause mortality, MACE (Major Adverse Cardiovascular Events), heart failure exacerbation, ischemic stroke/TIA, hospitalization/ED use, dementia, UTI, adverse GI effects, and changes in HbA1c, were assessed over a 1-year follow-up period.

Patients treated with tirzepatide demonstrated superior outcomes across several key metrics.

The tirzepatide cohort experienced a significantly lower incidence of MACE at 3.7% compared to 4.1% in the semaglutide group (Risk Ratio 0.918, 95% CI 0.862-0.978). All-cause mortality was also substantially lower with tirzepatide (0.2% vs. 0.4%; Risk Ratio 0.436, 95% CI 0.338-0.562). Furthermore, the tirzepatide group achieved better glycemic control, with a lower mean HbA1c (6.565% vs. 6.848%; p < 0.001) during the follow-up period. Adverse GI side effects were slightly less frequent in the tirzepatide cohort (9.8% vs. 10.2%; Risk Ratio 0.959, 95% CI 0.924-0.997). No significant differences were observed in heart failure exacerbation or UTI incidence between the two groups.