No abstract

Background: Diabetes-induced endothelial dysfunction is a critical and initiating factor in the genesis of diabetic vascular complications. Omentin exerts direct influence on glucose metabolic disorders and vascular dysfunction. But the association between omentin and cardiovascular events reported by recent studies are paradoxical. Thus, we intend to investigate the relationship between omentin and vascular function in patients with different glucose metabolism states.Methods: A total of 162 elderly patients were stratified into three groups by the status of glucose tolerance test [normal glucose tolerance (NGT), impaired glucose regulation (IGR), type 2 diabetes mellitus (T2DM)]. All participants underwent complete clinical work-up. Fasting blood samples were collected for biochemical measurement. Circulating omentin, adiponectin, interleukin-6 (IL-6) and tumor necrosis factor α (TNF-α) levels were detected by enzyme-linked immunosorbent assays. Endothelial and vascular smooth muscle function were evaluated by flow-mediated dilatation (FMD) and nitrate-mediated dilation test (NMD) respectively.Results: Circulating omentin levels were lower in IGR group compared with NGT and were lowest in individuals with T2DM group (P=0.004). FMD has a significant and negative association with systolic blood pressure (SBP), glycosylated hemoglobin (HbA1c), fasting plasma glucose (FPG), fasting insulin and interleukin-6 (IL-6), while have a positive relationship with log (omentin) by bivariate correlation analysis in all subjects. After adjusting for traditional cardiovascular factors, log (omentin) was independent related factor that influenced FMD (β=-0.346，P=0.01) in IGR subjects, but not in the subgroups NGT and T2DM.Conclusions: A decreased omentin levels had been suggested to be a biomarker of glucose metabolic disorders and potentially cardiovascular risk. Higher circulating omentin level are independent determining factors for endothelial dysfunction in impaired glucose regulation (IGR) subjects suggesting and may be a compensatory mechanism for early diabetic vascular injury. which suggest omentin may act as potential markers for assessing endothelial dysfunction and identifying high risk of cardiovascular complications among asymptomatic prediabetic individuals.