The aim of this study was to evaluate the longitudinal changes of trabecular bone score (TBS) during and after bisphosphonate (BP) treatment in postmenopausal Korean women with osteoporosis.
We analyzed 191 patients who took BP and underwent bone mineral density (BMD) test for the period from January 2010 to December 2015. The mean follow up period during treatment and after treatment was 22.8 months and 18 months, respectively. The TBS and BMD values were evaluated by the percent changes relative to the baseline.
In 191 patients, who treated with BPs, L-spine BMD increased 3.65±0.5% and TBS increased 0.26±0.4% from baseline during first 1 year. At 2 to 4 years, the changes of BMD and TBS from baseline gradually increased up to 9.3±3.25% and 2.69±0.98% and both results showed statistically significant correlation. In 86 patients who stopped BPs, L-spine BMD decreased -0.54±1.07% and TBS increased 0.33±1.96% from baseline during 3 years follow up period.
Lumbar spine TBS increase over time with BPs treatment although the changes were less than that of BMD. Also, it preserve for years after stopping treatment, as the changes of lumbar spine BMD. The results of BMD and TBS showed significant correlation during treatment but not during drug withdrawal.
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The purpose of this study was to calculate the measurement uncertainty of the process of bone mineral density (BMD) analysis using dual energy X-ray absorptiometry with traceability.
Between March 2015 and October 2016, among healthy participants in their 20s and 30s, the study included those who had not taken calcium, vitamin D supplements and steroids and were without a history of osteoporosis, osteopenia and diseases related to osteoporosis. Relational expression of the model was established based on Guide to the Expression of Uncertainty in Measurements and Eurachem and the uncertainty from each factor was evaluated.
The combined standard uncertainty was 0.015, while the expanded uncertainty was 0.0298. The factor-specific standard uncertainties that occurred in the process of measuring BMD were 0.72% for the calibration curve, 0.9% for the internal quality control (IQC) using Aluminum Spine Phantom, 0.58% for European Spine Phantom (ESP), and 0.9% for the inspector precision (IP).
The combined standard uncertainty of the spine BMD corrected with ESP was 0.015 when measured at one time and targeting one participant. The uncertainties of the accuracy of the IQC and the IP were higher than that of the other factors. Therefore, there will be a need for establishment of protocols to lower these uncertainties.
Although dual energy X-ray absorptiometry (DXA) is known to standard equipment for bone mineral density (BMD) measurements. Different results of BMD measurement using a number of different types of devices are difficult to use clinical practice. The purpose of this study was to evaluate discrepancy and standardizations of DXA devices from three manufactures using a European Spine Phantom (ESP).
We calculated the accuracy and precision of 36 DXA devices from three manufacturers (10 Hologic, 16 Lunar, and 10 Osteosys) using a ESP (semi-anthropomorphic). The ESP was measured 5 times on each equipment without repositioning. Accuracy was assessed by comparing BMD (g/cm2) values measured on each device with the actual value of the phantom. Precision was assessed by the coefficient of variation (CVsd).
Lunar devices were, on average, 22%, 8.3%, and 5% overestimation for low (L1) BMD values, medium (L2), and high (L3) BMD values. Hologic devices were, on average, 6% overestimation for L1 BMD, and 5% and 6.2% underestimation for L2 and L3 BMD values. Osteosys devices was, on average, 12.7% (0.063 g/cm2), 6.3% (0.062 g/cm2), and 5% (0.075 g/cm2) underestimation for L1, L2, and L3, respectively. The mean CVsd for L1-L3 BMD were 0.01%, 0.78%, and 2.46% for Lunar, Hologic, and Osteosys devices respectively.
The BMD comparison in this study demonstrates that BMD result of three different devices are significant different between three devices. Differences of BMD between three devices are necessary to BMD standardization.
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