Effects of Sleeve Gastrectomy on Calcium Metabolism and the Skeleton
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ClinicalTrials.gov Identifier: NCT02778490
Recruitment Status :
Active, not recruiting
First Posted : May 20, 2016
Last Update Posted : January 18, 2020
San Francisco Veterans Affairs Medical Center
University of California, San Francisco
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Information provided by (Responsible Party):
Anne Schafer, San Francisco Veterans Affairs Medical Center
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).
Change in intestinal fractional calcium absorption [ Time Frame: 6 months ]
The investigators will determine whether there is a change in intestinal calcium absorption, assessed using the dual stable isotopes Ca-43 and Ca-44 in the setting of robust vitamin D status, following sleeve gastrectomy.
Secondary Outcome Measures :
Percentage change in spinal volumetric bone mineral density [ Time Frame: 12 months ]
The investigators will define the effects of sleeve gastrectomy on spinal volumetric bone mineral density, assessed by quantitative computed tomography (QCT).
Percentage change in volumetric bone mineral density at the distal tibia [ Time Frame: 12 months ]
The investigators will define the effects of sleeve gastrectomy on total volumetric bone mineral density at the distal tibia, assessed by high-resolution peripheral quantitative computed tomography (HR-pQCT).
Percentage change in cortical porosity at the distal tibia [ Time Frame: 12 months ]
The investigators will define the effects of sleeve gastrectomy on cortical porosity at the distal tibia, assessed by high-resolution peripheral quantitative computed tomography (HR-pQCT).
Other Outcome Measures:
Percentage change in spinal volumetric bone mineral density by QCT [ Time Frame: 6 months ]
Percentage change in volumetric bone mineral density at the distal tibia by HR-pQCT [ Time Frame: 6 months ]
Percentage change in cortical porosity at the distal tibia by HR-pQCT [ Time Frame: 6 months ]
Percentage changes in cortical and trabecular volumetric bone mineral density and microstructural parameters at the radius and tibia by HR-pQCT [ Time Frame: 6 months and 12 months ]
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Layout table for eligibility information
Ages Eligible for Study:
25 Years to 70 Years (Adult, Older Adult)
Sexes Eligible for Study:
Accepts Healthy Volunteers:
Obese men and women undergoing sleeve gastrectomy surgery
Women and men 25 to 70 years old scheduled to undergo sleeve gastrectomy
Please note that the investigators are unable to provide sleeve gastrectomy; rather, potential participants must already be planning the procedure with their surgeons.
Perimenopausal women, defined as last menses >3 months but < 5 years ago
Known intestinal malabsorption (e.g., celiac disease, short gut syndrome, prior intestinal surgery)
Prior bariatric surgery
Use of medications known to impact bone and mineral metabolism, including use of a bisphosphonate or teriparatide in the last year or for >12 months ever; current calcitonin; prednisone >5 mg daily or the equivalent glucocorticoid for >10 days in the last 3 months; a current thiazolidinedione (TZD); an aromatase inhibitor; androgen deprivation therapy; an antiepileptic agent known to alter hepatic vitamin D clearance; or thyroid hormone replacement with current thyroid stimulating hormone < 0.1 milli-international units per liter
Disease known to affect bone (e.g., primary hyperparathyroidism, Pagets disease, clinically significant liver disease)