A Study of the Function of Hormones Present In Taste Buds

This study has been completed.
Sponsor:
Information provided by (Responsible Party):
National Institutes of Health Clinical Center (CC) ( National Institute on Aging (NIA) )
ClinicalTrials.gov Identifier:
NCT00233298
First received: October 3, 2005
Last updated: March 14, 2014
Last verified: October 2012
  Purpose

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
Diabetes
Obesity
Pre-Diabetes
Metabolic Syndrome

Study Type: Observational
Study Design: Time Perspective: Prospective
Official Title: A Study of the Function of Hormones Present In Taste Buds

Resource links provided by NLM:


Further study details as provided by National Institutes of Health Clinical Center (CC):

Primary Outcome Measures:
  • Whether CLP-1 and PYY are involved in the cephalic phase response during feeding [ Time Frame: 12 months ] [ Designated as safety issue: No ]
  • Differences in response among healthy, healthy obese, pre-diabetic or 3 diabetes [ Time Frame: 12 months ] [ Designated as safety issue: No ]

Estimated Enrollment: 300
Study Start Date: May 2005
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peptide-1 (GLP-1) and peptide YY (PYY) have been found in the taste cells located in the taste buds of mice (unpublished data).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.

  Eligibility

Ages Eligible for Study:   12 Years to 50 Years
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   Yes
Criteria
  • INCLUSION CRITERIA:

    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

        200

      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

EXCLUSION CRITERIA:

  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
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its ClinicalTrials.gov identifier: NCT00233298

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

Publications:
Responsible Party: National Institutes of Health Clinical Center (CC) ( National Institute on Aging (NIA) )
ClinicalTrials.gov Identifier: NCT00233298     History of Changes
Other Study ID Numbers: 999905254, 05-AG-N254
Study First Received: October 3, 2005
Last Updated: March 14, 2014
Health Authority: United States: Federal Government

Keywords provided by National Institutes of Health Clinical Center (CC):
Hypoglycemia
Blood Sugar
Blood Glucose Level
Insulin Sensitivity
Metabolism
Type 2 Diabetes
Healthy

Additional relevant MeSH terms:
Diabetes Mellitus
Obesity
Glucose Intolerance
Prediabetic State
Metabolic Syndrome X
Glucose Metabolism Disorders
Metabolic Diseases
Endocrine System Diseases
Overnutrition
Nutrition Disorders
Overweight
Body Weight
Signs and Symptoms
Hyperglycemia
Insulin Resistance
Hyperinsulinism
Hormones
Hormones, Hormone Substitutes, and Hormone Antagonists
Physiological Effects of Drugs
Pharmacologic Actions

ClinicalTrials.gov processed this record on July 22, 2014