Cut-off Values Determined for Vertebral Fracture by Peripheral Quantitative Computed Tomography in Japanese Women

Abstract

In spite of the benefits of bone mass measurement by dual-energy X-ray absorptiometry (DXA), the use of DXA has limitations. It is unable to assess a true bone density, and cannot discriminate between the trabecular and cortical bone compartments. Ultradistal radius bone density was measured using peripheral quantitative computed tomography (pQCT) to determine reference values for total bone density (BD), trabecular bone density (TBD), polar strength strain index (pSSI), total bone mineral content (BC), trabecular bone mineral content (TBC), cortical bone density (CBD), cortical bone mineral content (CBC) and polar cross-sectional moment of inertia (pCSMI) in the Japanese female population, and to ascertain the cut-off values of the measured indicators that could most efficiently discriminate osteoporotic subjects with vertebral fractures. A total of 5266 healthy Japanese women aged 20-89 years were included in this study to determine Japanese reference values. Additionally, 621 who had undergone radiographic examination of the thoracic and lumbar spine at the time of pQCT measurement were selected to determine the cut-off values of BD, TBD, pSSI and other indicators for vertebral fractures. All the healthy subjects were divided into 5 year age groups. The BD showed nonsignificant changes from the 20-24 year age group to the 45-49 year age group, and fell significantly thereafter. The TBD maintained a plateau until the 40-44 year group, which corresponds to the young adult mean (YAM) values of the lumbar spine, femoral neck and radius BMDs measured using DXA. The TBD decreased significantly thereafter. The pSSI did not change significantly from the 20-24 year age group to the 45-49 year age group, and decreased slightly in the 50-54 year age group and markedly after 55-59 years. The cut-off values for the discrimination of vertebral fractures were obtained by the calculation of sensitivities, specificities and the area under the curves obtained using age-adjusted receiver operating characteristics (ROC) analysis. Odds ratios and 95% confidence limits (CL) were calculated using age-adjusted logistic analysis. The cut-off values for vertebral fractures, the area under the ROC curves (AUC) and odds ratios were 270.1 mg/cm3 (-2.2 SD, 66.6% of YAM), 0.689+/-0.025, 2.10 (1.63, 2.70) for BD, 104.8 mg/cm3 (-2.2 SD, 53.5% of YAM), 0.699+/-0.023, 2.17 (1.69, 2.77) for TBD and 192.8 mm3 (-1.9 SD, 59.8% of YAM), 0.631+/-0.028, 1.72 (1.34, 2.21) for pSSI, respectively. These findings suggest that ultradistal radius BMD measured using pQCT can be used to discriminate women with vertebral fractures.

Novel ultrasonic bone densitometry based on two longitudinal waves: significant correlation with pQCT measurement values and age-related changes in trabecular bone density, cortical thickness, and elastic modulus of trabecular bone in a normal Japanese population

“…Similar findings have been reported in Japanese women using a pQCT system, showing the peak TBD at 25-29 years and a plateau of TBD from 20-24 to 40-44 years [28]. The difference in the pattern of decrease in TBD after the plateau between men and women seen in our study is probably related to the wellknown estrogen effect on maintaining bone mass in women [32,33].…”

“…As mentioned in Materials and methods, the measurement site for the LD-100 system (the nearest point to the distal 5.5% point of the radius for both TBD and CoTh) was chosen to select a perpendicular incidence site for the ultrasonic beam and to avoid interference waves overlapping with the transmitted signal. On the other hand, the measurement site used for the pQCT system is well accepted as 4% of the forearm length proximal to the distal end of the radius for TBD and the mid-radial 20% site for CoTh, adopting the area of high mineral content and trabecular bone percentage for the former and the area with a relatively round shape of the cross-section of the radius, permitting the application of the circular ring model, for the latter [25,[27][28][29][30][31]. In the present study, a highly significant correlation was found between the LD-100 and pQCT measurement values in TBD and CoTh, suggesting that evaluation of the bone status, at least the bone status of the forearm, can be similarly evaluated at positions used by both systems.…”

Assessment of material, structural, and functional properties of the human skeleton by pQCT systems

“…Gorai et al [27], for instance, measured these parameters in more than 5000 patients and showed that values remain stable in 20-to 49-year-olds and thereafter decrease with increasing age. Sensitivity as determined by ROC analyses adjusted for age suggests that the variables determined for the radius may help differentiate women with vertebral fractures from healthy women.…”

A Trimodality Comparison of Volumetric Bone Imaging Technologies. Part III: SD, SEE, LSC Association With Fragility Fractures

“…However, only few have investigated the same using either pQCT (3,(17)(18)(19) or MRI (1,(20)(21)(22)(23). Other studies determined the association between vBMD derived from pQCT images and spinal (HRs or ORs: 1.1-1.9) (18,24-26), hip (HRs or ORs: 1.1-2.6) (24,26,27), or wrist (ORs: 0.51-1.87) (3) fractures, but these studies did not examine apparent bone microstructure.…”