Journal of Clinical Densitometry最新文献

Objective: This study was aimed to create and validate a risk prediction model for the incidence of osteopenia in individuals with abdominal obesity.

Methods: Survey data from the National Health and Nutrition Examination Survey (NHANES) database for the years 2013–2014 and 2017–2018 was selected and included those with waist circumferences ≥102 m in men and ≥88 cm in women, which were defined as abdominal obesity. A multifactor logistic regression model was constructed using LASSO regression analysis to identify the best predictor variables, followed by the creation of a nomogram model. The model was then verified and evaluated using the consistency index (C-index), area under the receiver operating characteristic (ROC) curve (AUC), calibration curve, and decision curve analysis (DCA).

Results Screening based on LASSO regression analysis revealed that sex, age, race, body mass index (BMI), alkaline phosphatase (ALP) and Triglycerides (TG) were significant predictors of osteopenia development in individuals with abdominal obesity (P < 0.05). These six variables were included in the nomogram. In the training and validation sets, the C indices were 0.714 (95 % CI: 0.689–0.738) and 0.701 (95 % CI: 0.662–0.739), respectively, with corresponding AUCs of 0.714 and 0.701. The nomogram model exhibited good consistency with actual observations, as demonstrated by the calibration curve. The DCA nomogram showed that early intervention for at-risk populations has a net positive impact.

Conclusion: Sex, age, race, BMI, ALP and TG are predictive factors for osteopenia in individuals with abdominal obesity. The constructed nomogram model can be utilized to predict the clinical risk of osteopenia in the population with abdominal obesity.

Introduction: Poor eating habits and a sedentary lifestyle can impair health. Regular physical activity improves the quality of life and is essential for bone health. Therefore, the present study aimed to evaluate the effects of the cafeteria diet on bone quality of sedentary and exercised rats.

Methods: Sixty young male Wistar rats were divided into six groups (n=10) according to diet composition and activity level, being: SD+CON, standard diet and control; SD+SED, standard diet and sedentary; SD+EX, standard diet and exercised; CD+CON, cafeteria diet and control; CD+SED, cafeteria diet and sedentary; CD+EX, cafeteria diet and exercised. The exercise protocol consisted of 10 ladder-climbing sessions/day, 5 days/week, and the sedentary rats were maintained in individual cages with limited mobility. Body mass and food intake were evaluated weekly. After 10 weeks, the animals were euthanized, and white adipose tissue was collected. The bone structure was evaluated by densitometry, mechanical tests, histomorphometric, and micro-computed tomography analyses.

Results: The cafeteria diet increased adipose tissue (p<0.001), decreased bone mineral density (p=0.004), and impaired biomechanical properties (p<0.05) and histomorphometry parameters (p=0.044). The sedentarism decreased bone mineral density (p<0.001) and biomechanical properties (p<0.05), and the exercise did not improve bone properties.

Conclusion: In this experimental model, it was concluded that the cafeteria diet and a sedentary lifestyle negatively affect bone, and ladder-climbing exercise could not prevent the effects of the unhealthy diet.

Osteoporosis can currently be diagnosed by applying the WHO classification to bone mineral density (BMD) assessed by dual-energy x-ray absorptiometry (DXA). However, skeletal factors other than BMD contribute to bone strength and fracture risk. Lumbar spine TBS, a grey-level texture measure which is derived from DXA images has been extensively studied, enhances fracture prediction independent of BMD and can be used to adjust fracture probability from FRAX® to improve risk stratification. The purpose of this International Society for Clinical Densitometry task force was to review the existing evidence and develop recommendations to assist clinicians regarding when and how to perform, report and utilize TBS. Our review concluded that TBS is most likely to alter clinical management in patients aged ≥ 40 years who are close to the pharmacologic intervention threshold by FRAX. The TBS value from L1-L4 vertebral levels, without vertebral exclusions, should be used to calculate adjusted FRAX probabilities. L1-L4 vertebral levels can be used in the presence of degenerative changes and lumbar compression fractures. It is recommended not to report TBS if extreme structural or pathological artifacts are present. Monitoring and reporting TBS change is unlikely to be helpful with the current version of the TBS algorithm. The next version of TBS software will include an adjustment based upon directly measured tissue thickness. This is expected to improve performance and address some of the technical factors that affect the current algorithm which may require modifications to these Official Positions as experience is acquired with this new algorithm.

Introduction: Measurement of bone mineral density (BMD) with quantitative CT (QCT) carries several advantages over other densitometric techniques, including superior assessment of the spine. As most QCT studies evaluated the lumbar spine, measurements of the thoracic spine are limited. We performed QCT analysis of the thoracic spine in a cohort of patients with primary hyperparathyroidism. Materials and methods: This study was a retrospective QCT analysis of the thoracic spine on ¹⁸F-fluorocholine PET/CT scans in patients with primary hyperparathyroidism patients between March 2018 and December 2022. Correlations between QCT-derived BMD or Hounsfield units (HU) and demographic data, laboratory parameters, results from histopathological examination after parathyroidectomy and results of DXA imaging were analyzed, when available. Results: In 189 patients, mean QCT-derived BMD at the thoracic spine was 85.6 mg/cm³. Results from recent DXA were available in 122 patients. Mean thoracic QCT-derived BMD and HU were significantly correlated with DXA-derived BMD in lumbar spine, total hip and femoral neck and with the lowest T-score at DXA imaging. Only weak correlations were found with BMI or ¹⁸F-fluorocholine uptake, while no significant correlations were found with adenoma weight, PTH or calcium levels. Conclusion: Our study confirms correlation between QCT-derived BMD in the thoracic spine with age and DXA-derived BMD measurements within a population of patients with primary hyperparathyroidism. Establishment of reference BMD values for individual thoracic vertebrae, may allow direct osteoporosis classification on thoracic CT imaging.

Introduction: Osteoporosis indicates weakened bones and heightened fracture susceptibility due to diminished bone quality. Dual-energy x-ray absorptiometry is unable to assess bone strength. Volumetric bone mineral density (vBMD) from quantitative computed tomography (QCT) has been used to establish guidelines as equivalent measurements for osteoporosis. QCT-based finite element analysis (FEA) has been implemented using calibration phantoms to establish bone strength thresholds based on the established vBMD. The primary aim was to validate vertebral failure load thresholds using a phantom-less approach with previously established thresholds, advancing a phantom-free approach for fracture risk prediction.

Methodology: A controlled cohort of 108 subjects (68 females) was used to validate sex-specific vertebral fracture load thresholds for normal, osteopenic, and osteoporotic subjects, obtained using a QCT/FEA-based phantom-less calibration approach and two material equations.

Results: There were strong prediction correlations between the phantom-less and phantom-based methods (R2: 0.95 and 0.97 for males, and R2: 0.96 and 0.98 for females) based on the two equations. Bland Altman plots and paired t-tests showed no significant differences between methods. Predictions for bone strengths and thresholds using the phantom-less method matched those obtained using the phantom calibration and those previously established, with ≤4500 N (fragile) and ≥6000 N (normal) bone strength in females, and ≤6500 N (fragile) and ≥8500 N (normal) bone strength in males.

Conclusion: Phantom-less QCT-based FEA can allow for prospective and retrospective studies evaluating incidental vertebral fracture risk along the spine and their association with spine curvature and/or fracture etiology. The findings of this study further supported the application of phantom-less QCT-based FEA modeling to predict vertebral strength, aiding in identifying individuals prone to fractures. This reinforces the rationale for adopting this method as a comprehensive approach in predicting and managing fracture risk.

The Craig's test is a clinical assessment used to quantify femoral version. The validity of the Craig's test has been called into question due to instances where the test exhibits relatively poor correlation with three-dimensional imaging. Our study purpose was to use dual-energy X-ray absorptiometry (DXA) to indirectly assess the validity of the Craig's test. Twenty-three volunteers (n = 46; each hip analyzed separately) received two hip DXA scans using two different methods of positioning. During the first scan, a standard-sized wedge, the conventional tool of hip positioning for DXA scans, was used to fixate the legs without regard for individual levels of femoral version. For the second scan, the participants’ hips were manually positioned according to their degree of femoral version determined by the Craig's test. We hypothesized that the bone mineral density (BMD) values from the customized positions would be lower due to the X-ray beams hitting the femoral neck perpendicularly. A paired t-test revealed weak evidence of a difference between BMD readings of the conventional and customized positions (p-value = 0.065); moreover, contrary to our hypothesis, the BMD readings obtained in the standard position were lower than those obtained in the customized position, albeit not significantly. Our findings suggest that the Craig's test is not a valid clinical assessment of true femoral version. A secondary conclusion is that the widespread use of the standard wedge for hip positioning during DXA scans is a better option than trying to find a customized position that is based on findings of the Craig's test.

Bone disease is a common complication following liver transplantation, often overlooked in clinical practice. Clinical diagnosis of post-liver transplantation bone disease is challenging, and there have been few case report in the literature. This case report presents a patient who underwent two liver transplant surgeries, exhibited good daily activity, and did not display typical clinical symptoms such as fatigue, bone pain, or spinal deformities associated with prolonged sitting or standing. However, within the fifth year after the second liver transplant, the patient experienced two consecutive fractures. In March 2023, the patient underwent the first bone density test, which revealed osteoporosis. This case highlights the fact that severe fractures after liver transplantation may not necessarily be accompanied by typical symptoms of bone disease. Without timely examination and early prevention, serious consequences may arise. Therefore, this condition requires attention, proactive prevention, early detection, and timely treatment. Additionally, a retrospective analysis of the patient's previous laboratory data revealed persistent abnormalities in serum markers such as hypocalcemia and elevated alkaline phosphatase levels after liver transplantation, emphasizing the importance of monitoring these serum markers.

The precision for spine bone mineral density (BMD) worsens as vertebrae are excluded, so recommendations are needed for least significant change (LSC) for spine BMDs based on fewer than 4 vertebrae. The task force recommends re-analysis of each facility's L1-L4 in-house precision study to determine the precision in order to calculate the LSC for each combination of 2 or 3 reported vertebrae. The task force recommended not reporting spine BMDs based on single vertebral bodies for either the diagnosis or monitoring of osteoporosis. Specific data for studies assessing the precision of two non-contiguous vertebrae are mixed, but ultimately the task force recommended that spine BMD based on 2 non-contiguous vertebrae can be used for the diagnosis and monitoring of osteoporosis.

Incomplete atypical femur fractures (iAFFs) are associated with the long-term use of anti-resorptive therapies. Although X-rays are typically used to screen for iAFFs, images from dual-energy X-ray absorptiometry (DXA) offer an alternate method for detecting iAFFs. Although a previous 2019 ISCD Official Position on this subject exists, our task force aimed to update the literature review and to propose recommendations on reporting findings related to iAFFs that may be observed on DXA images. The task force recommended that full-length femur imaging (FFI) from DXA can be used as a screening tool for iAFFs. The presence of focal lateral cortical thickening and transverse lucencies should be reported, if identified on the FFI. This task force proposed a classification system to determine the likelihood of an iAFF, based on radiographic features seen on the FFI. Lastly, the task force recommended that the clinical assessment of prodromal symptoms (pain) is not required for the assessment of FFI.

After 15 months of preparation by task force chairs and teams, ISCD's 9th Position Development Conference (PDC) convened in Northbrook, IL, USA on March 28th and 29th, 2023 to approve new ISCD Official Positions in the topic areas of DXA Reporting, Follow-up BMD Testing and TBS Application and Reporting. Three teams of participants work to bring the PDC to fruition: the Steering Committee, Task Forces and Chairs, and the Expert Panel. To reach agreement on draft Official Positions, the PDC follows a scripted process with the UCLA/RAND Appropriateness Method (UCLA/RAM) as its foundation. Multiple rounds of data review, public debate and voting resulted in 32 new or modified Official Positions. Six companion position papers are also published along with this Executive Summary, serving as the detailed substantiation for the Official Positions. This Executive Summary reviews the personnel groups, activities and products of the 2023 PDC, with the entirety of the updated 2023 Official Positions presented in Appendix A. New Official Positions are highlighted in bold.