Bone Status Research Articles

POL-RISK: an algorithm for 10-year fracture risk prediction in postmenopausal women from the RAC-OST-POL study.

Fragility fractures are the major consequence of osteoporosis. Thus, fracture risk assessment is an essential part of the diagnostic process in osteoporosis. The aim of the study was to develop an algorithm for fracture risk prediction. Bone status was evaluated in a population‑basedcohort of postmenopausal women at a mean (SD) age of 66.4 (7.8) years. Subsequently, all participants were contacted by phone once a year (for 10 consecutive years) to update their history of fractures. At the end of the 10‑year follow‑up, the number of the study participants was 640, of whom 129 had a history of 190 osteoporotic fractures recorded during the study period. Statistical analysis included multistep data preprocessing, feature selection, identification of fracture risk factors, and design of the final model. Logistic regression models were fitted and used for the evaluation of variables from determined feature sets, including global fit measures, as well as individual parameters, such as the Wald statistic and P value, odds ratio, and 95% CI. The 10‑year risk for any fracture depended on the age of the patient, the number of recorded fractures after the age of 40 years, femoral neck bone mass, and the occurrence of falls during the previous year. The achieved equation was incorporated into an algorithm, available at the www.fracture‑risk.pl webpage. A fracture prediction algorithm was developed in a longitudinal study to enable calculation of the 10‑year fracture risk. Identification of patients at a high risk of fracture should be followed by implementation of appropriate treatment strategy to reduce the number of future fractures.

Toward photothermal damage detection during laser osteotomy using optical coherence tomography

Feedback systems have been utilized to reduce the possible thermal side effects of lasers for surgery by means of temperature monitoring to control irrigation systems. In this study, we investigated the potential application of optical coherence tomography as a means of detecting bone dehydration status. We investigated the penetration depth of the OCT laser and its respective relation to the hydration status of bone. A deep-learning method was utilized to differentiate between different levels of water content in bone tissue (fresh/hydrated, dehydrated, and carbonized) based on the OCT images. The proposed model achieved an accuracy of 0.912 on an independent test set, demonstrating its ability to accurately predict the state of the bone considering these three conditions. We believe this method can potentially accelerate the detection of dehydration during laser surgery, improving the safety of using lasers with real-time feedback.

Consumer Sensory Evaluation of the Impact of Bone-In Versus Boneless Cuts on Beef Palatability

Objective: The objective of this study was to determine palatability traits of beef cuts of differing bone status and quality grade.

Cone-beam computed tomography-based radiographic considerations in impacted lower third molars: Think outside the box.

This study aimed to evaluate the anatomic circle around the impacted lower third molar to show, document, and correlate essential findings that should be included in the routine radiographic assessment protocol as clinically meaningful factors in overall case evaluation and treatment planning. Cone-beam computed tomographic images of impacted lower third molars were selected according to specific inclusion criteria. Impacted teeth were classified according to their position before assessment. The adjacent second molars were assessed for distal caries, distal bone loss, and root resorption. The fourth finding was the presence of a retromolar canal distal to the impaction. Communication with the dentist responsible for each case was done to determine whether these findings were detected or undetected by them before communication. Statistically significant correlations were found between impaction position, distal bone loss, and detected distal caries associated with the adjacent second molar. The greatest percentage of undetected findings was found in the evaluation of distal bone status, followed by missed detection of the retromolar canal. The radiographic assessment protocol for impacted third molars should consider a step-by-step evaluation for second molars, and clinicians should be aware of the high prevalence of second molar affection in horizontal and mesioangular impactions. They also should search for the retromolar canal due to its associated clinical considerations.

Hypoparathyroidism due to iron overload in beta-thalassemia patients

Introduction and Aim: Beta-thalassemia is a genetic blood condition characterized by a lack of or abnormal globin chain synthesis, resulting in low hemoglobin levels needing repeated blood transfusions. Iron overload and skeletal issues are frequently observed in beta-thalassemia patients. The current study aims to assess the bone status of beta-thalassemia major patients who are on treatment with repeated blood transfusion and compare it to thalassemia patients who do not require blood transfusion. Material and Methods: In this case-control study, conducted between December 2021 and April 2022 at Al-Shams Medical Laboratory, Diayla Governorate, 150 subjects were included consisting of 100 thalassemia patients and 50 healthy individuals. Results: This study revealed that in patients with minor and moderate thalassemia, the levels of red blood and white blood cells considerably increased. Additionally, both minor and major thalassemia patients had significantly higher platelet counts, and a considerably higher iron and ferritin levels. PTH, vitamin D, calcium, and calcium phosphate levels all significantly decreased in major thalassemia patients when compared to patients with moderate thalassemia and the control group, however phosphorus levels sharply increased. Conclusion: Patients with significant thalassemia have an unstable bone profile and hence, regular bone profile monitoring is recommended. In addition, such individuals are also advised to take calcium and vitamin D supplements and receive strong nutritional support.

Bone Loss in Patients with Pancreatic Neuroendocrine Tumors.

Pancreatic diseases may affect nutritional status, which is one of the important associated factors of bone health. High prevalence of osteoporosis or osteopenia has been reported in patients with pancreatitis. The bone loss in pancreatic neuroendocrine tumors (PNETs) has not been reported. In this study, we showed the prevalence of bone loss and possible associated factors in PNET patients. A total of 91 PNET patients were included. Bone status was evaluated based on computed tomography (CT) attenuation (Housfield units, HU): >160 HU, normal bone mineral density; osteopenia, 135 HU ≤ CT value ≤ 160 HU; osteoporosis, <135 HU. Associated factors for bone loss were identified by logistic regression analyses. The average age was 55.76 years old in PNET patients. The prevalence of osteoporosis and low bone mass was 37.4% and 60.4%, respectively. Higher prevalence of osteoporosis was observed in patients older than 50 years (64.0%). Multivariate logistic analysis showed that age was an associated factor for low bone mass (odds ratio (OR) = 1.13, 95% confidence interval (CI): 1.04-1.22) and osteoporosis (OR = 1.14, 95% CI: 1.03-1.20). Diabetes was also associated with bone loss in PNET patients after adjusting with confounders (OR = 13.56, 95% CI: 1.02-132.4). Our data show that bone loss is common in patients with PNETs. Age and diabetes are associated with bone loss in PNET patients.

Circulating microRNA responses to acute whole-body vibration and resistance exercise in postmenopausal women

Evaluating alterations in circulating microRNA (c-miRNA) expression may provide deeper insight into the role of exercise in the attenuation of the negative effects of aging on musculoskeletal health. Currently, there are sparse data on c-miRNA responses to acute exercise in postmenopausal women. The purpose of this study was to characterize the effects of acute bouts of resistance exercise and whole-body vibration on expression of selected c-miRNAs in postmenopausal women aged 65-76 years (n=10). We also examined relationships between c-miRNAs and muscle strength and bone characteristics. This randomized crossover design study compared c-miRNA responses to a bout of resistance exercise (RE) (3 sets 10 reps 70% 1 repetition maximum (1RM), 5 exercises) and a bout of whole-body vibration (WBV) (5 sets 1min bouts 20Hz 3.38mm peak to peak displacement, Vibraflex vibration platform). DXA was used to measure body composition and areal bone mineral density (aBMD) of the total body, AP lumbar spine, and dual proximal femur. pQCT was used to measure tibia bone characteristics (4%, 38%, 66% sites). Blood samples were collected before exercise (Pre), immediately-post (IP), 60 minutes post (60P), 24 hours (24H), and 48 hours (48H) after exercise to measure serum miR-21-5p, -23a-3p, -133a-3p, -148a-3p (qPCR) and TRAP5b (ELISA). There was a significant modality × time interaction for c-miR-21-5p expression (p=0.019), which decreased from 60P to 24H after WBV only. TRAP5b serum concentrations significantly increased IP then decreased below Pre at 24H for both WBV and RE (p<0.01). Absolute changes in TRAP5b were negatively correlated with c-miR-21-5p fold changes (r= -0.642 to -0.724, p<0.05) for both exercise modalities. There were significant negative correlations between baseline c-miRNAs and bone status variables (r= -0.639 to -0.877, p<0.05). Our findings suggest that whole-body vibration is a sufficient mechanical stimulus for altering c-miR-21-5p expression, whereas a high intensity resistance exercise protocol did not elicit any c-miRNA responses in postmenopausal women. Increases in the bone resorption marker, TRAP5b, were associated with greater downregulation of c-miR-21-5p expression.

Dietary Diversity, Micronutrient Adequacy and Bone Status during Pregnancy: A Study in Urban China from 2019 to 2020.

Diet quality during reproduction is crucial to maternal and infant health. However, the association between dietary diversity and bone health of pregnant women remains unclear. We aimed to evaluate the dietary quality of Chinese urban gravidas using the dietary diversity score (DDS), and to explore the relationship of the DDS with micronutrient adequacy and bone health. In this cross-sectional study, we analyzed data from 775 pregnant women aged 18 years or older in urban China. Dietary diversity was assessed using the Minimum Dietary Diversity for Women (MDD-W) indicator. A 24-h dietary recall was used to collect diet data and to calculate the MDD-W and the nutrient intake. Bone health was measured using quantitative ultrasound and assessed by the speed of sound (SOS). Pearson's correlation coefficients between the DDS and the nutrient adequacy ratio (NAR) were calculated. A multivariable linear regression model was used to estimate the effect size of the DDS on the SOS. The mean DDS was 6.61 ± 1.53 points and 91.0% of participants reported the consumption of five or more food groups. Women in the diverse diet subgroup (DDS ≥ 7 points) were more likely to consume all kinds of food except starchy staples and had higher NARs. Pearson's correlation coefficients between the DDS and the NAR ranged from 0.161 to 0.484. For participants in the second trimester, those with a diverse diet had a higher SOS. A multivariable linear regression analysis showed that the DDS was positively and significantly associated with the SOS (β = 17.18, 95% CI = 5.97-28.39, p = 0.003), but this was not the case for women in the first and third trimesters. Urban Chinese women had good dietary diversity during pregnancy. A higher dietary diversity was associated with a higher NAR. From the point of view of bone, a diverse diet was positively correlated with better bone status, suggesting the importance of improving diet diversity for pregnant women, especially from mid-pregnancy.

Trabecular bone score and sclerostin concentrations in patients with primary adrenal insufficiency

Patients with primary adrenal insufficiency need lifelong replacement therapy with glucocorticoids and mineralocorticoids, which may influence their bone quality. The aim of the study was to evaluate densitometry parameters, trabecular bone score and sclerostin concentrations in patients with primary adrenal insufficiency in comparison to control group. We included 29 patients (62% females) with diagnose of autoimmune primary adrenal insufficiency (mean age 49.7 ± 11.7 years, mean duration of the disease 13.2± 13.6 years) and 33 healthy subjects (adjusted with age, sex and body mass index). Bone mineral density at the femoral neck, lumbar spine, total body and trabecular bone score were evaluated. Serum sclerostin concentrations were measured. There were no significant differences in densitometry parameters (T-score, Z-score, bone mineral density in all locations) as well as in trabecular bone score in patients with adrenal insufficiency in comparison to control group. Mean serum sclerostin concentration was significantly higher in patients with adrenal insufficiency than in control group (44.7 ± 23.5 vs 30.7 ± 10.4 pmol/l, p=0.006). There was a negative correlation between trabecular bone score and the duration of adrenal insufficiency and age, also a negative correlation between femoral neck and total densitometry parameters and 24-hour urine cortisol as a marker of hydrocortisone daily dose in patients with adrenal insufficiency. The bone status in patients with primary adrenal insufficiency was not impaired in comparison to control group, while sclerostin concentration was higher. The duration of the disease and higher hydrocortisone doses may affect negatively bone status.

PSUN286 A Rare Case of Non-Islet Cell Tumor Hypoglycemia in Young Female With Metastatic Neuroendocrine Tumor

Abstract Background Non-islet cell tumor hypoglycemia (NICTH) is a rare paraneoplastic syndrome caused by a benign or cancerous tumor that over-secretes various hormones that lead to hypoglycemia. Multiple etiologies were described in literature, the most common of them is abnormal secretion of insulin-like growth factor-2 (IGF-2) known as Doege-Potter syndrome (first described in 1929). Other etiologies include oversecretion of proinsulin, IGF-1, and somatostatin. Estimated incidence of NICTH is one per one million person-years. Tumors of mesenchymal origin are most often described in association with NICTH. Laboratory diagnosis of fasting hypoglycemia associated with serum insulin levels below 3 μU/ml confirm the diagnosis of NICTH. In the case of Doege-Potter syndrome, lab findings show low levels of insulin, c-peptide, IGF-1 and a high IGF-2: IGF-1 ratio, which indicate non-insulin-mediated hypoglycemia due to IGF-2 oversecretion. Neuroendocrine tumors presented with NICTH are rare and only described in several case reports. Clinical Case We report a case of a 34 year old female with metastatic neuroendocrine high grade tumor (WHO grade 3, non small cell, diagnosed 3 years prior to presentation) with metastasis to the bone (status post debulking and radiation) and brain (status post radiation therapy). Patient was admitted due to left ankle cellulitis. Endocrinology was consulted due to incidental finding of hypoglycemia serum glucose of 44 mg/dL. Repeat serum levels showed c-peptide 1 ng/dL (normal 1.1 - 4.4) and glucose of 54 mg/dL. She denied a history of diabetes mellitus, alcohol intake, insulin or sulfonylurea use. She had normal renal and liver function. Continuous infusion of D10 started and after 24 hours the patient's hypoglycemia improved. However, hypoglycemia recurred every morning. Following morning hypoglycemia repeat serum labs showed insulin 1.3 (Normal 2.6-24.9), c-peptide 0.9 ng/dL, and serum glucose of 114 mg/dL confirming that her hypoglycemia was not insulin induced. She was not on any medications known to cause hypoglycemia. CT abdomen without contrast showed left upper quadrant heterogeneous hypoattenuating mass with calcifications, measuring approximately 8.5 cm×10.1 cm×2.6 cm. Conclusion This is a case of a patient with a high grade non small cell metastatic neuroendocrine tumor who presented with NICTH. This is the first case of a neuroendocrine tumor with non-small cell pathology causing NICTH that has been described to-date. Based on the patient's clinical presentation and available laboratory findings with recurrent fasting hypoglycemia, low insulin and c-peptide levels we confirmed diagnosis of NICTH. This patient`s hypoglycemia was most likely induced by IGF-2 overexpression (Doege-Potter syndrome) which is the most common cause of NICTH. Presentation: Sunday, June 12, 2022 12:30 p.m. - 2:30 p.m.

Predicting Bone Health Using Machine Learning in Patients undergoing Spinal Reconstruction Surgery.

Retrospective study of data collected prospectively. The goal of this study is to create a predictive model of preoperative bone health status in adult patients undergoing adult spinal reconstructive (ASR) surgery using machine learning (ML). Despite understanding that bone health impacts spine surgery outcomes, spine surgeons lack the tools to risk stratify patients preoperatively to determine who should undergo bone health screening. An ML approach mines patterns in data to determine the risk for poor bone health in ASR patients. Two hundred and eleven subjects over the age of 30 with dual energy X-ray absorptiometry scans, who underwent spinal reconstructive surgery were reviewed. Data was collected by manual and automated collection from the electronic health records. The Weka software was used to develop predictive models for multiclass classification of healthy, osteopenia, and osteoporosis (OPO) bone status. Bone status was labeled according to the World Health Organization (WHO) criteria using dual energy X-ray absorptiometry T scores. The accuracy, sensitivity, specificity, and area under the receiver operating curve (AUC) were calculated. The model was evaluated on a test set of unseen data for generalizability. The prevalence of OPO was 23.22% and osteopenia was 52.61%. The random forest model achieved optimal performance with an average sensitivity of 0.81, specificity of 0.95, and AUC of 0.96 on the training set. The model yielded an averaged sensitivity of 0.64, specificity of 0.78, and AUC of 0.69 on the test set. The model was best at predicting OPO in patients. Numerous patient features exhibited predictive value, such as body mass index, insurance type, serum sodium level, serum creatinine level, history of bariatric surgery, and the use of medications such as selective serotonin reuptake inhibitors. Predicting bone health status in ASR patients is possible with an ML approach. Additionally, data mining using ML can find unrecognized risk factors for bone health in ASR surgery patients.

Comparison of quantitative ultrasonography and dual X-ray absorptiometry for bone status assessment in South African children living with HIV.

Children living with HIV (CLHIV) have decreased bone mineral content (BMC) and density (BMD), increasing risk for fracture and future osteoporosis. While DXA is the gold-standard for bone assessments, it lacks availability in resource-constrained settings (RCS). Quantitative ultrasound (QUS) offers an alternative owing to its portability, low cost, ease of handling, and lack of ionizing radiation. While QUS has detected reduced bone quality in CLHIV, the relationship between QUS and DXA in this population remains unexplored. At baseline and 12 months, BMC and BMD of the whole body, lumbar spine, and radius were measured by DXA in a longitudinal cohort of CLHIV in Johannesburg, South Africa. Calcaneal speed of sound (SOS) and broadband ultrasound attenuation (BUA) and radius SOS were obtained by QUS, and calcaneal stiffness index (SI) was calculated. Spearman correlations, with and without HIV stratification, were performed between QUS and DXA measurements at each visit and for absolute difference in measurements between visits. At baseline and 12-months, calcaneal BUA and SI displayed strong positive correlations with DXA, with only modest correlations between radial QUS and DXA at baseline. Longitudinal measures of QUS did not correlate with DXA. At both baseline and 12-months, individuals with DXA whole-body BMD z-score < -1 displayed significantly lower calcaneal BUA and SI. Cross-sectionally, calcaneal QUS correlates strongly with whole body DXA and may represent a viable diagnostic alternative in RCS. Longitudinally, the two methods do not correlate well, possibly reflecting that each method assesses distinct aspects of bone architecture.

Progress on measurement of tibial posterior slope and its biomechanical relationship with posterior cruciate ligament

The most reliable and convenient measurement method of tibial posterior slope(TPS) and its biomechanical relationship with posterior cruciate ligament (PCL) are still controversial. For X-ray measurement, it is recommended to use full-length lateral X-ray of the lower extremity in quatrous section, which has advantage of highly repeatable and common in the daily diagnosis and treatment process, but it is only applicable to patients with tibial rotation within 15°. When the rotation exceeds 30°, it is difficult to identify the inner contour of platform and is no applicable. If it is only used for daily diagnosis and treatment evaluation, when tibial rotation angle is less than 15°, lateral knee X-ray also has a certain reference significance, but the accuracy could not meet requirements of higher clinical research. For CT measurement method, it could correct tibial rotation, but using the fitting point to measure tibial posterior slope on three-dimensional CT reconstruction is only applicable to knee joint without degeneration, more osteophyte affects the way of using fitting point to determine the plane of tibia with real tibia platform conformity degree, have some limitations. For measurement of MRI, it could not only correct tibial rotation, but also minimize the effect of osteophytes by using tibial anatomical axis as the reference axis, which is a good measurement method. For the biomechanical relationship between tibial posterior slope and tibial posterior slope, increased tibial posterior slope indirectly alleviates tension of PCL through tibial anterior displacement or directly reduces load on posterior cruciate ligament in tibial osteotomies, suggesting a protective mechanism for tibial posterior slope;in total knee arthroplasty with cruciate ligament preserved, the size of tibial posterior slope will affect roll back mechanism of femur. When affected knee with PCL injury, it should be avoid to release then aggravate injury, and the stress could be alleviated by increasing tibial posterior slope appropriately. There has been no unified conclusion on the range of tibial posterior slope that is most beneficial to PCL. The natural tibial posterior slope is between 7 ° and 10°, which is considered to be the most beneficial to protection of PCL, but further studies are needed according to the differences in patients' bone status, surgical methods and so on.

Evaluation of the impact of bone-in versus boneless cuts on beef palatability

Palatability traits of ribeye, strip loin, andtenderloin steaks were evaluated in a bone-in versus boneless scenario. Eatingquality of these cuts was also evaluated in a high quality (upper 2/3 USDAChoice) and a lower quality (USDA Select) product to evaluate the interactionsof marbling level and bone state. Subprimals were collected from both sides of12 beef carcasses per quality grade and aged for 28-d. Product was fabricatedinto 2.5-cm thick steaks and designated for either trained sensory analysis,consumer sensory analysis, Warner-Bratzler Shear Force (WBSF), or fat andmoisture determination. Results from trainedsensory analysis showed bone-in tenderloins and bone-in ribeyes as moreflavorful (P &amp;lt; 0.05) than boneless cuts from the same muscle. Bonestate had no effect (P &amp;gt; 0.05) on trained sensory initial juiciness,myofibrillar tenderness, and overall tenderness scores, or WBSF for any cut.Furthermore, tenderloin samples were rated higher (P &amp;lt; 0.05) bytrained sensory panelists for myofibrillar and overall tenderness than striploin and ribeye steaks, which were similar (P &amp;gt; 0.05). Bone state hadno impact (P &amp;gt; 0.05) on consumer tenderness and flavor ratings forany of the three cuts. But, bone-in strip loin samples were rated juicier andhigher (P &amp;lt; 0.05) overall than boneless strip loin steaks byconsumers. Tenderloin steaks were juicier, more tender, more flavorful, andrated higher overall (P &amp;lt; 0.05) than ribeyes and boneless strip loinsteaks by consumers. Moreover, there were no differences (P &amp;gt; 0.05)between strip loins and ribeyes for flavor liking by consumers and nodifference (P &amp;gt; 0.05) in overall liking rating between ribeyes andboneless strip loin steaks. Overall, bone status had a minimal impact on beefpalatability traits, providing evidence that eating quality is not greatlyimpacted by bone status for any of the cuts evaluated.

The Positive Association between Muscle Mass and Bone Status Is Conserved in Men with Diabetes: A Retrospective Cross-Sectional and Longitudinal Study.

Bone and muscle are known to be correlated and interact chemically each other. Diabetes affects the health status of these two types of organ. There has been lack of studies of men on this topic. This study aims to investigate the relationship between bone and muscle status in men with and without diabetes. This study enrolled 318 and 88 men with and without diabetes, respectively, between April 2007 and December 2017. The appendicular skeletal muscle index (ASMI) was correlated with femoral neck bone mineral density (BMD), total hip BMD, and the trabecular bone score (TBS) in both groups (p < 0.001–0.008). In analysis of the changes in muscle mass and bone-related parameters over the 3 years, the ASMI was correlated with total hip BMD only in diabetes group (p = 0.016) and the TBS in both groups (p < 0.001–0.046). This study showed that the positive correlation between muscle mass and bone status was largely conserved in diabetic group in men. Moreover, in a long-term perspective, muscle mass might be more correlated with the bone microarchitecture or bone quality than bone density, and the association between muscle mass and total hip BMD could be stronger in the diabetic group.

A single-centre study on predictors and determinants of pubertal delay and growth impairment in Epidermolysis Bullosa.

BackgroundDelayed puberty is a possible complication of Epidermolysis Bullosa (EB), though the actual incidence is still unknown. In chronic illnesses delayed puberty should be correctly managed since, if untreated, can have detrimental effects on adult height attainment, peak bone mass achievement and psychological health.Aims and methodsThis is a single-centre study on pubertal development, growth and bone status in EB. Auxological, densitometric (areal Bone Mineral Density-aBMD Z-score, Bone Mineral Apparent Density-BMAD Z-score, Trabecular Bone Score-TBS and Bone Strain Index-BSI at Lumbar spine) and body composition data (Total Body DXA scans) were collected. Disease severity was defined according to Birmingham Epidermolysis Bullosa Severity (BEBS) score.ResultsTwenty-one patients (12 Recessive Dystrophic EB-RDEB, 3 Dominant Dystrophic EB, 3 Junctional EB-JEB, 2 EB Simplex and one Kindler EB) aged 13 years (females) or 14 years (males) and above were enrolled (age 16.2±2.5 years, M/F 11/10). Short stature was highly prevalent (57%, mean height -2.12±2.05 SDS) with 55% patients with height <-2SD their mid-parental height. 7/21 patients (33%, 6 RDEB and 1 JEB) had delayed puberty with a median BEBS of 50 (range 29 to 63), a height SDS of -2.59 SDS (range -5.95 to -2.22) and a median lumbar BMAD Z-score of -4.0 SDS (range -5.42 to -0.63 SDS). Pubertal status was negatively associated with BEBS, skin involvement, inflammatory state and positively with height SDS and BMI SDS.ConclusionsPubertal delay is highly prevalent in EB, especially in patients with RDEB and JEB, high severity score and inflammatory state. Moreover, pubertal delay worsens growth impairment and bone health. A study on pubertal induction is ongoing to enlighten possible beneficial effects on adult height attainment and peak bone mass accrual.

Bone status and renal transplantation

Renal transplant is the organ transplant of a kidney into a patient with end-stage kidney disease (ESRD). It is important to regularly monitor the new kidney's function by measuring serum creatinine and other laboratory measurements at least every three months for the rest of the person's life. The pathophysiology underlying bone disorders after transplantation are resulted from a complex interplay of factors. Current review aims to investigate the bone status of the patients after renal transplant by evaluating their physical and clinical bone tests( PTH ,vit D3,ALP,Ca,P,Mg and DEXA scan). The clinical utility of serum markers of bone turnover . para thyroid hormone levels drop by half in the first six months following transplantation, but remain elevated in almost half of kidney transplant patients two years later. Levels of 1,25–dihydroxy vitamin D [1,25(OH)2D] have been linked to improved kidney function. After kidney transplantation, serum calcium generally follows a biphasic pattern. After 3-6 months after transplantation, hypercalcemia has been recorded in about 5%–15% of patients. Hypophosphatemia is frequent in the early post–transplant period, with 50% of acute kidney transplant patients experiencing it.

202. Association of MRI-based spinal muscle parameters and vertebral bone quality score in lumbar fusion patients

<h3>BACKGROUND CONTEXT</h3> Pathophysiological conditions during aging can affect bone and muscle simultaneously, such as in osteosarcopenia. The vertebral bone quality (VBQ) score based on magnetic resonance imaging (MRI) was recently introduced as a novel measure of bone quality in the lumbar spine and shown to be a significant predictor of healthy versus osteopenic/osteoporotic bone. However, the association between quantitative lumbar spinal muscle parameters and the VBQ score, is unknown. <h3>PURPOSE</h3> This study aimed to assess possible associations between the functional cross-sectional area (FCSA) of psoas and lumbar spine extensor muscles (multifidus and erector spinae) and the VBQ score. <h3>STUDY DESIGN/SETTING</h3> Retrospective cohort study. <h3>PATIENT SAMPLE</h3> Patients who underwent open posterior lumbar fusion for degenerative conditions between 2014 and 2017 at a single academic institution and had both a lumbar MRI and a computed tomography (CT) scan within 6 months prior to surgery were included. <h3>OUTCOME MEASURES</h3> FCSA and VBQ score. <h3>METHODS</h3> MRI measurements included psoas and combined multifidus and erector spinae (paraspinal) FCSA at the L3-L5 superior endplate. Following manual segmentation of muscles on axial T2-weighted images using ITK-SNAP (version 3.8), the FCSA was calculated using a custom written program on Matlab (version R2019a, The MathWorks, Inc.) that used an automated pixel intensity threshold method to differentiate between fat (high intensity) and muscle (low intensity). VBQ measurements included the signal intensity of the medullary portion of the vertebrae L1-L4 and the cerebrospinal fluid (CSF) at L3 on mid-sagittal T1-weighted MR images. The VBQ score was calculated by dividing the median signal intensity L1-L4 through the signal intensity of the CSF. Lumbar volumetric bone mineral density (vBMD) was assessed by quantitative CT using the L1/2 average, categorizing patients with a vBMD of <120 mg/cm³ as osteopenic/osteoporotic. All analyses were stratified by biological sex. Sperman correlation and multivariate linear regression analysis with adjustments for age and body mass index (BMI) were performed. <h3>RESULTS</h3> Eighty patients (58.8% female) were included in the analysis. The patient population was 93.8% Caucasian with a median age at surgery of 68.8 years. The prevalence of chronic low back pain >12 weeks was 83.8%, and the prevalence of osteopenia/osteoporosis was 65%, with no significant differences between men and women. All muscle measurements were significantly greater in men. The mean (SD) VBQ score was significantly smaller in men, at 2.26 (0.45) versus women at 2.59 (0.39) (p = 0.001). In men, a significant negative correlation was seen between psoas FCSA at L3-5 and the VBQ score, with correlation coefficients ranging from -0.487 to -0.405. After adjusting for age and BMI, a significant negative association was seen between psoas FCSA at L3 and the VBQ score in men (β = -0.373; 95% CI -0.687 - -0.058; p = 0.022). In women, there was a significant negative correlation between paraspinal FCSA at L3 and the VBQ score, with a correlation coefficient of -0.367 (p = 0.011), but no significant association was seen in the adjusted analysis. <h3>CONCLUSIONS</h3> We found the VBQ score to be negatively associated with psoas FCSA at L3 among male individuals, irrespective of age and BMI. Our results highlight sex differences in the VBQ score that were not demonstrated by vBMD or categorial bone status, and suggest a potential role of this novel measure to assess not only bone quality, but also spinal muscle quantity. Further studies are needed to assess the clinical utility of the VBQ score as a non-invasive screening tool for osteosarcopenia. <h3>FDA DEVICE/DRUG STATUS</h3> This abstract does not discuss or include any applicable devices or drugs.

Analysis of microstructural parameters of trabecular bone based on electrical impedance spectroscopy and deep neural networks

The potential of electrical impedance spectroscopy (EIS) was demonstrated for the investigation of microstructural properties of osseous tissue. Therefore, a deep neural network (DNN) was implemented for a sensitive assessment of different structural features that were derived on the basis of dielectric parameters, especially relative permittivities, recorded over a frequency range from 40 Hz to 5 MHz. The advantages of the developed method over conventional approaches, including equivalent circuit models (ECMs), linear regression and effective medium approximation (EMA), is the comprehensive quantification of bone morphologies by several microstructural parameters simultaneously, such as bone volume fraction (BV/TV), bone surface-volume-ratio (BS/BV), structure model index (SMI), trabecular number (Tb.N) and trabecular thickness (Tb.Th). The comparison of predictions of the DNN with an analysis of µCT-images confirmed a high accuracy for different microstructural parameters, which was indicated by corresponding Pearson correlation coefficients, especially for Tb.Th (r = 0.89) and BS/BV (r = 0.80). Concurrently, the approach was able to unambiguously discriminate anatomically similar bone regions (femoral head, greater trochanter and femoral neck) and therefore was capable to determine the morphological status of osseous tissue in detail. The classification was more discriminative than one based on classical linear discriminant analysis (LDA), due to the distinguishing features extracted by the DNN model. Accordingly, the method and model can serve as a potential tool for evaluating bone quality and bone status.

Association of amino acid metabolites with osteoporosis, a metabolomic approach: Bushehr elderly health program

Amino acids are the most frequently reported metabolites associated with low bone mineral density (BMD) in metabolomics studies. We aimed to evaluate the association between amino acid metabolic profile and bone indices in the elderly population. 400 individuals were randomly selected from 2384 elderly men and women over 60years participating in the second stage of the Bushehr elderly health (BEH) program, a population-based prospective cohort study that is being conducted in Bushehr, a southern province of Iran. Frozen plasma samples were used to measure 29 amino acid and derivatives metabolites using the UPLC-MS/MS-based targeted metabolomics platform. We conducted Elastic net regression analysis to detect the metabolites associated with BMD of different sites and lumbar spine trabecular bone score, and also to examine the ability of the measured metabolites to differentiate osteoporosis. We adjusted the analysis for possible confounders (age, BMI, diabetes, smoking, physical activity, vitamin D level, and sex). Valine, leucine, isoleucine, and alanine in women and tryptophan in men were the most important amino acids inversely associated with osteoporosis (OR range from 0.77 to 0.89). Sarcosine, followed by tyrosine, asparagine, alpha aminobutyric acid, and ADMA in women and glutamine in men and when both women and men were considered together were the most discriminating amino acids detected in individuals with osteoporosis (OR range from 1.15 to 1.31). We found several amino acid metabolites associated with possible bone status in elderly individuals. Further studies are required to evaluate the utility of these metabolites as clinical biomarkers for osteoporosis prediction and their effect on bone health as dietary supplements.