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DysgeusiagustinpropNCT01097915

Gustin Gene Polymorphism and 6-n-propylthiouracil (PROP) Taste

An observational study of Dysgeusia, run by University of Cagliari at 1 site in Italy.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
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Trial summary

The investigators evaluate the possible association of PROP taste with gustin gene polymorphism rs2274333 (A/G), salivary zinc ion concentration and BMI. In addition, it has also been evaluated PROP taste sensitivity by recording monophasic potentials from the tongue. Read more about this study

Who is it for?
Ages 20 to 30 yearsHealthy volunteers can take part
Conditions the study is for
Dysgeusia
How many people
170 participants
Where
1 siteItaly
Study dates
Oct 2009to Jun 2016
Phase
Observational
Are there results?
Yes, posted in the registrySummary in the doctors' view

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 20 to 30 years
  • All sexes
  • Healthy volunteers accepted
  • Adult

Study population: Seventy-five non-smoking volunteers (28 men and 47 women) were recruited for the study. Participants between 20-30 years were eligible for the study. Thresholds for the 4 basic tastes were evaluated in all subjects in order to rule out any gustatory impairment. The volunteers showed no variation of body weight > 5 kg over the last 3 mo. They were not following a prescribed diet or using medications that might interfere with taste perception; none had food allergies. They were assessed for cognitive eating behaviours using the Three-Factor Eating Questionnaire

Who may be able to join

  • no variation of body weight > 5 kg over the last 3 mo BMI within 20-25 Age between 20-30

Who cannot join

  • gustatory impairment following a prescribed diet or using medications that might interfere with taste perception food allergies smokers

Trial locations and contacts

1 site in 1 country.

Italy1 site
  • Sezione di Farmacologia Clinica del Dipartimento di Neuroscienze, San Giovanni di Dio Azienda Ospedaliero Universitaria di Cagliari

    Cagliari, Ca, 09124

Other trials in Italy

About this study

Official title: Sensitivity to 6-n-propylthiouracil (PROP) Association With Gustin (CA6) Gene Polymorphism, Salivary Zinc and BMI in Humans

The investigators evaluate the possible association of PROP taste with gustin gene polymorphism rs2274333 (A/G), salivary zinc ion concentration and BMI. In addition, it has also been evaluated PROP taste sensitivity by recording monophasic potentials from the tongue.

Read the detailed description

The investigators evaluate the possible association of PROP taste with gustin gene polymorphism rs2274333 (A/G), salivary zinc ion concentration and BMI.

Furthermore, we apply direct measures of the gustatory system activation following stimulation with PROP, obtained by electrophysiological recordings from the tongue of subjects classified for taster status, genotyped for the specific receptor gene (TAS2R38), and in which papilla density was determined.

Conditions
Dysgeusia
Keywords
PROP taste sensitivity, Gustin (CAVI) polymorphism, Salivary zinc, BMI, Electrophysiological recording from the tongue
Medical subject headings
Dysgeusia

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

Study groups in NCT01097915
Study groupRoleWhat they receive
PROP taste sensitivityPROP Sensitive and non sensitive individuals are defined as "Tasters" and "Non-tasters", respectively. Taster are further divided in "Super-taster" who perceived PROP as extremely bitter and "Medium tasters" who perceived PROP as moderately bitter.

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Association Between Gustin Gene Polymorphism and PROP Sensitivity

    We examine associations between PROP status and the polymorphism rs2274333 (A/G) of the gene that codify for the salivary protein, gustin/CA6, Which has been suggested as a trophic factor that promotes growth and development of taste buds by acting on taste bud stem cells.

    The intensity of taste perception evoked by PROP and NaCl solutions was estimated to evaluate PROP taster status and molecular analysis of the gustin gene polymorphism was performed in individuals classified by PROP status using PCR techniques.

    Measured: 7 months

Secondary outcomes (5)
  1. Association Between PROP Sensitivity and Saliva Zinc Ion Concentration

    Since the enzymatic function of gustin (CA6) depends upon the presence of Zn at its active site we measured the salivary zinc ion concentration in subjects classified as super-taster, medium taster and non-taster.The salivary Zn2+ concentration was measured with a QuantiChromTM zinc Assay kit (Gentaur, Brussels, Belgium) where the color intensity is directly proportional to the Zn2+ concentration in the sample.

    Measured: 7 months

  2. Association Between PROP Sensitivity and BMI

    Since individual ability to taste PROP may be correlated with BMI, we determined BMI (kg/m^2) in subjects classified as super-taster, medium taster and non-taster.Weight (kg) and height (m) were recorded for each subject.

    Measured: 7 months

  3. Electrophysiological Recordings From the Tongue for the Objective Evaluation of Individual Variations of 6-n-propylthiouracil (PROP) Sensitivity

    electrophysiological recordings from the tongue of 43 subjects classified for their taste sensitivity to 6-n- propyltiouracil (PROP) and genotyped for the specific receptor gene, TAS2R38. Density of fungiform papillae was also determined in each subject. The biopotentials were recorded by means of differential electrophysiological derivations between two silver electrodes, one in contact with the ventral surface of the tongue and one in perfect adhesion with the dorsal surface.

    Measured: 1 year

  4. Association Between PROP Sensitivity and Fungiform Papilla Density

    43 subjects were classified for their taste sensitivity to 6-n- propyltiouracil (PROP) and density of fungiform papillae was determined in each subject.

    Measured: 6 months

  5. Taste Perception of Sweet, Sour, Salty, Bitter and Umami and Changes Due to L-Arginine Supplementation, as a Functin of Genetic Ability to Taste PROP.

    Taste perception was assessed by testing the ability to recognize, and the responsiveness to, representative solutions of the five taste qualities, also when supplemented with L-Arg, in subjects classified as PROP-tasters.

    Measured: 8 months

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted2 Apr 2010 (estimated)
  2. Study startOct 2009
  3. Primary completionDec 2009
  4. Study completionJun 2016

Resources

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
Cohort
Time perspective
Prospective
Enrolment
170 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT01097915
Sponsor's protocol ID
UNICADBSITB-1
Acronym
gustinprop
Status last verified
Dec 2018
First submitted
1 Apr 2010
Last updated
21 Dec 2018
Data monitoring committee
No
Individual data sharing
Undecided: Data of this study are available from the principal investigator of this study upon request

Publications

  • Padiglia A, Zonza A, Atzori E, Chillotti C, Calo C, Tepper BJ, Barbarossa IT. Sensitivity to 6-n-propylthiouracil is associated with gustin (carbonic anhydrase VI) gene polymorphism, salivary zinc, and body mass index in humans. Am J Clin Nutr. 2010 Sep;92(3):539-45. doi: 10.3945/ajcn.2010.29418. Epub 2010 Jul 14.

    PubMed 20631203

Questions about this trial

What is this clinical trial studying?

An observational study of Dysgeusia, run by University of Cagliari at 1 site in Italy.

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 1 inclusion and 1 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: finished, as of the sponsor's last update on 21 Dec 2018. 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 Italy. 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?

Yes. Results are posted in the registry (first posted 21 Dec 2016). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Association Between Gustin Gene Polymorphism and PROP Sensitivity (time frame: 7 months). It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT01097915, which also lists 1 linked publication.

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 21 Dec 2018.

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