葡萄糖耐量低减与动脉粥样硬化

目的　观察葡萄糖耐量低减 (IGT)与动脉粥样硬化 (AS)的关系。方法　在曾经有血糖异常升高 (但未达糖尿病标准 )、患有心血管疾病 (如冠心病、中风或高血压 )或其危险因素 (如血脂异常 )的人群进行 75g口服葡萄糖耐量试验 (OGTT)筛查IGT病人 ,并同时记录病史、体检。空腹血脂指标由自动生化分析完成。同时用B型超声检查双侧颈总动脉 ,观察内膜连续性、内膜 中层厚度 (IMT)、斑块等指标。结果　IGT组 (n =5 1)的内膜连续性比正常糖耐量 (NGT)组 (n =97)明显差 (P <0 .0 5 ) ,IGT组双侧平均IMT和动脉粥样硬化 (AS)积分均显著高于NGT组 (均P <0 .0 5 ) ,IGT的平均IMT异常增高的发病率显著高于NGT。但以上指标IGT与糖尿病组 (n =73 )差异无显著性。多元分析发现 ,IGT的AS指标增加效应经同时校正甘油三酯、胆固醇、冠心病史、中风史、吸烟、性别、体重指数仍具有显著意义 ;但是分别校正年龄、腰臀围比值、高密度脂蛋白胆固醇和高血压病史 ,三种AS指标有不同程度的减弱。结论　与NGT人群相比 ,IGT人群已经存在明显的AS表现 ,其程度与糖尿病类似。IGT的动脉粥样硬化现象独立于部分心血管危险因子和已经存在的心血管疾病。     

Does NIDDM increase the risk for coronary heart disease similarly in both low- and high-risk populations?

Summary Finland has marked regional differences in the occurrence of coronary heart disease (CHD). Although the causes for these differences in CHD mortality and morbidity in the Finnish population are unknown, it offers an excellent opportunity to investigate the effects of non-insulin-dependent diabetes mellitus (NIDDM) on CHD risk in two populations differing significantly with respect to the occurrence of CHD. Therefore, we carried out a 7-year prospective population-based study including a large number of patients with NIDDM (East Finland: 253 men and 257 women; West Finland: 328 men, 221 women) and corresponding non-diabetic subjects (East Finland: 313 men, 336 women; West Finland: 325 men, 399 women). In both study populations the presence of NIDDM increased significantly the risk for CHD events (CHD mortality or all CHD events including CHD mortality or non-fatal myocardial infarction). Diabetic men had 3–4 fold higher and diabetic women 8–11-fold higher risk for CHD than corresponding non-diabetic subjects. Both non-diabetic and diabetic subjects had odds ratios (East vs West) for CHD events of about 2 indicating a similar East-West difference in the CHD risk. Regional difference was quite similar in men and women. These results imply that factors related to NIDDM, independently of conventional risk factors and the occurrence of atherothrombosis in the background population, must play a major role in the pathogenesis of atherosclerotic vascular disease in NIDDM diabetes.Abbreviations CHD Coronary heart disease - NIDDM non-insulin dependent diabetes mellitus - MI myocardial infarction     

Haemostasis and carotid artery wall thickness in non-insulin dependent diabetes mellitus

The purpose of this study was to examine the associations of carotid artery intima-media wall thickness (IMT) with hemostatic proteins and cardiovascular risk factors (CVRFs) in participants with and without non-insulin dependent diabetes mellitus (NIDDM). IMT measurements were determined by high resolution B-mode ultrasound imaging of the carotid arteries in 921 participants with NIDDM and 11,964 non-diabetic participants aged 45-64 years. Fasting glucose, serum lipids and activated partial thromboplastin time, factor VIII fibrinogen, factor VII, antithrombin III, protein C, and von Willebrand factor measurements were made. Compared to non-diabetic participants, participants with NIDDM had a more adverse pattern of CVRFs and a more procoagulatory profile. Participants with NIDDM had 0.06 mm (8.1%) higher mean IMT compared to non-diabetic participants after adjusting for age and gender (P < 0.001). However, only plasma fibrinogen concentrations showed statistically significant positive associations with IMT in both groups. After adjusting for CVRFs and fibrinogen, mean IMT remained 0.04 mm (5.4%) higher in diabetic compared to non-diabetic participants. Despite the more procoagulatory profile in participants with NIDDM, only plasma fibrinogen concentrations were independently associated with mean IMT. The association of NIDDM with mean IMT was only partly explained by CVRFs.     

Prevalence and atherosclerosis risk in different types of non-diabetic hyperglycemia. Is mild hyperglycemia an underestimated evil?

So far little is known about the importance of different types of non-diabetic hyperglycemia for the development of macrovascular disease. The aim of this work was to examine the intima-media thickness (IMT) of the common carotid artery (CCA), a well-accepted marker of atherosclerosis, as well as various risk factors for atherosclerosis in non-diabetic subjects with isolated fasting (IFH; n=67), isolated postchallenge (IPH; n=82) and combined hyperglycemia (CH; n=88) in comparison to normoglycemic (NG; n=265) controls. Subjects were participants of the RIAD study (Risk Factors in IGT for Atherosclerosis and Diabetes). IMT in the IPH (IMTmean: 0.89+/-0.02 mm; IMTmax: 1.01+/-0.02 mm; mean+/-SEM) and CH group (IMTmean: 0.91+/-0.02 mm; IMTmax: 1.03+/-0.02 mm) was significantly increased vs. the NG (IMTmean: 0.82+/-0.01 mm; IMTmax: 0.94+/-0.01 mm) and IFH group (IMTmean: 0.81+/-0.02 mm; IMTmax: 0.90+/-0.03 mm). IMT of the IFH group was similar to the normoglycemic controls. Subjects in the first and second tertile for postchallenge plasma glucose have similar carotid IMT irrespective of the level of fasting plasma glucose. The individuals of the third tertile for 2 h plasma glucose, whether in the first, second or third tertile of fasting plasma glucose, showed the same carotid IMT, which was significantly higher than all other groups, except for the one with lowest tertile for fasting and postchallenge plasma glucose. Except for total cholesterol and von Willebrand factor the levels of all other risk parameters were significantly higher in the hyperglycemic groups in comparison to the normoglycemic controls. Among the hyperglycemic subjects the CH group was at the highest risk for atherosclerosis with significantly increased levels of plasma triglycerides, fibrinogen, PAI-1, albuminuria, HDL-triglycerides, free fatty acids, insulin and proinsulin, and significantly reduced HDL-cholesterol in comparison to the normoglycemic controls. In summary, postchallenge hyperglycemia within the non-diabetic range is associated with atherosclerosis, as measured by the increased intima-media thickness of the common carotid artery. Furthermore, cardiovascular risk factors are significantly raised in all types of non-diabetic hyperglycemia.     

Major determinants of the carotid intima-media thickness in type 2 diabetic patients: age and body mass index

The present study has been designed to quantify and compare right and left carotid intima-media thicknesses (IMT) in type 2 diabetics and healthy controls. It was also intended to investigate the effects of various risk factors on the carotid IMT in these subjects. A total of 122 subjects; 70 patients with type 2 diabetes and 52 non-diabetic subjects as controls, were recruited for the study. Right and left common carotid artery stiffness indices were assessed with ultrasonography in both groups. Age, body mass index (BMI), duration of diabetes, cigarette smoking, lipid profile including lipoprotein a, Chlamydia pneumonia seropositivity, glycemic indices, fasting insulin levels, serum fibrinogen levels and presence of hypertension, coronary artery disease, degenerative complications of diabetes mellitus were all assessed in order to define their role as determinants of carotid artery IMT. The difference between the groups regarding mean carotid IMT was statistically significant for the left carotid arteries (p = 0.028) and borderline significance was found for the right carotid arteries (p = 0.055). Age has a very strong association with carotid IMT in diabetic patients (p < 0.0001) with univariate analysis. According to the results of multivariate analysis, age and BMI were found to be the most important independent determinants of carotid IMT for both sides. When age was excluded from the model, BMI and coronary artery disease were found to have strong association with IMT on the right (p = 0.0036 and 0.0249) and BMI was the only significant determinant for the left side (p = 0.0025). This study shows that carotid IMT is greater in diabetic subjects compared with healthy controls. For the diabetic subjects, age, BMI and presence of coronary heart disease have a strong influence on the atherosclerotic process of the carotid arteries.     

Lack of association between carotid intima-media thickness and methylenetetrahydrofolate reductase gene polymorphism or serum homocysteine in non-insulin-dependent diabetes mellitus

We assessed the contribution of the serum homocysteine (Hcy) level, an independent risk factor for vascular disease, and methylene tetrahydrofolate reductase (MTHFR) gene polymorphism to the variability of intimal-medial thickness (IMT) of the common carotid artery in middle-aged non-insulin-dependent diabetes mellitus (NIDDM) subjects. One hundred thirty NIDDM patients (60 males and 70 females) with a mean age of 53 +/- 10 years and a mean diabetes duration of 11.3 +/- 7.9 years were enrolled for the study. Exclusion criteria included liver, heart, kidney, or other major-organ disease. Fasting total serum Hcy, folate, and vitamin B12 and clinical chemistry analyte levels were measured. MTHFR polymorphism was determined by polymerase chain reaction (PCR). IMT and plaques or stenosis in the common carotid were measured by ultrasonography. Serum Hcy was inversely correlated with vitamin levels and was slightly higher in subjects with the Val/Val genotype versus Ala/Val and Ala/Ala (P = .02); no differences in genotype were found in subjects with folate or vitamin B12 at or above the median level. In univariate analysis, common carotid IMT was significantly associated with age (P = .00001), the body mass index ([BMI] P = .0003), uric acid (P = .004), systolic blood pressure (P = .03), glycemia (P = .03), and total cholesterol (P = .04). No significant association was found between serum Hcy or MTHFR polymorphism and IMT. In multiple regression analysis, age (P = .0001), uric acid (P = .03), glycemia, and the BMI (P = .05) were independently associated with IMT and explained about 42% of IMT variability. In 130 NIDDM patients without nephropathy, basal levels of serum Hcy, as well as MTHFR polymorphism, did not predict significant changes in common carotid IMT.     

Carotid intima-media thickness of young coronary patients.

BACKGROUND: Although a greater than normal intima-media thickness (IMT) has been found in older coronary patients, the data for younger patients are lacking. OBJECTIVE: To determine the carotid IMT in patients with premature myocardial infarction. METHODS: We measured IMT (common and internal carotid, carotid bifurcation) in 30 coronary patients, aged 30-50 years (mean 46 years), who had survived myocardial infarctions 1-9 years (mean 6 years) earlier, and in 30 age-matched men without clinically evident coronary heart disease (controls) by B-mode ultrasonography. Blood levels of lipoproteins, glucose, iron and transferrin, fibrinogen, tissue plasminogen activator (t-PA) antigen level and activity and plasminogen activator inhibitor (PAI-1) antigen level and activity were also determined. RESULTS: IMT in all segments of carotid arteries in the patients was significantly greater than that in the controls (P < 0.0001). The presence of atherosclerotic plaques was correlated to greater than normal carotid IMT. Other risk factors displaying statistically significant correlations to mean carotid IMT were t-PA antigen level and activity, PAI-1 antigen level and level of high-density lipoprotein cholesterol. CONCLUSIONS: The significant association between carotid IMT and coronary heart disease suggests that carotid and coronary atherosclerosis evolve simultaneously. Hence carotid IMT can be used as a predictor of coronary atherosclerosis.     

Coronary artery calcium versus intima-media thickness as a measure of cardiovascular disease among asymptomatic adults (from the Rancho Bernardo Study)

Detection and quantification of subclinical coronary heart disease by noninvasive imaging techniques offers the potential for earlier diagnosis with targeted prevention and therapy. This study, designed to determine the extent to which carotid artery intima-media thickness (IMT) predicts coronary artery calcium (CAC) in asymptomatic older adults, included 141 men and 137 women > or =55 years of age with no previous coronary heart disease who had B-mode ultrasound of the common and/or internal carotid arteries in 1997 to 1999 to measure IMT and electron beam computed tomographic scanning in 2001 to 2002 to measure CAC score. Overall, 29% of participants had a severe plaque burden (CAC score >400); 50% of these had a CAC score >800. IMT of the common and internal carotid arteries was significantly associated with the CAC score measured an average of 3 years later. The ability to correctly identify subjects with a severe CAC score (sensitivity) was 50% to 60% for an IMT of the internal or common carotid artery > 80th percentile (internal carotid IMT > or =1.9 mm and common carotid IMT > or =1.04 mm). Specificity, the ability to correctly identify those who did not have a severe CAC score (> or =400), was approximately 75%. In conclusion, IMT of the carotid arteries predicted the severity of CAC burden an average of 3 years later in community-dwelling asymptomatic older adults.     

Intimal medial thickness of the carotid artery in South Indian diabetic and non-diabetic subjects: the Chennai Urban Population Study (CUPS)

Aim/hypothesis. Increased intimal medial thickness (IMT) of the carotid arteries is considered a useful marker of atherosclerosis. The aim of this study was to compare the intimal medial thickness values in urban non-diabetic and diabetic South Indian subjects who have a high risk of coronary artery disease.¶Methods. The subjects for this study were 140 diabetic and 103 non-diabetic control subjects matched with them for age and sex selected from The Chennai Urban Population Study which is an ongoing epidemiological study. Intimal medial thickness of the right common carotid artery was determined using high resolution B mode ultrasonography.¶Results. The mean intimal medial thickness values of the diabetic subjects (0.95 ± 0.31 mm) were significantly higher than those of the non-diabetic (0.74 ± 0.14 mm) subjects (p < 0.001). Both in the normal and diabetic subjects, these values increased with age. At any given age, the diabetic subjects had higher values than the non-diabetic subjects but the difference reached statistical significance after age 50 years (p < 0.05).¶Intimal medial thickness showed a correlation with age, total cholesterol, LDL cholesterol, waist:hip ratio and systolic blood pressure in non-diabetic subjects and with age and duration of diabetes in the diabetic subjects. Multivariate linear regression analysis showed that age and diabetes were the major risk factors for intimal medial thickness.¶Conclusion/interpretation. Diabetic subjects have higher intimal medial thickness values than non-diabetic subjects. Diabetes and age are the most important risk factors associated with increased intimal medial thickness in this South Indian cohort. [Diabetologia (2000) 43: 494–499]     

Insulin resistance contributes to carotid arterial wall thickness in patients with non-insulin-dependent-diabetes mellitus

The aim of this study was to clarify whether insulin resistance contributes to atherosclerosis in patients with non-insulin-dependent diabetes mellitus (NIDDM). Fifty-three NIDDM patients (36 males and 17 females, 53+/-10 years old (mean+/-SD)) were studied. As an index of atherosclerosis, we measured the average thickness (IMT) as well as basal thickness excluding the maximum thickness and the height of the maximum thickness of the carotid artery wall. Euglycemic hyperinsulinemic glucose clamp was conducted for 90 min to evaluate average glucose infusion rate (GIR) as an index of insulin sensitivity in the peripheral tissues. For another 180 min after intake of oral glucose load with 0.3 g/kg, the euglycemic hyperinsulinemic clamp was continued to measure ratio of splanchnic glucose uptake (SGU) as an index of insulin sensitivity of the liver. The patients were separated into three activity groups according to the grade of their leisure-time physical activity. GIR (r = -0.32, p < 0.05) but not SGU (r=0.139) showed a significant inverse relationship with IMT. Multivariant regression analysis indicated that age and total cholesterol remain as independent risk factors for basal thickness and GIR as only independent risk factor for the height of the maximum thickness. Paralleling the degrees of habitual exercise (low, moderate, and high active group), GIR was higher (6.19+/-1.02, 6.38+/-1.38, 7.44+/-1.80, respectively) and IMT was lower (1.34+/-0.33 mm, 1.20+/-0.31 mm, and 1.12+/-0.29 mm, respectively) in male NIDDM as well as in female NIDDM. These data suggest that insulin resistance in the peripheral tissues but not the splanchnic tissues may independently contribute to carotid arterial wall thickness and especially to plaque lesion, and that habitual exercise might reduce insulin resistance leading to attenuation of atherosclerosis.     

Serum Homocysteine,MTHFR Gene Polymorphism,and Carotid Intimal-Medial Thickness in NIDDM Subjects

We assessed the contribution of serum homocysteine levels, an independent risk factor for vascular disease, and of the methylenetetrahydrofolate reductase (MTHFR) C677T mutation to the variability of carotid intimal-medial thickness (IMT) in patients with non–insulin-dependent diabetes mellitus (NIDDM). Ninety-five patients (33 males and 62 females, mean age 53 ± 10 years) without nephropathy or other vascular complications were enrolled. Fasting total serum homocysteine and other biochemical analytes were measured. The MTHFR polymorphism was determined by the polymerase chain reaction. Common carotid IMT and plaques or stenoses in the carotid district were measured by ultrasonography. Serum total homocysteine concentrations were higher in subjects with the mutant (Val/Val) genotype than in those with the Ala/Val plus Ala/Ala genotypes (P = 0.02). On univariate analysis, carotid IMT was significantly associated with age, body mass index (BMI), systolic blood pressure, and total cholesterolemia. No significant association was found between IMT and serum homocysteine or the MTHFR polymorphism, although a slightly greater IMT was observed in the homozygous Val genotypes. On multiple regression analysis, only age and BMI were independently associated with IMT and explained about 40% of IMT variability. The results did not change when the analysis was restricted to the subgroups with or without atherosclerotic plaques in the carotid district. In 95 Italian NIDDM patients without nephropathy, neither basal levels of serum total homocysteine nor the MTHFR C677T polymorphism predicted significant changes in common carotid intimal-medial thickness.     

颈动脉内中膜厚度及斑块与冠心病的相关性

目的探讨颈动脉内中膜厚度(IMT)及斑块与冠状动脉造影(CAG)结果的相关性,了解IMT在预测冠心病方面的价值。方法研究对象116名经CAG分为冠心病组和非冠心病组,超声观察颈动脉IMT及有无斑块形成并与CAG结果比较。结果非冠心病组与冠心病组比较患者颈动脉IMT、斑块指数均存在显著性差异(P<0．01),颈动脉IMT与冠状动脉狭窄程度呈正相关(r= 0．634,P<0．01)。颈动脉IMT对冠心病诊断有较高的敏感性及特异性。结论颈动脉超声可能是冠心病诊断的一项重要的辅助检查手段。     

Flow-mediated vasodilatation of the brachial artery and intima-media thickness of carotid artery in never-treated subjects.

AIM: Data on the association between brachial artery flow-mediated dilatation (FMD) and common carotid intima-media thickness (IMT) are contrasting. The present study investigated the relationship between FMD and IMT and carotid atherosclerosis in never treated subjects. METHODS: Seventy-seven subjects were investigated: 46 had no coronary heart disease (CHD) risk factors, 21 had only one, and 10 had more than one risk factor. IMT of the common carotid was measured by ultrasonography and FMD was evaluated according to standardized methods. RESULTS: IMT increased with increasing number of risk factors (0.66+/-0.12, 0.69+/-0.12 and 0.8+/-0.17 mm, respectively, ANOVA P<0.05). FMD decreased with increasing number of risk factors (10.44+/-5.2, 6.52+/-7.11 and 7.35+/-4.42%, respectively, P<0.05). Endothelium-independent vasodilatation was similar in the 3 groups. IMT and FMD did not correlate neither in subjects without risk factors (r=-0.151, P=0.3), nor in those with 1 (r=-0.196, P=0.4) or with 2 or more risk factors (r=-0.387, P=0.2), while in the group as a whole the correlation was borderline significant (r=-0.217, P=0.058). Eleven subjects had carotid atherosclerosis and higher values of IMT, but not reduced FMD. In multiple regression analysis, diabetes and IMT, but not FMD, were associated with carotid atherosclerosis. CONCLUSIONS: The present findings indicate that, in never treated subjects, FMD is not strictly associated with IMT or atherosclerosis of the carotid arteries.     

Neointimal proliferation within carotid stents is more pronounced in diabetic patients with initial poor glycaemic state

Aims/hypothesis We studied the influence of initial hyperglycaemia on neointimal proliferation within carotid Wallstents.Methods A total of 112 patients were followed by duplex sonography after carotid stenting for 24 months. Patients were assigned to three groups: non-diabetic subjects (group A) and diabetic patients, who were assigned according to their baseline HbA₁c values, to group B1(HbA₁c6.5%) or group B2 (HbA₁c>6.5%).Results At baseline the groups did not differ with respect to other vascular risk factors and residual stenosis on angiograms. The maximal thickness of the layer between the stent and the perfused lumen was measured at the duplex follow-ups. At 3 months the typical ultrasonic structure of the neointima was clearly discernible. From this point on, group B2 differed significantly (p<0.001) compared with B1 and A with respect to the maximal thickness of neointima and the time course of its ingrowth: group A vs B1 vs B2 was 0.51±0.39 vs 0.52±0.33 vs 0.56±0.35 at 3 months, 0.91±0.27 vs 0.90±0.38 vs 1.14±0.48 at 6 months, 1.02±0.24 vs 0.97±0.34 vs 1.21±0.44 at 12 months and 1.09±0.23 vs 1.10±0.31 vs 1.23±0.37 at 24 months.Conclusion/interpretation Initial hyperglycaemia seems to be a predictor of more pronounced neointimal proliferation after carotid stenting independent of diabetes. As intimal hyperplasia is known to be responsible for stent restenosis, strict optimisation of the hyperglycaemic state should be aimed at before elective carotid artery stenting.Abbreviations CCDS Colour coded duplex sonography - CHD coronary heart disease - PAOD peripheral arterial occlusive disease - CCA common carotid artery - ICA internal carotid artery - IMT intima-media thickness - UKPDS United Kingdom Prospective Diabetes Study Group     

Impaired fasting glucose is not a risk factor for atherosclerosis.

AIM: To determine a new category of dysfunctional glucose homeostasis - impaired fasting glucose (IFG) - introduced by the American Diabetes Association (ADA) and the World Health Organization (WHO) defining those with abnormal but nondiabetic fasting glucose values and with a possible risk for developing diabetes. It is not known whether IFG is a risk factor for atherosclerosis, as is impaired glucose tolerance (IGT). METHODS: In this case-control cross-sectional study in which the oral glucose tolerance (75-g OGTT) and the carotid intima-media thickness (IMT) with B mode ultrasound, as a marker of atherosclerosis, were measured, together with HbA1c, lipids, plasminogen activator (PAI), insulin and proinsulin concentrations in blood plasma. Out of 788 subjects of the risk factors in IGT for Atherosclerosis and Diabetes (RIAD) study we found 104 IFG cases that were compared to 104 controls with fasting plasma glucose (FPG)<6.1 mmol/l, matched for age, sex and body mass index. Subjects with 2h postprandial (pp) plasma glucose > or = 11.1 mmol/l were excluded. The rest were subdivided into those with 2h plasma glucose < 7.8 mmol/l (63 pairs, NGT) and those with plasma glucose > 7.8 mmol/l and < 11.1 mmol/l (41 pairs, IGT). RESULTS: The case and control groups showed no significant differences in the major risk factors except for waist-to-hip ratio (WHR) which was higher in the IFG with NGT. IFG with NGT exhibited significantly higher levels of HbA1c, true insulin and proinsulin. In IFG with IGT, only HbA1c and proinsulin were significantly increased vs. controls. IMT was in the same range for cases and controls in both subgroups. However, IMT mean and IMTmax were significantly increased in IFG with IGT vs. IFG with NGT (0.95 mm vs. 0.80 mm and 1.10 mm vs. 0.90 mm). Cumulative distribution analysis of IMT illustrates that IMT in IFG with IGT is more shifted to higher artery wall thickness than in IFG with NGT. CONCLUSIONS: In our case-control study IFG alone was not related to increased IMT. Only IFG in a combination with IGT exhibited atherosclerotic changes of the carotid arteries. IFG is not analogous to IGT as a risk factor for atherosclerosis.     

颈动脉粥样硬化与冠心病关系的探讨

目的:研究颈动脉粥样硬化与冠心病的关系.方法: 超声检查205例冠心病(冠心病组)和41例风湿性心脏病或其它体检患者(非冠心病组)的颈动脉,测量血管的直径、内-中膜的厚度(intima-media thickness, IMT),血流的速度等参数,观察斑块的有无及形成情况,了解颈动脉粥样硬化与冠心病以及非冠心病患者的关系.结果:确诊冠心病的患者205例中颈动脉超声有病变者195例,占 95.12%.其中冠状动脉三支病变者97例中颈动脉有病变者96例,达98.97%.41例非冠心病患者中颈动脉有病变者 11例,占26.83%,颈动脉无病变者30例,占73.17%.结论:冠心病和颈动脉粥样硬化存在着明显的相关性,颈动脉超声诊断技术对诊断冠心病有重要意义.     

Regulation of low-density lipoprotein particle size distribution in NIDDM and coronary disease: importance of serum triglycerides

Summary An increase of low-density lipoprotein triglycerides (LDL-Tg) was found to be an independent coronary artery disease (CAD) risk factor for non-insulin-dependent diabetic (NIDDM) patients in a recent prospective study. We examined the composition and size of LDL particles in 50 NIDDM men with angiographically verified CAD (NIDDM+ CAD+) and in 50 NIDDM men without CAD (NIDDM+ CAD–) as compared to 50 non-diabetic men with CAD (NIDDM– CAD+) and 31 non-diabetic men without CAD (NIDDM– CAD–). The groups had similar ranges of age and BMI LDL particle size was determined by gradient gel electrophoresis, and LDL was isolated by sequential ultracentrifugation for compositional analyses. Serum Tg was increased in NIDDM patients as compared to non-diabetic subjects (p<0.05), and in patients with CAD as compared to subjects without the disease (p<0.05). LDL cholesterol was lower in NIDDM patients than in non-diabetic subjects (p<0.001). Mean diameter of LDL particles was less than 255 å, but closely comparable in all groups. The presence of NIDDM was associated with increases of Tg and protein but lowering of free cholesterol in LDL (p<0.005 for all). In multivariate regression analyses neither NIDDM nor CAD were associated with LDL particle size, but serum Tg was the major determinant of LDL size in both NIDDM and non-diabetic subjects (p<0.001). When the patients were divided into quartiles according to fasting serum Tg levels, the LDL particle size and free cholesterol content decreased, but Tg and protein contents of LDL particles increased from the lowest to the highest Tg quartile (analysis of variance p<0.001 for all). When the subjects were categorized into two groups according to the median of VLDL-Tg (1.10 mmol/l) LDL size was associated with VLDL-Tg in the high but not in the low VLDL-Tg group. We conclude that in NIDDM patients with or without CAD serum Tg is the major determinant of the properties of LDL particles. The clinical implication is that in NIDDM serum Tg should be as low as possible to prevent atherogenic changes in LDL.Abbreviations NIDDM Non-insulin-dependent diabetes mellitus - CAD coronary artery disease - HDL high-density lipoprotein - LDL low-density lipoprotein - VLDL very-low-density lipoprotein - apoB apolipoprotein B - HL hepatic lipase - LPL lipoprotein lipase - CETP cholesteryl ester transfer protein - PL phospholipids - ANOVA analysis of variance - Tg triglycerides - FC free cholesterol     

颈动脉超声在诊断冠心病合并2型糖尿病中的应用价值

目的探讨颈动脉超声在冠心病合并2型糖尿病中的应用价值。方法将研究对象分为合并2型糖尿病和不合并2型糖尿病的冠心病组，超声观察颈动脉血流参数、内中膜厚度（IMT）及斑块指数（PI），并与冠状动脉造影结果对照。结果与单纯冠心病患者相比，合并2型糖尿病的冠心病患者颈动脉内径和血管阻力指数均增加（P〈0.05），IMT及PI随冠状动脉造影病变程度的增加而显著增加（P〈0．05）。结论颈动脉超声可以间接判断冠心病合并2型糖尿病患者冠状动脉血管病变的严重程度，可作为诊断合并2型糖尿病的冠心病的一项辅助检查方法。     

Effect of oral postmenopausal hormone replacement on progression of atherosclerosis : a randomized, controlled trial

-Postmenopausal hormone replacement therapy (HRT) is associated with low cardiovascular morbidity and mortality in epidemiological studies. Yet, no randomized trial has examined whether HRT is effective for prevention of coronary heart disease (CHD) in women with increased risk. The objective of this study was to determine whether HRT can slow progression of atherosclerosis, measured as intima-media thickness (IMT) in carotid arteries. Carotid IMT is an appropriate intermediate end point to investigate clinically relevant effects on atherogenesis. This randomized, controlled, observer-blind, clinical, single-center trial enrolled 321 healthy postmenopausal women with increased IMT in >/=1 segment of the carotid arteries. For a period of 48 weeks, subjects received either 1 mg/d 17ss-estradiol continuously plus 0.025 mg gestodene for 12 days every month (standard-progestin group), or 1 mg 17ss-estradiol plus 0.025 mg gestodene for 12 days every third month (low-progestin group), or no HRT. Maximum IMT in 6 carotid artery segments (common, bifurcation, and internal, both sides) was measured by B-mode ultrasound before and after intervention. HRT did not slow IMT progression in carotid arteries. Mean maximum IMT in the carotid arteries increased by 0.02+/-0.05 mm in the no HRT group and by 0.03+/-0.05 and 0.03+/-0.05 mm, respectively, in the HRT groups (P:>0.2). HRT significantly decreased LDL cholesterol, fibrinogen, and follicle-stimulating hormone. In conclusion, 1 year of HRT was not effective in slowing progression of subclinical atherosclerosis in postmenopausal women at increased risk.     

Carotid intima-media thickness in patients with isolated coronary artery ectasia

OBJECTIVE: Carotid artery intima-media thickness (IMT) is now widely used as a surrogate marker for atherosclerotic disease. Carotid IMT measured by ultrasound has been shown to be correlated with coronary artery disease as defined by angiography. However, the relation between carotid IMT and isolated coronary artery ectasia (CAE) has not been investigated. The aim of our study was to assess this relation. METHODS: Twenty-five patients with isolated CAE without stenosis and 25 control subjects with angiographically normal coronary arteries were included in this study. These were examined by B-mode ultrasound to measure the IMT at the far wall of the common carotid artery. RESULTS: Patients with isolated CAE had significantly higher carotid IMT compared to control subjects with angiographically normal coronary arteries (0.95+/-0.12 versus 0.71+/-0.10mm respectively, p<0.0001). In addition, we detected a significant positive correlation between the presence of CAE and carotid IMT (r=0.748, p<0.001). CONCLUSION: We have shown for the first time an association between increased carotid IMT and isolated CAE, suggesting that atherosclerosis may be involved in the pathogenesis of isolated CAE in the adult population.