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Stiffness Index (stiffness + index)
Selected AbstractsArterial stiffness in relation to subclinical atherosclerosisEUROPEAN JOURNAL OF CLINICAL INVESTIGATION, Issue 1 2009A. Wykretowicz ABSTRACT Background, Increased arterial stiffness or arteriosclerosis, represents a physiological part of ageing. Atherosclerosis is a process that does not affect the arterial bed uniformly but has a variable local distribution and is frequently superimposed on stiffened vessels. We therefore addressed the question of whether any correlation exists between the general characteristics of arterial stiffness or wave reflection and subclinical atherosclerosis as assessed by carotid intima-media thickness (IMT) in a sample of healthy subjects. Methods, A total of 116 healthy subjects (mean age 55 years, 43 female) were evaluated. Arterial stiffness and wave reflection was assessed with the use of digital volume pulse analysis (DVP) and pulse wave analysis (PWA). Subclinical atherosclerosis was assessed by measurement of IMT. Results, Stiffness Index (SIDVP), the measure of general arterial stiffness correlated significantly with IMT (r = 0·37, P < 0·01). IMT correlated significantly with age (r = 0·5, P < 0·0001), waist to hip ratio (WHR) (r = 0·39, P < 0·0001) and mean blood pressure (BPmean) (r = 0·4, P < 0·0001). IMT did not correlate with measures of wave reflection. SIDVP correlated significantly with age (r = 0·32, P < 0·005), WHR (r = 0·36, P < 0·0001), BPmean (r = 0·36, P < 0·0001) and measurements of wave reflection. However analysis of a model which included variables that significantly influenced SIDVP and IMT, such as age, WHR and mean BP showed that arterial stiffness is not independently associated with subclinical atherosclerosis. Conclusions, The indices of subclinical atherosclerosis, arterial stiffness and wave reflection, indicate different aspects of vascular status in otherwise healthy subjects [source] Aortic Upper Wall Tissue Doppler Image Velocity: Relation to Aortic Elasticity and Left Ventricular Diastolic FunctionECHOCARDIOGRAPHY, Issue 9 2009Soon Yong Suh M.D. Background: Aortic stiffening contributes to the left ventricular (LV) afterload, hypertrophy, and substrate for diastolic dysfunction. It is also known that aortic elastic properties could be investigated with color tissue Doppler imaging (TDI) in aortic upper wall. The purpose of this study is to evaluate the relation of aortic upper wall TDI and aortic stiffness and other parameters of LV diastolic function. Methods: We examined aortic upper wall by TDI at the 3 cm above the aortic valves because of patient's chest discomfort or dyspnea. We excluded the patient with arterial hypertension or reduced left ventricular ejection fraction (LVEF) or significant valvular heart disease. So a total of 126 (mean age 53.8 ± 13.9 years, male 49.2%) patients were enrolled in this study and divided normal LV filling group (N = 31) and abnormal LV filling group (N = 95). Results: Aortic upper wall early systolic velocity and late diastolic velocity were not different between the two groups. Only aortic upper wall early diastolic velocity (AWEDV) was related to aortic stiffness index (r =,0.25, P = 0.008), distensibility (r = 0.28, P = 0.003), early diastolic (Em) (r = 0.45, P = 0.001), E/Em (r =,0.26, P = 0.003), and significantly reduced in abnormal LV filling group (6.19 ± 2.50 vs 8.18 ± 2.87, P = 0.001). Conclusions: AWEDV is decreased significantly in abnormal LV filling patients. It is statistically related to aortic stiffness, distensibility and parameters of abnormal LV filling, Em, E/Em. TDI velocity of the aortic upper wall can be a helpful tool for evaluating aortic stiffness, distensibility, and diastolic function. [source] Assessment of Elastic Properties of the Descending Thoracic Aorta By Transesophageal Echocardiography with Acoustic Quantification in Patients with a StrokeECHOCARDIOGRAPHY, Issue 8 2000Seok-Min Kang M.D. Previous studies have described the use of transesophageal echocardiography (TEE) with acoustic quantification (AQ) in assessing aortic elastic properties. We hypothesized that patients with a prior history of stroke (ST) may have a higher risk of atherosclerotic change in great vessels compared to nonstroke subjects (NST) and thus have decreased elastic properties. We assessed the elastic properties of the descending thoracic aorta (DTA) by TEE in ST patients and compared them with data in NST patients. Subjects included 31 with ST without any evidence of emboli originating from the heart (age 51 ± 10 years, M: F = 20: 11) and 25 age-matched NST (M: F= 8: 17). Patients with significant valvular heart disease including aortic and mitral regurgitation, left ventricular dysfunction (ejection fraction < 55%), and congenital heart disease were excluded. Compliance (C), distensibility (D), and stiffness index (SI) were measured using AQ and M-mode measurement at a level of the left atrium. We scored atherosclerotic risk factors (ARF) such as a history of diabetes, hypertension, smoking, hypercholesterolemia, and the presence of atheroma of DTA. There was no evidence of atheroma of DTA in NST. There were no significant differences in heart rate and systolic and diastolic blood pressure between ST and NST patients. Fractional area change (FAC) of DTA was significantly lower in ST than in NST patients (3.2 ± 1.6 vs 5.4 ± 2.5%, P= 0.000). ST patients had significantly lower C (1.2 ± 0.4 vs 1.5 ± 0.7 times 10 -3 cm2 mmHg -1, P= 0.039), lower D (0.8 ± 0.3 vs 1.5 ± 0.8 times 10 -3 mmHg -1, P= 0.000), and higher SI (10.3 ± 8.8 vs 5.3 ± 2.9, P= 0.006) than NST patients. ST patients without atheroma of DTA (n± 21) also had significantly lower C (1.1 ± 0.4 vs 1.5 ±0.7 times 10 -3 cm -2 mmHg -1, P= 0.038) and lower D (3.5 ± 1.4 vs 4.8 ± 2.4 times 10 -3 mmHg -1, P= 0.021) than NST patients. There was a significant positive correlation between SI and the score of ARF (r= 0.51, P= 0.000). The regional elastic properties of DTA measured by TEE with AQ and M-mode method were abnormal in ST. Therefore, TEE with AQ technique may have a possible clinical application for the detection of early atherosclerotic changes such as alteration of elastic properties in morphological normal DTA. [source] Ultrasound parameters of bone health and related physical measurement indicators for the community-dwelling elderly in JapanGERIATRICS & GERONTOLOGY INTERNATIONAL, Issue 2 2007Wei Sun Deteriorated bone strength, which approaches osteoporosis, increases the likelihood that an elderly person will not able to live independently. However, few data are available pertaining to bone health and various physical objective indicators. The aim of the present study was to objectively assess bone health by quantitative ultrasound (QUS) and identify related physical measurement indicators among the elderly to aid the health promotion strategies in Japan. A cross-sectional study was performed at five welfare centers for the aged in the suburban area of Takatsuki city, Japan. Subjects comprised community-dwelling persons (134 men, 240 women) aged ,60 years and registered at welfare centers. QUS of the right-heel was conducted and recorded as stiffness index (SI). Physical factors including body components (fat and muscle mass), handgrip strength, daily physical activity, daily walking steps, maximum and usual walking speed and maximum bite force were examined objectively during the period May,June 2005. SI in women was lower than that in men (P < 0.01) and decreased significantly with age (P < 0.01). The SI correlated with six physical items in men and with all items in women. Multiple linear regression analysis showed that muscle mass, usual walking speed and maximum bite force were the strongest physical indicators of male SI; and muscle mass, maximum walking speed and maximum bite force were the strongest indicators of female SI. Muscle training, daily walking exercise and oral health care should be included in health promotion programs for the bone health of elderly women and men in Japan. [source] Low serum bilirubin concentrations are associated with impaired aortic elastic properties, but not impaired left ventricular diastolic functionINTERNATIONAL JOURNAL OF CLINICAL PRACTICE, Issue 2 2007M. Caliskan Summary Elevated serum bilirubin concentrations protect from atherosclerotic diseases; however, it is not clear whether higher serum bilirubin concentrations in physiological ranges do the same. To investigate the association of high and low serum bilirubin concentrations with left ventricular diastolic function and aortic elastic properties. We evaluated left ventricular diastolic function and aortic elastic properties of 42 healthy subjects with hypobilirubinemia (total bilirubin 0.40 ± 0.08 mg/dl; mean age 37.0 ± 3.9) and 40 healthy subjects with hyperbilirubinemia (total bilirubin 1.56 ± 0.49 mg/dl; mean age 36.2 ± 6.0) using transthoracic second harmonic Doppler echocardiography. Age, gender, body mass index and coronary risk factors were similar between the groups, except high-sensitivity C-reactive protein (hsCRP). Left ventricular diastolic parameters were similar between the two groups. Aortic distensibility (AoD) was found to be significantly lower (11.1 ± 3.9 vs. 13.2 ± 4.9, p = 0.03) and aortic stiffness index (AoSI) (1.99 ± 0.30 vs. 1.85 ± 0.26, p = 0.02) and elastic modulus (AoEM) (2.06 ± 0.83 vs. 1.73 ± 0.68, p = 0.03; the low and high bilirubin groups, respectively) higher in the low bilirubin group. Serum total bilirubin concentration correlated with hsCRP levels, AoD, AoSI and AoEM. In conclusion, left ventricular systolic and diastolic functions were similar between hypo- and hyperbilirubinemic subjects, but aortic elastic properties were impaired in subjects with lower serum bilirubin concentrations. [source] Association with replication between estrogen-related receptor , (ESRR,) Polymorphisms and bone phenotypes in women of European ancestryJOURNAL OF BONE AND MINERAL RESEARCH, Issue 4 2010Latifa Elfassihi Abstract Osteoporosis is a bone disease characterized by low bone mineral density (BMD), a highly heritable polygenic trait. Women are more prone than men to develop osteoporosis owing to a lower peak bone mass and accelerated bone loss at menopause. Lack of estrogen thus is a major risk factor for osteoporosis. In addition to having strong similarity to the estrogen receptor 1 (ESR1), the orphan nuclear estrogen-related receptor , (ESRR,) is widely expressed and shows overlap with ESR1 expression in tissues where estrogen has important physiologic functions. For these reasons, we have undertaken a study of ESRR, sequence variants in association with bone measurements [heel quantitative ultrasound (QUS) by measurements of broadband ultrasound attenuation (BUA), speed of sound (SOS), and stiffness index (SI) and dual-energy X-ray absorptiometry (DXA) at the femoral neck (FN) and lumbar spine (LS)]. A silent variant was found to be associated with multiple bone measurements (LS, BUA, SOS, and SI), the p values ranging from .006 to .04 in a sample of 5144 Quebec women. The region of this variant was analyzed using the HapMap database and the Gabriel method to define a block of 20,kb. Using the Tagger method, eight TagSNPs were identified and genotyped in a sample of 1335 women. Four of these SNPs capture the five major block haplotypes. One SNP (rs2818964) and one haplotype were significantly associated with multiple bone measures. All SNPs involved in the associations were analyzed in two other sample sets with significant results in the same direction. These results suggest involvement of ESRR, in the determination of bone density in women. © 2010 American Society for Bone and Mineral Research [source] Assessment of the 10-Year Probability of Osteoporotic Hip Fracture Combining Clinical Risk Factors and Heel Bone Ultrasound: The EPISEM Prospective Cohort of 12,958 Elderly Women,,JOURNAL OF BONE AND MINERAL RESEARCH, Issue 7 2008Didier Hans Abstract This study aimed to develop a hip screening tool that combines relevant clinical risk factors (CRFs) and quantitative ultrasound (QUS) at the heel to determine the 10-yr probability of hip fractures in elderly women. The EPISEM database, comprised of ,13,000 women ,70 yr of age, was derived from two population-based white European cohorts in France and Switzerland. All women had baseline data on CRFs and a baseline measurement of the stiffness index (SI) derived from QUS at the heel. Women were followed prospectively to identify incident fractures. Multivariate analysis was performed to determine the CRFs that contributed significantly to hip fracture risk, and these were used to generate a CRF score. Gradients of risk (GR; RR/SD change) and areas under receiver operating characteristic curves (AUC) were calculated for the CRF score, SI, and a score combining both. The 10-yr probability of hip fracture was computed for the combined model. Three hundred seven hip fractures were observed over a mean follow-up of 3.2 yr. In addition to SI, significant CRFs for hip fracture were body mass index (BMI), history of fracture, an impaired chair test, history of a recent fall, current cigarette smoking, and diabetes mellitus. The average GR for hip fracture was 2.10 per SD with the combined SI + CRF score compared with a GR of 1.77 with SI alone and of 1.52 with the CRF score alone. Thus, the use of CRFs enhanced the predictive value of SI alone. For example, in a woman 80 yr of age, the presence of two to four CRFs increased the probability of hip fracture from 16.9% to 26.6% and from 52.6% to 70.5% for SI Z-scores of +2 and ,3, respectively. The combined use of CRFs and QUS SI is a promising tool to assess hip fracture probability in elderly women, especially when access to DXA is limited. [source] The Association Between Heel Ultrasound and Hormone Replacement Therapy Is Modulated by a Two-Locus Vitamin D and Estrogen Receptor GenotypeJOURNAL OF BONE AND MINERAL RESEARCH, Issue 6 2000Yves Gigučre Abstract Evidence supports the role of estrogen deprivation in the process of bone remodeling and increased risk of fracture in postmenopausal women but little is known about the genetic basis of individual differences in response to therapy. In a cross-sectional study, 425 ambulatory postmenopausal French-Canadian women from Quebec (age range, 42,85 years old) were genotyped for a common Bsm I polymorphism at the vitamin D receptor (VDR) gene as well as a Pvu II polymorphism in the estrogen receptor (ESR1) gene. Heel ultrasound was determined by right calcaneal quantitative ultrasound (QUS) and results were expressed as an age- and-weight-adjusted stiffness index (heel SI z score). Our aim was to investigate the interaction between hormone-replacement therapy (HRT) and receptor genotypes in an effect on heel SI. Notably, a two-locus genotype (VDR-bb/ESR-PP) present in 9.5% of women was responsible for over 30% of the total HRT-related heel SI difference in the whole sample. Women bearing this combined VDR/ESR1 genotype who received HRT for more than 5 years had a 21% (1.25 SD) greater heel SI (p = 0.002) than those bearing the same genotype but who received HRT for <5 years. This may translate into a 2- to 3-fold difference in the risk of fracture. Although follow-up studies are needed, our findings suggest that QUS of the heel in postmenopausal women taking HRT is affected by variation in VDR and ESR1 loci, jointly. [source] Relationship of asymmetric dimethylarginine and homocysteine to vascular aging in systemic lupus erythematosus patientsARTHRITIS & RHEUMATISM, Issue 6 2010Michelle Perna Objective Systemic lupus erythematosus (SLE) is independently associated with accelerated atherosclerosis and premature arterial stiffening. Asymmetric dimethylarginine (ADMA) and homocysteine are mechanistically interrelated mediators of endothelial dysfunction and correlates of atherosclerosis in the general population. The aim of this study was to assess the relationship of ADMA and homocysteine to subclinical vascular disease in patients with SLE. Methods One hundred twenty-five patients with SLE who were participating in a study of cardiovascular disease underwent clinical and laboratory assessment, carotid artery ultrasonography to detect atherosclerosis, and radial artery applanation tonometry to measure arterial stiffness. Results Neither ADMA nor homocysteine correlated with the presence or extent of carotid atherosclerosis. In contrast, ADMA was significantly related to the arterial stiffness index. Independent correlates of arterial stiffening included the ADMA concentration, the presence of diabetes mellitus, older age at the time of diagnosis, longer disease duration, and the absence of anti-Sm or anti-RNP antibodies. A secondary multivariable analysis substituting homocysteine for ADMA demonstrated comparable relationships with arterial stiffness (r2 = 0.616 for homocysteine and r2 = 0.595 for ADMA). Conclusion ADMA and homocysteine are biomarkers for and may be mediators of premature arterial stiffening in patients with SLE. Because arterial stiffness has independent prognostic value for cardiovascular morbidity and mortality, its predictors may identify patients who are at increased risk of cardiovascular disease. [source] Do women with polycystic ovary syndrome really have predisposition to atherosclerosis?AUSTRALIAN AND NEW ZEALAND JOURNAL OF OBSTETRICS AND GYNAECOLOGY, Issue 2 2006Semra TOPCU Abstract The elastic properties of the aorta were studied in 28 women with polycystic ovary syndrome (PCOS) and in 26 regularly menstruating healthy women. In PCOS and control groups, systolic and diastolic blood pressure, aortic systolic diameter, aortic diastolic diameter, aortic distensibility, aortic stiffness index, and aortic elastic modulus were similar. It is likely that PCOS does not have any innate adverse effects on the cardiovascular system if its undesirable metabolic consequences are successfully controlled. [source] Enzymatic Treatment of Mechanical Pulp Fibers for Improving Papermaking PropertiesBIOTECHNOLOGY PROGRESS, Issue 6 2000Ken K. Y. Wong Three enzyme preparations (crude cellulase, laccase, and proteinase) were evaluated for their potential to improve the papermaking properties of mechanical pulp. After treating a long fibre-rich fraction of the pulp with enzyme, the fibres were recombined with untreated fines for handsheet making and testing. None of the enzymes altered the retention of fines or the consolidation of the furnish mix during handsheet formation. All three enzymes increased tensile stiffness index, which is a measure of the initial resistance of the handsheets to strain. Only the laccase preparation, an enzyme that modifies pulp lignin, consistently increased fibre bonding to enhance other strength properties of the handsheets. [source] Compliance properties of conduits used in vascular reconstruction,BRITISH JOURNAL OF SURGERY (NOW INCLUDES EUROPEAN JOURNAL OF SURGERY), Issue 11 2000N. R. Tai Background Compliance mismatch between native artery and prosthetic graft used for infrainguinal bypass is implicated in the aetiology of graft failure. The aim was to quantify the elastic properties of a new compliant poly(carbonate)polyurethane (CPU) vascular graft, and to compare the compliance properties of grafts made from CPU, expanded polytetrafluoroethylene (ePTFE), Dacron and human saphenous vein with that of human muscular artery. Methods A pulsatile flow phantom was used to perfuse vessel and prosthetic graft segments at physiological pulse pressure and flow. Intraluminal pressure was measured using a Millar Mikro-tip catheter transducer and vessel wall motion was determined with duplex ultrasonography using an echo-locked wall-tracking system. Diametrical compliance and a stiffness index were then calculated for each type of conduit over mean pressures ranging from 30 to 100 mmHg by 10-mmHg increments. Results The compliance values of CPU and artery (mean over the pressure range) were similar (mean(s.d.) 8·1(0·4) and 8·0(5·9) per cent per mmHg × 10,2 respectively), although the elastic behaviour of artery was anisotropic unlike CPU, which was isotropic. Dacron and ePTFE grafts had lower compliance values (1·8(1·2) and 1·2(0·3) per cent per mmHg × 10,2 respectively, averaged over the pressure range). In both these cases, compliance and stiffness differed significantly from that of artery over a mean pressure range of 30,90 mmHg. Human saphenous vein exhibited anisotropic behaviour and, although compliant at low pressure (30 mmHg), was markedly incompliant at higher pressures. Conclusion Compliant polyurethane grafts offer a greater degree of compliance match than either ePTFE or Dacron. © 2000 British Journal of Surgery Society Ltd [source] Endothelial progenitor cells and arterial functions in the late convalescence period of Kawasaki diseaseACTA PAEDIATRICA, Issue 8 2009Xiao-qin Liu Abstract Aim:, The relationship was investigated between endothelial progenitor cells (EPCs) level and arterial functions in the convalescence of Kawasaki disease (KD). Methods:, Sixty-three children were divided into coronary artery lesion (CAL) group (group 1, n = 21), non-CAL group (group 2, n = 20) and control group (group 3, n = 22). EPCs were examined by flow cytometry and arterial functions (flow-mediated dilation [FMD], carotid artery stiffness index [SI]) were measured by ultrasound. Results:, From group1 to group 3, FMD was 4.5%± 1.5%, 9.5%± 2.8% and 12.1%± 2.3% (p < 0.01 between any two groups); carotid artery SI was 4.10 ± 0.44, 3.81 ± 0.50 and 3.59 ± 0.46 (group 1 vs. group 2, p < 0.05; group 1 vs. group 3, p < 0.01; group 2 vs. group 3, p = 0.142) and the number of EPCs was 2.0 ± 0.6/,L, 4.2 ± 0.8/,L, 4.5 ± 0.7/,L (p < 0.01 for group1 vs. group 2 and group 1 vs. group 3; group 2 vs. group 3, p = 0.292). Multiple linear regressions analysis and correlation analysis identified that FMD and carotid artery SI were significant determinants of EPCs level and were all independently correlated with EPCs level. Conclusions:, Our results indicate decreased EPCs are associated with arterial dysfunction in patients with CAL in the convalescence of KD. Our findings suggest EPCs may have a role in alteration of arterial functions. [source] Increased arterial stiffness in children and adolescents with type 1 diabetes: no association between arterial stiffness and serum levels of adiponectinPEDIATRIC DIABETES, Issue 1 2010Angela Galler Galler A, Heitmann A, Siekmeyer W, Gelbrich G, Kapellen T, Kratzsch J, Kiess W. Increased arterial stiffness in children and adolescents with type 1 diabetes: no association between arterial stiffness and serum levels of adiponectin. Objective: Type 1 diabetes is associated with an increased risk of atherosclerosis. Adiponectin serum levels correlate inversely with cardiovascular disease in adults. The aim of this study was to examine associations between arterial stiffness indices and serum adiponectin concentrations in children and adolescents with type 1 diabetes and to study the impact of metabolic control. Subjects and methods: We evaluated arterial stiffness, distensibility, and compliance in 93 children and adolescents with type 1 diabetes and correlated the data with clinical parameters and HbA1c levels. The control group comprised 85 matched healthy children. Serum levels of adiponectin in children with diabetes were measured by enzyme-linked immunoassay and correlated with arterial stiffness indices. Results: Arterial stiffness was significantly increased in children and adolescents with type 1 diabetes (aged 13.0 ± 3.8 yr) compared with matched healthy children (p = 0.03). Arterial stiffness was elevated in males with type 1 diabetes compared with females (p = 0.023). Arterial distensibility was significantly lower in children with diabetes compared with healthy controls (p = 0.025). Arterial stiffness, distensibility, and compliance did not correlate with diabetes duration, level of HbA1c, or serum cholesterol. Adiponectin concentrations in children and adolescents with diabetes were significantly elevated compared with normal values based on gender, age, and body mass index. We found no significant associations between arterial stiffness indices and adiponectin levels in children with type 1 diabetes. Conclusions: Children and adolescents with type 1 diabetes had increased arterial stiffness and reduced arterial distensibility and arterial compliance. However, no associations between arterial functional alterations and adiponectin concentrations were seen. [source] | ||||||||||