This site became the new on June 19th. Learn more.
Show more Menu IMPORTANT: Listing of a study on this site does not reflect endorsement by the National Institutes of Health. Talk with a trusted healthcare professional before volunteering for a study. Read more... Menu IMPORTANT: Talk with a trusted healthcare professional before volunteering for a study. Read more... Menu
Give us feedback

Bone Loss After Laparoscopic Roux-en-Y Gastric Bypass

This study has been completed.
Gundersen Lutheran Health System
Information provided by (Responsible Party):
Kara Kallies, Gundersen Lutheran Medical Foundation Identifier:
First received: September 10, 2009
Last updated: September 4, 2015
Last verified: September 2015
The objective of this study is to assess changes bone mineral density and bone metabolism after laparoscopic Roux-en-Y gastric bypass surgery. The investigators hypothesize that weight loss after laparoscopic Roux-en-Y gastric bypass surgery will be associated with increased bone turnover, changes in bone metabolism, and loss of bone mass.

Bone Loss Bone Density Gastric Bypass Bariatric Surgery

Study Type: Observational
Study Design: Observational Model: Case-Only
Time Perspective: Prospective
Official Title: Losing More Than Just Weight: Bone Loss After Laparoscopic Roux-en-Y Gastric Bypass

Resource links provided by NLM:

Further study details as provided by Kara Kallies, Gundersen Lutheran Medical Foundation:

Primary Outcome Measures:
  • Evaluate bone densitometry and lab tests to assess changes in bone mass and bone turnover after laparoscopic gastric bypass surgery [ Time Frame: preoperatively and at 6 and 12 months after laparoscopic Roux-en-Y gastric bypass ]

Secondary Outcome Measures:
  • Evaluate weight loss, menopausal and nutritional status to assess correlations with results from bone densitometry and lab values after laparoscopic gastric bypass surgery [ Time Frame: preoperatively, and at 6 and 12 months after laparoscopic Roux-en-Y gastric bypass ]

Biospecimen Retention:   Samples With DNA
whole blood

Enrollment: 40
Study Start Date: April 2007
Study Completion Date: December 2009
Primary Completion Date: November 2009 (Final data collection date for primary outcome measure)
Bone Density Study Group
Morbidly obese, (BMI >40 kg/m2, or 35 kg/m2 with comorbidities) female patients who have given consent to undergo additional testing including bone densitometry, and lab testing preoperatively and at 6 and 12 months after undergoing elective laparoscopic roux-en-Y gastric bypass.

Detailed Description:

Obesity is an increasing problem within the United States. Fifteen million people in the United States are considered morbidly obese, with a body mass index (BMI) greater than 40 kg/m2. A wealth of literature has shown laparoscopic Roux-en Y gastric bypass surgery to be an effective procedure to reduce excess body weight. But a paucity of research examines the effects of laparoscopic Roux-en Y surgery on the skeleton.

Bone remodeling is a complex process involving bone resorption and formation-a process dependent upon local and systemic influences. Obesity is one of these influences that is poorly understood. Obesity is associated with a reduced risk of osteoporosis. Obesity may be protective due to increased weight bearing, increased production of estrogen by adipose tissue, or increased bone formation due to higher levels of insulin.

It is known that weight loss in healthy individuals is associated with bone loss. Several small studies have reported bone loss in patients undergoing vertical band gastroplasty or jejunoileal bypass weight loss surgeries. Other reported metabolic disease disarrangements following weight loss surgery are decreased serum calcium, decreased serum 25-hydroxy vitamin D, and hyperparathyroidism.

In the bariatric literature, weight loss has been associated with an increased risk of bone mineral loss and fracture. Osteoporosis has been described in patients who lost weight after jejunoileal bypass surgery. Premenopausal women appeared to be spared from bone mineral loss, thus indicating a protective effect from the premenopausal state. Bone mineral loss is seen both in premenopausal women and in men after weight loss surgery.

Roux-en Y gastric bypass has been shown to be more effective at weight loss than has the adjustable silicone gastric band. It has also been linked with increased loss of bone mineral density. Another study found an increase in bone turnover as well as a decrease in total bone mass and trochanteric bone density in laparoscopic Roux-en Y gastric bypass patients.

Previous research at our institution has shown a statistically significant increase in the prevalence of hyperparathyroidism in post-gastric bypass patients. However, our previous research did not examine the impact that these hormonal changes impart upon bone density. We have found a statistically significant incidence of vitamin D deficiency in our patients following this surgery. We intend to expand upon our own research as well as that of others by exploring the associations between the development of hyperparathyroidism, bone metabolic derangements, weight loss, and bone density.


Ages Eligible for Study:   30 Years to 65 Years   (Adult)
Sexes Eligible for Study:   Female
Accepts Healthy Volunteers:   No
Sampling Method:   Non-Probability Sample
Study Population
Study population will consist of patients undergoing laparoscopic gastric bypass at a community-based teaching institution

Inclusion Criteria:

  • Morbidly obese female patients undergoing elective laparoscopic Roux-en-Y gastric bypass at a single institution

Exclusion Criteria:

  • Male patients
  • Patients unable to fulfill the study protocol requirements
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its identifier: NCT00975013

United States, Wisconsin
Gundersen Lutheran Health System
La Crosse, Wisconsin, United States, 54601
Sponsors and Collaborators
Gundersen Lutheran Medical Foundation
Gundersen Lutheran Health System
Principal Investigator: Shanu N Kothari, M.D. Gundersen Lutheran Health System
Principal Investigator: Kevin P Riess, M.D. Gundersen Lutheran Medical Foundation; Current Practice: SMDC Health System-Duluth Clinic
  More Information


Responsible Party: Kara Kallies, Academic Researcher, Gundersen Lutheran Medical Foundation Identifier: NCT00975013     History of Changes
Other Study ID Numbers: 2-07-02-009
Study First Received: September 10, 2009
Last Updated: September 4, 2015

Keywords provided by Kara Kallies, Gundersen Lutheran Medical Foundation:
Laparoscopic Gastric Bypass
Morbid Obesity
Bone Mineral Density processed this record on August 21, 2017