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Trial record 86 of 401 for:    PYY

A Study of the Function of Hormones Present In Taste Buds

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT00233298
Recruitment Status : Completed
First Posted : October 5, 2005
Last Update Posted : April 5, 2018
Information provided by (Responsible Party):
National Institutes of Health Clinical Center (CC) ( National Institute on Aging (NIA) )

Brief Summary:
The purpose of this study is to find out whether the hormones in the taste buds are affected by tasting and eating food, and also whether these hormone levels are affected by an increase in body weight or type 2 diabetes.

Condition or disease
Diabetes Obesity Pre-Diabetes Metabolic Syndrome

Detailed Description:

Cephalic phase of insulin secretion is regulated by autonomic and endocrine responses to food-related sensory stimulation such as sight, smell, and taste. Human taste perception comprises of at least five distinct qualities: bitterness, saltiness, sourness, sweetness, and umami, the sensation elicited by glutamate, commonly found in protein (meat, fish, and legumes) and flavor enhancer such as monosodium glutamate (MSG).

Both the sweet and umami taste stimuli had been shown to illicit cephalic-phase insulin release in rats. Oral sensory stimulation in human with modified sham feeding (MSF where food is smelled, chewed, but not swallowed) had been shown to enhance insulin release during the cephalic phase, lower postprandial glucose level, and improve glucose tolerance in healthy subjects. The loss of pre-absorptive insulin response has been shown to impair glucose tolerance. Furthermore, patients with type 2 diabetes and their first degree relatives had been shown to have impairment of sweet taste.

Recently, glucagon-like peptide-1 (GLP-1) and peptide YY (PYY) have been found in the taste cells located in the taste buds of mice (unpublished data). These new findings raise several interesting questions of whether strict tasting of food without ingestion may stimulate secretion of GLP-1 and PYY from the taste cells, whether their secretion is involved in the afferent input of the cranial nerves, and whether this secretion is impaired in obesity and in patients with pre-diabetes or type 2 diabetes. We also want to investigate whether different tastants, such as sweet versus umami, and different food contents such as percent fat versus carbohydrate compositions, would elicit different hormonal responses.

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Study Type : Observational
Actual Enrollment : 225 participants
Time Perspective: Prospective
Official Title: A Study of the Function of Hormones Present In Taste Buds
Study Start Date : May 26, 2005
Study Completion Date : January 2, 2015

Resource links provided by the National Library of Medicine

Primary Outcome Measures :
  1. Whether CLP-1 and PYY are involved in the cephalic phase response during feeding [ Time Frame: 12 months ]
  2. Differences in response among healthy, healthy obese, pre-diabetic or 3 diabetes [ Time Frame: 12 months ]

Information from the National Library of Medicine

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Ages Eligible for Study:   12 Years to 50 Years   (Child, Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes

    1. Males or females age 20 to 50
    2. body weight > 50 kg (110 pounds)
    3. Group A

      1. BMI < 25 kg/m(2)
      2. healthy
    4. Group B

      1. BMI greater than or equal to 30 kg/ m(2)
      2. healthy
    5. Group C

      1. Pre-diabetes
      2. Pre-diabetes is defined as having either impaired fasting glucose (IFG) (fasting plasma glucose (FPG) greater than or equal to100 mg/dl but < 126 mg/dl) and/or impaired glucose tolerance (IGT) (2-hour OGTT glucose greater than or equal to140 mg/dl but < 200 mg/dl).
      3. BMI greater than or equal to 30 kg/m(2)
    6. Group D

      1. Type 2 diabetes (on diet or oral agents management only except for thiazolidinediones)
      2. Type 2 diabetes is defined as FPG 126 mg/dl and/or 2-hour OGTT glucose


      3. BMI greater than or equal to 30 kg/m(2)
    7. Screening laboratory evaluations with no significant abnormal results:

      1. comprehensive metabolic panel
      2. complete blood count with differential and platelets
      3. fasting plasma glucose < 100 mg/dl for healthy groups only (Group A and B)
      4. 2-hour 75-gram OGTT glucose < 140 mg/dl for healthy groups only (Group A and B)
      5. Negative pregnancy test for women of child-bearing potential
    8. Able to complete an informed consent


  1. Pregnancy (pregnancy has been shown to be associated with decrease in insulin sensitivity
  2. Group A and B subjects cannot have FPG greater than or equal to 100 mg/dl or 2-hr OGTT greater than or equal to 140 mg/dl
  3. Group D subjects cannot have FPG > 240 mg/dl during the screening visit
  4. Group D subjects cannot have their morning fasting finger-stick glucose > 240 mg/dl during the 5 days (3 days for glucophage) prior to the visit when their oral hypoglycemic agent(s) are discontinued
  5. Subjects with type 2 diabetes on insulin therapy
  6. Hematocrit < 36% for women and < 38% for men
  7. Peanut allergy
  8. Presence of other medical conditions that could affect glucose homeostasis
  9. Use of medications known to impair glucose homeostasis (i.e., amiloride shown to inhibit certain taste responses in hamsters)
  10. History of liver or renal disease
  11. History of gastrointestinal or endocrine disorders except for treated hypo- or hyperthyroidism
  12. Long-term glucocorticoid use (over one month), or other immunosuppressive agents within the past 5 years

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT00233298

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United States, Maryland
National Institute of Aging, Clinical Research Unit
Baltimore, Maryland, United States, 21224
Sponsors and Collaborators
National Institute on Aging (NIA)
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Principal Investigator: Josephine M Egan, M.D. National Institute on Aging (NIA)

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Responsible Party: National Institute on Aging (NIA) Identifier: NCT00233298     History of Changes
Other Study ID Numbers: 999905254
First Posted: October 5, 2005    Key Record Dates
Last Update Posted: April 5, 2018
Last Verified: January 2, 2015

Keywords provided by National Institutes of Health Clinical Center (CC) ( National Institute on Aging (NIA) ):
Blood Sugar
Blood Glucose Level
Insulin Sensitivity
Type 2 Diabetes

Additional relevant MeSH terms:
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Diabetes Mellitus
Metabolic Syndrome
Prediabetic State
Glucose Intolerance
Glucose Metabolism Disorders
Metabolic Diseases
Endocrine System Diseases
Insulin Resistance
Hormones, Hormone Substitutes, and Hormone Antagonists
Physiological Effects of Drugs