Femoral Neck Bone Mineral Content Research Articles

Potential Effects of an Exoskeleton-Assisted Overground Walking Program for Individuals With Spinal Cord Injury Who Uses a Wheelchair on Imaging and Serum Markers of Bone Strength: Pre-Post Study.

As many as 60% of individuals use a wheelchair long term after a spinal cord injury (SCI). This mode of locomotion leads to chronic decline in lower-extremity weight-bearing activities and contributes to the development of severe sublesional osteoporosis and high rates of fragility fracture. Overground exoskeleton-assisted walking programs provide a novel opportunity to increase lower-extremity weight bearing, with the potential to improve bone health. The aim of the study is to measure the potential effects of an exoskeleton-assisted walking program on lower-extremity bone strength and bone remodeling biomarkers in individuals with chronic (≥18 months) SCI who use a wheelchair. In total, 10 participants completed a 16-week exoskeleton-assisted walking program (34 individualized 1-hour sessions, progressing from 1 to 3 per week). Bone mineral density and bone strength markers (dual-energy x-ray absorptiometry: total body, left arm, leg, total hip, and femoral neck and peripheral quantitative computed tomography: 25% of left femur and 66% of left tibia) as well as bone remodeling biomarkers (formation=osteocalcin and resorption=C-telopeptide) were measured before and after intervention and compared using nonparametric tests. Changes were considered significant and meaningful if the following criteria were met: P<0.1, effect size ≥0.5, and relative variation >5%. Significant and meaningful increases were observed at the femur (femoral neck bone mineral content, bone strength index, and stress-strain index) and tibia (cortical cross-sectional area and polar moment of inertia) after the intervention (all P<.10). We also noted a decrease in estimated femoral cortical thickness. However, no changes in bone remodeling biomarkers were found. These initial results suggest promising improvements in bone strength markers after a 16-week exoskeleton-assisted walking program in individuals with chronic SCI. Additional research with larger sample sizes, longer interventions (possibly of greater loading intensity), and combined modalities (eg, pharmacotherapy or functional electrical stimulation) are warranted to strengthen current evidence. ClinicalTrials.gov NCT03989752; https://clinicaltrials.gov/ct2/show/NCT03989752. RR2-10.2196/19251.

Association of bone mineral density and potential risk factors for osteoporosis in patients with severe haemophilia A.

In people with haemophilia (PWH), recurrent episodes of bleeding lead to joint deterioration and bone resorption. To date, the effects of various other factors on bone mineral density (BMD) reduction have found conflicting results. The aim of this study was to analyse the relationships between BMD, bone mineral content (BMC), and trabecular bone score (TBS) parameters based on the dual X-ray absorptiometry method (DXA) and potential risk factors for osteoporosis in patients with severe haemophilia A. Fifty-five men with severe haemophilia A, aged 18-68 years, and 59 healthy volunteer men were enrolled in this study. Densitometric-derived lumbar spine and femoral neck BMD, BMC, and TBS were measured. Blood analyses were performed for morphology parameters, liver and kidney function parameters, and viral status. Serum levels of oestradiol (E2 ), testosterone (T), dehydroepiandrosterone sulphate (DHEA-S), parathormone, and vitamin D were measured. Patients showed significantly lower BMD compared to controls (p<.003). The result below the expected range for age was nearly double (6.82%vs. 3.92%) in PWH under 50 years old compared to controls. Haemophilic patients also exhibited significantly higher vitamin D3 deficiency (p<.0001), which was strongly associated with low TBS. Additionally, low body mass index and high neutrophil/lymphocyte ratio were correlated with low BMC and BMD. This study confirms the prevalence of low BMD and BMC in patients with haemophilia in Poland. Factors that contribute to low BMD are primarily vitamin D deficiency, low BMI, high neutrophil/lymphocyte ratio, and low testosterone/oestradiol ratio.

The effects of dairy product supplementation on bone health indices in children aged 3 to 18 years: A meta-analysis of randomized controlled trials.

Childhood and adolescence are critical periods for optimizing skeletal growth. Dairy products are valuable sources of bone-beneficial nutrients, particularly calcium and protein. A random-effects meta-analysis of published randomized controlled trials (RCTs) was performed to quantitatively assess the effects of dairy supplementation on bone health indices in children and adolescents. The PubMed and Web of Science databases were searched. Dairy supplementation increased whole-body bone mineral content (BMC) (+25.37 g) and areal bone mineral density (aBMD) (+0.016 g/cm2), total hip BMC (+0.49 g) and aBMD (+0.013 g/cm2), femoral neck BMC (+0.06 g) and aBMD (+0.030 g/cm2), lumbar spine BMC (+0.85 g) and aBMD (+0.019 g/cm2), and height (0.21 cm). When expressed as a percentage difference, whole-body BMC was increased by 3.0%, total hip BMC by 3.3%, femoral neck BMC by 4.0%, lumbar spine BMC by 4.1%, whole-body aBMD by 1.8%, total hip aBMD by 1.2%, femoral neck aBMD by 1.5%, and lumbar spine BMD by 2.6%. Dairy supplementation increased serum IGF-1 concentrations (19.89 nmol/l) and reduced concentrations of urinary deoxypyridinoline (-1.78 nmol/mmol) and serum PTH (-10.46 pg/ml) but did not significantly affect the serum concentrations of osteocalcin, bone alkaline phosphatase, and C-terminal telopeptide of type 1 collagen. Serum 25(OH)D concentrations (+4.98 ng/ml) increased with vitamin D-fortified dairy supplementation. The positive effects on bone mineral mass parameters and height were generally consistent across subgroups defined by gender, geographical region, baseline calcium intake, calcium from the supplementation, trial duration, and Tanner stages. In summary, dairy supplementation during growth leads to a small but significant increase in bone mineral mass parameters, and these findings are generally supported by the changes in several biochemical parameters related to bone health.

Bone mineral density and its relationship with ground reaction force characteristics during gait in young adults with Prader-Willi Syndrome

IntroductionThe incidence of osteopenia and osteoporosis is of concern in adults with Prader-Willi syndrome (PWS). Walking generates reaction forces that could stimulate bone mineralization and is popular in people with PWS. This study compared bone parameters and ground reaction forces (GRF) during gait between young adults with PWS and without PWS and explored associations between bone and GRFs during gait. Methods10 adults with PWS, 10 controls with obesity (OB) and 10 with normal weight (NW) matched on sex participated. Segmental and full body dual-energy x-ray absorptiometry scans provided femoral neck, spine, total body minus the head bone mineral density (BMD), bone mineral content (BMC). Vertical GRF, vertical impulse, posterior force and negative impulse were measured during 5 walking trials at a self-selected speed along a 10 m runway. ResultsMultivariate analyses of variance showed that adults with PWS (n = 7–8) had hip and body BMD and BMC comparable (p > .050) to NW and lower (p < .050) than OB. Adults with PWS showed slower speed than NW (p < .050) but similar to OB (p > .050). Adults with PWS presented lower absolute vertical GRF, vertical impulse and negative impulse than OB (p < .050). Pearson r correlations (p < .050) in those with PWS (n = 7–8) indicated that femoral neck BMC was associated with vertical GRF (r = 0.716), vertical impulse (r = 0.780), posterior force (r = −0.805), and negative impulse (r = −0.748). Spine BMC was associated with speed (r = 0.829) and body BMD was associated with speed (r = 0.893), and posterior force (r = −0.780). ConclusionsIncreased BMC in the femoral neck and body were associated with larger breaking forces during walking, a phenomenon normally observed at greater gait speeds. Faster walking speed was associated with greater BMC in the spine and body. Our preliminary results suggest that young adults with PWS could potentially benefit from faster walking for bone health; however, larger prospective studies are needed to confirm this.

Phase angle as a key marker of muscular and bone quality in community-dwelling independent older adults: A cross-sectional exploratory pilot study

The aim of the present cross-sectional exploratory pilot study was to analyze the ability of the Phase Angle (PhA) to predict physical function, muscle strength and bone indicators, upon adjusting for potential confounders [age, sex, lean mass, and body mass index (BMI)]. This study included 56 physically independent older adults (age, 68.29 ± 3.01 years; BMI, 28.09 ± 4.37 kg/m2). A multi-frequency segmental bioelectrical impedance analysis was used to measure PhA at 50 KHz. Additionally, physical function was assessed through four functional capacity tests [30-sec chair‐stand; seated medicine ball throw (SMBT); timed up & go; and 6-min walking test (6 MWT)], muscle strength through the handgrip test (dominant side) and maximal isokinetic strength of the dominant knee flexor and extensor. Moreover, bone indicators and body composition were assessed through the dual energy X-ray absorptiometry.PhA was significantly associated with SMBT (r = 0.375, effect size (ES) = moderate); 6 MWT (r = 0.396, ES = moderate); 30-sec chair‐stand (rho = 0.314, ES = moderate); knee extension (rho = 0.566, ES = large) and flexion (r = 0.459, ES = moderate); handgrip (rho = 0.432, ES = moderate); whole-body bone mineral content (BMC) (r = 0.316, ES = moderate); femoral neck BMC (r = 0.469, ES = moderate); and femoral neck bone mineral density (BMD) (rho = 0.433, ES = moderate). Additionally, the results of multiple regression analysis demonstrated that PhA is significantly associated with SMBT (p < 0.001; R2 = 0.629), 6 MWT (p = 0.004; R2 = 0.214), knee extension (p < 0.001; R2 = 0.697), knee flexion (p < 0.001; R2 = 0.355), handgrip test (p < 0.001; R2 = 0.774), whole-body BMC (p < 0.001; R2 = 0.524), femoral neck BMC (p = 0.001; R2 = 0.249), and femoral neck BMD (p = 0.020; R2 = 0.153). The results of the preliminary analysis suggested that PhA is linked to muscle strength and some factors related to physical function and bone quality in community-dwelling older adults.

Biophysical Parameters of Plasma-Derived Extracellular Vesicles as Potential Biomarkers of Bone Disturbances in Breast Cancer Patients Receiving an Individualized Nutrition Intervention.

Extracellular vesicles (EVs) are implicated in several biological conditions, including bone metabolism disturbances in breast cancer patients (BCPs). These disorders hinder the adjustment of nutrition interventions due to changes in bone mineral density (BMD). The biophysical properties of EVs (e.g., size or electrostatic repulsion) affect their cellular uptake, however, their clinical relevance is unclear. In this study, we aimed to investigate the association between the biophysical properties of the plasma-derived EVs and BMDs in BCPs who received an individualized nutrition intervention during the first six months of antineoplastic treatment. As part of the nutritional assessment before and after the intervention, body composition including bone densitometry and plasma samples were obtained. In 16 BCPs, EVs were isolated using ExoQuick® and their biophysical properties were analyzed using light-scattering techniques. We found that the average hydrodynamic diameter of large EVs was associated with femoral neck bone mineral content, lumbar spine BMD, and neoplasms' molecular subtypes. These results provide evidence that EVs play a role in BCPs' bone disorders and suggest that the biophysical properties of EVs may serve as potential nutritional biomarkers. Further studies are needed to evaluate EVs' biophysical properties as potential nutritional biomarkers in a clinical context.

Effects of exercise on bone mineral content in children and adolescents at different growth stages: a Meta-analysis

To evaluate the effect of exercise on bone mineral content(BMC) in children and adolescents at different growth stages. EMBASE, PubMed, Web of Science, CNKI, VIP database and Wanfang database were searched. The randomized controlled trials(RCTS) published in Chinese and English on the effects of exercise on BMC in children and adolescents were collected using exercise, children, adolescents and BMC as search terms. Cochrane collaboration tool was used to evaluate the quality of the included studies, and RevMan5.4 software was used for Meta-analysis. The search time limit is from the establishment of the database to July 20, 2022. A total of 18 articles(22 RCTS) involving 1305 children and adolescents were included. The result of the Meta-analysis showed that: Compared with the control group, (1) exercise significantly improved spinal BMC(SMD=0.28, 95%CI 0.17-0.40, P&lt;0.01) and femoral neck BMC(SMD=0.40, 95%CI 0.20-0.61, P&lt;0.01), but not for systemic BMC(SMD=0.08, 95%CI-0.04-0.21, P=0.19). (2) Subgroup analysis showed that exercise significantly improved spinal BMC in the following stages: prepubertal(SMD=0.48, 95%CI 0.27-0.69, P&lt;0.01)and early pubertal(SMD=0.22, 95%CI 0.05-0.39, P=0.01). The stages in which exercise significantly improved femoral neck BMC were as follows: prepubertal(SMD=0.60, 95%CI 0.05-1.16, P=0.03), early pubertal(SMD=0.22, 95%CI 0.01-0.43, P=0.04), middle and late pubertal(SMD=0.43, 95%CI 0.13-0.72, P&lt;0.01). Exercise significantly enhanced spinal BMC during preadolescence and early adolescence as well as femoral neck BMC throughout childhood and adolescence, especially with higher effect sizes during preadolescence.

Relationship between diet-related inflammation and bone health under different levels of body mass index

BackgroundOsteoporosis is a major public health problem. Dietary inflammatory preference and body mass index (BMI) are emerging factors that tends to affect bone health. There is limited evidence regarding the joint influence of BMI and dietary status on the bone health. This study aimed to investigate the relationship between dietary inflammatory index (DII) and bone health among adults under different levels of BMI utilizing the National Health and Nutrition Examination Survey (NHANES).MethodsData were collected from 2005–2010, 2013–2014 to 2017–2018 in NHANES. In total, 10,521 participants who aged ≥ 20 years and had complete data for dietary intake interview, bone mineral density (BMD) and bone mineral content (BMC) were included. DII was performed to evaluate the dietary inflammatory potential based on dietary intake interview. We evaluated bone health by femoral neck BMD and BMC measured by dual energy X-ray absorptiometry. Weighted multivariable linear regression and BMI-stratified subgroup analysis were performed.ResultsThe average DII score for 10,521 participants was 1.24 ± 0.04, mean femoral neck BMD was 0.82 ± 0.00 g/cm2 and mean BMC was 4.37 ± 0.01 g. In the fully adjusted model, there was a negative correlation between DII with BMD (β = − 0.016, P < 0.001) and BMC (β = − 0.011, P < 0.001) in the most anti-inflammatory diet. Using BMI-stratified subgroup analysis, this correlation became more evident in both the overweight (BMD: β = − 0.024, P < 0.001; BMC: β = − 0.058, P = 0.042) and obese groups (BMD: β = − 0.015, P = 0.049; BMC: β = − 0.009, P = 0.042), while this correlation was opposite in DII tertile 2 (middle DII score) in the underweight group (BMD: β = 0.047, P = 0.038; BMC: β = 0.274, P = 0.010).ConclusionRelationship between higher consumption of pro-inflammatory and increased risk of lower BMD and BMC was only existed in overweight and obese participants.

The Benefits to Bone Health in Children and Pre-School Children with Additional Exercise Interventions: A Systematic Review and Meta-Analysis.

Determine if exercise interventions, beyond what is already provided to children and preschool children, improve bone health and reduce fracture incidence. Systematic review and meta-analysis reported using the PRISMA guidelines. Certainty of evidence was assessed using GRADE recommendations. Five electronic databases were searched for records: PUBMED; CINAHL; CENTRAL; SPORTDiscus; Web of Science. Randomised, quasi-randomised and non-randomised controlled trials (including cluster-randomised) assessing the impact of additional exercise interventions (e.g., increased physical education classes or specific jumping programs) on bone health in children (6-12 years) and pre-school children (2-5 years) without dietary intervention. Thirty-one records representing 16 distinct clinical trials were included. Dual-energy X-ray Absorptiometry (DXA) and/or peripheral Quantitative Computed Tomography (pQCT) were used to quantify bone health. Increased femoral neck bone mineral content in children with additional exercise interventions (n = 790, SMD = 0.55, 95% CI = 0.01 to 1.09) was reported, however this was not significant following sensitivity analysis. Other DXA and pQCT measures, as well as fracture incidence, did not appear to significantly differ over time between intervention and control groups. No studies reported adverse events. Studies failed to report all domains within the TIDieR checklist. All studies were at high risk of bias using the Cochrane RoB Tool 2.0. The certainty of the evidence was very low. The addition of exercise interventions, beyond what is provided to children, does not appear to improve DXA and pQCT measures of bone health. The effect of additional exercise interventions on bone health in pre-school children is largely unknown. Future trials should ensure adherence is clearly reported and controlled for within analysis as well as including reports of adverse events (e.g., apophysitis) that occur due to increased exercise interventions.

The relationship between dietary intakes assessed by duplicate portion sampling method and bone health in female students: a cross-sectional study

PurposeOsteoporosis is increasingly affecting the young female adults of the Iranian population. The role of nutrition and physical activity on bone mineral content (BMC) and bone mineral density (BMD) in young female students has not been fully examined. This study aims to assess the dietary intake of several nutrients, such as calcium, phosphorus and protein; serum concentrations of vitamin D; and physical activity and their relationship with BMC and BMD in young female students.Design/methodology/approachThree-day dietary intakes of 67 female students were measured via duplicate portion sampling (DPS) method. Calcium and phosphorus content of the food samples were determined using atomic absorption spectrophotometer. Protein intake was determined by Kjeldahl method. Serum 25(OH) D concentrations were measured using enzyme-linked immunosorbent assay. Lumbar spine and femoral neck BMD were measured using dual-energy X-ray absorptiometry (DEXA).FindingsThe mean ±SD dietary intake of protein, calcium and phosphorus was 58.8 ± 16.9 g/day, 388 ± 135 mg/day and 1884 ± 682 mg/day, respectively. Significant positive correlation was found between serum vitamin 25(OH) D concentrations and BMC of lumbar spine (r = 0.28, p = 0.016) and BMD of femoral neck (r = 0.29, p = 0.016). Moreover, the authors observed a significant positive correlation between physical activity and femoral neck BMC (r = 0.26, p = 0.03) and BMD (r = 0.28, p = 0.02). This study found no significant associations between dietary intakes of protein, calcium and phosphorus and bone density measurements.Originality/valueIn this study, the authors measured the dietary intake of protein, calcium and phosphorus using DPS method. This study highlights the role of physical activity and serum vitamin 25(OH) D concentrations in female students’ bone health.

Using asynchronous quantitative computed tomography for opportunistic screening of osteoporosis

The aim – to determine the possibility of identifying individuals with osteoporosis using asynchronous computed quantitative tomography (CT) of the proximal femur by comparison with dual-energy X-ray absorptiometry (DХA).Materials and methods. The study included 40 postmenopausal women and 6 men over 50 years old (Me of age – 72.5 [65.3; 77.7] years) referred by the attending physician for densitometric examination. The patients signed an informed consent. The measurements were performed on a DXA with a narrow fan beam (Lunar Prodigy Advance, GE Healthcare, USA), and QCT on the Aquilion 64 (Canon Medical Systems, Japan). Correlation analysis and comparison of projected bone mineral density (BMD), bone mineral content (BMC), measurement area and T-score using the Blend – Altman method were carried out.Results. A statistically significant correlations were revealed between the indicators of DXA and asynchronous QCT: for femoral neck BMD r=0.93; for the T-score r=0.93; for the total hip – r=0.91 and r=0.91 respectively. When conducting the analysis using the Blend – Altman method, it was found that the QCT underestimated the value of the femoral neck BMC (bias –0.923 g), covered a smaller area of interest (bias 0.376 cm2 ), and therefore there was a shift in the values of BMD by –0.224 g/cm2 . The value of the T-score for the femoral neck had bias –0.29 standard deviations (SD), and for the total hip –0.72 SD, which were statistically significant.Conclusions. There was a high correlation between quantitative indicators of bone tissue of the proximal hip, assessed using QCT and DXA. The BMD and T-score values for the femoral neck and the total hip at QCT were lower compared to the values of the DXA results. Considering the conducted research, it is recommended that when introducing asynchronous QCT into clinical practice to identify people with osteoporosis, a synchronous phantom should be pre-scanned to compare the QCT and DXA results, followed by adjusting the BMD and T-score values for QCT by the average difference between them.

Bone mineral density in very low birthweight adults-A sibling study.

BackgroundChildren and adults born very low birthweight (VLBW, <1500 g) at preterm gestations have lower bone mineral density (BMD) and/or bone mineral content (BMC) than those born at term, but causality remains unknown.ObjectivesOur aim was to assess BMD and BMC in adults born at VLBW in a sibling comparison setting to account for shared genetic and environmental confounders.MethodsWe conducted a cohort study of 77 adults born VLBW and 70 same‐sex term‐born siblings at mean age of 29 years. The primary outcome variables were BMD Z‐scores, and BMC, of the femoral neck, lumbar spine, and whole body, measured using dual‐energy X‐ray absorptiometry. We analysed data by linear mixed models.ResultsThe VLBW adults had a 0.25 (95% CI 0.02, 0.47) Z‐score unit lower femoral neck BMD, and 0.35 (95% CI 0.16, 0.54) grams lower femoral neck BMC than their term‐born siblings, after adjustment for sex, age, and maternal smoking. Additional adjustment for adult body size attenuated the results. Lumbar spine, and whole body BMC were also lower in the VLBW group.ConclusionsIndividuals born at VLBW had lower BMC values at all three measurement sites, as well as lower femoral neck BMD Z‐scores, compared to term‐born siblings, partly explained by their smaller adult body size, but the differences were smaller than those reported previously with unrelated controls. This suggests that genetic or environmental confounders explain partly, but not exclusively, the association between preterm VLBW birth and adult bone mineralisation.

Machine Learning Identifies Stool pH as a Predictor of Bone Mineral Density in Healthy Multiethnic US Adults

BackgroundA variety of modifiable and nonmodifiable factors such as ethnicity, age, and diet have been shown to influence bone health. Previous studies are usually limited to analyses focused on the association of a few a priori variables or on a specific subset of the population. ObjectiveDietary, physiological, and lifestyle data were used to identify directly modifiable and nonmodifiable variables predictive of bone mineral content (BMC) and bone mineral density (BMD) in healthy US men and women using machine-learning models. MethodsRidge, lasso, elastic net, and random forest models were used to predict whole-body, femoral neck, and spine BMC and BMD in healthy US men and women ages 18–66 y, with a BMI (kg/m2) of 18–44 (n = 313), using nonmodifiable anthropometric, physiological, and demographic variables; directly modifiable lifestyle (physical activity, tobacco use) and dietary (via FFQ) variables; and variables approximating directly modifiable behavior (circulating 25-hydroxycholecalciferol and stool pH). ResultsMachine-learning models using nonmodifiable variables explained more variation in BMC and BMD (highest R2 = 0.75) compared with when using only directly modifiable variables (highest R2 = 0.11). Machine-learning models had better performance compared with multivariate linear regression, which had lower predictive value (highest R2 = 0.06) when using directly modifiable variables only. BMI, body fat percentage, height, and menstruation history were predictors of BMC and BMD. For directly modifiable features, betaine, cholesterol, hydroxyproline, menaquinone-4, dihydrophylloquinone, eggs, cheese, cured meat, refined grains, fruit juice, and alcohol consumption were predictors of BMC and BMD. Low stool pH, a proxy for fermentable fiber intake, was also predictive of higher BMC and BMD. ConclusionsModifiable factors, such as diet, explained less variation in the data compared with nonmodifiable factors, such as age, sex, and ethnicity, in healthy US men and women. Low stool pH predicted higher BMC and BMD. This trial was registered at http://www.clinicaltrials.gov as NCT02367287.

Physical activity induced adaptation can increase proximal femur strength under loading from a fall onto the greater trochanter.

Physical activity enhances proximal femur bone mass, but it remains unclear whether the benefits translate into an enhanced ability to resist fracture related loading. We recently used baseball pitchers as a within-subject controlled model to demonstrate physical activity induced proximal femur adaptation in regions associated with weight bearing and increased strength under single-leg stance loading. However, there was no measurable benefit to resisting common injurious loading (e.g. a fall onto the greater trochanter). A lack of power and a small physical activity effect size may have contributed to the latter null finding. Softball pitchers represent an alternative within-subject controlled model to explore adaptation of the proximal femur to physical activity, exhibiting greater dominant-to-nondominant (D-to-ND) leg differences than baseball pitchers. The current study used quantitative computed tomography, statistical parametric mapping, and subject-specific finite element (FE) modeling to explore adaptation of the proximal femur to physical activity in female softball pitchers (n=25). Female cross-country runners (n=15) were included as symmetrically loaded controls, showing very limited D-to-ND leg differences. Softball pitchers had D-to-ND leg differences in proximal femur, femoral neck, and trochanteric volumetric bone mineral density and content, and femoral neck volume. Voxel-based morphometry analyses and cortical bone mapping showed D-to-ND leg differences within a large region connecting the superior femoral head, inferior femoral neck and medial intertrochanteric region, and within the greater trochanter. FE modeling revealed pitchers had 19.4% (95%CI, 15.0 to 23.9%) and 4.9% (95%CI, 1.7 to 8.2%) D-to-ND leg differences in predicted ultimate strength under single-leg stance loading and a fall onto the greater trochanter, respectively. These data affirm the spatial and strength adaptation of the proximal femur to weight bearing directed loading and demonstrate that the changes can also have benefits, albeit smaller, on resisting loads associated with a sideways fall onto the greater trochanter.

Association between body mass index, bone bending strength, and BMD in young sedentary women.

The purpose of this study was to determine whether body mass index (BMI) is a predictor of tibial or ulnar bending strength and bone mineral density (BMD) in sedentary women. Sedentary women (n = 34), age 19-27years, with low BMI (LBMI < 18.5kg/m2, n = 16), and normal or high BMI (NHBMI between 18.5 and 29.9kg/m2, n = 18) participated as study subjects. Study outcomes included tibial and ulnar bending strength (EI in Nm2) using a non-invasive mechanical response tissue analyzer (MRTA); BMD and bone mineral content (BMC) of the whole body (WB), femoral neck (FN), total hip (TH), lumbar spine 1-4 (LS1-4), and ulna; and bone turnover biomarkers. The LBMI group have lower (p < 0.01) body weight [group difference (Δ) = 32.0%], lean mass (LM) (Δ = 23.1%), fat mass (FM) (Δ = 77.2%), and tibial bending strength (Δ = 22.0%), compared to the NHBMI. The LBMI group also have lower (all p < 0.025) BMC in WB (Δ = 19.9%), FN (Δ = 20.1%) and TH (Δ = 19.0%), compared to the NHMBI, not in BMD results. Multivariate regression analysis shows that significant predictors of tibial bending strength are tibia length (adjusted R2 = .341), age (adjusted R2 = .489), ulna BMD (adjusted R2 = .536), and LM (adjusted R2 = .580). BMI was positively correlated with tibial EI (p < 0.05), height, weight, FM, LM, body fat% (all p < 0.01), and BMD of WB, FN, TH, and LS 1-4 (p < 0.05 or < 0.01). Our results show that BMI is not a significant predictor of tibial or ulnar bending strength in young sedentary women.

The influence of snuff and smoking on bone accretion in late adolescence. The Troms\xf8 study, Fit Futures

SummaryAreal bone mineral density (aBMD) predicts future fracture risk. This study explores associations between use of tobacco and bone accretion in Norwegian adolescents. Our results indicate that use of snuff is negatively associated with accretion of aBMD in adolescence and may be a signal of increased future fracture risk.PurposeBone mineral accrual in childhood and adolescence is a long-term primary preventive strategy of osteoporosis. Areal bone mineral density (aBMD) is a surrogate measure of bone strength and a predictor of fracture risk. The aim of this population-based 2-year follow-up cohort study was to explore associations between use of snuff and smoking and changes (∆) in aBMD in Norwegian girls and boys aged 15–17 years at baseline.MethodsThe first wave of the Tromsø study, Fit Futures was conducted from 2010 to 2011. Femoral neck (FN), total hip (TH), and total body (TB) bone mineral content (BMC) and aBMD were measured by dual-energy X-ray absorptiometry. Information on use of snuff, smoking habits, and other lifestyle related variables were collected through self-administered questionnaires. Two years later, during 2012–2013, the measurements were repeated in the second wave. The present study included 349 girls and 281 boys and compared “non-users” (n = 243 girls, 184 boys) with “users” (n = 105 girls, 96 boys) of snuff and “non-smokers” (n = 327 girls, 249 boys) with “smokers” (n = 21 girls, 31 boys) using linear regression adjusted for age, baseline height and weight, change in height and weight, pubertal maturation, physical activity, ethnicity, alcohol consumption, diagnosis known to affect bone, and medication known to affect bone. The influence of “double use” on bone accretion was also explored.ResultsIn girls, no associations between use of snuff and ∆aBMD were found. In boys, use of snuff was associated with reduced bone accretion in all ∆aBMD models. Sensitivity analysis with exclusion of “sometimes” users of snuff strengthened associations at femoral sites in girls and attenuated all associations in boys. In girls, no associations between smoking and ∆aBMD were found. In boys, only the association with TB ∆aBMD was significant in the fully adjusted models. In girls, “double users” analyses showed similar association to smoking. In boys, nearly all models showed statistically significant associations with a difference of ~ 1–2% in ∆aBMD between “non-users” and “double users” during 2 years of follow-up.ConclusionsOur results indicate that tobacco use in late adolescence could be detrimental to bone accretion and may be a signal of increased fracture risk in adult life.

Feasibility and effects of 6-month home-based digitally supported E-Fit program utilizing high-intensity interval exercises in girls with adolescent idiopathic scoliosis: a randomized controlled pilot study.

Adolescent idiopathic scoliosis (AIS) patients have lower physical activities when compared with healthy controls, and are associated with lower bone mineral density (BMD), muscle strength and poorer quality of life (QoL). We aimed to assess the feasibility and effects of 6-month home-based digitally supported E-Fit comprised of high-intensity interval exercises for AIS patients. 40 AIS girls aged 11-14 were randomly assigned to E-Fit or control group. E-Fit group participated in an online 6-month home-based exercise program. At baseline, 6-months and 12-months follow-up, BMD using dual-energy X-ray absorptiometry, muscle functions, physical activity using Modified Baecke Questionnaire (MBQ), and QoL using Scoliosis Research Society-22 (SRS-22r) and feedback questionnaire were investigated. 14 in E-Fit and 16 in control group completed the study. Both groups had similar baseline characteristics. At 6-months, E-Fit group showed better improvement and significant interaction effect in left femoral neck bone mineral content (p=0.021) and isometric curl up test (p=0.04). Left arm lean mass showed better improvement between 6-months and 12-months follow-up (p=0.046) and whole-body areal BMD had significant interaction effect at 12-months follow-up (p=0.077). Improvement on self-image, work and sports participation were noted in E-Fit group across time. 70% of E-Fit participants were positive towards domestic application via online platform. E-Fit showed some benefits on bone health, muscle functions, physical activity and QoL measures. Current study indicated some potential physical and psychological benefits of E-Fit for AIS girls. E-Fit was feasible to conduct online at home and might have value of promoting exercise habits among relatively inactive AIS girls.

A Longitudinal Study of Bone Mineral Accrual during Growth in Competitive Premenarcheal Rhythmic Gymnasts

The purpose of this investigation was to study whether prolonged competitive rhythmic gymnastics training influenced bone mineral accrual in premenarcheal girls. Eighty-nine girls (45 rhythmic gymnasts [RG] and 44 untrained controls [UC]) between 7 and 9 years of age were recruited and measured annually for four years (not all participants were measured at every occasion). Dual energy x-ray absorptiometry was used to assess the development of whole body (WB), femoral neck (FN) and lumbar spine (LS) bone mineral content (BMC). In addition, body composition, blood adipokine and jumping performance characteristics were obtained. For longitudinal analyses, hierarchical mixed-effects models were constructed to predict differences in the development of WB, FN and LS BMC between RG and UC groups, while accounting for differences in body composition, blood adipokine and jumping performance values. It appeared that from 8 years of age, RG had lower (p < 0.05) fat mass and leptin values, and higher (p < 0.05) jumping performance measures in comparison with UC girls. Hierarchical mixed-effects models demonstrated that RG had 71.9 ± 12.0, 0.23 ± 0.11 and 1.39 ± 0.42 g more (p < 0.05) WB, FN and LS BMC, respectively, in comparison with UC girls. In addition, WB, FN and LS BMC increased more (p < 0.05) between 7 to 12 years of age in RG girls in comparison with UC. In conclusion, these findings suggest that the prolonged exposure to competitive rhythmic gymnastics trainings in premenarcheal girls is associated with greater bone mineral accrual despite lower body fat mass and leptin values.

Machine Learning Reveals Influence of Stool pH on Bone Mineral Density in a Healthy Multi-Ethnic U.S. Population

Abstract Objectives A variety of modifiable and non-modifiable factors such as ethnicity, age, and diet have been shown to influence bone health. Previous studies are usually limited to analyses focused on the association of a few a priori variables or on a specific subset of the population. The objective of this study was to use dietary, physiological, and lifestyle data to identify directly modifiable and non-modifiable variables predictive of bone mineral content (BMC) and bone mineral density (BMD) in healthy US men and women using machine learning models. Methods Ridge, lasso, elastic net, and random forest models were used to predict whole-body, femoral neck, and spine BMC and BMD in healthy US adults (n = 313) using non-modifiable anthropometric, physiological, and demographic variables, directly modifiable lifestyle (physical activity, tobacco use) and dietary (nutrient or food groups intake via food frequency questionnaire) variables, and variables approximating directly modifiable behavior (circulating vitamin D and stool pH). Model feature importances were used to identify variables useful for predicting BMC and BMD. Results Machine learning models using non-modifiable variables explained more variation in BMC and BMD (highest R2 = 0.750) compared to when using only directly modifiable variables (highest R2 = 0.107). Machine learning models had better performance compared to multivariate linear regression, which had lower predictive value (highest R2 = 0.063) when using directly modifiable variables only. BMI, body fat %, height, and menstruation history were predictors of BMC and BMD. For the directly modifiable features, betaine, cholesterol, hydroxyproline, menaquinone-4, dihydrophylloquinone, eggs, cheese, cured meat, refined grains, fruit juice, and alcohol consumption were predictors of BMC and BMD. Low stool pH, a proxy for fermentable fiber intake, was also predictive of higher BMC and BMD. Conclusions Machine learning models can be used to identify previously unforeseen variables that may contribute to bone health. Modifiable factors explained less variation in the data compared to other features. Low stool pH, which has been shown to be associated with fermentable fiber intake, short chain fatty acid production, and enhanced calcium absorption, was associated with higher BMC and BMD in a healthy US population. Funding Sources USDA-ARS

Insulin resistance and bone health in adolescents.

Previous studies are suggestive of the protective role of insulin on bone in adults. Whether this association exists in younger individuals is not clear, yet. This investigation aimed to evaluate the association between insulin resistance, bone parameters, and body composition amongst Iranian adolescents᾽ population. A cross-sectional study was conducted on 423 participants (224 girls and 199 boys) aged 9-19 years old. Insulin resistance was assessed, using a homeostatic model assessment of insulin resistance (HOMA-IR) and quantitative insulin sensitivity check index (QUICKI). Bone mineral density (BMD), bone mineral content (BMC), total body fat mass (TBFM), and total body lean mass (TBLM) were measured, using dual energy X-ray absorptiometry (DXA), and bone mineral apparent density (BMAD) was calculated. In multiple regression analyses adjusted for potential confounders, the HOMA-IR showed statistically significant negative association with most of the bone parameters (β = - 1.1 to - 0.002, P = 0.004 to 0.036). On the subject of QUICKI index, this relationship was detected only for lumbar spine (LS) parameters (β = 0.062 to 37.21, P = 0.0001 to 0.026) and femoral neck bone mineral content (FNBMC) (β = 1.297, P = 0.013). Our results suggest that insulin resistance may be inversely and independently associated with the bone indices in younger individuals. Whether high insulin levels have detrimental effects on growing bone is still unclear and has to be answered.