Effect of sitagliptin on serum levels of TNF-α, IL-1β and IL-10 in patients with type 2 diabetes mellitus

Type 2 diabetes mellitus (T2DM) is an inflammatory disease with alterations in immune system. Remarkably, cytokine imbalance plays an important role in pathogenesis of T2DM. The purpose of this study was to determine the serum levels of TNF-α, IL-1β and IL-10 and the effects of sitagliptin on the level of these cytokines in patients with T2DM.

Blood samples were collected from 60 T2DM patients and 30 healthy control subjects (HCs). T2DM patients were divided into two subgroups based on their treatment; with sitagliptin treatment (100 mg/day, n=30) for 8 months and without sitagliptin treatment (n=30). The serum levels of TNF-α, IL-1β and IL-10 cytokines were assessed using ELISA method. ANOVA with posthoc Bonferroni were applied to statistical analysis.

The serum level of TNF-α was significantly higher in T2DM patients without sitagliptin compared to HCs (p=0.002). Whereas, the serum level of TNF-α was significantly lower in patients with sitagliptin compared to patients without sitagliptin (p=0.01). The serum level of IL-10 showed a significant reduction in patients without sitagliptin compared to HCs (p=0.003). On the other hand, a significant elevation was observed in serum level of IL-10 between T2DM patients with and without sitagliptin (p=0.002). Considerably, no significant difference was observed in serum level of IL-1β between T2DM patients with and without sitagliptin and also in comparison to HCs.

Sitagliptin treatment significantly decreased the level of pro-inflammatory TNF-α and increased anti-inflammatory IL-10 in T2DM patients. It seems that sitagliptin had an anti-inflammatory effect on immune system of the patients.