Evaluation of Expected Bone Loss After Bariatric Surgery, Possible Prevention of Bone Loss After Surgery by Calcium and Vitamin D Supplementation
Conditions
Brief summary
Bariatric surgery leads to rapid weight loss in female and male patients. Less data are available about its impact on bone metabolism. The aim of this study is the investigation of changes in bone mineral density,bone histomorphometric changes, serum bone turnover markers and changes in body fat and muscle composition in patients after laparoscopic gastric bypass surgery.
Detailed description
Obese female and male adult patients eligible for laparoscopic gastric bypass surgery according to the national Austrian guidelines will be included in this study upon request and after patient approval. Baseline data collection and quarterly follow up visits are planned to investigate the changes in bone mineral density and body composition measured by dual energy X-ray absorptiometry as well as the evaluation of serum bone turnover markers of bone formation and resorption. After surgery subjects will be randomized into two groups: Daily oral calcium (500mg) and weekly vitamin D3 supplementation (16.000 IU calciferol)or no supplementation of calcium and calciferol. A sub-study (approximately 15% of study population) with transiliac bone biopsies will also be performed to investigate histomorphometric and histologic changes in bone (biopsy baseline and after 24 months). The planned duration of the study is 24 months for each subject. Serum bone turnover markers will be collected every 3 months, dual energy X-ray absorptiometry measurements will be performed every 6 months.
Interventions
DRUGCalciferol, calcium carbonate
Sponsors
Medical University of Vienna
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
18 Years to 65 Years
Healthy volunteers
No
Inclusion criteria
* body mass index \>35 * female and male patients * age 18 - 65 years * eligible for laparoscopic gastric bypass surgery according to the Austrian national guidelines
Exclusion criteria
* any history of malignancy except basalioma * any prior antiresorptive treatment * any prior calcium or vitamin D supplementation * any secondary disease affecting bone metabolism
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Evaluation of bone mineral density changes in obese patients after laparoscopic bariatric surgery | Evaluation every 6 months for 24 months | Dual energy X-ray absorptiometry (DXA) measurements of bone mineral density at lumbar spine, hip, calcaneus and total body will be performed at baseline and every six months for a period of 24 months. Differences will be evaluated on the outcome with/without daily calcium (500mg) and weekly vitamin D (16.000 IU calciferol) supplementation |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Evaluation of changes of serum bone turnover markers in obese patients after laparoscopic bariatric surgery | Evaluation every 3 months for 24 months | Fasting serum markers of bone formation and bone resorption will be evaluated: Calcium, 25-OH-vitamin D3, intact parathyroid hormone, beta-crosslaps, type-1-procollagen, bone specific alkaline phosphatase, osteocalcin, sclerostin, osteoprotegerin, cathepsin-K, fibroblast factor 23, lipoprotein A, dickkopf 1 Differences will be evaluated on the outcome with/without daily calcium (500mg) and weekly vitamin D (16.000 IU calciferol) supplementation |
Other
| Measure | Time frame | Description |
|---|---|---|
| Evaluation of histomorphometric and histologic changes in obese patients after laparoscopic bariatric surgery | baseline and after 24 months | Transiliac bone biopsies will be performed in a approximately 15% of patients at baseline and after 24 months. The following parameters will be measured: bone volume (BV/TV), bone surface (BS/BV), osteoblast surface (OS/BS), trabecular number (TbN), trabecular thickness (TbTh, trabecular separation (Tb.sp), mineralized surface (MS/BS), mineral apposition rate (MAR) Differences will be evaluated on the outcome with/without daily calcium (500mg) and weekly vitamin D (16.000 IU colecalciferol) supplementation |
Countries
Austria
Outcome results
None listed