Dysgeusia
Conditions
Keywords
PROP taste sensitivity, Gustin (CAVI) polymorphism, Salivary zinc, BMI, Electrophysiological recording from the tongue
Brief 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.
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.
Interventions
None listed
Sponsors
University of Cagliari
Study design
Observational model
COHORT
Time perspective
PROSPECTIVE
Eligibility
Sex/Gender
ALL
Age
20 Years to 30 Years
Healthy volunteers
Yes
Inclusion criteria
* no variation of body weight \> 5 kg over the last 3 mo BMI within 20-25 Age between 20-30
Exclusion criteria
* gustatory impairment following a prescribed diet or using medications that might interfere with taste perception food allergies smokers
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Association Between Gustin Gene Polymorphism and PROP Sensitivity | 7 months | 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. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Association Between PROP Sensitivity and Saliva Zinc Ion Concentration | 7 months | 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. |
| Association Between PROP Sensitivity and BMI | 7 months | 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. |
| Electrophysiological Recordings From the Tongue for the Objective Evaluation of Individual Variations of 6-n-propylthiouracil (PROP) Sensitivity | 1 year | 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. |
| Association Between PROP Sensitivity and Fungiform Papilla Density | 6 months | 43 subjects were classified for their taste sensitivity to 6-n- propyltiouracil (PROP) and density of fungiform papillae was determined in each subject. |
| 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. | 8 months | 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. |
Countries
Italy
Participant flow
Participants by arm
| Arm | Count |
|---|---|
| Super Tasters Subjects highly sensitive to PROP | 50 |
| Medium Tasters Subjects sensitive to PROP | 70 |
| Non Tasters Subjects no sensitive to PROP | 50 |
| Total | 170 |
Baseline characteristics
| Characteristic | Super Tasters | Medium Tasters | Non Tasters | Total |
|---|---|---|---|---|
| Age, Categorical <=18 years | 0 Participants | 0 Participants | 0 Participants | 0 Participants |
| Age, Categorical >=65 years | 0 Participants | 0 Participants | 0 Participants | 0 Participants |
| Age, Categorical Between 18 and 65 years | 50 Participants | 70 Participants | 50 Participants | 170 Participants |
| Age, Continuous | 25 years STANDARD_DEVIATION 7 | 25 years STANDARD_DEVIATION 8 | 25 years STANDARD_DEVIATION 6 | 25 years STANDARD_DEVIATION 7 |
| healthy volunteers | 50 participants | 70 participants | 50 participants | 170 participants |
| Race (NIH/OMB) American Indian or Alaska Native | 0 Participants | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Asian | 0 Participants | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Black or African American | 0 Participants | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) More than one race | 0 Participants | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Native Hawaiian or Other Pacific Islander | 0 Participants | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Unknown or Not Reported | 0 Participants | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) White | 50 Participants | 70 Participants | 50 Participants | 170 Participants |
| Region of Enrollment Italy | 50 participants | 70 participants | 50 participants | 170 participants |
| Sex: Female, Male Female | 35 Participants | 40 Participants | 34 Participants | 109 Participants |
| Sex: Female, Male Male | 15 Participants | 30 Participants | 16 Participants | 61 Participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk | EG002 affected / at risk |
|---|---|---|---|
| deaths Total, all-cause mortality | — / — | — / — | — / — |
| other Total, other adverse events | 0 / 27 | 0 / 28 | 0 / 20 |
| serious Total, serious adverse events | 0 / 27 | 0 / 28 | 0 / 20 |
Outcome results
Primary
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.
Time frame: 7 months
| Arm | Measure | Group | Value (NUMBER) |
|---|---|---|---|
| Super Tasters | Association Between Gustin Gene Polymorphism and PROP Sensitivity | Allele A | 92.59 percentage of participants |
| Super Tasters | Association Between Gustin Gene Polymorphism and PROP Sensitivity | Genotype GG | 0 percentage of participants |
| Super Tasters | Association Between Gustin Gene Polymorphism and PROP Sensitivity | Genotype AA | 85.19 percentage of participants |
| Super Tasters | Association Between Gustin Gene Polymorphism and PROP Sensitivity | Genotype AG | 14.81 percentage of participants |
| Super Tasters | Association Between Gustin Gene Polymorphism and PROP Sensitivity | Allele G | 7.40 percentage of participants |
| Medium Tasters | Association Between Gustin Gene Polymorphism and PROP Sensitivity | Genotype GG | 14.29 percentage of participants |
| Medium Tasters | Association Between Gustin Gene Polymorphism and PROP Sensitivity | Genotype AA | 50.99 percentage of participants |
| Medium Tasters | Association Between Gustin Gene Polymorphism and PROP Sensitivity | Genotype AG | 35.71 percentage of participants |
| Medium Tasters | Association Between Gustin Gene Polymorphism and PROP Sensitivity | Allele A | 67.86 percentage of participants |
| Medium Tasters | Association Between Gustin Gene Polymorphism and PROP Sensitivity | Allele G | 32.14 percentage of participants |
| Non Tasters | Association Between Gustin Gene Polymorphism and PROP Sensitivity | Allele G | 65 percentage of participants |
| Non Tasters | Association Between Gustin Gene Polymorphism and PROP Sensitivity | Allele A | 35 percentage of participants |
| Non Tasters | Association Between Gustin Gene Polymorphism and PROP Sensitivity | Genotype AA | 25.00 percentage of participants |
| Non Tasters | Association Between Gustin Gene Polymorphism and PROP Sensitivity | Genotype GG | 55 percentage of participants |
| Non Tasters | Association Between Gustin Gene Polymorphism and PROP Sensitivity | Genotype AG | 20 percentage of participants |
p-value: <0.01Fisher Exact
Secondary
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.
Time frame: 7 months
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Super Tasters | Association Between PROP Sensitivity and BMI | 20.3 Kg/m^2 | Standard Error 0.48 |
| Medium Tasters | Association Between PROP Sensitivity and BMI | 20.76 Kg/m^2 | Standard Error 0.58 |
| Non Tasters | Association Between PROP Sensitivity and BMI | 22.58 Kg/m^2 | Standard Error 0.84 |
p-value: <0.048ANCOVA
Secondary
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.
Time frame: 6 months
Population: Relationship between density of fungiform papillae and PROP taster status.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Super Tasters | Association Between PROP Sensitivity and Fungiform Papilla Density | 51.66 No./cm2 | Standard Error 5.25 |
| Medium Tasters | Association Between PROP Sensitivity and Fungiform Papilla Density | 33.49 No./cm2 | Standard Error 5.26 |
| Non Tasters | Association Between PROP Sensitivity and Fungiform Papilla Density | 18.53 No./cm2 | Standard Error 7.023 |
p-value: <0.00001ANOVA
Secondary
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.
Time frame: 7 months
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Super Tasters | Association Between PROP Sensitivity and Saliva Zinc Ion Concentration | 57.3 microg/dl | Standard Error 13 |
| Medium Tasters | Association Between PROP Sensitivity and Saliva Zinc Ion Concentration | 89.5 microg/dl | Standard Error 17.2 |
| Non Tasters | Association Between PROP Sensitivity and Saliva Zinc Ion Concentration | 149.64 microg/dl | Standard Error 26.4 |
p-value: <0.004ANOVA
Secondary
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.
Time frame: 1 year
Population: Relationship between depolarization amplitude of signals and PROP taster status.
| Arm | Measure | Value (MEAN) |
|---|---|---|
| Super Tasters | Electrophysiological Recordings From the Tongue for the Objective Evaluation of Individual Variations of 6-n-propylthiouracil (PROP) Sensitivity | 97,08867 mV |
| Medium Tasters | Electrophysiological Recordings From the Tongue for the Objective Evaluation of Individual Variations of 6-n-propylthiouracil (PROP) Sensitivity | 75,42000 mV |
| Non Tasters | Electrophysiological Recordings From the Tongue for the Objective Evaluation of Individual Variations of 6-n-propylthiouracil (PROP) Sensitivity | 48,48231 mV |
p-value: <0.00001ANOVA
Secondary
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.
Time frame: 8 months
| Arm | Measure | Group | Category | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|---|---|
| Super Tasters | 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. | NaCl | Correct identification | 52 Participants |
| Super Tasters | 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. | Citric Acid | Incorrect teste response | 10 Participants |
| Super Tasters | 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. | sucrose | Incorrect teste response | 6 Participants |
| Super Tasters | 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. | caffeine | Undet Threshold | 6 Participants |
| Super Tasters | 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. | NaCl | Incorrect teste response | 11 Participants |
| Super Tasters | 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. | caffeine | Correct identification | 56 Participants |
| Super Tasters | 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. | sucrose | Correct identification | 40 Participants |
| Super Tasters | 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. | caffeine | Incorrect teste response | 2 Participants |
| Super Tasters | 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. | Citric Acid | Undet Threshold | 5 Participants |
| Super Tasters | 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. | MSG | Undet Threshold | 7 Participants |
| Super Tasters | 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. | sucrose | Undet Threshold | 18 Participants |
| Super Tasters | 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. | MSG | Correct identification | 26 Participants |
| Super Tasters | 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. | Citric Acid | Correct identification | 49 Participants |
| Super Tasters | 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. | MSG | Incorrect teste response | 31 Participants |
| Super Tasters | 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. | NaCl | Undet Threshold | 1 Participants |
| Medium Tasters | 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. | MSG | Incorrect teste response | 31 Participants |
| Medium Tasters | 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. | sucrose | Undet Threshold | 2 Participants |
| Medium Tasters | 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. | sucrose | Correct identification | 20 Participants |
| Medium Tasters | 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. | sucrose | Incorrect teste response | 42 Participants |
| Medium Tasters | 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. | NaCl | Undet Threshold | 1 Participants |
| Medium Tasters | 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. | NaCl | Correct identification | 41 Participants |
| Medium Tasters | 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. | NaCl | Incorrect teste response | 22 Participants |
| Medium Tasters | 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. | Citric Acid | Undet Threshold | 4 Participants |
| Medium Tasters | 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. | Citric Acid | Correct identification | 47 Participants |
| Medium Tasters | 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. | Citric Acid | Incorrect teste response | 13 Participants |
| Medium Tasters | 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. | caffeine | Undet Threshold | 6 Participants |
| Medium Tasters | 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. | caffeine | Correct identification | 56 Participants |
| Medium Tasters | 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. | caffeine | Incorrect teste response | 2 Participants |
| Medium Tasters | 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. | MSG | Undet Threshold | 0 Participants |
| Medium Tasters | 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. | MSG | Correct identification | 33 Participants |
p-value: <0.00001Chi-squared