Abstract
The purpose of this study was to explore the correlation of insulin resistance (IR) and leptin with inflammatory factors and vascular endothelial injury in patients with type 2 diabetes mellitus (T2DM) complicated with coronary heart disease (CHD) was explored. One hundred and fifty normal patients (normal group), 150 patients with pure T2DM (T2DM group) and 150 patients with T2DM complicated with coronary heart disease (T2DM + CHD group) were selected from Xi'an No. 5 Hospital. All the participants met our inclusion criteria. Age, body mass index, waist-to-hip ratio, blood lipid and fasting plasma glucose (FPG), of all the subjects were measured. Chemiluminescent immunoassay was adopted for the detection of FPG and double-antibody sandwich method was used for the determination of fasting plasma leptin, and assay of high-sensitivity C-reactive protein (hs-CRP), interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α). Insulin resistance index (IRI) was used to evaluate IR and enzyme-linked immunosorbent assay was adopted for the detection of von Willebrand factor (vWF) and endothelin (ET-1). Compared with the control group, patients in the T2DM + CHD group and those in the T2DM group had higher homeostasis model assessment-IR, and higher assay of plasma leptin, hs-CRP, IL-6 and TNF-α (P<0.05), and lower vascular endothelial function (P<0.05). Moreover, compared with the T2DM group, T2DM + CHD group had higher plasma leptin, and higher assay of hs-CRP, IL-6 and TNF-α (P<0.05). IRI was positively correlated with hs-CRP (r=0.521, P=0.001), IL-6 (r=0.359, P=0.001) and TNF-α (r=0.386, P=0.001), leptin was positively correlated with hs-CRP (r=0.305, P=0.001), IL-6 (r=0.259, P=0.002) and TNF-α (r=0.429, P=0.001), and IRI had no correlation with ET-1 (r=0.058, P=0.734) and vWF (r=0.047, P=0.812), that is, it had no direct correlation with vascular endothelial function. Level of leptin was positively correlated with ET-1 (r=0.366, P=0.001) and vWF (r=0.471, P=0.001), that is, it was negatively correlated with vascular endothelial function. Our results showed that leptin, hs-CRP, IL-6 and TNF-α are involved in the occurrence and development of CHD in patients with T2DM. IR has no direct correlation with the occurrence and development of CHD in patients with T2DM.