Prescreening For Osteoporosis With Forearm Bone Densitometry In Health Examination Population

Background: Early detection and timely prophylaxis can retard the progression of osteoporosis. The purpose of this study was to determine the usefulness of peripheral Dual Energy X-ray Absorptiometry(DXA) for osteoporosis screening. We utilized AKDX-09W-I, a domestic brand instrument to perform peripheral DXA. Briefly, we acquired bone mineral density (BMD) data from manufacturer-supplied density-gradient phantoms and 30 volunteers to investigate its accuracy and precision, then we measured BMD from 150 volunteers using both AKDX (left forearm) and Hologic Discovery Wi (left forearm, left hip and L1 - L4 vertebrae) simultaneously. Correlation analysis of BMD results from two instruments was assessed by simple linear regression, the Receiver Operating Characteristic (ROC) curves and Areas Under the Curves (AUCs) were evaluated for the diagnostic value of left forearm BMD from AKDX in detecting osteoporosis.Results: In vitro precision errors of AKDX BMD were 0.40%, 0.20%, 0.19%, respectively, on low-, medium-, and high-density phantom; in vivo precision was 1.65%. Positive correlation was observed between AKDX BMD and Hologic BMD at the forearm (r = 0.670), L1–L4 (r = 0.430, femoral neck (r = 0.449), and total hip (r = 0.559). With Hologic DXA T-score as the gold standard, the sensitivity of AKDX T-score < -1 for identifying suboptimal bone health was 63.0% and 76.1%, respectively, at the distal one-third radius and at any site, and the specificity was 73.9% and 90.0%, respectively; the AUCs were 0.708 and 0.879. The sensitivity of AKDX T-score ≤ -2.5 for identifying osteoporosis at the distal one-third radius and at any site was 76.9% and70.4%, respectively, and the specificity was 80.4% and 78.0%, respectively; the AUCs were 0.823 and 0.778.Conclusions: Peripheral DXA appears to be a reliable tool for prescreening for osteoporosis.

Correlation between MCI/Sapori screening tools and DXA results and between MCI/Sapori and Frax tool for estimating fracture risk

Background: Peripheral Dual-energy X-ray absorptiometry (DXA) can be applied to identify low bone mineral density (BMD) patients, however, DXA is not sufficiently available in many countries. Thus, the use of simpler and cheaper screening tools than DXA to detect low BMD become indispensable. Objectives: The objective of this study was to correlate São Paulo osteoporosis risk index (Sapori) and mandibular cortical index (MCI) screening tools with the femur DXA results of patients in our sample of Brazilian women. A secondary objective was to assess which of these screening tools better correlates with the results of the Frax tool. Material and Methods: Exams of women who had undergone panoramic radiographic examination at the beginning of dental treatment and peripheral DXA for screening osteoporosis from 2010 to 2014 were included. The MCI was evaluated, and Sapori and Frax were calculated with their available online software tools. Spearman correlation was performed to analyse the level of correlation between femur T-scores (and MCI and Sapori values, as well to perform the level of correlation between Frax and MCI and Sapori values. Results: The spearman correlation comparing the numerical T-score values and the categorical values of MCI (rs=-0.274), and of Sapori (rs=-0.470), showed a statistically significant inverse correlation for both equations (p<0.01). The Spearman equation comparing the values obtained with Frax and MCI did not show a statistically signifcant correlation (p>0.01). But the equation comparing the values obtained with Frax and Sapori showed a positive, moderate and statistically significant correlation between them (rs=0.460). Conclusion: MCI is not a reliable screening tool to identify women with low BMD or Osteoporosis, whereas more optimistic results were observed for the Sapori.

Is radius bone mineral density helpful for fracture risk assessment?

Although peripheral DXA is not recommended for the diagnosis of osteoporosis or to monitor osteoporotic treatments, its use for fracture risk assessment is supported by several studies. In addition, its potential interest is supported by the recent demonstration, in prospective cohorts, of the contribution of distal radius microstructure and strength, assessed by high-resolution peripheral QCT (HRpQCT), to predict incident fractures beyond the classical clinical tools (femoral neck BMD and FRAX). Indeed, areal BMD measured by DXA at the ultra-distal radius is highly correlated with bone strength derived from HRpQCT measurements at the same site. Ultra-distal radius areal BMD is therefore highly associated with fracture risk, with associations of higher magnitude than at the “classically recommended” one-third distal radius. Furthermore, ultra-distal radius areal BMD is also associated with incident fractures in non-osteoporotic women in women with T-score > –2.5 SD on hip and spine DXA or women with FRAX score below the intervention threshold for age. Since more than half of low-trauma fractures occur in individuals not identified as being at high risk by BMD testing at the spine or hip, radius bone mineral density may help to refine fracture risk in patients with osteopenia defined by central DXA (spine or hip), or relatively few clinical risk factors.