Vascular Health and Risk Factors in Children With Down Syndrome

Study Overview
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Brief Summary
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This is a prospective, multicenter, cross-sectional study to evaluate prevalence of vascular risk factors in children with Down Syndrome and to determine the association between vascular disease risk factors and objective markers of early atherosclerosis.

Official Title
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Vascular Health and Risk Factors in Children With Down Syndrome

Conditions
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Down Syndrome, Cardiovascular Risk Factor, Atherosclerosis

Intervention / Treatment
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* Other: Evaluate vascular disease risk factors in children with Down Syndrome
* Other: Determine the associations between cardiovascular disease risk factors and markers of early atherosclerosis in children with Down Syndrome


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: All children with Down Syndrome (10.0-18.0 years of age) Children with translocations and mosaicism Children with and without CHD Exclusion Criteria: Patients with a history of hypoplastic arch, coarctation or catheter or surgical based aorta interventions Patients who are currently treated or have been treated with chemotherapy for cancer or a myeloproliferative disorder within 1 year of the study Participants whose parent/legally authorized representative (LAR) perceives the child is not able to cooperate with vascular imaging studies

Ages Eligible for Study
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Minimum Age: 10 Years
Maximum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Children ages 10.0 to 18.0<br> | Other: Evaluate vascular disease risk factors in children with Down Syndrome<br>* We will determine CV disease risk profiles in children with DS at our centers. We will compare these data to published national norms of children without DS. Risk factor data will include: anthropometric measures; blood pressure; history of congenital heart disease and associated surgery, sleep apnea, hypothyroidism, and cancer; fasting blood draw [lipid panel with subfractions (NMR), insulin, glucose, and CRP].<br>Other: Determine the associations between cardiovascular disease risk factors and markers of early atherosclerosis in children with Down Syndrome<br>* We will perform PWV, CIMT, and CD studies in children with DS and compare these data to available data in children without DS. We will also perform multivariable analysis of the influence of combinations of CV disease risk factors on markers of early atherosclerosis in children with DS. Hypothesis: CV disease risk factors will correlate with markers of early atherosclerosis in children with DS but the associations between risk factors and markers of early atherosclerosis will differ between children with DS vs. the general population of children.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| The difference in mean pulse wave velocity between children with Down syndrome and published national data in children without Down syndrome at one time point. | Pulse wave velocity (PWV) is a non-invasive imaging measure of arterial stiffness. Pulse wave velocity measures vascular stiffness by evaluating the time for a pressure wave to travel through the aorta. The velocity is determined by the elasticity and geometry of the vessel. PWV will be measured using a SphygmoCor device. With the participant in the supine position and ECG leads attached, the maximal pulsation of the right carotid and right femoral artery will be marked and measured from the suprasternal notch using a tape measure (carotid) and caliper (femoral). A tonometer will record the carotid and femoral impulses. The device calculates PWV as the difference in the carotid-to-distal path length divided by the difference in R-wave-to-waveform times (∆distance/∆time, m/sec). Measurements will be in triplicate and averaged. PWV can be completed in  30 mins. | One day patient visit | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| The difference in mean carotid intimal medial thickness between children with Down syndrome and published national data in children without Down syndrome measured at 1 time point. | Carotid intimal medial thickness (CIMT) is a non-invasive imaging measure of carotid artery thickness. B-mode ultrasound with a high-resolution linear array vascular transducer will be used to record common, bulb, and internal CIMT. | One day patient visit | 
| Correlation of body mass index (BMI) anthropometric cardiovascular risk factors on PWV and CIMT in children with Down syndrome. | Height (centimeters) will be measured using standard stadiometers and weight (kilograms) using a calibrated scale available at each site. BMI (kg/m2) will be calculated and converted to age- and sex-matched Down Syndrome percentiles. Measured at 1 time point. | One day patient visit | 
| Correlation of waist circumference anthropometric cardiovascular risk factors on PWV and CIMT in children with Down syndrome. | Waist circumference will be measured at the top of the posterior iliac crest (NHANES standard) and normalized by calculating waist to height ratio. Measured at 1 time point. | One day patient visit | 
| Correlation of serologic cardiovascular risk factors include fasting lipid panel on PWV and CIMT in children with Down syndrome. | A fasting lipid profile will be obtained to measure total cholesterol, triglycerides, and HDL cholesterol. Trained pediatric phlebotomists will perform the blood draw after the participant has fasted ≥10 hours. A standard lipid profile will provide total cholesterol, HDL cholesterol, and triglycerides. LDL will be calculated using the Friedwald equation when triglycerides are <400 mg/dL. For triglycerides ≥400 mg/dl, LDL will be measured directly via a homogeneous enzymatic assay. Measured at 1 time point. | One day patient visit | 
| Correlation of serologic cardiovascular risk factors include lipoprotein on PWV and CIMT in children with Down syndrome. | Lipoprotein subfractions by NMR will be used to describe lipid particle number and size. These lipoprotein measurements likely estimate CV risk more accurately than a standard lipid profile alone. Lipoprotein sub-fractionation will be completed using proton NMR signals. Measured at 1 time point. | One day patient visit | 
| Correlation of serologic cardiovascular risk factors include insulin resistance on PWV and CIMT in children with Down syndrome. | Insulin resistance will be assessed by fasting serum glucose, hemoglobin A1C, and insulin level since diabetes (fasting glucose ≥126 mg/dL or hemoglobin A1C ≥6.5%) is a major risk factor. Measured at 1 time point. | One day patient visit | 
| Correlation of clinical cardiovascular risk factors on PWV and CIMT in children with Down syndrome. | A detailed personal history for congenital heart disease (CHD) and associated surgery, sleep apnea, hypothyroidism, and cancer will be obtained as all are common in the population with Down Syndrome and increase the risk for cardiovascular disease in adulthood. The fundamental CHD and associated surgery will be obtained from the medical records. The parent/LAR will be questioned and the medical record reviewed for a history of sleep apnea, hypothyroidism, and cancer (yes/no). Measured at 1 time point. | One day patient visit | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Down Syndrome, Cardiovascular Risk Factor, Atherosclerosis