Increase In Arterial Wall Thickness Research Articles

Impact of type 2 diabetes mellitus on hemodynamic and morphology of foot arteries: A duplex ultrasound evaluation

BackgroundType-2 Diabetes Mellitus (T2DM) is a significant health condition that is becoming more prevalent worldwide. Uncontrolled diabetes can lead to various complications, including peripheral artery disease (PAD). Duplex ultrasonography is critical to identify the stage of the disease and the patient's suitability for treatment procedures.Purpose: to assess Doppler blood flow parameters and morphologic alterations of dorsalis pedis artery (DPA) and posterior tibial artery (PTA) in T2DM. Materials and methodsA cross-sectional single-center study was conducted in Khartoum State. One hundred adult diabetic patients with average ankle-brachial index and reasonable glycemic control were selected randomly and enrolled in the study. Their age ranged from 27 to 86 years. A Duplex ultrasound examination was performed using a high-frequency ultrasound probe to assess the Doppler indices, arterial diameters, and wall thickness of the DPA and PTA. The data were analyzed using SPSS program version 23. ResultsIncreased duration of type-2 diabetes cause a significant increase in arterial wall thickness and pulsatility index (PI) of the DPA and PTA; (p-value < 0.05). The PI values decreased significantly in diabetic patients with trophic skin foot changes (p-value < 0.001), while the blood resistive index (RI) increased significantly in these patients (p-values < 0.01). Despite the reasonable glycemic control, a positive linear relationship was found between glycosylated hemoglobin (HA1c) levels and RI values of both DPA and PTA (R2 = 0.642). ConclusionThe study concluded that in type 2 diabetes with reasonable glycemic control, the arterial wall thickness of DPA and PTA increased as the duration of diabetes increased. The PI values of DPA and right PTA increased significantly with the increased time of the disease. The RI increased, and PI decreased in a subgroup with trophic skin changes. There is a positive linear relationship between glycosylated hemoglobin (HA1c) levels and RI values of both DPA and PTA.

MO086THE EFFECT OF HIGH SODIUM CHLORIDE INTAKE ON CARDIOVASCULAR SYSTEM AND KIDNEYS IN SPONTANEOUSLY HYPERTENSIVE RATS

Abstract Background and Aims It is believed that high consumption of sodium chloride (NaCl) leads to the development of arterial hypertension, which result in heart remodeling, however, NaCl can probably cause direct heart damage. We aimed to evaluate the effects of high and normal NaCl containing diets on blood pressure (BP), myocardial remodeling, as well as on the level of nuclear transcription factor κB (NFκB) expression in myocardium and kidneys. Method 49 spontaneously hypertensive rats (SHR) were enrolled and subdivided into 2 groups: Group 1 (n=24) received standard diet (NaCl=0,34%); Group 2 (n=25) was on high sodium diet (NaCl=8%). In 2 months, systolic BP, myocardial and renal mass indices, morphological changes, as well as NFκB expression in heart and kidneys were assessed. Results are presented as mean ± SD. Results BP in group 2 did not change significantly (190 ± 10 mm Hg, p&amp;gt; 0.05) compared to group 1, yet left ventricle muscle mass indices as well as, right and left kidney mass indices were higher. Hypertrophy of cardiomyocytes (CMC) was found in group2: (area of the nucleus- 43.55 ± 17.39 μm2 (p &amp;lt;0.001); area of CMC-21799.31 ± 579.89 μm2 (p &amp;lt;0.001), compared to group 1: (area of the nucleus- 36.14 ± 4.67 μm2 (p &amp;lt;0.001); area of CMC-19011.13 ± 571.8 μm2 (p &amp;lt;0.001). Also, perivascular fibrosis was found in group2 (area of perivascular connective tissue(APCT)- 4038.96 ± 28.58 μm2 (p &amp;lt;0.001), compared to group1 (APCT-3718.36 ± 91.8 μm2, p &amp;lt;0.001). An increase in arterial wall thickness was noted in group 2 (15.71 ± 6.28 μm, p&amp;lt;0,001), compared to group 1 (13.51 ± 8 ,68 μm, p&amp;lt;0,001). The expression level of NFκB in myocardial tissue (n = 7) in group 2 was 33 times higher, and in kidney tissue (n = 5) 12 times higher than in group 1 (n = 8). Conclusion High consumption of NaCl induces NFκB activation in kidneys and myocardium, and may cause myocardial remodeling, probably via NFκB - associated signaling pathways.

Emerging options for the treatment of type 2 diabetes in Chinese patients: focus on arterial function and alogliptin.

Type 2 diabetes mellitus (T2DM) has become a worldwide health problem, and the rate of it is growing greatly in the People’s Republic of China every year. T2DM could cause macrovascular and microvascular complications that lead to an increase in arterial wall thickness, endothelial dysfunction, calcification, and – finally – to an increase in arterial stiffness and arterial dysfunction. Alogliptin, a new selective inhibitor of dipeptidyl peptidase 4, has shown its great antihyperglycemia effect in T2DM patients. The clinical trial data from the People’s Republic of China was similar to other global and Asian trials. This could provide some choice for clinical physicians to the treatment of T2DM.

Low wall stress in the popliteal artery: Other mechanisms responsible for the predilection of aneurysmal dilatation?

The popliteal artery (PA) is, after aorta, the most common site for aneurysm formation. Why the PA is more susceptible than other peripheral muscular arteries is unknown. We hypothesized that the wall composition, which in turn affects wall properties, as well as the circumferential wall stress (WS) imposed on the arterial wall, might differ compared to other muscular arteries. The aim was to study the WS of the PA in healthy subjects with the adjacent, muscular, common femoral artery (CFA) as a comparison. Ninety-four healthy subjects were included in this study (45 males, aged 10-78 years and 49 females, aged 10-83 years). The diameter and intima-media thickness (IMT) in the PA and CFA were investigated with ultrasound. Together with blood pressure the WS was defined according to the law of Laplace adjusted for IMT. The diameter increased with age in both PA and CFA (p<0.001), with males having a larger diameter than females (p<0.001). IMT increased with age in both PA and CFA (p<0.001), with higher IMT values in males only in PA (p<0.001). The calculated WS was unchanged with age in both arteries, but lower in PA than in CFA in both sexes (p<0.001). In conclusion, this study shows that the PA and CFA WS is maintained during aging, probably due to a compensatory remodelling response with an increase in arterial wall thickness. However, the stress imposed on the PA wall is quite low, indicating that mechanisms other than WS contribute to the process of pathological arterial dilatation in the PA.

Functional arterial stiffness: The correlation between pulse volume and age in apparently healthy subjects

Background: Arterial wall thickness occurs with age in humans and is a strong predictor of cardiovascular disease risk. Age-related increase in arterial wall thickness is observed in the absence of atherosclerosis and hypertension. Measures of wall thickness are currently used as surrogates for and intermediate end points of atherosclerosis. Pulse volume refers to the movement of the vessel wall during the passage of the pulse wave and the stroke volume of the ventricles. The condition of the vessel wall affects the pulse volume. Therefore inthe present study we studied the changes in arterial pulse volume with age.Methods: The study was conducted on 40 volunteers from general population having no apparent disease. The subjects were divided into two groups: Group- I and Group-II. The Pulse Volume was recorded by Pulse Transducer and Student Physiograph (Inco Ambala, India). Normal arterial pulse was recorded and the rate, rhythm and average amplitude for one minute were calculated. Ratio of averaged Pulse Amplitude (PA) and Mean Arterial Pressure (MAP) of each subject was also calculated.Results: The mean age (years) of subjects in group-I was lower (19.301.25) as compared to group-II (61.605.91) (p< 0.001). The important finding of our study was the pulse amplitude (mm) (which represent the pulse volume) was significantly lower (7.241.36) in group II as compared to group I (19.106.87). We also calculated the ratio of Pulse amplitude and Mean Arterial which was significantly lower in group II as compared to group I.Conclusion: Our data suggests that the pulse transducer and physiograph can easily record the pulse volume index and asses the cardiovascular risk.

Impact of high-fat diet on antioxidant status, vascular wall thickening and cardiac function in adult female LDLR&amp;lt;sup&amp;gt;–/–&amp;lt;/sup&amp;gt; mice

Background: Western diet, rich in saturated fatty acids and cholesterol, is associated with increased cardiovascular risk. We thus investigated in female mice the influence of this diet on plasma antioxidant status, vascular wall thickening and cardiac function. Methods and Results: Adult female C57BL/6J wild type (WT) and LDLR–/– mice were fed a normal diet (ND) or a high-fat diet (HFD) for 17 weeks. HFD induced an increase in plasma lipids and vitamin C (Vit C) levels in both groups but at a much higher level in LDLR–/– and a decrease in plasma ascorbyl free radical levels to Vit C ratio (an endogenous oxidative stress index) in LDLR–/–. We only found a slight decrease in circulating antioxidant status evaluated by the Oxygen Radical Absorbance Capacity (ORAC) assay in WT, but not in LDLR–/–. Echocardiography evidenced an increase in arterial wall thickness in aortic arch at atherosclerosis predilection sites in HFD LDLR–/– as compared to ND LDLR–/– and HFD WT. This result was confirmed by histology. Further-more, histological examination of aortic valves showed an increase in atherosclerotic lesions. Our study, using echocardiography, show that chronic HFD does not induce any major modifications of systolic function in the both mice groups. Conclusions: High-fat intake in mice causes serious disturbances in lipid plasma levels associated to variations of circulating antioxidant status due, at least in part, to an increase in Vit C. At this stage, atherosclerotic lesions, observed in aortic arch and valve, do not impair cardiac function in HFD-fed mice.

Mechanisms of Cardiovascular Remodeling in Hyperhomocysteinemia

In hypertension, an increase in arterial wall thickness and loss of elasticity over time result in an increase in pulse wave velocity, a direct measure of arterial stiffness. This change is reflected in gradual fragmentation and loss of elastin fibers and accumulation of stiffer collagen fibers in the media that occurs independently of atherosclerosis. Similar results are seen with an elevated level of homocysteine (Hcy), known as hyperhomocysteinemia (HHcy), which increases vascular thickness, elastin fragmentation, and arterial blood pressure. Studies from our laboratory have demonstrated a decrease in elasticity and an increase in pulse wave velocity in HHcy cystathionine β synthase heterozygote knockout (CBS(-/+)) mice. Nitric oxide (NO) is a potential regulator of matrix metalloproteinase (MMP) activity in MMP-NO-TIMP (tissue inhibitor of metalloproteinase) inhibitory tertiary complex. We have demonstrated the contribution of the NO synthase (NOS) isoforms, endothelial NOS and inducible NOS, in the activation of latent MMP. The differential production of NO contributes to oxidative stress and increased oxidative/nitrative activation of MMP resulting in vascular remodeling in response to HHcy. The contribution of the NOS isoforms, endothelial and inducible in the collagen/elastin switch, has been demonstrated. We have showed that an increase in inducible NOS activity is a key contributor to HHcy-mediated collagen/elastin switch and resulting decline in aortic compliance. In addition, increased levels of Hcy compete and suppress the γ-amino butyric acid-receptor, N-methyl-d-aspartate-receptor, and peroxisome proliferator-activated receptor. The HHcy causes oxidative stress by generating nitrotyrosine, activating the latent MMPs and decreasing the endothelial NO concentration. The HHcy causes elastinolysis and decrease elastic complicance of the vessel wall. The treatment with γ-amino butyric acid-receptor agonist (muscimol), N-methyl-d-aspartate-receptor antagonist (MK-801), and peroxisome proliferator-activated receptor agonists (ciprofibrate and ciglitazone) mitigates the cardiovascular dysfunction in HHcy [corrected].

Protective Effect of Policosanol on Endothelium and Intimal Thickness Induced by Forceps in Rabbits

Policosanol is a cholesterol-lowering drug isolated from sugar cane wax with concomitant antiplatelet effects that prevents lipofundin-induced atherosclerotic lesions in rabbits and rats, including foam cell formation, and also reduces foam cell formation in carrageenan-induced granulomas in rats, while it inhibits proliferation of smooth muscle cells induced in rabbit cuffed artery. This study was undertaken to determine whether policosanol prevents endothelium damage and increase in arterial wall thickness in rabbits with arterial walls damaged with a forceps. Artery forceps were placed over the central artery of the right ear of all rabbits, and each artery was injured eight times. Animals were randomly distributed into four groups: a positive control group treated with Tween 20/H2O vehicle, two groups treated with policosanol (5 and 25 mg/kg, respectively), and a group treated with aspirin (8 mg/kg). Treatments were given for 30 days. Damaged arteries were examined by light and electron (transmission and scanning) microscopy. To evaluate intimal thickening, areas of intima were measured, and a significant reduction in policosanol-treated animals was observed. The endothelial surface, studied with scanning electron microscopy, revealed several types of damage. In control group, the endothelial surface was severely damaged. De-endothelialized areas were reduced in policosanol-treated animals. Platelet adhesion to subendothelium was seen in all animals of the control group, whereas policosanol-treated groups exhibited significantly reduced platelet adhesion. Policosanol also reduced, dose-dependently, the platelet sequestration induced in the damaged vessel wall, partially preventing the reduction in platelet count. It is concluded that policosanol prevents endothelium injury and reduces significantly intimal thickness of rabbit arteries damaged with forceps.

Cross-Sectional Association of Serum Phosphate With Carotid Intima-Medial Thickness in Hemodialysis Patients

Although an increased serum phosphate concentration is a significant risk factor for vascular calcification, it is unclear whether serum phosphate level is a risk factor for increased arterial wall thickness in hemodialysis patients. Using B-mode ultrasonography, we examined intima-medial thickness (IMT) of the carotid artery of hemodialysis patients and analyzed risk factors for increased IMT with regard to the effect of serum phosphate. Seven hundred sixteen hemodialysis patients were enrolled (547 patients without diabetes, 169 patients with diabetes; 441 men, 275 women; age, 60 +/- 8.5 years). IMT of patients with diabetes was significantly greater than that of patients without diabetes (0.859 +/- 0.250 versus 0.783 +/- 0.178 mm; P < 0.0001). For the group of all patients, IMT correlated weakly, but significantly, with serum phosphate level (r = 0.093; P = 0.0127). In multiple regression analysis of the group of all patients, greater serum phosphate level (beta = 0.166; P < 0.0001) was shown to be a significant independent risk factor for increased carotid IMT, in addition to other significant independent risk factors, including advanced age, higher blood pressure, greater non-high-density lipoprotein cholesterol level, and the presence of diabetes (R2 = 0.1119; P < 0.00001). In multiple regression analyses performed separately for hemodialysis patients without and with diabetes, greater phosphate level and advanced age were significant independent risk factors for increased IMT, independent of other confounding risk factors. These results show that in addition to advanced age, greater serum phosphate level is a significant and independent factor associated with advanced arteriosclerosis in hemodialysis patients with and without diabetes, suggesting that phosphate levels should be controlled appropriately to prevent an increase in arterial wall thickness in hemodialysis patients.

Cigarette smoking in military pilots and intima-media thickness of the carotid arteries

It is well known that smoking is associated with an increase in arterial wall thickness. However, most studies of this problem have been undertaken in age and sex heterogenous groups, as well as in patients with already present other conventional risk factors. The aim of this study was to assess the effect of cigarette smoking on arterial wall thickness of the common carotid artery in asymptomatic pilots. The imaging of intima-media thickness of the posterior wall of the distal 1 cm of both common carotid arteries was performed using a B mode ultrasound device, in 39 pilots (37.05 +/- 6.66 years), for whom smoking was the single cardiovascular risk factor. Comparisons were made with 49 non-smokers (35.12 +/- 7.39 years). The posterior walls of both common carotid arteries were thicker in smokers (left, p < 0.05; right, p > 0,05). Intima-media thickness was significantly lower on the right side than on the left side in both smokers and non-smokers (p < 0.01). Cigarette smoking as the single cardiovascular risk factor was associated with the wall thickness of the carotid arteries in our study. This finding indicated that early atherosclerosis was already present in pilots-smokers entering middle age.

Arterial remodelling in Fabry disease.

The enzymatic defect in Fabry disease results in the slow systemic deposition of uncleaved glycosphingolipids in the lysosomes of vascular endothelium and smooth muscle cells, leading to ischaemic strokes, cardiomyopathy and renal failure. Whereas it is known that Fabry disease affects small blood vessels, little is known about its effects on peripheral large arteries. We therefore set out to compare parameters of arterial wall structure and function in a cohort of patients with Fabry disease and an age-matched control group. Large artery phenotype was non-invasively investigated in 21 hemizygous patients with Fabry disease and 24 age-matched male controls. Common carotid and radial artery diameter, intima-media thickness (IMT) and distensibility were determined with high-definition echotracking systems and aplanation tonometry. Patients with Fabry disease had a significant twofold increase in radial artery IMT and distensibility, independent of body surface area, age and mean blood pressure. In both groups, older age at the time of examination was significantly associated with larger radial artery IMT. The relationship between age and radial IMT was 2.3-fold higher in patients with Fabry disease than in controls (p < 0.01). Carotid IMT was mildly but significantly increased in patients with Fabry disease (+18%), whereas distensibility was unchanged. This study presents evidence of a major increase in arterial wall thickness and distensibility, measurable at the site of a medium-sized artery, in a cohort of patients with classic Fabry disease.

Progression of large artery structural and functional alterations in Type I diabetes.

Type I (insulin-dependent) diabetes mellitus is accompanied by reduced arterial distensibility and increased arterial wall thickness even in normotensive subjects with no micro-macrovascular complications. It is not known whether, and how fast, these subclinical markers of vascular damage develop over time. We measured arterial wall distensibility in radial, common carotid artery and abdominal aorta in 60 normotensive patients (aged 35.0 +/- 1.2 years, means +/- SE) with Type I diabetes with no microvascular or macrovascular complications and in 20 healthy control subjects matched for age. Arterial distensibility was determined by continuous measurements of arterial diameter through echotracking techniques and by using either the Langewouters (radial artery) or the Reneman formula (carotid artery and aorta). The same echotracking techniques allowed us to ascertain the radial and carotid artery wall thickness. Data were collected before and after 23 +/- 1 months. In the first study, carotid artery distensibility was similar but radial artey and aortic distensibility was less (p < 0.01) in patients with diabetes than in control subjects (-39 % and 25 % respectively). This was accompanied by an increase (p < 0.01) in both radial (42 %) and carotid artery wall thickness (46 %). After 23 +/- 1 months diabetic subjects showed a further reduction in arterial distensibility (radial-12 %, p < 0.05; carotid-8 %, NS; aorta-20% p < 0.05) and an increase in arterial wall thickness (radial + 15 %; carotid 14%, p < 0,05). No change in distensibility and wall thickness values occurred in control subjects. The early reduction in arterial distensibility and increase in arterial wall thickness characterizing uncomplicated normotensive Type I diabetes patients shows a measurable worsening over the short term.

Intima–media thickness of peripheral arteries in asymptomatic cigarette smokers

Background and purpose: Although it is known that smoking is associated with an increase in arterial wall thickness, most studies have been performed in heterogeneous groups of older age, already suffering from atherosclerotic diseases or having additional cardiovascular risk factors. The purpose of this study is to assess the effect on arterial wall thickness of the carotid and femoral artery in cigarette smokers. Methods: In a cross-sectional study, intima–media thickness of the common and internal carotid artery, carotid bulb and common femoral artery was determined with the use of a B-mode ultrasound device, in 184 (44.3±9.0 years) cigarette smokers for whom smoking is the single cardiovascular risk factor. Comparisons were made with 56 non-smokers, matching in age and gender. Results: The posterior walls of both carotid bulbs (right: P=0.0005; left: P=0.02) and of the internal carotid arteries (right: P=0.004; left: P=0.003) as well as the posterior wall of the right common carotid artery ( P=0.02) and of the right common femoral artery ( P<0.0001) were thicker in smokers. Conclusions: Cigarette smoking as the single cardiovascular risk factor causes wall thickening of the carotid and femoral arteries, which indicates that early atherosclerosis is already present in smokers entering middle age.

Myosin isoform shifts and decreased reactivity in hypoxia-induced hypertensive pulmonary arterial muscle.

The principal stimulus that evokes pulmonary hypertension is chronic alveolar hypoxia. Pulmonary hypertension is associated with remodeling of the vessel walls, involving hypertrophy and hyperplasia of pulmonary arterial smooth muscle (PASM) and a concomitant increase in the deposition of connective tissue, resulting in increased wall thickness. The purpose of the present study was to determine the effect of hypoxia-induced hypertension on the structure and function of PASM. Experiments were designed to determine whether hypoxia-induced pulmonary hypertension is associated with alterations in PASM: 1) reactivity to a variety of agonists, 2) contractile protein proportions and isoforms, and 3) structural properties. Young adult male rats were made hypoxic by lowering the fraction of inspired O2 (10%) for 14 days. Pulmonary arterial segments were isolated and dose-response curves to various agonists (high K+, norepinephrine, serotonin, angiotensin II, and adenosine) were generated. Gel electrophoresis was used to measure changes in the relative amounts of actin or myosin and of myosin heavy chain (MHC) isoforms. Structural changes were correlated with the pharmacological and biochemical data. Hypoxia-induced pulmonary hypertension caused a general decreased reactivity, an increase in the proportion of nonmuscle to muscle MHC isoforms in PASM, and an increase in arterial wall thickness with PASM hypertrophy or hyperplasia.

Non-invasive measurements of arterial compliance in hypertensive compared with normotensive adults

To determine differences in arterial compliance attributable to hypertension. Since measurements of arterial compliance have tended to vary in the past according to the method used, a new technique comprising carotid ultrasound and simultaneous, calibrated, carotid pressure waveform measurements was tested in 43 hypertensives and 43 control subjects matched for age, gender and body size. There was a significant reduction in compliance among the hypertensive patients, as estimated by the elastic modulus and the ratio of stroke volume to pulse pressure. However, when the non-linearity of the pressure-volume relationship and the impact of distending pressure were taken into account, by the arterial stiffness index and by the increase in arterial wall thickness associated with hypertension by Young's modulus, there were no significant differences in arterial compliance between the two groups.

Effect of age on arterial distensibility in Asymptomatic humans.

This report describes a noninvasive method by which the volume distensibility of forearm arteries can be calculated from direct measurements of pulse wave velocity. Such measurements are made at a variety of transmural arterial pressures (TMP) accomplished by placing the forearm in a cylinder and changing the pressures within. This technique eliminates arterial blood pressure as a variable, which strongly influences arterial distensibility. We studied 48 asymptomatic men and women, ages 21 to 98 years. There was considerable scatter, but significant positive relationships were demonstrated between increasing arterial distensibility and age at ambient and lower TMPs. This finding can be explained by an age-related reduction in arterial luminal diameter and an increase in arterial wall thickness which reduces arterial wall tension and more than offsets the increased stiffness produced by changes in wall composition. In six subjects, pulse tracings were simultaneously recorded on paper and analog tape. The taped curves were digitized and subjected to Fourier analysis to determine the wave velocity of individual harmonics. The characteristic wave velocity was defined and found comparable to the hand method used in the same beats (regression coefficient = + 0.97). These data indicate that the automatic and manual methods measured the same variable.