Bisphosphonate Use to Mitigate Bone Loss Secondary to Bariatric Surgery

The purpose of this research study is to see whether receiving a bisphosphonate medication called risedronate can reduce bone and muscle loss following bariatric surgery. Participation will involve up to 6 study visits and last about 1 year. Risedronate is a medication that prevents bone breakdown and has been approved by the US Food and Drug Administration (FDA) for the prevention and treatment of osteoporosis in older men and women. However, risedronate has not been approved for the prevention of bone and muscle loss following vertical sleeve gastrectomy. Participation in this study will involve completing two visits before beginning the intervention. Participants who qualify will be scheduled to begin the intervention program which will involve taking 6 monthly doses of a risedronate or placebo pill. Participants will then receive monthly contacts by study staff during this time to remind participants to take the intervention pill and ask about any adverse events. After the completion of intervention period, participants will complete up to 4 follow up study visits at 6 months (2 visits) and at 12 months (2 visits).

The main objective of the proposed study is to definitively test whether risedronate use can effectively counter sleeve gastrectomy (SG) associated bone loss. To do this, we propose to randomize 120 middle-aged and older (≥40 years) SG patients to six months of risedronate or placebo treatment, with musculoskeletal outcomes assessed at baseline, six, and 12 months. Due to its robust change following SG and clinical utility in predicting fracture, our primary outcome is change in total hip areal (a) bone mineral density (BMD) measured by dual energy x-ray absorptiometry (DXA). This will be complemented by DXA-acquired aBMD assessment at other skeletal sites and appendicular lean mass, as well as quantitative computed tomography (QCT) derived changes in bone (volumetric BMD, cortical thickness, and strength) and muscle (cross sectional area, fat infiltration) at the hip and spine - allowing for novel assessment of intervention effectiveness on several state of the art bioimaging metrics. Select measures of physical function (fast 400-m walk, stair climb) are also included as proxies of fall risk. Thus, the study team aims to: Aim 1: Determine the effect of risedronate compared to placebo on 12-month change in total hip aBMD following SG. Aim 2: Determine the effects of risedronate compared to placebo on 12-month change in DXA-acquired aBMD at additional skeletal sites and appendicular lean mass; QCT-derived measures of bone and muscle at the hip and spine following SG; and select physical function tasks. Aim 3: Investigate the impact of treatment group assignment on biomarkers of bone turnover and bone-muscle crosstalk to elucidate mechanisms underlying change in DXA and QCT-derived metrics.

Fast-paced gait speed will be assessed using the fast 400 meter walk test. Participants will be asked to walk 10 laps of a 40 meter course (20 meters out and 20 meters back) as fast as possible and are given a maximum of 15 minutes to complete the test.

Stair climbing ability will be assessed by using the participant's fastest time achieved to climb 12 steps in two trials. Both tests are sensitive to intensive weight loss and predictive of fall risk.

Inclusion Criteria: Subjects who have had sleeve gastrectomy Willing to provide informed consent Agree to all study procedures and assessments. Exclusion Criteria: Weight greater than 450 lbs Regular use of growth hormones, oral steroids, or prescription osteoporosis medications; Known allergies to bisphosphonates Unstable gastric reflux requiring two or more additional doses per month of anti-reflux medication. Current participation in other research study Unable to provide own transportation to study visits Unable to position on scanner independently.