Bone Imaging with Quantitative CT and MRI
Quantitative CT (QCT) and MRI enable independent measurements of trabecular and cortical BMD as well as bone structure and derived measures of bone strength. QCT and MRI produce tomographic images of the bone which provide 3D images of bone geometry which can be used to measure cortical bone dimensions.
Circulating miRNAs as Biomarkers of Osteoporosis
Circulating miRNAs are remarkably stable analytes that can be measured using qPCR, but their analysis faces several pre-analytical as well as analytical challenges. There is accumulating evidence that miRNAs play an essential role in the regulation of bone homeostasis, and specific changes in miRNA transcription levels or miRNA secretory levels have been linked to the development and progression of certain bone diseases. Results from circulating miRNAs analysis in patients with osteopenia, osteoporosis and fragility fractures have been reported. By comparing these findings to studies on circulating miRNAs in cellular senescence and aging or muscle physiology and sarcopenia, several overlaps were observed. This suggests that signatures observed during osteoporosis might not be specific to the pathophysiology in bone, but rather integrate information from several tissue types (Hackl et al. 2016). Further work is in progress to validate circulating miRNAs as robust diagnostic tools for bone diseases in clinical research, clinical routine and in personalized medicine. Another study in postmenopausal women found that miR-382-3p significantly enhanced osteogenic differentiation, while miR-550a-5p inhibited this process; both impaired adipogenic differentiation, while miR-188-3p did not exert an effect on adipogenesis (Heilmeier et al. 2016). None of the miRNAs affected cell proliferation significantly. These data suggest for the first time that miRNAs are linked to fragility fractures in type 2 diabetic postmenopausal women and should be further investigated for their diagnostic potential and their detailed function in diabetic bone. osteomiR™ (TAmiRNA GmbH) is a signature of serum miRNAs that is associated with bone quality and is intended to assess the risk of a first fracture in postmenopausal and type-2 diabetic women.