Serum IL-36 cytokines levels in type 2 diabetes mellitus patients and their association with obesity, insulin resistance, and inflammation

Background: The interleukin (IL)-36 cytokines include IL-36α, IL-36β, IL-36γ, and IL-36Ra. Little was known about their roles in type 2 diabetes mellitus (T2DM).

Methods: The study included 40 T2DM patients and 42 healthy control subjects. The anthropometric and biochemical measurements were performed using automatic biochemical analyzer, high-performance liquid chromatography, and electrochemiluminescence immunoassay. Circulating IL-36α, IL-36γ, IL-36Ra, and IL-17 levels were determined by enzyme-linked immunosorbent assay.

Results: Serum IL-36α, IL-36γ, and IL-17 levels in T2DM patients were significantly higher than those in controls, whereas serum IL-36Ra levels in T2DM patients were lower. Correlation analysis showed that serum IL-36α was positively correlated with high sensitivity C-reactive protein. Serum IL-36α was negatively correlated with IL-36Ra. Serum IL-17 was negatively correlated with low-density lipoprotein cholesterol.

Conclusions: This study demonstrated that T2DM patients displayed increased IL-36α and IL-36γ expression and decreased IL-36Ra expression. Moreover, the inflammatory cytokine levels were directly proportional to the inflammation and blood lipid levels. Our results suggest that IL-36 cytokines may be a new target for the diagnosis or treatment of T2DM.