ObesityNCT04350892
Cerebrospinal Fluid Biomarkers in Bariatric Surgery
A study testing Roux-en-Y Gastric Bypass (RYGB), Sleeve Gastrectomy (SG) and Very Low Calorie Diet (VLCD) in people with Obesity, run by Columbia University at 1 site in United States.
Trial summary
The goal of this project is to understand why bariatric surgery is such an effective treatment for obesity with a focus on brain mechanisms. Cerebrospinal fluid (CSF) neuropeptide, hormone and protein levels will be measured as a surrogate for changes in brain activity in participants before and after bariatric… Read more about this study
- Who is it for?
- Ages 18 to 65 yearsHealthy volunteers can take part
- Conditions the study is for
- Obesity
- What is being tested?
- Roux-en-Y Gastric Bypass (RYGB), Sleeve Gastrectomy (SG) and Very Low Calorie Diet (VLCD)
- Type of treatment
- Surgery or procedure, Lifestyle or therapy programme
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 51 participants
- Where
- 1 siteUnited States
- Study dates
- 20 Oct 2020to 29 Dec 2025
- 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 to 65 years
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- 18-65 years old
- BMI 35-55
Who cannot join
- No clinically significant medical conditions
- No use of tobacco
- No alcohol or drug abuse
- No recent weight change (+/-5%) within prior 6 months
- No medications that may affect body weight or blood glucose
- No diabetes medications, beta-blockers, opiates or glucocorticoids
- No pregnancy, breastfeeding, or planning to become pregnant during the study (diet group only)
- No lactose intolerance
Trial locations and contacts
1 site in 1 country.
United States1 site
Columbia University Medical Center
New York, New York, 10032
About this study
Official title: Changes in Cerebrospinal Fluid Biomarkers After Bariatric Surgery
The goal of this project is to understand why bariatric surgery is such an effective treatment for obesity with a focus on brain mechanisms. Cerebrospinal fluid (CSF) neuropeptide, hormone and protein levels will be measured as a surrogate for changes in brain activity in participants before and after bariatric surgery as compared with participants before and after diet-induced weight loss. The investigators are studying neuropeptides and hormones that are know to be involved with the regulation of appetite and body weight to determine if some of the changes that are expected to occur after diet-induced weight loss do not occur after bariatric surgery. In addition, proteomic analysis will be used to uncover new protein biomarkers that are unique to surgical weight loss. The results of these studies will help explain why bariatric surgery is so effective in achieving long-term weight loss. Understanding how the central nervous system responds to bariatric surgery could help the development of alternative nonsurgical therapies for obesity and its metabolic complications.
Read the detailed description
Peripheral metabolic signals communicate levels of energy stores to the brain and elicit a host of neuronal responses that maintain energy balance; such regulatory mechanisms make it difficult to maintain diet-induced weight loss. The goal is to understand how these central regulatory mechanisms are circumvented following surgical alterations in the gut in subjects after Roux-en-Y gastric bypass (RYGB) and vertical sleeve gastrectomy (SG) compared to carefully matched diet- induced weight loss controls who achieve weight loss on a low calorie liquid diet. Surgery participants will be patients who have already chosen to have a bariatric surgery procedure with their doctor. Diet participants will be provided with the low calorie liquid diet for approximately 3 months and will be monitored weekly throughout the study.
Surgery participants will be studied at 3 time-points:
- Before the intervention
- After surgery at 10-15% weight loss
- At 12 months after surgery
Low calorie diet participants will be studied at 2 time-points:
- Before intervention
- At 10-15% weight loss (approximately 12 weeks on the diet)
At each time-point subjects will have a lumbar puncture (spinal tap) for cerebrospinal fluid (CSF) sampling and blood will be collected in the fasting state and in response to a liquid meal challenge. Body weight, waist and hip circumference will be measured.
- Conditions
- Obesity
- Being tested
- Roux-en-Y Gastric Bypass (RYGB), Sleeve Gastrectomy (SG), Very Low Calorie Diet (VLCD)
- Keywords
- Obesity, Bariatric Surgery, Gastric Bypass, Sleeve Gastrectomy, Weight Loss, Low Calorie Diet
- Medical subject headings
- Obesity, Weight Loss
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Roux-en-Y Gastric Bypass (RYGB)Procedure or surgery
This surgery is often called gastric bypass. It is a weight-loss surgery that involves creating a small stomach pouch and bypassing part of the small intestine.
If you decide with your doctor to have gastric bypass, you can be enrolled on this arm of the study. A surgery date should be pending before the investigators screen you for the study. The study does not cover the cost of the Roux-en-Y gastric bypass.
Sleeve Gastrectomy (SG)Procedure or surgery
Sleeve gastrectomy, is a weight-loss surgery that involves removing about 80% of the stomach.
If you decide with your doctor to have sleeve gastrectomy, you can be enrolled on this arm of the study. A surgery date should be pending before the investigators screen you for the study. The study does not cover the cost of the sleeve gastrectomy.
Very Low Calorie Diet (VLCD)Behavioural
Weight loss with calorie restricted liquid diet. Participants will be placed on a 800 kcal/day diet for meal replacement (Optifast) provided by the investigator for 12 weeks. Participants will be monitored weekly by the study dietician and medical staff.
| Study group | Role | What they receive |
|---|---|---|
| Roux-en-Y Gastric Bypass Surgery | Active comparator | Not described Receives: Procedure: Roux-en-Y Gastric Bypass (RYGB) |
| Sleeve Gastrectomy Surgery | Active comparator | Not described Receives: Procedure: Sleeve Gastrectomy (SG) |
| Very Low Calorie Diet | Active comparator | Not described Receives: Behavioral: Very Low Calorie Diet (VLCD) |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change in the levels of cerebrospinal fluid (CSF) proopiomelanocortin (POMC) derived peptides (fmol/ml) that occur in subjects after diet induced weight loss compared to RYGB and SG.
POMC plays a critical role in regulating energy balance and levels decrease in the hypothalamus after diet-induced weight loss; this may lead to weight regain after dieting.
Measured: Up to 12 months
Comparison of changes in the CSF proteome that occur after diet-induced weight-loss compared to RYGB and SG using unbiased proteomic analysis.
Measured: Up to 12 months
Secondary outcomes (2)
Comparison of the changes in Agouti-related protein (AgRP) concentrations (fmol/ml) in CSF and plasma that occur in subjects after diet induced weight loss compared to RYGB and SG.
AgRP is neuropeptide that stimulates food intake and increases after diet-induced weight loss.
Measured: Up to 12 months
Comparison of changes in CSF cortisol (ng/mL) that occur in subjects after diet induced weight loss compared to RYGB and SG.
Measured: Up to 12 months
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted17 Apr 2020
- Study start20 Oct 2020
- Primary completion29 Dec 2025
- Study completion29 Dec 2025
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for ObesityStudies of the same condition, open and under way.
- More trials run by Columbia UniversityThe sponsor's other registered studies.
- 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
- Treatment
- Allocation
- Non-randomised
- Intervention model
- Parallel groups
- Model description
- Cohort
- Masking
- None (open label)
- Enrolment
- 51 participants (actual)
Sponsor and investigators
- Lead sponsor
- Columbia University
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Sharon Wardlaw, Columbia University
- Investigators
- Sharon L Wardlaw, MD, Principal investigator, Columbia University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04350892
- Sponsor's protocol ID
- AAAS8430
- Other IDs
- 1R01DK124465
- Status last verified
- Jan 2026
- First submitted
- 15 Apr 2020
- Last updated
- 28 Jan 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 28 Jan 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Changes in Cerebrospinal Fluid Biomarkers After Bariatric Surgery
- ClinicalTrials.gov ID
- NCT04350892
- Acronym / sponsor ID
- AAAS8430
- Conditions
- Obesity
- Keywords
- Obesity, Bariatric Surgery, Gastric Bypass, Sleeve Gastrectomy, Weight Loss, Low Calorie Diet
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 51 participants (actual)
- Lead sponsor
- Columbia UniversityUniversity, hospital or other
- Collaborators
- National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
- Study start
- 20 Oct 2020 (actual)
- Primary completion
- 29 Dec 2025 (actual)
- Study completion
- 29 Dec 2025 (actual)
- First posted
- 17 Apr 2020 (actual)
- 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.
The goal of this project is to understand why bariatric surgery is such an effective treatment for obesity with a focus on brain mechanisms. Cerebrospinal fluid (CSF) neuropeptide, hormone and protein levels will be measured as a surrogate for changes in brain activity in participants before and after bariatric surgery as compared with participants before and after diet-induced weight loss. The investigators are studying neuropeptides and hormones that are know to be involved with the regulation of appetite and body weight to determine if some of the changes that are expected to occur after diet-induced weight loss do not occur after bariatric surgery. In addition, proteomic analysis will be used to uncover new protein biomarkers that are unique to surgical weight loss. The results of these studies will help explain why bariatric surgery is so effective in achieving long-term weight loss. Understanding how the central nervous system responds to bariatric surgery could help the development of alternative nonsurgical therapies for obesity and its metabolic complications.
Detailed description
Peripheral metabolic signals communicate levels of energy stores to the brain and elicit a host of neuronal responses that maintain energy balance; such regulatory mechanisms make it difficult to maintain diet-induced weight loss. The goal is to understand how these central regulatory mechanisms are circumvented following surgical alterations in the gut in subjects after Roux-en-Y gastric bypass (RYGB) and vertical sleeve gastrectomy (SG) compared to carefully matched diet- induced weight loss controls who achieve weight loss on a low calorie liquid diet. Surgery participants will be patients who have already chosen to have a bariatric surgery procedure with their doctor. Diet participants will be provided with the low calorie liquid diet for approximately 3 months and will be monitored weekly throughout the study.
Surgery participants will be studied at 3 time-points:
- Before the intervention
- After surgery at 10-15% weight loss
- At 12 months after surgery
Low calorie diet participants will be studied at 2 time-points:
- Before intervention
- At 10-15% weight loss (approximately 12 weeks on the diet)
At each time-point subjects will have a lumbar puncture (spinal tap) for cerebrospinal fluid (CSF) sampling and blood will be collected in the fasting state and in response to a liquid meal challenge. Body weight, waist and hip circumference will be measured.
Study design
- Primary purpose
- Treatment
- Allocation
- Non-randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 3
- Model description
- Cohort
| Arm | Type | Receives |
|---|---|---|
| Roux-en-Y Gastric Bypass Surgery | Active comparator | Procedure: Roux-en-Y Gastric Bypass (RYGB) |
| Sleeve Gastrectomy Surgery | Active comparator | Procedure: Sleeve Gastrectomy (SG) |
| Very Low Calorie Diet | Active comparator | Behavioral: Very Low Calorie Diet (VLCD) |
Who may qualify
- Ages
- 18 to 65 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (2 listed)
- 18-65 years old
- BMI 35-55
Key exclusion criteria (8 listed)
- No clinically significant medical conditions
- No use of tobacco
- No alcohol or drug abuse
- No recent weight change (+/-5%) within prior 6 months
- No medications that may affect body weight or blood glucose
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 |
|---|---|---|
| Roux-en-Y Gastric Bypass (RYGB)This surgery is often called gastric bypass. It is a weight-loss surgery that involves creating a small stomach pouch and bypassing part of the small intestine. If you decide with your doctor to have gastric bypass, you can be enrolled on this arm of the study. A surgery date should be pending before the investigators screen you for the study. The study does not cover the cost of the Roux-en-Y gastric bypass. | Procedure or surgery | Roux-en-Y Gastric Bypass Surgery |
| Sleeve Gastrectomy (SG)Sleeve gastrectomy, is a weight-loss surgery that involves removing about 80% of the stomach. If you decide with your doctor to have sleeve gastrectomy, you can be enrolled on this arm of the study. A surgery date should be pending before the investigators screen you for the study. The study does not cover the cost of the sleeve gastrectomy. | Procedure or surgery | Sleeve Gastrectomy Surgery |
| Very Low Calorie Diet (VLCD)Weight loss with calorie restricted liquid diet. Participants will be placed on a 800 kcal/day diet for meal replacement (Optifast) provided by the investigator for 12 weeks. Participants will be monitored weekly by the study dietician and medical staff. | Behavioural | Very Low Calorie Diet |
Primary outcome
Change in the levels of cerebrospinal fluid (CSF) proopiomelanocortin (POMC) derived peptides (fmol/ml) that occur in subjects after diet induced weight loss compared to RYGB and SG.
Time frame: Up to 12 months
POMC plays a critical role in regulating energy balance and levels decrease in the hypothalamus after diet-induced weight loss; this may lead to weight regain after dieting.
Comparison of changes in the CSF proteome that occur after diet-induced weight-loss compared to RYGB and SG using unbiased proteomic analysis.
Time frame: Up to 12 months
2 secondary outcomes
Comparison of the changes in Agouti-related protein (AgRP) concentrations (fmol/ml) in CSF and plasma that occur in subjects after diet induced weight loss compared to RYGB and SG.
Time frame: Up to 12 months
Comparison of changes in CSF cortisol (ng/mL) that occur in subjects after diet induced weight loss compared to RYGB and SG.
Time frame: Up to 12 months
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 28 Jan 2026.
- 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.
Sharon L Wardlaw, MD principal investigator
Columbia 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 Roux-en-Y Gastric Bypass (RYGB), Sleeve Gastrectomy (SG) and Very Low Calorie Diet (VLCD) in people with Obesity, run by Columbia 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 2 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 28 Jan 2026. 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?
Change in the levels of cerebrospinal fluid (CSF) proopiomelanocortin (POMC) derived peptides (fmol/ml) that occur in subjects after diet induced weight loss compared to RYGB and SG. (time frame: Up to 12 months). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
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 28 Jan 2026.