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Effects of Gastric Bypass Surgery and Calcium Metabolism and the Skeleton

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ClinicalTrials.gov Identifier: NCT01330914
Recruitment Status : Completed
First Posted : April 7, 2011
Results First Posted : January 7, 2016
Last Update Posted : March 15, 2019
Sponsor:
Information provided by (Responsible Party):
VA Office of Research and Development

Brief 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. 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.

Condition or disease
Obesity, Morbid Gastric Bypass

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Study Type : Observational
Actual Enrollment : 55 participants
Observational Model: Cohort
Time Perspective: Prospective
Official Title: Effects of Gastric Bypass Surgery on Calcium Metabolism and the Skeleton
Study Start Date : July 2011
Actual Primary Completion Date : April 2014
Actual Study Completion Date : January 2015

Resource links provided by the National Library of Medicine

MedlinePlus related topics: Calcium

Group/Cohort
Gastric Bypass Surgery Patients
Obese men and women undergoing gastric bypass surgery



Primary Outcome Measures :
  1. 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%.



Secondary Outcome Measures :
  1. Areal Bone Mineral Density (BMD) at the Femoral Neck [ Time Frame: 12 months post-operatively (between baseline and 12 months) ]
    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.

  2. Trabecular Number at the Tibia [ Time Frame: 12 months post-operatively (between baseline and 12 months) ]
    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.


Biospecimen Retention:   Samples Without DNA
serum, urine


Information from the National Library of Medicine

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Ages Eligible for Study:   25 Years to 70 Years   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No
Sampling Method:   Non-Probability Sample
Study Population
Men and women 25 to 70 years old scheduled to undergo gastric bypass surgery
Criteria

Inclusion Criteria:

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.

Exclusion Criteria:

  • 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
  • Serum calcium >10.2 mg/dL
  • Calculated creatinine clearance <30 mL/min
  • Weight >350 pounds
  • Wrist circumference >12 inches or calf circumference >17 inches

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT01330914


Locations
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United States, California
San Francisco VA Medical Center, San Francisco, CA
San Francisco, California, United States, 94121
Sponsors and Collaborators
VA Office of Research and Development
Investigators
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Principal Investigator: Anne L Schafer, MD San Francisco VA Medical Center, San Francisco, CA

Publications of Results:
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Responsible Party: VA Office of Research and Development
ClinicalTrials.gov Identifier: NCT01330914     History of Changes
Other Study ID Numbers: ENDB-007-10F
1IK2CX000549-01 ( U.S. NIH Grant/Contract )
First Posted: April 7, 2011    Key Record Dates
Results First Posted: January 7, 2016
Last Update Posted: March 15, 2019
Last Verified: February 2019

Keywords provided by VA Office of Research and Development:
Obesity, Morbid
Bariatric Surgery
Gastric Bypass
Calcium Metabolism Disorders
Vitamin D
Bone Density
Body Composition
Weight Loss

Additional relevant MeSH terms:
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Obesity, Morbid
Obesity
Overnutrition
Nutrition Disorders
Overweight
Body Weight
Signs and Symptoms
Calcium
Calcium, Dietary
Calcium-Regulating Hormones and Agents
Physiological Effects of Drugs
Bone Density Conservation Agents