Study On Relationship Between Impaired Glucose Metabolism And Carotid Intima-media Thickness

Objective To evaluate the relation of carotid IMT to impaired glucose metabolism, atherosclerosis risk factors and C-reactive protein level, one of the inflammation marker. Method One hundred and forty-nine subjects aged 30-70 years old, who had high risk for type 2 diabetes but did not know diabetes before, received 75-g oral glucose tolerance test(OGTT), then were divided into three groups: NOT, IGT and DM according to the OGTT results. CRP level and some biochemical parameters (including TC, TG, HDL-CH, fasting insulin, HbAlc) were measured. The IMT of the common carotid artery (CCA), internal carotid artery (ICA) and external carotid artery (EGA) were measured as well as the carotid plaque, wall surface and wall texture were examined using B-mode ultrasonography. Results1. According to the results of OGTT, the subjects were divided into NGT group (n=45), IGT group (n=60) and newly diagnosed type 2 DM group (n=44). Subjects in the three groups were matched well in age, sex, BMI, SBP and DBF except that subjects with HT in IGT group were more than in NGT and DMgroup. Biochemical examination showed that FPG, 2-hPG, HbAlc, TC level and HOMA-IR (calculated according to the value of fasting insulin and FPG) were higher in DM group than those in NGT and IGT group. 2-hPG was higher in IGT group than that in NGT group. TG, HDL-CH and fasting insulin were not statistically different among three groups.2. The mean value of IMTCcA in NGT, IGT and DM group was 0.76mm, 0.85mm and 0.85mm, respectively. IMTCcA increased significantly in newly diagnosed DM group and IGT group, compared with NGT group (p<0.05), and subjects whose carotid wall were not smooth or continuous in DM and IGT group were more than in NGT group too. The carotid IMT, carotid wall smoothness and continuity were not statistically different between DM and IGT group.3. The mean value of CRP level in NGT, IGT and DM group was 0.28 mg/dl, 0.34 mg/dl and 0.37mg/dl, respectively. The CRP level in DM group was significantly higher than that in NGT group (p=0.017). In DM group, there were statistically significant positive trends between tertiles of CRP level and IMTccA,IMTicA(p<0.01).4. In univariate analysis, 1-hPG, 2-hPG, TC and postchallenge glycemic spikes(PGS) were found to be significantly positively correlated to IMTccA in total group, after age and sex adjustment.In multivariate regression analysis, 2-hPG, age, HOMA-IR and CRP were found to be independent determinant of IMTccA-5. All examined glycemic parameters except FPG showed statistically significant odds ratio (OR) in relation to abnormal IMT (IMT>0.9mm), whereas the OR of 2-hPG is the strongest one. In logistic regression analysis, 2-hPG, PGS, CRP and HBP were found to be independent determinant of abnormal IMTccA-Conclusions1. IMTccA increased significantly in newly diagnosed DM group and IGT group. It could be concluded that the early atherosclerosis might have started at IGT stage.2. The CRP level in DM group was significantly higher than that in NGT group. In DM group, the CRP level was associated with both IMTccA and IMTjcA- It is suggested that chronic subclinical inflammation could have effect on atherogenesis.