CLINICAL IMPLICATIONS Does diabetes really cause bone disease?

There are no two more complex chronic conditions than diabetes and osteoporosis. Diabetes is a generic term and is commonly divided into type 1, an autoimmune, insulin-deficiency disease, and type 2, which is hallmarked by insulin resistance and initially at least by high insulin levels. The latter condition may afflict half a billion persons world-wide and is associated with relative obesity. All diabetics are at risk of developing peripheral neuropathy so that fracture risk from falls and neuropathic bone disease is substantially increased. Thus, there are numerous confounders in any relationship between diabetes and bone disease. In this issue, Freude et al. [1] report that hyperinsuline-mia reduces osteoblast activity in vitro via upregulation of transforming growth factor-beta (TGF-β). They incubated human osteoblasts under 8- and 25-mM glucose conditions