Dipeptidyl-peptidase-4 inhibitors have anti-inflammatory effects in patients with type 2 diabetes

Aims Systematic low-grade inflammation is considered to be an important factor leading to the development of T2DM and the progression of its complications. Dipeptidyl-peptidase-4 (DPP-4) inhibitors show potential anti-inflammatory effects in patients with T2DM. This meta-analysis aimed to evaluate the anti-inflammatory effects of DPP-4 inhibitors in patients with T2DM. Methods A comprehensive search was performed in PubMed, Web of Science, Embase, and Cochrane Central Register of Controlled Trials to identify randomized controlled trials that assess the anti-inflammatory effects of DPP-4 inhibitors. Quantitative data analysis was conducted by a random-effects model. Sensitivity analyses were conducted to determine the robustness of the pooled results. Results Twenty-two studies with 1595 patients with T2DM were included. Pooled results showed that DPP-4 inhibitor therapy was significantly associated with the reduction of C-reactive protein (CRP) (SMD, − 0.56, p < 0.01), TNF-α (SMD, − 1.69, p < 0.01), IL-6 (SMD, − 0.67, p < 0.01), and IL-1β (WMD, − 8.21 pg/ml, p < 0.01). Leave-one-out meta-analysis showed no significant change in the pooled results of CRP and TNF-α. Conclusion This meta-analysis demonstrated that DPP-4 inhibitors can significantly attenuate low-grade inflammatory state in patients with T2DM. In addition to improving glycemic control, DDP-4 inhibitors might offer extra therapeutic value by controlling inflammation. Graphical Abstract