Brachial artery dilatation responses in healthy children and adolescents

Endothelial dysfunction in children with newly diagnosed Graves' disease

The most frequent cause of hyperthyroidism in children is Graves' disease (GD). Vascular endothelium is a specific target of thyroid hormone. The purpose of this study is to assess flow-mediated dilatation (FMD)% and serum von Willebrand factor (vWF) levels in children with newly diagnosed GD to reflect the extent of endothelial dysfunction in those children. In this study, 40 children with newly discovered GD and 40 children who were healthy served as the control group. Both patients and controls had anthropometric assessment, as well as measurements of fasting lipids, glucose, insulin, high-sensitivity C-reactive protein (hs-CRP), TSH, and free thyroxine (FT4 and FT3), thyrotropin receptor antibodies TRAbs and vWF. Noninvasive ultrasound was utilized to quantify the carotid arteries' intima-media thickness and the brachial artery's FMD. Patients reported significantly reduced FMD response and greater vWF and hs-CRP levels compared to controls (P = 0.001 for each). In multivariate analysis, we reported that vWF was significantly correlated with TSH (OR 2.5, 95% CI 1.32-5.32, P = 0.001), FT3 (OR 3.4, 95% CI 1.45-3.55, P = 0.001), TRAb (OR 2.1, 95% CI 1.16-2.23, P = 0.01), and FMD% (OR 4.2, 95% CI 1.18-8.23, P = 0.001).  Conclusions: Children with newly diagnosed GD have endothelial dysfunction, which is shown by impaired FMD and increased vWF. These findings support the idea that GD may need to be treated as soon as possible. What is Known: • Graves' disease is the most common cause of hyperthyroidism in children. • vWF is a reliable marker for detection of vascular endothelial dysfunction. What is New: • Children with newly diagnosed Graves' disease may have endothelial dysfunction as reflected by impairment of FMD and raised vWF level. • Measurement of vWF level in children with newly diagnosed Graves' disease can be used for early detection of endothelial dysfunction.

Early Markers of Atherosclerosis in Children and Adolescents with Type 1 Diabetes Mellitus

OBJECTIVES

To detect early atherosclerosis changes using flow-mediated dilation (FMD) of the brachial artery, carotid intima-media thickness (CIMT), inflammatory markers (hs-CRP, IL-6), and endothelial markers (sICAM and sVCAM).

METHODS

The authors recruited 4 to 18-y-old children with type 1 diabetes mellitus (T1DM) and age- and sex-matched normal children, excluding those with familial hypercholesterolemia, syndromic disorders, and cardiovascular disease. CIMT and FMD were measured in both the groups. Biomarkers hs-CRP, IL-6, sICAM, and sVCAM, were analyzed in the T1DM group.

RESULTS

Forty T1DM children and 40 controls with 27 (67.5%) girls were enrolled in each group. The mean age was 9.68 y. The T1DM group had 4 (10%) obese and 4 (10%) overweight children. Among cases, 9 (22.5%) had diabetes for > 5 y, 24 (60%) required daily insulin between 0.8 and 1.2 IU/kg/d and 26 (65%) had HbA1c > 10 g/dL. The CIMT values were significantly higher in cases (0.69 mm) than in controls (0.59 mm); 29 (72.5%) cases had abnormal combined CIMT values. FMD was lesser in cases than in controls but not significant. The median values of hs-CRP, IL-6, sICAM, sVCAM were 0.81 mg/L, 6.27 pg/mL, 46.33 ng/mL and 668.81 ng/mL, respectively. A significant correlation of IL-6 with CIMT (r = 0.543, p =  < 0.001) and sICAM with FMD (r =  -0.397, p = 0.011) was observed. VCAM was low in the obese and overweight children.

CONCLUSION

Children with type 1 diabetes had higher CIMT than normal children, whereas FMD did not differ. The association between elevated inflammatory markers with high CIMT and low FMD indicates that inflammation plays an essential role in endothelial dysfunction.

The effect of different intensity physical activity on cardiovascular metabolic health in obese children and adolescents: An isotemporal substitution model

Objective: This study's purpose was to investigate the effects of different intensities of physical activity on cardiovascular metabolism in obese children and adolescents based on an isochronous replacement model. Methods: A total of 196 obese children and adolescents (mean age, 13.44 ± 1.71 years) who met the inclusion criteria and attended a summer camp from July 2019 to August 2021 were recruited for this study, and all subjects wore a GT3X + triaxial motion accelerometer uniformly around the waist to record physical activity levels. We collected the subjects' height, weight, and cardiovascular risk factors such as waist circumference, hip circumference, fasting lipids, blood pressure, fasting insulin, and fasting glucose before and after 4 weeks of camp and constructed cardiometabolic risk score (CMR-z). We analyzed the effects of different intensities of physical activity on cardiovascular metabolism in obese children using isotemporal substitution model (ISM). Results: After 4 weeks, cardiovascular risk factors such as body weight, waist circumference, triglyceride, and total cholesterol were reduced in adolescents with obesity (p <0.01), and CMR-z was also reduced (p <0.01). ISM analysis revealed that all sedentary behavior (SB) replacement with 10 min of light physical activity (LPA) reduced CMR-z [β = -0.10, 95% CI (-0.20, -0.01)]; 10-min of moderate physical activity (MPA) replacement of SB reduced CMR-z [β = -0.32, 95% CI (-0.63, -0.01)]; 10-min of vigorous physical activity (VPA) replacement of SB reduced CMR-z [β = -0.39, 95% CI (-0.66, -0.12)]. Conclusion: Replacement of SB with 10 min of LPA, MPA, and VPA were all effective in improving cardiovascular risk health, respectively, but MPA or VPA was more effective.

Utility of Epicardial Fat Thickness in Subclinical Hypothyroid Children to Determine Existence of Subclinical Atherosclerosis in Them

Context

Adult studies have shown the association of subclinical hypothyroid (SCH) with various cardiovascular dysfunction, which indicates SCH may be a potentially modifiable risk factor of CV disease and mortality. However, there is still controversy about the association of cardiovascular dysfunction in children with SCH. Epicardial fat thickness (EFT) is a reliable and sensitive marker of cardiovascular risk and has become an emerging modality to predict CV risks.

Aims

To measure the EFT in children with subclinical hypothyroidism and compare with healthy children. To find its correlation with subclinical atherosclerosis. To compare EFT between TPO positive and TPO negative subclinical hypothyroid patients.

Materials and Methods

Children of subclinical hypothyroidism (TSH >5 mIU/ml with normal FT3, FT4, and age and sex matched control were included as per inclusion and exclusion criteria. Clinical data was collected from all study subjects. Thyroid function tests including FT3, FT4 and TSH, TPO antibody, fasting insulin, hsCRP, Lp(a), USG neck for carotid intima media thickness (CIMT), USG brachial artery for flow mediated dilation (FMD) and echocardiography for epicardial fat thickness (EFT) were done in all patients.

Results

A total 42 number of SCH and 50 age and sex matched controls were recruited and screened for various parameters of subclinical atherosclerosis. EFT was significantly higher in the cases than in the controls (6.27 mm vs 4.54 mm) with P value < 0.001. Brachial FMD was significantly lower in cases than the cohort (4.5% vs 8.93%, P < 0.001). Difference in CIMT was not significant amongst the cases and controls. EFT failed to correlate with the level of TSH though it had significant positive correlation with hsCRP. The patients who were TPO positive, had higher fasting insulin, HOMAIR, hsCRP, Lp(a) than those who were TPO negative.

Conclusion

Results of this study show the presence of subclinical atherosclerosis in children with SCH regardless of the aetiologies. The patients of Hashimoto thyroiditis had significantly high insulin resistance and inflammation than the SCH patients of other aetiologies.

Association of Epicardial Fat with Diastolic and Vascular Functions in Children with Type 1 Diabetes

We aimed to examine the relationship between epicardial fat thickness (EFT) measured by echocardiography and cardiovascular functional parameters in children with type 1 diabetes mellitus (T1DM). The study included 50 type 1 diabetic children and 50 healthy subjects matched by sex, age, and body mass index. In addition to laboratory tests, all participants underwent transthoracic echocardiography for EFT, cardiac dimensions and left ventricular functions, and ultrasonographic examination for brachial artery flow-mediated dilation (FMD) response and carotid intima-media thickness (CIMT). Multivariate linear regression was used to analyze the relationship between EFT and CIMT, FMD, lateral mitral E' velocity, and mitral E/E' ratio. EFT was significantly increased in diabetic children compared with controls (P < 0.001). In comparison with controls diabetic children had significantly increased mitral A, decreased lateral mitral E', decreased mitral E/A ratio, decreased lateral mitral E'/A' ratio, and increased mitral E/E' ratio (P < 0.001). FMD response was significantly lower in diabetic group versus controls (P < 0.001) and CIMT was significantly increased in diabetics versus controls (P = 0.03). EFT was negatively correlated with lateral mitral E' velocity (r =  - 0.613, P < 0.001), positively correlated with mitral E/E' ratio (r = 0.60, P < 0.001), positively correlated with CIMT (r = 0.881, P < 0.001), and negatively correlated with FMD (r =  - 0.533, P < 0.001). By multivariate regression analysis, the EFT was independently and positively associated with CIMT mean and E/E' mean and negatively associated with FMD mean and E' mean. The cut-off point for EFT as predictor of endothelial dysfunction was 6.95 mm. Our findings suggest that children with T1DM have subclinical LV diastolic and vascular endothelial dysfunctions associated with increased EFT.

Endothelial Dysfunction in Childhood Cancer Survivors: A Narrative Review

Assessment of endothelial dysfunction in cancer survivors may have a role in the early identification of non-communicable diseases and cardiovascular late effects. Oncological therapies may impair endothelial function. Therefore, in patients such as childhood cancer survivors who could benefit from early cardioprotective pharmacological interventions, it is essential to monitor endothelial function, even if the optimal methodology for investigating the multifaceted aspects of endothelial dysfunction is still under debate. Biochemical markers, as well as invasive and non-invasive tools with and without pharmacological stimuli have been studied. Human clinical studies that have examined lifestyle or cancer treatment protocols have yielded evidence showing the involvement of lipid and lipoprotein levels, glycemic control, blood pressure, adiposity, inflammation, and oxidative stress markers on the state of endothelial health and its role as an early indicator of cardiometabolic risk. However, with regards to pharmacological interventions, cautious interpretation of the result attained whilst monitoring the endothelial function is warranted due to methodological limitations and substantial heterogeneity of the results reported in the published studies. In this narrative review, an overview of evidence from human clinical trials examining the effects of cancer therapies on endothelial disease is provided together with a discussion of endothelial function assessment using the different non-invasive techniques available for researchers and clinicians, in recent years.

Risk Assessment and Clinical Management of Children and Adolescents with Heterozygous Familial Hypercholesterolaemia. A Position Paper of the Associations of Preventive Pediatrics of Serbia, Mighty Medic and International Lipid Expert Panel

Heterozygous familial hypercholesterolaemia (FH) is among the most common genetic metabolic lipid disorders characterised by elevated low-density lipoprotein cholesterol (LDL-C) levels from birth and a significantly higher risk of developing premature atherosclerotic cardiovascular disease. The majority of the current pediatric guidelines for clinical management of children and adolescents with FH does not consider the impact of genetic variations as well as characteristics of vascular phenotype as assessed by recently developed non-invasive imaging techniques. We propose a combined integrated approach of cardiovascular (CV) risk assessment and clinical management of children with FH incorporating current risk assessment profile (LDL-C levels, traditional CV risk factors and familial history) with genetic and non-invasive vascular phenotyping. Based on the existing data on vascular phenotype status, this panel recommends that all children with FH and cIMT ≥0.5 mm should receive lipid lowering therapy irrespective of the presence of CV risk factors, family history and/or LDL-C levels Those children with FH and cIMT ≥0.4 mm should be carefully monitored to initiate lipid lowering management in the most suitable time. Likewise, all genetically confirmed children with FH and LDL-C levels ≥4.1 mmol/L (160 mg/dL), should be treated with lifestyle changes and LLT irrespective of the cIMT, presence of additional RF or family history of CHD.

Sedentary Behavior in Childhood, Lower Arterial Compliance and Decreased Endothelial Function-Cross Sectional Data From a German School Cohort

BACKGROUND

Endothelial function by flow-mediated dilatation assesses early markers of atherosclerotic progression. Greater amounts of physical activity and physical fitness in children are associated with cardiovascular health benefits. We aimed to explore factors, influencing endothelial function and arterial compliance in a cohort of healthy school children.

METHODS

The 94 participants (41 girls, 53 boys) in the study were young, healthy children from a German school cohort. Anthropometric data, body composition and blood pressure were assessed. Blood was drawn (8 h overnight fast), assessing total cholesterol, high density lipoprotein and low density lipoprotein and triglycerides. Endothelial function was diagnosed by flow-mediated dilatation with ultrasonography (ALOKA/Hitachi, Prosound alpha 6). Tracking gates were set on the intima in B-mode. The waveform of diameter changes over the cardiac cycle was displayed in real time using the FMD-mode of the eTRACKING system. Changes in arterial diameter at baseline, ischaemia and vasodilatation were measured. A symptom limited pulmonary exercise test on a bicycle ergometer was performed to test cardiorespiratory fitness. Physical activity was assessed using GT3x accelerometers (Actigraph, USA), over 4 days (including 1 week-end day), with a minimum wear-time duration of 10 h.

RESULTS

The median age was 12.2 years (11.8-12.8). Children were normal weight, blood lipid profiles (cholesterol, high-density lipoprotein, low-density lipoprotein, triglyceride) were in normal range. Baseline measurements during the diagnostics of endothelial function revealed higher arterial compliance of the brachial artery in boys. Boys' cardiorespiratory fitness was higher than compared to girls. Boys met the recommendations of 60 min moderate to vigorous activity, whereas girls were significantly less active and did not meet current recommendations. More time spent in sedentary activity was the main predictor for lower arterial compliance (adjusted for age and sex), accounting for 14% of the variance. No significant model revealed, analyzing the influencing factors such as anthropometric data, blood lipids, physical activity and fitness on endothelial function.

CONCLUSION

This is the first study on endothelial function in association to objectively measured physical activity and cardiorespiratory fitness in healthy school children in Germany. The study highlights the importance of reducing time spent being sedentary to maintain endothelial health.

Adolescent Obesity: Diet Quality, Psychosocial Health, and Cardiometabolic Risk Factors

Obesity is a multifaceted chronic condition with several contributing causes, including biological risk factors, socioeconomic status, health literacy, and numerous environmental influences. Of particular concern are the increasing rates of obesity in children and adolescents, as rates of obesity in youth in the United States have tripled within the last three decades. Youth from historically disadvantaged backgrounds tend to have higher rates of obesity compared to other groups. Adolescents often do not meet intake recommendations for certain food groups and nutrients, which may contribute to a heightened risk of obesity. With obesity disproportionately affecting adolescents (ages 12–19 years), negative effects of excess adiposity may be particularly salient during this critical period of development. The presentation of chronic cardiometabolic disease symptoms typically observed in adults, such as hypertension, hyperglycemia, dyslipidemia, and inflammation, are becoming increasingly common in adolescents with obesity. Additionally, there is dynamic interplay between obesity and psychosocial health, as adolescents with obesity may have increased levels of stress, depressive symptoms, and reduced resilience. To reduce and prevent adolescent obesity, the implementation of theory-driven multicomponent school- and community-based interventions have been suggested. These interventions promote knowledge and self-efficacy for healthful practices that have the potential to progress to sustained behavior change.

Higher values of triglycerides:HDL-cholesterol ratio hallmark disease severity in children and adolescents with sickle cell anemia

Dyslipidemia has been described in sickle cell anemia (SCA) but its association with increased disease severity is unknown. Here, we examined 55 children and adolescents with SCA as well as 41 healthy controls to test the association between the lipid profiles in peripheral blood and markers of hemolysis, inflammation, endothelial function, and SCA-related clinical outcomes. SCA patients exhibited lower levels of total cholesterol (P<0.001), low-density lipoprotein cholesterol (LDL-c) (P<0.001), and high-density lipoprotein cholesterol (HDL-c) (P<0.001), while displaying higher triglyceride (TG) levels and TG/HDL-c ratio values (P<0.001). TG/HDL-c values were positively correlated with lactate dehydrogenase (P=0.047), leukocyte count (P=0.006), and blood flow velocity in the right (P=0.02) and left (P=0.05) cerebral artery, while being negatively correlated with hemoglobin levels (P<0.04). Acute chest syndrome (ACS) and vaso-occlusive events (VOE) were more frequent in SCA patients exhibiting higher TG/HDL-c values (odds ratio: 3.77, P=0.027). Multivariate logistic regression analysis confirmed independent associations between elevated TG/HDL-c values and SCA. Thus, children and adolescents with SCA exhibited a lipid profile associated with hemolysis and inflammatory parameters, with increased risk of ACS and VOE. TG/HDL-c is a potential biomarker of severity of disease.

Hidden hearing loss in children and adolescents with sickle cell anemia

OBJECTIVE

To evaluate the auditory system for hidden hearing loss (HHL) and its association with clinical variables and endothelial dysfunction (ED) in children and adolescents with sickle cell anemia (SCA).

METHODS

Participants included 37 patients with stable SCA and 44 healthy controls (HC group) (aged 6-18 years) with hearing thresholds ≤ 20 dB (dB) were evaluated for pure tone audiometry, tympanometry, acoustic reflex, otoacoustic emission, and auditory evoked potentials. Laboratory analysis of the lipid profile, and C-reactive protein levels and endothelial function using ultrasonographic imaging of the brachial artery to assess flow-mediated dilation were performed.

RESULTS

The SCA group presented with a higher rate of increased contralateral acoustic reflex thresholds, compared to those in the HC group at all frequencies and in both ears (p < 0.05). There were significant differences in the brainstem auditory evoked potentials between the SCA and HC groups. In the SCA group, the waves III and V latencies were increased (p = 0.006 and 0.004 respectively), and the I-III and I-V interpeak intervals were longer (p = 0.015 and 0.018 respectively) than those in the HC group. There was no association between the audiological measures and clinical and metabolic variables and sickle cell anemia complications including endothelial function and therapy.

CONCLUSION

In conclusion, our findings suggest that damage in the auditory system in SCA patients can be present involving retrocochlear structures, causing functional deficits without deterioration of auditory sensitivity.

Associations of sex, age and adiposity in endothelium-independent dilation in children

OBJECTIVE

To examine the association of age, sex, and obesity status on endothelial-independent dilation (EID) among children and adolescents.

STUDY DESIGN

This study examined 264 children (143 males) between 8 to 18 years old (mean  ±  SD: age  =  14.3  ±  2.7 years). Endothelial-independent dilation was assessed via ultrasound imaging of the brachial artery following administration of 0.3 milligrams of sublingual nitroglycerin. A one-way analysis of variance with Bonferroni post hoc comparisons assessed sex-differences in percent peak EID dilation (EID%-peak) and EID area under the curve (EID%-AUC), while analysis of covariance (ANCOVA) adjusted for race, age, body mass index percentile (BMI-percentile), and brachial artery diameter. Multiple linear regression evaluated the association of sex, age, BMI-percentile, percent body fat (%BF), and brachial artery diameter on EID.

RESULTS

Prior to adjustment, EID%-peak was significantly higher among females than males (mean  ±  SE: 26.9  ±  0.5% versus 22.9  ±  0.6%, p  <  0.001, respectively); similar findings for EID%-AUC (4214%  ±  105%·s versus 3398%  ±  97%·s, p  <  0.001) were observed. After adjusting for covariates, EID%-AUC remained consistent (p  =  0.03) while EID%-peak was not significantly different between sexes (p  =  0.21). EID%-peak was significantly higher among normal weight compared to obese participants (p  =  0.04), while no differences were observed between obesity status after adjustment for brachial artery diameter (p  =  0.64). Both unadjusted (p  =  0.16) and adjusted EID%-AUC (p  =  0.24) was not significantly different between obesity status. BMI-percentile was not associated with EID%-peak (p  =  0.76) or EID%-AUC (p  =  0.30). Additionally, %BF was not associated with EID%-peak (p  =  0.56) or EID%-AUC (p  =  0.15). After adjusting for brachial artery diameter, BMI-percentile, and age, males had lower EID%-AUC (p  =  0.03) and lower but not significant EID%-peak (p  =  0.21).

SIGNIFICANCE

Vascular smooth muscle function was significantly lower among male children and adolescents, which is suggestive that impaired EID and increased cardiovascular disease risk among males may begin in childhood. Interestingly, obesity status and BMI-percentile was not associated with EID in children and adolescents after adjusting for brachial artery diameter.

The effect of an apple polyphenol extract rich in epicatechin and flavan-3-ol oligomers on brachial artery flow-mediated vasodilatory function in volunteers with elevated blood pressure

BACKGROUND

The primary aim of this study was to test the hypothesis that an orally ingested apple polyphenol extract rich in epicatechin and flavan-3-ol oligomers improves endothelium-dependent brachial artery flow-mediated vasodilatation (FMD) in volunteers with borderline hypertension. The secondary aim of the study was to test whether the investigational product would improve endothelium-independent nitrate-mediated vasodilatation (NMD).

METHODS

This was a single centre, repeated-dose, double-blind, placebo-controlled, crossover study in 60 otherwise healthy subjects (26 men, 34 women; aged 40-65 years) with borderline hypertension (blood pressure 130-139/85-89 mmHg) or unmedicated mild hypertension (blood pressure 140-165/90-95 mmHg). The subjects were randomised to receive placebo or the apple polyphenol extract to provide a daily dose of 100 mg epicatechin for 4 weeks, followed by a four to five-week wash-out period, and then 4 weeks intake of the product that they did not receive during the first treatment period. FMD and NMD of the left brachial artery were investigated with ultrasonography at the start and end of both treatment periods, and the per cent increase of the arterial diameter (FMD% and NMD%) was calculated.

RESULTS

With the apple extract treatment, a significant acute improvement was detected in the mean change of maximum FMD% at the first visit 1.16 (p = 0.04, 95% CI: 0.04; 2.28), last visit 1.37 (p = 0.02, 95% CI: 0.22; 2.52) and for both visits combined 1.29 (p < 0.01, 95% CI: 0.40; 2.18). However, such improvement was not statistically significant when apple extract was compared with placebo. The overall long-term effect of apple extract on FMD% was not different from placebo. No statistically significant differences between the apple extract and placebo treatments were observed for endothelium-independent NMD.

CONCLUSIONS

A significant acute improvement in maximum FMD% with apple extract administration was found. However, superiority of apple extract over placebo was not statistically significant in our study subjects with borderline hypertension or mild hypertension. The study raised no safety concerns regarding the daily administration of an apple polyphenol extract rich in epicatechin.

TRIAL REGISTRATION

The trial is registered at http://clinicaltrials.gov (identifier: NCT01690676 ). Registered 25th May 2012.

Sleep-disordered breathing is associated with blood pressure and carotid arterial stiffness in obese children

INTRODUCTION

Both sleep-disordered breathing (SDB) and high blood pressure (BP) occur more frequently among obese children than among normal weight children, and this may be due to endothelial dysfunction and worsened arterial stiffness. The aim of this study was to evaluate the possible association between SDB and BP, and the possible role of endothelial function and local and systemic arterial stiffness in a sample of obese children asymptomatic for sleep disturbances.

MATERIALS AND METHODS

Thirty-nine obese children were included in the study. Children underwent overnight limited channel polysomnography, and the vascular measurements included the following: office and 24-h ambulatory BP; brachial flow-mediated dilatation, carotid intima-media thickness and carotid distensibility measured using ultrasound; and systemic arterial stiffness index measured using digital volume pulse analysis.

RESULTS

Significant correlations between different BP measurements (both office and ambulatory BP monitoring and estimated by Z score) and SDB were found, including correlations involving the respiratory disturbance index, the apnea-hypopnea index (AHI), the number of desaturations per hour and the mean peripheral saturation (r ranging between 0.330 and 0.474). Carotid distensibility was correlated with the AHI (r = -0.367; P = 0.030) and with the mean oxygen saturation (r = 0.401; P = 0.017). In contrast, there was no relationship among flow-mediated dilatation, stiffness index, carotid intima-media thickness and all the tested respiratory markers. In the multivariate analysis, the supine Z SBP remained independently associated with the number of desaturations per hour and the AHI, even after correction for carotid distensibility and BMI.

CONCLUSION

Our data suggest that in obese children asymptomatic for sleep respiratory problems, SDB might worsen BP, in part, through an increase in arterial stiffness.

Methods to evaluate arterial structure and function in children - State-of-the art knowledge

BACKGROUND

With increasing rates of hypertension, obesity, and diabetes in the pediatric population, wide available, and reproducible methods are necessary to evaluate arterial structure and function in children and adolescents.

METHODS

MEDLINE/Pubmed was searched for articles published in years 2012-2017 on methodology of, current knowledge on, and limitations of the most commonly used methods to evaluate central, proximal and coronary arteries, as well as endothelial function in pediatric patients.

RESULTS

Among 1528 records screened (including 1475 records from years 2012 to 2017) 139 papers were found suitable for the review. Following methods were discussed in this review article: ultrasound measurements of the intima-media thickness, coronary calcium scoring using computed tomography, arterial stiffness measurements (pulse wave velocity and pulse wave analysis, carotid artery distensibility, pulse pressure, and ambulatory arterial stiffness index), ankle-brachial index, and methods to evaluate vascular endothelial function (flow-mediated vasodilation, peripheral arterial tonometry, Doppler laser flowmetry, and cellular and soluble markers of endothelial dysfunction).

CONCLUSIONS

Ultrasonographic measurement of carotid intima-media thickness and measurement of pulse wave velocity (by oscillometry or applanation tonometry) are highly reproducible methods applicable for both research and clinical practice with proved applicability for children aged ≥6 years or with height ≥120cm. Evaluation of ambulatory arterial stiffness index by ambulatory blood pressure monitoring is another promising option in pediatric high-risk patients. Clearly, further studies are necessary to evaluate usefulness of these and other methods for the detection of subclinical arterial damage in children.

Associations between endothelial dysfunction and clinical and laboratory parameters in children and adolescents with sickle cell anemia

Background

Hematological changes can drive damage of endothelial cells, which potentially lead to an early endothelial dysfunction in patients with sickle cell anemia (SCA). An association may exist between endothelial dysfunction and several clinical manifestations of SCA. The present study aims to evaluate the links between changes in endothelial function and clinical and laboratory parameters in children and adolescents with SCA.

Methods

This study included 40 children and adolescents with stable SCA as well as 25 healthy children; aged 6–18 years. All study subjects were evaluated for endothelial function using Doppler ultrasonography. In addition, a number of laboratory assays were performed, including reticulocyte and leukocyte counts as well as measurement of circulating levels of total bilirubin, C-reactive protein (CRP), glucose, lipoproteins and peripheral oxyhemoglobin saturation. These parameters were also compared between SCA patients who were undertaking hydroxyurea (HU) and those who were not.

Results

Flow-mediated vasodilation (FMD) values were found to be reduced in SCA patients compared with those detected in healthy controls. SCA individuals with lower FMD values exhibited higher number of hospital admissions due to vaso-occlusive events. Additional analyses revealed that patients who had decreased FMD values exhibited higher odds of acute chest syndrome (ACS) episodes. A preliminary analysis with limited number of individuals failed to demonstrate significant differences in FMD values between SCA individuals who were treated with HU and those who were not.

Conclusions

Children and adolescents with SCA exhibit impaired endothelial function. Reductions in FMD values are associated with ACS. These findings underline the potential use of FMD as screening strategy of SCA patients with severe prognosis at early stages.

Children With Type 1 Diabetes Have Delayed Flow-Mediated Dilation

OBJECTIVES

Children with type 1 diabetes have accelerated atherosclerosis with early endothelial dysfunction as measured by reduced flow-mediated dilation (FMD) at 60 seconds postischemic stress (early FMD). Delayed dilation may also occur in the presence of cardiovascular risk factors and may be a more sensitive marker. No data exist that evaluate FMD beyond 60 seconds (delayed FMD) in children with type 1 diabetes. We aimed to compare early and delayed FMD in children with type 1 diabetes and in healthy children.

METHODS

We studied 66 children 13.5±2.8 years of age; 29 were males. Of the 66 children, 38 had type 1 diabetes, and 28 were healthy age- and gender-matched controls. Evaluation of brachial artery FMD was performed at 60 seconds (FMD_60s) and 120 seconds (FMD_120s) postischemic stress. Early FMD was defined as peak FMD_60s and delayed FMD as peak FMD_120s. RESULTS: Children with type 1 diabetes had diabetes durations of 5.4±4.6 years and median glycated hemoglobin levels of 8.8 (6.6 to 14)% (73 [49 to 130] mmol/mol). Of the children, 8 with type 1 diabetes and 1 healthy child had delayed FMD; a relationship was seen between the prevalence of early FMD and delayed FMD in children with type 1 diabetes and healthy children, respectively (p=0.019). Children with type 1 diabetes and delayed FMD had lower FMD_60s than children without delayed FMD (2.50±3.61 vs. 6.14±3.83 percentage units; p=0.02). Children with type 1 diabetes had lower FMD_60s than healthy children (5.38±4.0 percentage units; p=0.03) but not FMD_120s (7.56±3.5 percentage units; p=0.47).

CONCLUSIONS

Delayed FMD patterns occur in children with type 1 diabetes and detect children who have more severe vascular abnormalities. The standard FMD_60s remains the better marker to identify children at increased risk for cardiovascular disease.

Endothelial Dysfunction, Distensibility and Intima-media Thickness and Aetiology of Stroke

This study measured carotid artery distensibility, intima-media thickness (IMT) and flow-mediated dilatation (FMD) in patients with ischaemic stroke and evaluated if there was a relationship between these measurements and the presence of atrial fibrillation. Distensibility and IMT were measured in 89 patients with ischaemic stroke using ultrasonography; 44 patients had atrial fibrillation. Distensibility was determined using the Reneman equation. FMD was measured in a second group of 52 patients with ischaemic stroke; 20 patients had atrial fibrillation. Patients with atrial fibrillation had lower IMT values compared with patients without atrial fibrillation (0.67 versus 0.79 mm, respectively). Distensibility increased in patients with atrial fibrillation compared with patients without atrial fibrillation (0.19 versus 0.10 mm/100 mmHg, respectively). Patients with atrial fibrillation had significantly better FMD results than patients without atrial fibrillation (5.7% versus 3.2%, respectively). Measuring distensibility, IMT and FMD might be helpful in differentiating between stroke of embolic and thrombotic aetiology.

Impact of Disease Duration on Vascular Surrogates of Early Atherosclerosis in Childhood-Onset Systemic Lupus Erythematosus

OBJECTIVE

To determine whether longer disease duration negatively impacts carotid intima-media thickness (CIMT), flow-mediated dilation (FMD), and pulse wave velocity (PWV) in a cohort of patients with childhood-onset systemic lupus erythematosus (SLE), and to compare CIMT, FMD, and PWV in patients with childhood-onset SLE with those in healthy children and explore determinants of vascular test results in childhood-onset SLE.

METHODS

Cross-sectional analysis was performed in a prospective longitudinal cohort of patients with childhood-onset SLE at the latest followup visit. Clinical and laboratory data were collected for patients with childhood-onset SLE. CIMT, FMD, and PWV were measured using standardized protocols in patients with childhood-onset SLE and healthy children. Correlations between disease duration and results of the 3 vascular tests were performed. Vascular data in patients with childhood-onset SLE were compared with those in healthy children. Multivariable linear regression was used to identify determinants of CIMT, FMD, and PWV in childhood-onset SLE.

RESULTS

Patients with childhood-onset SLE (n = 149) and healthy controls (n = 178) were enrolled. The median age of the patients was 17.2 years (interquartile range [IQR] 15.7-17.9 years), and their median disease duration was 3.2 years (IQR 1.8-4.9 years). The median age of the healthy children was 14.7 years (IQR 13.1-15.9 years). Longer disease duration correlated with worse FMD (r = -0.2, P = 0.031) in patients with childhood-onset SLE. Patients with childhood-onset SLE had smaller (better) CIMT, higher (better) FMD, and similar PWV compared with healthy controls. Linear regression analysis explained <24% of the variation in vascular test results in patients with childhood-onset SLE, suggesting that other variables should be explored as important determinants of CIMT, FMD, and PWV.

CONCLUSION

In this cohort of 149 patients with childhood-onset SLE, patients did not have worse CIMT, FMD, or PWV than did healthy controls. Longer disease duration was associated with worse FMD, suggesting progressive endothelial dysfunction over time.

Peak shear and peak flow mediated dilation: a time-course relationship

PURPOSE

To explore the temporal relationship between brachial artery peak shear stress (Shear) and flow-mediated dilation (FMD) in children and adults.

METHODS

Shear and brachial artery diameter were tracked following reactive hyperemia in 122 children and 350 adults using sonographic imaging.

RESULTS

Peak Shear, Shear area under the curve (Shear(AUC)), and Peak FMD were significantly larger in children than in adults. The time to peak Shear (Shear(TTP)) and time to peak FMD (FMD(TTP)) were significantly lower in children, while there was no significant difference in time from Shear(TTP) to FMD(TTP) between children and adults.

CONCLUSIONS

Children have a lower shear stimulus and FMD response than adults, but the time interval separating these events is similar. These differences could be due to changes in vascular dynamics with age, including reduced smooth muscle cell responsiveness and other factors. Despite differences in timing, the interval from peak Shear to peak FMD was similar in children and adults.

Varying patterns of brachial artery flow-mediated dilatation in women with polycystic ovary syndrome and controls: An application of the group-based trajectory modeling

PURPOSE

To identify changing patterns of absolute change in brachial artery lumen diameter (LD) after reactive hyperemia in women with polycystic ovary syndrome (PCOS) and controls and to quantify the association of PCOS status and participants' factors with these patterns.

METHODS

Brachial flow-mediated dilation was measured in 128 women with PCOS and 148 controls aged 30-60 years. Group-based trajectory modeling was used to investigate absolute change in LD every 30 seconds for 2 minutes after occluding cuff deflation. Multinomial logistic regression was used to identify factors associated with trajectories.

RESULTS

Three patterns emerged, namely nondilators (42.2%), dilators (44.6%), and enhanced dilators (13.0%). The proportion of women with PCOS did not differ across groups. Independently of age and PCOS status, larger baseline LD (odds ratio; 95% confidence interval: 2.51; 1.29, 4.89) and lower insulin levels (0.70; 0.52, 0.93) were associated with nondilators rather than with dilators. Higher total cholesterol was associated with dilators in women with PCOS but with nondilators in controls.

CONCLUSIONS

Trajectory modeling identified distinct patterns of change in LD and factors associated with the endothelial response. This method may be a useful tool to understand the brachial flow-mediated vasodilator response.

Flow-mediated dilatation, using time course data, shows maturation of the brachial artery from young children to mid-adolescents

Flow-mediated dilatation (FMD) is a tool widely used to measure arterial responsiveness to sheer stress. However, there is scant literature to show how the peripheral arterial response changes as the vascular system matures. One reason for this is that the feasibility of measuring FMD in younger children has not been established. The aim of the present study was to assess brachial artery function at rest and during the FMD response after 4 min ischaemia of the forearm in children aged 6-15 years. Time to reach maximum FMD (FMDmax ) was found to be correlated with age (r = 0.4, P < 0.05), resting brachial artery diameter (r = 0.4, P < 0.05), height (r = 0.4, P < 0.05), body mass index (BMI; r = 0.45, P < 0.05), body surface area (r = 0.44, P < 0.05) and resting blood flow (r = 0.37, P < 0.05). However, there was no correlation between the traditional FMD response at 60 s or FMD maximal dilation and age, resting brachial artery diameter, height, weight, BMI, body surface area and resting blood flow. In conclusion, the time taken to reach the maximal dilation response is related to age, brachial artery luminal diameter and body habitus, but not the traditional measure of FMD response at 60 s or the maximal dilatation percentage.

Increased arterial stiffness in South Dakota American Indian children

Arterial stiffness has been observed in white American obese children, yet there are no data in American Indian youth, who are affected disproportionately by the cardiovascular consequences of childhood obesity and its accompanying risk factors. The purpose of this study was to determine the association of childhood overweight-obesity and cardiometabolic risk factors with arterial stiffness in South Dakota white American and American Indian children. Thirty-six (28 white American and 8 American Indian) children (age, 13 ± 1 years; grades 6-8) from a rural South Dakota elementary and middle school were studied: 18 had a healthy weight (body mass index (BMI), 19.5 ± 1.9 kg/m(2)) and 18 were overweight-obese (BMI, 26.8 ± 3.5 kg/m(2)). Arterial stiffness was assessed using applanation tonometry via pulse wave analysis to determine carotid-radial pulse wave velocity (crPWV) and aortic augmentation index (AIx). There were no differences (P = 0.94) in crPWV between healthy weight (7.1 ± 1.4 m/s) and overweight-obese (7.3 ± 1.0 m/s) children, even after controlling for risk factors. However, crPWV was markedly elevated (P = 0.002) in overweight-obese American Indian children (7.7 ± 1.1 m/s) compared with white American children (6.8 ± 0.5 m/s), and these differences remained after controlling for blood pressure and more severe obesity in the American Indians. An obesity-matched subgroup analysis indicated that crPWV (7.7 ± 1.1 vs 6.8 ± 0.4 m/s) remained significantly greater in the American Indians (P = 0.03). There were no between-group differences in aortic AIx. These findings indicate an adverse influence of American Indian ethnicity on arterial stiffening in children with elevated adiposity. Arterial stiffness in American Indian children may accelerate early adulthood vascular disease.

[Flow mediated vasodilation in overweight children]

INTRODUCTION

Present knowledge suggests that cardiovascular disease originates and progresses from childhood and adolescence. Endothelial dysfunction is an early and crucial event in atherosclerosis.

PATIENTS AND METHOD

Prospective study that compares Flow Mediated Vasodilation (FMV) in children with overweight (OWC) and normal weight children. An ultrasound transducer a standard method were used to measure FMD.

RESULTS

The study included 82 children, of whom 49 were cases (OWC) and 33 controls. FMV values ranged from -6 to 56% (x=11.1%) in OW, and from 0 to 29.6% (x=16.6%) in control children (P<.005). Paradoxical vasoconstriction was found in 34.7% in OWC as compared to nil in controls (P<.005). A significant association was found between vasoconstriction and central obesity and hypertension.

CONCLUSION

The results of this study show that FMV is lower in obese compared to normal children; thus they are more likely to have endothelial dysfunction.

High lipoprotein(a) concentrations are associated with impaired endothelial function in children

OBJECTIVE

To examine the association between familial high lipoprotein(a), or Lp(a), concentrations and endothelial function in children participating in the Special Turku Coronary Risk Factor Intervention Project study.

STUDY DESIGN

Seven-month-old children (n = 1062) with their families were randomized to a risk intervention group or to a control group. The intervention group received individualized dietary counseling to reduce the total cholesterol concentration. Children's Lp(a) and lipid values were measured repeatedly. At age 11 years, children were recruited to an ultrasound study of the flow-mediated dilation (FMD) of the brachial artery. The association between relative peak FMD and Lp(a) concentration was examined in 198 control and 193 intervention group children by linear regression analyses adjusted for sex, total cholesterol concentration, and basal artery diameter. The analyses were made in both the control and intervention groups and in the familial risk children who had a parent with Lp(a) concentration greater than 250 mg/l.

RESULTS

Lp(a) concentrations were similar at age 11 years in the intervention and control groups. In all control children, FMD (%) associated inversely with Lp(a) concentration: (β [%/1000 mg/L] = -3.74, 95% CI [-6.43, -1.45]; P = .007) and in 68 familial risk children (β = -4.92, 95% CI [-8.18, -1.66]; P = .0037). In the intervention group the associations were lacking (P > .5), and FMD in the children with high Lp(a) concentrations (>500 mg/L, n = 12) had no attenuation (P = .027).

CONCLUSIONS

Familial high Lp(a) concentration is associated with attenuated endothelial function. This association may be mitigated by an early lifestyle intervention.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT00223600.

Cardiovascular magnetic resonance imaging-based computational fluid dynamics/fluid-structure interaction pilot study to detect early vascular changes in pediatric patients with type 1 diabetes

We hypothesized that pediatric patients with type 1 diabetes have cardiac magnetic resonance (CMR) detectable differences in thoracic aortic wall properties and hemodynamics leading to significant local differences in indices of wall shear stress, when compared with age-matched control subjects without diabetes. Pediatric patients with type 1 diabetes were recruited from Children's Hospital of Wisconsin and compared with controls. All underwent morning CMR scanning, 4-limb blood pressure, brachial artery reactivity testing, and venipuncture. Patient-specific computational fluid dynamics modeling with fluid-structure interaction, based on CMR data, determined regional time-averaged wall shear stress (TAWSS) and oscillatory shear index (OSI). Twenty type 1 diabetic subjects, median age 15.8 years (11.6-18.4) and 8 controls 15.4 years (10.3-18.2) were similar except for higher glucose, hemoglobin A1c, and triglycerides for type 1 diabetic subjects. Lower flow-mediated dilation was seen for those with type 1 diabetes (6.5) versus controls (7.8), p = 0.036. For type 1 diabetic subjects, the aorta had more regions with high TAWSS when compared to controls. OSI maps appeared similar. Flow-mediated dilation positively correlated with age at diabetes diagnosis (r = 0.468, p = 0.038) and hemoglobin A1c (r = 0.472, p = 0.036), but did not correlate with aortic distensibility, TAWSS, or OSI. TAWSS did not correlate with any clinical parameter for either group. CMR shows regional differences in aortic wall properties for young diabetic patients. Some local differences in wall shear stress indices were also observed, but a longitudinal study is now warranted.

Non-invasive vascular imaging is associated with cardiovascular risk factors among adolescents with bipolar disorder

Cardiovascular disease (CVD) is exceedingly prevalent among adults with bipolar disorder (BD), implicating BD adolescents as a high-risk group for CVD. Non-invasive ultrasound measures of vascular structure (via carotid intima media thickness [cIMT]) and function (via flow-mediated dilation [FMD]) predict future CVD, and are associated with traditional CVD risk factors among adolescents without mood disorders. This study examined, for the first time, the association of cIMT and FMD with CVD risk factors among adolescents with BD. The presence of multiple potential confounds among adolescents with BD, including various medications and mood states, informs the need to demonstrate whether cIMT and FMD are associated with CVD risk factors in this population specifically. Participants were 30 adolescents, 13-19 years old, with BD, without CVD. High-resolution ultrasonography was used to evaluate vascular structure (cIMT) and function (FMD). Analyses examined associations of cIMT and FMD with traditional CVD risk factors. cIMT was significantly positively associated with systolic blood pressure and waist circumference. FMD was significantly negatively associated with waist circumference, body mass index, triglycerides, and glucose, and positively associated with high-density lipoprotein. cIMT and FMD are associated with traditional CVD risk factors among adolescents with BD. Irrespective of numerous potential confounds, non-invasive vascular ultrasound approaches may be used as CVD risk proxies among adolescents with BD as they are for other adolescents.

Secondhand smoke exposure and endothelial stress in children and adolescents

OBJECTIVE

Links between secondhand smoke exposure and cardiovascular disease in adults are well established. Little is known about the impact of this exposure on cardiovascular status during childhood. The purpose of this study was to investigate relationships between secondhand smoke exposure in children and adolescents and cardiovascular disease risk--systemic inflammation, endothelial stress, and endothelial repair.

METHODS

A total of 145 subjects, aged 9 to 18 years, were studied. Tobacco smoke exposure was determined by hair nicotine level. Cardiovascular risk was assessed by markers of systemic inflammation (C-reactive protein [CRP] and adiponectin); by soluble intercellular adhesion molecule 1 (s-ICAM1), which measures endothelial activation after surface vascular injury; and by endothelial repair. This was measured by prevalence of endothelial progenitor cells (EPCs), which are bone marrow-derived cells that home preferentially to sites of vascular damage.

RESULTS

Hair nicotine was directly correlated with s-ICAM1 (r = 0.4090, P < .0001) and negatively correlated with EPC prevalence (r = -0.2002, P = .0195). There was no relationship between hair nicotine and CRP, and a trend toward a weak relationship with adiponectin. Hair nicotine and body mass index were independent variables in a multivariate model predicting s-ICAM1; hair nicotine was the only significant variable in a model predicting EPC prevalence.

CONCLUSIONS

Secondhand smoke exposure during childhood and adolescence is detrimental to vascular health because s-ICAM1 is a marker for endothelial activation and stress after vascular surface injury, and EPCs contribute to vascular repair. The fact that body mass index is also a factor in the model predicting s-ICAM1 is concerning, in that 2 risk factors may both contribute to endothelial stress.

Subclinical vascular endothelial dysfunctions and myocardial changes with type 1 diabetes mellitus in children and adolescents

Vascular endothelial dysfunction, accelerated thickening of arterial intima, and changes in ventricular functions contribute to increased cardiovascular morbidity in type 1 diabetes mellitus (T1DM). This study aimed to investigate the functional-structural changes in the arteries and myocardium together with affection of highly sensitive C-reactive protein (hsCRP), circulating endothelial cells (CECs), and vitamin C levels in children with T1DM. Also, to test the association with early atherosclerotic changes. The study included 30 children with a diagnosis of T1DM and 30 healthy subjects matched by sex, age, and body mass index. Serum lipids, HbA1c, hsCRP, vitamin C, and CECs were detected. Corrected QT interval (QTc), cardiac dimensions, and left ventricular (LV) functions were assessed using conventional echocardiography. Noninvasive ultrasound was used to measure brachial artery flow-mediated dilation (FMD) responses and carotid intima-media thickness (IMT). The QTc interval was significantly higher in the diabetic patients than in the control subjects (P < 0.001). The findings showed LV diastolic dysfunction as reflected by significantly lower early peak flow velocity, decreased E/A ratio, increased early filling deceleration time (DcT), and prolonged isovolumic relaxation time (IVRT) (P < 0.001 for each). The children with diabetes had a significantly lower FMD response, increased IMT, lower vitamin C level, higher hsCRP, and higher CEC compared with the control subjects (P < 0.001 for each). A positive correlation between CEC and HbA1c was found (P = 0.004). An alteration in myocardial function and endothelial dysfunction may begin early with the association of early atherosclerotic changes. These changes are accelerated when glycemic control is poor. The authors recommend early and close observation of children with diabetes for any alterations in cardiac and vascular endothelial function. Vitamin C supplementation may reduce the risk of complications.

A single consumption of curry improved postprandial endothelial function in healthy male subjects: a randomized, controlled crossover trial

Background

Curry, one of the most popular foods in Japan, contains spices that are rich in potentially antioxidative compounds, such as curcumin and eugenol. Oxidative stress is thought to impair endothelial function associated with atherosclerosis, a leading cause of cardiovascular events. The aim of this study was to determine whether a single consumption of curry meal would improve endothelial function in healthy men.

Methods

Fourteen healthy male subjects (BMI 23.7 ± 2.7 kg/m²; age 45 ± 9 years) were given a single serving of curry meal or spice-free control meal (180 g of curry or control and 200 g of cooked rice; approximately 500 kcal in total) in a randomized, controlled crossover design. Before and 1 hr after the consumption, fasting and postprandial flow-mediated vasodilation (FMD) responses and other parameters were measured.

Results

The consumption of the control meal decreased FMD from 5.8 ± 2.4% to 5.1 ± 2.3% (P = 0.039). On the other hand, the consumption of the curry meal increased FMD from 5.2 ± 2.5% to 6.6 ± 2.0% (P = 0.001), and the postprandial FMD after the curry meal was higher than that after the control meal (P = 0.002). Presence of spices in the curry did not alter significantly the systemic and forearm hemodynamics, or any biochemical parameters including oxidative stress markers measured.

Conclusions

These findings suggest that the consumption of curry ameliorates postprandial endothelial function in healthy male subjects and may be beneficial for improving cardiovascular health.

Trial registration

UMIN Clinical Trials Registry 000012012.

Cardiovascular disease in childhood: the role of obesity

In recent years, childhood obesity is becoming an epidemic health problem. It is now evident from many studies that childhood obesity is correlated with adult excess weight status and the development of risk factors for cardiovascular diseases in adulthood, including hypertension, type 2 diabetes mellitus, dyslipidemia, and metabolic syndrome. The exposure to obesity and to the above risk factors during childhood subsequently lead to atherosclerotic development, such as altered vascular structure and function, although the mechanisms are still unclear. Several non-invasive, and thus easy-to-obtain measures of arterial structure and function, have been shown to be clinically useful in providing information about vasculature early in the course of atherosclerosis, including measurement of endothelial function, carotid intima media thickness, and arterial stiffness. The early detection of cardiovascular abnormalities is essential because the control of the atherogenic process is more effective during its early stages. The present review focuses on the cardiovascular consequences of obesity, on the mechanisms and the methods of measurement of endothelial dysfunction in obese children and adolescents, and on the ways of intervention for the improvement of vascular health.

Time-related arterial changes after allogeneic hematopoietic stem cell transplantation in children

BACKGROUND

Metabolic syndrome is a frequent late effect in young adults after hematopoietic stem cell transplantation (HSCT) performed in childhood.

METHODS

To further study the signs of cardiovascular changes in HSCT patients, we performed noninvasive vascular ultrasonic measurements of arterial stiffness and endothelial function in 25 children (median age: 11.2 y) and in 22 healthy matched controls.

RESULTS

The distensibility of the common carotid artery (CCA) was significantly lower in the patients than in the controls (mean = 0.48, SD = 0.19 vs. mean = 0.64 mm Hg(-1) × 10(-2), SD = 0.28; P = 0.024). The distensibility decreased with time passed after HSCT (P = 0.009). The compliance of the CCA was decreased (mean = 0.10, SD = 0.04 vs. mean = 0.13 mm(2) × mm Hg(-1), SD = 0.05; P = 0.041), and the incremental elastic modulus (E inc) was higher in the patients than in the controls (mean = 2.05, SD = 0.7 vs. mean = 1.6 mm × 10(3), SD = 0.6; P = 0.019). E inc was associated with time passed after HSCT (P = 0.036). The size of the brachial artery and flow-mediated dilation did not differ between the groups.

CONCLUSION

Early mechanical changes of the arterial wall were found at young age after HSCT. Ultrasonography may offer a noninvasive method to find early alterations of the vascular bed and to optimize prevention of atherosclerosis in HSCT patients.

Assessment of endothelial dysfunction in childhood obesity and clinical use

The association of obesity with noncommunicable diseases, such as cardiovascular complications and diabetes, is considered a major threat to the management of health care worldwide. Epidemiological findings show that childhood obesity is rapidly rising in Western society, as well as in developing countries. This pandemic is not without consequences and can affect the risk of future cardiovascular disease in these children. Childhood obesity is associated with endothelial dysfunction, the first yet still reversible step towards atherosclerosis. Advanced research techniques have added further insight on how childhood obesity and associated comorbidities lead to endothelial dysfunction. Techniques used to measure endothelial function were further brought to perfection, and novel biomarkers, including endothelial progenitor cells, were discovered. The aim of this paper is to provide a critical overview on both in vivo as well as in vitro markers for endothelial integrity. Additionally, an in-depth description of the mechanisms that disrupt the delicate balance between endothelial damage and repair will be given. Finally, the effects of lifestyle interventions and pharmacotherapy on endothelial dysfunction will be reviewed.

Evolution of the Arterial Structure and Function From Infancy to Adolescence Is related to Anthropometric and Blood Pressure Changes

Objective—

To develop a normative data set and to study the relationship among arterial structure, different anthropometric measures, blood pressure, and arterial function during healthy childhood using very-high-resolution ultrasound (25–55 MHz).

Methods and Results—

In 135 healthy children between 0 and 18 years of age, we assessed the structure of the carotid arteries, larger peripheral arteries, aorta, and left ventricle with ultrasound. Arterial stiffness was assessed by pulse wave velocity and endothelial function by brachial flow-mediated dilation. Reference curves adjusted for age and body surface area of arterial lumen diameters, intima-media thickness, and adventitia thickness were developed. Arterial walls thicken during childhood predominantly as a result of a progressive increase in intima-media thickness. There were significant associations among lumen diameter ( R 2 range, 0.20–0.88 for different arteries; P <0.001), intima-media thickness ( R 2 range, 0.47–0.85; P <0.001), left ventricular mass ( R 2 =0.90; P <0.001), and adventitia thickness ( R 2 range, 0.15–0.22; P <0.001) with sex, age, body surface, and systolic blood pressure. Arterial wall stress was associated with lumen diameter ( R 2 range, 0.52–0.83; P <0.001) and intima-media thickness ( R 2 range, 0.53–0.88; P <0.001). Limited relationships were found among arterial wall layer thickness, stiffness, and endothelial function.

Conclusion—

In healthy children, the evolution of the arterial structure is mainly related to anthropometrics and blood pressure.

Cardiovascular Risk in Children and Adolescents with Type 1 and Type 2 Diabetes Mellitus

Rising rates of both type 1 and type 2 diabetes mellitus in children have led to increased concern regarding cardiovascular disease (CVD) risk during childhood. Diabetic children face prolonged exposure to hyperglycemia, and have increased risk of both microvascular and macrovascular disease. These circumstances may result in a generation of young adults presenting with cardiovascular outcomes, a tremendous personal and public health toll. In this article, we review CVD risk in type 1 and type 2 diabetes, discuss aspects of pathophysiology, and review current methods of CVD risk assessment. We also identify crucial areas in need of future research in order to devise effective prevention and treatment of CVD risk in children.

Adolescents with congenital adrenal hyperplasia because of 21-hydroxylase deficiency have vascular dysfunction

CONTEXT

Patients with congenital adrenal hyperplasia (CAH) because of 21-hydroxylase deficiency have multiple vascular risk factors. Young adults with CAH have increased intima media thickness, but there have been no studies of vascular function and structure in children with CAH.

OBJECTIVE

To establish whether children with CAH have reduced vascular function and increased carotid intima media thickness (cIMT) when compared to healthy and obese children.

DESIGN AND PATIENTS

Cross-sectional study of 14 patients (14.8 years ± 3.2, seven boys) with CAH secondary to 21-hydroxylase deficiency compared to 28 obese and 53 healthy controls.

MEASUREMENTS

All subjects had assessment of endothelial function flow-mediated dilatation, (FMD), smooth muscle function glyceryl tri-nitrate dilatation (GTN) and cIMT. Anthropometric data, resting blood pressure and biochemical variables were also measured.

RESULTS

Congenital adrenal hyperplasia subjects had significantly reduced FMD (4.5 ± 3.0% vs 7.5 ± 5.2%; P = 0.04) and GTN (17.2 ± 1.6% vs 28.4 ± 8.4%; P < 0.001) when compared to controls and the impairment was comparable to the obese cohort. There was no significant difference in cIMT between groups. CAH subjects had increased homoeostasis model of assessment-insulin resistance [HOMA-IR 2.5 (0.2-2.9) vs 1.8 (0.5-4.2); P = 0.04], waist-to-height ratio (0.47 ± 0.05 vs 0.44 ± 0.04; P = 0.02) and higher systolic blood pressure Z score (0.29 ± 0.9 vs-0.24 ± 0.64, P = 0.01) compared to healthy controls but not when compared to obese controls.

CONCLUSIONS

Subjects with CAH have evidence of vascular dysfunction by adolescence.

Assessment of vascular remodeling after the Fontan procedure using a novel very high resolution ultrasound method: arterial wall thinning and venous thickening in late follow-up

The Fontan circulation is associated with an increased central venous pressure, decreased ventricular preload, and increased afterload. We postulated that these central hemodynamic abnormalities would have consequences for the structural and functional properties of the peripheral arteries and veins, and performed a cross-sectional study in a tertiary health-care setting. We prospectively examined venous and arterial wall morphology by very high resolution ultrasound (VHRU, 25-55 MHz), and function by conventional vascular ultrasound (flow-mediated dilatation, FMD) and applanation tonometry (pulse wave velocity, PWV) in 28 patients after the Fontan procedure (age 14.8 ± 1.3 years) and 54 age-matched controls. Pig venous samples were studied with VHRU and compared with histology for accuracy. The precision of the venous VHRU method was studied in healthy volunteers. The lumen dimension was reduced in Fontans compared with controls in the common carotid, brachial, radial, and femoral arteries (p < 0.05). The common carotid, brachial, radial, ulnar, femoral, and dorsal tibial artery intima-media thicknesses (IMTs) and the brachial, ulnar, and femoral artery adventitial thicknesses were decreased (p < 0.05 for all), while the cubital and dorsal tibial vein IMTs were increased in Fontans (p < 0.001). FMD, abdominal aortic stiffness, and carotid-femoral PWV were similar, while carotid-radial artery PWV was increased in Fontans (p < 0.01). Venous wall layer assessment with VHRU was accurate and precise. The Fontan circulation is associated with significant arterial and venous remodeling, presumably reflecting abnormalities of central hemodynamics. These novel data may be of clinical importance in the circulatory management as well as the understanding of the early pathogenesis of vasculopathy in patients after the Fontan procedure.

Endothelial function in pre-pubertal children at risk of developing cardiomyopathy: a new frontier

Although it is known that obesity, diabetes, and Kawasaki's disease play important roles in systemic inflammation and in the development of both endothelial dysfunction and cardiomyopathy, there is a lack of data regarding the endothelial function of pre-pubertal children suffering from cardiomyopathy. In this study, we performed a systematic review of the literature on pre-pubertal children at risk of developing cardiomyopathy to assess the endothelial function of pre-pubertal children at risk of developing cardiomyopathy. We searched the published literature indexed in PubMed, Bireme and SciELO using the keywords 'endothelial', 'children', 'pediatric' and 'infant' and then compiled a systematic review. The end points were age, the pubertal stage, sex differences, the method used for the endothelial evaluation and the endothelial values themselves. No studies on children with cardiomyopathy were found. Only 11 papers were selected for our complete analysis, where these included reports on the flow-mediated percentage dilatation, the values of which were 9.80±1.80, 5.90±1.29, 4.50±0.70, and 7.10±1.27 for healthy, obese, diabetic and pre-pubertal children with Kawasaki's disease, respectively. There was no significant difference in the dilatation, independent of the endothelium, either among the groups or between the genders for both of the measurements in children; similar results have been found in adolescents and adults. The endothelial function in cardiomyopathic children remains unclear because of the lack of data; nevertheless, the known dysfunctions in children with obesity, type 1 diabetes and Kawasaki's disease may influence the severity of the cardiovascular symptoms, the prognosis, and the mortality rate. The results of this study encourage future research into the consequences of endothelial dysfunction in pre-pubertal children.

Endothelium-independent dilation in children and adolescents

Peak brachial artery dilation post-nitroglycerin (NTG) administration occurs between 3 and 5 min in adults. The purpose of this study was to identify the time to peak dilation response to sublingual NTG (0·3 mg) in youth. Endothelium-independent dilation (EID) was measured in 198 healthy (113 males, 85 females) youth (6-18 years) via ultrasound imaging of the brachial artery following NTG administration. Time to peak EID was 268 s following NTG administration, with no significant (P = 0·6) difference between males and females. There was a significant (P<0·001) difference between EID post-NTG at the 3 versus 4 min, 4 versus 5-min, and 3 versus 5 min time points. Peak EID (males: 24·8 ± 0·5 versus females: 25·3 ± 0·6%, P = 0·6) was not significantly different after accounting for baseline diameter. Peak response to NTG administration occurs between 4 and 5 min. The results demonstrate the importance of measuring EID up to 5-min post-NTG administration in youth.

Impaired endothelial function in preadolescent children with type 1 diabetes

OBJECTIVE

We evaluated the prevalence of endothelial dysfunction as measured by flow-mediated dilatation (FMD) of the brachial artery and carotid intima-media thickness (c-IMT) in relationship to vascular inflammatory biomarkers in preadolescent children with type 1 diabetes.

RESEARCH DESIGN AND METHODS

We studied 21 type 1 diabetic children (aged 8.3 ± 0.3 years with diabetes duration of 4.3 ± 0.4 years) and 15 group-matched healthy siblings (aged 7.6 ± 0.3 years). Fasting plasma glucose (FPG), lipid profile, HbA(1c), high-sensitivity C-reactive protein (hs-CRP), fibrinogen, homocysteine, and erythrocyte (red blood cell [RBC]) folate were evaluated in all subjects. Each subject underwent c-IMT and brachial artery FMD percentage (FMD%) measurements using high-resolution vascular ultrasound.

RESULTS

Type 1 diabetic children had higher FPG (173.4 ± 7.9 mg/dL vs. 81.40 ± 1.7 mg/dL; P < 0.0001), HbA(1c) (8.0 ± 0.2% vs. 5.0 ± 0.1%; P < 0.0001), and hs-CRP (1.8 ± 0.3 vs. 0.70 ± 0.2; P = 0.017) than control children without significant differences in BMI, homocysteine, and fibrinogen levels; RBC folate content; and c-IMT between the groups. Children with type 1 diabetes had lower FMD% than control children (7.1 ± 0.8% vs. 9.8 ± 1.1%; P = 0.04), whereas c-IMT did not differ between groups.

CONCLUSIONS

Preadolescent children with type 1 diabetes and mean diabetes duration of 4 years displayed evidence of low-intensity vascular inflammation and attenuated FMD measurements. These data suggest that endothelial dysfunction and systemic inflammation, known harbingers of future cardiovascular risk, are present even in preadolescent children.

Arterial intima-media thickness, endothelial function, and apolipoproteins in adolescents frequently exposed to tobacco smoke

BACKGROUND

Exposure to tobacco smoke is associated with markers of preclinical atherosclerosis in adults, but its effect on arterial structure in adolescents is unknown.

METHODS AND RESULTS

Healthy 13-year-old adolescents from the atherosclerosis prevention trial STRIP were studied. Maximum carotid and aortic intima-media thickness and brachial artery flow-mediated dilation were measured in 494 adolescents using high-resolution ultrasound. Serum lipid, lipoprotein, and apolipoprotein (Apo) A-I and B concentrations were determined using standard methods. Exposure to tobacco smoke was measured annually between ages 8 and 13 years using serum cotinine concentrations, analyzed with gas chromatography. To define longitudinal exposure, cotinine values of children having serum cotinine measured 2 to 6 times during follow-up were averaged and divided into tertiles (exposure groups): low (n=160), intermediate (n=171), and high (n=163). Adolescents with higher longitudinal exposure to tobacco smoke had increased carotid intima-media thickness (exposure groups [mean+/-SD]: low, 0.502+/-0.079 mm; intermediate, 0.525+/-0.070 mm; high, 0.535+/-0.066 mm; P<0.001) and increased aortic intima-media thickness (exposure groups: low, 0.527+/-0.113 mm; intermediate, 0.563+/-0.139 mm; high, 0.567+/-0.126 mm; P=0.008). The flow-mediated dilation decreased when cotinine level increased (exposure groups: low, 10.43+/-4.34%; intermediate, 9.78+/-4.38%; high, 8.82+/-4.14%; P=0.004). Moreover, ApoB (P=0.014) and ApoB/ApoA-I ratio (P=0.045) increased with increase in cotinine level. The associations between tobacco smoke exposure and ultrasound variables were unchanged after adjusting for traditional atherosclerosis risk factors and for ApoB.

CONCLUSIONS

Frequent exposure to tobacco smoke is independently associated with arterial changes of preclinical atherosclerosis and increased ApoB levels among healthy adolescents. Clinical Trial Registration- clinicaltrials.gov. Identifier: NCT00223600.

Vascular health in children and adolescents: effects of obesity and diabetes

The foundations for cardiovascular disease in adults are laid in childhood and accelerated by the presence of comorbid conditions, such as obesity, diabetes, hypertension, and dyslipidemia. Early detection of vascular dysfunction is an important clinical objective to identify those at risk for subsequent cardiovascular morbidity and events, and to initiate behavioral and medical interventions to reduce risk. Typically, cardiovascular screening is recommended for young adults, especially in people with a family history of cardiovascular conditions. Children and adolescents were once considered to be at low risk, but with the growing health concerns related to sedentary lifestyle, poor diet and obesity, cardiovascular screening may be needed earlier so that interventions to improve cardiovascular health can be initiated. This review describes comorbid conditions that increase cardiovascular risk in youth, namely obesity and diabetes, and describes noninvasive methods to objectively detect vascular disease and quantify vascular function and structure through measurements of endothelial function, arterial compliance, and intima-media thickness. Additionally, current strategies directed toward prevention of vascular disease in these populations, including exercise, dietary interventions and pharmacological therapy are described.

Noninvasive assessment of subclinical atherosclerosis in children and adolescents: recommendations for standard assessment for clinical research: a scientific statement from the American Heart Association

Deterioration in endothelial function and arterial stiffness are early events in the development of cardiovascular diseases. In adults, noninvasive measures of atherosclerosis have become established as valid and reliable tools for refining cardiovascular risk to target individuals who need early intervention. With limited pediatric data, the use of these techniques in children and adolescents largely has been reserved for research purposes. Therefore, this scientific statement was written to (1) review the current literature on the noninvasive assessment of atherosclerosis in children and adolescents, (2) make recommendations for the standardization of these tools for research, and (3) stimulate further research with a goal of developing valid and reliable techniques with normative data for noninvasive clinical evaluation of atherosclerosis in pediatric patients. Precise and reliable noninvasive tests for atherosclerosis in youth will improve our ability to estimate future risk for heart attack and stroke. Currently, large longitudinal studies of cardiovascular risk factors in youth, such as the Bogalusa and Muscatine studies, lack sufficient adult subjects experiencing hard outcomes, such as heart attack and stroke, to produce meaningful risk scores like those developed from Framingham data.

The use of surrogate vascular markers in youth at risk for premature cardiovascular disease

Premature cardiovascular disease (CVD) begins in youth--a crucial period when modification of the disease may have the greatest impact. Failure to diagnose preclinical CVD at this stage misses a major opportunity to prevent the long-term consequences of this disease. An array of surrogate vascular markers (SVMs) are now available that can determine the extent of preclinical vascular injury in the pediatric population. These SVMs include flow-mediated vasodilatation, carotid intima media thickness, arterial stiffness, and biomarkers including high sensitivity C-reactive protein, cell adhesion molecules and methylarginines. We believe that the use of these SVMs will help to develop a better understanding of early pathological vascular changes in youth, facilitate earlier diagnosis of preclinical atherosclerosis and provide an objective measure of the vascular effects of any therapeutic intervention aimed at risk factor modification. Ultimately, our future health will depend on carefully balancing the benefits of early diagnosis and treatment in high-risk youth with the long-term risk of CVD. The application of SVMs in the pediatric population will help us achieve this balance.

Abnormal vascular reactivity at rest and exercise in obese boys

BACKGROUND

Obese children exhibit vascular disorders at rest depending on their pubertal status, degree of obesity, and level of insulin resistance. However, data regarding their vascular function during exercise remain scarce. The aims of the present study were to evaluate vascular morphology and function at rest, and lower limb blood flow during exercise, in prepubertal boys with mild-to-moderate obesity and in lean controls.

MATERIALS AND METHODS

Twelve moderately obese prepubertal boys [Body Mass Index (BMI: 23.9+/-2.6 kg m(-2))] and thirteen controls (BMI:17.4+/-1.8 kg m(-2)), matched for age (mean age: 11.6+/-0.6 years) were recruited. We measured carotid intima-media thickness (IMT) and wall compliance and incremental elastic modulus, resting brachial flow-mediated dilation (FMD) and nitrate-dependent dilation (NDD), lower limb blood flow during local knee-extensor incremental and maximal exercise, body fat content (DEXA), blood pressure, blood lipids, insulin and glucose.

RESULTS

Compared to lean controls, obese boys had greater IMT (0.47+/-0.06 vs. 0.42+/-0.03 mm, P<0.05) but lower FMD (4.6+/-2.8 vs. 8.8+/-3.2%, P<0.01) in spite of similar maximal shear rate, without NDD differences. Lower limb blood flow (mL min(-1).100 g(-1)) increased significantly from rest to maximal exercise in both groups, although obese children reached lower values than lean counterparts whatever the exercise intensity.

CONCLUSIONS

Mild-to-moderate obesity in prepubertal boys without insulin resistance is associated with impaired endothelial function and blunted muscle perfusion response to local dynamic exercise without alteration of vascular smooth muscle reactivity.