Insulin resistance, blood glucose and inflammatory cytokine levels are risk factors for cardiovascular events in diabetic patients complicated with coronary heart disease

This study was designed to investigate the relation of insulin resistance, blood glucose and inflammatory cytokines with cardiovascular events in diabetic patients complicated with coronary heart disease (CHD). A total of 120 patients with diabetes mellitus type 2 (T2DM) complicated with CHD admitted to Jinan Central Hospital from January 2015 to March 2016 were enrolled in this study. There were 60 cases complicated with cardiovascular events and 60 had no history of cardiovascular events; there were 40 cases with abnormal blood glucose, 40 with insulin resistance and 40 with elevated inflammatory cytokines. Changes in the levels of blood glucose, fasting serum insulin and inflammatory cytokines as well as changes in the homeostasis model assessment of insulin resistance indexes (HOMA-IR) were recorded and compared among groups of patients. Besides, changes in the Global Registry of Acute Coronary Events (GRACE) risk score and the incidence rate of cardiovascular events were also detected and multivariate logistic regression analysis was conducted so as to identify relevant risk factors. Our results showed the fasting blood glucose and the 2 h postprandial blood glucose levels in the non-cardiovascular event group were lower than those in the cardiovascular event group (P<0.05). However, levels of fasting serum insulin and HOMA-IR in the non-cardiovascular event group were significantly higher than those in the cardiovascular event group (P<0.05). Additionally, levels of tumor necrosis factor-α (TNF-α), interleukin-6 and C-reactive protein in the non-cardiovascular event group were significantly lower than those in the cardiovascular event group (P<0.05). Moreover, GRACE risk scores in patients with elevated inflammatory cytokines were higher than those in patients with insulin resistance and those in patients with blood glucose abnormalities (P<0.05). The incidence rate of cardiovascular events in patients with blood glucose abnormalities was lower than that in patients with insulin resistance and that in patients with elevated inflammatory cytokines. There was a positive correlation between TNF-α and HOMA-IR (P<0.05), and between HOMA-IR and the GRACE risk score (P<0.05). Blood glucose abnormalities, insulin resistance and inflammatory cytokines were all independent risk factors for cardiovascular events. Based on our findings, stronger inflammatory responses in patients with T2DM complicated with CHD lead to higher incidence rates of cardiovascular events. Besides that, elevated blood glucose and insulin resistance levels are also independent risk factors for cardiovascular events.