Noninvasive Arterial Measurements of Vascular Damage in Healthy Young Adults: Relation to Coronary Heart Disease Risk

IGFBP-1 and IGFBP-2 are associated with a decreased pulse-wave velocity in young, healthy adults

Background and aims

In healthy, young adults we analyzed a panel of cardiovascular disease related proteins in plasma and compared them with the vascular health of the subjects. The aim was to identify proteins with a relationship to the early atherosclerotic process in healthy individuals.

Methods

We employed the proximity extension assay from OLINK proteomics to analyze 92 cardiovascular disease (CVD) related proteins on 833 subjects (men and women, ages 18–26). The women were further divided into an estrogen-using group and non-users. Protein expression was analyzed using principal component analysis (PCA). The following vascular examinations were performed: Pulse-wave velocity (PWV), augmentation index (AIX), carotid-intima media thickness (cIMT).

Results

Three principal components were obtained using PCA to analyze the protein expression. None of the obtained principal components correlated significantly with AIX or cIMT. One of the components, explaining 6% of the total variance of the data, was significantly correlated with PWV. Upon examination of the proteins with the highest factor loadings on this component independently in a multivariable model, adjusting for established CVD risk biomarkers, insulin-like growth factor-binding protein 1 (IGFBP-1) and insulin-like growth factor-binding protein 2 (IGFBP-2) were found to independently, negatively correlate with PWV. Among the established risk factors included in the multivariable model, age was significantly and adversely correlated with all vascular measurements.

Conclusions

In this population of healthy, young adults, groups of CVD related proteins correlate with PWV, but not AIX or cIMT. This group of proteins, of which IGFBP-1 and IGFBP-2 were independently, negatively correlated in a multivariable model with PWV, could have benificial effects on vascular stiffness. The robust association between age and PWV, AIX and cIMT provide insight into the impact of aging on the vasculature, which is detectable even in a population of young, healthy, non-smoking individuals of ages spanning only 8 years.

Supplementary information

The online version contains supplementary material available at 10.1186/s12872-021-01914-w.

Essen Stroke Risk Score Predicts Carotid Atherosclerosis in Chinese Community Populations

BACKGROUND

Carotid atherosclerosis (CA) is closely related to stroke, and Framingham Risk Score (FRS) has been used for CA risk evaluation. However, FRS could only be used for subjects of up to 74 years old. The present study was to determine if Essen Stroke Risk Score (ESRS) could be used to estimate CA risk in community populations without age limits.

METHODS

In the present prospective multi-community screening study, we evaluated the prevalence of CA using high-resolution ultrasound in 521 males and 1039 females (35 to 91 years old). Both FRS and ESRS were calculated for the subjects. Multivariate logistic regression analysis was used to determine the predictive values of FRS and ESRS for CA in these subjects.

RESULTS

Ultrasound data showed that CA was present in 56.2% of the participants (total of 1560). Multivariate logistic regression analysis showed that ESRS was associated with CA with odds ratio (OR): 1.34 (95% confidence interval (CI), 1.12-1.60, p=0.001). Central obesity (OR: 1.40, CI: 1.07-1.83, p=0.015), female (OR: 0.55, CI: 0.39-0.77, p <0.001) and age (OR: 2.63, CI: 2.27-3.06, p <0.001) were also associated with CA. Based on the estimated area under curve (AUC), FRS (AUC 0.775) was better than ESRS (AUC 0.693) (z statistic 6.774, p <0.001) for CA prediction for individuals of ≤74 years old. However, receiver operating characteristic analysis showed ESRS was a good CA predictor for all subjects (AUC of 0.715).

CONCLUSION

ESRS could be used as an alternative to FRS to predict CA in community population of all age.

On the importance of the nonuniform aortic stiffening in the hemodynamics of physiological aging

Mathematical models of the arterial tree constitute a valuable tool to investigate the hemodynamics of aging and pathology. Rendering such models as patient specific could allow for the assessment of central hemodynamic variables of clinical interest. However, this task is challenging, particularly with respect to the tuning of the local area compliance that varies significantly along the arterial tree. Accordingly, in this study, we demonstrate the importance of taking into account the differential effects of aging on the stiffness of central and peripheral arteries when simulating a person’s hemodynamic profile. More specifically, we propose a simple method for effectively adapting the properties of a generic one-dimensional model of the arterial tree based on the subject’s age and noninvasive measurements of aortic flow and brachial pressure. A key element for the success of the method is the implementation of different mechanisms of arterial stiffening for young and old individuals. The designed methodology was tested and validated against in vivo data from a population of n = 20 adults. Carotid-to-femoral pulse wave velocity was accurately predicted by the model (mean error = 0.14 m/s, SD = 0.77 m/s), with the greatest deviations being observed for older subjects. In regard to aortic pressure, model-derived systolic blood pressure and augmentation index were both in good agreement (mean difference of 2.3 mmHg and 4.25%, respectively) with the predictions of a widely used commercial device (Mobil-O-Graph). These preliminary results encourage us to further validate the method in larger samples and consider its potential as a noninvasive tool for hemodynamic monitoring.

NEW & NOTEWORTHY We propose a technique for adapting the parameters of a validated one-dimensional model of the arterial tree using noninvasive measurements of aortic flow and brachial pressure. Emphasis is given on the adjustment of the arterial tree distensibility, which incorporates the nonuniform effects of aging on central and peripheral vessel elasticity. Our method could find application in the derivation of important hemodynamic indices, paving the way for novel diagnostic tools.

Transcutaneous Carbon Dioxide Treatment Is Capable of Reducing Peripheral Vascular Resistance in Hypertensive Patients

AIM

We aimed to investigate the effects of a single carbon dioxide (CO₂) treatment on arterial stiffness by monitoring the changes of aortic pulse-wave velocity (PWV) and aortic augmentation index (AIXao), which are indicators of arterial stiffness.

PATIENTS AND METHODS

PWV and AIXao were measured by an invasively validated oscillometric device. The measurements of stiffness parameters were performed before the CO₂ treatment, and at 1, 4 and 8 h after the first treatment.

RESULTS

Thirty-one patients were included. No significant changes were found in PWV. AIXao decreased significantly 1 h and 4 h after CO₂ treatment compared to baseline values (p=0.034 and p<0.001). AIXao increased 8 h after the CO₂ treatment, but remained significantly lower than baseline AIXao values (p=0.016).

CONCLUSION

CO₂ treatment is capable of reducing peripheral vascular resistance. We hypothesize that CO₂ is not only a temporal vasodilator but is also capable of activating vasodilation pathways.

Allergies are associated with arterial changes in young children

BACKGROUND

Inflammation is important in atherosclerosis development. Whether common causes of inflammation, such as allergies and infections, already exert this influence in early childhood is unknown. The objective of this study was to investigate the association between both allergies and infections with children's vasculature.

DESIGN

This was a longitudinal study in a general population cohort.

METHODS

In 390 five-year-olds of the WHISTLER (Wheezing-Illnesses-Study-LEidsche-Rijn) birth cohort, carotid intima-media thickness (CIMT) and arterial stiffness were obtained ultrasonographically. Physician-diagnosed allergies and infections and recent prescriptions of systemic antihistamines and antibiotics were obtained, as well as parental history of allergies. General linear regression was performed with vascular characteristics as dependent variables and measures of inflammation as independent variables.

RESULTS

Having both a positive parental history of allergy and an allergy diagnosis showed 15.0 µm (95% confidence interval (CI): 2.3-27.8, p = 0.02) larger CIMT than not having such history and diagnosis. Having a positive parental history of allergy only showed 11.9 µm (0.87-23.0, p = 0.04) larger CIMT. Recent use of antihistamines and antibiotics showed 18.8 µm (1.6-35.9, p = 0.03) and 16.1 µm (4.5-27.7, p = 0.01) larger CIMT, respectively. Childhood infections were not clearly related to vascular parameters. Neither allergy nor infections were associated with arterial stiffness.

CONCLUSION

An allergic predisposition is already associated with thicker arterial walls in early childhood.

Relationships between high-sensitive C-reactive protein and markers of arterial stiffness in hypertensive patients. Differences by sex

Background

The present study was designed to evaluate the relationship between high-sensitivity C-reactive protein (hs-CRP) and arterial stiffness according to sex in patients with arterial hypertension.

Methods

A case-series study was carried out in 258 hypertensive patients without antecedents of cardiovascular disease or diabetes mellitus. Nephelometry was used to determine hs-CRP. Office or clinical and home blood pressures were measured with a validated OMRON model M10 sphygmomanometer. Ambulatory blood pressure monitoring was performed with the SpaceLabs 90207 system. Pulse wave velocity (PWV) and central and peripheral augmentation index (AIx) were measured with the SphygmoCor system, and a Sonosite Micromax ultrasound unit was used for automatic measurements of carotid intima-media thickness (IMT). Ambulatory arterial stiffness index and home arterial stiffness index were calculated as “1-slope” from the within-person regression analysis of diastolic-on-systolic ambulatory blood pressure.

Results

Central and peripheral AIx were greater in women than in men: 35.31 ± 9.95 vs 26.59 ± 11.45 and 102.06 ± 20.47 vs 85.97 ± 19.13, respectively. IMT was greater in men (0.73 ± 0.13 vs 0.69 ± 0.10). hs-CRP was positively correlated to IMT (r = 0.261), maximum (r = 0.290) and to peripheral AIx (r = 0.166) in men, and to PWV in both men (r = 0.280) and women (r = 0.250). In women, hs-CRP was negatively correlated to central AIx (r = −0.222). For each unit increase in hs-CRP, carotid IMT would increase 0.05 mm in men, and PWV would increase 0.07 m/sec in men and 0.08 m/sec in women, while central AIx would decrease 2.5 units in women. In the multiple linear regression analysis, hs-CRP explained 10.2% and 6.7% of PWV variability in women and men, respectively, 8.4% of carotid IMT variability in men, and 4.9% of central AIx variability in women.

Conclusions

After adjusting for age, other cardiovascular risk factors and the use of antihypertensive and lipid-lowering drugs, hs-CRP was seen to be positively correlated to carotid IMT in men, and negatively correlated to central AIx in women. The association of hs-CRP to arterial stiffness parameters differs between men and women.

Long-term exposure to air pollution and vascular damage in young adults

BACKGROUND

Long-term exposure to ambient air pollution has recently been linked to atherosclerosis and cardiovascular events. There are, however, very limited data in healthy young people. We examined the association between air pollutants and indicators of vascular damage in a cohort of young adults.

METHODS

We used data from the Atherosclerosis Risk in Young Adults study. We estimated exposure to nitrogen dioxide (NO2), particulate matter less than 2.5 microm in aerodynamic diameter (PM2.5), black smoke, sulfur dioxide (SO2), and various traffic indicators for participants' 2000 home addresses. Exposure for the year 2000 was estimated by land-use regression models incorporating regional background annual air pollution levels, land-use variables, population densities, and traffic intensities on nearby roads. Outcomes were common carotid artery intima-media thickness (n = 745), aortic pulse wave velocity (n = 524), and augmentation index (n = 729).

RESULTS

Exposure contrasts were substantial for NO2, SO2, and black smoke (5th-95th percentiles = 19.7 to 44.9, 2.5 to 5.2, and 8.6 to 19.4 microg/m3, respectively) and smaller for PM2.5 (16.5 to 19.9 microg/m3). The variability of carotid artery intima-media thickness was less than for pulse wave velocity and especially augmentation index (5-95th percentiles = 0.42 to 0.58 mm, 4.9 to 7.4 m/s and -12.3% to 27.3%, respectively). No associations were found between any of the pollutants or traffic indicators and carotid artery intima-media thickness, although PM2.5 effect estimates were in line with previous studies. We observed a 4.1% (95% confidence interval = 0.1% to 8.0%) increase in pulse wave velocity and a 37.6% (2.2% to 72.9%) increase in augmentation index associated with a 25 microg/m3 increase in NO2, and a 5.3% (0.1% to 10.4%) increase in pulse wave velocity with a 5 microg/m3 increase in SO2. PM2.5 and black smoke were not associated with either of these 2 outcomes.

CONCLUSIONS

Air pollution may accelerate arterial-wall stiffening in young adults. Small outcome variability and lack of residential mobility data may have limited the power to detect an effect on intima-media thickness.

Noninvasive measurement of central vascular pressures with arterial tonometry: clinical revival of the pulse pressure waveform?

The arterial pulse has historically been an essential source of information in the clinical assessment of health. With current sphygmomanometric and oscillometric devices, only the peak and trough of the peripheral arterial pulse waveform are clinically used. Several limitations exist with peripheral blood pressure. First, central aortic pressure is a better predictor of cardiovascular outcome than peripheral pressure. Second, peripherally obtained blood pressure does not accurately reflect central pressure because of pressure amplification. Lastly, antihypertensive medications have differing effects on central pressures despite similar reductions in brachial blood pressure. Applanation tonometry can overcome the limitations of peripheral pressure by determining the shape of the aortic waveform from the radial artery. Waveform analysis not only indicates central systolic and diastolic pressure but also determines the influence of pulse wave reflection on the central pressure waveform. It can serve as a useful adjunct to brachial blood pressure measurements in initiating and monitoring hypertensive treatment, in observing the hemodynamic effects of atherosclerotic risk factors, and in predicting cardiovascular outcomes and events. Radial artery applanation tonometry is a noninvasive, reproducible, and affordable technology that can be used in conjunction with peripherally obtained blood pressure to guide patient management. Keywords for the PubMed search were applanation tonometry, radial artery, central pressure, cardiovascular risk, blood pressure, and arterial pulse. Articles published from January 1, 1995, to July 1, 2009, were included in the review if they measured central pressure using radial artery applanation tonometry.

Aortic augmentation index: reference values in a large unselected population by means of the SphygmoCor device

BACKGROUND

Arterial stiffness and pulse wave reflection are associated with cardiovascular disease (CVD). Pulse wave analyses (PWAs) allow the estimation of the central augmentation index (AIx), a measurement of pulse wave reflection. To understand the predictive role of AIx, reference values for AIx are needed.

METHODS

This population study is based on 4,561 subjects from The Copenhagen City Heart Study, an ongoing epidemiological survey started in 1976, including subjects randomly chosen from the population in Copenhagen, Denmark. We calculated and internally validated reference values of AIx measured by the SphygmoCor device in a cohort without known CVD or diabetes, and with low risk of CVD according to HeartScore using gender-specific multiple regression analyses adjusting for age, heart rate, and height.

RESULTS

AIx was significantly higher in women than in men, 30% vs. 22%, (P < 0.001) and the increase in AIx with age was curvilinear. There were 972 subjects in the low-risk cohort with mean AIx 28% in women (N = 565) and 18% in men (N = 407) (P < 0.001). We report the following internally validated reference equations for AIx: men: AIx = 79.20 + 0.63 (age) - 0.002 (age(2)) - 0.28 (heart rate) - 0.39 (height). Women: AIx = 56.28 + 0.90 (age) - 0.005 (age(2)) - 0.34 (heart rate) - 0.24 (height). AIx appeared to increase with increasing risk of CVD according to HeartScore.

CONCLUSIONS

We report a novel and internally validated gender-specific equation including age, heart rate, and height to calculate reference values for AIx.

Pulse wave velocity is more closely associated with cardiovascular risk than augmentation index in the relatively low-risk population

Pulse wave velocity (PWV) and augmentation index (AI) are both indirect indicators of arterial stiffness, which is an independent predictor of morbidity and mortality in cardiovascular diseases. The aim of this study was to assess the association between carotid AI (CAI), carotid-femoral PWV (CFPWV), and Framingham risk score (FRS), and to evaluate the factors determining CAI and CFPWV. Carotid AI and CFPWV were measured by applanation tonometry in 177 consecutive subjects without evidence of significant cardiovascular disease. Correlations between CAI and FRS and CFPWV and FRS were analyzed and major determinants of CAI and CFPWV were assessed. The mean age was 60.5 +/- 11.9 years and 112 (63%) of study patients were men. There was a significant association between CFPWV and FRS (r = 0.417, P < 0.001) and a weaker but also significant relation between CAI and FRS (r = 0.267, P < 0.001). CFPWV was significantly related to FRS in both men and women (P < 0.001 in both sexes), whereas the relation between CAI and FRS was significant only in women (P < 0.001). Our results suggest that CFPWV may be associated with CVD risk irrespective of sex, whereas CAI may be associated with CVD risk in women only.

Arterial stiffness as a risk factor for coronary atherosclerosis

The major pathophysiologic process of coronary atherosclerosis is a defect or injury of the arterial endothelial function. The rate of progression of coronary atherosclerosis is highly variable and mainly determined by risk contributors such as lipids, glucose, and smoking. Coronary plaque rupture is the precipitating factor for clot formation and acute coronary events. Measurement of arterial stiffness with different noninvasive techniques provides information about the functional and structural vascular changes at the level of the aorta, muscular conduit arteries, the peripheral branches, and the microvascular components. Arterial stiffness has been related to the Framingham and other cardiovascular risk scores. Large artery stiffness contributes to exercise-induced myocardial ischemia in patients with coronary artery disease. It can predict the outcome after coronary interventions. There is now evidence that arterial stiffness is a predictor for cardiovascular events in the general population, in patients with hypertension, end-stage renal disease, impaired glucose intolerance, and coronary artery disease. Future studies are warranted to demonstrate the value of follow-up of arterial stiffness as a marker of reduction of arterial wall damage during antihypertensive, antidiabetic, and lipid-lowering therapy. Promising study results show that measurement of arterial stiffness could become an important part of the routine assessment of patients in daily practice.

Early risk factors, job strain, and atherosclerosis among men in their 30s: the Cardiovascular Risk in Young Finns Study

We examined whether preemployment influences confounded the association between job strain and atherosclerosis. We assessed biological, familial, and socioeconomic risk factors of coronary heart disease at 12 to 18 years of age and job strain and carotid artery intima-media thickness at 33 to 39 years of age for a cohort of 358 men. Adolescent risk factors predicted adult intima-media thickness but had little effect on the dose-response relation between greater job strain and greater intima-media thickness. Pre-employment influences did not confound the association between job strain and atherosclerosis.