Bone density reduction in various measurement sites in men and women with osteoporotic fractures of spine and hip: The European quantitation of osteoporosis study

We have measured bone mineral density (BMD) using dual X-ray absorptiometry (DXA) of the spine and hip, spinal quantitative computed tomography (QCTsp i), and peripheral radial quantitative computed tomography (pQCTrad) in 334 spine and 51 hip fracture patients. The standardized hip and spine BMD for each patient was calculated and compared with the combined reference range s published previously, each densitometer having been cross-calibrated with the prototype European Spine Phantom (ESPp) or the European Forearm Phanto m (EFP). Male and female fracture cases had similar BMD values after adjusting for b ody size, where appropriate. This suggests that the relationship between bo ne density (mass per unit volume) and fracture risk is similar between men and women. However, compared with age-matched controls, mean decreases in B MD ranged from 0.78 SD units (women with hip fracture, DXAspi) to 2.57 SD u nits (men with spine fractures, QCTspi). The proportion of spine and hip fracture patients falling below the cutoff for osteoporosis (T-score <-2.5 SD) proposed by the World Health Organizati on (WHO) study group varied according to different BMD measurement procedur es (range 18-94%). This finding suggests that the WHO definition requires d ifferent thresholds when used with non-DXA BMD measurement techniques. Receiver operator characteristic (ROC) analysis was used to compare measure ment techniques for their ability to discriminate between cases and control s. Among DXA sites, the proximal femur was preferred when evaluating genera lized bone loss, particularly in elderly people. An additional spinal BMD m easurement may add clinical value if spine fracture risk assessment has a h igh priority. Both axial and peripheral QCT techniques performed comparably to DXA in spinal osteoporosis, so investigators and clinicians may use any of the three technologies with similar degrees of confidence for the diagn osis of generalized or site-specific bone loss providing straightforward cl inical guidelines are followed.