Effects of Gastric Bypass Surgery and Calcium Metabolism and the Skeleton

NCT01330914 | Completed Results

• 2 other identifiers: ENDB-007-10F1IK2CX000549-01
• Study Type: observational
• Target: 55
• Locations: 1 country
• Sites: 1

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.

Conditions

Obesity, Morbid; Gastric Bypass

Keywords

Obesity, Morbid; Bariatric Surgery; Gastric Bypass; Calcium Metabolism Disorders; Vitamin D; Bone Density; Body Composition; Weight Loss

Outcome Measures

Primary Outcomes (1)

• 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%.

  6 months (between baseline and 6 months)

Secondary Outcomes (2)

• Areal Bone Mineral Density (BMD) at the Femoral Neck

  12 months post-operatively (between baseline and 12 months)

• Trabecular Number at the Tibia

  12 months post-operatively (between baseline and 12 months)

Study Arms (1)

Gastric Bypass Surgery Patients

Obese men and women undergoing gastric bypass surgery

Eligibility Criteria

• Age: 25 Years - 70 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)
• Sampling Method: Non-Probability Sample

Study Population

Men and women 25 to 70 years old scheduled to undergo gastric bypass surgery

You may qualify if:

• 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.

You may not qualify if:

• 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

Sponsors & Collaborators

• VA Office of Research and Development: lead

Study Sites (1)

San Francisco VA Medical Center, San Francisco, CA

San Francisco, California, 94121, United States

Location

Related Publications (3)

• 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.

  PMID: 25640580 RESULT

• Schafer 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.

  PMID: 25603463 RESULT

• Chakhtoura 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.

  PMID: 39351881 DERIVED

Biospecimen

Retention: SAMPLES WITHOUT DNA

serum, urine

MeSH Terms

Conditions

Obesity, Morbid; Calcium Metabolism Disorders; Weight Loss

Condition Hierarchy (Ancestors)

Obesity; Overweight; Overnutrition; Nutrition Disorders; Nutritional and Metabolic Diseases; Body Weight; Signs and Symptoms; Pathological Conditions, Signs and Symptoms; Metabolic Diseases; Body Weight Changes

Results Point of Contact

• Title: Dr. Anne Schafer
• Organization: San Francisco Veterans Affairs Medical Center

anne.schafer@va.gov

(415) 221-4810

Study Officials

• Anne L Schafer, MD

  San Francisco VA Medical Center, San Francisco, CA

  PRINCIPAL INVESTIGATOR

Publication Agreements

• PI is Sponsor Employee: No
• Restrictive Agreement: No

Study Design

• Study Type: observational
• Observational Model: COHORT
• Time Perspective: PROSPECTIVE
• Sponsor Type: FED
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: April 5, 2011
• First Posted: April 7, 2011
• Study Start: July 1, 2011
• Primary Completion: April 1, 2014
• Study Completion: January 1, 2015
• Last Updated: March 15, 2019
• Results First Posted: January 7, 2016

Record last verified: 2019-02

Locations

US (1)