xml: <clinical_study>
    <!-- This xml conforms to an XML Schema at:
      https://clinicaltrials.gov/ct2/html/images/info/public.xsd -->
    <required_header>
      <download_date>ClinicalTrials.gov processed this data on September 20, 2023</download_date>
      <link_text>Link to the current ClinicalTrials.gov record.</link_text>
      <url>https://clinicaltrials.gov/ct2/show/NCT05995223</url>
    </required_header>
    <id_info>
      <org_study_id>UNLV-2022-489</org_study_id>
      <nct_id>NCT05995223</nct_id>
    </id_info>
    <brief_title>Oxygen Uptake Kinetics During Submaximal Exercise in Adults With Down Syndrome</brief_title>
    <official_title>Oxygen Uptake Kinetics During Submaximal Exercise in Adults With Down Syndrome</official_title>
    <sponsors>
      <lead_sponsor>
        <agency>University of Nevada, Las Vegas</agency>
        <agency_class>Other</agency_class>
      </lead_sponsor>
    </sponsors>
    <source>University of Nevada, Las Vegas</source>
    <oversight_info>
      <has_dmc>No</has_dmc>
      <is_fda_regulated_drug>No</is_fda_regulated_drug>
      <is_fda_regulated_device>No</is_fda_regulated_device>
    </oversight_info>
    <brief_summary>
      <textblock>
        This study aims to compare the rate at which oxygen uptake adapts to submaximal, moderate&#xD;
        intensity exercise (oxygen uptake kinetics) between adults with and without Down syndrome, to&#xD;
        determine the contribution of oxygen uptake kinetics to exercise intolerance of adults with&#xD;
        Down syndrome. Additionally, the study will investigate the role of oxygen delivery (by the&#xD;
        cardiovascular circuit) and oxygen utilization (in the mitochondria) on the oxygen uptake&#xD;
        kinetics of adults with Down syndrome to identify specific areas which adults with Down&#xD;
        syndrome could benefit from targeting during exercise training. Overall, this study aims to&#xD;
        contribute to the knowledge on the exercise capacity of adults with Down syndrome, in order&#xD;
        to improve the way adults with Down syndrome participate in and benefit from exercise.&#xD;
  &#xD;
        Participants will perform a maximal exercise test on a treadmill, and walk on a treadmill at&#xD;
        a submaximal, moderate intensity speed and incline, during which oxygen uptake at the lungs,&#xD;
        cardiac output, and oxygen utilization in the muscle will be measured.&#xD;
      </textblock>
    </brief_summary>
    <detailed_description>
      <textblock>
        Down syndrome (Ds) is the most common chromosomal disorder, affecting approximately 1 in&#xD;
        every 800 live births in the US. In addition to a number of comorbidities, individuals with&#xD;
        Ds have low cardiorespiratory fitness. Their low fitness cannot be explained by low levels of&#xD;
        physical activity, lack of motivation, or lack of understanding of the test, but rather has a&#xD;
        physiological cause. Autonomic dysfunction has been identified as one major contributor to&#xD;
        the low cardiorespiratory fitness in individuals with Ds, but it does not fully explain the&#xD;
        phenomenon.&#xD;
  &#xD;
        Cardiorespiratory fitness is determined by the capacity of the body to produce energy, which&#xD;
        largely relies on the ability to take up, deliver, and use oxygen. This process of oxygen&#xD;
        transport is governed by the pulmonary, cardiovascular, and muscular system, and the degree&#xD;
        to which they work together. At the start of exercise, these three systems respond in a&#xD;
        delayed pattern, requiring the body to compensate energy production through anaerobic means,&#xD;
        which negatively affect one's exercise tolerance. Thus, the quicker the adaptation of these&#xD;
        three systems (i.e. the quicker their kinetics), the better one's ability to perform and&#xD;
        tolerate exercise.&#xD;
  &#xD;
        The rate of adaption of these oxygen transport system can be quantified by assessing oxygen&#xD;
        uptake (pulmonary), cardiac output (cardiovascular), and mitochondrial oxygen utilization&#xD;
        (muscle) kinetics, which all show a delayed, exponential increase towards steady state at the&#xD;
        start of moderate intensity exercise. The kinetics of these three systems have never been&#xD;
        assessed in individuals with Ds, and could provide valuable insights into their low&#xD;
        cardiorespiratory fitness and reduced exercise tolerance.&#xD;
  &#xD;
        The aim of this research proposal is therefore to determine the differences in kinetics of&#xD;
        oxygen uptake, cardiac output, and mitochondrial oxygen utilization between individuals with&#xD;
        and without Ds to better understand the underlying physiology and potentially improve healthy&#xD;
        by using this knowledge for exercise interventions.&#xD;
  &#xD;
        Overall aim: to better understand the relation between oxygen uptake kinetics and&#xD;
        cardiorespiratory fitness in individuals with Ds.&#xD;
  &#xD;
        Aim 1: To compare the rate of oxygen uptake, cardiac output, and mitochondrial oxygen&#xD;
        utilization kinetics in response to submaximal, moderate intensity exercise between adults&#xD;
        with and without Ds.&#xD;
  &#xD;
        Aim 2: To determine the relation between the rate of oxygen uptake kinetics and the peak&#xD;
        oxygen uptake of individuals with Ds.&#xD;
  &#xD;
        Determining how oxygen transport affects individuals with Ds during exercise could&#xD;
        potentially give more direction into designing exercise sessions and interventions, as their&#xD;
        oxygen transport system potentially might need more time to reach the required working level.&#xD;
  &#xD;
        General study design. Participants will complete two study visits, during which their&#xD;
        cardiorespiratory capacities will be tested using two different treadmill protocols.&#xD;
        Familiarization with all study personnel and procedures will take place before actual&#xD;
        measurements are performed.&#xD;
  &#xD;
        Description data collection visits. Participants will be tested in a postprandial state (&gt;3&#xD;
        h) on 2 separate days (separated by at least 48 hours, but no more than 2 weeks) and will&#xD;
        refrain from exercise, alcohol and caffeine for at least 24 h before each study visit. During&#xD;
        the first visit, height, weight, and circumferences will be measured. Body composition will&#xD;
        be measured using dual energy X-ray absorptiometry (DEXA), and echocardiography will be&#xD;
        performed to determined aortic diameter and to screen for any potential residual cardiac&#xD;
        deficits common in individuals with Ds. Lastly, participants will perform a graded maximal&#xD;
        treadmill exercise test to determine peak oxygen uptake (VO2peak) and to determine the&#xD;
        submaximal exercise intensity for the second visit.&#xD;
  &#xD;
        The second visit will have participants walk on an intensity associated with 80% of their&#xD;
        ventilatory threshold for six minutes while pulmonary oxygen uptake (using breath-by-breath&#xD;
        gas exchange analysis), cardiac output (using beat-to-beat blood pressure measurement), and&#xD;
        muscle oxygenation (using near-infrared spectroscopy (NIRS)) is measured. This bout of six&#xD;
        minutes will be repeated four times, with 10 minutes rest in between. The four bouts will be&#xD;
        used to average the three signals, which improves the calculation of kinetic parameters.&#xD;
  &#xD;
        Familiarization. Parents/care givers are involved in order to provide a supportive&#xD;
        environment for participants and to enhance the parent/caregiver understanding of the&#xD;
        research. Prior to study initiation, photographs and video clips of the laboratory and study&#xD;
        equipment will be provided to help the participants become comfortable with the laboratory&#xD;
        environment and equipment, and the informed consent information is sent to the participants&#xD;
        and their parents/care-givers for their review. Familiarization for the participants with&#xD;
        Down syndrome will be divided in two parts: they will practice and become accustomed with the&#xD;
        treadmill and the equipment for the graded maximal exercise test (very start of the first&#xD;
        visit), and they will practice and become accustomed with the procedures for the submaximal&#xD;
        exercise protocol (start of the second visit).&#xD;
      </textblock>
    </detailed_description>
    <overall_status>Recruiting</overall_status>
    <start_date type="Anticipated">September 2023</start_date>
    <completion_date type="Anticipated">December 2024</completion_date>
    <primary_completion_date type="Anticipated">July 2024</primary_completion_date>
    <phase>N/A</phase>
    <study_type>Interventional</study_type>
    <has_expanded_access>No</has_expanded_access>
    <study_design_info>
      <allocation>Non-Randomized</allocation>
      <intervention_model>Parallel Assignment</intervention_model>
      <primary_purpose>Screening</primary_purpose>
      <masking>None (Open Label)</masking>
    </study_design_info>
    <primary_outcome>
      <measure>Oxygen uptake kinetics</measure>
      <time_frame>Through study completion, on average 4 hours</time_frame>
      <description>The finite rate at which oxygen uptake (measured with breath-by-breath gas exchange analysis at the mouth) adapts to a (submaximal) increase in exercise intensity, primarily captured by time constant tau, which describes the time needed to reach 63% of the required, steady state oxygen uptake</description>
    </primary_outcome>
    <secondary_outcome>
      <measure>Cardiac output kinetics</measure>
      <time_frame>Through study completion, on average 4 hours</time_frame>
      <description>The finite rate at which cardiac output (calculated from beat-to-beat blood pressure waves) adapts to a (submaximal) increase in exercise intensity, primarily captured by time constant tau, which describes the time needed to reach 63% of the required, steady state cardiac output</description>
    </secondary_outcome>
    <secondary_outcome>
      <measure>Muscle deoxygenation kinetics</measure>
      <time_frame>Through study completion, on average 4 hours</time_frame>
      <description>The finite rate at which muscle oxygen utilization (measured as the production of deoxyhemoglobin at the muscle) adapts to a (submaximal) increase in exercise intensity, primarily captured by time constant tau, which describes the time needed to reach 63% of the required, steady state muscle oxygen utilization</description>
    </secondary_outcome>
    <secondary_outcome>
      <measure>Steady-state cardiac output</measure>
      <time_frame>Through study completion, on average 4 hours</time_frame>
      <description>Steady state cardiac output during standing rest and submaximal exercise (in L/min)</description>
    </secondary_outcome>
    <secondary_outcome>
      <measure>Absolute peak oxygen uptake</measure>
      <time_frame>Through study completion, on average 4 hours</time_frame>
      <description>Peak oxygen uptake (VO2peak; expressed in L/min)</description>
    </secondary_outcome>
    <secondary_outcome>
      <measure>Relative peak oxygen uptake (corrected for total body mass)</measure>
      <time_frame>Through study completion, on average 4 hours</time_frame>
      <description>Peak oxygen uptake (VO2peak; expressed in ml/kg/min)</description>
    </secondary_outcome>
    <secondary_outcome>
      <measure>Relative peak oxygen uptake (corrected for lean body mass)</measure>
      <time_frame>Through study completion, on average 4 hours</time_frame>
      <description>Peak oxygen uptake (VO2peak; expressed in L=mL/kg lean body mass/min)</description>
    </secondary_outcome>
    <secondary_outcome>
      <measure>Ventilatory threshold (L/min)</measure>
      <time_frame>Through study completion, on average 4 hours</time_frame>
      <description>The threshold where ventilation starts to increase at a faster rate than oxygen uptake during a graded maximal exercise test (expressed in L/min)</description>
    </secondary_outcome>
    <secondary_outcome>
      <measure>Ventilatory threshold (%VO2peak)</measure>
      <time_frame>Through study completion, on average 4 hours</time_frame>
      <description>The threshold where ventilation starts to increase at a faster rate than oxygen uptake during a graded maximal exercise test (expressed as a percentage of VO2peak)</description>
    </secondary_outcome>
    <secondary_outcome>
      <measure>Stroke volume</measure>
      <time_frame>Through study completion, on average 4 hours</time_frame>
      <description>Stroke volume (mL)</description>
    </secondary_outcome>
    <secondary_outcome>
      <measure>Heart rate</measure>
      <time_frame>Through study completion, on average 4 hours</time_frame>
      <description>Heart rate (in bpm)</description>
    </secondary_outcome>
    <secondary_outcome>
      <measure>Oxygen uptake efficiency slope</measure>
      <time_frame>Through study completion, on average 4 hours</time_frame>
      <description>The slope between oxygen uptake (L/min) and the common logarithm of minute ventilation (L/min) during a graded maximal exercise test</description>
    </secondary_outcome>
    <secondary_outcome>
      <measure>Ve/VCO2 slope</measure>
      <time_frame>Through study completion, on average 4 hours</time_frame>
      <description>The slope between minute ventilation (Ve; L/min) and carbon dioxide production (VCO2; L/min) during a graded maximal exercise test</description>
    </secondary_outcome>
    <secondary_outcome>
      <measure>Lean body mass</measure>
      <time_frame>Through study completion, on average 4 hours</time_frame>
      <description>Lean body mass determined with Dual Energy X-ray Absorptiometry (DXA) scan in kg</description>
    </secondary_outcome>
    <number_of_arms>2</number_of_arms>
    <enrollment type="Anticipated">30</enrollment>
    <condition>Down Syndrome</condition>
    <arm_group>
      <arm_group_label>Down syndrome</arm_group_label>
      <arm_group_type>Experimental</arm_group_type>
      <description>Participants will complete a submaximal walking protocol on a motorized treadmill, which consists of 4 times 6 minutes of walking at a moderate intensity speed and incline while their breathing, cardiac output, and muscle oxygen use is measured, with 10 minutes rest in between each bout.</description>
    </arm_group>
    <arm_group>
      <arm_group_label>control without Down syndrome</arm_group_label>
      <arm_group_type>Experimental</arm_group_type>
      <description>This group of age- and sex-matched participants without Down syndrome will undergo the same testing as participants with Down syndrome</description>
    </arm_group>
    <intervention>
      <intervention_type>Other</intervention_type>
      <intervention_name>Submaximal exercise protocol</intervention_name>
      <description>Participants will complete a submaximal walking protocol on a motorized treadmill, which consists of 4 times 6 minutes of walking at a moderate intensity speed and incline while their breathing, cardiac output, and muscle oxygen use is measured, with 10 minutes rest in between each bout.</description>
      <arm_group_label>Down syndrome</arm_group_label>
      <arm_group_label>control without Down syndrome</arm_group_label>
    </intervention>
    <eligibility>
      <criteria>
        <textblock>
          Inclusion Criteria:&#xD;
  &#xD;
            -  low active (defined as being involved in less than 30 minutes of moderately-intense&#xD;
               physical activity per day);&#xD;
  &#xD;
            -  diagnosis with Down syndrome trisomy 21 (Down syndrome group only);&#xD;
  &#xD;
            -  normal thyroid function or stable thyroid function (with medications) for at least 6&#xD;
               months (Down syndrome group only).&#xD;
  &#xD;
          Exclusion Criteria:&#xD;
  &#xD;
            -  asthma or other pulmonary disease;&#xD;
  &#xD;
            -  severe obesity (defined as BMI &gt;40);&#xD;
  &#xD;
            -  uncontrolled hypertension (defined as blood pressure &gt;130/80 mmHg);&#xD;
  &#xD;
            -  congenital heart disease;&#xD;
  &#xD;
            -  diabetes (defined as Hba1c of &gt;7.5% or use of glucose lowering medication);&#xD;
  &#xD;
            -  current smoking;&#xD;
  &#xD;
            -  pregnancy.&#xD;
        </textblock>
      </criteria>
      <gender>All</gender>
      <minimum_age>18 Years</minimum_age>
      <maximum_age>35 Years</maximum_age>
      <healthy_volunteers>Accepts Healthy Volunteers</healthy_volunteers>
    </eligibility>
    <overall_official>
      <last_name>Victor DY Beck, MS</last_name>
      <role>Principal Investigator</role>
      <affiliation>University of Nevada, Las Vegas</affiliation>
    </overall_official>
    <overall_contact>
      <last_name>Victor DY Beck, MS</last_name>
      <phone>702-895-3003</phone>
      <email>victor.beck@unlv.edu</email>
    </overall_contact>
    <overall_contact_backup>
      <last_name>Thessa IM Hilgenkamp, PhD</last_name>
      <phone>702-895-3003</phone>
      <email>thessa.hilgenkamp@unlv.edu</email>
    </overall_contact_backup>
    <location>
      <facility>
        <name>University of Nevada, Las Vegas</name>
        <address>
          <city>Las Vegas</city>
          <state>Nevada</state>
          <zip>89154</zip>
          <country>United States</country>
        </address>
      </facility>
      <status>Recruiting</status>
      <contact>
        <last_name>Victor DY Beck, MS</last_name>
        <phone>702-895-3003</phone>
        <email>victor.beck@unlv.edu</email>
      </contact>
    </location>
    <location_countries>
      <country>United States</country>
    </location_countries>
    <verification_date>September 2023</verification_date>
    <study_first_submitted>June 29, 2023</study_first_submitted>
    <study_first_submitted_qc>August 15, 2023</study_first_submitted_qc>
    <study_first_posted type="Actual">August 16, 2023</study_first_posted>
    <last_update_submitted>September 12, 2023</last_update_submitted>
    <last_update_submitted_qc>September 12, 2023</last_update_submitted_qc>
    <last_update_posted type="Actual">September 14, 2023</last_update_posted>
    <responsible_party>
      <responsible_party_type>Principal Investigator</responsible_party_type>
      <investigator_affiliation>University of Nevada, Las Vegas</investigator_affiliation>
      <investigator_full_name>Victor Beck</investigator_full_name>
      <investigator_title>Graduate Research Assistant</investigator_title>
    </responsible_party>
    <keyword>Down syndrome</keyword>
    <keyword>cardiorespiratory fitness</keyword>
    <keyword>oxygen uptake</keyword>
    <keyword>cardiac output</keyword>
    <keyword>mitochondrial oxygen utilization</keyword>
    <condition_browse>
      <!-- CAUTION:  The following MeSH terms are assigned with an imperfect algorithm            -->
      <mesh_term>Down Syndrome</mesh_term>
      <mesh_term>Syndrome</mesh_term>
    </condition_browse>
    <patient_data>
      <sharing_ipd>No</sharing_ipd>
      <ipd_description>De-identified IPD will be made available to other researchers upon request.</ipd_description>
    </patient_data>
    <!-- Results have not yet been posted for this study                                          -->
  </clinical_study>
  
  
text: download date: ClinicalTrials.gov processed this data on September 20, 2023
  link text: Link to the current ClinicalTrials.gov record.
  url: https://clinicaltrials.gov/ct2/show/NCT05995223
  org study id: UNLV-2022-489
  nct id: NCT05995223
  lead sponsor: 
  has dmc: No
  is fda regulated drug: No
  is fda regulated device: No
  This study aims to compare the rate at which oxygen uptake adapts to submaximal, moderate
        intensity exercise (oxygen uptake kinetics) between adults with and without Down syndrome, to
        determine the contribution of oxygen uptake kinetics to exercise intolerance of adults with
        Down syndrome. Additionally, the study will investigate the role of oxygen delivery (by the
        cardiovascular circuit) and oxygen utilization (in the mitochondria) on the oxygen uptake
        kinetics of adults with Down syndrome to identify specific areas which adults with Down
        syndrome could benefit from targeting during exercise training. Overall, this study aims to
        contribute to the knowledge on the exercise capacity of adults with Down syndrome, in order
        to improve the way adults with Down syndrome participate in and benefit from exercise.
  
        Participants will perform a maximal exercise test on a treadmill, and walk on a treadmill at
        a submaximal, moderate intensity speed and incline, during which oxygen uptake at the lungs,
        cardiac output, and oxygen utilization in the muscle will be measured.
  Down syndrome (Ds) is the most common chromosomal disorder, affecting approximately 1 in
        every 800 live births in the US. In addition to a number of comorbidities, individuals with
        Ds have low cardiorespiratory fitness. Their low fitness cannot be explained by low levels of
        physical activity, lack of motivation, or lack of understanding of the test, but rather has a
        physiological cause. Autonomic dysfunction has been identified as one major contributor to
        the low cardiorespiratory fitness in individuals with Ds, but it does not fully explain the
        phenomenon.
  
        Cardiorespiratory fitness is determined by the capacity of the body to produce energy, which
        largely relies on the ability to take up, deliver, and use oxygen. This process of oxygen
        transport is governed by the pulmonary, cardiovascular, and muscular system, and the degree
        to which they work together. At the start of exercise, these three systems respond in a
        delayed pattern, requiring the body to compensate energy production through anaerobic means,
        which negatively affect one's exercise tolerance. Thus, the quicker the adaptation of these
        three systems (i.e. the quicker their kinetics), the better one's ability to perform and
        tolerate exercise.
  
        The rate of adaption of these oxygen transport system can be quantified by assessing oxygen
        uptake (pulmonary), cardiac output (cardiovascular), and mitochondrial oxygen utilization
        (muscle) kinetics, which all show a delayed, exponential increase towards steady state at the
        start of moderate intensity exercise. The kinetics of these three systems have never been
        assessed in individuals with Ds, and could provide valuable insights into their low
        cardiorespiratory fitness and reduced exercise tolerance.
  
        The aim of this research proposal is therefore to determine the differences in kinetics of
        oxygen uptake, cardiac output, and mitochondrial oxygen utilization between individuals with
        and without Ds to better understand the underlying physiology and potentially improve healthy
        by using this knowledge for exercise interventions.
  
        Overall aim: to better understand the relation between oxygen uptake kinetics and
        cardiorespiratory fitness in individuals with Ds.
  
        Aim 1: To compare the rate of oxygen uptake, cardiac output, and mitochondrial oxygen
        utilization kinetics in response to submaximal, moderate intensity exercise between adults
        with and without Ds.
  
        Aim 2: To determine the relation between the rate of oxygen uptake kinetics and the peak
        oxygen uptake of individuals with Ds.
  
        Determining how oxygen transport affects individuals with Ds during exercise could
        potentially give more direction into designing exercise sessions and interventions, as their
        oxygen transport system potentially might need more time to reach the required working level.
  
        General study design. Participants will complete two study visits, during which their
        cardiorespiratory capacities will be tested using two different treadmill protocols.
        Familiarization with all study personnel and procedures will take place before actual
        measurements are performed.
  
        Description data collection visits. Participants will be tested in a postprandial state (>3
        h) on 2 separate days (separated by at least 48 hours, but no more than 2 weeks) and will
        refrain from exercise, alcohol and caffeine for at least 24 h before each study visit. During
        the first visit, height, weight, and circumferences will be measured. Body composition will
        be measured using dual energy X-ray absorptiometry (DEXA), and echocardiography will be
        performed to determined aortic diameter and to screen for any potential residual cardiac
        deficits common in individuals with Ds. Lastly, participants will perform a graded maximal
        treadmill exercise test to determine peak oxygen uptake (VO2peak) and to determine the
        submaximal exercise intensity for the second visit.
  
        The second visit will have participants walk on an intensity associated with 80% of their
        ventilatory threshold for six minutes while pulmonary oxygen uptake (using breath-by-breath
        gas exchange analysis), cardiac output (using beat-to-beat blood pressure measurement), and
        muscle oxygenation (using near-infrared spectroscopy (NIRS)) is measured. This bout of six
        minutes will be repeated four times, with 10 minutes rest in between. The four bouts will be
        used to average the three signals, which improves the calculation of kinetic parameters.
  
        Familiarization. Parents/care givers are involved in order to provide a supportive
        environment for participants and to enhance the parent/caregiver understanding of the
        research. Prior to study initiation, photographs and video clips of the laboratory and study
        equipment will be provided to help the participants become comfortable with the laboratory
        environment and equipment, and the informed consent information is sent to the participants
        and their parents/care-givers for their review. Familiarization for the participants with
        Down syndrome will be divided in two parts: they will practice and become accustomed with the
        treadmill and the equipment for the graded maximal exercise test (very start of the first
        visit), and they will practice and become accustomed with the procedures for the submaximal
        exercise protocol (start of the second visit).
  allocation: Non-Randomized
  intervention model: Parallel Assignment
  primary purpose: Screening
  masking: None (Open Label)
  measure: Oxygen uptake kinetics
  time frame: Through study completion, on average 4 hours
  description: The finite rate at which oxygen uptake (measured with breath-by-breath gas exchange analysis at the mouth) adapts to a (submaximal) increase in exercise intensity, primarily captured by time constant tau, which describes the time needed to reach 63% of the required, steady state oxygen uptake
  measure: Cardiac output kinetics
  time frame: Through study completion, on average 4 hours
  description: The finite rate at which cardiac output (calculated from beat-to-beat blood pressure waves) adapts to a (submaximal) increase in exercise intensity, primarily captured by time constant tau, which describes the time needed to reach 63% of the required, steady state cardiac output
  measure: Muscle deoxygenation kinetics
  time frame: Through study completion, on average 4 hours
  description: The finite rate at which muscle oxygen utilization (measured as the production of deoxyhemoglobin at the muscle) adapts to a (submaximal) increase in exercise intensity, primarily captured by time constant tau, which describes the time needed to reach 63% of the required, steady state muscle oxygen utilization
  measure: Steady-state cardiac output
  time frame: Through study completion, on average 4 hours
  description: Steady state cardiac output during standing rest and submaximal exercise (in L/min)
  measure: Absolute peak oxygen uptake
  time frame: Through study completion, on average 4 hours
  description: Peak oxygen uptake (VO2peak; expressed in L/min)
  measure: Relative peak oxygen uptake (corrected for total body mass)
  time frame: Through study completion, on average 4 hours
  description: Peak oxygen uptake (VO2peak; expressed in ml/kg/min)
  measure: Relative peak oxygen uptake (corrected for lean body mass)
  time frame: Through study completion, on average 4 hours
  description: Peak oxygen uptake (VO2peak; expressed in L=mL/kg lean body mass/min)
  measure: Ventilatory threshold (L/min)
  time frame: Through study completion, on average 4 hours
  description: The threshold where ventilation starts to increase at a faster rate than oxygen uptake during a graded maximal exercise test (expressed in L/min)
  measure: Ventilatory threshold (%VO2peak)
  time frame: Through study completion, on average 4 hours
  description: The threshold where ventilation starts to increase at a faster rate than oxygen uptake during a graded maximal exercise test (expressed as a percentage of VO2peak)
  measure: Stroke volume
  time frame: Through study completion, on average 4 hours
  description: Stroke volume (mL)
  measure: Heart rate
  time frame: Through study completion, on average 4 hours
  description: Heart rate (in bpm)
  measure: Oxygen uptake efficiency slope
  time frame: Through study completion, on average 4 hours
  description: The slope between oxygen uptake (L/min) and the common logarithm of minute ventilation (L/min) during a graded maximal exercise test
  measure: Ve/VCO2 slope
  time frame: Through study completion, on average 4 hours
  description: The slope between minute ventilation (Ve; L/min) and carbon dioxide production (VCO2; L/min) during a graded maximal exercise test
  measure: Lean body mass
  time frame: Through study completion, on average 4 hours
  description: Lean body mass determined with Dual Energy X-ray Absorptiometry (DXA) scan in kg
  arm group label: Down syndrome
  arm group type: Experimental
  description: Participants will complete a submaximal walking protocol on a motorized treadmill, which consists of 4 times 6 minutes of walking at a moderate intensity speed and incline while their breathing, cardiac output, and muscle oxygen use is measured, with 10 minutes rest in between each bout.
  arm group label: control without Down syndrome
  arm group type: Experimental
  description: This group of age- and sex-matched participants without Down syndrome will undergo the same testing as participants with Down syndrome
  intervention type: Other
  intervention name: Submaximal exercise protocol
  description: Participants will complete a submaximal walking protocol on a motorized treadmill, which consists of 4 times 6 minutes of walking at a moderate intensity speed and incline while their breathing, cardiac output, and muscle oxygen use is measured, with 10 minutes rest in between each bout.
  arm group label: Down syndrome
  arm group label: control without Down syndrome
  criteria: 
  gender: All
  minimum age: 18 Years
  maximum age: 35 Years
  healthy volunteers: Accepts Healthy Volunteers
  last name: Victor DY Beck, MS
  role: Principal Investigator
  affiliation: University of Nevada, Las Vegas
  last name: Victor DY Beck, MS
  phone: 702-895-3003
  email: victor.beck@unlv.edu
  last name: Thessa IM Hilgenkamp, PhD
  phone: 702-895-3003
  email: thessa.hilgenkamp@unlv.edu
  facility: 
  status: Recruiting
  contact: 
  country: United States
  responsible party type: Principal Investigator
  investigator affiliation: University of Nevada, Las Vegas
  investigator full name: Victor Beck
  investigator title: Graduate Research Assistant
  mesh term: Down Syndrome
  mesh term: Syndrome
  sharing ipd: No
  ipd description: De-identified IPD will be made available to other researchers upon request.