Effect of the Use of DPP4 Inhibitors Alone or Combined with SGLT2 Inhibitors on HbA1c, Apolipoproteins and Renal Function of Children, Adolescents and Young People with DM1: A Cohort Study

Background/Objectives: Type 1 diabetes mellitus (T1DM) is a chronic autoimmune condition often managed exclusively with insulin. However, the search for adjuvant therapies has gained attention, including dipeptidyl peptidase-4 inhibitors (DPP4i) and sodium-glucose cotransporter 2 inhibitors (SGLT2i), despite limited evidence in pediatric populations. To evaluate the impact of DPP4i, alone or combined with SGLT2i, on glycemic control (HbA1c), lipid profile (ApoB and ApoA-I), and renal function (eGFR and albuminuria) in children, adolescents, and young adults with T1DM, this study was conducted. Methods: This cohort study analyzed data from 76 patients with T1DM aged under 25, followed for 4 to 20 months. Patients were grouped based on exposure to DPP4i alone, DPP4i + SGLT2i, or no additional therapy. Glycemic, lipid, and renal parameters were assessed at baseline and follow-up. Results: A significant reduction in HbA1c was observed in the overall sample (p < 0.001), regardless of treatment group, suggesting a positive effect of interdisciplinary care. There were no statistically significant differences in HbA1c variation among the groups. ApoB decreased significantly over time (p < 0.001), and ApoA-I levels were initially higher in the DPP4i + SGLT2i group. A significant reduction in albuminuria was identified in the DPP4i-only group compared to controls (p = 0.029), indicating a potential renoprotective effect. No significant changes in eGFR were observed. The use of DPP4i, with or without SGLT2i, was not associated with significant improvements in glycemic or lipid outcomes compared to standard therapy. However, DPP4i monotherapy was associated with a reduction in albuminuria, suggesting a possible benefit for renal protection. Conclusions: These findings highlight the need for larger, randomized studies to confirm the therapeutic role of these agents in young individuals with T1DM.