How many of you would connect diabetes mellitus with a higher rate of bone fractures? Most likely, you wouldn’t put a link between these two medical issues. Yet, there is a higher fracture risk for diabetic patients.
The question of how diabetes weakens our skeleton is not fully understood. Many factors are at play, so an increasing number of scientists and physicians focus on this research topic. Because if we know how this disease affects bone tissue, we will be able to better and especially in time, identify at-risk patients and prevent fractures’ frequency.
One of the possibilities of studying bones is to make the structure visible. We can simply imagine it as a wood structure. On the tree trunk’s cross-section, we see annual rings, and in them, you can read like in a book, they can tell us how old the tree was or if the tree was ever sick.
The bone structure is, in a way, comparable to the wooden structure. The basic building block of bone is the osteon, and it looks just like a cross-section of a tree. We have many osteons in bone tissue. The number, size, or age of osteons provides valuable information about bone’s basic structure and mechanical properties. Osteons size is in the range of 100-200 µm, so it is possible to observe them under a conventional light microscope.
But to find the cause of bone structure decay, we need to go deeper. If we focus on a single osteon, then it is formed by a complex of concentric lamellae and imagine one lamella as the only annual ring in wood. The lamellae contain osteocytes that serve as mechanosensors of bone and regulate bone remodelling. In diabetic bone is the remodelling process often imbalanced, which leads to weakening the bones. That is why we examine osteocytes and their interconnection using light and electron microscopy.
But now, let’s focus on the lamella itself, which consists of collagen fibres. In between collagen fibres are hydroxyapatite crystals – this is the source of calcium in our bones. Collagen gives our bones elasticity, and hydroxyapatite gives us strength. These structures are already in the nanometre range, so it is not so easy to observe them. However, this is the level where diabetes starts to disrupt bone structure and function. A higher concentration of glucose in the blood is changing collagen fibres, causing lower flexibility. We need more advanced technologies such as electron microscopy or spectral methods to study these structural changes in detail.
Therefore, my work aims to describe all these changes in the diabetes-affected bone structure or, as I like to call “sugared bone” from the macroscopical perspective of osteons to individual collagen fibres. Because that is the only way to understand how the disease works and help improve the diagnosis and prevention of fractures in patients with diabetes.