Title: Inflammatory And Autoimmune Biomarkers With Chronic Sitagliptin Plus Metformin Users In Type 2 Diabetes Mellitus
Authors: Rasha Kareem sachet, Jubran Khaleel Hassan, : Dheyaa Kadhim Al-Waeli , Falah Hassan Shari
Volume: 10
Issue: 7
Pages: 66-70
Publication Date: 2026/07/28
Abstract:
Background: Type 2 diabetes mellitus (T2DM) is characterised by chronic low-grade inflammation and immune dysregulation. Immunomodulatory effects of dipeptidyl peptidase-4 (DPP-4) inhibitors, such as sitagliptin, have been demonstrated, but the long-term relationship of these effects with inflammatory and autoimmune biomarkers is not well understood. In the current study, we studied the serum high-sensitivity C-reactive protein (hs-CRP) and antinuclear antibodies (ANA) in the patients with T2DM under chronic therapy with sitagliptin plus metformin. Methods: This prospective case-control study involved 85 subjects, including healthy controls (n = 30), patients with T2DM on chronic sitagliptin and metformin therapy (n = 25), and patients with T2DM on other antidiabetic medications (n = 30). Serum hs-CRP and ANA levels were determined using enzyme-linked immunosorbent assay (ELISA). Data analysis was performed using the Kruskal-Wallis test followed by the Mann-Whitney U test for pairwise comparison. Cohen's f was used to estimate effect sizes, and statistical significance was P < 0.05. Results: There were significant differences between the study groups in the serum levels of hs-CRP and ANA (P = 0.0001 and P = 0.0219, respectively). The highest hs-CRP concentrations were observed in patients on chronic sitagliptin plus metformin therapy, followed by patients on other antidiabetic medications, and the lowest levels were seen in healthy controls. Similarly, ANA levels were significantly higher in the sitagliptin plus metformin group than in either of the two comparison groups. The effect size observed was large for hs-CRP (Cohen's f = 0.7) and moderate for the ANA (Cohen's f = 0.3). Conclusions: Long-term treatment with sitagliptin plus metformin was associated with higher circulating levels of hs-CRP and ANA than in healthy controls and patients receiving other antidiabetic therapies. These results are in favour of ongoing inflammation and immune system changes in patients with T2DM and stress the need for larger prospective studies to elucidate the mechanisms underlying these associations and their possible clinical implications.