Clinical trial NCT01128400: Fat Perception in Humans (09-0873)
Official title: Inhibition of Lipolysis in Oral Cavity and Fat Perception in Humans
Study type: OBSERVATIONAL
Overall status: COMPLETED
Conditions: Obesity
Keywords: obesity
orlistat
taste perception
Lead sponsor: Washington University School of Medicine
Sponsor class: OTHER
Collaborators: name: GlaxoSmithKline
First posted: 2010-05-21
Enrollment: 40
Sex: ALL
Minimum age (years): 21
Maximum age (years): 50
Standard ages: ADULT
Accepts healthy volunteers: yes
Observational model: CASE_CONTROL
Time perspective: CROSS_SECTIONAL
Sampling method: NON_PROBABILITY_SAMPLE
Study population: A total of 40 obese subjects will participate in this study. Subjects will be men and women and will include all races and ethnic groups. The two groups (carriers and non-will be matched as closely as possible in age, sex, body mass index (kg/m²) and race distributions.

Brief summary: There are many substances naturally present in the mouth that may help us taste fat in food. Two of these substances (lipases and CD36) will be examined in this study.

The presence of fat in food increases food tastiness, therefore people often over-eat high-fat foods and gain weight. The purpose of this study is to determine if blocking lipases and some genetic variations in the CD36 gene will make fatty food less tasty so that people eat less. Our hypothesis is that Orlistat and a particular gene will increase one's ability to detect fat.

Detailed description: 1. Determine the effect of lipolysis inhibition in oral cavity on orosensory detection of fat in humans.

   Hypothesis: Orally applied Orlistat will increase detection thresholds of TAGs but not FFA in humans.

   To test this hypothesis we will measure triolein (a TAG) and oleic acid (a FFA) taste detection thresholds with a three-alternative forced-choice (3-AFC) ascending concentration method under two conditions (Orlistat day vs. Control day). To control for olfactory input, subjects will be assessed wearing noseclips.
2. Determine the effect of CD36 variants on fat taste perception in humans. Hypothesis: SNPs that associate with reduced CD36 expression will be associated with higher FFA and TAG detection thresholds

To test this hypothesis we will measure triolein and oleic acid taste detection thresholds in subjects who carry of the common CD36 e-SNP rs1761667 (i.e. a SNP that significantly reduces CD36 level and has a minor allele frequency of 38-48%). We expect subjects who are at least heterozygous for the expression reducing allele to have higher triolein and oleic acid taste detection thresholds compared to non-carrier subjects.

Eligibility criteria: Inclusion Criteria:

* Body Mass Index greater than 30 kg/m²

Exclusion Criteria:

* smokers or who quit smoking less than six months ago
* pregnancy
* breastfeeding
* diabetes
* taking medications that might affect taste perception
* previous malabsorptive or restrictive intestinal surgery

Primary outcomes:
measure: Oleic Acid Detection Level
timeFrame: Ranges from 5 days after screening to several weeks, pending availablity of participant.
measure: Triolein Detection
timeFrame: Ranges from 5 days after screening to several weeks, pending availablity of participant.
Secondary outcomes:
Other outcomes:
Locations:
city: Saint Louis
country: United States
facility: Washington University School of Medicine
state: Missouri
Study officials:
affiliation: Washington University School of Medicine
name: Marta Y Pepino de Gruev, Ph.D.
role: PRINCIPAL_INVESTIGATOR
References: