Retrospective Comparative Study of Oral Versus Subcutaneous Semaglutide in Patients with Type 2 Diabetes Mellitus

Semaglutide represents a unique therapeutic option for patients with type 2 diabetes mellitus (T2DM), being the first and currently only glucagon-like peptide-1 receptor agonist (GLP-1RA) available in both subcutaneous and oral formulations. This study aimed to compare the effectiveness of oral versus subcutaneous (sc) semaglutide on metabolic parameters and cardiovascular risk factors in T2DM patients. This is a retrospective real-world study including adult patients with T2DM taking oral or sc semaglutide followed at the ASUGI Diabetes Center. We analyzed data from 434 patients (median age 70 years, diabetes duration 13 years), treated with oral (n = 232) or sc (n = 202) semaglutide. The oral formulation had a higher discontinuation rate. Among these patients, 130 patients in the oral group and 145 in the sc group had an 18-month follow-up. When comparing these groups, patients taking sc semaglutide had a significantly higher baseline BMI. However, multivariate linear regression models suggested that both formulations were comparably effective in reducing HbA1c and BMI, with baseline values being the primary predictors of response. To address BMI imbalances, propensity score matching was performed, identifying 55 matched pairs. Both oral and sc semaglutide reduced HbA1c and BMI and there were no significant differences in the median change in HbA1c and BMI between groups. Interestingly, oral semaglutide was associated with a significantly greater reduction in diastolic blood pressure compared to the sc formulation. Furthermore, concomitant therapy with SGLT2 inhibitors significantly enhanced the reduction in total and LDL cholesterol. Oral and subcutaneous semaglutide show comparable effectiveness in lowering HbA1c and BMI in a real-world setting.