Bone health and quality in subjects with morbid obesity - impact of type 2 diabetes and Roux-en-Y gastric bypass

Obesity and type 2 diabetes (T2D) are associated with an increased risk of skeletal fractures despite a normal areal bone mineral density (aBMD) and low bone turnover, possibly due to increased bone marrow adipose tissue (BMAT) and reduced bone material strength. Roux-en-Y gastric bypass surgery (RYGB) is an effective treatment of morbid obesity and T2D. However, the procedure increases fracture rate. In this thesis we found that higher BMI is associated with lower bone material strength and that higher BMAT fraction is associated with poorer glycemic control in subjects with morbid obesity. One year after RYGB, bone material strength im-proved and BMAT fraction decreased on one hand, and bone turnover increased and aBMD decreased, on the other. The changes did not differ in subjects with and without T2D. Ten years after RYGB, the prevalence of osteoporosis and low-energy fractures was high. Consequently this thesis contributes to the understanding of the relationship between diabetes, obesity and bone health, and the changes after RYGB. Our long-term findings suggest assessment of bone heath should be included in future bari-atric guidelines