Dual Energy Research Articles

6577 National Trends in Fragility Hip Fractures Among Community Dwelling Women With Low Femoral Neck Bone Mineral Density

Abstract Disclosure: A. Atri: None. C. Anastasopoulou: None. Introduction: Fragility hip fractures are a major public health burden and are considered a good measure of the quality of healthcare. However, contemporary trends in fragility hip fractures in women with low femoral neck bone mineral density (BMD) in the United States are not known. Methods: We used data from the National Health and Nutrition Examination Survey (NHANES) for the years 2009-10, 2013–14 and 2017–18 to include U.S. women aged ≥ 60 years with bone mineral density (BMD) T score ≤ -1 at the femur neck, which was measured by dual energy x-ray absorptiometry (DEXA) on Hologic Discovery Model A Densitometers (Hologic, Inc., Bedford, Massachusetts). Fragility fracture at the hip was defined as self-reported hip fracture resulting from a fall from standing height or less. Participants with missing BMD and fracture data were excluded. ANOVA was used for comparing means. The Cochran-Armitage test was utilized for trend analysis. Results: Overall, in women aged ≥ 60 years with femoral neck T score ≤ -1, the average age of women of low BMD decreased from 71(±7.2) years to 69.6 (±6.7) years, whereas the mean T-score modestly worsened from – 1.96 (±0.62) to -2.04 (±0.77) from 2009-10 to 2017-18. Similarly, the prevalence of women with T score ≤ -2.5 increased from 18.1% to 21.3%. We also found no significant change in proportion of women who reported treatment for osteoporosis (2009-10: 19.8%, 2013-14: 18.5%, 2017-18: 19.7%; p trend = 0.052). However, proportion of women who experienced fragility hip fractures decreased significantly (2009-10: 2.4%, 2013-14: 1.5%, 2017-18: 1.2%; p trend = 0.001). The mean age of index fragility hip fracture was 70.6 years in 2009-10, 68.3 years in 2013-14 and 71.7 years in 2017-18 (p = 0.001). Age stratified analysis showed a decreasing trend in proportion of women ≥ 80 years who experienced their index fragility hip fracture (2009-10: 25.9%, 2013-14: 14.7%, 2017-18: 15%; p trend = 0.001) and 70-79 years (2009-10: 40.9%, 2013-14: 21.1%, 2017-18: 35.8%; p trend = 0.001), while an increasing trend was seen in women 60–69 years (2009-10: 33.2%, 2013-14: 64.2%, 2017-18: 49.2%; p trend = 0.001). Discussion In this nationally representative cohort of community-dwelling US women with a low femoral neck BMD, we found a 50% decrease in burden of fragility hip fractures over a 10-year period from 2009-10 to 2017-18. This trend was observed despite worsening mean femoral neck T-scores, T score ≤ -2.5, and similar rates of osteoporosis treatment. Interestingly, the proportion of women who experienced their index fragility hip fracture showed a declining trend among the 70-79 years and ≥ 80 years age-groups. This change may be due to increasing awareness and utilization of measures to decrease falls such as exercise, nutrition, health education and environment modifications targeted towards the elderly population. Presentation: 6/2/2024

9288 National Trends in Fragility Hip Fractures Among Community Dwelling Women With Low Femoral Neck Bone Mineral Density

Abstract Disclosure: A. Atri: None. C. Anastasopoulou: None. Introduction: Fragility hip fractures are a major public health burden and are considered a good measure of the quality of healthcare. However, contemporary trends in fragility hip fractures in women with low femoral neck bone mineral density (BMD) in the United States are not known. Methods: We used data from the National Health and Nutrition Examination Survey (NHANES) for the years 2009-10, 2013–14 and 2017–18 to include U.S. women aged ≥ 60 years with bone mineral density (BMD) T score ≤ -1 at the femur neck, which was measured by dual energy x-ray absorptiometry (DEXA) on Hologic Discovery Model A Densitometers (Hologic, Inc., Bedford, Massachusetts). Fragility fracture at the hip was defined as self-reported hip fracture resulting from a fall from standing height or less. Participants with missing BMD and fracture data were excluded. ANOVA was used for comparing means. The Cochran-Armitage test was utilized for trend analysis. Results: Overall, in women aged ≥ 60 years with femoral neck T score ≤ -1, the average age of women of low BMD decreased from 71(±7.2) years to 69.6 (±6.7) years, whereas the mean T-score modestly worsened from – 1.96 (±0.62) to -2.04 (±0.77) from 2009-10 to 2017-18. Similarly, the prevalence of women with T score ≤ -2.5 increased from 18.1% to 21.3%. We also found no significant change in proportion of women who reported treatment for osteoporosis (2009-10: 19.8%, 2013-14: 18.5%, 2017-18: 19.7%; p trend = 0.052). However, proportion of women who experienced fragility hip fractures decreased significantly (2009-10: 2.4%, 2013-14: 1.5%, 2017-18: 1.2%; p trend = 0.001). The mean age of index fragility hip fracture was 70.6 years in 2009-10, 68.3 years in 2013-14 and 71.7 years in 2017-18 (p = 0.001). Age stratified analysis showed a decreasing trend in proportion of women ≥ 80 years who experienced their index fragility hip fracture (2009-10: 25.9%, 2013-14: 14.7%, 2017-18: 15%; p trend = 0.001) and 70-79 years (2009-10: 40.9%, 2013-14: 21.1%, 2017-18: 35.8%; p trend = 0.001), while an increasing trend was seen in women 60–69 years (2009-10: 33.2%, 2013-14: 64.2%, 2017-18: 49.2%; p trend = 0.001). Discussion In this nationally representative cohort of community-dwelling US women with a low femoral neck BMD, we found a 50% decrease in burden of fragility hip fractures over a 10-year period from 2009-10 to 2017-18. This trend was observed despite worsening mean femoral neck T-scores, T score ≤ -2.5, and similar rates of osteoporosis treatment. Interestingly, the proportion of women who experienced their index fragility hip fracture showed a declining trend among the 70-79 years and ≥ 80 years age-groups. This change may be due to increasing awareness and utilization of measures to decrease falls such as exercise, nutrition, health education and environment modifications targeted towards the elderly population. Presentation: 6/2/2024

6578 National Trends in Vitamin D Deficiency and Racial-Ethnic Differences Among US Women With Low Bone Mineral Density

Abstract Disclosure: A. Atri: None. C. Anastasopoulou: None. Introduction: Vitamin D (Vit D) plays a critical role in maintaining bone mineralization and its deficiency adversely impacts bone health. Contemporary trends of Vit D deficiency (VDD) and racial-ethnic differences in these trends among US women with low bone mineral density (BMD) are not well elucidated. Methods: We used data from the National Health and Nutrition Examination Survey (NHANES) for the years 2009-10, 2013–14 and 2017–18 to include U.S. women ≥ 50 years with femoral neck T score ≤ -1. Osteoporosis was defined by a T-score ≤ -2.5. BMD assessment in NHANES was not completed in 2011–12 and 2015–16, and therefore not included in the analysis. Femoral neck BMD was measured by dual energy x-ray absorptiometry (DEXA) on Hologic Discovery Model A Densitometers (Hologic, Inc., Bedford, Massachusetts). VDD was defined as serum 25(OH)D <30 nmol/L. Participants with missing data on race-ethnicity, BMD and Vit D data were excluded. Independent samples median test was used for comparing medians. The Cochran-Armitage test was utilized for trend analysis. Results: Overall, in women with low BMD, from 2009-10 to 2017-18, prevalence of osteoporosis increased from 13.7% to 16.9% while VDD decreased significantly from 5.6% to 2.3% (p trend = 0.001). When stratified by race-ethnicity, the prevalence of osteoporosis increased in Whites (14.1% to 17.6%, p trend = 0.001), Hispanics (12.6% to 13.7%, p trend = 0.001) and Other race-ethnicity (Asian/Mixed) (14.1% to 21.4%, p trend = 0.001), but a modest decrease was noted among the Black population (7.3% to 6.8%, p trend = 0.001). VDD was disproportionately high among Blacks (In 2009-10: 28.1% vs 4.2% in Whites, 5.4% in Hispanics and 10.7% among Others). However, significantly improving trends in VDD were observed among all the groups, regardless of race/ethnicity, to 12.5% prevalence among Blacks, 1.3% in Whites, 4.9% in Hispanics and 1.1% in the Other race ethnicity group (p trend = 0.001). Discussion In this contemporary analysis, rates of VDD have decreased from nearly 1 in 20 to 1 in 50 women with low BMD in the US. Highest prevalence of VDD was noted among Blacks, seen in nearly 1 in 3 Black women in 2009-10, with improvement to 1 in 8, in 2017-18. Similar favorable trends of decline in VDD were observed across all other racial-ethnic groups as well. Despite the overall improvement in VDD, prevalence of osteoporosis declined only among Black women, suggesting the potential role of other protective factors against osteoporosis among them. Nevertheless, VDD continues to remain prevalent in this high-risk group, emphasizing the need for public health interventions to bridge this gap. Presentation: 6/2/2024

12480 REMS Technology For The Bone Health Assessment After Hormonal Therapy In Transgender Subjects

Abstract Disclosure: F.A. Lombardi*: None. A. Russo: None. P. Pisani*: None. C. Stomaci*: None. F. Conversano*: None. R. Franchini*: None. M. Di Paola*: None. V. Racanelli*: None. S. Casciaro: None. Introduction: Sex steroid hormones play crucial roles in bone metabolism and the musculoskeletal system. These hormones interact with specific nuclear receptors, such as estrogen and androgen receptors, which are expressed in bone tissue. This interaction regulates the ongoing process of bone remodeling and induces positive effects on bone health.In this regard, it is crucial to examine the long-term impact of gender affirming hormone therapy (GAHT) on bone metabolism. Radiofrequency Echographic Multi-spectrometry (REMS) is a radiation-free technology for assessing bone mineral density (BMD) and fracture risk prediction by the analysis of the reference axial sites: lumbar spine (LS) and femoral neck (FN). REMS has been widely validated in comparison with Dual Energy X-ray Absorptiometry (DXA), showing good accuracy and precision (>90%), thereby representing a valid technology to monitor bone health status (BHS) in a short-term period. In this context, the goal of this preliminary clinical study was to track the bone health of transgender subjects for one year after starting treatment, using REMS, in order to comprehend the effects of GAHT on BHS. Methods: 7 transgender patients were recruited at Endocrinology Unit of Internal Medicine Department of Santa Chiara Hospital Trento (Italy). Among them were 4 individuals assigned male at birth (AMAB) undergoing therapy with oestradiol valerate 2 g/day and cyproterone acetate 25 mg/day, as well as 3 individuals assigned female at birth (AFAB) undergoing therapy with testosterone 25 mg/day. Before starting GAHT, patients underwent LS-DXA scan, followed by monitoring of BHS by REMS technology after 12 months from the start of treatment. Results: The results show an increase of T-score values in AMAB (-0,3 ± 0,3 REMS vs -1,8 ± 1,8 DXA) after estrogen treatment starting, and no effect on bone in AFAB subjects after GAHT (0.5 ± 0.4 REMS vs 0.9 ± 0.4 DXA); this is due to:-the protective effect of estrogen therapy in AMAB subjects against bone loss;-the combined effect of the decrease of estrogen together with the increase of testosterone in AFAB ones. Conclusions In summary, these initial findings indicate that REMS could be appropriate for monitoring the bone health status of these individuals, confirming the anticipated beneficial effects of estrogen therapy on bone loss in AMAB individuals. The limitation of the study is the lack of REMS data at the beginning of the treatment, but the possibility of carrying out the technique in subsequent evaluation times will allow us to evaluate the change in bone mass during hormonal reaffirmation therapy and compare it with the progress of the measurements obtained with DXA data ones. Presentation: 6/2/2024

Thermal conversion engineering of vanadium nitride-oxide cathode for high-rate aqueous Zn-ion battery

Vanadium-based materials are promising cathodes for high electrochemical performance aqueous Zn-ion batteries (AZIBs) due to their high specific capacity and multielectron redox reactions. However, vanadium-based materials suffer from low intrinsic conductivities and slow reaction kinetics, leading to poor rate performance. Here, we introduce vanadium nitride-oxide (VOVN) composites fabricated through a thermal conversion strategy, which exhibit high capacity and superior rate performance. The interface regulation of V2O3 and VN composite promotes charge carrier transport and enhances cathode reaction kinetics. Additionally, the dual energy storage mechanism in VOVN composites facilitates highly reversible Zn2+ storage processes. Consequently, the VOVN cathode demonstrates high discharge capacity (445.3 mAh g−1 at 0.1 A g−1), excellent rate performance (151.4 mAh g−1 at 30 A g−1), and fast diffusion coefficient (10−9–10−10 cm2 s−1). This study provides a straightforward and effective approach to developing high-performance cathodes for AZIBs.

Fundamentals of Dual Energy CT and its emerging applications in Bladder Cancer

Fundamentals of Dual Energy CT and its emerging applications in Bladder Cancer

Dual energy computed tomography in assessment of bone marrow edema in pathologies of the appendicular skeleton

BackgroundBone marrow edema cannot be detected on the conventional computed tomography scan. MRI has excellent diagnostic performance in detecting bone marrow edema but multiple difficulties in the emergency setting makes performing MRI logistically challenging. The aim of the study was to assess dual energy computed tomography accuracy for bone marrow edema in pathologies of the appendicular skeleton. This was based on color-coded maps and quantitative analysis of Hounsfield unit (HU) in subtraction images, compared with MRI. Materials and methodsProspective observational study was performed by including 60 patients who underwent Dual energy CT (DECT) and MRI. Statistical analysis was performed by calculating p-value and ROC curve analysis. The derived cut off value was used to identify bone marrow edema and diagnostic accuracy, sensitivity, specificity, negative predictive value and positive predictive value of DECT was calculated using MRI as gold standard. A further sub-analysis between the traumatic and non-traumatic groups was done. ResultsBone marrow edema on Color coded virtual non-calcium (VNCa) images and Mean HU of bone marrow edematous site was calculated. Attenuation difference between edematous bone marrow and rest of the bone were correlated with MRI, (p-value 0.0001). The sensitivity, specificity, negative predictive, positive predictive value, and diagnostic accuracy were 91.1, 93.3, 97.6, 77.8 and 91.67 % respectively. ConclusionOur results confirmed that Dual energy CT has high overall sensitivity, specificity and diagnostic accuracy in depicting bone marrow edema when compared to MRI, in various etiologies of the appendicular skeleton. This will lead to reduced missed cases by early detection of bone marrow edema secondary to fractures that are not identifiable in conventional CT. Marrow edema in DECT can be used as an indicator for disease activity and progression in conditions such as transient osteoporosis, tumour, arthritis, avascular necrosis and various other etiologies, generally missed in conventional radiography.

Preoperative Osteoporosis Is Associated With Increased Health Care Utilization and Compromised Pain and Function Improvement After Primary Total Hip Arthroplasty: A Prospective Cohort Analysis

BackgroundOsteoporosis (OP) has been linked to complications after total hip arthroplasty (THA), but its impact on health care utilization and patient-reported outcomes remains unclear. This study aimed to evaluate the association between: 1) pre-THA OP and health care utilization as well as patient-reported pain and function outcome measures; and 2) dual energy X-ray absorptiometry (DEXA) scan-based T-scores and the aforementioned outcomes. MethodsA retrospective analysis of prospectively collected data of primary THA (2015 to 2018) was performed (n = 5,321) from a validated academic institutional database of a large North American tertiary health care system; of which 4,074 (76.6%) completed 1-year follow-up. Outcomes included prolonged length of stay [LOS] > three days, discharge disposition, 90-day readmission, and 1-year reoperation, as well as Hip Disability and Osteoarthritis Outcome Score (HOOS]) Pain, HOOS-function (PS), and minimal clinically important difference thresholds (MCID), and satisfaction. ResultsThe prevalence of OP pre-THA was 56.9%, of which 39.8% were not prescribed OP medications and 15.3% had a DEXA scan. Compared to those who did not have OP, those who had OP were independently associated with higher odds of prolonged LOS, nonhome discharge, 90-day readmission, and 1-year reoperation (P < 0.005). Furthermore, they had significantly higher odds of failing to achieve MCID (odds ratio: 1.41 (95% confidence interval: 1.06 to 1.89)) for HOOS-PS and satisfaction (odds ratio: 1.5 (95% confidence interval: 1.16 to 1.93)) at one year. Higher T-scores were associated with lower odds of prolonged LOS, nonhome discharge, failure to achieve MCID in HOOS-Pain, and HOOS-PS. ConclusionsOver half of patients had OP; however, only 15.3% of patients had a DEXA scan before THA. Patients who had OP were at higher risk of prolonged LOS, nonhome discharge, 90-day readmission, and 1-year reoperation in addition to poor pain/function improvement and dissatisfaction one year after THA.

Excess dietary salt is associated with an altered bone strain index, degraded bone microarchitecture, vertebral fractures, and increased prevalence of osteoporosis in postmenopausal women-A study from a teaching hospital in southern India.

Excess dietary salt causes increased urinary calcium and this may lead to bone loss. We proposed to study the association between dietary salt intake and bone health in postmenopausal women from southern India. An observational study in which community-dwelling postmenopausal women were recruited. Daily salt intake and urine calcium/creatinine ratio were assessed. Bone biochemistry and densitometric parameters such as bone mineral density (BMD), trabecular bone score (TBS) vertebral fractures, and bone strain index (BSI) were assessed using Dual Energy X-Ray Absorptiometry (DXA). A total of 383 postmenopausal women with a mean ± SD age of 59.8 ± 7.2 years and BMI of 25.2 ± 4.6 kg/m2 were recruited. Among the participants, 165/383(43.1%) had osteoporosis at any site and 21% had moderate-severe vertebral fractures. The BMD at lumbar spine and femoral neck, TBS and BSI were significantly (p < 0.001) lower and the CTx was significantly (p = 0.008) higher among women with high salt intake (7.2 g/day) as compared to those with salt intake of <7.2 g/day. The prevalence of osteoporosis, low TBS, high BSI, and moderate-severe vertebral fractures significantly increased across low to high salt-intake categories. An ROC analysis showed that excess dietary salt was significantly associated with osteoporosis at any site with an AUC of 0.870 (95% CI: 0.832-0.907). On a multivariate analysis, excess salt intake conferred the highest odds of osteoporosis (OR: 2.296; 95% CI: 1.909-2.761). Excess dietary salt is associated with high urinary calcium and compromised bone health among postmenopausal women from southern India. This may be a modifiable risk factor in osteoporosis and warrants further research.

TCT-737 Dual Energy Computed Tomography Perfusion Score as a Predictor for Pulmonary Embolism Severity

TCT-737 Dual Energy Computed Tomography Perfusion Score as a Predictor for Pulmonary Embolism Severity

Comparison between bioelecrtical impedance analysis and dual energy X-ray absorptiometry for muscle mass assessment in patients with chronic intestinal failure

Comparison between bioelecrtical impedance analysis and dual energy X-ray absorptiometry for muscle mass assessment in patients with chronic intestinal failure

109 - Evaluation of dose calculation in Direct Density algorithm reconstruction images using dual energy CT for Radiotherapy

109 - Evaluation of dose calculation in Direct Density algorithm reconstruction images using dual energy CT for Radiotherapy

Assessment of Bone Mineral Density in Chronic Obstructive Pulmonary Disease Patients

Background: Main co-morbidities of chronic obstructive pulmonary disease that restricts physical exercise is osteoporosis. In this study we assess chronic obstructive pulmonary disease patients for osteoporosis, osteopenia and determine correlation of body mass index, number of pack years, severity of chronic obstructive pulmonary disease with bone mineral density Method and patients: This cross-sectional study was carried out on 61 chronic obstructive pulmonary disease patients.. Dual energy x-ray absorptiometry was used to evaluate the bone mineral densities at lumbar spine. According to WHO guidelines, patients with a T score greater than -1 were classified as having normal bone density, those with a T score of (-1 )to (-2) as having osteopenia, and those with a T score of less than -2.5 as having osteoporotic bone density. Results: Sixty - one chronic obstructive pulmonary disease patients were included in this study, 11 patients (18%) had normal bone mineral density, fifty patients had abnormal bone mineral density .Also thirty - two patients had osteoporosis(52.5%) and 18 (29.5%) had osteopenia. .BMD correlated directly with BMI (P value=0.009) and inversely with number of pack years (P = 0.000), ,BMD correlated inversely with severity of COPD (P = 0.001) . Conclusion: Patients with chronic obstructive lung disease had a higher chance of osteoporotic fractures and decreased bone mineral density.A lower BMI, more pack years, and a rise in the severity of the condition raised chance of osteoporosis..

Accelerated bone loss in late reproductive-aged and perimenopausal women with vitamin D insufficiency.

The association between serum vitamin D levels and bone mineral density (BMD) varies by race and gender. This study aimed to evaluate this relationship between serum vitamin D levels and BMD, and changes of BMD over time in Korean women. We analyzed data from 586 generally healthy Korean women aged 29-79 who underwent health check-ups at Seoul National University Gangnam Center between 2010 and 2011 (baseline measurement) and 2015-2016 (follow-up). Dual energy X-ray absorptiometry (DEXA) and serum 25-hydroxyvitamin D (25OH-D) level measurements were conducted. We assessed the association between serum 25OH-D levels and BMD, as well as changes in BMD over time. The mean age of participants was 51.3 ± 7.9years, with a mean follow-up interval of 4.6 ± 0.7years, and mean serum 25OH-D level of 20.6 ± 8.5ng/ml. Baseline serum 25OH-D levels did not correlate with BMD values at the lumbar spine, femoral neck, or total femur, nor with changes in BMD over time. A significant negative association was found between perimenopausal status and BMD changes at all sites, and between premenopausal status and lumbar bone mass, compared to postmenopausal status in the 25OH-D < 20ng/ml group. This association was not observed in women with higher serum 25OH-D levels. Serum 25OH-D levels did not correlate with BMD levels or changes in BMD overall. However, in late reproductive-aged and perimenopausal women with serum 25OH-D insufficiency, there was a significant association with accelerated bone loss.

The coexistence of low muscle mass and obesity evaluated by dual energy X-ray absorptiometry, rather than low muscle mass or obesity alone, is associated with macrovascular but not microvascular complications in patients with type 2 diabetes mellitus.

The prevalence of the coexistence of low muscle mass and obesity is increasing, particularly with a rising trend observed in patients diagnosed with type 2 diabetes mellitus (T2DM). However, the association between the coexistence of low muscle mass and obesity and diabetic complications remains unclear. This study aimed to investigate these associations in patients with T2D. A retrospective study was conducted, including 2387 hospitalized patients with T2DM. Data on demographic characteristics, biochemical parameters, diabetic complications and body composition was from electronic health records. The participants were categorized as control, low muscle mass, obesity and the coexistence of the low muscle mass and obesity groups according to the body compositions evaluated by dual-energy X-ray absorptiometry. Multiple logistic regression models were applied to assess the associations between the pattern of body composition and complications of diabetes. After adjustment for potential confounders, compared with patients in the control group, the odds ratios [95% confidence intervals (CIs)] of macrovascular complications of diabetes were 0.62 (95% CI, 0.27-1.39) for those in the low muscle mass group, 1.12 (95% CI, 0.59-2.11) in the obesity group, and 2.43 (95% CI, 1.16-5.07) in the coexistence of the low muscle mass and obesity group, respectively; the odds ratios (95% CIs) of microvascular complications of diabetes were 0.86 (95% CI, 0.52-1.43) for those in the low muscle mass group, 0.82 (95% CI, 0.53-1.26) in the obesity group, and 1.21 (95% CI, 0.69-2.15) in the coexistence of the low muscle mass and obesity group, respectively. According to our findings, the coexistence of low muscle mass and obesity, rather than low muscle mass or obesity alone, was significantly associated with a higher prevalence of macrovascular complications in hospitalized patients with T2DM. This association was not observed for diabetic microvascular complications.

Existing and Emerging Measures of Muscle Strength and Mass in the Assessment of Sarcopenia

Abstract Background Sarcopenia, an accelerated loss of muscle strength and mass is a major driver of adverse health outcomes in older people. The European Working Group on Sarcopenia recommends muscle strength assessment with handgrip strength (HGS) or five chair stands test (5CST) and muscle mass assessment with dual energy X-ray absorptiometry or bioelectrical impedance analysis (BIA). However, these methods can be contraindicated, unavailable or patients can be unable to perform them. We sought to compare the existing measures HGS, 5CST and BIA to emerging measures: quadriceps muscle strength (QMS) and muscle ultrasound. Methods Thirty-one participants from a local healthy ageing group (mean age 71±5 years, 80% female) were recruited to the FRAILMatics Physiological Cohort. Max HGS was assessed using the Jamar Plus+ dynamometer and 5CST timed from a standard height chair. Max QMS was measured with the Actiforce hand-held dynamometer. BIA was performed with the TANITA DC-430 MAP and the Sergi equation used to estimate appendicular skeletal muscle mass (ASMM). Rectus femoris muscle thickness (RFMT), vastus lateralis muscle thickness (VLMT) and anterior thigh muscle thickness (ATMT) measurements were taken using the linear array transducer on the GE Vscan Air point of care ultrasound system. Pearson correlation was used to examine the relationship between measures. Results Strong correlation was seen between max QMS and max HGS (r = 0.73, P &amp;lt;0.001); moderate correlation between RFMT, VLMT, ATMT and ASMM (r = 0.51, P &amp;lt;0.01; r = 0.56, P&amp;lt;0.01; r = 0.40, P &amp;lt;0.05). 5CST was not correlated with any of the measures (P &amp;gt;0.05). Conclusion In the assessment of sarcopenia, QMS and muscle ultrasound could be alternatives to HGS and BIA respectively, especially in cases where the latter are not available or contraindicated. 5CST appears less useful in the assessment of sarcopenia and may be more appropriate as a test of physical performance.

Effect of Fibroblast Growth Factor (FGF) 19 and 21 on Hip Geometry and Strength in Post-menopausal Osteoporosis (PMO)

Fibroblast Growth Factor (FGF) receptor signalling is important for skeletal development. The FGF19 subfamily which includes FGF19 and FGF21 are involved in bone metabolism, although their effects on bone mineral density (BMD) and bone strength remain unclear. To further characterise the influence of these two factors on the skeleton, we studied the association between circulating concentrations of FGF19 and 21 with BMD and parameters of hip geometry and strength in post-menopausal osteoporosis (PMO). The study cohort consisted of 374 women aged (mean [SD]) 68.7[12.3] years with PMO. FGF19 and FGF21 were measured in serum by ELISA. BMD was measured at the lumbar spine (LS), total hip (TH) and femoral neck (FN) (n = 277) by dual energy X-ray absorptiometry (DXA) and hip structural analysis (HSA) parameters (n = 263) at the narrow neck of the femur (NN), Intertrochanter (IT) and Femoral shaft (FS) were derived from DXA scans. FGF19 and 21 were not associated with prevalent fractures or BMD when corrected for covariates; age, BMI, smoking habits and alcohol intake. Log-transformed FGF 21 was negatively associated with HSA parameters including Outer Diameter (OD) (p = 0.019), Cross-sectional area (CSA) (p = 0.01), cross-sectional moment of inertia (CSMI) (p = 0.011), Section modulus (Z) (p = 0.002) and cortical thickness (Co Th) (p = 0.026) at the IT only. CSA, CSMI, Z and Co Th were significantly lower (p < 0.05) in women with FGF21 concentrations greater than the median (> 103.5 pg/ml). Our data suggest that FGF 21 may have potentially adverse effects on the skeleton. Further characterisation is needed, particularly as FGF 21 analogues or agonists may be used to treat obesity-related metabolic disorders.

Clinical Efficacy of Zoledronic Acid on Fracture Reduction in Youth with Primary and Secondary Skeletal Fragility.

Prior studies have demonstrated the safety and efficacy of zoledronic acid (ZA) to increase bone mineral density (BMD) in children. By contrast, the efficacy of ZA on fractures in the pediatric population remains uncertain. To investigate the effect of ZA on fracture rate in a clinical cohort of children and young adults with skeletal fragility. Retrospective cohort study. Academic medical center. 102 individuals (65 males; 39 with primary and 63 with secondary skeletal fragility) ages 0-21 years old treated with ZA for skeletal fragility between 2010 and 2017. ZA was prescribed at discretion of the treating clinician using a standardized protocol. The primary outcome was change in annualized fracture rate. Secondary outcomes included long bone and spine fracture rates. Areal BMD was analyzed in a subset of individuals with dual energy X-ray absorptiometry (DXA) scans. The overall median fracture rate decreased from 0.6 (IQR: 0.3-1.1) to 0 (IQR: 0-0.4) fractures per year, p<0.001, over a median treatment duration of 1.8 (IQR:0.6-3.0) years. Significant reductions in fracture rate were observed in both primary [1.0 (IQR: 0.6-1.5) to 0.3 (IQR: 0-0.6)] and secondary [0.5 (IQR: 0.1-0.8) to 0 (IQR: 0-0.3)] forms of skeletal fragility, p<0.001 for both. Significant reductions in fracture rate persisted when limited to long bone or long bone plus spine fractures. ZA treatment as a component of clinical care was associated with significant declines in fracture rate in this cohort of children and young adults with skeletal fragility.

Contrast and quantum noise in single-exposure dual-energy thoracic imaging with photon-counting x-ray detectors

Objective.Photon-counting x-ray detectors (PCDs) can produce dual-energy (DE) x-ray images of lung cancer in a single x-ray exposure. It is important to understand the factors that affect contrast, noise and the contrast-to-noise ratio (CNR). This study quantifies the dependence of CNR on tube voltage, energy threshold and patient thickness in single exposure, DE, bone-suppressed thoracic imaging with PCDs, and elucidates how the fundamental processes inherent in x-ray detection by PCDs contribute to CNR degradation.Approach.We modeled the DE CNR for five theoretical PCDs, ranging from an ideal PCD that detects every primary photon in the correct energy bin while rejecting all scattered radiation to a non-ideal PCD that suffers from charge-sharing and electronic noise, and detects scatter. CNR was computed as a function of tube voltage and high energy threshold for average and larger-than-average patients. Model predictions were compared with experimental data extracted from images acquired using a cadmium telluride (CdTe) PCD with two energy bins and analog charge summing for charge-sharing suppression. The imaging phantom simulated attenuation, scatter and contrast in lung nodule imaging. We quantified CNR improvements achievable with anti-correlated noise reduction (ACNR) and measured the range of exposure rates over which pulse pile-up is negligible.Main Results.The realistic model predicted overall trends observed in the experimental data. CNR improvements with ACNR were approximately five-fold, and modeled CNR-enhancements were on average within 10% of experiment. CNR increased modestly (i.e.<20%) when increasing the tube voltage from 90 kV to 130 kV. Optimal energy thresholds ranged from 50 keV to 70 keV across all tube voltages and patient thicknesses with and without ACNR. Quantum efficiency, electronic noise, charge sharing and scatter degraded CNR by ~50%. Charge sharing and scatter had the largest effect on CNR, degrading it by ~30% and ~15% respectively. Dead-time losses were less than 5% for patient exposure rates within the range of clinical exposure rates.Significance.In this study, we (1) employed analytical and computational models to assess the impact of different factors on CNR in single-exposure DE imaging with PCDs, (2) evaluated the accuracy of these models in predicting experimental trends, (3) quantified improvements in CNR achievable through ACNR and (4) determined the range of patient exposure rates at which pulse pile-up can be considered negligible. To the best of our knowledge, this study represents the first systematic investigation of single-exposure DE imaging of lung nodules with PCDs.

Safety and tolerability of a low glycemic load dietary intervention in adults with cystic fibrosis: a pilot study.

To achieve and maintain adequate weight, people with cystic fibrosis (CF) May often consume energy-dense, nutrient-poor foods high in added sugars and refined carbohydrates; however, little is known about the glycemic and metabolic effects of dietary composition in this patient population. The objective of this pilot study was to investigate the safety and tolerability of a low glycemic load (LGL) diet in adults with CF and abnormal glucose tolerance (AGT). Ten adults with CF and AGT completed this prospective, open-label pilot study. Mean age was 27.0 ± 2.1 years, 64% were female, and all had pancreatic insufficiency. Each participant followed his/her typical diet for 2 weeks, then transitioned to a LGL diet via meal delivery service for 8 weeks. The primary outcome was change in weight from baseline to study completion, with safety established if no significant decline was noted. Other key safety outcomes included change in hypoglycemia measured by patient report and continuous glucose monitoring (CGM). Exploratory outcomes included changes in other CGM measures, body composition by dual energy X-ray absorptiometry (DXA), and patient reported outcomes. There were no significant changes in weight or in subjectively-reported or objectively-measured hypoglycemia. Favorable non-significant changes were noted in CGM measures of hyperglycemia and glycemic variability, DXA measures of fat mass, and gastrointestinal symptom surveys. A LGL dietary intervention was safe and well tolerated in adults with CF and AGT. These results lay the groundwork for future trials investigating the impact of low-glycemic dietary interventions on metabolic outcomes in the CF population.