Bone fragility in male glucocorticoid-induced osteoporosis is not defined by bone mineral density

Eighty-seven male Japanese subjects taking prednisolone a parts per thousand yen5 mg for more than 6 months and 132 age- and body mass index (BMI)-matched control subjects were examined. Multiple regression analysis adjusted for age and BMI showed that spinal bone mineral density (BMD) in the prednisolone group was not associated with prevalent vertebral fractures (VFs). Glucocorticoid (GC) treatment is known to increase the risk for bone fractures. However, the association between VFs and BMD in GC-treated male patients remains unclear. Eighty-seven male subjects taking prednisolone a parts per thousand yen5 mg for more than 6 months and 132 age- and BMI-matched control subjects were examined using lateral thoracic and lumbar spine radiographs and spine dual energy X-ray absorptiometry. The presence of GC use was an independent risk factor for VFs adjusted for age and BMI (odds ratio 10.93, P < 0.001). By receiver operating characteristic analysis, the absolute BMD values for detecting VFs were higher and the sensitivity and specificity were lower in the GC group than in the control group (0.936 vs 0.825 g/cm(2) and 53.5% vs 74.0%, respectively). Multiple regression analysis adjusted for age and BMI showed that spinal BMD in the GC group was not associated with prevalent VFs, even after adding current and past maximum GC doses as independent variables. These results show that lumbar BMD values are not associated with prevalent VFs in GC-treated male patients, suggesting that bone fragility in male GC users is affected by bone quality rather than by BMD.