Background: Osteoporotic fractures are a major public health issue. They cause substantial disability, loss of autonomy, morbidity and excess mortality. Diabetes is also associated with increased risk for falls and fractures through a direct impact of elevated blood glucose on the skeleton and on muscles.

Research project overview: The investigators propose a cross-sectional study that will involve 2 research centers in the province of Quebec. The investigators will recruit 20 obese participants, without diabetes, who have not undergone bariatric surgery, for one-time measurements to be compared with baseline measurements (pre-surgery) from participants in the bariatric obese diabetic groups with type II diabetes mellitus from the ongoing study BODI study (NCT03455868). Bone Mineral Density as well as muscle quality, strength and function will be evaluated at a single study visit.

Relevance: This data will permit the evaluation of the bone-muscle unit in patients with obesity with and without diabetes, and assess whether the presence and duration of diabetes impacts further on clinical and functional musculoskeletal outcomes (falls, fractures and mobility and strength) in this population. AGEs, if associated with muscle and bone deterioration, might become an easily accessible biomarker of musculoskeletal health in the clinical setting.

Inclusion Criteria:

A) Diabetic group

• BMI >=35 kg/m2
• Clinical diagnosis of 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)

B) Non-diabetic group:

• BMI >=35 kg/m2
• Normoglycemia (HgbA1c <5.7% and Fasting glucose <5.6 nM)

Exclusion Criteria:

• BMI >60 kg/m2
• Clinical diagnosis of type 1 diabetes
• Disease (e.g. uncontrolled thyroid disease, malabsorptive or overt inflammatory disorder, metabolic bone disease, creatinine clearance <60 ml/min)
• Medication (e.g. gluccocorticoids, anti-epileptic drugs, osteoporosis therapy and thiazolidinediones) affecting bone metabolism
• Pregnancy
• History of oesophageal, gastric, digestive or bariatric surgery
• Prosthesis that could interfere with interpretation of imaging data
• Chronic severe condition or illness precluding from participation in the project.

This is a multi-center, cross-sectional, observational study comprising of two groups of participants with obesity either with or without diabetes (n=20/group). The diabetic groups will include 20 adult men and women with obesity and type 2 diabetes, and the non-diabetic group will consist of 20 age- and sex- matched individuals with obesity and normoglycemia.