Obesity, MorbidNCT01330914
Effects of Gastric Bypass Surgery and Calcium Metabolism and the Skeleton
An observational study of Obesity, Morbid and Gastric Bypass, run by VA Office of Research and Development at 1 site in United States.
Trial summary
Obesity is a chronic illness of staggering proportions. Because weight loss through diet and exercise is difficult to attain and maintain, there has been escalating interest in bariatric surgery, including Roux-en-Y gastric bypass. Read more about this study
- Who is it for?
- Ages 25 to 70 years
- Conditions the study is for
- Obesity, Morbid, Gastric Bypass
- How many people
- 55 participants
- Where
- 1 siteUnited States
- Study dates
- Jul 2011to Jan 2015
- Phase
- Observational
- Are there results?
- Yes, posted in the registrySummary in the doctors' view
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 25 to 70 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Study population: Men and women 25 to 70 years old scheduled to undergo gastric bypass surgery
Who may be able to join
- Scheduled to undergo gastric bypass surgery. Please note that to be eligible, one must already be working with a bariatric surgeon and with plans in place to undergo gastric bypass. This study is unable to arrange or pay for gastric bypass surgery.
Who cannot join
- Perimenopausal women
- Known intestinal malabsorption
- Prior bariatric surgery
- Use of medications known to impact bone and mineral metabolism
- Disease known to affect bone
- Illicit drug use or alcohol use >3 drinks/day
Show all 10Show fewer
- Serum calcium >10.2 mg/dL
- Calculated creatinine clearance <30 mL/min
- Weight >350 pounds
- Wrist circumference >12 inches or calf circumference >17 inches
Trial locations and contacts
1 site in 1 country.
United States1 site
San Francisco VA Medical Center, San Francisco, CA
San Francisco, California, 94121
About this study
Official title: Effects of Gastric Bypass Surgery on Calcium Metabolism and the Skeleton
Obesity is a chronic illness of staggering proportions. Because weight loss through diet and exercise is difficult to attain and maintain, there has been escalating interest in bariatric surgery, including Roux-en-Y gastric bypass. Gastric bypass surgery results in long-term weight loss, dramatic improvement in comorbidities such as diabetes, and decreased mortality. Emerging evidence suggests, however, that gastric bypass may have negative effects on bone health. Because of the serious consequences of osteoporosis and fracture, this is of great concern. This study of the effects of gastric bypass on calcium metabolism and the skeleton may positively impact the clinical care of gastric bypass patients by their surgeons, primary care providers, and endocrinologists. Further, the knowledge gained may inform future investigation into the relationships between obesity, weight loss, and bone biology.
- Conditions
- Obesity, Morbid, Gastric Bypass
- Keywords
- Obesity, Morbid, Bariatric Surgery, Gastric Bypass, Calcium Metabolism Disorders, Vitamin D, Bone Density, Body Composition, Weight Loss
- Medical subject headings
- Obesity, Morbid, Calcium Metabolism Disorders, Weight Loss
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
| Study group | Role | What they receive |
|---|---|---|
| Gastric Bypass Surgery Patients | Obese men and women undergoing gastric bypass surgery |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change in Intestinal Calcium Absorption
Change in fractional calcium absorption, determined by dual stable isotope method.
Fractional calcium absorption is the fraction of ingested calcium that is absorbed, which is expressed here as the percentage of ingested calcium that is absorbed. The 6-month change is the mean difference in percentage absorption between time points. For example, if fractional calcium absorption were to decrease from 30% preoperatively to 25% at the 6-month postoperative time point, the change in fractional calcium absorption would be -5%.
Measured: 6 months (between baseline and 6 months)
Secondary outcomes (2)
Areal Bone Mineral Density (BMD) at the Femoral Neck
Areal BMD at the femoral neck by dual-energy X-ray absorptiometry (DXA). The 12-month change is the percentage change between the 12 month and baseline time points.
Measured: 12 months post-operatively (between baseline and 12 months)
Trabecular Number at the Tibia
Trabecular number at the tibia by high-resolution peripheral quantitative computed tomography (HR-pQCT). The 12-month change is the percentage change between the 12 month and baseline time points. HR-pQCT images were analyzed using the manufacturer's standard clinical evaluation protocol, with trabecular structure extracted using a threshold-based binarization process.
Measured: 12 months post-operatively (between baseline and 12 months)
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted7 Apr 2011 (estimated)
- Study startJul 2011
- Primary completionApr 2014
- Study completionJan 2015
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Posted resultsParticipant flow, outcome measures and adverse events reported by the sponsor.
- Publications (3)Papers the sponsor has linked to this study.
- Other trials for Obesity, MorbidStudies of the same condition, open and under way.
- More trials run by VA Office of Research and DevelopmentThe 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
- Observational
- Observational model
- Cohort
- Time perspective
- Prospective
- Enrolment
- 55 participants (actual)
Sponsor and investigators
- Lead sponsor
- VA Office of Research and Development
- Sponsor type
- US federal agency
- Responsible party
- Sponsor
- Investigators
- Anne L Schafer, MD, Principal investigator, San Francisco VA Medical Center, San Francisco, CA
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT01330914
- Sponsor's protocol ID
- ENDB-007-10F
- Other IDs
- 1IK2CX000549-01
- Status last verified
- Feb 2019
- First submitted
- 5 Apr 2011
- Last updated
- 15 Mar 2019
- Results posted
- Yes, on ClinicalTrials.gov
- Data monitoring committee
- No
Publications
Schafer AL, Weaver CM, Black DM, Wheeler AL, Chang H, Szefc GV, Stewart L, Rogers SJ, Carter JT, Posselt AM, Shoback DM, Sellmeyer DE. Intestinal Calcium Absorption Decreases Dramatically After Gastric Bypass Surgery Despite Optimization of Vitamin D Status. J Bone Miner Res. 2015 Aug;30(8):1377-85. doi: 10.1002/jbmr.2467. Epub 2015 May 21.
PubMed 25640580Schafer AL, Li X, Schwartz AV, Tufts LS, Wheeler AL, Grunfeld C, Stewart L, Rogers SJ, Carter JT, Posselt AM, Black DM, Shoback DM. Changes in vertebral bone marrow fat and bone mass after gastric bypass surgery: A pilot study. Bone. 2015 May;74:140-5. doi: 10.1016/j.bone.2015.01.010. Epub 2015 Jan 17.
PubMed 25603463Chakhtoura MT, Nakhoul NF, Akl EA, Safadi BY, Mantzoros CS, Metzendorf MI, El-Hajj Fuleihan G. Oral vitamin D supplementation for adults with obesity undergoing bariatric surgery. Cochrane Database Syst Rev. 2024 Oct 1;10(10):CD011800. doi: 10.1002/14651858.CD011800.pub2.
PubMed 39351881
Study at a glance
From the registry record, last updated by the sponsor on 15 Mar 2019. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Effects of Gastric Bypass Surgery on Calcium Metabolism and the Skeleton
- ClinicalTrials.gov ID
- NCT01330914
- Acronym / sponsor ID
- ENDB-007-10F
- Conditions
- Obesity, Morbid, Gastric Bypass
- Keywords
- Obesity, Morbid, Bariatric Surgery, Gastric Bypass, Calcium Metabolism Disorders, Vitamin D, Bone Density, Body Composition, Weight Loss
- Study type
- Observational
- Recruitment status
- Completed
- Enrolment
- 55 participants (actual)
- Lead sponsor
- VA Office of Research and DevelopmentUS federal agency
- Study start
- Jul 2011
- Primary completion
- Apr 2014 (actual)
- Study completion
- Jan 2015 (actual)
- First posted
- 7 Apr 2011 (estimated)
- Results
- Posted 7 Jan 2016
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Obesity is a chronic illness of staggering proportions. Because weight loss through diet and exercise is difficult to attain and maintain, there has been escalating interest in bariatric surgery, including Roux-en-Y gastric bypass. Gastric bypass surgery results in long-term weight loss, dramatic improvement in comorbidities such as diabetes, and decreased mortality. Emerging evidence suggests, however, that gastric bypass may have negative effects on bone health. Because of the serious consequences of osteoporosis and fracture, this is of great concern. This study of the effects of gastric bypass on calcium metabolism and the skeleton may positively impact the clinical care of gastric bypass patients by their surgeons, primary care providers, and endocrinologists. Further, the knowledge gained may inform future investigation into the relationships between obesity, weight loss, and bone biology.
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Gastric Bypass Surgery Patients | – | –Obese men and women undergoing gastric bypass surgery |
Who may qualify
- Ages
- 25 to 70 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
- Study population
- Men and women 25 to 70 years old scheduled to undergo gastric bypass surgery
Key inclusion criteria (1 listed)
- Scheduled to undergo gastric bypass surgery. Please note that to be eligible, one must already be working with a bariatric surgeon and with plans in place to undergo gastric bypass. This study is unable to arrange or pay for gastric bypass surgery.
Key exclusion criteria (10 listed)
- Perimenopausal women
- Known intestinal malabsorption
- Prior bariatric surgery
- Use of medications known to impact bone and mineral metabolism
- Disease known to affect bone
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Primary outcome
Change in Intestinal Calcium Absorption
Time frame: 6 months (between baseline and 6 months)
Change in fractional calcium absorption, determined by dual stable isotope method. Fractional calcium absorption is the fraction of ingested calcium that is absorbed, which is expressed here as the percentage of ingested calcium that is absorbed. The 6-month change is the mean difference in percentage absorption between time points. For example, if fractional calcium absorption were to decrease from 30% preoperatively to 25% at the 6-month postoperative time point, the change in fractional calcium absorption would be -5%.
2 secondary outcomes
Areal Bone Mineral Density (BMD) at the Femoral Neck
Time frame: 12 months post-operatively (between baseline and 12 months)
Trabecular Number at the Tibia
Time frame: 12 months post-operatively (between baseline and 12 months)
Results and safety
Loading the posted results from ClinicalTrials.gov…
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 15 Mar 2019.
- Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
- Results publication: PubMed 25640580Schafer AL, Weaver CM, Black DM, Wheeler AL, Chang H, Szefc GV, Stewart L, Rogers SJ, Carter JT, Posselt AM, Shoback DM, Sellmeyer DE. Intestinal Calcium Absorption Decreases Dramatically After Gastric Bypass Surgery Despite Optimization of Vitamin D Status. J Bone Miner Res. 2015 Aug;30(8):1377-85. doi: 10.1002/jbmr.2467. Epub 2015 May 21.
- Results publication: PubMed 25603463Schafer AL, Li X, Schwartz AV, Tufts LS, Wheeler AL, Grunfeld C, Stewart L, Rogers SJ, Carter JT, Posselt AM, Black DM, Shoback DM. Changes in vertebral bone marrow fat and bone mass after gastric bypass surgery: A pilot study. Bone. 2015 May;74:140-5. doi: 10.1016/j.bone.2015.01.010. Epub 2015 Jan 17.
- Derived from this study: PubMed 39351881Chakhtoura MT, Nakhoul NF, Akl EA, Safadi BY, Mantzoros CS, Metzendorf MI, El-Hajj Fuleihan G. Oral vitamin D supplementation for adults with obesity undergoing bariatric surgery. Cochrane Database Syst Rev. 2024 Oct 1;10(10):CD011800. doi: 10.1002/14651858.CD011800.pub2.
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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.
Anne L Schafer, MD principal investigator
San Francisco VA Medical Center, San Francisco, CA
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Obesity, Morbid and Gastric Bypass, run by VA Office of Research and Development 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 1 inclusion and 10 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 15 Mar 2019. 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?
Yes. Results are posted in the registry (first posted 7 Jan 2016). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.
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 Intestinal Calcium Absorption (time frame: 6 months (between baseline and 6 months)). 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 NCT01330914, which also lists 3 linked publications.
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 15 Mar 2019.