Overview

Background: Bariatric surgery is gaining in popularity. While it's health benefits are undisputed, the older malabsorptive bariatric procedures (Roux-in-Y gastric bypass - RYGB and biliopancreatic diversion - BPD) are associated with an increased risk of fractures and falls as early as 3-5 years after surgery. Sleeve gastrectomy - SG is now the most performed bariatric procedure. Although SG does not cause malabsorption, it is predicted to result in bone and muscle loss via weight loss and weight loss-independent mechanisms. Primary aim: to compare the changes in spine volumetric bone mineral density (vBMD) by quantitative computed tomography (QCT) and muscle mass at mid-femur by computed tomography (CT) at 3 years in the 3 groups of: 1) men; 2) premenopausal women; 3) postmenopausal women after SG versus their respective non-surgical peers who did not undergo SG in the 3-year period following recruitment. Secondary aims: to compare the changes in vBMD by QCT at skeletal sites other than the spine and in areal bone mineral density (aBMD) by dual-energy X-ray absorptiometry (DXA), whole-body muscle mass by DXA, muscle quality by CT at mid-femur and muscle strength as well as in selected physical performance and capacity tests shown to predict falls and fractures between 0-1 and 1-3 years after SG in the same 3 groups after SG vs. in the respective non-surgical groups.

Eligibility

Inclusion Criteria:

• Men and women aged >18 years;
• Awaiting SG for the bariatric group or meeting the criteria for SG but not undergoing surgery for the non-surgical group.
• Menopause: defined as the absence of menses for a year and a serum follicular-stimulating hormone (FSH) >40 UI/L.
• Women taking oral contraceptive pills or hormone replacement therapy
• Patients with type 2 diabetes.

Exclusion Criteria:

• Type 1 diabetes;
• Disease (e.g., uncontrolled thyroid disease, Malabsorptive or overt inflammatory disorder)
• Metabolic bone disease other than osteoporosis or type 2 diabetes,
• Creatinine clearance <30 ml/min) or medication (e.g., glucocorticoids, anti-epileptic drugs, osteoporosis therapy, thiazolidinediones) affecting bone metabolism;
• Weight >204 kg (DXA weight limit) or BMI >60 kg/m2 (upper limit to allow for QCT examination);
• Current or planned pregnancy during follow-up; breast-feeding.