Abstract:

Objective    To explore the status of endothelial dysfunction and early atherosclerosis in first-degree relatives(FDRs) with normal glucose tolerance of type 2 diabetes mellitus(T2DM) patients, investigate the relationship of them, and analyze the related factors by correlation analysis. Methods    48 FDRs with normal glucose tolerance of T2DM patients were enrolled in the observation group, and 38 volunteers with no family history of diabetes and impaired glucose tolerance were involved in the control group. Fasting blood-glucose(FBG), triglyceride(TG), and 2-hour postprandial sugar(P2hBG) were observed by the enzyme technique. Insulin(FINS) was determined by chemoiluminesence immunoassay, while dimethylarginine(ADMA) and endothelin-1(ET-1) were detected by ELISA. Insulinresistance(IR), islet β  cell function index (IS) and islet cells sensitive index(ISI) were calculated by homeostasis model assessment, and the atherogenic index of plasma(AIP) was calculated by the logarithm of the ratio of plasma concentration of triglycerides to that of HDL-cholesterol (log［TG/HDL-C］). Flow-mediated dilation of the brachial artery(FMD), carotid intima-media thickness (IMT),  pressure strain elasticmodulus(Ep), stiffness parameter(β) and arterial compliance(AC) were measured by high-resolution ultrasonography. Results    Compared with the controls, levels of ADMA,   ET-1,  TG,  Ln(FINS), Ln(HOMA-IR),  Ln(HOMA-IS),  AIP,  Ep and β were obviously higher(P﹤0.05), and levels of FMD and Ln(ISI) were apparently lower(P﹤0.05). The P2hBG level increased, while the AC level declined. However, both  had no statistical difference (P>0.05).  Ep and β had positive correlations with ADMA and ET-1 and negative correlations with FMD(P<0.05).  After levels of TG, Ln(HOMA-IR), AIP, P2hBG and SBP were corrected, Ep, β and FMD had independent correlations with ADMA and ET-1(P<0.05). Conclusions    Endothelial dysfunction and early atherosclerosis exist in FDRs with normal glucose tolerance of T2DM patients. Early atherosclerosis has a co-linearity with endothelial dysfunction, and  independent correlations with serum ADMA and ET-1 levels. Therefore, serum ADMA and ET-1 levels may be  biological indictors for predicting early atherosclerosis.

Key words: Endothelial dysfunction; Atherosclerosis; Type 2 diabetes mellitus; First-degree relatives