Comparison of bone mineral density and bone histomorphometry in postmenopausal type 2 diabetic patients

The definition of osteoporosis evolves as our knowledge on osteoporosis increases. It was once defined as a decrease in bone mass that would reduce mechanical capacity but recently it is accepted as a decrease in both bone mineral density (BMD) and bone quality. Thus, the gold standard method of measurement of BMD with dual X-Ray absorptiometry (DXA) is insufficient to fulfill this definition.In this study, we aimed to compare the histomorphometric measurements that show bone mass, such as bone volume ratio and trabecular thickness, of postmenopausal patients with diabetes mellitus with controls without diabetes and investigate the relationship between these parameters and BMD measurements and whether in patients with fractures, bone-related or non-related factors play a role in the development of those fractures.16 diabetic and 9 non-diabetic postmenopausal females who had been hospitalized for osteoporosis related hip fracture operation or any fracture-unrelated hip operation whether or not in association to osteoporosis, had been included in the study. BMD measurements had been done with DXA. FPG, A1C, calcium, phosphorus, PTH, 25 OH Vitamin D, IGF-1, free T4, TSH and E2 levels had been measured. Trabecular thickness and bone volume ratio had been calculated from bone biopsy specimen obtained from iliac crest.The results show that BMD measurements obtained from lumbar region of diabetic patients were significantly higher than non-diabetic controls. While bone volume ratio and trabecular thickness of all patients showed significant correlation with hip region BMD, they were not correlated with lumbar region BMD measurements. BMD measurements from all regions and histomorphometric parameters showed a negative correlation with age and a positive correlation with body weight and body mass index (BMI).When all patients with fracture (diabetic and non diabetic) were analyzed; it was found that older age was a negative and BMI was a positive independent factor and diabetic patients with fractures had higher bone mass. Current diagnostic methods used to determine osteoporosis are insufficient in determining fracture risk in the diabetic population. New methods showing bone quality and strength are needed but routine determination of these parameters is unpractical. Thus the diagnosis of osteoporosis and fracture risk could be better determined by modification of the present diagnostic criteria.