Bone density in patients with type 2 diabetes and its pathophysiology

Objective To investigate into the change in bone mineral density (BMD) and its pathophysiology in patients with type 2 diabetes mellitus (DM). Methods BMD of proximal femur and AP spine and several metabolic parameters in 93 type 2 diabetes mellitus patients, were measured, and were compared with an age and BMI matched control group. Results ①type 2 diabetes mellitus patients had higher BMD at femoral neck、troch、Ward's triangle, L 4 and L 2 L 4 and had lower BMD at L 2 as compared with normal controls. ②Over all areas studied except L 2, DM A group had higher BMD than normal controls, DM B group had lower BMD than DM A group (DM course less than 5 years). At femoral neck,troch,L 3,L 4 and L 2 L 4 DM B group (DM course at least 5 years) had lower BMD than normal controls. At L 2, DM A group had lower BMD than normal controls, and DM B group had higher BMD than DM A group. ③In type 2 diabetes mellitus group, the duration of type 2 diabetes mellitus correlated negatively with BMD at femoral neck, troch and Ward's triangle (P0.05). ④In type 2 diabetes mellitus patients serum Ca and P were normal. Serum parathyroid hormone was significantly higher than that of the controls (P0.05). Serum bone glaprotein was significantly lower than that of the controls (P0.05). Urine Crosslaps/Cr was higher than that of the controls, but without statistical significance. Conclusion The changes in BMD of above areas in type 2 diabetes mellitus patients are different and BMD of proximal femur correlates negatively with the duration of type 2 diabetes mellitus. The characteristics of bone change in type2diabetesmellituspatientshavehigh bone absorption rate and low bone turnover rate. Secondary hyperparathyroidism may probably contribute to the bone change.