Intima-media thickness and diameter of carotid and femoral arteries in children, adolescents and adults from the Stanislas cohort: effect of age, sex, anthropometry and blood pressure

Reference values of carotid intima-media thickness and arterial stiffness in Chinese adults based on ultrasound radio frequency signal: A nationwide, multicenter study

BACKGROUND

Carotid intima-media thickness (IMT) and diameter, stiffness, and wave reflections, are independent and important clinical biomarkers and risk predictors for cardiovascular diseases. The purpose of the present study was to establish nationwide reference values of carotid properties for healthy Chinese adults and to explore potential clinical determinants.

METHODS

A total of 3053 healthy Han Chinese adults (1922 women) aged 18-79 years were enrolled at 28 collaborating tertiary centers throughout China between April 2021 and July 2022. The real-time tracking of common carotid artery walls was achieved by the radio frequency (RF) ultrasound system. The IMT, diameter, compliance coefficient, β stiffness, local pulse wave velocity (PWV), local systolic blood pressure, augmented pressure (AP), and augmentation index (AIx) were then automatically measured and reported. Data were stratified by age groups and sex. The relationships between age and carotid property parameters were analyzed by Jonckheere-Terpstra test and simple linear regressions. The major clinical determinants of carotid properties were identified by Pearson's correlation, multiple linear regression, and analyses of covariance.

RESULTS

All the parameters of carotid properties demonstrated significantly age-related trajectories. Women showed thinner IMT, smaller carotid diameter, larger AP, and AIx than men. The β stiffness and PWV were significantly higher in men than women before forties, but the differences reversed after that. The increase rate of carotid IMT (5.5 μm/year in women and 5.8 μm/year in men) and diameter (0.03 mm/year in both men and women) were similar between men and women. For the stiffness and wave reflections, women showed significantly larger age-related variations than men as demonstrated by steeper regression slopes (all P for age by sex interaction <0.05). The blood pressures, body mass index (BMI), and triglyceride levels were identified as major clinical determinants of carotid properties with adjustment of age and sex.

CONCLUSIONS

The age- and sex-specific reference values of carotid properties measured by RF ultrasound for healthy Chinese adults were established. The blood pressures, BMI, and triglyceride levels should be considered for clinical application of corresponding reference values.

Structural and Mechanical Properties of Human Superficial Femoral and Popliteal Arteries

The femoropopliteal artery (FPA) is the main artery in the lower limb. It supplies blood to the leg muscles and undergoes complex deformations during limb flexion. Atherosclerotic disease of the FPA (peripheral arterial disease, PAD) is a major public health burden, and despite advances in surgical and interventional therapies, the clinical outcomes of PAD repairs continue to be suboptimal, particularly in challenging calcified lesions and biomechanically active locations. A better understanding of human FPA mechanical and structural characteristics in relation to age, risk factors, and the severity of vascular disease can help develop more effective and longer-lasting treatments through computational modeling and device optimization. This review aims to summarize recent research on the main biomechanical and structural properties of human superficial femoral and popliteal arteries that comprise the FPA and describe their anatomy, composition, and mechanical behavior under different conditions.

An in silico study of the effects of cardiovascular aging on carotid flow waveforms and indexes in a virtual population

Cardiovascular aging is strongly associated with increased risk of cardiovascular disease and mortality. Moreover, health and lifestyle factors may accelerate age-induced alterations, such as increased arterial stiffness and wall dilation, beyond chronological age, making the clinical assessment of cardiovascular aging an important prompt for preventative action. Carotid flow waveforms contain information about age-dependent cardiovascular properties, and their ease of measurement via noninvasive Doppler ultrasound (US) makes their analysis a promising tool for the routine assessment of cardiovascular aging. In this work, the impact of different aging processes on carotid waveform morphology and derived indexes is studied in silico, with the aim of establishing the clinical potential of a carotid US-based assessment of cardiovascular aging. One-dimensional (1-D) hemodynamic modeling was employed to generate an age-specific virtual population (VP) of N = 5,160 realistic carotid hemodynamic waveforms. The resulting VP was statistically validated against in vivo aging trends in waveforms and indexes from the literature, and simulated waveforms were studied in relation to age and underlying cardiovascular parameters. In our study, the carotid flow augmentation index (FAI) significantly increased with age (with a median increase of 50% from the youngest to the oldest age group) and was strongly correlated to local arterial stiffening (r = 0.94). The carotid pulsatility index (PI), which showed less pronounced age variation, was inversely correlated with the reflection coefficient at the carotid branching (r = -0.88) and directly correlated with carotid net forward wave energy (r = 0.90), corroborating previous literature where it was linked to increased risk of cerebrovascular damage in the elderly. There was a high correlation between corrected carotid flow time (ccFT) and cardiac output (CO) (r = 0.99), which was not affected by vascular age. This study highlights the potential of carotid waveforms as a valuable tool for the assessment of cardiovascular aging.NEW & NOTEWORTHY An age-specific virtual population was generated based on a 1-D model of the arterial circulation, including newly defined literature-based specific age variations in carotid vessel properties. Simulated carotid flow/velocity waveforms, indexes, and age trends were statistically validated against in vivo data from the literature. A comprehensive study of the impact of aging on carotid flow waveform morphology was performed, and the mechanisms influencing different carotid indexes were elucidated. Notably, flow augmentation index (FAI) was found to be a strong indicator of local carotid stiffness.

Quantitative assessment of carotid ultrasound diameter measurements in the operating room: a comparable analysis of long-axis versus rotated and tilted orientation

Objective. Carotid ultrasound (US) has been studied as a non-invasive alternative for hemodynamic monitoring. A long-axis (LA) view is traditionally employed but is difficult to maintain and operator experience may impact the diameter estimates, making it unsuitable for monitoring. Preliminary results show that a new, i.e. rotated and tilted (RT) view is more robust to motion and less operator-dependent. This study aimed to quantitatively assess common carotid diameter estimates obtained in a clinical setting from an RT view and compare those to corresponding estimates obtained using other views.Approach. Carotid US measurements were performed in 30 adult cardiac-surgery patients (26 males, 4 females) with short-axis (SA), LA, and RT probe orientations, the first being used as a reference for measuring the true vessel diameter. Per 30 s acquisition, the median and spread in diameter values were computed, the latter representing a measure of robustness, and were statistically compared between views.Main results. The median (IQR) over all the patients of the median diameter per 30 s acquisition was 7.15 (1.15) mm for the SA view, 7.03 (1.51) mm for the LA view, and 6.99 (1.72) mm for the RT view. The median spread in diameter values was 0.18 mm for the SA view, 0.16 mm for the LA view, and 0.18 mm for the RT view. There were no statistically significant differences between views in the median diameter values (p= 0.088) or spread (p= 0.122).Significance. The RT view results in comparable and equally robust median carotid diameter values compared to the reference. These findings open the path for future studies investigating the use of the RT view in new applications, such as in wearable ultrasound devices.

Effects of polyphenol supplementation on hepatic steatosis, intima-media thickness and non-invasive vascular elastography in obese adolescents: a pilot study protocol

INTRODUCTION

Non-alcoholic fatty liver disease (NAFLD) is increasingly prevalent in obese adolescents. Increased systemic inflammation and decreased gut microbial diversity linked to obesity affect the liver and are also associated with cardiovascular diseases in adulthood. However, NAFLD and vascular alterations are reversible.

METHODS AND ANALYSIS

This pilot study evaluated the feasibility of a prospective open-label randomised controlled trial evaluating the effects of polyphenols on NAFLD and vascular parameters in obese adolescents. Children aged 12-18 years with hepatic steatosis (n=60) will be recruited. The participants will be randomised with a 1:1 allocation ratio to receive polyphenol supplementation one time per day for 8 weeks along with the clinician-prescribed treatment (group B, n=30) or to continue the prescribed treatment without taking any polyphenols (group A, n=30). The outcome measures will be collected from both the groups at day 1 before starting polyphenol supplementation, at day 60 after 8 weeks of supplementation and at day 120, that is, 60 days after supplementation. The changes in hepatic steatosis and vascular parameters will be measured using liver and vascular imaging. Furthermore, anthropometric measures, blood tests and stool samples for gut microbiome analysis will be collected. After evaluating the study's feasibility, we hypothesise that, as a secondary outcome, compared with group A, the adolescents in group B will have improved NAFLD, vascular parameters, systemic inflammation and gut microbiome.

ETHICS AND DISSEMINATION

This study is approved by Health Canada and the hospital ethics. Participants and their parents/tutors will both provide consent. Trial results will be communicated to the collaborating gastroenterologists who follow the enrolled participants. Abstracts and scientific articles will be submitted to high-impact radiological societies and journals.

CLINICALTRIALS

gov ID: NCT03994029. Health Canada authorisation referral number: 250 811. Protocole version 13, 2 June 2023.

TRIAL REGISTRATION NUMBER

NCT03994029.

Normal pediatric values of carotid artery intima-media thickness measured by B-mode ultrasound and radiofrequency echo tracking respecting the consensus: a systematic review

BACKGROUND

Carotid artery intima-media thickness (IMT) is a sub-clinical radiologic marker of atherosclerosis in children. It is associated with adult-onset vascular disease.

OBJECTIVE

To determine normal pediatric values of IMT from results observed in the literature.

METHODS

Our systematic review was conducted according to PRISMA guidelines. We reviewed 2298 English articles from inception to February 2023. Inclusion criteria included studies evaluating B-mode and radiofrequency (RF)-based IMT measurements based on the American Heart Association, the Association for European Pediatric Cardiology, the Mannheim Consensus, and the American Society of Echocardiography recommendations. A meta-analysis of aggregate data was conducted to obtain the confidence interval (CI) for IMT, using a 95% confidence level.

RESULTS

We obtained 88 B-mode-based IMT measurement studies with 6184 children and six radiofrequency echo-tracking-based studies with 766 children. Mean IMT in the pediatric population was 0.43 mm, 95% [CI] 0,42 to 0.44, using the B-mode technique, and 0.41 mm, 95% [CI] 0.36 to 0.45 using the radiofrequency technique. No significant relationship was detected between IMT and age (p value = 0.83). Finally, no significant effect of sex on IMT was found (p value = 0.82 for B-mode and p value = 0.62 for RF).

CONCLUSION

Based on the studies selected in this literature review, we were unable to conclude that there was a significant difference between the average IMT of boys and girls. No relationship was demonstrated between age and IMT. IMT is technique-specific, and normal values should be interpreted according to recommendations of recognized consensus to counteract the current heterogeneity in literature.

CLINICAL RELEVANCE STATEMENT

Technique and children-specific Intima media thickness measurements help clinicians and scientists to assess the risk of atherosclerosis in children.

KEY POINTS

• Intima-media thickness (IMT) does not correlate with age in children without risk factors. • According to current literature, there is no difference in IMT between healthy boys and girls. • There is heterogeneity, even with studies abiding by the official consensus.

Association of blood pressure and heart rate with carotid markers of vascular remodeling in the young: a case for early prevention

OBJECTIVE

The association of childhood blood pressure (BP) and heart rate (HR) with intermediate markers of cardiovascular disease several decades later has been shown, but studies on more short-term outcomes are scarce. Using population-based data, this study investigates the association of four BP parameters and HR in childhood with three carotid markers for vascular remodeling one decade later.

METHODS

At the 11-year follow-up, 4607 participants of the nationwide KiGGS cohort aged 14 to 28 years had semi-automated sonographic carotid intima media thickness (CIMT) measurements. We investigated associations of baseline (age 3-17 years) and follow-up SBP, DBP, mean arterial pressure (MAP), pulse pressure (PP) and resting heart rate (RHR), with CIMT and lumen diameter at or above the 90th percentile and distensibility coefficient at or below the tenth percentile in logistic regressions. Analyses were further adjusted using a composite cardiovascular risk (CVR) score of BMI, triglycerides, total/HDL-cholesterol-ratio and HbA1c.

RESULTS

SBP, DBP, MAP and RHR were significantly and similarly associated with all carotid measures 11 years later, for example an odds ratio (OR) of 1.17 [confidence interval (CI) 1.06-1.29] for one standard deviation SBP increase with elevated CIMT when adjusting for sex, age and CVR score. Cross-sectionally, the strongest association was found for MAP with reduced distensibility coefficient (OR 1.76; CI 1.59-1.94).

CONCLUSION

This population-based cohort study shows robust and consistent associations between childhood BP and RHR and three carotid measures of vascular remodeling only one decade later, clearly underscoring the potential importance of preventing high BP already early in the life course.

Can Surrogate Markers Help Define Cardiovascular Disease in Youth?

PURPOSE OF REVIEW

Non-invasive measurements such as arterial stiffness serve as proxy surrogates for detection of early atherosclerosis and ASCVD risk stratification. These surrogate measurements are influenced by age, gender, and ethnicity and affected by the physiological changes of puberty and somatic growth in children and adolescents.

RECENT FINDINGS

There is no consensus of the ideal method to measure surrogate markers in youth (< 18 years of age), nor standardized imaging protocols for youth. Currently, pediatric normative data are available but not generalizable. In this review, we provide rationale on how currently used surrogates can help identify subclinical atherosclerosis in youth and affirm their role in identifying youth at risk for premature CVD.

A Systematic Review of the Associations of Adiposity and Cardiorespiratory Fitness With Arterial Structure and Function in Nonclinical Children and Adolescents

PURPOSE

To summarize the evidence on associations of adiposity and cardiorespiratory fitness (CRF) with arterial structure and function in nonclinical children and adolescents.

METHODS

Two researchers conducted a search in 5 electronic databases in April 2022 to find studies in nonclinical youth (age 5-17.9 y) reporting multivariable associations. Studies were eligible if adiposity and/or CRF were used as the predictor and arterial structure and/or function was the outcome. The Quality Assessment Tool for Quantitative Studies was used to assess methodological quality for experimental studies, and a modified version was used for observational studies.

RESULTS

Ninety-nine studies (72.7% cross-sectional) were included. Ninety-four assessed associations between adiposity and arterial outcomes, most using overall body proportion (n = 71), abdominal (n = 52), or whole-body adiposity (n = 40). Most evidence was inconsistent or nonsignificant, but 59 studies suggested higher abdominal adiposity and worse body proportion were associated with adverse arterial outcomes. Twenty-one assessed associations between CRF and arterial outcomes, with findings inconsistent. Most evidence was rated weak in quality.

CONCLUSION

While high adiposity may contribute to poor arterial outcomes, evidence is limited regarding CRF. Future studies should disentangle these associations by studying youth with healthy adiposity but poor CRF, or vice versa, using longitudinal or experimental study designs.

Current applications for measuring pediatric intima-media thickness

Intima-media thickness is a known subclinical radiologic marker of the early manifestations of atherosclerotic disease. It is the thickness of the vessel wall, most often the carotid artery. Intima-media thickness is measured on conventional US manually or automatically. Other measurement techniques include radiofrequency US. Because there is variation in its measurement, especially in children, several recommendations have been set to increase the measurement's validity and comparability among studies. Despite these recommendations, several pitfalls should be avoided, and quality control should be performed to avoid erroneous interpretation. This article summarizes current literature in relation to the clinical applications for intima-media thickness measurement in children with known risk factors such as obesity, liver steatosis, hypercholesterolemia, diabetes, hypertension, systemic inflammatory diseases, cancer survival, kidney and liver transplant, and sickle cell disease or beta thalassemia major. Most potential indications for intima-media thickness measurement remain in the research domain and should be interpreted combined with other markers. The objective of diagnosing an increased intima-media thickness is to start a multidisciplinary treatment approach to prevent disease progression and its sequelae in adulthood.

Quantile regression to examine the association of air pollution with subclinical atherosclerosis in an adolescent population

BACKGROUND

Air pollution has been associated with carotid intima-media thickness test (CIMT), a marker of subclinical atherosclerosis. To our knowledge, this is the first study to report an association between ambient air pollution and CIMT in a younger adolescent population.

OBJECTIVE

To investigate the associations beyond standard mean regression by using quantile regression to explore if associations occur at different percentiles of the CIMT distribution.

METHODS

We measured CIMT cross-sectionally at the age of 16 years in 363 adolescents participating in the Dutch PIAMA birth cohort. We fit separate quantile regressions to examine whether the associations of annual averages of nitrogen dioxide (NO₂), fine particulate matter (PM_2.5), PM_2.5 absorbance (a marker for black carbon), PM_coarse and ultrafine particles up to age 14 assigned at residential addresses with CIMT varied across deciles of CIMT. False discovery rate corrections (FDR, p < 0.05 for statistical significance) were applied for multiple comparisons. We report quantile regression coefficients that correspond to an average change in CIMT (µm) associated with an interquartile range increase in the exposure.

RESULTS

PM_2.5 absorbance exposure at birth was statistically significantly (FDR < 0.05) associated with a 6.23 µm (95% CI: 0.15, 12.3) higher CIMT per IQR increment in PM_2.5 absorbance in the 10th quantile of CIMT but was not significantly related to other deciles within the CIMT distribution. For NO₂ exposure we found similar effect sizes to PM_2.5 absorbance, but with much wider confidence intervals. PM_2.5 exposure was weakly positively associated with CIMT while PM_coarse and ultrafine did not display any consistent patterns.

CONCLUSIONS

Early childhood exposure to ambient air pollution was suggestively associated with the CIMT distribution during adolescence. Since CIMT increases with age, mitigation strategies to reduce traffic-related air pollution early in life could possibly delay atherosclerosis and subsequently CVD development later in life.

Validation of an aging virtual population for the study of carotid hemodynamics

The analysis of carotid ultrasound (US) flow, velocity, and diameter waveforms provides important information about cardiovascular and circulatory health. These can be used to derive clinical indices of atherosclerosis, vascular aging, and hemodynamic status. To derive clinical insight from carotid waveforms, it is essential to understand the relationship of the observed variability in morphology with the underlying hemodynamic status and cardiovascular properties. For this purpose, using a one-dimensional modeling approach, we have developed and validated a virtual population that is able to realistically simulate carotid waveforms of healthy subjects aged between 10 and 80 years old.Clinical Relevance-Our virtual population of carotid waveforms can support the interpretation of US patient data. It can be used, e.g., to investigate how waveform morphology and derived indices relate to individual arterial and cardiac properties.

Impact of body mass index on duplex parameters of cranial vessels among the Egyptian population

Background

Obesity is a major health problem that affects different vascular systems, including cerebrovascular circulation. Carotid duplex is the best screening tool for early diagnosis of cerebrovascular changes in relation to different risk factors including obesity. The present study aims to evaluate the effect of body mass index on the parameters of extracranial vessels in healthy subjects using vascular duplex ultrasonography.

Results

The intimal medial thickness in the common carotid is found to increase as the body mass index and body weight increase (directly related), with this increase being significant (P-value < 0.05).

Conclusion

These findings indicate that increase in body mass index can adversely affect duplex parameters of the common carotid artery.

Clinical trial registration NCT03252652. Registered August 16th 2017

Age-dependent Intracranial Artery Morphology in Healthy Children

PURPOSE

Evaluation of intracranial artery morphology plays an important role in diagnosing a variety of neurovascular diseases. In addition to clinical symptoms, diagnosis currently relies on qualitative rather than quantitative evaluation of vascular imaging sequences, such as magnetic resonance angiography (MRA). However, there is a paucity of literature on normal arterial morphology in the pediatric population across brain development. We aimed to quantitatively assess normal, age-related changes in artery morphology in children.

METHODS

We performed retrospective analysis of pediatric MRA data obtained from a tertiary referral center. An MRA dataset from 98 children (49 boys/49 girls) aged 0.6-20 years (median = 11.5 years) with normal intracranial vasculature was retrospectively collected between 2011 and 2018. All arteries were automatically segmented to determine the vessel radius. Using an atlas-based approach, the average radius and density of arteries were measured in the three main cerebral vascular territories and the radius of five major arteries was determined at corresponding locations.

RESULTS

The radii of the major arteries as well as the average artery radius and density in the different vascular territories in the brain remained constant throughout childhood and adolescence (|r| < 0.369 in all cases).

CONCLUSION

This study presents the first automated evaluation of intracranial vessel morphology on MRA across childhood. Our results can serve as a framework for quantitative evaluation of cerebral vessel morphology in the setting of pediatric neurovascular diseases.

The relation between increased carotid intima-media thickness with fibrin monomers in obese children

AIM

This study aimed to investigate the association between carotid intima-media changes that play a part in the atherosclerotic process in childhood obesity and fibrin monomers as an important indicator of fibrin plaque.

METHODS

This is a cross-sectional study of obese children and non-obese healthy control subjects. Height, weight, body mass index, waist/hip ratio, systolic/diastolic blood pressures were recorded, in addition, biochemistry, haemogram, fibrin monomers and d-dimer were measured in both groups. Right and left common carotid intima-media thicknesses were measured by ultrasonography and mean carotid intima-media thickness was calculated.

RESULTS

Obese children (n = 89, 46.1% girls, median age: 12.6 ± 2.3 years) and healthy control group (n = 40, 52.5% girls, median age: 13.2 ± 2.2 years) were comparable in terms of gender, age and puberty stage. Mean carotid intima-media thickness was higher in obese children than the healthy control group (P = .002). There was no difference between the two groups in terms of fibrin monomers and d-dimer levels. In obese children, there was a weak negative correlation between mean carotid intima-media thickness and fibrin monomers (P = .030, r = -0.233).

CONCLUSION

In obese children, mean carotid intima-media thickness was determined higher, as an early indicator of atherosclerosis. We want to emphasise that obese children are at risk for cardiovascular disease and should be evaluated in terms of atherosclerosis. This study investigates the relation between increased carotid intima-media thickness and fibrin monomers, in children, the first time in Literature.

Fat mass and vascular health in overweight/obese children

BACKGROUND AND AIM

Childhood obesity is one of the most serious public health challenges of the 21st century. Body mass index (BMI), the most widely used marker of body fatness, has serious limitations, particularly in children, since it does not accurately discriminate between lean and fat mass. Aim of our study was to investigate if the estimate of fat mass, as derived by a new prediction model, was associated with carotid intima media thickness (IMT) and the cross-sectional area of the intima media complex (CSA-IMC) in overweight or obese children.

METHODS AND RESULTS

As many as 375 overweight/obese Italian children, 54.7% males, aged 5-15 years, admitted to a tertiary care hospital, were consecutively enrolled in a study on cardiovascular markers of atherosclerosis. All children underwent an ultrasound carotid examination. Mean weight was 62.2 ± 20.8 Kg and fat-mass was 26.2 ± 10.7 Kg. Multiple regression analyses showed a significant association of fat mass with carotid IMT (β 0.156, p 0.01) and CSA-IMC (β 0.216, p < 0.001); these associations remained significant after controlling for the main cardiovascular risk factors (age, sex, blood pressure, HOMA-index, triglycerides, LDL-cholesterol, HDL-cholesterol, birth weight and high-sensitivity C-reactive protein).

CONCLUSION

Fat mass calculated with the new formula is independently associated with subclinical atherosclerosis in overweight/obese children.

Vascular diameter and intima-media thickness to diameter ratio values of the carotid artery in 642 healthy children

In children, arterial alterations occur with increased intima-media thickness as well as vascular diameter enlargement. Both conditions correlate with higher cardiovascular risk in adults, and both the array and proportion of these alterations are important hemodynamic parameters. In terms of functional adaptation processes, they influence several arterial wall properties as for example the shear and tensile stress of the vessel. There are no reference values for the vascular diameter and intima-media thickness/diameter ratio of the carotid artery in children. Therefore, this study aimed to assess vascular diameter, intima-media thickness/diameter ratio and related tensile stress values in children and to further investigate the influence of sex, age, body mass index, and blood pressure. The parameters were measured with high-resolution semi-automated ultrasound. Sex- and age-dependent values were calculated with the LMS method for a cross-sectional sample of 642 healthy, non-obese children aged 8-17 years. The mean vascular diameter was 5.45 ± 0.46 mm; the median intima-media thickness/diameter ratio was 0.085 (0.079-0.092); the median tensile stress was 105.4 (95.2-116.4) kPa. The vascular diameter and the tensile stress were higher, and the intima-media thickness/diameter ratio was lower in boys than in girls. In comparison to the normal weight study population the excludedobese children had a significantly higher diameter, a lower intima-media thickness/diameter ratio, and a higher tensile stress. In multiple regression analyses of diameter, intima-media thickness/diameter ratio, and tensile stress, all parameters were influenced by sex and body mass index. Furthermore, systolic and diastolic blood pressure significantly influenced the vascular diameter, and systolic blood pressure significantly influenced the intima-media thickness/diameter ratio. Conclusion: This study is the first to report values for the diameter, the intima-media thickness/diameter ratio of the carotid artery, and the related tensile stress allowing a more differentiated view of cardiovascular adaptations as it combines structural and functional vascular parameters. What is known: • Intima-media thickness and vascular diameter are related to a higher cardiovascular risk in adults • The intima-media thickness/diameter ratio gives information about hemodynamic and functional vessel adaptation What is new: • Values for vascular diameter, intima-media thickness/diameter ratio, and tensile stress of the carotid artery in children are presented in this study • Intima-media thickness as a surrogate marker for arterial health in children should be complemented by intima-media thickness/diameter ratio measurement.

Carotid IMT and Stiffness in the KiGGS 2 National Survey: Third-Generation Measurement, Quality Algorithms and Determinants of Completeness

Carotid intima-media thickness (cIMT) and carotid stiffness (CS) are important markers of atherosclerotic risk in the young. We assessed a novel third-generation method for its applicability in large population-based epidemiologic studies to determine strengths, limitations, completeness and predictors of unsuccessful measurement. Four thousand seven hundred ninety-eight 14- to 31-y-old participants of the German KiGGS cohort, which is based on a nationally representative sample with 11-y follow-up, underwent B-mode ultrasound examinations of the left and right common carotid artery with semi-automatic edge detection and automatic electrocardiogram-gated real-time quality control based on a sophisticated snake algorithm and subpixel interpolation. Overall completeness was 98% for far wall cIMT and 89% for CS parameters. Plane-specific completeness varied from 92%-96% for far wall and from 64%-69% for near-wall cIMT. Obesity independently predicted unsuccessful cIMT and CS measurements with odds ratios of 12.67 (95% confidence interval: 5.50-29.19) and 7.30 (4.87-10.94) compared with non-overweight after adjustment for blood pressure, cholesterol, smoking, hazardous drinking, age, sex and sonographer. Inter- and intra-rater reliabilities of cIMT and CS parameters in a sample of 15 young adults were good or excellent. Third-generation cIMT and CS measurements in the young with semi-automatic edge-detection and automatic real-time quality control has been successfully standardized with high reliability and very high completeness in a national survey setting. This provides a strong methodological foundation for further validation of the predictive value of cIMT and CS for atherosclerotic risk in the young.

The Effect of Long-Term Atorvastatin Therapy on Carotid Intima-Media Thickness of Children With Dyslipidemia

Carotid intima-media thickness (cIMT) has been proposed as an early marker of subclinical atherosclerosis in high risk children. Children with heterozygous familial hypercholesterolemia have greater cIMT than matched healthy controls or their unaffected siblings. Statin therapy may delay the progression of cIMT, although long-term studies in children are scarce. We evaluated the effect of atorvastatin treatment on cIMT in children with dyslipidemia. We studied 81 children/adolescents, 27 with severe dyslipidemia (low-density lipoprotein cholesterol [LDL-C] ≥190 mg/dL) and 54 sex- and age-matched healthy controls; LDL-C ≤ 130 mg/dL and lipoprotein (a), Lp(a), ≤30 mg/dL. In the children with dyslipidemia, cIMT was measured twice, before and on treatment (18.2 ± 7.7 months). Anthropometric data, a full lipid profile, liver, kidney, and thyroid function were evaluated. Males with dyslipidemia had a greater cIMT than male controls after adjustment for other factors (P = .049). In addition, a nonstatistically significant decrease in cIMT was observed after treatment (P = .261). Treatment with atorvastatin resulted in a significantly improved lipid profile. Females with dyslipidemia had a significantly thinner cIMT than males. Children with normal and high Lp(a) levels had similar cIMT values. In conclusion, treatment with atorvastatin had a beneficial effect on the lipid profile and cIMT progression in children with severe dyslipidemia.

Carotid Intima-Media Thickness in Healthy Children and Adolescents: Normative Data and Systematic Literature Review

Objectives: Early identification of children at risk of atherosclerosis is of paramount importance for implementing primary preventive measures addressing vascular health. Carotid intima-media thickness (cIMT) is a non-invasive biomarker of atherosclerosis. Semiautomatic radiofrequency-based software-guided technique quality intima-media thickness (RF-QIMT) was used to determine cIMT normative values in a healthy cohort of Caucasian children aged 6 to 18 years.

Study design: In a cross-sectional study, data on age, chronic illness, medication use, and pubertal status was acquired by a questioner. Anthropometric and blood pressure measurements were performed by standardized methods and trained medical personnel. cIMT of the right common carotid artery far wall (1 centimeter proximal to bifurcation) was determined using a multifrequency (3–13 MHz) electronic linear array transducer SL1543, a portable ultrasound device (MyLab Gamma Esaote, Genoa, Italy), and RF-QIMT software. A systematic review of the published normal cIMT in children was done using PRISMA methodology, and identified normative values were compared to those obtained in the presented study.

Results: 1137 non-obese normotensive children (males: n = 512; mean age 12.04 ± 3.52 years, females: n = 625, mean age 12.98 ± 3.83 years) were included. Gender-, age-, and height-specific mean cIMT percentile tables, percentile charts, and LMS tables for the RF-QIMT method were provided. They were comparable to the previously published data on mean cIMT gained by other validated ultrasound imaging techniques. cIMT increased with age, height, hip circumference, and BMI and was higher in males.

Conclusions: Gender-, age-, and height-specific normative cIMT values, using the semiautomatic software-guided RF-QIMT technique, in children aged 6 to 18 years were developed and validated in respect to the previously published pediatric normative cIMT data. It is suggested that the investigated method could be used for the estimation of atherosclerotic risk in children, especially in epidemiological studies.

Feasibility of intraoperative aortic root imaging in congenital heart surgery

BACKGROUND

Intraoperative vascular imaging is a useful tool to evaluate coronary ostia in congenital heart patients with suboptimal preoperative imaging findings. Additionally, vascular imaging has potential value for visualization of the ascending aortic intima media thickness (IMT) in certain clinical scenarios. This study sought to evaluate the feasibility of intraoperative vascular imaging of coronary ostia and IMT during congenital heart surgery.

METHODS

We describe the technique for performance of intraoperative vascular imaging by a pediatric cardiologist using a high-resolution linear sequential array transducer.

RESULTS

Intraoperative vascular imaging was obtained on seven patients. Coronary ostia were normal in all except one. This patient had congenital stenosis of the left coronary ostium discovered during intraoperative imaging and confirmed by the surgeon. In another patient with Williams syndrome, the IMT was noted to be prominent.

CONCLUSIONS

It is feasible to perform intraoperative vascular imaging in less than 5 minutes of operator's time and provides superior visualization of the coronary ostia and IMT.

The association between fat mass and subclinical atherosclerosis in healthy schoolchildren

BACKGROUND AND AIMS

Childhood obesity is associated with increased risk of cardiovascular disease (CVD) later in life. The aims of this study were to investigate the change of atherosclerosis risk factors in three fat mass percentiles and to examine the association between fat mass and atherosclerosis risk factors among a group of schoolchildren.

METHODS

A total of 125 schoolchildren (64 boys) aged 10-15 years were distributed into three groups: (i) the lower fat mass (LFM) group, for participants who reported fat mass ≤50th percentile; (ii) the middle fat mass (MFM) group, for participants who reported fat mass >50th percentile and <75th percentile; and (iii) the higher fat mass (HFM) group for participants who reported ≥ 75th percentiles. Measurements of carotid intima-media thickness (cIMT) using high-resolution B-mode ultrasound, lipemic profile, blood pressure, serum proinflammatory cytokines and soluble adhesion molecules were performed.

RESULTS

Significant differences (p ≤ 0.05) were shown between the three groups in total cholesterol (TC), triglycerides (TG), LDL, interlukien-6 (IL-6), and interlukien-1 beta (IL-1β). Using multiple linear regression analysis of fat mass as the dependent variable with the studied subclinical atherosclerosis risk, fat mass was significantly (p ≤ 0.05) associated with the variation expressed in systolic blood pressure (β = 0.490), diastolic blood pressure (β = 0.470), TC (β = 0.399), TG (β = 0.306), HDL (β = -0.281), LDL (β = 0.446), E-selectin (β = 0.314), and cIMT (β = 0.257).

CONCLUSION

Higher fat mass is associated with increased risk of atherosclerosis in schoolchildren. Atherosclerosis risk factors including biomarkers of inflammation, endothelial dysfunction, a state of dyslipidemia, increased cIMT, and high blood pressure were associated with fat mass. Studies evaluating the appropriate fat mass cut-off points in children and adolescents are needed.

PCSK9 Protein and rs562556 Polymorphism Are Associated With Arterial Plaques in Healthy Middle-Aged Population: The STANISLAS Cohort

Background PCSK9 (Proprotein convertase subtilisin/kexin type 9) binds low-density lipoprotein receptor, preventing its recycling. PCSK9 is a risk predictor and a biotarget in atherosclerosis. The PCSK9-rs562556 variant has been reported as a gain-of-function mutation. The aim of this study was to determine whether the PCSK9-low-density lipoprotein receptor-rs562556 axis is associated with carotid artery plaques between 2 visits separated by almost 20 years in a longitudinal population cohort. Methods and Results The STANISLAS (Suivi Temporaire Annuel Non-Invasif de la Santé des Lorrains Assurés Sociaux) cohort is a longitudinal familial cohort from the Lorraine region of France. Participants attending 2 visits (visit 1 and visit 4) separated by 18.5 years (mean) were included (n=997). Carotid artery plaques were determined with standardized vascular echography. The mean age of the adult population at visit 1 was 42±5 years. At visit 4, 203 (20.4%) participants had arterial plaques. Participants who developed arterial plaques were older (42.7±5.4 versus 41.7±4.7 years), more often male (60% versus 49%), smokers (29% versus 18%), with diabetes mellitus (6% versus 3%), and higher cholesterol levels (low-density lipoprotein cholesterol, 1.6±0.4 versus 1.5±0.3 g/L) (all P<0.05). The independent factors associated with arterial plaques were age, smoking, and low-density lipoprotein cholesterol. Higher PCSK9 levels were associated with arterial plaques on top of the clinical model (odds ratio, 2.14; 95% CI,= 1.28-3.58); the missense mutation coding the single-nucleotide polymorphism rs562556 was associated with both higher PCSK9 concentration and incident carotid arterial plaques. Conclusions Higher PCSK9 concentration was associated with the development of arterial plaques almost 20 years in advance in a healthy middle-aged population. Mutations of the single-nucleotide polymorphism rs562556 associated with both PCSK9 levels and arterial plaques reinforce the potential causality of our findings. PCSK9 inhibitors could be useful for primary cardiovascular prevention.

Assessment of intima-media thickness of the carotid artery and intraluminal diameter of the brachial artery as cardiovascular risk markers in Brazilian adolescents with overweight or obesity

Background The intima-media thickness of the carotid artery (cIMT) and endothelial dysfunction are associated with cardiovascular (CV) disease. Objectives To evaluate the correlation between cIMT, brachial intraluminal diameter and flow-mediated vasodilation on the reactive hyperemia phase in adolescents with obesity with predictors of CV risk. Methods Seventy-three pubertal patients with overweight or obesity were evaluated (45 girls) with a mean (standard deviation [SD]) age of 12.9 (2.5) years. Patients underwent anthropometric measurements and had the lipid profile, oral glucose tolerance test (oGTT) and serum intercellular adhesion molecule-1 (sICAM-1) levels analyzed. The ratios of the waist circumference (WC)/height (WHtR) and triglycerides (TG)/high-density lipoprotein cholesterol (HDL-C), homeostatic model assessment of insulin resistance (HOMA-IR), the Matsuda index and insulin area under the curve (AUC) were calculated. All patients were evaluated for cIMT and arterial blood flow velocity of the brachial artery. Results 75.3% of the patients had high cIMT values. We found a positive correlation between WHtR and cIMT (r = 0.233; p = 0.050). There was a positive correlation between sICAM-1 and insulin AUC (r = 0.323; p = 0.012) and WHtR (r = 0.258; p = 0.047). Patients with abnormal arterial dilation had higher sICAM-1 values (p = 0.02) despite having smaller WHtR (p = 0.046). Conclusions These adolescents with obesity had high cIMT values. Insulin resistance was associated with sICAM-1. Endothelial dysfunction was positively correlated with sICAM-1. There is no consensus about what the best laboratorial approach to evaluate insulin resistance in adolescents is, and the cutoff values of each method are arbitrary. So, as we saw earlier, the association between anthropometric data (WHtR) and ultrasound findings could be useful to evaluate the CV risk of these adolescents with obesity, because of its practical, direct and low-cost value.

Modeling arterial pulse waves in healthy aging: a database for in silico evaluation of hemodynamics and pulse wave indexes

The arterial pulse wave (PW) is a rich source of information on cardiovascular (CV) health. It is widely measured by both consumer and clinical devices. However, the physical determinants of the PW are not yet fully understood, and the development of PW analysis algorithms is limited by a lack of PW data sets containing reference CV measurements. Our aim was to create a database of PWs simulated by a computer to span a range of CV conditions, representative of a sample of healthy adults. The typical CV properties of 25-75 yr olds were identified through a literature review. These were used as inputs to a computational model to simulate PWs for subjects of each age decade. Pressure, flow velocity, luminal area, and photoplethysmographic PWs were simulated at common measurement sites, and PW indexes were extracted. The database, containing PWs from 4,374 virtual subjects, was verified by comparing the simulated PWs and derived indexes with corresponding in vivo data. Good agreement was observed, with well-reproduced age-related changes in hemodynamic parameters and PW morphology. The utility of the database was demonstrated through case studies providing novel hemodynamic insights, in silico assessment of PW algorithms, and pilot data to inform the design of clinical PW algorithm assessments. In conclusion, the publicly available PW database is a valuable resource for understanding CV determinants of PWs and for the development and preclinical assessment of PW analysis algorithms. It is particularly useful because the exact CV properties that generated each PW are known.NEW & NOTEWORTHY First, a comprehensive literature review of changes in cardiovascular properties with age was performed. Second, an approach for simulating pulse waves (PWs) at different ages was designed and verified against in vivo data. Third, a PW database was created, and its utility was illustrated through three case studies investigating the determinants of PW indexes. Fourth, the database and tools for creating the database, analyzing PWs, and replicating the case studies are freely available.

The effect of HIV infection, antiretroviral therapy on carotid intima-media thickness: A systematic review and meta-analysis

AIMS

We performed a systematic review and meta-analysis on the effect of HIV infection and antiretroviral therapy (ART) on carotid intima-media thickness (cIMT) to elucidate the role of HIV infection and ART. Also, an analysis on the role of ethnicity and gender on cIMT in HIV-infected populations was performed.

MAIN METHODS

We searched the PubMed, Web of Science, the WHO websites and International AIDS Society for published observational studies were conducted by two independent reviewers for studies comparing HIV-infected antiretroviral-experienced patients and/or inexperienced with healthy controls on cIMT. The primary outcome was the standardized mean difference (SMD) of cIMT.

FINDINGS

Twenty studies (five cohort, 15 cross-sectional, and two both cohort and cross-sectional studies) were identified comprising 7948 subjects (4656 HIV-infected; 3292 controls). In cohort studies, the standardized mean 1-year change in cIMT between HIV-infected patients and uninfected controls was not significantly different (0.16 mm/yr; 95% CI, -0.16, 0.49; p = 0.326). In 17 cross-sectional studies, the SMD in cIMT was significantly higher in HIV-infected than uninfected persons (0.27 mm; 95% CI, 0.04, 0.49; p = 0.027). HIV-infected patients on ART exhibited significantly higher SMD in cIMT compared to those not on ART (0.75 mm; 95% CI, 0.30, 1.19; p = 0.001). No confounding effect of gender and ethnicity could be established using meta-regression p > 0.05.

SIGNIFICANCE

HIV infection itself and ART appear to influence the progression of cIMT and hence may be risk factors for cardiovascular events. No firm conclusions could be drawn on the effect of ethnic/race and gender differences on cIMT in HIV-infected populations.

Feasibility and Normal Ranges of Arterial Intima-Media Thickness and Stiffness in 2-Year-Old Children: A Pilot Study

INTRODUCTION

In adults, noninvasive assessments of vascular function have been established. However, little is known about the applicability and reference values of these techniques among children < 6 years old and none ≤ 2. We aimed to determine the feasibility of conducting noninvasive vascular assessments in 2-year-old children and the normal range of results in this age group.

METHODS

Carotid intima-media thickness (cIMT) and abdominal aorta IMT (aaIMT), pulse wave velocity (PWV), arterial diameter change, stiffness index (β), and distensibility were assessed in 2-year-old children. IMT was assessed using an automatic contour detection.

RESULTS

The proportion of successful measurements was 72% (42/58) with cIMT 64%, aaIMT 67%, and PWV 43%. Average far wall cIMT was 0.51 mm and 0.40 for aaIMT. Mean PWV was 4.15 m/s, with relatively wider range in stiffness index and distensibility. Common carotid arteries had a higher mean distensibility of 4.58%/10 mmHg compared with 2.98%/10 mmHg for the abdominal aorta. The number of data points automatically detected at far wall cIMT was higher than that in aaIMT (left cIMT: 244 ± 13 and right: 240 ± 23 vs. abdominal 185 ± 63, p < 0.001). Better and more consistent quality was achieved for cIMT than aaIMT measurements. PWV measurement was only feasible in cooperative children with efficient distractions.

CONCLUSIONS

Noninvasive methods for early detection of cardiovascular risks were feasible in at least two-thirds of 2-year-old children. Given the greater feasibility and image quality, cIMT is a preferable option for assessing vascular health in young children.

Predictors and Consequences of Pediatric Hypertension: Have Advanced Echocardiography and Vascular Testing Arrived?

PURPOSE OF REVIEW

Pediatric hypertension is relatively common and associated with future adult hypertension. Elevated blood pressure in youth predicts future adult cardiovascular disease and blood pressure control can prevent progression of pediatric kidney disease. However, pediatric blood pressure is highly variable within a given child and among children in a population.

RECENT FINDINGS

Therefore, modalities to index aggregate and cumulative blood pressure status are of potential benefit in identifying youth in danger of progression from a risk factor of subclinical phenotypic alteration to clinically apparent event. In this review, we advocate for the health risk stratification roles of echocardiographically assessed cardiac remodeling, arterial stiffness assessment, and assessment by ultrasound of arterial thickening in children and adolescents with hypertension.

Modifiable Clinical Correlates of Vascular Health in Children and Adolescents with Dyslipidemia

Atherosclerosis promoting cardiovascular disease risk factors (CVDrf) are highly prevalent among youth in the U.S. Determining which standard modifiable clinical measures (SMCMs) has the greatest impact on vascular structure and function is valuable for the health care provider to help identify children at highest risk. The aim of this study was to determine modifiable outpatient clinical predictors of vascular health in youth with CVDrf. Children and adolescents with CVDrf (n = 120, 13.1 ± 1.9 years, 49% female) were recruited from a pediatric preventive cardiology clinic. The SMCMs included BMI z-score, waist-to-height ratio (WTHR), lipid panel, hemoglobin A1c, blood pressure (BP), presence of tobacco smoke exposure, and presence of hypertriglyceridemic waist (HTW) phenotype (triglycerides ≥ 110 mg/dL and waist circumference ≥ 90 percentile). Vascular function and structure were measured with pulse wave velocity (PWV), central systolic BP (CSP), augmentation index (AIx), and carotid artery intima-media thickness (cIMT). Sex and height specific z-scores for PWV, CSP, and cIMT were used. Multiple linear regression with backwards selection identified SMCMs which strongly predicted vascular function and structure. Among SMCMs, WTHR and HTW were the most frequent predictors of vascular function (PWV: R² = 0.32; CSP: R² = 0.35; AIx R² = 0.13). Other predictors of vascular function included hemoglobin A1C, BP, and BMI z-score. Systolic BP and LDL cholesterol were predictors of vascular structure (cIMT: R² = 0.14). The strongest predictors of vascular health in youth with CVDrf were related to measures of central obesity. Targeting these SMCM in lieu of vascular testing in outpatient clinic setting may be practical to identify children and adolescents at greatest risk for CVD.

Assessing the consequences of gestational diabetes mellitus on offspring's cardiovascular health: MySweetHeart Cohort study protocol, Switzerland

INTRODUCTION

Gestational diabetes mellitus (GDM) is a state of glucose intolerance with onset during pregnancy. GDM carries prenatal and perinatal risks as well as long-term risks for the mother and her child. GDM may be involved in the foetal programming of long-term cardiovascular health. However, evidence is sparse and the effect of GDM on cardiovascular health is unknown. To address these issues, we will conduct MySweetHeart Cohort study. The objectives are to assess the effect of GDM on offspring's cardiovascular health early in life by using surrogate markers of cardiovascular disease and atherosclerosis.

METHODS AND ANALYSIS

This is a cohort study of 100 offspring of women with GDM and 100 offspring of women without GDM. At inclusion, a baseline assessment of the mothers will be conducted through means of self-report questionnaires, a researcher-administrated interview, blood pressure and anthropometric measurements, and a maternal blood sampling. Between the 30th and 34th weeks of gestation, a foetal echography will be performed to assess the foetal cardiac structure and function, the fetomaternal circulation and the hepatic volume. At birth, maternal and neonatal characteristics will be assessed. An echocardiography will be performed to assess cardiac structure and function 2-7 days after birth; carotid intima-media thickness will be also measured to assess vascular structure. MySweetHeart Cohort is linked to MySweetHeart Trial (clinicaltrials.gov/ct2/show/NCT02890693), a randomised controlled trial assessing the effect of a multidimensional interdisciplinary lifestyle and psychosocial intervention to improve the cardiometabolic and mental health of women with GDM and their offspring. A long-term follow-up of children is planned.

ETHICS AND DISSEMINATION

Ethical approval has been obtained through the state Human Research Ethics Committee of the Canton de Vaud (study number 2016-00745). We aim to disseminate the findings through regional, national and international conferences and through peer-reviewed journals.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov (clinicaltrials.gov/ct2/show/NCT02872974).

Feasibility and reliability of carotid intima-media thickness measurements in nonsedated infants

INTRODUCTION

Carotid intima-media thickness (CIMT) is a surrogate marker for atherosclerosis. It is increased in adolescents and young adults at risk for future cardiovascular disease. However, it remains unclear if it can be considered as a surrogate marker for atherosclerosis in infancy as very few studies have been performed in infants.

OBJECTIVES

Our objective was to assess the feasibility and interobserver reproducibility of CIMT measurement in nonsedated infants.

METHODS

We measured CIMT in 81 infants less than 1 year of age. Repeated measurements were obtained by a second observer in 24 children. The analysis was performed with semiautomated edge detection software. Measurements with over 95% edge detection over a length of 1 cm were considered as valid. We further compared the measurements using the semiautomated method with measurements using the manual electronic caliper method in a subgroup of 10 infants.

RESULTS

Carotid ultrasound recordings and intima-media thickness measurements were obtained in 79% of infants (n = 64). Mean CIMT of the 64 infants measured by the first observer was 0.44 mm (SD: 0.04). In the 24 participants with measurements by two observers, the mean interobserver difference was 0.001 mm (SD: 0.026). The interobserver coefficient of variation was 5.9%. CIMT measurements obtained with the manual method (mean: 0.35; range: 0.29-0.39) were slightly lower than measurements obtained with the semiautomated method (mean: 0.38; range: 0.32-0.44). Measurements with both methods were highly correlated (r: 0.87).

CONCLUSION

Measurement of CIMT in nonsedated infants less than 1 year of age is feasible in the majority of infants with good interobserver variability.

Association Between Short-Term Systolic Blood Pressure Variability and Carotid Intima-Media Thickness in ELSA-Brasil Baseline

BACKGROUND

Blood pressure (BP) is associated with carotid intima-media thickness (CIMT), but few studies have explored the association between BP variability and CIMT. We aimed to investigate this association in the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil) baseline.

METHODS

We analyzed data from 7,215 participants (56.0% women) without overt cardiovascular disease (CVD) or antihypertensive use. We included 10 BP readings in varying positions during a 6-hour visit. We defined BP variability as the SD of these readings. We performed a 2-step analysis. We first linearly regressed the CIMT values on main and all-order interaction effects of the variables age, sex, body mass index, race, diabetes diagnosis, dyslipidemia diagnosis, family history of premature CVD, smoking status, and ELSA-Brasil site, and calculated the residuals (residual CIMT). We used partial least square path analysis to investigate whether residual CIMT was associated with BP central tendency and BP variability.

RESULTS

Systolic BP (SBP) variability was significantly associated with residual CIMT in models including the entire sample (path coefficient [PC]: 0.046; P < 0.001), and in women (PC: 0.046; P = 0.007) but not in men (PC: 0.037; P = 0.09). This loss of significance was probably due to the smaller subsample size, as PCs were not significantly different according to sex.

CONCLUSIONS

We found a small but significant association between SBP variability and CIMT values. This was additive to the association between SBP central tendency and CIMT values, supporting a role for high short-term SBP variability in atherosclerosis.

The relationship between insulin resistance and endothelial dysfunction in obese adolescents

BACKGROUND

Insulin resistance and endothelial dysfunction share a reciprocal relationship that links the metabolic and cardiovascular sequelae of obesity. We characterized the brachial artery reactivity testing (BART) and carotid artery-intima media thickness (CIMT) in adolescents categorized as obese insulin resistant (OIR) and obese not insulin resistant (ONIR). Lipoprotein particle (p) analysis and inflammatory cytokines in OIR and ONIR groups were also analyzed.

METHODS

Obese adolescents (n=40; mean body mass index [BMI] 35.6) were categorized as ONIR and OIR based on their homeostatic model assessment of insulin resistance (HOMA-IR) calculation (≤or> than 3.4). Ultrasound measured conduit arterial function BART, microvascular function (post-ischemic hyperemia) and conduit artery structure CIMT.

RESULTS

BART did not differ according to IR status (mean±SD: 7.0±4.3% vs. 5.9±3.4% in ONIR and OIR, respectively, p=0.3, but post-ischemic hyperemia was significantly greater in the ONIR group (4.5±2.2 vs. 3.5±3, p=0.04). Atherogenic lipoprotein particles; large VLDL particles and small LDL particles were higher in the OIR compared to ONIR group.

CONCLUSIONS

OIR adolescents demonstrate an inflamed atherogenic milieu compared to the ONIR adolescents. Microvascular function, but not conduit vessel structure or function, was impaired in association with IR.

Assessment of Carotid Intima-Media Thickness as an Early Marker Of Vascular Damage In Hypertensive Children

Background

The increased carotid intima-media thickness (CIMT) correlates with the presence of atherosclerosis in adults and describes vascular abnormalities in both hypertensive children and adolescents.

Objective

To assess CIMT as an early marker of atherosclerosis and vascular damage in hypertensive children and adolescents compared with non-hypertensive controls and to evaluate the influence of gender, age, and body mass index (BMI) on CIMT on each group.

Methods

Observational cohort study. A total of 133 hypertensive subjects (male, n = 69; mean age, 10.5 ± 4 years) underwent carotid ultrasound exam for assessment of CIMT. One hundred and twenty-one non-hypertensive subjects (male, n = 64; mean age, 9.8 ± 4.1 years) were selected as controls for gender, age (± 1 year), and BMI (± 10%).

Results

There were no significant difference regarding gender (p = 0.954) and age (p = 0.067) between groups. Hypertensive subjects had higher BMI when compared to control group (p = 0.004), although within the established range of 10%. Subjects in the hypertensive group had higher CIMT values when compared to control group (0.46 ± 0.05 versus 0.42 ± 0.05 mm, respectively, p < 0.001; one-way ANOVA). Carotid IMT values were not significantly influenced by gender, age, and BMI when analyzed in both groups separately (Student's t-test for independent samples). According to the adjusted determination coefficient (R²) only 11.7% of CIMT variations were accounted for by group variations, including age, gender, and BMI.

Conclusions

Carotid intima-media thickness was higher in hypertensive children and adolescents when compared to the control group. The presence of hypertension increased CIMT regardless of age, gender, and BMI.

Adolescent Cardiovascular Functional and Structural Outcomes of Growth Trajectories from Infancy: Prospective Community-Based Study

BACKGROUND

Adult BMI trajectories outperform single BMI measurements as predictors of cardiovascular mortality; however, it is unknown whether this also holds in childhood. We aimed to identify BMI trajectory categories from birth to adolescence, and examine their associations with adolescent cardiovascular function and structure.

METHODS

Adolescents from a community-based prospective birth cohort completed 11-16 BMI measurements between birth and adolescence. BMI trajectory categories were identified using latent class analysis. Associations between trajectories and cardiovascular outcomes (14 years) were assessed using adjusted linear regression models (n = 187). Cardiovascular outcomes included systolic/diastolic blood pressure, augmentation index, pulse wave velocity, carotid intima-media thickness, and retinal arteriole-to-venule ratio. Regression models were adjusted for child age, gender, height, socioeconomic status, and puberty status at outcome.

RESULTS

Three BMI trajectories emerged that diverged sharply by the age of 1 year. BMI increments were thereafter roughly parallel for those in the low normal (39%) and high normal (51%) groups, but steeper in the consistently overweight (10%) group, which was notable for lack of an obvious adiposity rebound. Cardiovascular function and structure were similar across the three trajectory groups. The only exception was augmentation index, which was 7.8% (95% CI: 2.6 to 13.0) higher in the consistently overweight individuals than the low normal individuals.

CONCLUSIONS

We found little evidence that those with consistently higher BMI from infancy experienced poorer cardiovascular function or structure by the age of 14 years. Nonetheless, childhood BMI trajectories track strongly, meaning resolution of risky BMI, while essential to decrease later cardiovascular risk, is unlikely without intervention.

Arterial stiffness in HIV-infected youth and associations with HIV-related variables

Children and young adults infected with HIV are at elevated risk for cardiovascular disease (CVD). However, scarce data exist on the utility of non-invasive methods to diagnose subclinical CVD, such as pulse wave velocity (PWV), a non-invasive measure of arterial stiffness. The objectives of this study were to assess the relationship of carotid-femoral PWV with subclinical atherosclerosis measured by carotid intima-media thickness (IMT), compare measurements to healthy controls, and evaluate variables associated with PWV in HIV-infected youth. One hundred and one 8-25 year-old subjects on stable antiretroviral therapy with low-level viremia or an undetectable HIV-1 RNA were enrolled, along with 86 healthy controls similar in age, sex and race. There was no significant difference in PWV between groups (median (Q1, Q3): 5.7 (5.2, 6.3) vs 5.7 (4.9, 6.5) m/s; P = 0.81). Among the HIV-infected subjects, PWV was positively correlated with both internal carotid artery (R = 0.31, P = 0.02) and carotid bulb IMT (R = 0.29, P = 0.01). In multivariable regression, only current alcohol consumption and systolic blood pressure were independently associated with PWV in the HIV-infected group (where current alcohol consumption and higher systolic blood pressure were associated with higher PWV); whereas, age, body mass index, and current marijuana use were associated with PWV in healthy controls. In this study of PWV in HIV-infected youth, measures of arterial stiffness were not different between subjects and controls. However, in HIV-infected youth, there was a significant association between PWV and carotid IMT, as well as between PWV and current alcohol consumption. Thus, PWV may have potential as a useful, non-invasive method to assess CVD risk in HIV-infected youth, but further investigation is needed.

Carotid artery intima-media thickness and stiffness index β changes in normal children: role of age, height and sex

AIMS

The need for early markers of atherosclerosis in paediatric ages has been emphasized recently. Few data are available on the behaviour of carotid intima-media thickness (cIMT) and arterial stiffness in normal children.

METHODS

We studied prospectively 131 healthy children (78 boys), aged 3-16 years, by high-definition ultrasonography and echo-tracking technique in order to evaluate cIMT and stiffness index β.

RESULTS

Stiffness index β underwent a significant age-related increase (P < 0.001), and a positive relationship between cIMT and height was found in boys. In addition, stiffness index β and cIMT were not related to each other (P = 0.97).

CONCLUSION

This study provides information about two markers of subclinical atherosclerosis, cIMT and carotid stiffness index β, in normal children aged 3-16 years. We found a significant age-related and height-related increase of stiffness index β in both sexes, whereas cIMT was positively related to height only in boys.

Heritability of Vascular Structure and Function: A Parent-Child Study

Background

Understanding the heritable contribution of vascular measures, from parent to offspring, may aid in risk stratification and atherosclerosis prevention efforts. We hypothesized that measures of vascular structure and function would be heritable in this cohort of parents and their adolescent offspring.

Methods and Results

High‐resolution ultrasound scans of the brachial and carotid arteries were obtained in parents (n=558) and their offspring (n=369). Lumen diameter and flow‐mediated dilation were measured in the brachial artery. Intima‐media thickness, lumen diameter, incremental elastic modulus, diameter distensibility, and cross‐sectional distensibility were measured, and carotid cross‐sectional compliance was measured in the carotid artery. Carotid–radial pulse wave velocity was obtained using SphygmoCor^®. Heritability analysis (h², expressed as %) using Sequential Oligogenic Linkage Analysis Routines was performed on the entire cohort and adjusted for age, sex, race, body–mass index, smoking, and mean arterial pressure. Data are presented as mean±SE. Measures of brachial artery diameter (h²=25±9%, P=0.001), lumen diameter (h²=55±9%, P<0.001), intima‐media thickness (h²=29±13%, P=0.014), diameter distensibility (h²=28±7%, P<0.001), cross‐sectional distensibility (h²=27±7%, P<0.001), and pulse wave velocity (h²=26±9%, P<0.001) were significantly heritable. Flow‐mediated dilation and incremental elastic modulus were not significantly heritable. Similar associations were observed in analysis restricted to siblings and complete Trios (mother, father, and child).

Conclusions

These data show that the majority of noninvasive measures of vascular structure and function are heritable, suggesting that measurement of these subclinical risk factors in parents may be helpful in assessing childhood risk for future cardiovascular disease.

Blood Pressure Trajectories From Childhood to Young Adulthood Associated With Cardiovascular Risk: Results From the 23-Year Longitudinal Georgia Stress and Heart Study

The purpose of this study is to identify subgroups of individuals with similar trajectories in blood pressure (BP) from childhood to young adulthood and to determine the relationship of BP trajectories with carotid intima-media thickness (IMT) and left ventricular mass index (LVMI). BP was measured ≤16 times during a 23-year period in 683 participants from childhood to young adulthood. IMT and LVMI were measured in 551 participants and 546 participants, respectively. Using latent class models, 3 trajectory groups in BP from childhood to young adulthood were identified, including high-increasing, moderate-increasing, and low-increasing groups. We found that trajectory of systolic BP was a significant predictor of both IMT and LVMI with increased rate of growth in systolic BP associated with higher levels of IMT and LVMI (P_{for trend} <0.001). Similar to the BP trajectory groups from childhood to young adulthood, 3 trajectory groups in BP during childhood (≤18 years) were identified, and participants in the high-increasing group had thicker IMT (P<0.001) and increased LVMI (P=0.043) in comparison with those in the low-increasing group. Results were similar for mid-BP trajectories but not for diastolic BP trajectories. Our results suggested that different BP trajectories exist from childhood to young adulthood, and the trajectories were independently associated with IMT and LVMI. We, for the first time, reported the association between systolic BP trajectories derived from childhood with subclinical cardiovascular risk in young adulthood, indicating that monitoring trajectories of BP from childhood may help identify a high cardiovascular risk population in early life.

Growth of Carotid Intima-Media Thickness in Black and White Young Adults

Background

There are few longitudinal studies that have comprehensively examined the intima‐media thickness (IMT) growth pattern and its determinants among racial population groups.

Methods and Results

Mean and maximum IMT were measured by B‐mode ultrasonography up to 3 times in 253 white and 268 black participants, aged 13 to 36 years (mean age±standard deviation 24±3.2 years old). The development of IMT was assessed using individual growth curve modeling. A total of 521 participants with 1015 IMT measurements were eligible for this study. We found higher IMT in both left and right sides in blacks compared to whites (P<0.001) in young adulthood. Both whites and blacks showed a strong linear increase in mean IMT with age. Body mass index and father's education level were associated with mean IMT, and only body mass index was associated with maximum IMT (P<0.05). We did not observe an interaction between age and race/ethnicity on the growth of IMT, suggesting that blacks and whites developed IMT in similar patterns. Interestingly, we found a faster increase in mean left‐side IMT than mean right‐side IMT (χ²=11.5, P<0.001) in both black and white subjects as well as in males and females.

Conclusions

Our findings provide compelling prospective evidence that blacks may have thicker IMT compared to whites as young adults. These racial differences could not be explained by traditional risk factors. This implies that differences in this precursor of atherosclerosis may explain racial disparity in cerebrovascular disease.

Endoglin and obestatin levels, cardiometabolic risk factors and subclinical atherosclerosis in children aged 10-18 years

BACKGROUND

The aim of this study was to investigate the early signs of atherosclerosis and to evaluate serum endoglin and obestatin levels as predictors of subclinical atherosclerosis in obese children.

METHODS

A total of 95 children (60 obese and 35 controls) aged 10-18 years were included in the study. Their endoglin and obestatin levels and biochemical parameters were measured. The carotid intima media thickness (cIMT) and brachial artery flow-mediated dilatation (FMD) responses were evaluated.

RESULTS

The cIMT values were higher (p < 0.001) and FMD responses were lower (p = 0.003) in the obese group than in the control group. A logistic regression multivariate analysis revealed that cIMT was independently associated with the body mass index (BMI) Z-score (β = 0.323, p = 0.003) and low density lipoprotein (LDL) (β = 0.29, p = 0.008), while FMD % was independently associated with waist circumference (β = -0.36, p = 0.002). The obese and control groups were similar in endoglin (p = 0.67) and obestatin levels (p = 0.70). The endoglin level was inversely correlated with the cholesterol and LDL levels (r = -0.23, p = 0.032; rho = -0.25, p = 0.019).

CONCLUSIONS

The cIMT and brachial artery FMD response in obese children are significantly different compared to healthy controls. Circulating endoglin and obestatin levels are not predictive markers for subclinical atherosclerosis in obese children aged 10-18 years old.

Noninvasive Monitoring of Immune Rejection in Face Transplant Recipients

BACKGROUND

Chronic rejection leading to allograft loss remains a significant concern after facial allotransplantation. Chronic rejection may occur without clinical signs or symptoms. The current means of monitoring is histologic analyses of allograft biopsy specimens, which is both invasive and impractical. Prior data suggest that chronic rejection is associated with changes in intima and media thickness of vessels in arms and solid organ allografts; such data have not been published for face transplant recipients.

METHODS

The authors used a 48-MHz transducer to acquire images of the bilateral facial, radial, dorsalis pedis and, if applicable, sentinel flap arteries in five face transplant recipients (8 months to 4.5 years after transplantation) and five control subjects. The authors assessed the intima, media, and adventitia thickness plus lumen and the total vessel diameter and area.

RESULTS

Face transplant recipients had thicker intima in all sites compared with controls, but the ratio of the intimal thickness of facial and radial arteries was similar in face transplant recipients compared with controls (1.00 versus 0.95; p = 0.742). Intraobserver correlation showed reliable reproducibility of the measurements (r = 0.935, p ≤ 0.001). Interobserver correlation demonstrated reproducibility of intima measurements (r = 0.422, p ≤ 0.001).

CONCLUSION

The authors demonstrate that ultrasound biomicroscopy is feasible for postsurgical monitoring, and have developed a new benchmark parameter, the facial artery-to-radial artery intimal thickness ratio, to be used in future testing in the setting of chronic rejection.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Diagnostic, IV.

Assessment of Intima-Media Thickness in Healthy Children Aged 1 to 15 Years

BACKGROUND

Carotid intima-media thickness (CIMT) has been shown to be increased in children and adolescents with traditional cardiovascular risk factors such as obesity, hypertension, and chronic kidney disease, compared with those of healthy children.

OBJECTIVE

To assess the influence of sex, age and body mass index (BMI) on the CIMT in healthy children and adolescents aged 1 to 15 years.

METHODS

A total of 280 healthy children and adolescents (males, n=175; mean age, 7.49±3.57 years; mean BMI, 17.94±4.1 kg/m2) were screened for CIMT assessment. They were divided into 3 groups according to age: GI, 1 to 5 years [n=93 (33.2%); males, 57; mean BMI, 16±3 kg/m2]; GII, 6 to 10 years [n=127 (45.4%); males, 78; mean BMI, 17.9±3.7 kg/m2], and GIII, 11 to 15 years [n=60 (21.4%); males, 40; mean BMI, 20.9±4.5 kg/m2].

RESULTS

There was no significant difference in CIMT values between male and female children and adolescents (0.43±0.06 mm vs. 0.42±0.05 mm, respectively; p=0.243). CIMT correlated with BMI neither in the total population nor in the 3 age groups according to Pearson correlation coefficient. Subjects aged 11 to 15 years had the highest CIMT values (GI vs. GII, p=0.615; GI vs. GIII, p=0.02; GII vs. GIII, p=0.004).

CONCLUSIONS

CIMT is constant in healthy children younger than 10 years, regardless of sex or BMI. CIMT increases after the age of 10 years.

Intima-Media Thickness Does Not Differ between Two Common Carotid Artery Segments in Children

Carotid intima-media thickness (cIMT) is a surrogate marker of early atherosclerotic changes in children. cIMT-studies are hard to compare, due to variations in ultrasound protocols, especially regarding the common carotid artery (CCA) segment measured in relation to the bulb. This study’s purpose was therefore to compare two distinct CCA segments in children, to see if cIMT values differ substantially according to the site of measurement. cIMT was assessed after power calculation in 30 children (15 girls) aged 8–17, using B-Mode ultrasound (5–13 MHz) at two CCA locations. The first measurement was performed over a distance of 1 cm immediately after the bulb (A), the second 1cm proximal the bulb (B) over the same distance of 1cm length. Means of end-diastolic far wall cIMT were compared between measurement A and B. cIMT in 30 participants was 0.51±0.06 mm for measurement A and 0.51±0.05 mm for measurement B. Results did not differ significantly (p = .947) over a distance of 2 cm after the bulb. According to our results, studies measuring CCA IMT within the first 2 cm, either close to the bulb or further proximal, can be compared. This will improve interpretation of data and application of reference values.

Adiposity and carotid-intima media thickness in children and adolescents: a systematic review

Background

Adiposity in childhood is associated with later cardiovascular disease (CVD), but it is unclear whether this relationship is independent of other risk factors experienced in later life, such as smoking and hypertension. Carotid-intima media thickness (cIMT) is a measure of subclinical atherosclerosis that may be used to assess CVD risk in young people. The aim of this study was to examine the relationship between adiposity and cIMT in children and adolescents.

Methods

We searched Medline, Embase, Global Health, and CINAHL Plus electronic databases (1980–2014). Population-based observational studies that reported a measure of association between objectively-measured adiposity and cIMT in childhood were included in this review.

Results

Twenty-two cross-sectional studies were included (n = 7,366 children and adolescents). Thirteen of nineteen studies conducted in adolescent populations (mean age ≥12 years, n = 5,986) reported positive associations between cIMT and adiposity measures (correlation coefficients 0.13 to 0.59). Three studies of pre-adolescent populations (n = 1,380) reported mixed evidence, two studies finding no evidence of a correlation, and one an inverse relationship between skinfolds and cIMT. Included studies did not report an adiposity threshold for subclinical atherosclerosis.

Conclusions

Based on studies conducted mostly in Western Europe and the US, adiposity does not appear to be associated with cIMT in pre-adolescents, but may be associated in adolescents. If further studies confirm these findings, a focus on cardiovascular disease prevention efforts in pre-adolescence, before arterial changes have emerged, may be justified.

Electronic supplementary material

The online version of this article (doi:10.1186/s12887-015-0478-5) contains supplementary material, which is available to authorized users.

Obesity and carotid artery remodeling

BACKGROUND/OBJECTIVE

The present study tested the hypothesis that obesity-related changes in carotid intima-media thickness (IMT) might represent not only preclinical atherosclerosis but an adaptive remodeling meant to preserve circumferential wall stress (CWS) in altered hemodynamic conditions characterized by body size-dependent increase in stroke volume (SV) and blood pressure (BP).

SUBJECTS/METHODS

Common carotid artery (CCA) luminal diameter (LD), IMT and CWS were measured in three different populations in order to study: (A) cross-sectional associations between SV, BP, anthropometric parameters and CCA LD (266 healthy subjects with wide range of body weight (24-159 kg)); (B) longitudinal associations between CCA LD and 3-year IMT progression rate (ΔIMT; 571 healthy non-obese subjects without increased cardiovascular (CV) risk); (C) the impact of obesity on CCA geometry and CWS (88 obese subjects without CV complications and 88 non-obese subjects matched for gender and age).

RESULTS

CCA LD was independently associated with SV that was determined by body size. In the longitudinal study, baseline LD was an independent determinant of ΔIMT, and ΔIMT of subjects in the highest LD quartile was significantly higher (28±3 μm) as compared with those in the lower quartiles (8±3, 16±4 and 16±3 μm, P=0.001, P<0.05 and P=0.01, respectively). In addition, CCA CWS decreased during the observational period in the highest LD quartile (from 54.2±8.6 to 51.6±7.4 kPa, P<0.0001). As compared with gender- and age-matched lean individuals, obese subjects had highly increased CCA LD and BP (P<0.0001 for both), but only slightly higher CWS (P=0.05) due to a significant increase in IMT (P=0.005 after adjustment for confounders).

CONCLUSIONS

Our findings suggest that in obese subjects, the CCA wall thickens to compensate the luminal enlargement caused by body size-induced increase in SV, and therefore, to normalize the wall stress. CCA diameter in obesity could represent an additional biomarker, depicting the impact of altered hemodynamics on arterial wall.