Evaluation of bone architecture, bone marrow adipose tissue and intramuscular lipids in type 2 diabetes mellitus

Author(s)

Iana Mizumukai de Araujo

• Document type: Doctoral Thesis
• Press: Ribeirão Preto.
• Institution: Universidade de São Paulo (USP). Faculdade de Medicina de Ribeirão Preto (PCARP/BC)
• Defense date: 2019-03-13

Examining board members

Francisco Jose Albuquerque de Paula; Anderson Marliere Navarro; Rosa Maria Rodrigues Pereira

• Advisor: Francisco Jose Albuquerque de Paula

Abstract

Type 2 diabetes is a high prevalence disease and its complications go beyond the cardiovascular diseases. Bone fragility was recently added to the list of the type 2 diabetes complications. Paradoxically, in type 2 diabetes, the bone mass is normal or elevated in comparison to the normoglycemic subjects. Thus, it is necessary to explore other tools to improve the bone evaluation in type 2 diabetes. The aim of this study was to characterize the trabecular bone phenotype in patients with type 2 diabetes and to evaluate the influence of bone marrow adipose tissue, accumulation of muscle fat and insulin resistance in bone mass. Lumbar spine and proximal tibia magnetic resonance spectroscopy was used to quantify bone marrow adipose tissue, 3D imaging by Magnetic Resonance of proximal tibia was used to quantify the trabeculae. Bone densitometry was performed to quantify the bone mineral density and also the body composition. Trabecular bone score (TBS) was measure in lumbar spine. Biochemical tests were carried out to evaluate the potential modulators of bone metabolism. Three groups were evaluated: control, obese and type 2 diabetic. The results show that diabetic individuals have no bone mass impairment and no alterations in the proximal tibia trabeculae. No alteration was observed in the the bone marrow adipose tissue of and there was no relationship of this site of fat storage with the mass. The results showed that fat mass and intramuscular lipids had a negative correlation with TBS, and lean mass showed a positive correlation with bone mineral density. As well as we know, this is the first study in the literature in which the bone structure in type 2 diabetes mellitus was evaluated by magnetic resonance imaging. These data reaffirm that there are no quantitative structural changes in bone in this condition, indicating that the bone fragility observed in DM2 populational studies is probably due to impairment in bone quality. CTX, osteocalcin and adiponectin seems to have an important role in determining in the trabeculae (AU)

• FAPESP's process: 16/18574-1 - The use of magnetic resonance imaging in the quantitative study of bone microarchitecture and its relatioship with the accumulation of muscle and bone marrow adipose tissue in DM2
• Grantee: Iana Mizumukai de Araujo
• Support Opportunities: Scholarships in Brazil - Doctorate