Ignite Creation Date:
2024-05-06 @ 8:36 AM
Last Modification Date:
2024-10-26 @ 12:02 PM
Study NCT ID:
NCT02778490
Status:
COMPLETED
Last Update Posted:
2022-10-28
First Post:
2016-05-15
Brief Title:
Effects of Sleeve Gastrectomy on Calcium Metabolism and the Skeleton
Sponsor:
San Francisco Veterans Affairs Medical Center
Organization:
San Francisco Veterans Affairs Medical Center
Study Overview
Official Title:
Effects of Sleeve Gastrectomy on Calcium Metabolism and the Skeleton
Status:
COMPLETED
Status Verified Date:
2022-10
Last Known Status:
None
Delayed Posting:
No
If Stopped, Why?:
Not Stopped
Has Expanded Access:
False
If Expanded Access, NCT#:
N/A
Has Expanded Access, NCT# Status:
N/A
Acronym:
None
Brief Summary:
In this pre-post observational study the investigators will enroll and follow a cohort of about 50 adults undergoing sleeve gastrectomy surgery for weight loss Pre-operatively and at 6 and 12 months post-operatively the investigators will use state-of-the-art metabolic and imaging techniques to evaluate calcium metabolism and skeletal health Specific outcomes include intestinal calcium absorption capacity bone mineral density BMD assessed by dual-energy X-ray absorptiometry DXA and quantitative computed tomography QCT and bone structure assessed by QCT and high-resolution peripheral QCT HR-pQCT
Detailed Description:
Obesity is a chronic disease of staggering proportions Because weight loss through diet and exercise is difficult to attain and maintain there is escalating interest in surgical weight loss procedures including Roux-en-Y gastric bypass Gastric bypass results in marked and durable weight loss and improvement in comorbidities in the general population and in our veteran patients However growing evidence indicates that gastric bypass can have negative effects on the skeleton increasing bone turnover and decreasing bone mineral density BMD This is of critical concern given the tremendous impact of osteoporosis and fracture in both men and women Vitamin D deficiency due to obesity and post-surgical malabsorption may partially explain the decline in bone mass observed after gastric bypass Other factors are likely involved as well such as non-vitamin D-mediated calcium malabsorption signals related to decreased skeletal loading and changes in fat-secreted hormones or estrogen due to changes in fat mass and body composition
We will characterize the effects of gastric bypass on calcium metabolism and the skeleton in a cohort of 80 men and women whose serum 25-hydroxyvitamin D levels are supplemented and maintained at 30 ngmL First we will test the hypothesis that intestinal calcium absorption is impaired following gastric bypass even in the setting of vitamin D sufficiency We will do this by measuring fractional calcium absorption pre-operatively and 6 months post-operatively using dual stable isotopic tracers Aim 1 Then we will test the hypothesis that gastric bypass results in decreased BMD and in structural changes associated with impaired skeletal strength We will do this by performing dual-energy X-ray absorptiometry DXA quantitative computed tomography QCT and high-resolution peripheral QCT HR-pQCT pre-operatively and 6 and 12 months post-operatively Aim 2 QCT and HR-pQCT are advanced imaging techniques that have distinct advantages over standard methods but have not yet been applied to this population Finally we will assess body composition changes by anthropometry DXA and QCT and changes in fat-secreted hormones and we will evaluate the relationship between changes in skeletal parameters and changes in body composition and hormones Aim 3 This research is expected to impact the clinical care of gastric bypass patients by helping to shape recommendations about post-operative nutrition BMD screening and potential therapy
As an ancillary study aim Aim 4 we will assess vertebral bone marrow fat pre- and post-operatively in a subgroup of participants and we will evaluate the relationships between change in vertebral bone marrow fat changes in body composition and fat-secreted hormones and changes in skeletal parameters The participants in this subgroup will have the option of undergoing additional knee tissue composition evaluation allowing us to evaluate the relationship between weight loss and change in knee health In order to develop and refine the magnetic resonance MR sequences we will use for Aim 4 we will scan a small group of healthy controls at baseline and after 6 months
We will characterize the effects of gastric bypass on calcium metabolism and the skeleton in a cohort of 80 men and women whose serum 25-hydroxyvitamin D levels are supplemented and maintained at 30 ngmL First we will test the hypothesis that intestinal calcium absorption is impaired following gastric bypass even in the setting of vitamin D sufficiency We will do this by measuring fractional calcium absorption pre-operatively and 6 months post-operatively using dual stable isotopic tracers Aim 1 Then we will test the hypothesis that gastric bypass results in decreased BMD and in structural changes associated with impaired skeletal strength We will do this by performing dual-energy X-ray absorptiometry DXA quantitative computed tomography QCT and high-resolution peripheral QCT HR-pQCT pre-operatively and 6 and 12 months post-operatively Aim 2 QCT and HR-pQCT are advanced imaging techniques that have distinct advantages over standard methods but have not yet been applied to this population Finally we will assess body composition changes by anthropometry DXA and QCT and changes in fat-secreted hormones and we will evaluate the relationship between changes in skeletal parameters and changes in body composition and hormones Aim 3 This research is expected to impact the clinical care of gastric bypass patients by helping to shape recommendations about post-operative nutrition BMD screening and potential therapy
As an ancillary study aim Aim 4 we will assess vertebral bone marrow fat pre- and post-operatively in a subgroup of participants and we will evaluate the relationships between change in vertebral bone marrow fat changes in body composition and fat-secreted hormones and changes in skeletal parameters The participants in this subgroup will have the option of undergoing additional knee tissue composition evaluation allowing us to evaluate the relationship between weight loss and change in knee health In order to develop and refine the magnetic resonance MR sequences we will use for Aim 4 we will scan a small group of healthy controls at baseline and after 6 months
Study Oversight
Has Oversight DMC:
None
Is a FDA Regulated Drug?:
None
Is a FDA Regulated Device?:
None
Is an Unapproved Device?:
None
Is a PPSD?:
None
Is a US Export?:
None
Is an FDA AA801 Violation?:
None
Secondary IDs
| Secondary ID | Type | Domain | Link |
|---|---|---|---|
| R01DK107629 | NIH | None | httpsreporternihgovquickSearchR01DK107629 |