Relative Effectiveness and Safety of the GLP-1 (Glucagon-Like Peptide 1) Receptor Agonists, Semaglutide and Liraglutide in the Treatment of Obese Type 2 Diabetics: A Prospective Observational Cohort Study in Poland.

PURPOSE: To compare the efficacy and safety of semaglutide and liraglutide over one year in obese Polish patients with type 2 diabetes. PATIENTS AND METHODS: In this prospective, observational cohort study conducted in Poland in 2024, 460 patients aged 18-80 were enrolled: 333 received semaglutide (Group 1), and 133 received liraglutide (Group 2). RESULTS: After 12 months, HbA1c levels significantly decreased in both groups: Group 1: from 6.09 ± 1.14% to 5.42 ± 0.82% (mean decrease: 0.67 ± 0.37%,<0.0001). Group 2: from 5.78 ± 0.75% to 5.17 ± 0.54% (mean decrease: 0.61 ± 0.28%,<0.001). BMI decreased by 5.36 ± 3.45 kg/m² in Group 1 and 4.41 ± 4.63 kg/m² in Group 2 (<0.0001), with greater reduction in Group 1 (=0.017). Gastrointestinal adverse effects were most common, including nausea, vomiting, constipation, gastritis, and diarrhea, with higher incidence in Group 1. HbA1c reduction correlated with baseline HbA1c, age, and gender; BMI reduction correlated with baseline HbA1c and BMI. CONCLUSION: Semaglutide was more effective than liraglutide in reducing HbA1c and BMI. Gastrointestinal symptoms were the most frequent side effects in both groups.