Correlation between brachial-ankle pulse wave velocity and arterial compliance and cardiovascular risk factors in elderly patients with arteriosclerosis

Intensive blood pressure control on arterial stiffness among older patients with hypertension

BACKGROUND

Arterial stiffening increases with age and blood pressure and is associated with cardiovascular disease (CVD), but the relationship between blood pressure lowering and arterial stiffening is still uncertain, especially in older people. This study aimed to evaluate the effect of intensive blood pressure treatment on the progression of arterial stiffness and risk of CVD in older patients with hypertension.

METHODS

The Strategy of Blood Pressure Intervention in the Elderly Hypertensive Patients (STEP) trial was a multicenter, randomized, controlled trial performed at 42 clinical centers throughout China, and 8511 patients aged 60-80 years with essential hypertension were enrolled and randomly assigned to systolic blood pressure (SBP) target of 110 mmHg to <130 mmHg (intensive treatment) or 130 mmHg to <150 mmHg (standard treatment). Patients underwent repeated examinations of the brachial-ankle pulse wave velocity (baPWV) and ankle-brachial index (ABI) at baseline, and the arterial stiffness was evaluated at the 3-year follow-up. A total of 5339 patients who had twice repeated measurements were included in this study. Changes in arterial stiffness between the intensive and standard treatment groups were analyzed using a multivariate linear regression model. The Cox proportional hazard regression model was used to evaluate the effect of intensive treatment on primary CVD outcomes.

RESULTS

The changes in baPWV were 61.5 cm/s (95% confidence interval [CI]: 49.8-73.2 cm/s) in the intensive treatment group and 98.4 cm/s (95% CI: 86.7-110.1 cm/s) in the standard treatment group ( P <0.001). Intensive treatment significantly delayed the progression of arterial stiffness, with an annual change of 23.1 cm·s -1 ·year -1vs. 36.7 cm·s -1 ·year -1 of baPWV in the intensive and standard treatment groups, respectively. During a median follow-up period of 3.36 years, primary CVD outcomes occurred in 77 (2.9%) patients in the intensive treatment group compared with 93 (3.5%) in the standard treatment group. Intensive treatment resulted in a significantly lower CVD risk in patients aged 70-80 years or with SBP <140 mmHg.

CONCLUSION

Intensive blood pressure control with an SBP target of 110 mmHg to <130 mmHg could delay the progression of arterial stiffness and reduce the risk of CVD in older patients with hypertension.

CLINICAL TRIAL REGISTRATION

http://www.clinicaltrials.gov ; No. NCT03015311.

Comparison of arterial stiffness indices measured by pulse wave velocity and pulse wave analysis for predicting cardiovascular and all-cause mortality in a Chinese population

Arterial stiffness measured by pulse wave velocity and pulse wave analysis has been widely studied in different populations in terms of its correlation with cardiovascular events and all-cause mortality. It remains unknown which arterial stiffness index is better for risk stratification in the general population. We included 4129 participants from Gaoyou County, Jiangsu Province, China, with a median follow-up of 11 years. The primary endpoint was cardiovascular mortality, and the secondary endpoint was all-cause mortality. Harrell's C-index, net reclassification improvement (NRI) and integrated discrimination improvement (IDI) based on the Cox proportional hazards regression model were evaluated to assess predictive discrimination and accuracy. The associations between the 4 indices and cardiovascular mortality remained significant after adjusting for the Framingham Risk Score (FRS) and/or associated risk factors. Considering reclassification based on the newly integrated models (FRS model combined with the 4 indices), NRI for cardiovascular mortality showed that haPWV and baPWV had more significant improvement in reclassification compared with C1 and C2 [NRI with 95% CI: haPWV 0.410 (0.293, 0.523); baPWV 0.447 (0.330, 0.553); C1 0.312 (0.182, 0.454); C2 0.328 (0.159, 0.463); all P < 0.05]. This study showed that pulse wave velocity (haPWV and baPWV) provides better discrimination of long-term risk than arterial elasticity indices (C1 and C2) in the general population.

Post-Load Insulin Secretion Patterns are Associated with Glycemic Status and Diabetic Complications in Patients with Type 2 Diabetes Mellitus

BACKGROUND

To examine whether the different patterns of post-load insulin secretion can identify the heterogeneity of type 2 diabetes mellitus (T2DM).

METHODS

Six hundred twenty-five inpatients with T2DM at Jining No. 1 People's Hospital were recruited from January 2019 to October 2021. The 140 g steamed bread meal test (SBMT) was conducted on patients with T2DM, and glucose, insulin, and C-peptide levels were recorded at 0, 60, 120, and 180 min. To avoid the effect of exogenous insulin, patients were categorized into three different classes by latent class trajectory analysis based on the post-load secretion patterns of C-peptide. The difference in short- and long-term glycemic status and prevalence of complications distributed among the three classes were compared by multiple linear regression and multiple logistic regression, respectively.

RESULTS

There were significant differences in long-term glycemic status (e. g., HbA1c) and short-term glycemic status (e. g., mean blood glucose, time in range) among the three classes. The difference in short-term glycemic status was similar in terms of the whole day, daytime, and nighttime. The prevalence of severe diabetic retinopathy and atherosclerosis showed a decreasing trend among the three classes.

CONCLUSIONS

The post-load insulin secretion patterns could well identify the heterogeneity of patients with T2DM in short- and long-term glycemic status and prevalence of complications, providing recommendations for the timely adjustment in treatment regimes of patients with T2DM and promotion of personalized treatment.

A robust local pulse wave imaging method based on digital image processing techniques

The original diameter velocity loop method (ln(D)U-loop) cannot accurately extract the blood vessel diameter waveform when the quality of ultrasound image data is not high (such as obesity, age, and the operation of the ultrasound doctor), so it is unable to measure the pulse wave velocity (PWV) of the ascending aorta. This study proposes a diameter waveform extraction method combining threshold, gradient filtering, and the center of gravity method. At the same time, the linear regression method of searching for the rising point of the systolic period is replaced by the optimal average of two linear regression methods. This method can also extract the diameter waveform with poor-quality images and obtain a more accurate PWV. In vivo experimental data from 17 (age 60.5 ± 9.2) elderly patients with cerebral infarction and 12 (age 32.5 ± 5.6) healthy young adults were used for processing, and the results showed that the mean PWV using the ln(D)U-loop method was 12.56 (SD = 3.47) ms-1 for patients with cerebral infarction and 6.81 (SD = 1.73) ms-1 for healthy young adults. The PWV results based on the Wilcoxon rank-sum test and calculated based on the improved ln(D)U-loop method were both statistically significant (p < 0.01). The agreement analysis (Bland-Altman analysis) between the QA-loop and ln(D)U-loop methods showed that the mean deviation of the measured PWV was 0.07 m/s and the standard deviation of the deviation was 1.18 m/s. The experimental results demonstrated the effectiveness of the improved ln(D)U-loop method proposed in this paper on poor-quality images. This study can improve the possibility of the ln(D)U-loop method being widely used in the clinical measurement of ascending aortic PWV.

Time in range, assessed with continuous glucose monitoring, is associated with brachial-ankle pulse wave velocity in type 2 diabetes: A retrospective single-center analysis

AIMS

The aim of this retrospective single-center is to research the relationship between time in range(TIR), an important novel metric of glycemic control, assessed with continuous glucose monitoring(CGM) and brachial-ankle pulse wave velocity(BaPWV), a unique index of systemic arterial stiffness in type 2 diabetes.

METHODS

Study participants included 469 hospitalized patients with type 2 diabetes and no history of serious cardiovascular disease who underwent CGM and BaPWV measurements. TIR of 3.9-10.0 mmol/L was evaluated with CGM. BaPWV was measured by non-invasive arteriosclerosis detector and high baPWV was defined as a mean baPWV≧1800m/s. The spearman correlation and the partial correlation analysis were applied to analyze the correlation between TIR and baPWV. The binary logistic regression was used to examine the independent association of TIR and high BaPWV.

RESULTS

The presence of high baPWV was 32.2%. Compared with patients of low baPWV, those with high baPWV had significantly reduced TIR(P<0.001). With the increase of TIR tertiles, the prevalence of high BaPWV progressively decreased. Correlation analysis showed that TIR is inversely correlated with BaPWV. In a fully adjusted model controlling for traditional risk factor of CVD, TIR is associated with the presence of high BaPWV independent of HbA1c.

CONCLUSION

TIR is correlated with BaPWV independent of HbA1c in patients with type 2 diabetes, confirming a link between TIR and arterial stiffness.

Effects of Different Types of Carbohydrates on Arterial Stiffness: A Comparison of Isomaltulose and Sucrose

Increased arterial stiffness during acute hyperglycemia is a risk factor for cardiovascular disease, but the type of carbohydrate that inhibits it is unknown. The purpose of this study was to determine the efficacy of low-glycemic-index isomaltulose on arterial stiffness during hyperglycemia in middle-aged and older adults. Ten healthy middle-aged and older adult subjects orally ingested a solution containing 25 g of isomaltulose (ISI trial) and sucrose (SSI trial) in a crossover study. In the SSI trial, the brachial-ankle (ba) pulse wave velocity (PWV) increased 30, 60, and 90 min after ingestion compared with that before ingestion (p < 0.01); however, in the ISI trial, the baPWV did not change after ingestion compared with that before ingestion. Blood glucose levels 30 min after intake were lower in the ISI trial than in the SSI trial (p < 0.01). The baPWV and systolic blood pressure were positively correlated 90 min after isomaltulose and sucrose ingestion (r = 0.640, p < 0.05). These results indicate that isomaltulose intake inhibits an acute increase in arterial stiffness. The results of the present study may have significant clinical implications on the implementation of dietary programs for middle-aged and elderly patients.

Early arteriosclerosis and its risk factors in subjects with prediabetes and new-onset diabetes

BACKGROUND

We aimed to investigate early arteriosclerosis and its risk factors in populations with prediabetes and new-onset diabetes.

MATERIALS AND METHODS

A total of 148 participants who did not have diabetes mellitus were assigned to three groups through an oral glucose tolerance test: the normal glucose tolerance (NGT) group; the impaired glucose regulation, also known as prediabetes group and the new-onset type 2 diabetes mellitus group. The insulin resistance index was assessed using the homeostatic model assessment of insulin resistance (HOMA-IR). An ELISA was used to determine the level of fibroblast growth factor 21 (FGF21). An arteriosclerosis detector was used to measure the brachial-ankle pulse wave velocity (baPWV) and ankle-brachial index (ABI). The baPWV, ABI, and FGF21 were used to assess early arteriosclerosis.

RESULTS

Significant differences in age, systolic blood pressure (SBP), fasting plasma glucose (FPG), 2-h plasma glucose (2hPG), 2-h insulin (2hINS), and HOMA-IR were found between the NGT group and the prediabetes and new-onset diabetes groups. All of the above, except 2hINS, showed an increasing trend. Moreover, the FGF21 was higher in the new-onset diabetes group than in the NGT group. The baPWV was higher in the new-onset diabetes group than in the other two groups, but no significant difference was noted in the ABI. Age, SBP, diastolic blood pressure, FPG, 2hPG, and FGF21 were positively correlated with the baPWV. In addition, FPG, SBP, FGF21, and HOMA-IR were independent risk factors for the baPWV.

CONCLUSIONS

Patients with prediabetes and new-onset diabetes may have more significant early arteriosclerosis. The blood glucose level and insulin resistance index may be independent risk factors for early arteriosclerosis.

Associations between acute exposure to ambient air pollution and length of stay for inpatients with ischemic heart disease: a multi-city analysis in central China

Ambient air pollution (AAP) has been widely associated with increased morbidity of ischemic heart disease (IHD). However, no prior studies have investigated the effects of AAP exposure on the length of stay (LOS) due to IHD. Hospital data during 2015-2017 were obtained from hospital information system in five cities of Hubei province, China. We collected daily mean concentrations of air pollutants, including PM_2.5, PM₁₀, SO₂, NO₂, O₃, and CO, and meteorological data during the same time period. Poisson regression was applied to estimate the acute impacts of AAP on the LOS of IHD inpatients. A total of 42,114 inpatients with primary diagnosis of IHD were included, 50.63% of which were chronic IHD inpatients. Annual average concentrations of PM_2.5, PM₁₀, SO₂, NO₂, O₃, and CO were 61.93 μg/m³, 95.47 μg/m³, 18.59 μg/m³, 35.87 μg/m³, 100.30 μg/m³, and 1.117 mg/m³, respectively. After adjusting for temperature, relative humidity, gender, age group, payment method, number of hospital beds, location of hospital, and surgery or not, exposures to PM_2.5, PM₁₀, SO₂, O₃, and CO were associated with increased LOS for all IHD patients in both single- and multi-pollutant models, and stronger associations were observed among chronic IHD patients. In addition, subgroup analyses demonstrated that males and the group aged 65+ years were more vulnerable to air pollution, and the adverse effects were also promoted by low temperature in cold season. This study provides the first investigation of the adverse effects of AAP on the LOS for IHD patients. In order to shorten the LOS of IHD, measures should be taken to strengthen the AAP management and protect the high-risk population.

Ozone exposure is associated with acute changes in inflammation, fibrinolysis, and endothelial cell function in coronary artery disease patients

BACKGROUND

Air pollution is a major risk factor for cardiovascular disease, of which ozone is a major contributor. Several studies have found associations between ozone and cardiovascular morbidity, but the results have been inconclusive. We investigated associations between ozone and changes across biological pathways associated with cardiovascular disease.

METHODS

Using a panel study design, 13 participants with coronary artery disease were assessed for markers of systemic inflammation, heart rate variability and repolarization, lipids, blood pressure, and endothelial function. Daily measurements of ozone and particulate matter (PM2.5) were obtained from central monitoring stations. Single (ozone) and two-pollutant (ozone and PM2.5) models were used to assess percent changes in measurements per interquartile ranges of pollutants.

RESULTS

Per interquartile increase in ozone, changes in tissue plasminogen factor (6.6%, 95% confidence intervals (CI) = 0.4, 13.2), plasminogen activator inhibitor-1 (40.5%, 95% CI = 8.7, 81.6), neutrophils (8.7% 95% CI = 1.5, 16.4), monocytes (10.2%, 95% CI = 1.0, 20.1), interleukin-6 (15.9%, 95% CI = 3.6, 29.6), large-artery elasticity index (-19.5%, 95% CI = -34.0, -1.7), and the baseline diameter of the brachial artery (-2.5%, 95% CI = -5.0, 0.1) were observed. These associations were robust in the two-pollutant model.

CONCLUSIONS

We observed alterations across several pathways associated with cardiovascular disease in 13 coronary artery disease patients following ozone exposures, independent of PM2.5. The results support the biological plausibility of ozone-induced cardiovascular effects. The effects were found at concentrations below the EPA National Ambient Air Quality Standards for both ozone and PM2.5.

Low serum adiponectin level is associated with metabolic syndrome and is an independent marker of peripheral arterial stiffness in hypertensive patients

BACKGROUND

Adiponectin has been implicated in metabolic syndrome (MetS) and arterial stiffness (AS). We aim to determine the relationship between serum adiponectin concentration as well as peripheral AS in hypertensive patients.

METHODS

Fasting blood samples were obtained from 101 hypertensive patients. Brachial-ankle pulse wave velocity (baPWV) was measured with an automatic pulse wave analyzer. Serum adiponectin concentrations were determined by using an enzyme immunoassay kit. A baPWV >14.0 m/s was defined as high AS.

RESULTS

MetS and high AS were present in 62.4 and 71.3% of the study population. Adiponectin was inversely associated with MetS and high AS (both P < 0.001). Serum higher high-density lipoprotein cholesterol (HDL-C) (P = 0.012), triglycerides (P = 0.001), C-reactive protein (P < 0.001), insulin (P = 0.027), body weight (P = 0.002), waist circumference (WC, P < 0.001), body mass index (P = 0.001) bilateral-baPWV (P < 0.001), systolic blood pressure (SBP, P < 0.001), diastolic blood pressure (DBP, P = 0.012), pulse pressure (P = 0.019), homeostasis model assessment of insulin resistance (HOMA1-IR (P = 0.026) and HOMA2-IR (P = 0.020)) and lower glomerular filtration rate (GFR, P = 0.029) were significantly associated with high AS. Multivariate logistic regression analysis of the factors significantly associated with AS revealed that adiponectin [odds ratio: 0.932, 95% confidence interval (CI) 0.881-0.985, P = 0.012], and SBP (odds ratio: 1.059, 95% CI 1.008-1.113, P = 0.022) were the independent predictors of arterial stiffness in hypertensive patients. Subgroup analysis revealed that SBP (odds ratio: 1.126, 95% CI 1.024-1.237, P = 0.014) and GFR (odds ratio: 0.858, 95% CI 0.739-0.996, P = 0.043) were the independent predictors of arterial stiffness in hypertensive patients without MetS; adiponectin (odds ratio: 0.909, 95% CI 0.931-0.996, P = 0.040) was the independent predictor of arterial stiffness in hypertensive patients with MetS.

CONCLUSIONS

Hypoadiponectinemia has positive association with MetS and peripheral AS in hypertensive patients.

Ankle to brachial systolic pressure index at rest increases with age in asymptomatic physically active participants

BACKGROUND

It is commonly acknowledged that the ability to use the ankle-brachial index (ABI), a reliable way to diagnose atherosclerosis, decreases with age in the general population. The aim of this study was to determine the relationship between resting ABI and age in different populations.

METHODS

674 physically active participants with (active high risk, ACT_HR) or without (active low risk, ACT_LR) cardiovascular risk factors or/and sedentary (SED) subjects, aged 20-70 years. Systolic arterial pressure was recorded at rest and simultaneously with automatic sphygmomanometers at the arms and ankles. ABI was calculated as the ratio of the lowest, highest or mean ankle pressure to the highest arm pressure.

RESULTS

Proportion of ABI_min<0.90 was 10.3% in SED_HR subjects versus 0.5% and 1.2%, respectively, in ACT_HR and ACT_LR groups. The averaged ABI value of each group was in the normal range in all groups (ABI>0.90) but was significantly lower in SED_HR compared with all active participants (p<0.001). Regression lines from ABI_mean versus age could lead to approximately +0.05 every 15 years of age in apparently healthy active participants (ACT_LR).

CONCLUSION

ABI at rest increases with the increase in age in the groups of low-risk asymptomatic middle-aged trained adults. The previously reported decrease in ABI with age is found only in SED_HR subjects, and is very likely to rely on the increased prevalence of asymptomatic arterial disease in this group. The increase of ABI with age is consistent with the 'physiological' stiffness observed in ageing arteries even in the absence of 'pathological' atherosclerotic lesions.

TRIAL REGISTRATION NUMBER

NIH clinicaltrial.gov: NCT01812343.

Microparticles (CD146) and Arterial Stiffness Versus Carotid Intima Media Thickness as an Early Predictors of Vascular Affection in Systemic Lupus Patients

Objectives

This study aims to evaluate cluster of differentiation 146 (CD146) and pulse wave velocity (PWV) as non-invasive methods for prediction of early vascular affection in systemic lupus erythematosus (SLE) patients without symptoms of vascular disease, to detect the outcome and reproducibility of these methods, and to correlate CD146 and PWV with lipid profile, intima media thickness (IMT), and ankle brachial index.

Patients and methods

Thirty female SLE patients (mean age 26.6±6.6 years; range 15 to 35 years) fulfilling the American College of Rheumatology 1997 revised criteria for SLE classification, and 15 age and sex matched healthy controls were included. All participants were performed full clinical assessments including measurement of Systemic Lupus Erythematosus Disease Activity Index, lipid profile, CD146, carotid IMT, PWV, and rise time as an indication of how fast the waveform rises.

Results

Cluster of differentiation 146 levels were elevated in patients with SLE compared to controls (p<0.001). There was a statistically significant difference between patients and controls in the femoral, lower thigh, and ankle rise time. There was a statistically significant correlation between IMT and ages of patients, Systemic Lupus Erythematosus Disease Activity Index, and brachial-below knee PWV, while there was no correlation between IMT and disease duration, lipid profile, brachial-femoral PWV, and brachial-ankle PWV. There was statistically significant correlations between brachial-femoral PWV and serum cholesterol level, and between brachial-ankle PWV and low density lipoprotein cholesterol.

Conclusion

Our results showed that SLE vascular affection is more pronounced in small arteries. Also, elevated CD146 and brachial-femoral PWV are useful early markers of vascular affection in SLE as well as rise time may be a marker for arterial stiffness.

Pulse transit time measured by photoplethysmography improves the accuracy of heart rate as a surrogate measure of cardiac output, stroke volume and oxygen uptake in response to graded exercise

Heart rate (HR) is a valuable and widespread measure for physical training programs, although its description of conditioning is limited to the cardiac response to exercise. More comprehensive measures of exercise adaptation include cardiac output (Q̇), stroke volume (SV) and oxygen uptake (V̇O2), but these physiological parameters can be measured only with cumbersome equipment installed in clinical settings. In this work, we explore the ability of pulse transit time (PTT) to represent a valuable pairing with HR for indirectly estimating Q̇, SV and V̇O2 non-invasively. PTT was measured as the time interval between the peak of the electrocardiographic (ECG) R-wave and the onset of the photoplethysmography (PPG) waveform at the periphery (i.e. fingertip) with a portable sensor. Fifteen healthy young subjects underwent a graded incremental cycling protocol after which HR and PTT were correlated with Q̇, SV and V̇O2 using linear mixed models. The addition of PTT significantly improved the modeling of Q̇, SV and V̇O2 at the individual level ([Formula: see text] for SV, 0.548 for Q̇, and 0.771 for V̇O2) compared to predictive models based solely on HR ([Formula: see text] for SV, 0.503 for Q̇, and 0.745 for V̇O2). While challenges in sensitivity and artifact rejection exist, combining PTT with HR holds potential for development of novel wearable sensors that provide exercise assessment largely superior to HR monitors.

Relationship between sum of the four limbs' pulse pressure and brachial-ankle pulse wave velocity and atherosclerosis risk factors in Chinese adults

The aim of the present study was to analyze the relationship between the sum of the four limbs' pulse pressure (Sum-PP) and brachial-ankle pulse wave velocity (baPWV) and atherosclerosis risk factors and evaluate the feasibility of Sum-PP in diagnosing atherosclerosis systemically. For the purpose, a cross-sectional study was conducted on the basis of medical information of 20748 adults who had a health examination in our hospital. Both Sum-PP and baPWV exhibited significant variations among different human populations grouped by gender, smoking, drinking, and age. Interestingly, Sum-PP had similar varying tendency with baPWV in different populations. And further study in different populations showed that Sum-PP was significantly positively related to baPWV. We also investigated the relationship between Sum-PP, baPWV, and cardiovascular risk factors, respectively. We found that both Sum-PP and baPWV had significant positive correlation with atherosclerosis risk factors while both of them were negatively related to HDL-c. In addition, there was a significant close correlation between Sum-PP and baPWV in the whole population (r = 0.4616, P < 0.0001). Thus, Sum-PP is closely related to baPWV and is of important value for clinical diagnosis of atherosclerosis.

Arterial compliance across the spectrum of ankle-brachial index: the Multiethnic Study of Atherosclerosis

OBJECTIVE

A low ankle-brachial index is associated with cardiovascular disease and reduced arterial compliance. A high ankle-brachial index is also associated with an increased risk of cardiovascular events. We tested the hypothesis that subjects with a high ankle-brachial index demonstrate a lower arterial compliance. In addition, we assessed whether pulse pressure amplification is increased among subjects with a high ankle-brachial index.

METHODS

We studied 6814 adults enrolled in the Multiethnic Study of Atherosclerosis who were, by definition, free of clinical cardiovascular disease at baseline. Differences in total arterial compliance (ratio of stroke volume to pulse pressure), aortic and carotid distensibility (measured with magnetic resonance imaging and duplex ultrasound, respectively) were compared across ankle-brachial index subclasses (≤0.90, 0.91-1.29; ≥1.30) with analyses adjusted for cardiovascular risk factors and subclinical atherosclerosis.

RESULTS

Peripheral arterial disease was detected in 230 (3.4%) and high ABI in 648 (9.6%) of subjects. Those with high ankle-brachial index demonstrated greater aortic/radial pulse pressure amplification than those with a normal ankle-brachial index. In adjusted models aortic and carotid distensibility as well as total arterial compliance, were lowest among those with ankle-brachial index≤0.9 (p<0.01 vs. all), but were not reduced in subjects with an ankle-brachial index≥1.3.

CONCLUSION

Lower aortic, carotid and total arterial compliance is not present in subjects free of overt cardiovascular disease and with a high ankle-brachial index. However, increased pulse pressure amplification contributes to a greater ankle-brachial index in the general population and may allow better characterization of individuals with this phenotype.

Correlation between Proximal Abdominal Aortic Stiffness Measured by Ultrasound and Brachial-Ankle Pulse Wave Velocity

Background and Objectives

The proximal portion of the abdominal aorta (AA) is characterized by minimal arteriosclerosis compared with other aortic segments. To assess the clinical usefulness of this characteristic, the correlation between ultrasonographically measured proximal AA stiffness and brachial-ankle pulse wave velocity (baPWV) was examined.

Subjects and Methods

285 subjects were analyzed, half with hypertension and half with normal blood pressure. Proximal AA was examined using ultrasonography; strain, distensibility, elastic modulus, and the stiffness index were determined. After adjustment for age, gender, body mass index (BMI), systolic blood pressure (SBP), and heart rate, the relationships between baPWV and all these parameters were tested.

Results

The mean age of the study subjects was 58.1±12.8 years and the mean BMI was 24.3±3.8 kg/cm². 58.9% of the subjects were female. 42.8% were hypertensive subjects. Among the hypertensive subjects, 56.0% were taking antihypertensive medication. Adjusted partial correlation coefficients for the relationship between baPWV with strain, distensibility, elastic modulus, and the stiffness index of the proximal AA were -0.203 (p=0.01), -0.121 (p=0.129), 0.304 (p=0.0001), and 0.299 (p=0.0001), respectively, in normotensive subjects. In the multivariate analyses, such correlations were observed mainly in the normotensive group, whereas there was no association among hypertensive subjects regardless of antihypertensive medication status.

Conclusion

baPWV is moderately correlated with the stiffness parameters for the proximal AA, mainly in normotensive subjects.

Evaluation of vascular wall elasticity of human digital arteries using alternating current-signal photoplethysmography

Purpose

A simple method of estimating arterial elasticity in the human finger using a volume-oscillometric technique with photoplethysmography was principally studied under the various effects of age, sex, and cold-stress stimulation for testing the capability of using this technique in arterial elasticity analysis.

Methods

Amplitude variations in the alternating current signal of the photoplethysmograph during a continuous change in transmural pressure were analyzed to obtain the blood pressure and the transmural pressure–relative volume difference relationship of the arteries. We first tested the effect of the occluding cuff size on the arterial elasticity analysis in eight subjects (ages 20–45 years) to obtain a suitable cuff size, resulting in the selection of a middle cuff with a 22 mm diameter. Blood pressure and arterial elasticity were measured in six groups of subjects separated into three age-groups of women and men (ages 20–25, 32–45, and over 50 years) for testing the effect of age and sex. Twelve subjects (ages 20–25 years) also had their blood pressure and arterial elasticity measured in three conditions under the influence of the cold-stress stimulation.

Results

Age, sex, and cold-stress stimulation had an impact on mean blood pressure (P < 0.0005, 0.025), whereas pulse pressure and heart rate were statistically unchanged by those factors. Furthermore, an advanced age (over 50 years) was found to induce an increase in relative volume difference values (P < 0.025) and upward shifting of the transmural pressure–relative volume difference relationships, whereas sex, level of mean blood pressure, and cold-stress stimulation had no influence on these forms of the index.

Conclusion

This study showed the usefulness of the relative volume difference as being a mean blood pressure-independent indicator for changes in arterial elasticity.

Insulin Sensitivity and Beta-Cell Function Are Associated with Arterial Stiffness in Individuals without Hypertension

Aim. We investigated the relationship between brachial-ankle pulse wave velocity (baPWV) and glucose levels, insulin sensitivity, and beta-cell function in Chinese individuals with or without hypertension. Methods. We recruited 3137 nondiabetic individuals whose age, body mass index (BMI), glucose levels, blood pressure (BP), lipids, hemoglobin A1C (HbA1c), baPWV, and insulin levels were measured. Results. In normotensive group, 2 h glucose levels (β = 0.046, P < 0.001) associated with baPWV, showed a significant increase in patients with NG as compared to those with DM (P = 0.032). The hypertensive group showed no such differences. The Matsuda index (β = 0.114, P < 0.001) and HOMA- β (β = 0.045, P < 0.001) were negatively correlated with baPWV while lnHOMA-IR (β = 0.196, P = 0.076) and the Quantitative Insulin Sensitivity Check Index (QUICKI) (β = 0.226, P = 0.046) showed a borderline negative correlation. BaPWV significantly decreased (P = 0.032) with an increase in insulin sensitivity in individuals with both normal BP and glucose tolerance. Conclusions. BaPWV was significantly associated with 2 h glucose levels, insulin sensitivity and beta-cell function in normotensive population, whereas in hypertensive individuals, BP was the dominant factor influencing arterial stiffness. Individuals with abnormal insulin sensitivity in the absence of diabetes and hypertension are also at an increased risk of arterial stiffness.

Risk factors related to low ankle-brachial index measured by traditional and modified definition in hypertensive elderly patients

Peripheral arterial disease (PAD) increases with age and ankle-brachial index (ABI) ≤ 0.9 is a noninvasive marker of PAD. The purpose of this study was to identify risk factors related to a low ABI in the elderly using two different methods of ABI calculation (traditional and modified definition using lower instead of higher ankle pressure). A cross-sectional study was carried out with 65 hypertensive patients aged 65 years or older. PAD was present in 18% of individuals by current ABI definition and in 32% by modified method. Diabetes, cardiovascular diseases, metabolic syndrome, higher levels of systolic blood pressure and pulse pressure, elevated risk by Framingham Risk Score (FRS), and a higher number of total and antihypertensive drugs in use were associated with low ABI by both definitions. Smoking and LDL-cholesterol were associated with low ABI only by the modified definition. Low ABI by the modified definition detected 9 new cases of PAD but cardiovascular risk had not been considered high in 3 patients when calculated by FRS. In conclusion, given that a simple modification of ABI calculation would be able to identify more patients at high risk, it should be considered for cardiovascular risk prediction in all elderly hypertensive outpatients.

Correlation of arterial blood pressure and compliance with left ventricular structure and function in the very elderly

There are very few data on the relationship between systolic blood pressure (SBP), diastolic blood pressure (DBP), arterial compliance, and left ventricular structure and function, particularly left ventricular hypertrophy (LVH), in the very elderly (>75 years). SBP and arterial stiffness increase with age, and the question is: which of the two is the main stimulus to LVH? This is a cross-sectional study to compare blood pressure and arterial stiffness measures with regard to their correlations with echocardiographic parameters of LV structure and function, controlling for age and cardiovascular risk factors, in a very elderly population. Arterial stiffness was determined by radial pulse waveform using pulse contour analysis. LV dimensions were measured by transthoracic M-mode echocardiography, and diastolic function by tissue Doppler measurements of diastolic mitral annular velocities. There were 179 subjects, all male, with a mean age of 81.8 years. Using age-adjusted partial correlations, SBP, DBP, and mean arterial pressure (MAP) were correlated with parameters of LV structure and function. Correlation coefficients were: SBP versus left ventricular mass index (LVMI), r = 0.246; SBP versus early diastolic mitral annular velocity (MAV), r = -0.179; DBP versus LVMI, r = 0.199; DBP versus MAV, r = -0.199; MAP versus LVMI, r = 0.276; and MAP versus MAV, r = -0.206, all with P < .05. However, neither capacitative nor reflective arterial compliance was significantly correlated with any parameter of LV structure and function. After controlling for age and 10 cardiovascular and metabolic risk factors, the correlation between blood pressure and the measured LV parameters was substantially unchanged, as was the lack of correlation between indices of arterial compliance and the LV indices. Arterial blood pressure is correlated with LV structure and function in the very elderly, but arterial stiffness, as measured by diastolic pulse contour analysis, is not.

Serum high molecular weight adiponectin correlates with arterial stiffness in community-dwelling persons

INTRODUCTION. Serum high molecular weight (HMW) adiponectin, an adipocytokine, which is a protein secreted specifically by adipose tissue, improves insulin sensitivity and plays an important role in the development of metabolic syndrome and cardiovascular disease (CVD). Pulse wave velocity (PWV) is a noninvasive method of measuring arterial stiffness for the assessment of CVD in high-risk populations. We investigated whether serum HMW adiponectin is independently associated with arterial stiffness when evaluated using PWV. METHODS. We randomly recruited 99 men aged 69 ± 9 (mean ± standard deviation) years and 170 women aged 68 ± 7 years during their annual health examination in a single community. Peripheral arterial stiffness was evaluated by mean PWV determined at three points: from the heart to the carotid artery, to the brachial artery, and to the ankle. RESULTS AND CONCLUSIONS. Age-adjusted PWV in all sites other than the heart to the carotid artery decreased progressively with increased serum HMW adiponectin. Age-adjusted mean PWV significantly decreased from the lowest to the highest serum HMW adiponectin group. Multiple linear regression analyses for mean PWV revealed that decreased serum HMW adiponectin levels were significantly associated with increased mean PWV as well as age, BMI, SBP, DBP, prevalence of antihypertensive medication, and eGFR. Inclusion of serum HMW adiponectin into the model further increased the coefficient of determination (R(2)). Multivariate-adjusted mean PWV was significantly lowest in the highest serum HMW adiponectin group.

Vascular compliance is reduced in geriatric people with angiographic coronary atherosclerosis

This study investigated the value of arterial elasticity measurement in the early diagnosis of angiographic coronary artery atherosclerosis in 105 consecutive elderly patients. They were divided into two groups according to the results of selective coronary angiography: 55 with coronary atherosclerosis and 50 with a normal coronary angiogram. The Gensini score of the coronary artery was acquired and capacitive arterial compliance (C1) and oscillatory arterial compliance (C2) were measured. An independent-sample t-test was used to evaluate the difference in C1 and C2 between the two groups. Bivariate analyses were performed to study the association between the Gensini score and C1 and C2. A significant difference between the two groups in C2 was found and the Gensini score of the coronary artery was significantly correlated with C2. Identification of early coronary atherosclerosis in geriatrics may be aided by the prognostic value of C2.

Association of arterial stiffness with HbA1c in 1,000 type 2 diabetic patients with or without hypertension

The objective is to evaluate the association of arterial stiffness [brachial-ankle pulse wave velocity (ba-PWV)] with glycemic control and duration of type 2 diabetes in diabetic subjects with or without hypertension. One thousand Chinese diabetic patients (562 with hypertension, 438 without hypertension) were included in this study. All patients underwent ba-PWV and biochemical measurements. Ba-PWV was significantly higher in diabetic subjects with hypertension than those without hypertension (1779 +/- 341 vs. 1691 +/- 342 cm/s, P < 0.0001), and these subjects were under similar glycemic control (6.9 +/- 1.5 vs. 6.9 +/- 1.3, P = 0.86). In diabetic and hypertensive subjects, ba-PWV was positively associated with HbA1c (1715 +/- 314 vs. 1851 +/- 335 cm/s, in subjects with HbA1c < 6.5% and with HbA1c > 7.0%, respectively, P < 0.0001), as well as duration of diabetes (1671 +/- 342 vs. 1791 +/- 313 vs. 1861 +/- 338 cm/s, in subjects with duration of diabetes <5 years, 5-10 years, and >10 years, respectively, P all < 0.05). In diabetic subjects without hypertension, ba-PWV was not associated with HbA1c (P = 0.47), but associated with duration of diabetes (1503 +/- 272 vs. 1692 +/- 354 cm/s, in subjects with duration of diabetes <5 years and >10 years, respectively, P = 0.0013). Ba-PWV was higher in diabetic subjects with hypertension than in diabetic subjects without hypertension, suggesting the independent effect of hypertension on arterial stiffness in diabetic subjects. Ba-PWV positively correlated with HbA1c and duration of diabetes in subjects with diabetes and hypertension, suggesting the importance of early glycemic control in the prevention of arterial stiffness and vascular complications.

Associations of brachial-ankle pulse wave velocity and carotid atherosclerotic lesions with silent cerebral lesions

Silent cerebral lesions are increasingly found in mass screenings using MRI and magnetic resonance angiography (MRA). The purpose of this paper is to assess the usefulness of two non-invasive clinical tests-carotid ultrasound examination and brachial-ankle pulse wave velocity (baPWV) measurement-for predicting silent cerebral infarction (SCI) and silent intracranial arterial stenosis. Data were collected on 480 asymptomatic adult subjects who participated in a brain screening program at a single hospital between April 2003 and March 2006. All participants underwent baPWV measurement, B-mode ultrasonography of carotid arteries, MRI, and MRA. Data on 476 (99.1%) subjects were included in the analysis. Among these, 273 (57.4%) were male and the mean age was 51.5 years; 161 (33.8%) had carotid plaque; 33 (6.9%) had increased intima-media thickness (IMT); 99 (20.8%) had SCI; and 7 (1.5%) had intracranial arterial stenosis. The multivariate analysis showed that age (odds ratio [OR]: 1.12; 95% confidence interval [CI]: 1.08-1.17), carotid plaque (OR: 2.69; 1.59-4.56), increased IMT (OR: 2.40; 1.02-5.65), and a history of hypertension treatment (OR 2.22; 1.11-4.43) were significantly associated with SCI. Also, increased IMT (OR 9.70: 1.48-63.71) was related to intracranial arterial stenosis. Brachial-ankle PWV was related to SCI (p<0.01) and intracranial stenosis (p=0.01) in univariate analysis but not in multivariate analysis. The presence of carotid plaque and that of increased IMT on ultrasound examination are useful for assessing the risk of SIC. Increased IMT is also predictive of intracranial arterial stenosis.

Influence of different measurement time points on brachial-ankle pulse wave velocity and ankle-brachial index in hemodialysis patients

In order to ensure that they are reliable markers of atherosclerosis and suitable for repetitive follow-up of disease progression and management responses in hemodialysis (HD) patients, brachial-ankle pulse wave velocity (baPWV) and ankle-brachial index (ABI) should be tested to see whether they change with different measurement time points. The aim of this study was to assess whether baPWV and ABI vary according to whether they are measured before HD, after HD, or on the next dialysis-free day. Eighty-nine patients undergoing regular HD were enrolled. The baPWV and ABI were measured 10-30 min before and after HD, and if patients agreed, on the next dialysis-free day. The third measurement of baPWV and ABI, performed 22+/-2 h after HD, was taken in 72 patients (81%). The body weight reduction after HD was 2.5+/-0.9 kg (p<0.001). The brachial and ankle systolic and diastolic blood pressures before HD were significantly higher than those after HD and on the next dialysis-free day (p<or=0.038). Right and left baPWV increased significantly after HD (p<or=0.006), but returned to the pre-dialysis level on the next dialysis-free day. However, the right and left ABI remained constant before and after HD, or on the next dialysis-free day (p>or=0.498). In conclusion, despite the significant decrease in body weight and blood pressures, baPWV increased significantly after HD. In addition, baPWV, but not ABI, may vary at different measurement time points. Therefore, baPWV, but not ABI, should be assessed in a timely manner in HD patients.

Pulse wave velocity as a marker of arteriosclerosis and its comorbidities in Chinese patients

To obtain reliable data on the epidemiology of arteriosclerosis and the comorbidities in patients with hypertension (HP), coronary heart disease (CHD), type 2 diabetes mellitus (T2DM) and stroke, we evaluated the clinical significance of pulse wave velocity (PWV) as an indicator of arteriosclerosis and its comorbidities in Chinese patients. A total of 910 subjects, including 748 Chinese patients with one or more cardiovascular risk factors (80.2% male, mean age 73.69+/-5.03 years) and 162 healthy volunteers (78.4% male, mean age 73.60+/-5.32 years) were recruited into the study. PWV was measured in 910 subjects, and large artery arteriosclerosis was defined as PWV >or=12 m/s. Multivariable logistic regression analyses were performed to identify risk factors associated with arteriosclerosis. The prevalence of large artery arteriosclerosis in the patients overall was 67.4%, and the prevalence was higher in patients with than in those without HP (63.3% vs. 34.0%; odds ratio [OR]: 3.451), T2DM (24.8% vs. 11.1%; OR: 2.854), CHD (56.1% vs. 45.1%; OR: 1.246) and stroke (26.6% vs. 19.2%; OR: 1.236), but the OR values of CHD and stroke did not differ significantly (p>0.05). After multiple logistic regression analysis, female sex, older age, HP and T2DM were risk factors for large artery arteriosclerosis. In conclusion, PWV can be used as a routine measurement to scan arteriosclerosis in patients with HP or T2DM.

Normality of upper and lower peripheral pulse transit time of normotensive and hypertensive children

OBJECTIVES

The ankle-brachial index (ABI) is known to be indicative of sub-clinical peripheral arterial diseases that are correlated with cardiovascular disease risk factors like atherosclerosis or ischemic extremity. Due to its occluding measurement nature, this may not be appealing to less cooperative patients when multiple prolonged screening is required. A simple and non-intrusive approach termed pulse transit time ratio (PTTR) has recently shown to be potential surrogate marker for the prolonged ABI measurement. Other studies have also suggested that subjects with hypertension have stiffer arterial wall and thereby can confound transit time related parameters. Thus, it becomes important to understand the PTTR normality and difference of hypertensive children when compared to those measured from normotensive children.

METHODS

About 55 normotensive (39 male; aged 8.4 +/- 2.3 yr) and 4 hypertensive (4 male; aged 5-10 yr) Caucasian children were recruited from the same geographical location. A customized device was used to compute pulse transit time related measurements. Since the PTTR approach produced a delta value that was similar to that of ABI, possible inter-subject physiologic differences had limited confounding effects on the derived PTTR parameter.

RESULTS

The obtained transit time measurements from the hypertensive children had lower pulse transit time value when compared to their normotensive counterparts. However, the statistical analysis indicated that they had insignificant PTTR difference (p > 0.01) from those seen in the normotensive children.

CONCLUSIONS

The findings herein suggest that stiffer arterial wall may have confounding effects on the derived transit time related measurements but it is limited on the PTTR parameter. Similar to the ABI approach, PTTR may be only confounded by abnormal local changes in either of the measured peripheral arterial wall. Hence, the PTTR technique shows promise to be an ABI marker from this perspective.

Changes in brachial-ankle pulse wave velocity in subclinical hypothyroidism during normalization of thyroid function

OBJECTIVE

Subclinical hypothyroidism affects 5-15% of the population and is associated with increased cardiovascular morbidity, although this is controversial. We recently reported a significant increase in brachial-ankle pulse wave velocity (baPWV), a parameter of arterial stiffening and an independent predictor for cardiovascular events, in subclinical hypothyroidism. The current study was performed to assess changes in enhanced baPWV in subclinical hypothyroidism during normalization of thyroid function.

METHODS

Forty-two subclinical hypothyroid patients (male/female ratio 8/34) were monitored for changes in baPWV before and after levothyroxine (L-T(4)) replacement therapy.

RESULTS

After attaining euthyroidism, 59.5% and 40.5% of the patients showed reduction and increase of baPWV, respectively. Baseline baPWV and pulse pressure were significantly higher in patients with reduced baPWV (1940.3+/-126.4 vs. 1726.4+/-110.4 cm/s, P=0.046; 62.1+/-3.1 vs. 50.7+/-3.7 mmHg, P=0.026, respectively). Baseline baPWV was significantly correlated with baseline pulse pressure in both groups, but the change in baPWV was significantly correlated with baseline pulse pressure only in patients with reduced baPWV (rho=-0.522, P=0.046). The male/female ratio was significantly lower in patients with reduced baPWV (4/21 vs. 7/10), and systolic, diastolic and pulse pressures and pulse rate decreased significantly only in patients with reduced baPWV.

CONCLUSIONS

Our results suggest that L-T(4) replacement therapy may be especially beneficial in female subclinical hypothyroid patients with high baseline baPWV and pulse pressure. The beneficial effects of L-T(4) replacement therapy in decreasing arterial stiffening and thus preventing cardiovascular disease might be limited to this sub-population.

Comparison of Three Measures of the Ankle-Brachial Blood Pressure Index in a General Population

The ankle-brachial blood pressure index (ABI) predicts cardiovasular disease. To our knowledge, no study has compared manual ABI measurements with an automated electronic oscillometric method in a population sample. We enrolled 946 residents (50.8% women; mean age, 43.5 years) from 8 villages in JingNing County, Zhejiang Province, P.R. China. We computed ABI as the ratio of ankle-to-arm systolic blood pressures from consecutive auscultatory or Doppler measurements at the posterior tibial and brachial arteries. We also used an automated oscillometric technique with simultaneous ankle and arm measurements (Colin VP-1000). Mean ABI values were significantly higher on Doppler than auscultatory measurements (1.15 vs. 1.07; p<0.0001) with intermediate levels on oscillometric determination (1.12; p<0.0001 vs. Doppler). The differences among the three measurements were not homogeneously distributed across the range of ABI values. Doppler and oscillometric ABIs were similar below 1.0, whereas above 1.2 Doppler and auscultatory ABIs were comparable. In Bland and Altman plots, the correlation coefficient between differences in Doppler minus oscillometric ABI and ABI level was 0.21 (p<0.0001). The corresponding correlation coefficient for Doppler minus auscultatory ABI was -0.13 (p<0.0001). In conclusion, automated ABI measurements are feasible in large-scale population studies. However, the small differences in ABI values between manual and oscillometric measurements depend on ABI level and must be considered in the interpretation of study results.