Official websites use. Share sensitive information only on official, secure websites. There is some controversy about the effects of diabetes mellitus on bone remodelling and bone mineral density BMD. The question whether diabetes mellitus is a risk factor for osteopathy i. Increases in osteoporotic fractures were observed only in some studies and no general trends for fracturing of bones were found in diabetics. The factors present in diabetes mellitus, which may influence bone remodelling, will be reviewed.
Bone remodelling comprises the process of bone resorption, which is always followed by bone formation and provides a mechanism for bone self-repair. It represents simultaneous action of bone destroying resorption cells, osteoclasts, and bone forming cells, osteoblasts, which take place on the specific bone surface termed bone remodelling units BRU.
The attraction of osteoclasts to the bone surface is called activation of BRU. The term refers to the event and not to activity of osteoclasts themselves. D increase the frequency of BRU activation i. In healthy subjects, BRU activation occurs every 10 sec and 35 million BRU are active in the whole skeleton at the same time.
During bone resorption the bone mass is being resorbed by osteoclasts. Giant multi-nucleated cells, osteoclasts, excavate the erosion cavity Howership lacunae under themselves in an acid medium by excretion of proteolytic enzymes: cathepsin K, collagenase and phosphatase.
Bone resorption takes from days. Thereafter osteoclasts are replaced by mononuclear cells to smooth off the cavity. Over the next days the layer of cement substance rich in proteoglycans, glycoproteins, but poor in collagen. After the cement substance synthesis is complete, the step named coupling attracts osteoblasts to eroded surface.
