Diabetoporosity—diabetes and the bone
Osteoporosis and diabetes mellitus type 2 (T2DM) are frequently coinciding in elderly patients, increasing with age. The disease is associated with a higher fracture risk despite normal to high planar bone mineral density (BMD) as measured by dual energy bone densitometry (DXA) in these individuals. As BMD measurements do not identify T2DM patients at risk for bone fractures, this coincidence has not been recognized for a long time, though higher mortality and the risk of a delayed wound healing have been found in T2DM patients with major fractures. In patients with diabetes mellitus type 1 (T1DM) fracture risk is even higher, with an up to 12-fold risk as compared to patients with normal glucose metabolism. These patients might be affected from early childhood on, with worse fracture outcomes depending on their glucose control. Pathophysiological conditions that might contribute to the increased fracture risk in both T1DM and T2DM include decreased skeletal quality and properties, aggravated by comorbidities such as macro- and microvascular complications, and chronic inflammation, but there are many open questions to resolve. As specific diagnostic approaches are urgently required, several attempts have been made by new imaging technologies, namely trabecular bone score (TBS), high resolution peripheral quantitative computed tomography (HRpQCT), bone biopsies, histomorphometry and microindentation. New biomarkers of diabetoporosity have been addressed. The complex interaction of these new biomarkers is illustrated by several articles within this issue. We report on the current knowledge in pathophysiology, diagnostics and management of bone in diabetes mellitus. Given the increasing numbers of T2DM and osteoporosis patients worldwide—with a current number of about 415 million T2DM patients, a growing community of T1DM patients and about 9 million osteoporotic fractures annually in 200 million women and probably 120 million men—this is in fact an important problem for future health care.