Down Syndrome (Trisomy 21)VDSNCT07630207
Vascular Function in Adults With Down Syndrome
An observational study of Down Syndrome (Trisomy 21), run by University of Nevada, Las Vegas at 1 site in United States.
Trial summary
Adults with Down syndrome (Ds) are often thought to have a lower risk of heart and blood vessel disease because they tend to have lower blood pressure (BP) and fewer heart attacks than people without Ds. Read more about this study
- Who is it for?
- Ages 18 to 35 yearsHealthy volunteers can take part
- Conditions the study is for
- Down Syndrome (Trisomy 21)
- How many people
- 46 participants
- Where
- 1 siteUnited States
- Study dates
- 9 Apr 2026to 31 Dec 2027
- How long will I take part?
- 2 Days
- Phase
- Observational
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 35 years
- All sexes
- Healthy volunteers accepted
- Adult
Study population: The population being evaluated by the protocol consists of a convenience sample of individuals with Down syndrome (Ds) between the ages of 18 and 35 years old, and a group of control participants without Ds matched for age and sex, living in the community. 43 participants will be enrolled in the study at UNLV: 23 individuals with Down syndrome and 23 individuals without Down syndrome.
Who may be able to join
- between 18 and 35 years old
- generally healthy
- sedentary (defined as being involved in less than 30 minutes of moderately-intense physical activity per day)
- Additionally, for the participants with Down syndrome:
- diagnosis of Down syndrome trisomy 21
- normal thyroid function or stable thyroid function (and medications) for at least 6 months.
Who cannot join
- unresolved congenital heart disease;
- atherosclerotic or other vascular disease (such as blood clot history or clotting disorders);
- asthma or other pulmonary disease;
- hypertension (defined as BP >140/90 mmHg); blood pressure below 90/60 mmHg;
- history of pre-syncope or syncope;
- diabetes (defined as glycated hemoglobin (HbA1c) of >7.5% or use of glucose-lowering medication);
Show all 13Show fewer
- severe obesity (defined as body mass index (BMI) >40);
- heart medications affecting heart rate, blood pressure, or arterial function, including blood thinners; anti-inflammatory medication, including Nonsteroidal anti-inflammatory drugs (NSAIDS);
- current smoking;
- currently pregnant or planning to become pregnant during the study period;
- currently breastfeeding;
- unable or unwilling to use an acceptable method of contraception during the study timeframe;
- positive pregnancy test at screening.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
United States1 site, 1 recruiting
- Recruiting
University of Nevada Las Vegas - UNLV
Las Vegas, Nevada, 89154
Thessa Hilgenkamp, PhD, (702) 8951055, thessa.hilgenkamp@unlv.edu
Andre Rocha, MSc, 7255877643, andre.rocha@unlv.edu
About this study
Adults with Down syndrome (Ds) are often thought to have a lower risk of heart and blood vessel disease because they tend to have lower blood pressure (BP) and fewer heart attacks than people without Ds. However, recent research suggests that heart and blood vessel diseases, including stroke, are becoming a more common cause of death in adults with Ds as life expectancy increases. Despite these findings, studies examining heart and blood vessel health in adults with Ds have produced mixed results, making it difficult to determine their true risk and whether preventive strategies are needed. This study will investigate the health of blood vessels in adults with Ds and compare the results with those of adults without Ds. Healthy blood vessels are important because they help deliver blood and oxygen throughout the body. Changes in blood vessel function and stiffness can occur with aging and may increase the risk of heart disease, stroke, kidney disease, and memory problems. The study aims to determine whether adults with Ds experience changes in blood vessel health that may place them at increased cardiovascular risk. Specifically, the study will: (1) Examine how well blood vessels function in adults with Ds; (2) Measure the stiffness of arteries in adults with Ds; (3) Compare two methods used to assess blood vessel function to determine whether a simpler exercise-based test provides results similar to a commonly used standard test. The findings may improve understanding of cardiovascular risk in adults with Ds and help guide future strategies to promote healthy aging in this population.
Read the detailed description
This proposal challenges the conventional wisdom that adults with Down syndrome (Ds) are at a lower risk for cardiovascular disease (CVD) because they have low blood pressure and fewer heart attacks than their peers without DS. Recent studies show a larger and increasing contribution of non-congenital CVD (including stroke) to mortality in adults with Ds, likely due to the increased life expectancy. Despite this, studies on traditional cardiovascular risk indicators in adults with DS are conflicting. This currently results in limited urgency for implementing risk-lowering strategies. To address this gap in knowledge and methodology, our overall aim is to demonstrate accelerated vascular aging in adults with Ds, defined by age-related yet Ds-specific endothelial dysfunction and arterial stiffness. Vascular aging directly measures the disease progression towards organ damage, such as the brain and the kidneys, which leads to cardiovascular disease, stroke, and Alzheimer's disease (AD) in the general population. Adults with Ds experience excessive syndrome-specific chronic vascular adaptations, which may accelerate vascular aging. However, this has not yet been investigated.
This project aims to provide a more direct and accurate measure to determine cardiovascular risk by comprehensively characterizing vascular health in adults with Ds compared to adults without Ds.
Aim 1: To identify the effect of Ds on endothelial function. Aim 2: To identify the impact of Ds on arterial stiffness. Aim 3: To compare measurements of endothelial function using a hand grip (HG) exercise protocol and the gold standard flow-mediated dilation protocol (FMD).
A cross-sectional research design is used for all aims and includes a comprehensive evaluation of endothelial function and arterial stiffness. Both participants with Ds and a sex-matched control group of participants without Ds or other intellectual disabilities (from here on, control participants) will be included.
Familiarization. The investigators involve parents/caregivers to provide a supportive environment for participants and to enhance the parent's/caregiver's understanding of the research with videos and practice sessions.
Description of data collection visits. Data collection will be completed in two study visits of maximal 2h each. The investigators will first obtain a signed informed consent form explaining our study procedures, potential risks, and benefits of the study from the participants and/or their legally authorized representative, if present. During the first data collection visit, after discussing the study and potential questions, participants and/or their legally authorized representative will complete the International Physical Activity Questionnaire (IPAQ) to confirm eligibility. Participants will be tested in a postprandial state (>3 h) and will refrain from drinking or eating caffeine and drinking alcohol and from exercise 24 h before both the test days. Females will be studied during the first 3-5 days of menses to control for hormonal variation. Baseline measurements will include anthropometric assessments of height, weight, and circumference. Body composition will be measured with a dual x-ray absorptiometry (DEXA) scan to record forearm composition and mass. For arterial stiffness assessment, participants will lie down while their arterial Pulse Wave Velocity (PWV) and Augmentation Index are measured using a brachial blood pressure monitor (Mobil-O-Graph) and carotid-femoral tonometry (PulsePen). Carotid Beta-Stiffness and intima-media thickness (IMT) will be evaluated via carotid ultrasonography (Hitachi Arietta 70). The second visit will include an assessment of endothelial function. Participants will lie down and perform a 2-minute isometric hand grip test (HG) at 30% of maximum voluntary contraction (MVC), followed by a flow-mediated dilation (FMD) protocol with a cuff occlusion of 50 mmHg above systolic blood pressure on the forearm for 5 minutes. Brachial artery dilation and blood flow will be assessed after HG and FMD using high-resolution ultrasonography (Arietta 70, Hitachi, Tokyo, Japan).
- Conditions
- Down Syndrome (Trisomy 21)
- Keywords
- Down Syndrome, Trisomy 21, Arterial stiffness, Endothelial function, vascular function, ultrasonography, arterial doppler
- Medical subject headings
- Down Syndrome
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
| Study group | Role | What they receive |
|---|---|---|
| Down Syndrome | Adults with Down Syndrome | |
| Control group | Age- and sex-matched adults without Down Syndrome |
What is being measured
The primary outcome is the main question the study is designed to answer.
Carotid-femoral pulse wave velocity (PWV).
PWV (m/s) will be measured using small, non-invasive pressure-sensitive transducers that record distension waveforms over superficial arteries like the carotid and femoral artery (PulsePen® DiaTecne - Italia).
Measured: Through study completion, on average 4 hours
Secondary outcomes (5)
Augmentation index
Defined as the ratio of Augmentation Pressure (AP) to the total Pulse Pressure (PP), expressed as %. It will be measured using small, non-invasive pressure-sensitive transducers that record distension waveforms over superficial arteries (PulsePen® DiaTecne - Italia).
Measured: Through study completion, on average 4 hours.
Carotid Beta-stiffness
The carotid Beta-stiffness index is a unitless measurement. It quantifies the intrinsic stiffness of the common carotid artery using high-definition ultrasound (Hitachi Arietta 70 system, Tokyo, Japan).
Measured: Through study completion, on average 4 hours.
Intima-Media Thickness
An ultrasound-based assessment of intima-media thickness (IMT) for the carotid artery. Thickness will be calculated as the distance (mm) from the leading edge of the intima to the beginning of the adventitial layer of the top and bottom walls.
Measured: Through study completion, on average 4 hours.
Change in Blood Flow after isometric hand grip exercise.
Participants will perform a 2-minute isometric hand grip exercise at 30% of MVC. Brachial artery blood flow (mL/min) will be assessed using high-resolution ultrasonography (Arietta 70, Hitachi, Tokyo, Japan) and expressed as a percentage of baseline measurements, normalized to forearm lean mass.
Measured: Through study completion, on average 4 hours.
Change in Blood Flow after occlusion
Participants will undergo a flow-mediated dilation (FMD) protocol, in which a pneumatic cuff will be placed around the forearm and inflated to 50 mmHg above systolic levels for 5 minutes. Brachial artery blood flow (mL/min) will be assessed using high-resolution ultrasonography (Arietta 70, Hitachi, Tokyo, Japan) and expressed as a percentage of baseline measurements, normalized to forearm lean mass.
Measured: Through study completion, on average 4 hours.
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted5 Jun 2026
- Study start9 Apr 2026
- Primary completion31 May 2027 (estimated)
- Study completion31 Dec 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Down Syndrome (Trisomy 21)Studies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Other
- Time perspective
- Cross-sectional
- Enrolment
- 46 participants (estimated)
- Target duration
- 2 Days
Sponsor and investigators
- Lead sponsor
- University of Nevada, Las Vegas
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07630207
- Sponsor's protocol ID
- UNLV-2025-360
- Acronym
- VDS
- Status last verified
- Jun 2026
- First submitted
- 1 Jun 2026
- Last updated
- 2 Oct 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No: De-identified IPD will be made available to other researchers upon request.
Study at a glance
From the registry record, last updated by the sponsor on 2 Oct 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Vascular Function in Adults With Down Syndrome
- ClinicalTrials.gov ID
- NCT07630207
- Acronym / sponsor ID
- VDS / UNLV-2025-360
- Conditions
- Down Syndrome (Trisomy 21)
- Keywords
- Down Syndrome, Trisomy 21, Arterial stiffness, Endothelial function, vascular function, ultrasonography, arterial doppler
- Study type
- Observational
- Recruitment status
- Recruiting
- Enrolment
- 46 participants (estimated)
- Lead sponsor
- University of Nevada, Las VegasUniversity, hospital or other
- Study start
- 9 Apr 2026 (actual)
- Primary completion
- 31 May 2027 (estimated)
- Study completion
- 31 Dec 2027 (estimated)
- First posted
- 5 Jun 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Adults with Down syndrome (Ds) are often thought to have a lower risk of heart and blood vessel disease because they tend to have lower blood pressure (BP) and fewer heart attacks than people without Ds. However, recent research suggests that heart and blood vessel diseases, including stroke, are becoming a more common cause of death in adults with Ds as life expectancy increases. Despite these findings, studies examining heart and blood vessel health in adults with Ds have produced mixed results, making it difficult to determine their true risk and whether preventive strategies are needed. This study will investigate the health of blood vessels in adults with Ds and compare the results with those of adults without Ds. Healthy blood vessels are important because they help deliver blood and oxygen throughout the body. Changes in blood vessel function and stiffness can occur with aging and may increase the risk of heart disease, stroke, kidney disease, and memory problems. The study aims to determine whether adults with Ds experience changes in blood vessel health that may place them at increased cardiovascular risk. Specifically, the study will: (1) Examine how well blood vessels function in adults with Ds; (2) Measure the stiffness of arteries in adults with Ds; (3) Compare two methods used to assess blood vessel function to determine whether a simpler exercise-based test provides results similar to a commonly used standard test. The findings may improve understanding of cardiovascular risk in adults with Ds and help guide future strategies to promote healthy aging in this population.
Detailed description
This proposal challenges the conventional wisdom that adults with Down syndrome (Ds) are at a lower risk for cardiovascular disease (CVD) because they have low blood pressure and fewer heart attacks than their peers without DS. Recent studies show a larger and increasing contribution of non-congenital CVD (including stroke) to mortality in adults with Ds, likely due to the increased life expectancy. Despite this, studies on traditional cardiovascular risk indicators in adults with DS are conflicting. This currently results in limited urgency for implementing risk-lowering strategies. To address this gap in knowledge and methodology, our overall aim is to demonstrate accelerated vascular aging in adults with Ds, defined by age-related yet Ds-specific endothelial dysfunction and arterial stiffness. Vascular aging directly measures the disease progression towards organ damage, such as the brain and the kidneys, which leads to cardiovascular disease, stroke, and Alzheimer's disease (AD) in the general population. Adults with Ds experience excessive syndrome-specific chronic vascular adaptations, which may accelerate vascular aging. However, this has not yet been investigated.
This project aims to provide a more direct and accurate measure to determine cardiovascular risk by comprehensively characterizing vascular health in adults with Ds compared to adults without Ds.
Aim 1: To identify the effect of Ds on endothelial function. Aim 2: To identify the impact of Ds on arterial stiffness. Aim 3: To compare measurements of endothelial function using a hand grip (HG) exercise protocol and the gold standard flow-mediated dilation protocol (FMD).
A cross-sectional research design is used for all aims and includes a comprehensive evaluation of endothelial function and arterial stiffness. Both participants with Ds and a sex-matched control group of participants without Ds or other intellectual disabilities (from here on, control participants) will be included.
Familiarization. The investigators involve parents/caregivers to provide a supportive environment for participants and to enhance the parent's/caregiver's understanding of the research with videos and practice sessions.
Description of data collection visits. Data collection will be completed in two study visits of maximal 2h each. The investigators will first obtain a signed informed consent form explaining our study procedures, potential risks, and benefits of the study from the participants and/or their legally authorized representative, if present. During the first data collection visit, after discussing the study and potential questions, participants and/or their legally authorized representative will complete the International Physical Activity Questionnaire (IPAQ) to confirm eligibility. Participants will be tested in a postprandial state (>3 h) and will refrain from drinking or eating caffeine and drinking alcohol and from exercise 24 h before both the test days. Females will be studied during the first 3-5 days of menses to control for hormonal variation. Baseline measurements will include anthropometric assessments of height, weight, and circumference. Body composition will be measured with a dual x-ray absorptiometry (DEXA) scan to record forearm composition and mass. For arterial stiffness assessment, participants will lie down while their arterial Pulse Wave Velocity (PWV) and Augmentation Index are measured using a brachial blood pressure monitor (Mobil-O-Graph) and carotid-femoral tonometry (PulsePen). Carotid Beta-Stiffness and intima-media thickness (IMT) will be evaluated via carotid ultrasonography (Hitachi Arietta 70). The second visit will include an assessment of endothelial function. Participants will lie down and perform a 2-minute isometric hand grip test (HG) at 30% of maximum voluntary contraction (MVC), followed by a flow-mediated dilation (FMD) protocol with a cuff occlusion of 50 mmHg above systolic blood pressure on the forearm for 5 minutes. Brachial artery dilation and blood flow will be assessed after HG and FMD using high-resolution ultrasonography (Arietta 70, Hitachi, Tokyo, Japan).
Study design
- Observational model
- Other
- Time perspective
- Cross-sectional
- Target follow-up
- 2 Days
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Down Syndrome | – | –Adults with Down Syndrome |
| Control group | – | –Age- and sex-matched adults without Down Syndrome |
Who may qualify
- Ages
- 18 to 35 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
- Study population
- The population being evaluated by the protocol consists of a convenience sample of individuals with Down syndrome (Ds) between the ages of 18 and 35 years old, and a group of control participants without Ds matched for age and sex, living in the community. 43 participants will be enrolled in the study at UNLV: 23 individuals with Down syndrome and 23 individuals without Down syndrome.
Key inclusion criteria (6 listed)
- between 18 and 35 years old
- generally healthy
- sedentary (defined as being involved in less than 30 minutes of moderately-intense physical activity per day)
- diagnosis of Down syndrome trisomy 21
- normal thyroid function or stable thyroid function (and medications) for at least 6 months.
Key exclusion criteria (13 listed)
- unresolved congenital heart disease;
- atherosclerotic or other vascular disease (such as blood clot history or clotting disorders);
- asthma or other pulmonary disease;
- hypertension (defined as BP >140/90 mmHg); blood pressure below 90/60 mmHg;
- history of pre-syncope or syncope;
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Primary outcome
Carotid-femoral pulse wave velocity (PWV).
Time frame: Through study completion, on average 4 hours
PWV (m/s) will be measured using small, non-invasive pressure-sensitive transducers that record distension waveforms over superficial arteries like the carotid and femoral artery (PulsePen® DiaTecne - Italia).
5 secondary outcomes
Augmentation index
Time frame: Through study completion, on average 4 hours.
Carotid Beta-stiffness
Time frame: Through study completion, on average 4 hours.
Intima-Media Thickness
Time frame: Through study completion, on average 4 hours.
Change in Blood Flow after isometric hand grip exercise.
Time frame: Through study completion, on average 4 hours.
Change in Blood Flow after occlusion
Time frame: Through study completion, on average 4 hours.
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 2 Oct 2026.
- Individual participant dataSharing planned: No. De-identified IPD will be made available to other researchers upon request.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Down Syndrome (Trisomy 21), run by University of Nevada, Las Vegas at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 6 inclusion and 13 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 2 Oct 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Thessa Hilgenkamp, PhD ((702) 8951055, thessa.hilgenkamp@unlv.edu), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Carotid-femoral pulse wave velocity (PWV). (time frame: Through study completion, on average 4 hours). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 2 Oct 2026.