Body Bone Research Articles

Effect of laparoscopic sleeve gastrectomy versus laparoscopic Roux-en-Y gastric bypass on body composition.

There is limited data with respect to body composition changes for laparoscopic sleeve gastrectomy (SG) and laparoscopic Roux-en-Y gastric bypass (RYGB). The objective of this study was to analyse changes in body composition between these two procedures during the first year after bariatric surgery. A prospective study was performed in patients undergoing bariatric surgery at two tertiary hospitals between 2017 and 2023. Body composition was assessed with dual-energy x-ray absorptiometry immediately before surgery, and at 1-, 6-, 12-, 18- and 24-months post-operatively, with a subgroup analysis performed for patients who undertook a scan at 18- and 24-months. Total weight loss (TWL), body mass index (BMI), fat mass (FM), lean body mass (LBM) and bone mineral content (BMC) parameters were compared between SG and RYGB. Forty-five patients were included in this series (SG n = 30, RYGB n = 15). There was a significant reduction in mean %TWL of 26.94 ± 8.86% and mean BMI of 11.12 ± 3.70 kg/m2 over 12-months. LBM accounted for 17.8% of TWL over 12-months, SG and RYGB did not differ in terms of loss of FM or LBM. For both procedures, the loss of LBM appeared to plateau at 6-months post-operatively. The only statistically significant finding between the two procedures was that RYGB resulted in an additional 0.06 kg loss compared with SG. SG and RYGB have been shown to have comparable weight loss and body composition changes in the short-to-medium term following surgery. LBM reduction was most significant in the early post-operative period across the entire cohort.

Incorporation of Dry Edible Beans to a High-Fat Diet Does Not Affect Body Composition and Bone Structural Parameters in Obese Mice

Incorporation of Dry Edible Beans to a High-Fat Diet Does Not Affect Body Composition and Bone Structural Parameters in Obese Mice

A cost-free approach to evaluating vertebral body bone density and height loss in lung transplant recipients using routine chest CT

BackgroundTo assess changes in bone density and vertebral body height of patients undergoing lung transplant surgery using computed tomography (CT). MethodsThis institutional review board (IRB) approved retrospective observational study enrolled patients with a history of lung transplant who had at least two chest CT scans. Vertebral body bone density (superior, middle, and inferior sections) and height (anterior, middle, and posterior sections) were measured at T1-T12 at baseline and follow up CT scans. Changes in the mean bone density, mean vertebral height, vertebral compression ratio (VBCR), percentage of anterior height compression (PAHC), and percentage of middle height compression (PMHC) were calculated and analyzed. ResultsA total of 93 participants with mean age of 58 ± 12.3 years were enrolled. The most common underlying disease that led to lung transplants was interstitial lung diseases (57 %). The inter-scan interval was 34.06 ± 24.8 months. There were significant changes (p-value < 0.05) in bone density at all levels from T3 to T12, with the greatest decline at the T10 level from 163.06 HU to 141.84 HU (p-value < 0.05). The average VBCR decreased from 96.91 to 96.15 (p-value < 0.05). ConclusionRoutine chest CT scans demonstrate a gradual decrease in vertebral body bone density over time in lung transplant recipients, along with evident anatomic changes such as vertebral body bone compression. This study shows that utilizing routine chest CT for lung transplant recipients can be regarded as a cost-free tool for assessing the vertebral body bone changes in these patients and potentially aiding in the prevention of complications related to osteoporosis.

Sex-Specific Effects of THRβ Signaling on Metabolic Responses to High Fat Diet in Mice.

Thyroid hormone (TH) plays a crucial role in regulating the functions of both bone and adipose tissue. Given that TH exerts its cholesterol-lowering effects in hepatic tissue through the TH receptor-β (TRβ), we hypothesized that TRβ agonist therapy using MGL3196 (MGL) would be effective in treating increased adiposity and bone loss in response to a 12-week high-fat diet (HFD) in adult C57BL/6J mice. Transcriptional and serum profiling revealed that HFD-induced leptin promoted weight gain in both males and females, but MGL only suppressed leptin induction and weight gain in males. In vitro studies suggest that estrogen suppresses MGL activity in adipocytes, indicating that estrogen might interfere with MGL-TRβ function. Compared to systemic adiposity, HFD reduced bone mass in male but not female mice. Paradoxically, MGL treatment reversed macroscopic bone mineral density loss in appendicular bones, but micro-CT revealed that MGL exacerbated HFD-induced trabecular bone loss, and reduced bone strength. In studies on the mechanisms for HFD effects on bone, we found that HFD induced Rankl expression in male femurs that was blocked by MGL. By ex vivo assays, we found that RANKL indirectly represses osteoblast lineage allocation of osteoprogenitors by induction of inflammatory cytokines TNFα, IL-1β, and CCL2. Finally, we found that MGL functions in both systemic adiposity and bone by nongenomic TRβ signaling, as HFD-mediated phenotypes were not rescued in TRβ147F knockout mice with normal genomic but defective nongenomic TRβ signaling. Our findings demonstrate that the negative effects of HFD on body fat and bone phenotypes are impacted by MGL in a gender-specific manner.

Normative Values for Sternoclavicular Joint and Clavicle Anatomy Based on MR Imaging: A Comprehensive Analysis of 1591 Healthy Participants.

Background: The clavicle remains one of the most fractured bones in the human body, despite the fact that little is known about the MR imaging of it and the adjacent sternoclavicular joint. This study aims to establish standardized values for the diameters of the clavicle as well as the angles of the sternoclavicular joint using whole-body MRI scans of a large and healthy population and to examine further possible correlations between diameters and angles and influencing factors like BMI, weight, height, sex, and age. Methods: This study reviewed whole-body MRI scans from the Study of Health in Pomerania (SHIP), a German population-based cross-sectional study in Mecklenburg-Western Pomerania. Descriptive statistics, as well as median-based regression models, were used to evaluate the results. Results: We could establish reference values based on a shoulder-healthy population for each clavicle parameter. Substantial differences were found for sex. Small impacts were found for height, weight, and BMI. Less to no impact was found for age. Conclusions: This study provides valuable reference values for clavicle and sternoclavicular joint-related parameters and shows the effects of epidemiological features, laying the groundwork for future studies. Further research is mandatory to determine the clinical implications of these findings.

Mendelian randomization study on association between grip strength and BMD in different age groups

IntroductionThis study aimed to use the Mendelian randomization study method to verify the causal relationship between grip strength and bone mineral density (BMD) in different ages and different parts of the body.Materials and methodsThe analysis was based on pooled data from genome-wide association studies (GWAS). Hand grip strength (right) was used as the exposure variable and total body bone mineral density (BMD) of different age groups was used as the outcome variable. Single-nucleotide polymorphisms highly correlated with exposure variables were used as instrumental variables. The inverse variance weighted (IVW) method was used as the primary analysis method, and the Mendelian randomization Egger (MR-Egger) regression and weighted median methods were used as supplementary evidence for the IVW results. Horizontal pleiotropy and heterogeneity tests were conducted to ensure the stability of the results.ResultsAnalyzing the GWAS data on osteoporosis as the outcome variable, the IVW analysis showed that osteoporosis risk was associated with decreased grip strength in the 45–60 age group and the risk of declining lumbar spine BMD was associated with decreased grip strength. However, there was no significant correlation between the risk of osteoporosis in other age groups and changes in grip strength.ConclusionA causal relationship exists between decreased grip strength and osteoporosis risk in people aged 45–60 years. The risk of BMD declining in the lumbar spine was associated with reduced grip strength.

Correlation Analysis of Body Fat Percentage, Muscle Mass, and Bone Mass with Punch Speed in Kumite Karate Athletes

Objective. Anthropometry is recognized as a significant determinant of athletic performance. Despite extensive research on anthropometric factors in conventional sports, limited attention has been given to specific martial arts disciplines, notably in elite karate athletes. Hence, this investigation seeks to explore the correlation between muscle mass, body fat percentage, bone mass, and punch speed among karate athletes. Methods. A total 15 male elite-level karate athletes participated in thsi study. Body weight, body fat percentage, bone mass, and muscle mass were assessed utilizing the Xiaomi Scale 2, whereas punch speed was gauged employing the Hykso Punch Tracker. Results. There was a positive relationship with body fat percentage of 0.679, right speed had a positive relationship with body fat percentage of 0.609, and maximal speed had a negative relationship with body fat percentage of -0.692. While the muscle mass variable shows a correlation value with a left speed of -0.687, at the right speed of -0.616, and at a maximum speed of 0.701. In addition, the bone mass variable has a correlation value with left speed of -0.734, right speed of 0.592, and maximum speed of 0.805. Conclusion. A positive correlation between body fat percentage, muscle mass, and bone mass with punch speed among karate athletes. Athletes exhibiting lower muscle mass and higher body fat tended to demonstrate slower punching speeds. Consequently, the assessment of body fat percentage, muscle mass, and bone mass emerges as a valuable tool for informing the technical aspects of training, particularly in enhancing punch speed for karate practitioners. Keywords: Body Fat, Muscle Mass, Bone Mass, Punch, Karate

Impact of high fat and low lean mass phenotype on bone mineral content: A cross-sectional study of Chinese adolescent population

Background and ObjectiveResearch on body composition phenotypes and bone health in adolescents is limited. Hence, this study aimed to analyze the relationship between different body composition phenotypes, bone mineral content, and bone metabolism markers in Chinese adolescents. MethodsIn this cross-sectional study, 1852 adolescents aged 12 to 18 years were selected from six schools in Yinchuan City between 2017 and 2020 using stratified cluster random sampling. The participant's body composition and bone mineral content (BMC) were measured using bioelectrical impedance analysis (BIA). Serum bone metabolic markers (OC, CTX, and Ca) were measured. Based on their FMI and LMI, individuals were categorized into four body composition phenotypes: low fat mass-low lean mass (LFMI-LLMI), low fat mass-high lean mass (LFMI-HLMI), high fat mass-high lean mass (HFMI-HLMI), high fat mass-low lean mass (HFMI-LLMI). ResultsThere was a statistically significant difference between the four different body composition phenotypes with BMC, CTX and Ca in boys (all P < 0.05), similar conclusions were found in girls, except the OC and CTX. After adjusting for age, gender, smoking, drinking, and others, compared with the LFMI-HLMI reference group, the two high FMI groups (HFMI-LLMI and HFMI-HLMI) had a greater negative correlation with BMC, while the low BMC risk of the HFMI-LLMI group was the highest (OR = 33.28; 95%CI: 11.12–99.63; P < 0.001). The correlation between BMC of different body composition phenotypes in boys was greater than that in girls. HFMI-HLMI is a risk phenotype negatively associated with Ca content (β = −0.12; 95%CI: −0.19 to −0.04; P < 0.05). Regardless of body composition level, BMC was always negatively correlated with fat mass (LLMI: β = −0.27; 95%CI: −0.32–0.21; HLMI: β = −0.52, 95%CI: −0.65–0.40) and positively correlated with lean mass (LFMI: β =0.24; 95%CI: 0.20–0.28; HFMI: β =0.23, 95%CI:0.13–0.33) (all P < 0.001). The fat mass showed different correlations with OC and CTX in girls and boys based on LLMI or HLMI (all P < 0.05). ConclusionHFMI-LLMI is a risk phenotype of low BMC in Chinese adolescents, and the relationship between fat mass and bone metabolism markers is affected by lean body mass and gender.

Insulin sensitivity, body composition and bone mineral density after testosterone treatment in transgender youth with and without prior GnRH agonist therapy

Background1.8% of youth identify as transgender; a growing proportion are transgender male (female sex, male gender identity). Many receive gonadotropin releasing hormone agonist (GnRHa) therapy to suppress endogenous puberty and/or will start testosterone to induce secondary sex characteristics that align with gender identity. Objective(s)To determine the effects of 12 months of testosterone on cardiometabolic health among transgender youth, including insulin sensitivity, body composition, and bone mineral density and whether changes in outcomes differ based on prior GnRHa treatment. MethodsParticipants (n = 19, baseline age 15.0 ± 1.0 years) were examined prior to and 12 months after testosterone therapy in a longitudinal observational study. Fasted morning blood draw, a 2-hour 75-gram oral glucose tolerance test, body composition and bone mineral density (dual-energy X-ray absorptiometry) were assessed at baseline and 12 months. Insulin sensitivity was estimated by HOMA-IR and Matsuda index. Changes were compared with mixed linear regression models evaluating time (baseline, 12 months), group (GnRHa treatment yes/no), and their interaction. ResultsIn the entire cohort, fasted insulin decreased (median [25,75 %ile]: −3 [-5, 0] mIU/L, p = 0.044) and 2-hour glucose increased (mean ± standard deviation): +18.5 ± 28.9 mg/dL, p = 0.013 from baseline after 12 months of testosterone therapy. There were no significant changes in HOMA-IR (p = 0.062) or Matsuda index (p = 0.096), nor by GnRHa status. Absolute (+6.2 [4.7, 7.5] kg, p = 0.016) and percent fat-free mass increased (+7.3 [5.4, 9.1] %, p = 0.003) and percent fat mass declined (−7.4 [-9.3, 5.3]%, p = 0.005) for the entire cohort. There were time*group interactions for absolute (p = 0.0007) and percent fat-free mass (p = 0.033). There were time*group interactions for bone mineral content (p = 0.006). ConclusionsTwelve months of testosterone in transgender adolescents resulted in changes in body composition and bone mineral density, with baseline differences between the +/-GnRHa group and convergence after 12 months. There were no changes in insulin sensitivity over time or between groups.

Causal relationship between sarcopenia with osteoarthritis and the mediating role of obesity: a univariate, multivariate, two-step Mendelian randomization study

BackgroundRecent genetic evidence supports a causal role for sarcopenia in osteoarthritis, which may be mediated by the occurrence of obesity or changes in circulating inflammatory protein levels. Here, we leveraged publicly available genome-wide association study data to investigate the intrinsic causal relationship between sarcopenia, obesity, circulating inflammatory protein levels, and osteoarthritis.MethodsIn this study, we used Mendelian randomization analyses to explore the causal relationship between sarcopenia phenotypes (Appendicular lean mass [ALM], Low hand-grip strength [LHG], and usual walking pace [UWP]) and osteoarthritis (Knee osteoarthritis [KOA], and Hip osteoarthritis [HOA]). Univariable Mendelian randomization (UVMR) analyses were performed using the inverse variance weighted (IVW) method, MR-Egger, weighted median method, simple mode, and weighted mode, with the IVW method being the primary analytical technique. Subsequently, the independent causal effects of sarcopenia phenotype on osteoarthritis were investigated using multivariate Mendelian randomization (MVMR) analysis. To further explore the mechanisms involved, obesity and circulating inflammatory proteins were introduced as the mediator variables, and a two-step Mendelian randomization analysis was used to explore the mediating effects of obesity and circulating inflammatory proteins between ALM and KOA as well as the mediating proportions.ResultsUVMR analysis showed a causal relationship between ALM, LHG, UWP and KOA [(OR = 1.151, 95% CI: 1.087–1.218, P = 1.19 × 10–6, PFDR = 7.14 × 10–6) (OR = 1.215, 95% CI: 1.004–1.470; P = 0.046, PFDR = 0.055) (OR = 0.503, 95% CI: 0.292–0.867; P = 0.013, PFDR = 0.027)], and a causal relationship between ALM, UWP and HOA [(OR = 1.181, 95% CI: 1.103–1.265, P = 2.05 × 10–6, PFDR = 6.15 × 10–6) (OR = 0.438, 95% CI: 0.226–0.849, P = 0.014, PFDR = 0.022)]. In the MVMR analyses adjusting for confounders (body mass index, insomnia, sedentary behavior, and bone density), causal relationships were observed between ALM, LHG, UWP and KOA [(ALM: OR = 1.323, 95%CI: 1.224- 1.431, P = 2.07 × 10–12), (LHG: OR = 1.161, 95%CI: 1.044- 1.292, P = 0.006), (UWP: OR = 0.511, 95%CI: 0.290- 0.899, P = 0.020)], and between ALM and HOA (ALM: OR = 1.245, 95%CI: 1.149- 1.348, P = 7.65 × 10–8). In a two-step MR analysis, obesity was identified to play a potential mediating role in ALM and KOA (proportion mediated: 5.9%).ConclusionsThe results of this study suggest that decreased appendicular lean mass, grip strength, and walking speed increase the risk of KOA and decreased appendicular lean mass increases the risk of HOA in patients with sarcopenia in a European population. Obesity plays a mediator role in the occurrence of KOA due to appendicular lean body mass reduction.

SKIN CANCER DETECTION USING CNN

The skin is the main component of a human body and serves to cover all of the body's muscles, bones, and other structures. Many people these days are afflicted with skin cancer. Skin cancer that is most deadly is called malignant melanoma. Melanoma is the most dangerous kind of cancer. It is a massive malignant tumour on the skin, and its spread is growing daily. If melanoma is discovered early on, treatment is straightforward. Melanoma diagnosis involves both automated and clinical procedures. Early detection of malignant melanoma has significant potential with image-based computer aided diagnosis methods. Automatically identifying the type of skin cancer from the pictures can help with a speedier diagnosis and improved accuracy.

Osteoporosis and coronary heart disease: a bi-directional Mendelian randomization study.

Osteoporosis (OP) and cardiovascular disease (CVD) are major global public health issues, especially exacerbated by the challenges of an aging population. As these problems intensify, the associated burden on global health is expected to increase significantly. Despite extensive epidemiological investigations into the potential association between OP and CVD, establishing a clear causal relationship remains elusive. Instrumental variables were selected from summary statistics of the IEU GWAS database. Five different components of BMD (heel BMD, LS BMD, FA BMD, FN BMD, and TB BMD) were used as OP phenotypes. CHD, MI, and stroke were selected to represent CVD. Multiple analysis methods were used to evaluate the causal relationship between CVD and OP comprehensively. In addition, sensitivity analyses(Cochran's Q test, MR-Egger intercept test, and "leave one out" analysis) were performed to verify the reliability of the results. The MR showed a significant causal relationship between CHD on heel BMD and TB BMD; in the reverse analysis, there was no evidence that OP has a significant causal effect on CVD. The reliability of the results was confirmed through sensitivity analysis. The study results revealed that CHD was causally associated with Heel BMD and TB BMD, while in the reverse MR analysis, the causal relationship between OP and CVD was not supported. This result posits CHD as a potential etiological factor for OP and prompts that routine bone density assessment at traditional sites (forearm, femoral neck, lumbar spine) using DAX may inadequately discern underlying osteoporosis issues in CHD patients. The recommendation is to synergistically incorporate heel ultrasound or DAX for total body bone density examinations, ensuring clinical diagnostics are both precise and reliable. Moreover, these findings provide valuable insights for public health, contributing to the development of pertinent prevention and treatment strategies.

An Intrabronchial Foreign Body Revealed by Bronchiectasis (Bone Fragment)

Tracheobronchial foreign bodies (FB) by inhalation accidental are serious incidents and particularly common in children. In adults, they are less frequent, very often unrecognized and therefore diagnostic often difficult. Passed unnoticed or neglected, these intrabronchial FBs are responsible for repeated respiratory infections, bronchectasis, which can lead to destruction of the pulmonary parenchyma. We report a case of a neglected foreign body (bone fragment) present in the bronchus of an adult for 53 years revealed by bronchopulmonary suppurations causing bronchiectasis and treated surgically.

Lipid metabolism mediates the association between body mass index change and bone mineral density: The Taizhou imaging study

BackgroundLimited research explores the impact of body mass index (BMI) change on osteoporosis, regarding the role of lipid metabolism. We aimed to cross-sectionally investigate these relationships in 820 Chinese participants aged 55–65 from the Taizhou Imaging Study. MethodsWe used the baseline data collected between 2013 and 2018. T-score was calculated by standardizing bone mineral density and was used for osteoporosis and osteopenia diagnosis. Multinomial logistic regression was used to examine the effect of BMI change on bone health status. Multivariable linear regression was employed to identify the metabolites corrected with BMI change and T-score. Exploratory factor analysis (EFA) and mediation analysis were conducted to ascertain the involvement of the metabolites. ResultsBMI increase served as a protective factor against osteoporosis (OR = 0.79[0.71–0.88], P-value<0.001) and osteopenia (OR = 0.88[0.82–0.95], P-value<0.001). Eighteen serum metabolites were associated with both BMI change and T-score. Specifically, high-density lipoprotein (HDL) substructures demonstrated negative correlations (β = −0.08 to −0.06 and − 0.12 to −0.08, respectively), while very low-density lipoprotein (VLDL) substructions showed positive correlations (β = 0.09 to 0.10 and 0.10 to 0.11, respectively). The two lipid factors (HDL and VLDL) extracted by EFA acted as mediators between BMI change and T-score (Prop. Mediated = 8.16% and 10.51%, all P-value<0.01). ConclusionBMI gain among Chinese aged 55–65 is beneficial for reducing the risk of osteoporosis. The metabolism of HDL and VLDL partially mediates the effect of BMI change on bone loss. Our research offers novel insights into the prevention of osteoporosis, approached from the perspective of weight management and lipid metabolomics.

PSV-19 Impact of precision feeding and bump feeding strategy during gestation on the performance of post-weaning pigs

Abstract The objective of this study was to evaluate the post-weaning growth performance of piglets from sows of parities 1 to 3 fed with 4 different feeding programs during gestation; Flat feeding (FF, constant concentration and feed intake), Bump feeding (BF, constant concentration and variable feed intake), precision feeding by parity (PFP, variable concentration and variable feed intake using the average weight per parity), individual precision feeding (PFI, variable concentration and variable feed intake using the weight of each sow at breeding). At weaning of each parity, five litters from each of the dietary treatments were selected and five average piglets from each of these litters were transferred to a nursery building with 20 pens. All pens received the same feeding program in 3 phases of 14 d each. Piglets were weighed at the beginning and end of each feeding phase. The quantity of feed was noted for each phase. At the end of phases 1 and 3, one piglet per pen was scanned on the DXA to assess its body lean, fat, and bone mineral composition. During phase 1, average daily gain (ADG) was greater for piglets from parity 1 sows than those from parity 2 and 3 while average daily feed intake (ADFI) and feed conversion (FC) were greater for piglets from parity 3 sows (P &amp;lt; 0.05; Table). Dietary treatments during gestation did not affect performances in phase 1. In phase 2, ADG and ADFI were greater while FC was decreased for piglets from sows of parity 2 and 3 (P&amp;lt; 0.001). Piglets from FF treatment had a greater ADG and a lesser FC (P &amp;lt; 0.05) than piglets from BF, piglets from PFP and PFI being intermediate. In phase 3, piglets from parity 2 sows and those from FF treatment had greater ADG and ADFI than piglets from PFI treatment, piglets from PFP and BF treatments being intermediate (P &amp;lt; 0.005). For all post-weaning period, piglets from parity 2 sows had greater ADG, ADFI and body weight at 42 d (P &amp;lt; 0.001) while piglets from the FF treatment had better ADG and weight at 42 d (P &amp;lt; 0.05) than those from BF and PFI (P &amp;lt; 0.05), PFP being intermediate. The lean ADG was greater for piglets from FF treatment (P &amp;lt; 0.021) than piglets from PFI, piglets from BF and PFP being intermediate. Piglets from sows of parity 2 and 3 had also greater lean ADG (P &amp;lt; 0.001). Fat ADG was also higher for piglets from parity 2 sows (P &amp;lt; 0.010) than piglets from parity 1 sows, piglets from parity 3 sows being intermediate. Piglets from parity 2 sows clearly had better post-weaning performances. The FF treatment during gestation led to better post-weaning performance, suggesting that energy or nutrient intake in early gestation affects offspring growth and development in post-weaning period.

258 Nutritional strategies allowing inorganic phosphates reduction in maintaining maximum growth performance and bone mineralization in piglets

Abstract Phosphorus (P) is an essential component for optimal maintenance of growth and bone mineralization but its inclusion in animal feed is a core concern for economic and environmental concerns in ensuring sustainability of this resource. This study aimed to test impacts of different nutritional strategies such as dietary calcium (Ca) reduction and phytase superdosing for piglets fed without inorganic phosphate. A total of 147 piglets Piétrain*(Large White*Landrace) were divided among 5 experimental diets. Three levels of digestible P were tested (0.21%, 0.27%, 0.33%) by adding monocalcium phosphate (MCP) from 1) a negative control diet (NC) without MCP, 2) a diet with 0.3 % MCP (NC+0.3 % MCP), or 3) a diet with 0.6 % MCP (NC+0.6 % MCP). Those three diets contained 250 FTU/kg of phytase and a minimum amount of phytate set at 0.27%. All dietary treatments were formulated following a constant Ca:digestible P ratio at 2.1. The other two diets were formulated with two phytase’ doses added on top of the NC diet 4) 2,000 FTU/kg (NC+2000 phy) or 5) 3,000 FTU/kg (NC+3000 phy). Piglets were weighed individually at 42, 55 and 69 d of age, and feed intake per phase was recorded per pen. Average daily gain (ADG), daily feed intake (ADFI) and feed conversion ratio (FCR) were calculated. At the end of the experiment, right metacarpal was removed from 12 animals per treatment to analyze bone mineralization. Data were submitted to an ANOVA including effects of dietary treatments and body weight at start of the trial using JMP 16.2.0. Differences among means were separated by a Student’s test and significance accepted at P &amp;lt; 0.05. Liveability % was not different between treatments. The reduction of Ca and digestible P in NC did not affect growth performance (P &amp;gt; 0.05) but reduced bone ash % compared with PC (P &amp;lt; 0.05, 30.4 % vs 34.6 %, respectively). Phytase supplementation at 2,000 and 3,000 FTU/kg improved body weight gain (28.8 kg for animals fed NC vs 30.0 kg for NC+2000 phy vs 30.2k g for NC+3000 phy, P &amp;lt; 0.05), feed efficiency (1.60 vs 1.50 for NC and NC + 3000 phy, respectively; P &amp;lt; 0.05) and bone mineralization (P &amp;lt; 0.05). This experiment confirms the benefit of reducing the Ca and concomitantly P levels in piglet feed without impairing growth performance by optimal use of phytase that also provides the ability to overcome dependence on inorganic phosphates.

127 Utilizing predictive models for bone mineral content and bone mineral density as a tool to assess dietary phosphorous

Abstract Dietary phosphorous is a necessary nutrient for bone development in pigs at all stages of its growing. Deficiencies in phosphorous decrease bone mineral content (BMC) and bone mineral density (BMD) and may be a causative of lameness. However, the normal range expected in whole body (WB) and individual bones for BMC and BMD in commercial pigs has been poorly defined. Therefore, our objectives were to 1) model normal WB bone density at multiple timepoints in wean to finish pigs, and 2) determine the extent to which individual bone (femur and 3rd metatarsal) BMC and BMD could predict WB BMC and BMD. Mixed sex pigs [Camborough (1050) x 337, PIC] were utilized and included freshly weaned ~21 d (n = 8), ~44 d of age (n = 24), ~84 d of age (n = 24) and ~154 d of age (n = 24). Pigs were individually penned. Excluding weaning age, at each age group pigs were randomly assigned to diets adequate, marginally deficient, or deficient in available phosphorus (avP) and fed for 3, 4, and 6 wk (age group 44, 84, 154, respectively). Within each age group, diets were formulated to meet nutrient and energy requirements except for avP and pigs fed ad libitum. On-test and off-test body weight (BW) and feed intake and gain to feed ratio were assessed for each age group. At the end of each feeding period, all pigs were euthanized and WB, femur (F) and 3rd metatarsal (M) BMC and BMD determined by dual X-ray absorptiometry (DXA). Data were analyzed using linear and generalized additive models that predicted response variables (BMC or BMD) as a function of BW or age. Only pigs fed adequate avP diets were used in the model fit. Pigs fed adequate avP diets increased BMD with age (0.22, 0.42, 0.84 and 1.10 g/cm2, days of age 21, 44, 84 and 154 respectively, P &amp;lt; 0.001). Within day of age 84, marginally and deficient avP diets reduced BMC and BMD by 21 to 41% (P = 0.002) and 12 to 25% (P = 0.006), respectively. Within day of age 154, marginally and deficient avP diets reduced BMC and BMD by 9% (P = 0.05) and 6 to 8% (P = 0.06), respectively. Body weight record and individual bone (F and M) BMC and BMD from pigs fed deficient avP diets were used to predict WB BMC and BMD and the mean square error of prediction was selected as a criterion to evaluate the ability of the models to detect these inadequately fed pigs. Using the selected models, pigs fed nutritionally deficient diets were detected due to 2- to 7-fold increase in MSE of predicted WBMD or WBMC compared with pigs fed adequate diets. These models can be used to assess bone development and strength in growing pigs and to infer the adequacy of avP level supplied in their diets.

257 Estimating bone mineral replenishment following phosphorus deficiency in growing pigs

Abstract Available phosphorus (avP) is essential for bone health and strength in growing pigs. Our objective was to evaluate growth performance and replenishment of bone mineral in avP deficient pigs when fed diets adequate in avP. Over a 42-d test period, mixed sex pigs [n = 48; initial body weight (BW) = 13.1 ± 0.7 kg], were randomly assigned to one of three dietary treatments consisting of two experimental periods. In period 1(28 d), 8 pens/trt (2 pigs/pen) were fed diets formulated to 0.36, 0.17 and 0.08% avP and at a total calcium to avP ratio of 2.91, 3.15 or 6.40, respectively, representing adequate, marginally deficient, or deficient avP. In period 2 (14 d), marginally deficient and deficient pigs were then fed diets formulated to be above requirement at 0.54% avP and a 2.19 Ca:avP, while the adequate pigs staying on the same period 1 diet (n = 8 pens/trt). Pig BW and pen feed disappearance were recorded during each phase to calculate average daily gain (ADG), average daily feed intake (ADFI) and feed efficiency gain to feed (G:F). At the end of each period, 1 pig per pen was removed to assess whole body, femur, and 3rd metatarsal bone mineral content (BMC) and bone mineral density (BMD) via dual-energy X-ray absorptiometry (DXA). All data were analyzed with pen as the experimental unit and the fixed effect of diet within each period. At the end of period 1, adequate avP and marginally deficient fed pigs were heavier than the deficient avP fed pigs (41.9 and 41.2 vs 33.4 kg, respectively, P &amp;lt; 0.001). Consequently, ADG and ADFI were significantly reduced as avP decreased (P &amp;lt; 0.001). Compared with the adequate avP pigs, whole body BMD was reduced by 22% and 65% in marginal and deficient avP pigs (P &amp;lt; 0.001), respectively. At the end of period 2, adequate, marginal, and deficient avP pigs weighed 53.4, 53.2 vs 43.1 kg (P &amp;lt; 0.001), respectively. Within period 2, ADG, ADFI, and G:F did not differ. However, adequate avP fed pigs continued to have a greater body BMD compared with marginal and deficient avP pigs (0.928, 0.850, and 0.732 g/cm2; P &amp;lt; 0.001), respectively. Whole body BMD and BMC increased from period 1 to peiod 2, resulting in period 2 whole body BMC accretion rates of 2.31, 23.28, and 9.30 g/d (P &amp;lt; 0.007) for deficient, marginal, and adequate diets, respectively. In conclusion, pigs fed marginally deficient avP diets reduced body BMD while pigs fed deficient avP diets reduced body BMD and performance. Following this period of deficiency, marginal deficient avP pigs recovered growth and BMC within 14 d when fed increased dietary avP. However, compared with adequate avP fed pigs, the deficient pigs only partially recovered BMC and BW within the 14-d replenishment period.

Brazil nut–enriched diet modulates bone mineral density and body composition in an experimental model of chronic kidney disease

ObjectiveThis study investigates the effects of a Brazil nut-enriched diet on body composition and bone parameters in CKD animal model. MethodsMale Wistar rats were assigned to the following groups: Sham (n=8), Nx (n=6), nephrectomized rats, and NxBN (n=6), nephrectomized rats and an enricheddiet with 5% Brazil nut. Body composition parameters were obtained by dual-energy X- ray absorptiometry (DXA). Bioclin kits determined plasmatic calcium. The femurs werecollected to determine absolute mass and length, bone mineral density, and biomechanical tests. ResultsThe NxBN group exhibited a higher total body bone mineral density (BMD) value than the Nx group (0.177±0.004g/cm2vs 0,169±0.003g/cm2; p=0.0397). No significant differences were observed regarding absolute mass, length, BMD, and biomechanical parameters in the femurs of the groups. Moreover, no significant differences were found in plasmatic calcium levels among the groups. ConclusionsBrazil-nut enriched diet modulated BMD in CKD experimental model, and further studies are demanded to understand the pathways involved in this finding.

An in silico approach to elucidate the pathways leading to primary osteoporosis: age-related vs. postmenopausal

Numerical models of bone remodelling have traditionally been used to perform in silico tests of bone loss in postmenopausal women and also to simulate the response to different drug treatments. These models simulate the menopausal oestrogen decline by altering certain signalling pathways. However, they do not consider the simultaneous effect that ageing can have on cell function and bone remodelling, and thus on bone loss. Considering ageing and oestrogen decline together is important for designing osteoporosis treatments that can selectively counteract one or the other disease mechanism. A previously developed bone cell population model was adapted to consider the effect of ageing through: (1) the decrease of TGF-β\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\upbeta$$\\end{document} contained in the bone matrix and (2) an increased production of sclerostin by non-skeletal cells. Oestrogen deficiency is simulated in three different ways: (a) an increase in RANKL expression, (b) a decrease in OPG production, and (c) an increase in the responsiveness of osteoclasts to RANKL. The effect of ageing was validated using the cross-sectional study of (Riggs et al. in J Bone Miner Res 19: 1945-1954, 2004) on BMD of trabecular bone of the vertebral body of men. The joint effect of ageing and oestrogen deficiency was validated using these same clinical results but in women. In ageing, the effect of the increasing production of sclerostin is more important than the decrease of TGF-β\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\upbeta$$\\end{document}, while the three mechanisms used to simulate the effect of oestrogen deficiency produce almost identical responses. The results show that an early menopause leads to a lower average density in the fifth decade, but after the sixth decade the average density is independent of the age at menopause. Treatment of osteoporosis with denosumab was also simulated to conclude that the drug is not very effective if started before 10 years after menopause or before age 60.