ObjectiveTo explore the effect of type 2 diabetes mellitus (T2DM) on the vascular endothelial function of patients with heart failure with mid-range ejection fraction (HFmrEF), and the impact of endothelial function damage on the long-term prognosis of HFmrEF. Metohds87 patients with T2DM and heart failure with mid-range ejection fraction (T2DM-HFmrEF), 98 patients with HFmrEF alone, and 70 healthy control who had been hospitalized at the department of cardiology of the First Affiliated Hospital of Xinjiang Medical University from December 2018 to January 2020 were included. The levels of serum TNF-α, IL-6, vWF, eNOs and E-selectin were determined by enzyme-linked immunosorbent assay. The oxidative stress and vascular endothelial function related indicators of the 3 groups were analyzed. The primary endpoint (all-cause death, exacerbation of heart failure and rehospitalization, or exacerbation of heart failure) and secondary endpoint events (non-fatal myocardial infarction, stable and unstable angina pectoris, or stroke) were followed up for 1 year after discharge.ResultsThe levels of TNF-α, IL-6, vWF, and E-selectin in the HFmrEF combined with diabetes group were higher than those in the HFmrEF without diabetes group (P<0.05). Multivariate Cox regression analysis showed that BNP (HR=1.001, P=0.036), eNOs (HR=1.04, P<0.001), and IL-6 (HR=1.002, P<0.001) were related to the primary end point of all patients with HFmrEF. Glycated hemoglobin (HR=1.37, P=0.046), E-selectin (HR=1.01, P=0.003), vWF (HR=1.02, P=0.017), and IL-6 (HR=1.006, P=0.005) were related to the secondary end point of all patients with HFmrEF. The results of subgroup analyze showed that E-selectin (HR=1.014, P=0.012) and IL-6 (HR=1.008, P=0.007) were related to the secondary endpoint events in the HFmrEF combined with diabetes group, but were not related to the secondary end point events of the non-diabetic group (P>0.05).ConclusionsOxidative stress and vascular endothelial function damage may be involved in the pathogenesis of T2DM-HFmrEF. Serum IL-6 and E-selectin levels are related to the endpoint events in T2DM-HFmrEF patients.