Effects of Gastric Bypass Surgery and Calcium Metabolism and the Skeleton

Obesity, Morbid Clinical Trial

Official title:

Effects of Gastric Bypass Surgery on Calcium Metabolism and the Skeleton

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT01330914
• Other study ID #: ENDB-007-10F
• Secondary ID: 1IK2CX000549-01
• Status: Completed
• Start date: July 2011
• Est. completion date: January 2015

Study information

• Verified date: February 2019
• Source: VA Office of Research and Development
• Contact: n/a
• Is FDA regulated: No
• Study type: Observational

Clinical 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. 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.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 55
• Est. completion date: January 2015
• Est. primary completion date: April 2014
• Accepts healthy volunteers: No
• Gender: All
• Age group: 25 Years to 70 Years

Eligibility

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

Related Conditions & MeSH terms

• Gastric Bypass
• Obesity, Morbid

Locations

Country	Name	City	State
United States	San Francisco VA Medical Center, San Francisco, CA	San Francisco	California

Sponsors (1)

Lead Sponsor	Collaborator
VA Office of Research and Development

Country where clinical trial is conducted

United States, 

References & Publications (2)

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. do — View Citation

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 Stat — View Citation

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	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	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.	12 months post-operatively (between baseline and 12 months)
Secondary	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.	12 months post-operatively (between baseline and 12 months)