ObesityBariatricNCT02757638
Omics Profiling of Weight Loss With Bariatric Surgery
A study testing Stable isotope infusion in people with Obesity and Surgery, run by Texas A&M University at 1 site in United States.
Trial summary
Understanding how foods and nutrients are digested, absorbed and metabolized when weight is stable and during weight loss induced by bariatric surgery procedure using the technologies of genomics, transcriptomics, proteomics, metabolomics and fluxomics ("omics") will enable generation of new hypotheses that could… Read more about this study
- Who is it for?
- Ages 18 years and olderHealthy volunteers can take part
- What is being tested?
- Stable isotope infusion
- Type of treatment
- Injection or infusion
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 7 participants
- Where
- 1 siteUnited States
- Study dates
- 25 Feb 2016to 29 Jun 2018
- Phase
- Interventional
- Are there results?
- None posted in the registry
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 18 years and older
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- Diagnosed with morbid obesity (defined as BMI > 40 kg/m2 or BMI > 35 kg/m2 with at least one serious comorbidity (1991 NIH compendium guidelines))
- Scheduled for bariatric surgery
- Age 18 years and older
- Ability to lie in supine or elevated position for 9 hours
- Willingness and ability to comply with the protocol
- Healthy male or female according to the investigator's or appointed staff's judgment
Show all 10Show fewer
- Ability to walk, sit down and stand up independently
- Age 18 years or older
- Ability to lie in supine or elevated position for 9 hours
- Willingness and ability to comply with the protocol
Who cannot join
- Any condition that may interfere with the definition 'healthy subject' according to the investigator's judgment (for healthy control group only)
- Presence of fever within the last 3 days
- Untreated metabolic diseases including hepatic or renal disorder unrelated to the primary disease
- Presence of acute illness or metabolically unstable chronic illness unrelated to the primary disease
- (Possible) pregnancy
- Any other condition according to the PI or nurse that would interfere with the study or safety of the patient
- Failure to give informed consent
- Use of protein or amino acid containing nutritional supplements within 3 days of first test day
Trial locations and contacts
1 site in 1 country.
United States1 site
Texas A&M University-CTRAL
College Station, Texas, 77843
About this study
Official title: Omics Profiling of the Response to Food and Variability of Weight Loss With Bariatric Surgery
Understanding how foods and nutrients are digested, absorbed and metabolized when weight is stable and during weight loss induced by bariatric surgery procedure using the technologies of genomics, transcriptomics, proteomics, metabolomics and fluxomics ("omics") will enable generation of new hypotheses that could explain the inter-individual differences in weight loss and could lead to optimization and individualization of therapies designed to lose weight.
Read the detailed description
The overarching hypothesis is that there are baseline, pre- and post-surgery combinations of 'omics' signatures in response to food and nutrients that explain the weight loss response of obese subjects to the pre-operative very low calorie (VLC) diet and to bariatric surgery.
In order to address the general hypothesis the following specific aims will be addressed:
Specific Aim 1: To test the hypothesis that there is a combination of 'omics' parameters in response to a defined meal that discriminate between morbidly obese subjects and normal weight subjects.
Specific Aim 2: To test the hypothesis that variation in % weight loss to the VLC diet prior to bariatric surgery is related to baseline genomic markers, gene expression profile, proteomic and metabolomic signatures as well as baseline metabolic and substrates fluxomics response to a defined meal.
Specific Aim 2: To test the hypothesis that variation in % weight loss 3 months after bariatric surgery is related to baseline genomic markers, gene expression profile, proteomic and metabolomic signatures as well as baseline metabolic and substrates fluxomics response to a defined meal.
Specific Aim 3: To test whether there are "omics" characteristics post-surgery that track with variability in weight loss at 3 months.
The benefit of these experiments will be the knowledge gained from understanding the variation in % weight loss to the medically required VLC diet prior to bariatric surgery, and to bariatric surgery, in relation to baseline genomic markers, gene expression profile, proteomic and metabolomic signatures as well as baseline metabolic and substrates fluxomics response to a defined meal in obese and healthy adults.
- Being tested
- Stable isotope infusion
- Medical subject headings
- Obesity
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Stable isotope infusionOther
such as glycerol, D2O, tyrosine, phenylalanine, glucose, arginine, and citrulline
| Study group | Role | What they receive |
|---|---|---|
| Healthy matched controls | Experimental | screening visit: body weight and composition by DXA, height, and vital signs will be assessed. Subjects may sign a medical release form to obtain medical and psychological information about them that will help determine study eligibility or can be used for later coding.
study day: muscle mass and function tests, resting energy expenditure, stable isotope infusions with blood draws, and questionnaires regarding quality of life, mood and depression, diet. Receives: Other: Stable isotope infusion |
| Obese subjects | Experimental | screening visit: body weight and composition by DXA, height, and vital signs will be assessed. Subjects may sign a medical release form to obtain medical and psychological information about them that will help determine study eligibility or can be used for later coding.
3 study days (one baseline, one pre-surgery, one post-surgery): muscle mass and function tests, resting energy expenditure, stable isotope infusions with blood draws, and questionnaires regarding quality of life, mood and depression, diet. Receives: Other: Stable isotope infusion |
What is being measured
The primary outcome is the main question the study is designed to answer.
Net whole-body protein synthesis
Change in whole-body protein synthesis rate after intake of meal
Measured: 0, 2, 5, 10, 15, 20, 30, 40, 50, 60, 90, 120, 150, 180, 210, 225, 240, 260, 280, 300, 320, 340, 360 ± 5 min
Secondary outcomes (17)
Group differences in state of mood as measured by the Hospital Anxiety and Depression Scale (HADS),
a fourteen item self-assessment scale. Seven of the items related to anxiety and seven relate to depression. Each item on the questionnaire is scored from 0-3 and this means that a person can score between 0 (no symptoms) and 21 (severe symptoms) for either anxiety or depression.
Measured: Postabsorptive state during 3 hours and change after feeding on study day 1 and the change from day 2 and day 3 (obese only)
Executive Function-Adolescent/Adult Sensory Profile (ASP):
a standardized self-questionnaire that generates an individualized profile of sensory processing across four quadrants: low registration, sensation seeking, sensory sensitivity, and sensation avoiding.
Measured: Postabsorptive state during 3 hours and change after feeding on study day 1 and the change from day 2 and day 3 (obese only)
Group differences in quality of life as measured by Short Form (36) Health Survey (SF36)
self administered questionnaire that measures each of the following eight health concepts: Physical Functioning (PF); Role-Physical (RP); Bodily Pain (BP); General Health (GH); Vitality (VT); Social Functioning (SF); Role-Emotional (RE); Mental Health (MH) as well as a reported Health Transition item (HT).
Measured: Postabsorptive state during 3 hours and change after feeding on study day 1 and the change from day 2 and day 3 (obese only)
Group differences in activity as measured by Physical Activity Scale for the Elderly (PASE)
questionnaire is intended for use in an elderly population and focuses on 3 types of activities: leisure time activities, household activities and work-related activities.
Measured: Postabsorptive state during 3 hours and change after feeding on study day 1 and the change from day 2 and day 3 (obese only)
Group differences in attention and executive functions as measured by Stroop Color-Word Test (SCWT),
a word page with words printed in black ink, a color page with blocks printed in color, and a color-word page where the color and the word do not match. The examinee reads the words or names the ink colors as quickly as possible within a time limit. Measures selective attention and inhibitory control. The total time in seconds was reported for each trial.
Measured: Postabsorptive state during 3 hours and change after feeding on study day 1 and the change from day 2 and day 3 (obese only)
Group differences in state of mood as measured by the Profile of Mood State (POMS)
A psychological distress scale to measure mood disturbance in 6 domains - fatigue-inertia, vigor-activity, tension-anxiety, depression-dejection, anger-hostility, and confusion-bewilderment. Healthy populations take 3 to 7 minutes to complete, and others may take up a bit longer.
Measured: Postabsorptive state during 3 hours and change after feeding on study day 1 and the change from day 2 and day 3 (obese only)
Group differences in learning and memory as measured by Controlled Oral Word Association Test (COWAT),
Controlled Oral Word Association Test (COWAT): The examinee is required to say as many words as they can think of in one minute that begin with a given letter of the alphabet. The task contains three trials. Measures phonetic verbal fluency. The raw score (total and mean words recorded across the three trials) was reported.
Measured: Postabsorptive state during 3 hours and change after feeding on study day 1 and the change from day 2 and day 3 (obese only)
Group differences in learning and memory as measured by Auditory Verbal Learning Test (AVLT)
Auditory Verbal Learning Test (AVLT): a verbal episodic memory test that evaluates a wide diversity of functions: short-term auditory-verbal memory, rate of learning, retention and recognition of information.
Measured: Postabsorptive state during 3 hours and change after feeding on study day 1 and the change from day 2 and day 3 (obese only)
Group differences in attention and executive functions as measured by PASAT
a measure of cognitive function that assesses auditory information processing speed and flexibility, as well as calculation ability.
Measured: Postabsorptive state during 3 hours and change after feeding on study day 1 and the change from day 2 and day 3 (obese only)
Group differences in attention and executive functions as measured by Trail Making Test (TMT),
In Part A, the examinee is instructed to connect a set of 25 circles with numbers as quickly as possible while maintaining accuracy. In Part B, the examinee is instructed to connect a set of 25 circles, alternating between numbers and letters, as quickly as possible while maintaining accuracy. Measures attentional resources and is a measure of the frontal lobe "executive" functions of visual search, set-switching and mental flexibility. The total time in seconds was reported for each measure.
Measured: Postabsorptive state during 3 hours and change after feeding on study day 1 and the change from day 2 and day 3 (obese only)
Group differences in overall cognitive abilities as measured by Montreal Cognitive Assessment (MoCA)
assesses several cognitive domains and is used for the screening of mild cognitive impairment. Total scores range from 0-30 with lower scores indicating decreased functioning.
Measured: Postabsorptive state during 3 hours and change after feeding on study day 1 and the change from day 2 and day 3 (obese only)
Group differences in attention and executive functions as measured by Brief-A
a standardized self-report that captures views of an adult's executive functions or self-regulation in his or her everyday environment.
Measured: Postabsorptive state during 3 hours and change after feeding on study day 1 and the change from day 2 and day 3 (obese only)
Skeletal muscle strength
handgrip and kin-com 1-leg test
Measured: on study day 1 and the change from day 2 and day 3 (obese only)
diet recall
The subject is asked to recall in detail all the food and drink consumed during the 24 hours prior to the test day.
Measured: on study day 1 and the change from day 2 and day 3 (obese only)
Respiratory muscle strength
Maximum inhalation and exhalation pressure
Measured: on study day 1 and the change from day 2 and day 3 (obese only)
Body Composition
Body composition as measured by Dual-Energy X-ray Absorptiometry on study day 1 and the change from day 2 and day 3 (obese only)
Measured: on study day 1 and the change from day 2 and day 3 (obese only)
Gut function
Digestion of the stable tracers of amino acid
Measured: In postabsorptive and prandial state every 20 minutes up to 6 hours before each sip feeding on study day
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted2 May 2016 (estimated)
- Study start25 Feb 2016
- Primary completion29 Jun 2018
- Study completion29 Jun 2018
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for ObesityStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Supportive care
- Allocation
- Non-randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Enrolment
- 7 participants (actual)
Sponsor and investigators
- Lead sponsor
- Texas A&M University
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Marielle PKJ Engelen, PhD, Texas A&M University
- Investigators
- Marielle Engelen, PhD, Principal investigator, Texas A&M University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT02757638
- Sponsor's protocol ID
- 2014-0651
- Acronym
- Bariatric
- Status last verified
- Sep 2025
- First submitted
- 1 Feb 2016
- Last updated
- 30 Sep 2025
- Results posted
- No
- Data monitoring committee
- No
- Individual data sharing
- No
Publications
Wierzchowska-McNew RA, Engelen MPKJ, Thaden JJ, Ten Have GAM, Deutz NEP. Obesity- and sex-related metabolism of arginine and nitric oxide in adults. Am J Clin Nutr. 2022 Dec 19;116(6):1610-1620. doi: 10.1093/ajcn/nqac277.
PubMed 36166849
Study at a glance
From the registry record, last updated by the sponsor on 30 Sep 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Omics Profiling of the Response to Food and Variability of Weight Loss With Bariatric Surgery
- ClinicalTrials.gov ID
- NCT02757638
- Acronym / sponsor ID
- Bariatric / 2014-0651
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 7 participants (actual)
- Lead sponsor
- Texas A&M UniversityUniversity, hospital or other
- Study start
- 25 Feb 2016 (actual)
- Primary completion
- 29 Jun 2018 (actual)
- Study completion
- 29 Jun 2018 (actual)
- First posted
- 2 May 2016 (estimated)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Understanding how foods and nutrients are digested, absorbed and metabolized when weight is stable and during weight loss induced by bariatric surgery procedure using the technologies of genomics, transcriptomics, proteomics, metabolomics and fluxomics ("omics") will enable generation of new hypotheses that could explain the inter-individual differences in weight loss and could lead to optimization and individualization of therapies designed to lose weight.
Detailed description
The overarching hypothesis is that there are baseline, pre- and post-surgery combinations of 'omics' signatures in response to food and nutrients that explain the weight loss response of obese subjects to the pre-operative very low calorie (VLC) diet and to bariatric surgery.
In order to address the general hypothesis the following specific aims will be addressed:
Specific Aim 1: To test the hypothesis that there is a combination of 'omics' parameters in response to a defined meal that discriminate between morbidly obese subjects and normal weight subjects.
Specific Aim 2: To test the hypothesis that variation in % weight loss to the VLC diet prior to bariatric surgery is related to baseline genomic markers, gene expression profile, proteomic and metabolomic signatures as well as baseline metabolic and substrates fluxomics response to a defined meal.
Specific Aim 2: To test the hypothesis that variation in % weight loss 3 months after bariatric surgery is related to baseline genomic markers, gene expression profile, proteomic and metabolomic signatures as well as baseline metabolic and substrates fluxomics response to a defined meal.
Specific Aim 3: To test whether there are "omics" characteristics post-surgery that track with variability in weight loss at 3 months.
The benefit of these experiments will be the knowledge gained from understanding the variation in % weight loss to the medically required VLC diet prior to bariatric surgery, and to bariatric surgery, in relation to baseline genomic markers, gene expression profile, proteomic and metabolomic signatures as well as baseline metabolic and substrates fluxomics response to a defined meal in obese and healthy adults.
Study design
- Primary purpose
- Supportive care
- Allocation
- Non-randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Healthy matched controls | Experimental | Other: Stable isotope infusionscreening visit: body weight and composition by DXA, height, and vital signs will be assessed. Subjects may sign a medical release form to obtain medical and psychological information about them that will help determine study eligibility or can be used for later coding. study day: muscle mass and function tests, resting energy expenditure, stable isotope infusions with blood draws, and questionnaires regarding quality of life, mood and depression, diet. |
| Obese subjects | Experimental | Other: Stable isotope infusionscreening visit: body weight and composition by DXA, height, and vital signs will be assessed. Subjects may sign a medical release form to obtain medical and psychological information about them that will help determine study eligibility or can be used for later coding. 3 study days (one baseline, one pre-surgery, one post-surgery): muscle mass and function tests, resting energy expenditure, stable isotope infusions with blood draws, and questionnaires regarding quality of life, mood and depression, diet. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (10 listed)
- Diagnosed with morbid obesity (defined as BMI > 40 kg/m2 or BMI > 35 kg/m2 with at least one serious comorbidity (1991 NIH compendium guidelines))
- Scheduled for bariatric surgery
- Age 18 years and older
- Ability to lie in supine or elevated position for 9 hours
- Willingness and ability to comply with the protocol
Key exclusion criteria (8 listed)
- Any condition that may interfere with the definition 'healthy subject' according to the investigator's judgment (for healthy control group only)
- Presence of fever within the last 3 days
- Untreated metabolic diseases including hepatic or renal disorder unrelated to the primary disease
- Presence of acute illness or metabolically unstable chronic illness unrelated to the primary disease
- (Possible) pregnancy
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Stable isotope infusionsuch as glycerol, D2O, tyrosine, phenylalanine, glucose, arginine, and citrulline | Other | Healthy matched controls, Obese subjects |
Primary outcome
Net whole-body protein synthesis
Time frame: 0, 2, 5, 10, 15, 20, 30, 40, 50, 60, 90, 120, 150, 180, 210, 225, 240, 260, 280, 300, 320, 340, 360 ± 5 min
Change in whole-body protein synthesis rate after intake of meal
17 secondary outcomes
Group differences in state of mood as measured by the Hospital Anxiety and Depression Scale (HADS),
Time frame: Postabsorptive state during 3 hours and change after feeding on study day 1 and the change from day 2 and day 3 (obese only)
Executive Function-Adolescent/Adult Sensory Profile (ASP):
Time frame: Postabsorptive state during 3 hours and change after feeding on study day 1 and the change from day 2 and day 3 (obese only)
Group differences in quality of life as measured by Short Form (36) Health Survey (SF36)
Time frame: Postabsorptive state during 3 hours and change after feeding on study day 1 and the change from day 2 and day 3 (obese only)
Group differences in activity as measured by Physical Activity Scale for the Elderly (PASE)
Time frame: Postabsorptive state during 3 hours and change after feeding on study day 1 and the change from day 2 and day 3 (obese only)
Group differences in attention and executive functions as measured by Stroop Color-Word Test (SCWT),
Time frame: Postabsorptive state during 3 hours and change after feeding on study day 1 and the change from day 2 and day 3 (obese only)
Group differences in state of mood as measured by the Profile of Mood State (POMS)
Time frame: Postabsorptive state during 3 hours and change after feeding on study day 1 and the change from day 2 and day 3 (obese only)
Group differences in learning and memory as measured by Controlled Oral Word Association Test (COWAT),
Time frame: Postabsorptive state during 3 hours and change after feeding on study day 1 and the change from day 2 and day 3 (obese only)
Group differences in learning and memory as measured by Auditory Verbal Learning Test (AVLT)
Time frame: Postabsorptive state during 3 hours and change after feeding on study day 1 and the change from day 2 and day 3 (obese only)
Group differences in attention and executive functions as measured by PASAT
Time frame: Postabsorptive state during 3 hours and change after feeding on study day 1 and the change from day 2 and day 3 (obese only)
Group differences in attention and executive functions as measured by Trail Making Test (TMT),
Time frame: Postabsorptive state during 3 hours and change after feeding on study day 1 and the change from day 2 and day 3 (obese only)
Group differences in overall cognitive abilities as measured by Montreal Cognitive Assessment (MoCA)
Time frame: Postabsorptive state during 3 hours and change after feeding on study day 1 and the change from day 2 and day 3 (obese only)
Group differences in attention and executive functions as measured by Brief-A
Time frame: Postabsorptive state during 3 hours and change after feeding on study day 1 and the change from day 2 and day 3 (obese only)
Skeletal muscle strength
Time frame: on study day 1 and the change from day 2 and day 3 (obese only)
diet recall
Time frame: on study day 1 and the change from day 2 and day 3 (obese only)
Respiratory muscle strength
Time frame: on study day 1 and the change from day 2 and day 3 (obese only)
Body Composition
Time frame: on study day 1 and the change from day 2 and day 3 (obese only)
Gut function
Time frame: In postabsorptive and prandial state every 20 minutes up to 6 hours before each sip feeding on study day
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 30 Sep 2025.
- Derived from this study: PubMed 36166849Wierzchowska-McNew RA, Engelen MPKJ, Thaden JJ, Ten Have GAM, Deutz NEP. Obesity- and sex-related metabolism of arginine and nitric oxide in adults. Am J Clin Nutr. 2022 Dec 19;116(6):1610-1620. doi: 10.1093/ajcn/nqac277.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Marielle Engelen, PhD principal investigator
Texas A&M University
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Stable isotope infusion in people with Obesity and Surgery, run by Texas A&M University at 1 site in United States.
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 10 inclusion and 8 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 30 Sep 2025. 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 United States. 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?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
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?
Net whole-body protein synthesis (time frame: 0, 2, 5, 10, 15, 20, 30, 40, 50, 60, 90, 120, 150, 180, 210, 225, 240, 260, 280, 300, 320, 340, 360 ± 5 min). 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 NCT02757638, 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 30 Sep 2025.