The public defence will be held as a video conference over Zoom.
The digital defence will follow regular procedure as far as possible, hence it will be open to the public and the audience can ask ex auditorio questions when invited to do so.
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Digital trial lecture - time and place
Adjudication committee
- First opponent: Professor Bjørn Richelsen, Aarhus University, Denmark
- Second opponent: Professor Erik Näslund, Karolinska Institutet, Stockholm, Sweden
- Third member and chair of the evaluation committee: Associate Professor Ingrid Nermoen, Institute of Clinical Medicine, University of Oslo
Chair of defence
Professor emeritus Kristian Folkvord Hanssen, Institute of Clinical Medicine, University of Oslo
Principal supervisor
MD, PhD Erik Fink Eriksen, Institute of Clinical Medicine, University of Oslo
Summary
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 seems to induce harmful effects on the skeleton
This thesis aimed to evaluate changes in factors influencing bone health and quality; bone material strength, aBMD, bone turnover markers, and BMAT in a population with morbid obesity undergoing RYGB and to assess whether these changes differed in participants with and without T2D. Secondly, the prevalence of osteoporosis and low-energy fractures in a defined patient cohort 10 years after RYGB was evaluated.
In a population with morbid obesity, higher BMI was inversely associated with bone material strength and higher BMAT fraction was associated with poorer glycemic control. As suspected aBMD decreased and bone turnover increased after RYGB, but surprisingly bone material strength improved and BMAT fraction decreased. These changes did not appear to differ between subjects with and without T2D. However, improved glucose control in T2D subjects after RYGB was associated with improved bone material strength.
Ten years after RYGB, the prevalence of osteoporosis and low-energy fractures was high. The study also found that subjects with hypothyroidism prior to RYGB, or subjects with secondary hyperparathyroidism, older age, postmenopausal status or higher bone turnover 10 years after RYGB had higher odds of a low aBMD.
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 bariatric guidelines.
Additional information
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