<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/NCT02218112</url>
  </required_header>
  <id_info>
    <org_study_id>SNF_ 32003B_149903</org_study_id>
    <nct_id>NCT02218112</nct_id>
  </id_info>
  <brief_title>Impact of Weight Loss After a Bypass Surgery on Renal Hemodynamic Under Stress Conditions</brief_title>
  <acronym>OBBYSS</acronym>
  <official_title>Effect of Weight Loss Induced by a Bypass Surgery on Renal Salt Excretion, Renal Hemodynamic and on Neurohormonal Responses During an Induced Orthostatic Stress in Obese Patients</official_title>
  <sponsors>
    <lead_sponsor>
      <agency>Centre Hospitalier Universitaire Vaudois</agency>
      <agency_class>Other</agency_class>
    </lead_sponsor>
  </sponsors>
  <source>Centre Hospitalier Universitaire Vaudois</source>
  <oversight_info>
    <has_dmc>No</has_dmc>
  </oversight_info>
  <brief_summary>
    <textblock>
      The sympathetic nervous (SNS) and the renin angiotensin aldosterone system (RAS) have a&#xD;
      direct impact on renal hemodynamic, hormonal secretion and vasoactive peptide. Many&#xD;
      mechanisms including the SNS, RAS and renal sodium handling could explain the pathogenesis of&#xD;
      hypertension in obese patients. Lifestyle changes and bariatric surgery induce weight loss,&#xD;
      which is associated with blood pressure lowering in obese patients. A diminution in the renal&#xD;
      sympathetic stimulation and RAS activation could explain this effect.&#xD;
&#xD;
      The AIM of this study is to show that weight loss induced by bypass surgery in obese patients&#xD;
      affects renal salt excretion under &quot; low body negative pressure (LBNP)&quot; conditions .&#xD;
&#xD;
      Secondary objectives are to investigate the impact of weight loss on renal hemodynamic&#xD;
      (glomerular filtration rate (GFR), renal plasma flow) and neurohormonal responses under &quot; low&#xD;
      body negative pressure conditions &quot;. We will also analyse renal blood oxygenation with Blood&#xD;
      Oxygenation dependant IRM (BOLD-IRM) technique before and after weight loss.&#xD;
&#xD;
      The population of this study will consist in two groups including 36 patients. The first one&#xD;
      will include 24 obese patients that are going to undergo a bariatric surgery. The second one&#xD;
      will include 12 obese patients without any weight loss associated surgery.&#xD;
&#xD;
      Both group will undergo 3 investigation days. Each patient will have to undergo a screening&#xD;
      visit that will provide dietary advice to ensure a standardized salt intake (120-180&#xD;
      mmol/day) for the duration of the study. The first investigation will define baseline, the&#xD;
      second and third day of investigation will take place after 3 month and 12 month after&#xD;
      bariatric surgery for surgical patients or after baseline for patients without surgery. One&#xD;
      to two weeks before phase 1 and 3 patients will perform a BOLD-MRI. The surgery group will&#xD;
      undergo bariatric surgery between the first investigation phase (baseline) and the second. An&#xD;
      ambulatory blood pressure and 24-hour urine collection will precede each investigation day.&#xD;
      An investigation day consists in renal hemodynamics, neurohormonal and natriuretic response&#xD;
      measurements before, during and after 60 min of LBNP at -30mbar . The duration of the study&#xD;
      per subject is going to take 12 months.&#xD;
    </textblock>
  </brief_summary>
  <overall_status>Completed</overall_status>
  <start_date type="Actual">June 2014</start_date>
  <completion_date type="Actual">July 31, 2017</completion_date>
  <primary_completion_date type="Actual">July 31, 2017</primary_completion_date>
  <study_type>Observational [Patient Registry]</study_type>
  <has_expanded_access>No</has_expanded_access>
  <study_design_info>
    <observational_model>Cohort</observational_model>
    <time_perspective>Prospective</time_perspective>
  </study_design_info>
  <target_duration>1 Year</target_duration>
  <primary_outcome>
    <measure>Change in sodium excretion</measure>
    <time_frame>up to one year</time_frame>
    <description>Change in sodium excretion during LBNP conditions</description>
  </primary_outcome>
  <secondary_outcome>
    <measure>Blood pressure, renal hemodynamic and neurohormonal response</measure>
    <time_frame>up to one year</time_frame>
    <description>24 hour blood pressure measurement&#xD;
Inulin clearance for GFR measurement&#xD;
Renal plasma flow measured with p-aminohippuric acid (PAH) administration&#xD;
Renin plasmatic activity&#xD;
Aldosterone (plasma)&#xD;
Leptin (plasma)&#xD;
Adiponectin (plasma)&#xD;
Plasmatic and urinary electrolytes&#xD;
Plasmatic and urinary lithium</description>
  </secondary_outcome>
  <number_of_groups>2</number_of_groups>
  <enrollment type="Actual">36</enrollment>
  <condition>Obesity</condition>
  <condition>Bariatric Surgery</condition>
  <condition>Blood Pressure</condition>
  <arm_group>
    <arm_group_label>OB - Bariatric surgery (gastric bypass)</arm_group_label>
    <description>Obese patients who will undergo a bariatric surgery (gastric bypass)</description>
  </arm_group>
  <arm_group>
    <arm_group_label>OB- Control group</arm_group_label>
    <description>Obese patients who will not undergo surgery - Control group</description>
  </arm_group>
  <intervention>
    <intervention_type>Procedure</intervention_type>
    <intervention_name>bariatric surgery (gastric bypass)</intervention_name>
    <arm_group_label>OB - Bariatric surgery (gastric bypass)</arm_group_label>
  </intervention>
  <eligibility>
    <study_pop>
      <textblock>
        Patient will briefly be informed about the study during their follow-up at the obesity&#xD;
        consultation (Medical Universitary Polyclinic) and the they will be recruited at the&#xD;
        Nephrology center in CHUV (Lausanne).&#xD;
      </textblock>
    </study_pop>
    <sampling_method>Probability Sample</sampling_method>
    <criteria>
      <textblock>
        Inclusion Criteria:&#xD;
&#xD;
          -  BMI &gt;35 Kg/m2&#xD;
&#xD;
          -  Understanding and signing the informed consent&#xD;
&#xD;
          -  Estimated glomerular filtration rate &gt;60 ml/min/1.73 m2&#xD;
&#xD;
        Exclusion Criteria:&#xD;
&#xD;
          -  Acute disease&#xD;
&#xD;
          -  Asthma or history of asthma&#xD;
&#xD;
          -  Patient participating in another clinical trial 30 days before the beginning of the&#xD;
             study&#xD;
&#xD;
          -  Blood donation (450ml) 2 months before the beginning of the study&#xD;
&#xD;
          -  Chronic medication which influence renal function (NSAIDS, Others)&#xD;
&#xD;
          -  Allergy&#xD;
&#xD;
          -  Documented renal arterial stenosis&#xD;
&#xD;
          -  History of symptomatic orthostatic hypotension&#xD;
&#xD;
          -  Kidney transplantation&#xD;
&#xD;
          -  Kidney malformation / polycystic kidney disease&#xD;
&#xD;
          -  Impaired judgement&#xD;
&#xD;
          -  Liver failure with ascitis&#xD;
&#xD;
          -  Hip circumference at the upper anterior iliac spine &gt; 130cm&#xD;
&#xD;
          -  Waist circumference &gt;180cm and weighing &gt; 220kg&#xD;
&#xD;
          -  Contraindication/Allergy to furosemide, PAH or Inulin&#xD;
&#xD;
          -  Contraindication to MRI if the patient is going to undergo BOLD-MRI&#xD;
&#xD;
          -  Postprandial glycemia &gt; 11.0 mmol/L in diabetic patients&#xD;
&#xD;
          -  Blood pressure &gt; 180/110 assessed by 24 hour blood pressure measurement&#xD;
      </textblock>
    </criteria>
    <gender>All</gender>
    <minimum_age>18 Years</minimum_age>
    <maximum_age>65 Years</maximum_age>
    <healthy_volunteers>No</healthy_volunteers>
  </eligibility>
  <location>
    <facility>
      <name>Centre Hospitalier Universitaire Vaudois</name>
      <address>
        <city>Lausanne</city>
        <state>Vaud</state>
        <zip>1004</zip>
        <country>Switzerland</country>
      </address>
    </facility>
  </location>
  <location_countries>
    <country>Switzerland</country>
  </location_countries>
  <verification_date>March 2018</verification_date>
  <study_first_submitted>August 14, 2014</study_first_submitted>
  <study_first_submitted_qc>August 14, 2014</study_first_submitted_qc>
  <study_first_posted type="Estimate">August 15, 2014</study_first_posted>
  <last_update_submitted>March 15, 2018</last_update_submitted>
  <last_update_submitted_qc>March 15, 2018</last_update_submitted_qc>
  <last_update_posted type="Actual">March 16, 2018</last_update_posted>
  <responsible_party>
    <responsible_party_type>Principal Investigator</responsible_party_type>
    <investigator_affiliation>Centre Hospitalier Universitaire Vaudois</investigator_affiliation>
    <investigator_full_name>PD Dr. Grégoire Wuerzner</investigator_full_name>
    <investigator_title>MD</investigator_title>
  </responsible_party>
  <keyword>Blood pressure</keyword>
  <keyword>Obesity</keyword>
  <keyword>Glomerular filtration rate</keyword>
  <keyword>Renal Sodium handling</keyword>
  <condition_browse>
    <!-- CAUTION:  The following MeSH terms are assigned with an imperfect algorithm            -->
    <mesh_term>Weight Loss</mesh_term>
  </condition_browse>
  <!-- Results have not yet been posted for this study                                          -->
</clinical_study>


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/NCT02218112
org study id: SNF_ 32003B_149903
nct id: NCT02218112
lead sponsor: 
has dmc: No
The sympathetic nervous (SNS) and the renin angiotensin aldosterone system (RAS) have a
      direct impact on renal hemodynamic, hormonal secretion and vasoactive peptide. Many
      mechanisms including the SNS, RAS and renal sodium handling could explain the pathogenesis of
      hypertension in obese patients. Lifestyle changes and bariatric surgery induce weight loss,
      which is associated with blood pressure lowering in obese patients. A diminution in the renal
      sympathetic stimulation and RAS activation could explain this effect.

      The AIM of this study is to show that weight loss induced by bypass surgery in obese patients
      affects renal salt excretion under " low body negative pressure (LBNP)" conditions .

      Secondary objectives are to investigate the impact of weight loss on renal hemodynamic
      (glomerular filtration rate (GFR), renal plasma flow) and neurohormonal responses under " low
      body negative pressure conditions ". We will also analyse renal blood oxygenation with Blood
      Oxygenation dependant IRM (BOLD-IRM) technique before and after weight loss.

      The population of this study will consist in two groups including 36 patients. The first one
      will include 24 obese patients that are going to undergo a bariatric surgery. The second one
      will include 12 obese patients without any weight loss associated surgery.

      Both group will undergo 3 investigation days. Each patient will have to undergo a screening
      visit that will provide dietary advice to ensure a standardized salt intake (120-180
      mmol/day) for the duration of the study. The first investigation will define baseline, the
      second and third day of investigation will take place after 3 month and 12 month after
      bariatric surgery for surgical patients or after baseline for patients without surgery. One
      to two weeks before phase 1 and 3 patients will perform a BOLD-MRI. The surgery group will
      undergo bariatric surgery between the first investigation phase (baseline) and the second. An
      ambulatory blood pressure and 24-hour urine collection will precede each investigation day.
      An investigation day consists in renal hemodynamics, neurohormonal and natriuretic response
      measurements before, during and after 60 min of LBNP at -30mbar . The duration of the study
      per subject is going to take 12 months.
observational model: Cohort
time perspective: Prospective
measure: Change in sodium excretion
time frame: up to one year
description: Change in sodium excretion during LBNP conditions
measure: Blood pressure, renal hemodynamic and neurohormonal response
time frame: up to one year
description: 24 hour blood pressure measurement
Inulin clearance for GFR measurement
Renal plasma flow measured with p-aminohippuric acid (PAH) administration
Renin plasmatic activity
Aldosterone (plasma)
Leptin (plasma)
Adiponectin (plasma)
Plasmatic and urinary electrolytes
Plasmatic and urinary lithium
arm group label: OB - Bariatric surgery (gastric bypass)
description: Obese patients who will undergo a bariatric surgery (gastric bypass)
arm group label: OB- Control group
description: Obese patients who will not undergo surgery - Control group
intervention type: Procedure
intervention name: bariatric surgery (gastric bypass)
arm group label: OB - Bariatric surgery (gastric bypass)
study pop: 
sampling method: Probability Sample
criteria: 
gender: All
minimum age: 18 Years
maximum age: 65 Years
healthy volunteers: No
facility: 
country: Switzerland
responsible party type: Principal Investigator
investigator affiliation: Centre Hospitalier Universitaire Vaudois
investigator full name: PD Dr. Grégoire Wuerzner
investigator title: MD
mesh term: Weight Loss