Dual-energy X-ray Absorptiometry Measurements Research Articles

Mineral bone disorder and osteoporosis in hemodialysis patients

BackgroundBone disease is common in patients undergoing hemodialysis. It is the result of bone turnover abnormalities and the decrease of bone mineral density (BMD). We aimed to determine the usefulness of serum bone turnover markers and BMD measurement by dual-energy x-ray absorptiometry (DXA) in hemodialysis patients.MethodsWe conducted a cross-sectional study including 90 hemodialysis for more than 12 months. Bone mineral density was assessed by DXA. Peripheral blood samples were obtained from each patient before dialysis in a fasting state within a week of the DXA. Biochemical variables of calcium and phosphate were measured. One bone formation marker (bone-specific alkaline phosphatase (bAP), one bone resorption marker (carboxy-terminal telopeptides of type 1 collagen (CTX)) were measured. Total alkaline phosphatase (TAP), intact parathyroid hormone (PTH) and fibroblast growth factor 23 (FGF23) which is a bone-derived hormone were also measured.ResultsCTX values were 6.25 times higher than the normal limit of the assay. Bone alkaline phosphatase levels were less than 10 ng/mL in 28.8% of cases. 23% of patients have osteoporosis and 45% have osteopenia. Femoral BMD had negative correlations with age and PTH levels. FGF23 levels were significantly increased in patients with osteoporosis affecting the lumbar. The levels of bAP and CTX showed a positive correlation. Both circulating bAP and CTX levels showed also positive correlations with PTH levels. Fractures, observed in 12.2% of cases, were associated with low PTH values and the existence of osteoporosis.ConclusionsOur study showed that osteoporosis and fracture are common in dialysis patients. The reduced BMD was associated with advanced age and elevated levels of PTH. Markers of bone turnover and FGF23 may play a role in the diagnosis of bone disease in hemodialysis patients. DXA measurement is necessary for the monitoring for bone loss.

Adherence to healthy diet is related to better linear growth with open growth plate in adolescent girls

Nutritional status can affect the linear growth of bones during puberty by affecting growth plate (GP) chondrocytes. We hypothesized that there is a relationship between dietary patterns and bone age on girls who have experienced height loss. This cross-sectional study was conducted on 350 girls aged 12-13 years with open GP, and major dietary patterns were determined using the factor analysis method. Dual-energy x-ray absorptiometry measurement of participant’s wrist was performed to determine GP openness and bone age. In the present study, 70.3% of participants had bone age below chronological age. Three major dietary patterns—healthy, high sugar and salt, and Western diet—were identified using findings of dietary intake. Adherence to the healthy diet led to significant increase in height, weight, body mass index, and other components of body composition such as lean body mass (P < .001). Among these dietary patterns, we found only a significant association between healthy diet and difference between bone and chronological age (B = –0.106). In the present study, adherence to a healthy diet was associated with increase in bone age (P = .02). Healthy dietary pattern with an emphasis on enough intake of plant protein and white meat was associated with better linear growth.

Clinical and Molecular Aspects of Senataxin Mutations in Amyotrophic Lateral Sclerosis 4.

ObjectiveTo determine the clinical and molecular features in patients with amyotrophic lateral sclerosis 4 (ALS4) due to mutations in the senataxin (SETX) gene and to develop tools for evaluating SETX variants.MethodsOur study involved 32 patients, including 31 with mutation in SETX at c.1166 T>C (p.Leu389Ser) and 1 with mutation at c.1153 G>A (p.Glu385Lys). Clinical characterization of the patients included neurological examination, blood tests, magnetic resonance imaging (MRI), and dual‐energy x‐ray absorptiometry (DEXA). Fibroblasts and motor neurons were obtained to model the disease and characterize the molecular alteration in senataxin function.ResultsWe report key clinical features of ALS4. Laboratory analysis showed alteration of serum creatine kinase and creatinine in the Leu389Ser ALS4 cohort. MRI showed increased muscle fat fraction in the lower extremities, which correlates with disease duration (thigh fat fraction R 2 = 0.35, p = 0.01; lower leg fat fraction R 2 = 0.49, p < 0.01). DEXA measurements showed lower extremities are more affected than upper extremities (average fat z scores of 2.1 and 0.6, respectively). A cellular assay for SETX function confirmed that like the Leu389Ser mutation, the Glu385Lys variant leads to a decrease in R loops, likely from a gain of function.InterpretationWe identified clinical laboratory and radiological features of ALS4, and hence they should be monitored for disease progression. The molecular characterization of R‐loop levels in patient‐derived cells provides insight into the disease pathology and assays to evaluate the pathogenicity of candidate mutations in the SETX gene. ANN NEUROL 2020;87:547–555

Fat and Fat-Free Mass of Preterm and Term Infants from Birth to Six Months: A Review of Current Evidence.

To optimize infant nutrition, the nature of weight gain must be analyzed. This study aims to review publications and develop growth charts for fat and fat-free mass for preterm and term infants. Body composition data measured by air displacement plethysmography (ADP) and dual energy X-ray absorptiometry (DXA) in preterm and term infants until six months corrected age were abstracted from publications (31 December 1990 to 30 April 2019). Age-specific percentiles were calculated. ADP measurements were used in 110 studies (2855 preterm and 22,410 term infants), and DXA was used in 28 studies (1147 preterm and 3542 term infants). At term age, preterm infants had higher percent-fat than term-born infants (16% vs. 11%, p < 0.001). At 52 weeks postmenstrual age (PMA), both reached similar percent-fat (24% vs. 25%). In contrast, at term age, preterm infants had less fat-free mass (2500 g vs. 2900 g) by 400 g. This difference decreased to 250 g by 52 weeks, and to 100 g at 60 weeks PMA (5000 g vs. 5100 g). DXA fat-free mass data were comparable with ADP. However, median percent-fat was up to 5% higher with DXA measurements compared with ADP with PMA > 50 weeks. There are methodological differences between ADP and DXA measures for infants with higher fat mass. The cause of higher fat mass in preterm infants at term age needs further investigation.

Dietary Calcium to Digestible Phosphorus Ratio for Optimal Growth Performance and Bone Mineralization in Growing and Finishing Pigs.

Simple SummaryMinimizing the use of dietary non-renewable mineral phosphates improves the sustainability of phosphorus use in growing-finishing pigs. As the phosphorus metabolism is closely linked to calcium, this experiment compared three dietary calcium to digestible phosphorus ratios within two phosphorus levels to determine the optimum levels for growth performance and bone mineralization. The lowest calcium level was insufficient for an efficient metabolic use of P, the medium level was sufficient to maximize growth performance and highest level further improved bone mineralization. The low digestible phosphorus level enabled a complete removal of supplemented mineral phosphates in the finisher period, which resulted, per pig, in a decrease of its use by 65% and a decrease of the calculated P excretion by 41%, without impaired growth performance. However, a reduced bone mineralization was observed. This study shows that there is potential to reduce the digestible phosphorus compared to practiced levels in grower–finisher pigs and shows that the optimal calcium to digestible phosphorus ratio needs to be maintained at the upper range of the actually available recommendations.Within the context of maximizing the use of dietary phosphorus, a growing-finishing pig study was conducted to determine the optimal total dietary calcium (Ca) to digestible phosphorus (dP) ratio and to verify the possibility of mineral phosphate removal during the finishing period on growth performance and mineral status. The potential for replacing chemical and mechanical bone properties by dual energy X-ray absorptiometry (DXA) measures on non-dissected feet was also verified. Three Ca to dP ratios (2.2:1, 2.5:1 and 2.8:1) within two dP levels (P+, P–) were fed during 91 days to 84 pigs. The grower and finisher P+ diets contained 3.0 and 2.4 and P– diets contained 2.5 and 1.7 g dP/kg, respectively. Growth performance and blood serum mineral content were independent of treatments, except that 2.2:1 impaired finisher feed conversion ratio compared to 2.5:1 and 2.8:1. Urinary P concentration increased by 37% in 2.2:1 compared to 2.5:1 and 2.8:1. Maximal load on bone and DXA mineral density were reduced in 2.2:1 compared to 2.8:1. Bone ash and volumetric density were reduced in 2.2:1 and 2.5:1 compared to 2.8:1. Diet P– reduced bone ash, maximal load, volumetric density and DXA bone mineral content and density. No interaction was observed between Ca and dP level. Therefore, 2.2:1 was insufficient for an efficient metabolic use of P, 2.5:1 was sufficient to maximize growth performance and 2.8:1 further improved bone mineralization. Increasing dietary Ca did not impair bone zinc content. Diets P– without supplemented mineral phosphates during the finisher period resulted, per pig, in a decrease of its use by 65% and of the calculated P excretion by 41%, without impaired growth performance. Finally, DXA data responded to dietary treatments as did labor intensive chemical and mechanical bone properties.

Seasonal Change in Body Composition and Physique of Team Sport Athletes.

Walker, EJ, Aughey, RJ, McLaughlin, P, and McAinch, AJ. Seasonal change in body composition and physique of team sport athletes. J Strength Cond Res 36(2): 565-572, 2022-Body composition of team sport athletes was measured at 3 points across the preseason and competitive season. This repeated-measures study was conducted in 46 professional Australian football (AF) (age 23.8 ± 3.8 years), 26 soccer (age 22.7 ± 4.7 years), and 33 rugby union players (age 28.1 ± 4.2 years). A mixed-design analysis of variance was used to determine change across the season, and Pearson's correlation was used to determine the relationship between different measures. Anthropometry, dual-energy x-ray absorptiometry (DXA), and 3-dimensional (3D) scan technology were used in AF and soccer, whereas only DXA was used in rugby. Body mass remained unchanged for both AF and soccer with gains in lean mass (p < 0.01), from preseason to early in the competitive season. Skinfold measures declined in AF (p < 0.001) and soccer (p < 0.05) across the season, whereas DXA-measured fat mass only declined in soccer (p < 0.01). Rugby backs (p < 0.01) and forwards (p < 0.001) reduced body fat and gained lean mass from preseason to in-season with forwards having greater relative and absolute changes as measured by DXA. 3D technology did not show change across the season. Dual-energy x-ray absorptiometry body fat percent and the sum of skinfold correlation were large (r = 0.74 [p < 0.001, CI 0.67-0.81]). The greatest change in body composition occurs from the beginning of preseason to the start of competition, with changes returning to baseline levels toward the end of season. Dual-energy x-ray absorptiometry and skinfold measures were moderately correlated, providing a good alternative to track change in subcutaneous fat in AF and soccer athletes.

P500 Adiposity among IBD patients

Abstract Background Inflammatory bowel disease (IBD) has been traditionally associated with malnutrition and increased prevalence of underweight status. Nevertheless, according to recent reports, there appears to be an increase in the percentage of overweight individuals among patients with Crohn’s disease (CD) or ulcerative colitis (UC). In the present study, we aimed to evaluate the body composition of a cohort of Greek patients with IBD. Methods We analysed data from 88 patients with IBD (CD:58, UC:30, female: 45). Body mass index (BMI) was calculated and waist circumference (WC) was measured in all participants. Body composition was evaluated with a multi-frequency bioelectrical impedance segmental body composition analyser (BIA) (Tanita MC-780) and with dual-energy X-ray absorptiometry (DXA). Results 9.1% (n = 8) of patients had low BMI (&amp;lt;18.5), 53.4% (n = 47) normal, 22.7% (n = 20) were overweight and 14.8% (n = 13) obese. No differences were seen between CD vs. UC. Furthermore, 27.3% (n = 24) of women had WC &amp;lt; 80 cm and 27.3% (n = 24) of men had &amp;lt; 94 cm. Referring to % total body fat, as reported by BIA, 46.5% (n = 20) of men and 11.1% (n = 5) of women had total body fat &amp;lt;20%, 46.5% (n = 20) of men and 44.4% (n = 20) of women had 21–30%, 7% (n = 3) of men and 28.9% (n = 13)of women 31–40% and 15.6% (n = 7)of women &amp;gt;41%. According to DXA measurements, 25.6% (n = 11) of men had total body fat &amp;lt;20%, 46.5% (n = 20) of men and 15.6% (n = 7) of women had 21–30%, 25.6% (n = 11) of men and 46.7% (n = 21) of women 31–40% and 2.3% (n = 1) of men and 37.8% (n = 17) of women &amp;gt;41%. There was no significant difference in % total body fat between CD and UC patients in either measurement. We observed a significant difference between the two methods regarding the estimation of % body fat, as BIA measurements were lower than those obtained with DXA (p &amp;lt; 0.001, median = 5.53%, 95% confidence interval = 4.82–6.24%). Nevertheless there was a significant correlation between BIA and DXA measurements in the same individual (r2 = 0.9025, p &amp;lt; 0.001). Conclusion We found a large proportion of overweight/obese patients in our IBD cohort. The association with increased WC may imply that the total abdominal fat is increased in such patients. As excessive fat content has been shown to negatively affect IBD patients in multiple ways, our results emphasise the need for better assessment of body composition and dietetic interventions in this population.

Trends in bone mineral density among nutritional status categories of Vojvodina elderly population

Introduction/Objective. Low bone mineral density (BMD) is commonly associated with alterations of nutritional status. The aims of the present study were to evaluate the prevalence of low BMD and its associated nutritional risk factors in Vojvodina population and to use linear regression equations to predict the BMD by using a simple marker of nutritional status, body mass index (BMI). Methods. In this retrospective, cross-sectional study, the study population included subjects who were undergoing assessment of BMD between January and December 2017, and who have met the study inclusion criteria. A total of 1974 patients (1866 women and 108 men) were included in this analysis of nutritional status according to anthropometry and BMI index, and dual-energy X-ray absorptiometry (DEXA) measurements of BMD of the femoral neck and lumbar spine. The relationship between BMI and BMD was analyzed by linear regression equation. Results. Median age was 63 (56?70) years. Considering nutritional status category, there were 40% overweight, 31% obese and 29% normal weight subjects. In most of the sample, the subjects had low BMD, 37% had osteopenia, and 25% had osteoporosis. In both bone areas we observed trends of lowering BMD as the subjects BMI decreased. Subjects with osteoporosis are more prone to BMI depended BMD changes, concerning subjects with osteopenia and normal BMD. In addition, normal weight subjects compared to overweight and obese had the highest prediction coefficients of BMI-depended changes on BMD. Conclusion. High prevalence of low BMD coexists with overweight and obese elderly females in Vojvodina. Prediction equations for the calculation of BMD can be used to evaluate the effect of BMI changes on BMD in clinical settings.

Association of nutritional status with osteoporosis, sarcopenia, and cognitive impairment in patients on hemodialysis.

Inadequate nutrition in patients on hemodialysis causes various complications. This study aimed to investigate the association between nutritional status and risk of osteoporosis, sarcopenia, and cognitive impairment in patients on hemodialysis. We enrolled 131 older patients on maintenance hemodialysis. Geriatric Nutrition Risk Index (GNRI) was used to assess nutritional status. Patients were divided into quartile groups according to the GNRI. Dual-energy X-ray absorptiometry, bioimpedance analysis and handgrip strength measurement, and the Korean version of the Montreal Cognitive Assessment were used to assess osteoporosis, sarcopenia, and cognitive impairment, respectively. Biochemical laboratory tests were also performed before mid-week hemodialysis session. Patients from higher GNRI quartiles had a lower prevalence of osteoporosis and sarcopenia. Cognitive impairment was not associated with any GNRI quartile. In the multivariable models, longer dialysis periods (OR 1.696, 95% CI 1.053-2.729, p=0.030) and higher intact parathyroid hormone levels (OR 3.136, 95% CI 1.781-5.518, p<0.001) were significantly associated with osteoporosis risk. GNRI quartile 2 (OR 0.064, 95% CI 0.005-0.883, compared to quartile 1, p=0.040) and higher hemoglobin A1c levels (OR 3.728, 95% CI 1.033-86.4, p=0.043) were associated with a higher sarcopenia risk. Lower hemoglobin levels (OR 0.585, 95% CI 0.360-0.950, p=0.030) were associated with a higher risk of cognitive impairment. In patients on hemodialysis, inadequate nutrition was associated with the risk of osteoporosis and sarcopenia, but not cognitive impairment. Proper nutritional assessment and management in these patients could prevent complications related to bone and muscle loss.

CHANGES IN BONE MINERAL DENSITY AFTER TOTAL KNEE ARTHROPLASTY.

ABSTRACTObjective: We aimed to investigate the change in bone mineral density (BMD) in the first postoperative year in patients that underwent total knee arthroplasty (TKA) due to primary osteoarthritis of the knee. Methods: Preoperative and first postoperative year dual-energy X-ray absorptiometry measurements of 76 patients with knee osteoarthritis, who undergone surgery between 2016 and 2018 due to the recommendation for TKA, were statistically evaluated in the study. Results: Of the 19 patients with a normal BMD in the preoperative period, 73.7% (n = 14) continued to have a normal BMD in the postoperative period. Of the 34 patients with a low BMD (osteopenia) in the preoperative period, 91.2% (n = 31) did not show any change, whereas osteoporosis was observed in two patients (5.9%) in the postoperative period. Of the 23 patients with osteoporosis in the preoperative period, 95.7% (n = 22) did not show any change, whereas osteopenia was observed in one patient (4.3%) in the postoperative period. Both the T and Z scores of the spine (L1-L4) and proximal femur showed a slightly positive trend, however, with an insignificant statistical difference (p ≥ 0.05). Conclusion: Patients that underwent TKA experienced a statistically insignificant bone gain at the spine and proximal femur twelve months after the surgery.Level of Evidence III, Therapeutic Studies Investigating the Results of Treatment.

Body Mass Index Best Predicts Recovery of Recombinant Factor VIII in Underweight to Obese Patients with Severe Haemophilia A.

Factor VIII (FVIII) products are usually dosed according to body weight (BW). This may lead to under- or over-dosing in underweight or obese patients, respectively. This article evaluates the pharmacokinetics (PK) of recombinant FVIII concentrate, particularly recovery, in relation to body mass index (BMI) and other body composition descriptors. Thirty-five previously treated adults with severe haemophilia A from five BMI categories (underweight, normal, overweight, obese class I and II/III) were included. PK was evaluated after 50 IU per kilogram of BW single-dose recombinant FVIII (turoctocog alfa). The body composition variable was based on measurements of weight, height, bioimpedance analysis, and dual-energy X-ray absorptiometry. A dosing model was derived to achieve similar peak FVIII activity levels across BMI categories. A statistically significant positive association between BMI and C30min, IR30min, and AUC0-inf was observed; CL and Vss showed a significant negative association with BMI; t½ was independent of BMI and other parameters. The dosing model introduced a correction factor 'M' for each BMI category, based on linear regression analysis of C30min against BMI, which ranged from 0.55 for underweight to 0.39 for obese class II/III. This model achieved similar peak FVIII activity levels across BMI categories, estimating an average dose adjustment of +243.3 IU (underweight) to -1,489.6 IU (obese class II/III) to achieve similar C30min. BMI appears to be the best predictor of recombinant FVIII recovery; however, PK endpoints were also dependent on other body composition variables. The model demonstrated that dosing can be adjusted for individual BMI to achieve better FVIII predictability across BMI categories.

The association between DXA-derived body fat measures and breast cancer risk among postmenopausal women in the Women's Health Initiative.

BackgroundMost studies demonstrating an association between excess adiposity and postmenopausal breast cancer have used anthropometric measures, particularly body mass index (BMI). However, more direct body fat measures may more accurately determine the relationship between body fat distribution and breast cancer risk.MethodsCox proportional hazards regression models were created to examine the associations of dual‐energy x‐ray absorptiometry (DXA) body fat measures (at baseline and during follow‐up) with breast cancer risk among 10 931 postmenopausal women from the Women's Health Initiative cohort. A total of 639 incident invasive breast cancer cases (including 484 estrogen receptor positive (ER+) cases) were ascertained after a median follow‐up of 15.0 years.ResultsExcess whole body fat mass and trunk fat mass were positively associated with risk invasive breast cancer risk. These associations persisted even after additional adjustment for standard anthropometric measures. In time‐dependent analyses, we observed that both whole body fat mass and trunk fat mass, in the highest versus lowest category, were associated with a doubling of risk of invasive breast cancer overall (HR: 2.17; 95% CI: 1.54‐3.05 and 2.20; 1.55‐3.14, respectively) and of ER+ breast cancer (2.05; 1.37‐3.05 and 2.03; 1.34‐3.07, respectively). The remaining DXA measures were also positively associated with breast cancer risk in baseline and time‐dependent analyses.ConclusionThese findings suggest that DXA‐derived body fat measures are positively associated with breast cancer risk after adjustment for BMI and other conventional breast cancer risk factors.

Fatigue-caused damage in trabecular bone from clinical, morphological and mechanical perspectives

Bone quantity and quality are considered the main predictors of bone mechanical properties (i.e., strength and fracture resistance). These factors deal with the morphology and chemical composition of bone and can be assessed by non-invasive techniques such as dual-energy x-ray absorptiometry (DXA), providing the bone mineral density (BMD) and the trabecular bone score (TBS). These parameters, and in particular BMD, are currently used as clinical predictors of fracture risk but do not provide information regarding the fatigue life. Bone is continuously subjected to fatigue loading and fatigue-induced damage can be crucial in fragility fractures. To probe the effect of fatigue-induced damage on bone microarchitecture and elucidate the effect of such damage on the bone clinical parameters, we combined fatigue testing on ex-vivo porcine trabecular bone samples with DXA measurements and μCT imaging. In addition, we performed interrupted cyclic tests at different load levels and measured fatigue-induced damage accumulation in the form of stiffness degradation. We also highlighted the change of clinical and microstructural parameters during the accumulation of fatigue-induced damage in interrupted fatigue tests. Our results suggest that the parameters obtained from the current non-invasive diagnostic protocols (i.e. μCT and DXA) are not able to assess the amount of fatigue-induced damage. This can be due to the fact that such techniques provide global parameters, whereas fatigue-induced damage is a local phenomenon, closely connected to the microarchitecture.

A new finite element based parameter to predict bone fracture.

Dual Energy X-Ray Absorptiometry (DXA) is currently the most widely adopted non-invasive clinical technique to assess bone mineral density and bone mineral content in human research and represents the primary tool for the diagnosis of osteoporosis. DXA measures areal bone mineral density, BMD, which does not account for the three-dimensional structure of the vertebrae and for the distribution of bone mass. The result is that longitudinal DXA can only predict about 70% of vertebral fractures. This study proposes a complementary tool, based on Finite Element (FE) models, to improve the DXA accuracy. Bone is simulated as elastic and inhomogeneous material, with stiffness distribution derived from DXA greyscale images of density. The numerical procedure simulates a compressive load on each vertebra to evaluate the local minimum principal strain values. From these values, both the local average and the maximum strains are computed over the cross sections and along the height of the analysed bone region, to provide a parameter, named Strain Index of Bone (SIB), which could be considered as a bone fragility index. The procedure is initially validated on 33 cylindrical trabecular bone samples obtained from porcine lumbar vertebrae, experimentally tested under static compressive loading. Comparing the experimental mechanical parameters with the SIB, we could find a higher correlation of the ultimate stress, σULT, with the SIB values (R2adj = 0.63) than that observed with the conventional DXA-based clinical parameters, i.e. Bone Mineral Density, BMD (R2adj = 0.34) and Trabecular Bone Score, TBS (R2adj = -0.03). The paper finally presents a few case studies of numerical simulations carried out on human lumbar vertebrae. If our results are confirmed in prospective studies, SIB could be used—together with BMD and TBS—to improve the fracture risk assessment and support the clinical decision to assume specific drugs for metabolic bone diseases.

Effect of unfocused extracorporeal shockwave therapy on bone mineral content of twelve distal forearms of postmenopausal women: a clinical pilot study

SummaryExtracorporeal shockwave therapy showed a pronounced effect on bone mass in previous animal studies. We showed in this pilot study that a single treatment with unfocused shockwave therapy in unselected patients does not show side effects. Although our study did not show any effect of shockwave on BMD, the limited sample size does not definitively exclude this and a study with 174 subjects per group would be needed to show an effect size of 0.3 with a power of 80%.PurposeUnfocused extracorporeal shockwave therapy might stimulate bone formation to reduce the fracture risk. In this study, we assessed the safety of unfocused extracorporeal shockwave therapy and its effects on bone mass.MethodsA clinical pilot study with twelve female patients free of bone disease undergoing elective surgery of the lower extremity or elective spinal surgery under general anesthesia received 3.000 electrohydraulic-generated unfocused extracorporeal shockwaves (energy flux density 0.3 mJ/mm2) to one distal forearm. The contralateral forearm served as a control. We examined the effect on bone mass with the use of repeated dual energy X-ray absorptiometry measurements and we measured patient discomfort around the therapy.ResultsNo difference in bone mineral content and density was measured 6 and 12 weeks after therapy. shockwave therapy occasionally caused transient erythema or mild hematoma, but no discomfort in daily life or (late) adverse events.ConclusionsUnfocused extracorporeal shockwave therapy is a safe treatment, but no increase in bone mass on the forearm was found at 0.3 mJ/mm2 energy flux density. In this study, we were not able to demonstrate that a single treatment with unfocused shockwave therapy in unselected patients had any effect in terms of bone mineral density (BMD) or bone mineral content (BMC). A power analysis indicated that 174 patients per group are required to show an effect size of 0.3 with a power of 80%.

Novel MRI-based score for assessment of bone density in operative spine patients

BackgroundGood bone quality is key in avoiding a multitude of afflictions, including osteoporotic fragility fractures and poor outcomes after spine surgery. In patients undergoing instrumented spine fusion, bone quality often dictates screw pullout strength, insertional torque, and vertebral body loading properties. While dual-energy X-ray absorptiometry (DEXA) screening is the current method of assessing bone mineral density, the majority of patients do not have DEXA measurements available before undergoing surgical instrumentation. PurposeTo create a simple magnetic resonance imaging (MRI)-based score to evaluate bone quality and evaluate the degree to which it correlates with conventional DEXA scores. Study Design/SettingRetrospective cohort. Patient SamplePatients ≥18 years of age undergoing spine surgery for degenerative conditions between 2013 and 2018. Outcome MeasuresCorrelation of the vertebral bone quality (VBQ) score with DEXA T-scores, and association between VBQ score and presence of osteopenia/osteoporosis. MethodsUsing noncontrast T1-weighted MRIs of the lumbar spine, the novel VBQ score was calculated for each patient. DEXA T-scores of the femoral neck and total hip were obtained and were compared with patient VBQ scores using linear regression and Pearson's correlation. ResultsAmong 68 patients included in this study, 37 were found to have osteopenia/osteoporosis (T-score < −1.0) based on DEXA. A greater VBQ score was significantly associated with the presence of osteopenia/osteoporosis with a predictive accuracy of 81%. VBQ scores correlated moderately with femoral neck T-scores, the lowest overall T-scores of each patient, and correlated fairly with total hip T-scores. ConclusionsThis is the first study to correlate the novel VBQ score obtained from MRIs with DEXA T-score. We found this score to be a significant predictor of healthy versus osteopenic/osteoporotic bone with an accuracy of 81%, and found that VBQ score was moderately correlated with femoral neck and overall lowest T-score.

Children and Adolescents' Anthropometrics Body Composition from 3-D Optical Surface Scans.

This study aimed to explore the accuracy and precision of three-dimensional optical (3DO) whole-body scanning for automated anthropometry and estimating total and regional body composition. Healthy children and adolescents (n = 181, ages 5-17 years) were recruited for the Shape Up! Kids study. Each participant underwent whole-body dual-energy x-ray absorptiometry and 3DO scans; multisite conventional tape measurements served as the anthropometric criterion measure. 3DO body shape was described using automated body circumference, length, and volume measures. 3DO estimates were compared with criterion measures using simple linear regression by the stepwise selection method. Of the 181 participants, 112 were used for the training set, 49 were used for the test set, and 20 were excluded for technical reasons. 3DO body composition estimates were strongly associated with dual-energy x-ray absorptiometry measures for percent body fat, fat mass, and fat-free mass (R2 : 0.83, 0.96, and 0.98, respectively). 3DO provided reliable measurements of fat mass (coefficient of variation, 3.30; root mean square error [RMSE], 0.53), fat-free mass (coefficient of variation, 1.34; RMSE, 0.53 kg), and percent body fat (RMSE = 1.2%). 3DO surface scanning provides accurate and precise anthropometric and body composition estimates in children and adolescents with high precision. 3DO is a safe, accessible, and practical method for evaluating body shape and composition in research and clinical settings.

760. Assessment of DEXA Scan Ordering Among Infectious Disease Providers at a Large Tertiary-Care Urban Academic Center in the Midwest

BackgroundOsteoporosis is compromised bone strength that predisposes to fracture. It can be diagnosed by Dual-energy x-ray absorptiometry (DEXA) measurement of bone mineral density (BMD). Persons with HIV (PWH) are at higher risk for the development of osteoporosis. As such, the HIV Medicine Association’s (HIVMA) primary care guidelines recommend DEXA screening for all HIV-infected postmenopausal women and men aged ≥50 years. The purpose of this study was to asses the frequency of DEXA utilization within a tertiary-care urban academic center in the Midwest and to identify prevalence of osteoporosis.MethodsA representative sample PWH age ≥50 from our institution’s outpatient infectious disease (ID) clinic were included. All subjects had at least one clinic visit in the last year, were on antiretroviral therapy (ART), and virally suppressed. Unblinded chart review was performed to assess if DEXA was ordered, was DEXA ordered by an ID physician, was DEXA completed, results of DEXA, and whether patients were on a tenofovir disoproxil fumarate (TDF)-containing regimen.Results225 charts were reviewed. 186 (83%) patients were men, with a median age of 58 (range of 50–85). DEXA scans were ordered on 39 (17%) patients, 9 (23%) of which were ordered by their ID provider. Twenty-eight (72%) DEXA scans were performed. Of scans completed, 11 (39%) diagnosed osteoporosis, 15 (54%) osteopenia, and 2 (7%) showed normal BMD. Of all charts reviewed, 29 (13%) were on TDF-containing regimens. Of those individuals with diagnosed abnormal BMD (26), only 1 (4%) was on a TDF-containing regimen.ConclusionDespite HIVMA’s recommendation for osteoporosis screening in PWH, only 17% of eligible patients with well-controlled HIV in our clinic had been referred for DEXA. Of those who had undergone DEXA screening, nearly all (93%) had abnormal BMD. Further investigation is necessary to explore provider and patient barriers for osteoporosis screening in PWH.Disclosures All authors: No reported disclosures.

Association of change in muscle mass assessed by D3 -creatine dilution with changes in grip strength and walking speed.

BackgroundMuscle mass declines with age. However, common assessments used to quantify muscle mass are indirect. The D3‐creatine (D3Cr) dilution method is a direct assessment of muscle mass; however, longitudinal changes have not been examined in relation to changes in other measures of muscle mass, strength, and performance.MethodsA convenience sample of 40 men from the Osteoporotic Fractures in Men Study (mean age = 83.3 years, standard deviation = 3.9) underwent repeat assessment of D3Cr muscle mass, dual‐energy X‐ray absorptiometry (DXA) lean mass, grip strength, and walking speed at two time points approximately 1.6 years apart (2014–2016). One‐sample t‐tests and Pearson correlations were used to examine changes in DXA total body lean mass, DXA appendicular lean mass/height2, DXA appendicular lean mass/weight, D3Cr muscle mass, D3Cr muscle mass/weight, grip strength, walking speed, and weight.ResultsD3‐creatine muscle mass, D3Cr muscle mass/weight, grip strength, and walking speed all significantly declined (all P < 0.01). The change in DXA measures of lean mass was moderately correlated with changes in D3Cr muscle mass. There was no significant correlation between the change in DXA measures of lean mass and change in walking speed (all P > 0.05). The change in D3Cr muscle mass/weight was moderately correlated with change in walking speed (r = 0.33, P < .05). The change in grip strength was weakly correlated with the change in DXA measures of lean mass and D3Cr muscle mass (r = 0.19–0.32).ConclusionsThe results of our study provide new insights regarding the decline in muscle strength and D3Cr muscle mass. The D3Cr method may be a feasible tool to measure declines in muscle mass over time.

Short-term perioperative parecoxib is not detrimental to shaft fracture healing in a rat model.

ObjectivesExperimental studies indicate that non-steroidal anti-inflammatory drugs (NSAIDs) may have negative effects on fracture healing. This study aimed to assess the effect of immediate and delayed short-term administration of clinically relevant parecoxib doses and timing on fracture healing using an established animal fracture model.MethodsA standardized closed tibia shaft fracture was induced and stabilized by reamed intramedullary nailing in 66 Wistar rats. A ‘parecoxib immediate’ (Pi) group received parecoxib (3.2 mg/kg bodyweight twice per day) on days 0, 1, and 2. A ‘parecoxib delayed’ (Pd) group received the same dose of parecoxib on days 3, 4, and 5. A control group received saline only. Fracture healing was evaluated by biomechanical tests, histomorphometry, and dual-energy x-ray absorptiometry (DXA) at four weeks.ResultsFor ultimate bending moment, the median ratio between fractured and non-fractured tibia was 0.61 (interquartile range (IQR) 0.45 to 0.82) in the Pi group, 0.44 (IQR 0.42 to 0.52) in the Pd group, and 0.50 (IQR 0.41 to 0.75) in the control group (n = 44; p = 0.068). There were no differences between the groups for stiffness, energy, deflection, callus diameter, DXA measurements (n = 64), histomorphometrically osteoid/bone ratio, or callus area (n = 20).ConclusionThis study demonstrates no negative effect of immediate or delayed short-term administration of parecoxib on diaphyseal fracture healing in rats.Cite this article: G. A. Hjorthaug, E. Søreide, L. Nordsletten, J. E. Madsen, F. P. Reinholt, S. Niratisairak, S. Dimmen. Short-term perioperative parecoxib is not detrimental to shaft fracture healing in a rat model. Bone Joint Res 2019;8:472–480. DOI: 10.1302/2046-3758.810.BJR-2018-0341.R1.