Bone Marrow Fat and Bariatric Surgery-Mediated Bone Loss

Study Overview
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Brief Summary
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Results are inconsistent and further studies are needed to better understand the impact of bariatric surgery on the bone-BMA relationship depending on the type of bariatric surgery: RYGB vs. SG. Future studies are also needed to define the molecular mediators of bone loss and BMA changes. Several molecular mediators have been considered including gut hormones, adipokines, gonadal hormones and more recently G-CSF. However, the evidence to support any of these alone or in combination as primary mechanisms of bone loss is scant. The study will be to explore potential changes in BMA after bariatric surgery and search for possible associated factors. Specifically, we want to investigate if such changes in BMFF differed in participants among different surgical types (RYGB vs. SG) and diabetic status. Secondly, we want to explore factors associated with BMFF changes including metabolic homeostasis (glycemic control and blood lipid levels), adipokines (leptin and adiponectin), calciotropic hormones (Ca++, PTH…), body composition parameters and bone markers (cross-laps, P1NP and sclerostin). We hypothesize that the BMFF would particularly decrease after RYGB compared to SG and that participants with T2D would have a larger decrease in BMFF than participants without T2D.

Official Title
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Bone Marrow Fat and Bariatric Surgery-Mediated Bone Loss

Conditions
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Bariatric Surgery in Postmenopausal Women

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Postmenopausal women (defined as last menses >12 months) Obesity with a BMI ≥ 35 kg/m², Patients with an indication for bariatric surgery with two surgical techniques, RYGB and SG, but who have never had a bariatric surgery procedure previously, Enrollment will be stratified for each surgical techniques, RYGB and SG, by preoperative diabetes status, defined by having HbA1c >6.5% or a prior physician's diagnosis of diabetes plus use of an antidiabetic medication. Patients who have signed the informed consent. Exclusion Criteria: women who were pre- and perimenopausal and men in order to minimize sex hormone and BMA changes unrelated to the surgical procedure. women who used medications known to impact bone metabolism or BMA, including bisphosphonates, teriparatide, denosumab, hormone replacement therapy (HRT) and oral glucocorticoids (>5mg prednisone equivalent daily for>10 days in the last 3 months. Other exclusion criteria included prior bariatric surgery, estimated glomerular filtration rate <30 mL/min, any contraindication to magnetic resonance imagery (MRI).

Ages Eligible for Study
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Minimum Age: 45 Years
Maximum Age: 70 Years

Sexes Eligible for Study
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Female

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Obese postmenopausal women who will undergo RYGB<br> | |
| Obese postmenopausal women who will undergo SG<br> | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Variation in bone marrow fat fraction (BMFF) in % |  | 12 months |