[Bone loss in type 2 diabetes mellitus--diabetic osteopenia]

Loss of bone mineral content has been recognized as one of the chronic complications of type 2 diabetes mellitus, although its mechanism is not fully documented. A negative calcium balance due to both enhanced urinary calcium excretion and decreased intestinal calcium absorption has been occurred because of alteration of vitamin D metabolism and/or decreased parathyroid function. From the view point of bone cell metabolism, osteoblastic bone formation is suppressed by alternation of vitamin D metabolism, hypoparathyroidism, chronic hyperglycemia and insufficient insulin action. On the other hand, osteoclastic bone resorption is rather enhanced. The functional bone uncoupling system between osteoblast and osteoclast in type 2 diabetes mellitus could result in loss of bone density.