Bone metabolism in type 2 diabetes mellitus

Several conditions have been described to cause osteoporosis, including diabetes mellitus. While the relationship between type 1 diabetes and osteopenia is well documented in the literature, data on the presence of this complication in type 2 diabetes have not been well established. We studied a population composed of 66 post-menopausal women with type 2 diabetes and a control population. We examined bone mineral density with the dual-energy X-ray absorptiometry (DXA) technique at the lumbar and femoral levels and, in a subgroup of patients, we also measured the levels of markers of bone remodelling. We found significantly higher levels of bone mineral density at the femoral (but not lumbar) level in the diabetic subjects compared with the control population in all the examined subregions, except Ward's triangle. Moreover, we found higher levels of some markers of bone resorption (urinary calcium and hydroxyproline, telopeptide) in the patients with diabetes, while urinary crosslinks were higher in the controls. On the basis of these results, we suggest that osteoporosis cannot be considered a complication of type 2 diabetes and that, from a metabolic point of view, bone resorption is greater in diabetic patients than in normal subjects, as suggested by the high levels of most of the markers of osteoclastic activity.