Cardiovascular autonomic neuropathy associated with carotid atherosclerosis in Type 2 diabetic patients.

AIMS: To clarify if cardiovascular autonomic neuropathy is associated with carotid artery atherosclerotic plaques in Type 2 diabetic patients. METHODS: Cardiovascular autonomic nerve function was related to carotid artery ultrasound in 61 Type 2 diabetic patients 5-6 years after diagnosis of diabetes. RESULTS: Cardiovascular autonomic neuropathy [abnormal age corrected expiration/inspiration (E/I) ratio or acceleration index (AI)] was found in 13/61 (21%) patients. Patients with cardiovascular autonomic neuropathy showed increased degree of stenosis in the common carotid artery (24.6 +/- 13.2% vs. 14.7 +/- 9.2%; P = 0.014) and a tendency towards a higher plaque score (4.0 +/- 1.7 vs. 3.2 +/- 1.6; P = 0.064). Controlled for age, AI correlated inversely with degree of stenosis (r = -0.39; P = 0.005), plaque score (r = -0.39; P = 0.005), and mean (r = -0.33; P = 0.018) and maximum (r = -0.39; P = 0.004) intima-media thickness in the common carotid artery. In contrast, E/I ratio correlated only slightly with mean intima-media thickness in the common carotid artery (r = -0.28; P = 0.049). CONCLUSIONS: Cardiovascular autonomic neuropathy was associated with carotid atherosclerosis in Type 2 diabetic patients. Abnormal E/I ratios reflect efferent structural damage to parasympathetic nerves whereas abnormal AI reflects afferent autonomic dysfunction possibly due to impaired baroreceptor sensitivity secondary to carotid atherosclerosis.     

Decrease in carotid intima-media thickness in hypothyroid patients after normalization of thyroid function

OBJECTIVE: This case-control study was carried out to assess whether levothyroxine (L-T4) replacement might cause regression of the enhanced atherosclerosis seen in hypothyroid patients. PATIENTS AND METHODS: Intima-media thickness (IMT) in the common carotid artery (CCA) was measured from digitalized still images taken during scanning by high-resolution ultrasonography as an indicator of early atherosclerosis. Thirty-five hypothyroid patients were examined for their CCA IMT before and 1 year after normalization of thyroid function by L-T4 replacement. As control, 35 healthy subjects were enrolled from among the participants in a local health-check programme conducted at the Osaka City University Hospital. RESULTS: Basal CCA IMT was significantly higher in hypothyroid patients [0.635 +/- 0.018 (mean +/- SE) mm] than in control subjects (0.559 +/- 0.021 mm, P < 0.005). After 1 year of euthyroidism, 34 out of 35 patients showed a significant decrease of CCA IMT, to 0.552 +/- 0.015 mm (P < 0.0001), a level comparable to normal controls. CCA IMT change was closely associated with basal levels of total cholesterol (r = -0.472, P= 0.0031), low-density lipoprotein (LDL) cholesterol (r = -0.441, P= 0.0076) and the total/HDL cholesterol ratio (r =-0.435, P= 0.0057), but not with any of the other variables measured except for age (r = -0.353, P= 0.0296). CONCLUSIONS: This study demonstrated that L-T4 treatment might have the potential to reverse the progression of atherosclerosis in hypothyroid patients. Furthermore, it suggests that increased levels of LDL cholesterol and the total/HDL cholesterol ratio have an important role in the increased common carotid intima-media thickness in hypothyroid patients.     

Association of carotid hemodynamics with risk of coronary heart disease in a Taiwanese population with essential hypertension

BACKGROUND: The resistive index (RI) of the carotid artery is a hemodynamic parameter that depends on the degree of vascular resistance in hypertensive patients. The pulsatility index (PI) of the carotid artery was shown to be associated with microangiopathy in diabetic patients. In contrast to carotid intima-media thickness (IMT), no study has yet applied the carotid RI and PI to estimate coronary heart disease (CHD) risk. METHODS: Framingham risk scores (FRS) were determined for 62 patients (32 women; mean age 65 years (range 35-83)) with essential hypertension. Duplex sonography of the common carotid artery (CCA) was performed, with determination of RI, PI, and IMT. RESULTS: The mean FRS of all patients was 14.3% (range 1-30%), the mean IMT value of CCA was 0.89 +/- 0.23 mm, the mean RI was 0.71 +/- 0.07, and the mean PI was 1.46 +/- 0.39. FRS was found to have highly significant correlations with RI and PI (r = 0.47, P < 0.001 and r = 0.45, P < 0.001, respectively). The correlation between FRS and IMT was also significant (r = 0.41, P = 0.001). Multiple stepwise regression analysis showed that RI was an independent determinant of the risk of CHD. CONCLUSIONS: Although RI indirectly reflected the atherosclerotic process, the correlation between RI and CHD risk was comparable to the well-known correlation between cardiovascular event and carotid IMT. Hence, carotid RI can be used as a tool for risk stratification in Taiwanese patients with essential hypertension.     

Early vascular damage in primary hypoalphalipoproteinemia

The relationship between hypoalphalipoproteinemia (hypoalpha), a metabolic disorder characterized by reduced high-density lipoprotein (HDL) cholesterol levels, and atherosclerotic disease is not completely understood. We investigated arterial functional and structural changes in 19 subjects with hypoalpha (HDL cholesterol < or = 0.7 mmol/L for men and < or = 0.8 mmol/L for women; 13 men; 47 +/- 7 years) and in 21 healthy control subjects (11 men; 46 +/- 13 years). Brachial-artery flow-mediated vasodilation (FMV) and intima-media thickness (IMT) of the carotid and femoral arteries were determined in all subjects. FMV was significantly lower in hypoalpha than in controls (5.6% +/- 4.3% v 8.2% +/- 2.7%; P <.05). IMT was greater in hypoalpha than in controls at both the internal carotid (0.83 +/- 0.1 mm v 0.69 +/- 0.1 mm) and superficial femoral level (0.83 +/- 0.2 mm v 0.68 +/- 0.1 mm; both P <.05). FMV had a positive correlation with HDL cholesterol (r =.42, P =.06) and a negative one with triglycerides (r = -0.38, P =.01). An inverse relationship was found between HDL cholesterol and internal carotid and superficial femoral IMT (r = -0.64 and r = -0.60, respectively; P <.01 for both) and a positive one between triglycerides and internal carotid and superficial femoral IMT (r =.53 and r =.47, P <.05). In a multivariate regression analysis, brachial FMV was predicted by HDL cholesterol and brachial diameter (beta =.42 and -0.43, respectively; both P <.05). HDL cholesterol was the only significant predictor of internal carotid and superficial femoral IMT (beta = -0.45 and -0.49, respectively; both P <.05). In conclusion, subjects with primary hypoalpha, without overt cardiovascular disease, are characterized by an impaired endothelial function and by an increase in large-artery IMT.     

Plasma fibronectin level and its association with coronary artery disease and carotid intima-media thickness

BACKGROUND: The exact relation of fibronectin with coronary atherosclerosis is unknown. The aim of the present study was to examine the association of fibronectin level with presence and extent of coronary artery disease (CAD) and intima-media thickness (IMT) of common carotid artery (CCA). DESIGN: The IMTs of CCA of 86 patients who underwent coronary angiography were measured; traditional vascular risk factors were also evaluated in these patients. Fibronectin, lipids, C-reactive protein (CRP) and fibrinogen levels were determined. RESULTS: Plasma fibronectin levels of the patients with CAD were found to be significantly elevated compared to patients with normal vessels (0.46+/-0.11 and 0.36+/-0.12 mg/dl respectively, P = 0.001). Fibronectin levels were not associated with extent of CAD. No significant association was observed between fibronectin level and traditional risk factors. IMTs of right and left CCA in patients with CAD were found to be elevated compared to patients with normal vessels (0.89+/-0.1 mm compared with 0.76+/-0.1 mm, P = 0.001 and 0.93+/-0.2 mm compared with 0.71+/-0.1 mm, respectively P < 0.001). Fibronectin levels were positively correlated with CRP (r = 0.45, P < 0.001), low-density lipoprotein-cholesterol (r = 0.23, P = 0.03) and total cholesterol (r = 0.21, P = 0.04) levels and negatively correlated with high-density lipoprotein-cholesterol (HDL-C) levels (r = -0.24, P = 0.02). IMT of left CCA was positively correlated with CRP levels (r = 0.23, P = 0.04) and negatively correlated with HDL-C levels (r = 0.2, P = 0.04). Logistic regression analysis showed that age (P < 0.01) and fibronectin levels (P = 0.01) were independent predictors for the existence of CAD. CONCLUSIONS: The results suggest that fibronectin levels may be a significant predictor of CAD. However, it was shown that fibronectin levels were not associated with extent of CAD and IMT of CCA.     

Relationship of lipoprotein(a) with intimal medial thickness of the carotid artery in Type 2 diabetic patients in south India.

OBJECTIVE: The objective of this study was to investigate the association of lipoprotein(a) [Lp(a)] levels with intimal medial thickness (IMT) in Type 2 diabetic patients in south India. STUDY DESIGN: We studied 587 consecutive Type 2 diabetic patients at the M.V. Diabetes Specialities Centre, Chennai. The mean age of the study group was 55 +/- 10 years and 71.2% were males. IMT of the right common carotid artery was determined using high-resolution B mode ultrasonography. Lp(a) levels were measured using ELISA. Since the frequency distribution of Lp(a) was skewed, Lp(a) values were log transformed and the geometric mean was used for statistical analysis. The tertiles of IMT were determined to analyse the association of Lp(a) and other factors with IMT. RESULT: The mean Lp(a) level in the study patients was 18.9 +/- 3.1 mg/dl (geometric mean +/- sd) and the mean IMT of the study subjects was 0.93 +/- 0.19 mm (mean +/- sd). The prevalence of carotid atherosclerosis (defined as IMT > 1.1 mm) among subjects with elevated Lp(a) levels > 20 mg/dl was significantly higher compared with those with Lp(a) levels 相似文献   

Increased carotid intima-media thickness in patients with pheochromocytoma in comparison to essential hypertension

Catecholamines due to various mechanisms may contribute to the accumulation of collagen fibers and extracellular matrix in the arterial wall. The aim of this study was to compare intima-media thickness (IMT) of the common carotid artery (CCA) and carotid bifurcation (CB) in patients with pheochromocytoma, essential hypertension and healthy controls. Carotid ultrasound studies were carried out in 30 patients with pheochromocytoma matched for age and gender with 80 patients with essential hypertension and 40 normotensive controls. Significantly higher IMT was found in patients with pheochromocytoma and essential hypertension compared to controls when measured in the CCA (0.931+/-0.223, 0.825+/-0.146 and 0.738+/-0.113 mm; P<0.001; P<0.05), and only in patients with pheochromocytoma compared to controls in the region of CB (1.359+/-0.593, 1.095+/-0.311 and 0.968+/-0.247 mm; P<0.001; P=0.13). Higher IMT in patients with pheochromocytoma compared to patients with essential hypertension was also statistically significant in both carotid regions (both P<0.01). This difference remained significant after adjustment for all relevant clinical and biochemical covariates in the CCA (P=0.014) but disappeared in the region of CB (P=0.079). In summary, patients with pheochromocytoma have increased common carotid IMT when compared to patients with essential hypertension. This finding could be caused by the deleterious effects of the excess of catecholamines on the vascular wall growth and thickening.     

Quantitative measurement of carotid intima-media roughness--effect of age and manifest coronary artery disease

Atherosclerotic changes of the common carotid artery (CCA) may appear like irregularities of the intima-media thickness (abbreviated as IM roughness) in B-mode ultrasound. The purposes of the present study were to investigate whether the CCA IM roughness changes with age and differs between individuals presumed to be healthy and patients with coronary artery disease (CAD). METHODS AND RESULTS: Based on a new automatic identification (AI) program, the segmental intima-media thickness (IMT) and IM roughness of the CCA far wall were measured in B-mode images of 15 younger and 22 older volunteers presumed to be healthy, and 46 patients with known CAD. The mean and maximum CCA IMT were lowest in the young group (0.55+/-0.05; 0.65+/-0.06 mm), higher in the older group (0.77+/-0.16; 0.87+/-0.18 mm) and highest in CAD patients (0.88+/-0.18; 1.01+/-0.27 mm) (P<0.01 among all groups). The CCA IM roughness was greatest by far in the CAD patients (0.075+/-0.02 mm; P<0.01 vs. both groups) and increased only slightly with age (younger: 0.035+/-0.008 mm; older: 0.040+/-0.014 mm; P<0.05). Areas under the curve (AUC) of receiver-operating characteristic curves (ROC) predicting patients with CAD were higher for the CCA IM roughness (0.80) than for the mean (0.66) and maximum IMT (0.71). CONCLUSIONS: It is suggested that the CCA IM roughness increases with age, and helps to discriminate between individuals presumed to be healthy and patients with manifest CAD better than the CCA mean and maximum IMT.     

Carotid and femoral atherosclerotic lesions in patients with coronary heart disease confirmed by angiography

INTRODUCTION: Clinically evident atherosclerosis is preceded by preclinical changes in the arterial wall. These changes are characterised by increased thickness of the intima-media complex (IMT). AIMS: A complex ultrasound assessment of the peripheral vessels as well as an attempt to find ultrasound parameters correlating with the burden of atherosclerotic lesions of the coronary arteries. METHODS: 231 patients who underwent both coronary angiography and ultrasound examination of the following arteries: common carotid artery (CCA), carotid bulb and common femoral artery (CFA) were enrolled. The IMT value, presence of plaque and Doppler blood flow parameters were evaluated. Selected clinical and biochemical risk factors of atherosclerosis were assessed. Two groups of patients were analysed: 200 patients with coronary artery disease confirmed by angiography (study group), and 31 patients with normal coronary arteries (control group). RESULTS: Significantly higher values of the IMT in the peripheral arteries were observed in patients with coronary artery lesions than in those without (CCA - 0.91 vs 0.61 mm, carotid bulb -- 1.31 vs 0.67 mm, CFA -- 1.38 vs 0.63 respectively, p<0.0001). Atherosclerotic plaques were present only in patients with coronary artery disease. Additionally, IMT values of the CCA, carotid bulb and CFA were significantly higher in patients with severe coronary artery disease (three vessel disease) than in patients with lesions in one or two coronary arteries. CONCLUSIONS: Patients with coronary lesions present with increased IMT values and higher plaque occurrence. Complex ultrasound evaluation of different peripheral arteries (CCA, carotid bulb and CFA) may be used as part of the cardiovascular risk stratification.     

Irbesartan reduces common carotid artery intima-media thickness in hypertensive patients when compared with atenolol: the Swedish Irbesartan Left Ventricular Hypertrophy Investigation versus Atenolol (SILVHIA) study

BACKGROUND AND PURPOSE: Angiotensin II promotes cell growth and has been implicated in the development and maintenance of left ventricular (LV) hypertrophy and of structural vascular changes. We wished to examine whether an angiotensin receptor blocker (ARB) would influence structural vascular changes beyond the effects of blood pressure reduction. METHODS: Hypertensive patients with LV hypertrophy (age 55 +/- 9 years, blood pressure 162 +/- 19/104 +/- 8 mmHg, LV mass index 148 +/- 31 g m(-2); mean +/- SD) were randomized double-blind to the ARB irbesartan (n=52) or the beta(1) receptor blocker atenolol (n=56) for 48 weeks. Ultrasonography of the left and right common carotid artery (CCA) and echocardiography were performed at week 0 and 48. RESULTS: With similar reductions in blood pressure, CCA intima-media thickness (IMT) was reduced by irbesartan (from 0.92 +/- 0.14 by 0.01 +/- 0.10 mm, NS), whereas it was increased by atenolol (from 0.94 +/- 0.21 by 0.03 +/- 0.12 mm, P=0.018; P=0.002 between groups). CCA lumen diameter was less reduced by irbesartan than by atenolol. Thus, CCA intima-media area was reduced by irbesartan (from 21.3 +/- 5.0 by 0.90 +/- 2.45 mm(2), P=0.034) but not by atenolol (from 21.3 +/- 6.1 by 0.18 +/- 2.71 mm(2), NS; P=0.037 between groups). Changes in CCA IMT or area did not relate to changes in LV mass. CONCLUSIONS: The favourable effects by irbesartan on CCA IMT with an outward vascular remodelling suggest that angiotensin II mediates structural vascular changes, beyond the effects of blood pressure. This may be important in the prevention of cerebrovascular events.     

Low insulin sensitivity measured by both quantitative insulin sensitivity check index and homeostasis model assessment method as a risk factor of increased intima-media thickness of the carotid artery

The present study evaluated the association of ultrasonographic manifestations of carotid atherosclerosis with glucose status, various components of the insulin resistance syndrome, and insulin sensitivity measured by a novel quantitative insulin sensitivity check index (QUICKI = 1/[log(I0) + log (G0)]). Carotid ultrasonographic measurements were performed on 54 diabetic subjects, 97 subjects with impaired glucose tolerance and 57 normoglycemic subjects. QUICKI and insulin resistance measured by a HOMA (homeostasis model assessment) method had a high negative correlation (r = -0.995, P < 0.001). QUICKI was lower in diabetic subjects (0.319 +/- 0.022) than in subjects with impaired glucose tolerance (0.334 +/- 0.027) or normoglycemia (0.335 +/- 0.022, P = 0.002). There was an increasing trend in the mean and maximal intima-media thickness (IMT) of the common carotid artery (CCA) with worsening of glucose status. The maximal IMT of the CCA correlated inversely with QUICKI (r = -0.158, P = 0.027). The prevalence of severe CCA atherosclerosis (maximal IMT of the CCA > or = 1.2 mm) was 41% in men and 16% in women (P < 0.001). It was also associated with a long (> or =26 yr) smoking history. The prevalence of severe CCA atherosclerosis was 11% in the highest QUICKI tertile, 36% in the middle tertile, and 33% in the lowest tertile (P = 0.002). Systolic blood pressure was higher and high-density lipoprotein cholesterol lower in subjects with severe CCA atherosclerosis, compared with those without it. In multiple regression analysis, the adjusted odds ratio for severe CCA atherosclerosis was 5.7 (95% confidence interval, 2.2-15.1) in subjects in the two lowest tertiles of QUICKI, compared with those in the highest tertile.     

High prevalence of subclinical atherosclerosis in psoriatic arthritis patients without clinically evident cardiovascular disease or classic atherosclerosis risk factors

OBJECTIVE: To assess the presence of subclinical atherosclerosis in patients with psoriatic arthritis (PsA) without clinically evident atherosclerosis or its complications, and to assess whether demographic or clinical factors affect the development of atherosclerotic disease in a series of patients with PsA attended to in a community hospital. METHODS: Fifty-nine patients with PsA who fulfilled the Moll and Wright criteria were recruited from Hospital Xeral-Calde (Lugo, Spain). Patients seen during the period of recruitment who had classic cardiovascular risk factors or had experienced cardiovascular or cerebrovascular events were excluded. Fifty-nine healthy matched controls were also studied. Carotid artery intima-media thickness (IMT) and carotid plaques were measured in the right common carotid artery. The study was performed using high-resolution B-mode ultrasound. RESULTS: Patients with PsA exhibited greater carotid artery IMT than did matched controls (mean +/- SD 0.699 +/- 0.165 mm versus 0.643 +/- 0.111 mm; P = 0.031; difference of means 0.056; 95% confidence interval 0.005-0.108). Adjusted for age, the carotid IMT was correlated with age at the time of PsA diagnosis (partial correlation coefficient [r] = -0.264, P = 0.04), disease duration (r = 0.264, P = 0.04), total cholesterol (r = 0.233, P = 0.01), and low-density lipoprotein cholesterol (r = 0.243, P = 0.01). CONCLUSION: The present study demonstrates that patients with PsA without cardiovascular risk factors or clinically evident cardiovascular disease have a high prevalence of macrovascular disease in the form of increased carotid artery IMT compared with ethnically matched controls.     

Arterial dysfunction after treatment of coarctation of the aorta

The long term follow-up after successful coarctation repair has a late cardiovascular morbidity, includes systemic hypertension at rest or/and after exercise. The pathophysiology mechanisms responsible have not been well determined. We studied 70 normotensive subjects at rest (age, 14 +/- 5 y; pressure, 116 +/- 13/56 +/- 9 mmHg), who had an isolated coarctation with a good repair defined by the absence of gradient between upper and lower right limb (0.-26 mmHg). After exercise testing we defined two groups: Coa HT: Hypertension at exercise equal or over 200 mmHg, n = 20 (228 +/- 23 mmHg) and Coa HT: Normotensive at exercise = 10 (163 +/- 24 mmHg). These subjects were mached sex-age and blood pressure to 70 controls (age, 13 +/- 3 y; pressure, 115 +/- 10/56 +/- 6 mmHg). Using a high-resolution echographic technique, we assessed the systolic, diastolic diameter and the intima media thickness (IMT) of the common carotid artery (CCA) to define mechanical indexes: Cross sectional compliance (CSC), distensibility (CSD) and incremental elastic modulus (Einc) in each group. CCA pressure waveform and the local pulse pressure were determined in 32 subjects to define augmentation index (AI). The changes of the brachial artery diameter in response to reactive hyperaemia (flow mediated dilation: FDM) and to glyceryltrinitrate (GTNMD) were measured. The IMT was significantly increased in the Coa group (by 8%, p < 0.001) and higher in the Coa HT group compared with the Coa NT group (0.57 +/- 0.04 mm vs 0.54 +/- 0.05 mm, p < 0.05). The CSD was lower and the Einc was higher in both groups. The carotid pulse pressure amplitude was significantly higher in the Coa HT Group (41 +/- 14 vs 33 +/- 7 mmHg; p < 0.05). The AI was higher in both Coa repair groups. Both flow-mediated dilation (FMD) and GTN-mediated dilation (GTNMD) of the brachial artery were lower in the Coa group (respectively 5 +/- 3 vs 7 +/- 3%; p < 0.01; 16 +/- 8 vs 23 +/- 9%; p < 0.01). GTNMD was inversely correlated with maximum systolic blood pressure on exercise (r = 0.31, p = 0.03). The IMT of the CCA was related to the local pulse pressure in both groups of coarctation repair. The combination of distensibility decrease in the proximal arterial bed with an impairment of distal artery reactivity would account for the elevation of exercise blood pressure in subjects who had coarctation repair. The increase of local pulse pressure influences the carotid wall hypertrophy.     

Association between the corrected QT intervals and combined intimal-medial thickness of the carotid artery in patients with type 2 diabetes

The main purpose of this study was to determine whether cardiac autonomic neuropathy or coronary atherosclerosis is the more important factor affecting prolongation of the corrected QT interval (QTc) in patients with type 2 diabetes. We studied the association between QTc and the coefficient of variance of the heart rate variation (CV(RR)), which reflects cardiac autonomic neuropathy, and the combined intimal-medial thickness (IMT) of the common carotid artery, which reflects coronary atherosclerosis. In addition, we also investigated the relationship between the QTc and blood pressure, serum lipid concentrations, hemoglobin A(1C) (HbA(1C)) concentration, and duration of diabetes. We studied 75 patients with type 2 diabetes and 30 age-matched healthy individuals. The QT interval was measured in lead II of the electrocardiogram (ECG) and was corrected using Bazett's formula. Cardiac neuropathy was assessed by measuring CV(RR). Atherosclerosis was evaluated by measuring the combined IMT of the common carotid artery using B-mode ultrasonography. The QTc in patients with type 2 diabetes was significantly longer than in healthy individuals (P <.0001). The QTc more closely correlated with the IMT of the carotid artery (r = 0.7206, P <.0001), compared with CV(RR) (r = -0.3188, P =.0053), although both were statistically significant. The QTc also correlated positively with the systolic (SBP) and diastolic blood pressure (DBP) (r = 0.4371, P <.0001, r = 0.3632, P =.0014, respectively). Based on stepwise regression analysis with the QTc interval as the dependent variable, the IMT of the carotid artery had the most significant association with the QTc (beta = 0.6882, P =.0004). In conclusion, QTc prolongation in the setting of diabetes might be caused primarily by coronary atherosclerosis rather than by cardiac autonomic neuropathy.     

Arterial stiffness in type 1 diabetes mellitus is aggravated by autoimmune thyroid disease

OBJECTIVE: The aim of our study was to measure arterial stiffness in patients with Type 1 diabetes mellitus, its contributing factors and its relation to macrovascular arterial changes. MATERIALS AND METHODS: Thirty-one female Type 1 diabetic patients were studied; 11 had concomitant autoimmune thyroid disease although euthyroid during the study period. Stiffness was studied using applanation tonometry and pulse wave analysis for evaluation of systolic arterial pressure augmentation secondary to arterial stiffening and early wave reflection. Results were compared to 24 healthy individuals. In all patients, endothelium-related flow-mediated dilation (FMD) of the brachial artery and intima-media thickness (IMT) of the carotid artery were measured. RESULTS: Augmentation pressure (AP) and augmentation index (AI) were higher in Type 1 diabetic patients suggesting stiffer arteries compared to controls (AP: 5.8 +/- 3.6 vs 2.8 +/- 2.2 mmHg, p < 0.001; and AI:18.3 +/- 9 vs 11.1 +/- 8.8%, p = 0.004). The subgroup of diabetic patients with autoimmune thyroid disease presented stiffer arteries than those without (AP: 6.5 +/- 2.9 vs 5.5 +/- 3.9 mmHg, p < 0.05; and AI: 21.3 +/- 5.4 vs 16.7 +/- 10.3%, p < 0.05), though the two groups did not differ statistically by means of age, disease duration, hemoglobin A1c (HbA1c), lipid levels, FMD and IMT. In multiple regression analysis, variables independently associated to AI in the diabetes group were: age (p = 0.028), IMT of the carotid artery bifurcation (p = 0.045), disease duration (p = 0.031) and autoimmune thyroid disease (p = 0.015). No correlation was observed between AI and metabolic control, blood pressure, microalbuminuria, presence of retinopathy and endothelial function (FMD). CONCLUSIONS: Women with Type 1 diabetes have increased arterial stiffness, which indicates macroangiopathy. An independent correlation between these indices and carotid IMT was observed. Concomitant autoimmune thyroid disease seems to aggravate arterial compliance in these patients, a finding that merits further investigation.     

Increased intima-media thickness of the carotid artery in Japanese female type 2 diabetic patients with 'midband lipoprotein'

Among a number of different lipoprotein abnormalities, 'midband lipoprotein' migrating at a position between LDL and VLDL on polyacrylamide gel electrophoresis (PAGE), is an atherogenic lipoprotein and intima-media thickness (IMT) of the carotid artery is a useful marker of atherosclerotic diseases. The present study evaluated relationships between the presence of 'midband lipoprotein' and carotid IMT in subjects with type 2 diabetes. The average IMT of the carotid artery was determined from the means of maximal thicknesses of both left and right common carotid arteries, carotid bulb, and internal carotid artery using ultrasound B mode imaging in 118 Japanese patients (72 men, 46 women) and 43 healthy controls. Multivariate regression analyses indicated that the duration of diabetes and presence of 'midband lipoprotein' were independent determinants of carotid artery IMT in 46 female subjects with diabetes, and these subjects were then subclassified into midband-positive (n=24) and midband-negative (n=22) groups. IMT of the carotid artery was significantly different between midband-positive (0.98+/-0.32mm) and midband-negative (0.79+/-0.17mm) groups (P=0.02). These findings suggest that 'midband lipoprotein' is a possible risk factor for IMT of the carotid artery in Japanese female type 2 diabetic patients.     

A dietary and exercise intervention slows menopause-associated progression of subclinical atherosclerosis as measured by intima-media thickness of the carotid arteries

OBJECTIVES: The object of this study was to assess the effects of menopause and a diet/exercise intervention on subclinical atherosclerosis progression. BACKGROUND: Subclinical atherosclerosis has been linked to higher coronary heart disease and stroke rates and is greater among postmenopausal women according to cross-sectional analyses. Whether menopause is associated with an accelerated progression of subclinical disease is unknown, as is the extent to which lifestyle intervention can alter the course of progression. METHODS: Intima-media thickness (IMT) measures of the common carotid artery (CCA), internal carotid artery (ICA), and bulb segments of the carotid arteries were measured twice during the course of 4 years in 353 women from the Women's Healthy Lifestyle Project, a dietary and exercise clinical trial designed to prevent adverse risk factor changes through the menopause. A third measure was obtained 2.5 years later for 113 women. RESULTS: The progression of IMT was observed for the average of all segments (AVG), the CCA, and the bulb (0.007 mm/year, 0.008 mm/year, and 0.012 mm/year; p < 0.01 for all), but not for the ICA. Among controls, menopause was associated with accelerated IMT progression (0.003 mm/year for premenopausal women vs. 0.008 mm/year for perimenopausal/postmenopausal women for AVG IMT; p = 0.049). Additionally, among the 160 perimenopausal/postmenopausal women, the intervention slowed IMT progression (0.008 mm/year for the control group vs. 0.004 mm/year for the intervention group for AVG IMT; p = 0.02). Similar results were found for the CCA and bulb segments. CONCLUSIONS: These data demonstrate that the menopause transition is associated with accelerated subclinical atherosclerosis progression and that a diet/exercise intervention slows menopause-related atherosclerosis progression.     

Inverse correlation between activated protein C generation and carotid atherosclerosis in Type 2 diabetic patients.

AIMS: Activated protein C (APC) is a key regulator of the clotting system and immune responses. We studied the relationship between the degree of atherosclerosis as measured by the intima-media thickness (IMT) of carotid artery and APC generation in Type 2 diabetic patients. METHODS: Eighty-seven Type 2 diabetic patients and 35 control subjects participated. APC generation was assessed by the plasma APC-protein C inhibitor complex (APC-PCI) levels and the mean IMT of carotid artery was measured by ultrasonography. The plasma levels of the thrombin-anti-thromobin complex (TAT) and platelet-derived growth factor (PDGF) were measured by enzyme-linked immunoassays. RESULTS: Plasma TAT levels were significantly higher in diabetic patients [2.03 (1.12, 2.56) ng/ml, median (25th, 75th percentile)] compared with control subjects [0.85 (0.55, 2.08) ng/ml, P < 0.01]. Plasma APC-PCI levels were significantly lower in diabetic patients [0.93 (0.74, 1.22) ng/ml], than in control subjects [1.66 (1.25, 2.36) ng/ml, P < 0.001]. The mean IMT was significantly increased in diabetic patients (0.881 +/- 0.242 mm; mean +/- sd) compared with control subjects (0.669 +/- 0.140 mm; P < 0.01). Univariate analysis showed a significant and inverse correlation between plasma APC-PCI levels and mean IMT (r = -0.32, P < 0.005), and multivariate regression analysis confirmed the independent correlation (P < 0.05). Moreover, plasma APC-PCI levels significantly and inversely correlated with plasma PDGF levels in diabetic patients (r = -0.30, P < 0.01). CONCLUSIONS: These results suggest that decreased APC generation is associated with vascular atherosclerotic changes in Type 2 diabetic patients.     

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.     

The level of 2-h post-challenge glucose is an independent risk factor of carotid intima-media thickness progression in Korean type 2 diabetic patients

OBJECTIVE: To evaluate the relationship between the metabolic abnormalities commonly associated with diabetes and the changes in carotid intima-media thickness (IMT) in Korean type 2 diabetic patients who do not have clinically manifest cardiovascular disease (CVD). DESIGN: In a prospective study, a total of 152 type 2 diabetic patients were recruited from a group of outpatients at the Yonsei University Hospital. MATERIALS AND METHODS: The carotid IMTs of 152 subjects with type 2 diabetes (mean age 63.5+/-7.0 years) were determined at baseline and after a mean follow-up time of 23.7+/-3.7 months. Fasting plasma glucose, serum total cholesterol (TC), serum triglyceride, high-density lipoprotein cholesterol (HDL-C), HbA1c, oral glucose tolerance test (OGTT) results for 2-h post-challenge glucose (2hPG), and blood pressure measurements were collected every 3 months and averaged. RESULTS: The highest quartiles of baseline C-peptide and homeostatic model assessment (HOMA) index showed more IMT progression than the lowest quartiles. The change in the mean IMT correlated with average values of HbA1c (r=.219, P=.007), the 2-h post-challenge glucose (r=.239, P=.003), HDL-C (r=-.228, P=.005), LDL-C (r=.175, P=.033), and non-HDL-C (r=.194, P=.016). Multiple regression analysis demonstrated that the independent risk factor for the mean IMT change in diabetic patients was the average 2hPG level (P=.004). The change in the mean IMT of those in the lowest quartile of average 2hPG (<11.1 mmol/l) was 823+/-176 to 841+/-146 microm (P=.276). In the highest quartile (2hPG >15.3 mmol/l), however, the mean IMT increased from 794+/-127 to 882+/-153 microm (P<.001). CONCLUSION: The 2hPG parameter among the various metabolic parameters exerts the greatest influence upon the prevention of carotid IMT progression in type 2 diabetic subjects. The level of 2hPG is an independent risk factor for the progression of carotid IMT in Korean type 2 diabetic patients.