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Uric Acid Metabolism, Endothelial Function and Oxidative Stress in Vegans and Omnivores.

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ClinicalTrials.gov Identifier: NCT03849677
Recruitment Status : Recruiting
First Posted : February 21, 2019
Last Update Posted : March 13, 2019
Sponsor:
Collaborators:
Fonds National de la Recherche Scientifique
Fonds Erasme
Fonds pour la chirurgie cardiaque
Information provided by (Responsible Party):
Erasme University Hospital

Tracking Information
First Submitted Date February 6, 2019
First Posted Date February 21, 2019
Last Update Posted Date March 13, 2019
Estimated Study Start Date March 10, 2019
Estimated Primary Completion Date December 2019   (Final data collection date for primary outcome measure)
Current Primary Outcome Measures
 (submitted: February 19, 2019)
Measure of the perfusion of the microcirculation of the skin [ Time Frame: 2 hours ]
Endothelial function assessment will be performed through analyse of the perfusion of the microcirculation of the skin in the forearm will be assessed by means of a laser Doppler imager and iontophoresis of acetylcholine and sodium nipride. Heating-induced hyperemia will be assessed after iontophoresis of inhibitor of NO synthase and saline. Units are perfusion unit. Iontophoresis is a non-invasive tool which permits to infuse molecules in the first micrometers of the skin. The used molecules are vasodilative, saline or NO synthase inhibitor.
Original Primary Outcome Measures Same as current
Change History Complete list of historical versions of study NCT03849677 on ClinicalTrials.gov Archive Site
Current Secondary Outcome Measures
 (submitted: March 11, 2019)
  • Concentration of Uric acid [ Time Frame: 2 hours ]
    Uric acid (mg/dL or SI)
  • Concentration of xanthine oxidase and xanthine dehydrogenase in blood [ Time Frame: 2 hours ]
    western blot
  • Measure of hemoglobin [ Time Frame: 2 hours ]
    g/l
  • Measure of white blood cells, red blood cells and platelets [ Time Frame: 2 hours ]
    cells/µl of blood
  • Measure of urea, creatinine, bilirubin, albumine, prealbumin, LDL, HDL, lp(a), total cholesterol, triglyceride, apolipoprotein A and B [ Time Frame: 2 hours ]
    mg/dl
  • Measure of glycemia, vitamine and iron status (B3, B6, B12, C, D, E, B9, Zn, Cu, Selenium, iron, ferritin), c-reactive protein, homocystein [ Time Frame: 2 hours ]
    mg/dl
  • Measure of sodium, potassium, chlore, phosphor, calcium, magnesium, HbA1c, omega 3 et 6 [ Time Frame: 2 hours ]
    mmol/l
  • Measure of glomerular filtration rate [ Time Frame: 2 hours ]
    ml/min
  • Measure of gamma-glutamyltransferase, alkaline phosphatase, aspartate aminotransferase, alanine aminotransferase, lactate dehydrogenase, creatin phosphokinase, insulin, TSH [ Time Frame: 2 hours ]
    u/l
  • Measure of allantoin, homocitrulline/lysine, chloro-tyrosine/tyrosine, Il-8, myeloperoxidase [ Time Frame: 2 hours ]
    Mass spectrometry and Elisa Kits
  • Measure of renin, aldosterone, angiotensin 2, angiotensin converting enzyme [ Time Frame: 2 hours ]
  • Measure of main proteomes and metabolomes in cells incubated with sera from participants [ Time Frame: 2 hours ]
    Sera will be used for cell cultures. Theses cells will be lysed and used to analyse and compare the different proteomes / metabolomes according to the groups. We will be able to understand which protein groups are reduced or enhanced according to the diet.
  • Measure of blood pressure [ Time Frame: 2 hours ]
    Systolic and diastolic blood pressure
  • Measure of baroreflex sensitivity [ Time Frame: 2 hours ]
    finometer
  • Measure of heart rate [ Time Frame: 2 hours ]
    finometer
  • Measure of augmentation index [ Time Frame: 2 hours ]
    Assessment of the arterial stiffness
  • Measure of pulse wave velocity [ Time Frame: 2 hours ]
    Assessment of the arterial stiffness
  • Diet questionary [ Time Frame: 2 hours ]
    Diet History Questionnaire third version provides estimation of one year consumption of proteins, carbohydrates, lipids, micronutrient and vitamines
Original Secondary Outcome Measures
 (submitted: February 19, 2019)
  • Concentration of Uric acid [ Time Frame: 2 hours ]
    Uric acid (mg/dL or SI)
  • Concentration of xanthine oxidase and xanthine dehydrogenase in blood [ Time Frame: 2 hours ]
    western blot
  • Measure of hemoglobin [ Time Frame: 2 hours ]
    g/l
  • Measure of white blood cells, red blood cells and platelets [ Time Frame: 2 hours ]
    cells/µl of blood
  • Measure of urea, creatinine, bilirubine, albumine, prealbumine, LDL, HDL, lp(a), total cholesterol, triglycerid, apolipoprotein A and B [ Time Frame: 2 hours ]
    mg/dl
  • Measure of glycemia, vitamine and iron status (B3, B6, B12, C, D, E, B9, Zn, Cu, Selenium, iron, ferritin), c-reactive proteine, homocystein [ Time Frame: 2 hours ]
    mg/dl
  • Measure of sodium, potassium, chlore, phosphor, calcium, magnesium, HbA1c, omega 3 et 6 [ Time Frame: 2 hours ]
    mmol/l
  • Measure of glomerular filtration rate [ Time Frame: 2 hours ]
    ml/min
  • Measure of gamma-glutamyltransferase, alkalin phosphatase, aspartate aminotransferase, alanine aminotransferase, lactate dehydrogenase, creatin phosphokinase, insulin, TSH [ Time Frame: 2 hours ]
    u/l
  • Measure of allantoin, homocitrulline/lysine, chloro-tyrosine/tyrosine, Il-8, myeloperoxidase [ Time Frame: 2 hours ]
    Mass spectrometry and Elisa Kits
  • Measure of renin, aldosterone, angiotensin 2, angiotensin converting enzyme [ Time Frame: 2 hours ]
  • Measure of main proteomes and metabolomes in cells incubated with sera from participants [ Time Frame: 2 hours ]
    Sera will be used for cell cultures. Theses cells will be lysed and used to analyse and compare the different proteomes / metabolomes according to the groups. We will be able to understand which protein groups are reduced or enhanced according to the diet.
  • Measure of blood pressure [ Time Frame: 2 hours ]
    Systolic and diastolic blood pressure
  • Measure of baroreflex sensitivity [ Time Frame: 2 hours ]
    finometer
  • Measure of heart rate [ Time Frame: 2 hours ]
    finometer
  • Measure of augmentation index [ Time Frame: 2 hours ]
    Assessment of the arterial stiffness
  • Measure of pulse wave velocity [ Time Frame: 2 hours ]
    Assessment of the arterial stiffness
  • Diet questionary [ Time Frame: 2 hours ]
    Diet History Questionnaire third version provides estimation of one year consumption of preoteins, carbohydrates, lipids, micronutrient and vitamines
Current Other Pre-specified Outcome Measures Not Provided
Original Other Pre-specified Outcome Measures Not Provided
 
Descriptive Information
Brief Title Uric Acid Metabolism, Endothelial Function and Oxidative Stress in Vegans and Omnivores.
Official Title Differential Analysis of Uric Acid Metabolism, Endothelial Function, Oxidative Stress and Cardiovascular Parameters in Vegans and Omnivores.
Brief Summary

50 vegans and 50 omnivores will be recruited at the Erasme Hospital, Brussels.

Hypothesis

  • Relative induced-hyperuricemia by the vegan diet is not associated with impaired endothelial function if vitamin B12 and folic acid levels are normal.
  • Quantification of xanthine oxidoreductase (XOR) isoforms varies according to the diet. Omnivores present more xanthine oxidase (XO) than vegans in which the xanthine dehydrogenase (XD) isoform is more prevalent.
  • The vegan group has more favorable oxidant, metabolic and inflammatory profiles than the omnivore group.
Detailed Description

Non-meat eaters rise widely worldwide. This choice answers ideological, ecological or health concerns. Several vegetarian diets exist and the vegan diet is the most restricted one as it excludes all animal products, eggs and dairy.

Beside benefits on health and particularly on the cardiovascular system (blood pressure, weight, lipid profile), some authors described less favorable lipid and oxidative profiles and others described an impairment in endothelial function markers in 'vegans'. These effects were attributed to low vitamin B12 and folate levels and high homocystein levels. However, vitamin B12 supplementation improved these parameters. Epidemiological studies also showed that 'vegans' disclose higher uric acid levels than other vegetarians or omnivores. Uric acid acts as an antioxidant in the plasma but can be deleterious for vascular cells leading to endothelial dysfunction. The main enzyme involved in uric acid metabolism is xanthine oxidoreductase which exists under two interconvertible isoforms. Xanthine dehydrogenase is the main form and uses nicotinamide adenine dinucleotide (NAD+) as electron acceptor and does not produce reactive oxygen species (ROS). In contrast, the other isoform xanthine oxidase uses oxygen as an electron acceptor and produces reactive oxygen species (ROS). The investigators wish to test the hypothesis that it is not uric acid per se, but which isoform of xanthine oxidoreductase which alters endothelial function. This is why the investigators wish to determine if regular 'vegans' (with normal vitamin B12 and folate levels) disclose increased uric acid levels in the presence of a reduced inflammation, oxidative stress and improved endothelial function, as compared to matched 'omnivores'.

50 vegans and 50 omnivores will be recruited at the Erasme Hospital, Brussels.

Hypothesis

  • Relative induced-hyperuricemia by the vegan diet is not associated with impaired endothelial function if vitamin B12 and folic acid levels are normal.
  • Quantification of oxidoreductase (XOR) isoforms varies according to the diet. Omnivores present more xanthine oxidase (XO) than vegans in which the xanthine dehydrogenase (XD) isoform is more prevalent.
  • The vegan group has more favorable oxidant, metabolic and inflammatory profiles than the omnivore group.
Study Type Observational
Study Design Observational Model: Case-Control
Time Perspective: Prospective
Target Follow-Up Duration Not Provided
Biospecimen Not Provided
Sampling Method Non-Probability Sample
Study Population Participants will be recruited upon invitation on social network mainly.
Condition
  • Healthy
  • Diet Modification
Intervention Other: Endothelial function and inflammation
Analysis of endothelial function, oxidative stress
Study Groups/Cohorts
  • Omnivore
    Intervention: Other: Endothelial function and inflammation
  • Vegan
    Intervention: Other: Endothelial function and inflammation
Publications * Not Provided

*   Includes publications given by the data provider as well as publications identified by ClinicalTrials.gov Identifier (NCT Number) in Medline.
 
Recruitment Information
Recruitment Status Recruiting
Estimated Enrollment
 (submitted: February 19, 2019)
100
Original Estimated Enrollment Same as current
Estimated Study Completion Date June 2020
Estimated Primary Completion Date December 2019   (Final data collection date for primary outcome measure)
Eligibility Criteria

Inclusion Criteria:

  • Vegan or omnivore diet for at least one year (matched for age, gender, BMI, socio-economic status and weight)
  • Healthy

Exclusion Criteria:

  • Smoking
  • Chronic treatment
  • No allowed drugs taking
  • Excessive alcohol consumption
Sex/Gender
Sexes Eligible for Study: All
Ages 20 Years to 50 Years   (Adult)
Accepts Healthy Volunteers Yes
Contacts
Contact: Benjamin De Becker, MD 025555919 ext +32 benjamin.de.becker@erasme.ulb.ac.be
Listed Location Countries Belgium
Removed Location Countries  
 
Administrative Information
NCT Number NCT03849677
Other Study ID Numbers 34735921
Has Data Monitoring Committee No
U.S. FDA-regulated Product
Studies a U.S. FDA-regulated Drug Product: No
Studies a U.S. FDA-regulated Device Product: No
IPD Sharing Statement
Plan to Share IPD: No
Responsible Party Erasme University Hospital
Study Sponsor Erasme University Hospital
Collaborators
  • Fonds National de la Recherche Scientifique
  • Fonds Erasme
  • Fonds pour la chirurgie cardiaque
Investigators Not Provided
PRS Account Erasme University Hospital
Verification Date March 2019