Study on the relationship of IL-12 and IL-4 levels with macroangiopathy in type 2 diabetes mellitus

Objective: To study the relationship of interleukin-12 (IL-12) and IL-4 levels with macroangiopathy in type 2 diabetes mellitus by comparing the serum IL-12 and IL-4 levels and intima-media thickness (IMT) between the healthy controls and the type 2 diabetic patients with or without macroangiopathy. Methods: 30 healthy controls and 120 cases with type 2 diabetes mellitus from November 2011 to November 2012 were selected. In accordance with the carotid intima-media thickness, the type 2 diabetes mellitus patients were divided into group A with IMT below 1.0 mm, group B with IMT between 1.0 mm and 1.2 mm, group C with IMT between 1.2 mm and 1.4 mm, group D with IMT over 1.4 mm. ELISA was used to measure the levels of serum IL-12 and IL-4 in all groups. And the measurement results of serum IL-12 and IL-4 levels in the groups were compared. Results: Type 2 diabetes mellitus groups had significantly higher serum IL-12 levels and much lower IL-4 levels than the healthy control group. In the type 2 diabetes mellitus groups, the thicker the IMT was, the higher the incidence of complications became. IL-12 level was positively correlated with IMT while the IL-4 level was negatively correlated with IMT. Conclusions: IL-12 levels in patients with type 2 diabetes were significantly higher and IL-4 levels were significantly lower than those in the healthy people. In patients with type 2 diabetes, the IL-12 levels increased while the IL-4 levels gradually declined with the advance of macroangiopathy.