Impaired endothelial function in pediatric patients with Turner syndrome and healthy controls: a case-control study. Int J Pediatr Endocrinol. 2012;2012:5. [PMID: 22472028 PMCID: PMC3388952 DOI: 10.1186/1687-9856-2012-5]

Carotid Intima-Media Thickness and Cardiometabolic Profile in Turner Syndrome: A Cross-Sectional Study

INTRODUCTION

Turner syndrome (TS), one of the most common chromosomal abnormalities in females, often results in adult cardiovascular and metabolic complications. Information on pediatric age is scarce. This study aimed to compare the presence of cardiometabolic risk factors in children with TS and healthy controls.

METHODS

This is a cross-sectional study comparing patients with TS to age-matched healthy controls, regarding cardiometabolic risk factors including lipid profile, fasting glucose, insulin resistance, body composition, body mass index, blood pressure, and carotid intima-media thickness (cIMT).

RESULTS

We included nine TS patients and nine controls with a median age of 13 years (9-14 years). Three TS patients and three controls were prepubertal. All TS patients received growth hormone treatment (GHT), median treatment of six years (3-10 years); four patients underwent treatment with estradiol. No statistically significant differences were detected between TS patients and controls regarding body mass index (BMI), cholesterol levels, and insulin resistance. cIMT indexed to body surface area showed no significant differences between TS patients and controls (0.37 vs 0.35 mm/m2, respectively, p=0.605). TS patients had lower body fat levels (7.2% vs 34.9%, p=0.004). On the other hand, TS patients had higher levels of systolic (z-score 1.04 vs -0.08, p=0.001) and diastolic (z-score 1.08 vs 0.33, p=0.031) blood pressure (BP) and aspartate (AST) and alanine (ALT) aminotransferase levels (26 vs 20 U/L, p=0.008 and 19 vs 14 U/L, p=0.004, respectively).

CONCLUSION

Patients with TS, all submitted to GHT, had lower body fat levels compared with controls, despite similar BMI. Although we found no differences in cIMT between the two groups, young girls with TS had higher BP and transaminase levels. Early anthropometric, cardiovascular, and analytical monitoring of patients with TS is essential to detect abnormalities and prevent further complications.

Abnormal Body Composition Increases the Cardiometabolic Risk in Adolescents and Young Adults With Turner Syndrome

OBJECTIVE

To determine the cardiometabolic risk of adolescents and adults with Turner syndrome (TS) and whether and how anthropometry and body composition predict this risk.

METHODS

We compared the anthropometric, biochemical, and dual-energy x-ray absorptiometry-derived body composition parameters of 103 girls and women with TS aged 12 to 30 years and 103 controls of the same age and body mass index: (1) between TS with and without metabolic syndrome (MetS), (2) between the different karyotypes of TS, and (3) between growth hormone recipients and nonrecipients.

RESULTS

Individuals with TS had higher prevalence rates of truncal obesity (57.2%), MetS (37.9%), prediabetes (20.4%), dyslipidemia (73.8%), hypertension (9.7%), and hepatic steatosis (15.5%) and a greater total body fat percentage (38.43% vs 34.26%) and fat mass index (9.15 vs 6.71 kg/m2) but a lower lean mass index (11.05 vs 12.49 kg/m2) than controls (P <.001). Individuals with TS and MetS (n = 39) had a higher total body fat percentage (41.74% vs 36.42%, P <.0001), truncal fat percentage (44.66% vs 36.09%, P <.0001), and visceral adipose tissue mass (495.57 vs 276 g, P <.0001) than those with TS but without MetS. Those with classic TS (45,X) had a higher prevalence of prediabetes (32.6% vs 10.5%, P =.01). Growth hormone recipients had a lower prevalence of MetS and lesser truncal obesity. Altered body composition was significantly correlated with metabolic risk. The truncal fat percentage independently predicted MetS (odds ratio, 1.12; 95% confidence interval, 1.003-1.24; P =.04). Waist circumference and waist-hip ratio predicted metabolic risk with good sensitivity and specificity.

CONCLUSION

Adverse cardiometabolic risk and altered body composition start early in life in TS. Postpubertal women with TS should be routinely assessed for truncal obesity, dysglycemia, dyslipidemia, and liver steatosis, irrespective of body mass index and karyotype.

Components of the metabolic syndrome in girls with Turner syndrome treated with growth hormone in a long term prospective study

Background

Components of the metabolic syndrome are more common in patients with Turner syndrome (TS) than in the general population. Long-term growth hormone (GH) treatment also affects the parameters of carbohydrate metabolism. Therefore, all these factors should be monitored in girls with TS.

Objective

To assess the occurrence of metabolic syndrome components in TS girls before GH treatment and to monitor changes in metabolic parameters throughout GH therapy.

Patients and method

89 TS patients were enrolled in the study. Clinical and laboratory data after the 1st (V1), 3rd (V3), 5th (V5) and 10th (V10) year of GH therapy was available respectively in 60, 76, 50 and 22 patients. The patients' biochemical phenotypes were determined by glucose 0', 120', insulin 0', 120', HOMA-IR, Ins/Glu ratio, HDL-cholesterol and triglycerides (TG) concentration.

Results

Obesity was found during V0 in 7.9% of patients,V1 - 5%, V3 - 3.9%, V5 - 2%, V10 - 0%. No patient met diagnostic criteria for diabetes. A significant increase in the basal plasma glucose 0' was found in the first five years of therapy (pV0-V1 < 0.001; pV0-V3 = 0.006; pV0-V5 < 0.001). V10 glucose 120' values were significantly lower than at the onset of GH treatment (pV0-V10 = 0.046). The serum insulin 0' and 120' concentrations as well as insulin resistance increased during treatment. No statistically significant differences in serum TG and HDL-cholesterol levels during GH therapy were found.

Conclusion

The development of insulin resistance and carbohydrate metabolism impairment have the greatest manifestations during GH therapy in girls with TS. Monitoring the basic parameters of carbohydrate-lipid metabolism in girls with TS seems particularly important.

Vascular Function and Intima-Media Thickness in Children and Adolescents with Growth Hormone Deficiency: Results from a Prospective Case-Control Study

INTRODUCTION

Growth hormone deficiency (GHD) may be associated with subtle cardiovascular abnormalities, reversible upon starting GH treatment. Data on vascular morphology and function in GHD children are scanty and inconclusive. The aim of our study was to evaluate the effects of GHD and GH treatment on endothelial function and intima-media thickness (IMT) in children and adolescents.

METHODS

We enrolled 24 children with GHD (10.85 ± 2.71 years) and 24 age-, sex-, and BMI-matched controls. We evaluated anthropometry, lipid profile, asymmetric dimethylarginine (ADMA), brachial flow-mediated dilatation (FMD), and IMT of common (cIMT) and internal (iIMT) carotid artery at study entry in all subjects and after 12 months of treatment in GHD children.

RESULTS

At baseline GHD, children had higher total cholesterol (163.17 ± 18.66 vs. 149.83 ± 20.68 mg/dL, p = 0.03), LDL cholesterol (91.18 ± 20.41 vs. 77.08 ± 19.73 mg/dL, p = 0.019), atherogenic index (AI) (2.94 ± 0.71 vs. 2.56 ± 0.4, p = 0.028), and ADMA (215.87 ± 109.15 vs. 164.10 ± 49.15 ng/mL, p < 0.001), compared to controls. GHD patients also exhibited increased higher waist-to-height ratio (WHtR) compared to controls (0.48 ± 0.05 vs. 0.45 ± 0.02 cm, p = 0.03). GH therapy resulted in a decrease in WHtR (0.44 ± 0.03 cm, p = 0.001), total (151.60 ± 15.23 mg/dL, p = 0.001) and LDL cholesterol (69.94 ± 14.40 mg/dL, p < 0.0001), AI (2.28 ± 0.35, p = 0.001), and ADMA (148.47 ± 102.43 ng/mL, p < 0.0001). GHD showed lower baseline FMD than controls (8.75 ± 2.44 vs. 11.85 ± 5.98%, p = 0.001), which improved after 1-year GH treatment (10.60 ± 1.69%, p = 0.001). Baseline cIMT and iIMT were comparable between the two groups, but slightly reduced in GHD patients after treatment.

CONCLUSION

GHD children may exhibit endothelial dysfunction in addition to other early atherosclerotic markers like visceral adiposity, and altered lipids, which can be restored by GH treatment.

Endothelial Peripheral Arterial Tonometry (Endo-PAT 2000) use in paediatric patients: a systematic review

OBJECTIVES

Endo Peripheral Artery Tonometry (EndoPAT-2000) is a non-invasive technology for measuring endothelial dysfunction (ED). The reactive hyperaemia index (RHI) is resulted and is low when ED is present. We aim to synthesise the literature on paediatric ED that used Endo-PAT analysis.

DESIGN

A comprehensive systematic review was conducted from January 2015 to March 2021. The databases included Cochrane, MEDLINE EBSCO, EMBASE (Ovid), PUBMED and CINAHL EBSCO. Exclusion criteria were: (1) If a study used a different device, for example, (2) If the study had no results. Inclusion criteria were: (1) Published in the English, (2) more than 50% of study subjects were in the paediatric age range, (3) data relevant to paediatric age range children could be extrapolated from all data, where not all study subjects were children.

RESULTS

Following the removal of duplicates, 156 articles were initially identified. Following exclusion, 50 articles were included for review. We have subdivided these papers into different systems for ease of reference and have reported our findings in six tables: patients with type 1/2 diabetes, obesity, cardiovascular, respiratory, psychiatric conditions and miscellaneous diseases. For each, the study design, population, control group (if available), RHI results and conclusions were reported.

CONCLUSIONS

A number of papers using Endo-PAT for children with various chronic diseases have evidence of ED. However, in many cases, there has only been a single cohort study using Endo-PAT. Further studies are required to validate these findings and to help characterise the cardiovascular risk profile of children with chronic disease. Further studies are also required that will characterise more completely the cardiovascular risk profile of these children.Consensus on other vascular risk markers that could be included in future studies is ideal and if accomplished, this would facilitate meta-analyses of studies of relatively rare conditions.

MicroRNA-126-3p/5p and Aortic Stiffness in Patients with Turner Syndrome

Background: Turner Syndrome (TS) is a relatively rare X-chromosomal disease with increased cardiovascular morbidity and mortality. This study aimed to identify whether the circulating miR-126-3p/5p are involved in the pathophysiology of vascular dysfunction in TS. Methods: Using the RT-qPCR, the abundance levels of miR-126-3p and miR-126-5p were determined in 33 TS patients and 33 age-matched healthy volunteers (HVs). Vascular screening, including the assessment of blood pressure, pulse wave velocity, augmentation index, aortic deformation, arterial distensibility, and arterial elastance, was conducted in TS patients and HVs. Results: The abundance levels of miR-126-3p and miR-126-5p were significantly higher in TS patients compared to HVs (p < 0.0001). Within the TS cohort, miR-126-3p/5p correlated significantly with aortic deformation (r = 0.47, p = 0.01; r = 0.48, p < 0.01) and arterial distensibility (r = 0.55, p < 0.01; r = 0.48, p < 0.01). In addition, a significant negative correlation was demonstrated between miR-126-3p and arterial elastance (r = −0.48, p = 0.01). The receiver operating characteristic analysis showed that miR-126-3p and miR-126-5p separated the tested groups with high sensitivity and specificity. Conclusions: The abundance levels of miR-126-3p and miR-126-5p were significantly higher in TS patients compared to HVs. Within the TS cohort, a lower abundance level of miR-126-3p and miR-126-5p was linked with a significantly higher aortic stiffness.

Effect of Growth Hormone Treatment on the Concentration of Selected Metabolic Markers in Girls With Turner Syndrome

Background

As Turner syndrome (TS) predisposes to obesity and metabolic disorders, and their complications, such as cardiovascular diseases, are the main causes of shortened life expectancy in patients with TS, new metabolic markers that could serve as early predictors of dysmetabolic state are sought.

Objective

Assessment of MMP-1 (matrix metalloproteinase-1), MMP-2 (matrix metalloproteinase-2), MMP-9 (matrix metallopeptidase-9), BDNF (brain-derived neurotrophic factor), GDNF (glial cell line-derived neurotrophic factor), and VEGF (vascular endothelial growth factor) before the onset of growth hormone (GH) therapy and then during GH treatment as well as markers assessment during GH medication in girls with TS to establish marker stability and repeatability, and the impact of GH on markers concentration.

Method

The concentrations of circulating MMP-1, MMP-2, MMP-9, BDNF, GDNF, and VEGF were measured in nine girls with TS before the onset of GH therapy and then after at least 3 months of treatment period. Subsequently, markers concentration was determined in 17 girls during GH medication, with the first determination after at least a 3-month treatment period. The patients' clinical and biochemical phenotypes were determined by weight, height, BMI, total cholesterol, HDL cholesterol, triglycerides, and glucose concentration.

Results

Comparison of markers concentration revealed a significantly higher concentration of MMP-2 in patients undergoing GH treatment (132.1 ± 42.05) than before the onset of therapy (105.0 ± 45.5, p=0.045). The values of the first measurement of VEGF in girls with TS undergoing GH therapy were significantly higher than those during the second measurement (30.9 ± 33.4 vs. 12.5 ± 11.7, p=0.029). There were no statistically significant differences between the measurements of the remaining markers concentration at any stage of the analysis.

Conclusion

Increase in MMP-2 concentration is visible during GH therapy in comparison to the pre-GH period in girls with TS which demands confirmation in subsequent tests. The role of VEGF requires further studies in the context of carbohydrate-lipid disturbances in girls with TS and its association with GH treatment.

Endothelial impairment evaluation by peripheral arterial tonometry in pediatric endocrinopathies: A narrative review

Endothelial dysfunction (ED) is characterized by an imbalance between vasodilator and vasoconstriction agents. Several pathological conditions clinically diagnosed in childhood and adolescence are characterized by ED and increased risk for early development of microangiopathic and macroangiopathic impairment, in particular type 1 diabetes mellitus (T1DM), T2DM, obesity, metabolic syndromeand pituitary dysfunction associated to various endocrinopathies. More recently insulin resistance following chemotherapy or radiotherapy for tumors, bone marrow transplantation for hematological malignancies (i.e., cancer survivors), or immunosuppressive treatment for solid organ transplantation has been observed. Assessment of ED by means of non-invasive techniques is the gold standard for early ED detection before clinical manifestation. It is aimed to recognize patients at risk and to avoid the development and progression of more serious illnesses. Reactive hyperemia-peripheral artery tonometry is a noninvasive technique to assess peripheral endothelial function by measuring modifications in digital pulse volume during reactive hyperemia, and represents a non-invasive, reproducible and operator-independent tool able to detect precocious ED. This narrative review aimed to provide an overview of the most important papers regarding ED detection by EndoPat 2000 in children and adolescents with different endocrine diseases. A comprehensive search of English language articles was performed in the MEDLINE database without using other search filters except the publication interval between 2005 and 2020.

Cardiovascular Complications in Patients with Turner's Syndrome

Turner's or Turner syndrome (TS) is the most prevalent chromosomal abnormality in live female births. Patients with TS are predisposed to an increased risk of cardiovascular diseases (CVD), mainly due to the frequently observed congenital structural cardiovascular defects, such as valvular and aortic abnormalities (coarctation, dilatation, and dissection). The increased prevalence of cardiometabolic risk factors, such as arterial hypertension, insulin resistance, diabetes mellitus, dyslipidaemia, central obesity, and increased carotid intima-media thickness, also contribute to increased morbidity and mortality in TS patients. Menopausal hormone therapy (MHT) is the treatment of choice, combined with growth hormone (GH). Although MHT may, in general, ameliorate CVD risk factors, its effect on CVD mortality in TS has not yet been established. The exact effect of GH on these parameters has not been clarified. Specific considerations should be provided in TS cases during pregnancy, due to the higher risk of CVD complications, such as aortic dissection. Optimal cardiovascular monitoring, including physical examination, electrocardiogram, CVD risk factor assessment, and transthoracic echocardiography, is recommended. Moreover, the cardiac magnetic resonance from the age of 12 years is recommended due to the high risk of aortic aneurysm and other anatomical vascular complications.

Arterial stiffness in young women with Turner syndrome using cardio-ankle vascular index

PURPOSE

Patients with Turner syndrome (TS) have increased risk of morbidities and mortality related to cardiovascular complications. Cardio-ankle vascular index (CAVI) is a novel method of evaluating arterial stiffness independent of changes in blood pressure. We compared arterial stiffness using CAVI between TS patients and healthy control subjects.

METHODS

Nineteen young women with TS (mean, 26.8 years; range, 20.0-35.1 years) and 23 healthy women matched for age and body mass index (BMI) were recruited for CAVI measurements at Seoul National University Hospital between 2010 and 2013. Anthropometric parameters, fasting blood testing and measurements of CAVI were compared between the 2 groups.

RESULTS

TS patients were significantly shorter (mean: 150.1 cm vs. 160.7 cm, P&lt;0.001) and had lower body weight (mean: 47.0 kg vs. 55.5 kg, P=0.014) than healthy controls, without difference in BMI. CAVI (6.5±0.6 vs. 6.1±0.6, P=0.039) was significantly higher in TS patients compared to healthy controls. Age was positively associated with CAVI (r=0.403, P=0.008) in univariate analysis. After adjusting for age, TS was associated with CAVI (P=0.006).

CONCLUSION

Young women with TS showed increased arterial stiffness measured by CAVI compared to healthy women after adjusting for age, suggesting inherent vasculopathy in TS patients.

In utero programming and early detection of cardiovascular disease in the offspring of mothers with obesity

The offspring of women with obesity during their pregnancy are exposed to an altered intra-uterine environment. A subsequent influence on the cardiovascular development during fetal life is assumed. In the present thematic review, we report on the current knowledge about this early development of cardiovascular disease from fetal life until adolescence. Based on animal studies, different contributing mechanisms have been hypothesized that still need confirmation in human subjects. Insulin resistance, increased levels of leptin, chronic inflammatory state, perturbation of sympathetic tone and epigenetic modifications contribute to a suboptimal nutrient environment and changed hemodynamics. The ensuing aberrant cardiomyocyte development, impaired endothelial cell relaxation and atherogenic lipid profile put these children at risk for the development of endothelial cell dysfunction. Increasing possibilities for early detection of this preliminary stage of atherosclerotic disease offer new insights into future prevention and treatment strategies. Future research should focus on further unraveling the effect of moderate intense, aerobic exercise. Since it is used to treat the condition in children and adolescents with good results, it might be a contributor to tackling endothelial cell dysfunction at its cradle when applied in early pregnancy.

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.

Clinical practice guidelines for the care of girls and women with Turner syndrome: proceedings from the 2016 Cincinnati International Turner Syndrome Meeting

Turner syndrome affects 25-50 per 100,000 females and can involve multiple organs through all stages of life, necessitating multidisciplinary approach to care. Previous guidelines have highlighted this, but numerous important advances have been noted recently. These advances cover all specialty fields involved in the care of girls and women with TS. This paper is based on an international effort that started with exploratory meetings in 2014 in both Europe and the USA, and culminated with a Consensus Meeting held in Cincinnati, Ohio, USA in July 2016. Prior to this meeting, five groups each addressed important areas in TS care: 1) diagnostic and genetic issues, 2) growth and development during childhood and adolescence, 3) congenital and acquired cardiovascular disease, 4) transition and adult care, and 5) other comorbidities and neurocognitive issues. These groups produced proposals for the present guidelines. Additionally, four pertinent questions were submitted for formal GRADE (Grading of Recommendations, Assessment, Development and Evaluation) evaluation with a separate systematic review of the literature. These four questions related to the efficacy and most optimal treatment of short stature, infertility, hypertension, and hormonal replacement therapy. The guidelines project was initiated by the European Society for Endocrinology and the Pediatric Endocrine Society, in collaboration with The European Society for Pediatric Endocrinology, The Endocrine Society, European Society of Human Reproduction and Embryology, The American Heart Association, The Society for Endocrinology, and the European Society of Cardiology. The guideline has been formally endorsed by the European Society for Endocrinology, the Pediatric Endocrine Society, the European Society for Pediatric Endocrinology, the European Society of Human Reproduction and Embryology and the Endocrine Society. Advocacy groups appointed representatives who participated in pre-meeting discussions and in the consensus meeting.

Can Brain Natriuretic Peptides and Osteoprotegerin Serve As Biochemical Markers for the Detection of Aortic Pathology in Children and Adolescents with Turner Syndrome?

Turner syndrome (TS) is a chromosomal disorder that affects 1:2,000 females. It results from either the complete or partial loss of the X chromosome as well as other aberrations. Clinical features of TS include short stature, delayed puberty, and congenital cardiac malformations. TS children also have an increased prevalence of cardiometabolic risk factors, which predisposes them to complications like coronary artery disease, cerebrovascular-related deaths, and aortic dissection. Early cardiac imaging, such as echocardiography and cardiac magnetic resonance imaging, are recommended to detect underlying aortic pathology. However, these modalities are limited by cost, accessibility, and are operator dependent. In view of these shortcomings, alternative methods, like vascular biomarkers, are currently being explored. There are only a few studies that have examined the relationship between B-type natriuretic peptide (BNP), N-terminal pro BNP (NT pro-BNP), and osteoprotegerin (OPG) and aortic disease in TS, and thus the data are only in proof-of-concept stages. Further meticulous longitudinal studies are required before BNP, NT pro-BNP, and OPG are used as vascular biomarkers for the detection of aortic disease in childhood and adolescent TS.

Skeletal muscle microvascular function in girls with Turner syndrome

BACKGROUND

Exercise intolerance is prevalent in individuals with Turner Syndrome (TS). We recently demonstrated that girls with TS have normal aerobic but altered skeletal muscle anaerobic metabolism compared to healthy controls (HC). The purpose of this study was to compare peripheral skeletal muscle microvascular function in girls with TS to HC after exercise. We hypothesized that girls with TS would have similar muscle blood-oxygen level-dependent (BOLD) magnetic resonance imaging (MRI) signal responses during recovery from exercise compared to HC.

METHODS

Thirteen TS participants and 8 HC completed testing. BOLD MRI was used to measure skeletal muscle microvascular response during 60 second recovery, following 60 s of exercise at 65% of maximal workload. Exercise and recovery were repeated four times, and the BOLD signal time course was fit to a four-parameter sigmoid function.

RESULTS

Participants were 13.7 ± 3.1 years old and weighed 47.9 ± 14.6 kg. The mean change in BOLD signal intensity following exercise at the end of recovery, the mean response time of the function/the washout of deoxyhemoglobin, and the mean half-time of recovery were similar between the TS and HC groups.

CONCLUSIONS

Our results demonstrate that compared to HC, peripheral skeletal muscle microvascular function following exercise in girls with TS is not impaired.

GENERAL SIGNIFICANCE

This study supports the idea that the aerobic energy pathway is not impaired in children with TS in response to submaximal exercise. Other mechanisms are likely responsible for exercise intolerance in TS; this needs to be further investigated.

Cardiometabolic and vascular risks in young and adolescent girls with Turner syndrome

BACKGROUND

Turner syndrome (TS) is the most common chromosomal abnormality in females and is associated with several co-morbidities. It commonly results from X monosomy which is diagnosed on a 30 cell karyotype. Congenital heart disease is a clinical feature in 30% of cases. It is becoming evident that TS patients have an increased risk of cardiovascular and cerebrovascular diseases.

SCOPE OF REVIEW

This review provides a detailed overview of the literature surrounding cardiometabolic health in childhood and adolescent TS. In addition, the review also summarises the current data on the impact of growth hormone (GH) therapy on cardiometabolic risk in paediatric TS patients.

MAJOR CONCLUSIONS

Current epidemiological evidence suggests that young women and girls with TS have unfavourable cardiometabolic risk factors which predispose them to adverse cardiac and cerebrovascular outcomes in young adulthood. It remains unclear whether this risk is the result of unidentified factors which are intrinsic to TS, or whether modifiable risk factors (obesity, hypertension, hyperglycaemia) are contributing to this risk.

GENERAL SIGNIFICANCE

From a clinical perspective, this review highlights the importance of regular screening and pro-active management of cardiometabolic risk from childhood in TS cohorts and that future research should aim to address whether modification of these variables at a young age can alter the disease process and atherosclerotic outcomes in adulthood.

Methodological considerations and practical recommendations for the application of peripheral arterial tonometry in children and adolescents

Endothelial dysfunction is recognized as the primum movens in the development of atherosclerosis. Its crucial role in both cardiovascular morbidity and mortality has been confirmed. In the past, research was hampered by the invasive character of endothelial function assessment. The development of non-invasive and feasible techniques to measure endothelial function has facilitated and promoted research in various adult and paediatric subpopulations. To avoid user dependence of flow-mediated dilation (FMD), which evaluates nitric oxide dependent vasodilation in large vessels, a semi-automated, method to assess peripheral microvascular function, called peripheral arterial tonometry (Endo-PAT(®)), was recently introduced. The number of studies using this technique in children and adolescents is rapidly increasing, yet there is no consensus with regard to either measuring protocol or data analysis of peripheral arterial tonometry in children and adolescents. Most paediatric studies simply applied measuring and analysing methodology established in adults, a simplification that may not be appropriate. This paper provides a detailed description of endothelial function assessment using the Endo-PAT for researchers and clinicians. We discuss clinical and methodological considerations and point out the differences between children, adolescents and adults. Finally, the main aim of this paper is to provide recommendations for a standardised application of Endo-PAT in children and adolescents, as well as for population-specific data analysis methodology.

Correlation between endothelial function measured by finger plethysmography in children and HDL-mediated eNOS activation -- a preliminary study

BACKGROUND

The noninvasive measurement of endothelial function is a very powerful tool to assess cardiovascular disease. Especially in children this is not an easy task, and therefore an easy method like the Endo-Pat device is helpful. Due to the still existing uncertainties of the validity of endothelial measurement by the Endo-PAT device in children, we thought to analyze the correlation between endothelial functional measurement by Endo-PAT, and the capability of HDL to modify nitric oxide (NO) production by phosphorylation of endothelial nitric oxide synthase at the stimulatory site (Ser(1177)) and the inhibitory site (Thr(495)).

METHODS

The reactive hyperemic index (RHI) was measured in 11 school children by the Endo-PAT device. HDL was isolated by ultracentrifugation, and the capability to stimulate eNOS phosphorylation was assessed in cell culture.

RESULTS

A close correlation between the RHI and the eNOS-Ser(1177) phosphorylation (r=0.66, p=0.02) and the eNOS-Thr(495) phosphorylation (r=-0.60, p=0.04) was detected.

CONCLUSION

The results obtained in our limited study performed in healthy children supports the validity of endothelial function measurement in children using the Endo-PAT device. Nevertheless, studies measuring FMD and the RHI index need to confirm the strength of the Endo-Pat device also in children.