Bone Health After Bariatric Surgery in Patients With Type 2 Diabetes

Inclusion Criteria: * bariatric groups: men and women; 18 to 60 years old; with a BMI \>=35 kg/m2; with type 2 diabetes: use of oral hypoglycemic agents or insulin OR 2 of the following tests confirming type 2 diabetes: HbA1c \>=6.5%; fasting glucose \>=7.0 mM; 2-h glucose post 75g oral glucose tolerance test (OGTT) \>=11.1 mM) (guidelines.diabetes.ca);) or without diabetes: HbA1c \<6.5% AND fasting glucose \<7.0 mM; who are awaiting bariatric surgery. Control group: BMI 25.0 to 29.9 kg/m2 (overweight group); without diabetes or prediabetes: HbA1c \<6.0% AND fasting glucose \<6.1 mM (Diabetes Canada criteria), with a stable weight for the last 3 months. Exclusion Criteria: * bariatric groups: type 1 diabetes; disease (e.g. uncontrolled thyroid disease, malabsorptive or overt inflammatory disorder, metabolic bone disease, creatinine clearance \<60 ml/min) or medication (e.g. glucocorticoids, anti-epileptic drugs, osteoporosis therapy and thiazolidinediones) affecting bone metabolism; BMI\>60 kg/m2; CT scan impossible to perform (e.g. patient too large for the gantry aperture); pregnant women or women who plan to become pregnant during the study or women of childbearing age who do not agree to take an appropriate contraceptive method during the study; history of oesophageal, gastric or digestive surgery; history of bariatric surgery; cancer at risk of recurrence during the study; Prosthesis that could interfere with interpretation of imaging data; Chronic severe condition or illness precluding from participation in the project. Control group: Same criteria plus: \>5% change in weight in the last 3 months; pregnancy or lactation in the last year.