| Background and objectives:Impaired glucose tolerance (IGT) is widely postulated as an important risk marker for CVD and is near to T2DM in regard of carrying CVD risk. The mechanism underlying angiopathy is triggered as early as in the stage of IGT. However, there were few reports on the angiopathy in IGT so far, and much discrepancy existed among them, moreover, few study targeted to ultrasound arterial stiffness and PWV in IGT people. The present study attempted to investigate early angiopathy in IGT people, and the effects of CVD and its risk factors on the relationship between IGT and early angiopathy, and to realize clinically the potential mechanism of the early angiopathy through testing and analyzing relevant parameters of insulin resistance, oxidative stress and inflammation..Subjects and methods:A single 75 gram glucose tolerance test(OGTT) was used to screen IGT individuals in the selected people who had previous dysglycaemia but no intervention taken, or carried obvious CVD risk factor(s). Their medical history and some concerned physical items were recorded as well at clinical visit. Blood samples were obtained for fasting lipid profile measurement. The blood levels of MDA, PAI-1, CRP, IL-10, AAG, and OGTT 2 hour MDA were also determined. AS surrogates and arterial distensibility were detected by ultrasound. The latter included stiffness index (SI), arterial compliance(AC), pressure-strain elastic modulus (Ep) and Young's elastic modulus(YEM). PWVs were examined by special apparatus made by Colin Corporation and five PWV indexes: HB(heart to branchial), HC(heart to carotid),LBA(branchial t oankle on the left), RBA(branchial to ankle on the right) and AI(augmentation index) were included. Framingham Scale Equation was used to evaluate 10 year risk of CHD.Some variables were appropriately transformed into numeric value, then monovariate or non-parameter analysis tested the difference of aforementioned parameters among three glucose tolerance categories. Mono- or multivariate analysis and monovariate or partial correlation analysis were carried out to test the effects of CVD and its traditional risk factors on the relationship of IGT with the surrogates of angiopathy. The differences of insulin resistance, oxidative stress and inflammation among three categories were also tested for statistic significance by non-parameter analysis. Correlation analysis was introduced to test statistically the relationship of glycaemia with those pathogenic parameters as well as the relationship between the angiopathic surrogates and the pathogenic parameters.Results:97 cases of NGT, 51 IGT and 73 T2DM were found in the screened population according to the WHO diabetes criteria issued in 1999. Elevated prevalence of HBP, SBP, WHR were found in IGT and T2DM groups in comparison with NGT. Both mIMT and ASS were increased significantly in IGT group compared with NGT group (mIMT: 1.00±0.32 vs. 0.92±0.25mm, P<0.05; ASS: 3.80±3.35 vs 2.5112.60, P<0.05), while ultrasound indexes of carotid stiffness did not show significant higher in IGT than NGT. Most of indexes indicated the deteriorate trend of angiopathy with progression of NGT to IGT and T2DM, the trend remained even after control of age, gender, and hypertension duration. The prevalence of anticipated 10% or higher risk for CHD were 22%, 40%, 60% in NGT, IGT and T2DM groups, and T2DM had a higher prevalence than NGT with significance (P<0.01) but similar to IGT (P>.05).ASS, mIMT, mSI and HB increased with FBS, ASS, mIMT, HC and HB increased with OGTT2h after the two blood glucose were quintiled. FBS correlated well with ASS and mIMT, so did OGTT2h with ASS, mIMT, mSI, HC, HB positively. Partialcorrelation revealed that the correlation of OGTT2h with ASS, HB or HC was independent of FBS, no angiopathic index was correlated with FBS independent of OGTT2h. Multivariate analysis showed that the independent predictors for angiopathic variables comprised mainly age, systolic pressure and cholesterol, and less importantly, diabetes, HDL-C(protective effect),...
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