[Changes of endothelium-dependent vasodilation in patients with impaired glucose tolerance and type 2 diabetes].

OBJECTIVE

To investigate the changes of endothelium-dependent flow-mediated dilation (FMD) in patients with impaired glucose tolerance (IGT) and Type 2 diabetes (T2DM) and its influencing factors.

METHODS

The patients with IGT and T2DM were divided into IGT group (n=36), T2DM without vascular complication group (DM1;n=57), and T2DM with vascular complication group (DM2;n=31). And 25 normal subjects served as controls (NC group). The FMD was measured by high resolution ultrasound.The serum levels of tumor necrosis factor-alpha (TNF-alpha) and high sensitive C-reactive protein (hs-CRP) were detected with ELISA, and nitric oxide (NO) with Griess Reaction. The serum glucose, lipids, and other indexes were also detected.

RESULTS

Compared with the NC group, the serum levels of triglyceride (TG) total cholesterol (TC), low density lipoprotein-cholesterol (LDL-C), hs-CRP, and TNF-alpha significantly increased (P<0.05), but the serum levels of high density lipoprotein-cholesterol (HDL-C), the NO, and FMD significantly decreased (P<0.05) in the IGT, DM1, and DM2 group. With the progress of diabetes, FMD level descended. Pearson correlation analysis showed a negative correlation between FMD and glycosylated hemoglobin (HbA1c), insulin resistant index (HOMA-IR),TG,TC,hs-CRP, and TNF-alpha (P<0.01), but a positive correlation between FMD and NO,HDL-C (P<0.01) in IGT and T2DM patients. In multiple linear stepwise regression with FMD as dependent variable, NO,HbA(1)c,HDL-C,HOMA-IR, TNF-alpha, and hs-CRP showed a significant association with FMD (P<0.01).

CONCLUSION

Endothelium-dependent vasodilation is impaired in patients with IGT and T2DM,which is associated with hyperglycaemia, insulin-resistance, hyperlipemia, and inflammation.