More broken bones: a 4-year double cohort study of young girls with and without distal forearm fractures

Global, regional, and national burdens of fracture in children and adolescents from 1990 to 2019

BACKGROUND

Fractures in children and adolescents(FCA) represent a significant public health concern.This underlines the essential need for comprehensive research into the global burden of disease related to FCA.

OBJECTIVE

To examine the trajectories of fracture rates and disability-adjusted life years (DALYs) in children and adolescents, as well as to identify contributing risk factors for fracture-associated DALYs between 1990 and 2019.

METHODS

This cross-sectional analysis utilized data from the Global Burden of Diseases 2019 (GBD 2019) study. It included individuals with Fracture of Childhood Age (FCA) ranging from 5 to 14 years.

RESULTS

In 2019, there were 33,646,042 incident cases of FCA were reported worldwide. South Asia exhibited the highest number of new cases (8,270,826) and DALYs (190,124 life years) in 2019, accounting for approximately one-fourth of the global data. From 1990 to 2019, the age-standardized incidence slight decreased by 21.19% and DALYs decreased by 28.99% globally. Fractures involving the radius and/r ulna (19.88%) rank as the top most prevalent FCA. Panel models analysis has pinpointed growth in adjusted national income (coefficient B 3.50, p-value 0.02) and per capita adjusted national income (coefficient B 3.48, p-value 0.03) as significant predictors of the worldwide DALYs associated with FCA.

CONCLUSION

From 1990 to 2019, the burden of FCA exhibited a notable downward trend. However, in low SDI regions such as South Asia, the burden remains substantial. It was found that national income is a risk factor for FCA-associated DALYs, highlighting the need for policies and resources directed towards FCA alongside economic development.

Association Between Vitamin D Insufficiency and Impaired Bone Density Among Adolescents With Perinatally Acquired HIV Infection

Background

Stunting and pubertal delay are common among children growing up with human immunodeficiency virus (HIV) and are associated with bone and muscle impairments. We investigated factors associated with bone density and muscle function in adolescents living with HIV (ALWH).

Methods

The VITALITY trial (PACTR202009897660297) investigated whether vitamin D and calcium supplementation improves musculoskeletal health among ALWH. A total of 842 ALWH aged 11-19 years, established on antiretroviral therapy (ART) for ≥6 months, were enrolled from HIV clinics in Zambia and Zimbabwe. Clinical history and examination were undertaken, and serum 25-hydroxyvitamin D3 (25[OH]D3) was measured. Dual-energy X-ray absorptiometry measured total-body-less-head bone mineral density adjusted for height (TBLH-BMDHT), and lumbar spine bone mineral apparent density (LS-BMAD) z scores. The association between a priori-defined covariates and musculoskeletal outcomes were investigated using baseline enrollment data and multivariable logistic regression.

Results

TBLH-BMDHT  z scores were impaired (mean, -1.42 for male and -0.63 female participants), as were LS-BMAD z scores (mean -1.15 for male and -0.47 for female participants). In bivariate analysis, early pubertal stage, less physical activity, and older age at ART initiation were associated with lower TBLH-BMDHT  z scores. Younger age, early pubertal stage, and low socioeconomic status were associated with lower LS-BMAD z scores. Grip-strength-for-height and jump-power-for-height z scores were associated with lower TBLH-BMDHT and LS-BMAD z scores. Low dietary vitamin D and calcium were associated with lower adjusted TBLH-BMDHT  z scores. Lower 25(OH)D3 was associated with lower adjusted TBLH-BMDHT and LS-BMAD z scores.

Conclusions

Deficits in bone density are common in ALWH. Vitamin D and calcium supplementation and promotion of exercise may improve musculoskeletal health among perinatally infected ALWH.

Update: Vitamin D3 and calcium carbonate supplementation for adolescents with HIV to reduce musculoskeletal morbidity and immunopathology (VITALITY trial): study protocol for a randomised placebo-controlled trial

BACKGROUND

Of the 2 million children living with HIV globally, 90% live in sub-Saharan Africa. Despite antiretroviral therapy, longstanding HIV infection is associated with several chronic complications in children including growth failure, particularly stunting and delayed puberty. Vitamin D deficiency, which is highly prevalent among children living with HIV in sub-Saharan Africa, has further adverse impact on bone health. This trial aims to establish whether supplementation with vitamin D3 and calcium carbonate improves musculoskeletal health among peripubertal children living with HIV. This paper is an update to an already existing protocol that was previously published in Trials in 2022 and details changes in the trial outcomes.

METHODS/DESIGN

We will conduct an individually randomised, double-blinded, placebo-controlled trial of weekly high-dose vitamin D3 (20,000 IU) plus daily calcium carbonate (500 mg) supplementation for 48 weeks. Eight hundred and forty children living with HIV aged 11-19 years taking ART for ≥ 6 months will be enrolled and followed up for 96 weeks. The primary outcome is DXA-measured total body less-head bone mineral density Z-score (TBLH-BMD) at 48 weeks and is an update to the previous primary outcome total body less-head bone mineral content adjusted for lean mass (TBLH-BMCLBM) Z-score. The primary outcome was updated to address the substantial differences in distributions of TBLH-BMCLBM Z-score between the two sites as a result of software differences of the DXA machines. Secondary outcomes are DXA-measured TBLH-BMD Z-score adjusted for height at 48 weeks a new secondary outcome, lumbar spine bone mineral apparent density Z-score, number of respiratory infections, lean muscle mass and grip-strength at 48 and 96 weeks, and TBLH-BMD Z-score at 96 weeks. Sub-studies will investigate the effect of the intervention on vitamin D3 pathway metabolites and markers of bone turnover, intestinal microbiota, and innate and acquired immune function.

DISCUSSION

This is the largest trial to date of vitamin D supplementation in children living with HIV. Intervening to address deficits in bone accrual through childhood is critical for optimising adolescent and early adult bone health, and prevention of later adult osteoporotic fractures. Trial results will draw attention to the need to screen for and treat long-term comorbidities in children living with HIV in resource-limited settings.

TRIAL REGISTRATION

Pan African Clinical Trials Registry PACTR20200989766029. Registered on September 3, 2020. URL of trial registry record: https://pactr.samrc.ac.za TRIAL STATUS: Participant follow-up completed; data analysis ongoing.

Analysis and validation of biomarkers of immune cell-related genes in postmenopausal osteoporosis: An observational study

Postmenopausal osteoporosis (PMOP) is a common metabolic inflammatory disease. In conditions of estrogen deficiency, chronic activation of the immune system leads to a hypo-inflammatory phenotype and alterations in its cytokine and immune cell profile, although immune cells play an important role in the pathology of osteoporosis, studies on this have been rare. Therefore, it is important to investigate the role of immune cell-related genes in PMOP. PMOP-related datasets were downloaded from the Gene Expression Omnibus database. Immune cells scores between high bone mineral density (BMD) and low BMD samples were assessed based on the single sample gene set enrichment analysis method. Subsequently, weighted gene co-expression network analysis was performed to identify modules highly associated with immune cells and obtain module genes. Differential analysis between high BMD and low BMD was also performed to obtain differentially expressed genes. Module genes are intersected with differentially expressed genes to obtain candidate genes, and functional enrichment analysis was performed. Machine learning methods were used to filter out the signature genes. The receiver operating characteristic (ROC) curves of the signature genes and the nomogram were plotted to determine whether the signature genes can be used as a molecular marker. Gene set enrichment analysis was also performed to explore the potential mechanism of the signature genes. Finally, RNA expression of signature genes was validated in blood samples from PMOP patients and normal control by real-time quantitative polymerase chain reaction. Our study of PMOP patients identified differences in immune cells (activated dendritic cell, CD56 bright natural killer cell, Central memory CD4 T cell, Effector memory CD4 T cell, Mast cell, Natural killer T cell, T follicular helper cell, Type 1 T-helper cell, and Type 17 T-helper cell) between high and low BMD patients. We obtained a total of 73 candidate genes based on modular genes and differential genes, and obtained 5 signature genes by least absolute shrinkage and selection operator and random forest model screening. ROC, principal component analysis, and t-distributed stochastic neighbor embedding down scaling analysis revealed that the 5 signature genes had good discriminatory ability between high and low BMD samples. A logistic regression model was constructed based on 5 signature genes, and both ROC and column line plots indicated that the model accuracy and applicability were good. Five signature genes were found to be associated with proteasome, mitochondria, and lysosome by gene set enrichment analysis. The real-time quantitative polymerase chain reaction results showed that the expression of the signature genes was significantly different between the 2 groups. HIST1H2AG, PYGM, NCKAP1, POMP, and LYPLA1 might play key roles in PMOP and be served as the biomarkers of PMOP.

Catgut embedding in acupoints combined with repetitive transcranial magnetic stimulation for the treatment of postmenopausal osteoporosis: study protocol for a randomized clinical trial

Background

To date, the clinical modulation for bone metabolism based on the neuro-bone mass regulation theory is still not popular. The stimulation of nerve systems to explore novel treatments for Postmenopausal osteoporosis (PMOP) is urgent and significant. Preliminary research results suggested that changes brain function and structure may play a crucial role in bone metabolism with PMOP. Thus, we set up a clinical trial to investigate the effect of the combination of repetitive transcranial magnetic stimulation (rTMS) and catgut embedding in acupoints (CEA) for PMOP and to elucidate the central mechanism of this neural stimulation in regulating bone metabolism.

Method

This trial is a prospective and randomized controlled trial. 96 PMOP participants will be randomized in a 1:1:1 ratio into a CEA group, an rTMS group, or a combined one. Participants will receive CEA, rTMS, or combined therapy for 3 months with 8 weeks of follow-up. The primary outcomes will be the changes in Bone Mineral Density scores, total efficiency of Chinese Medicine Symptoms before and after treatment. Secondary outcomes include the McGill Pain Questionnaire Short-Form, Osteoporosis Symptom Score, Mini-Mental State Examination, and Beck Depression Inventory-II. The leptin, leptin receptor, and norepinephrine levels of peripheral blood must be measured before and after treatment. Adverse events that occur during the trial will be recorded.

Discussion

CEA achieves brain-bone mass regulation through the bottom-up way of peripheral-central while rTMS achieves it through the top-down stimulation of central-peripheral. CEA combined with rTMS can stimulate the peripheral-central at the same time and promote peripheral bone mass formation. The combination of CEA and rTMS may play a coordinating, synergistic, and side-effect-reducing role, which is of great clinical significance in exploring better treatment options for PMOP.Clinical trial registration: https://www.chictr.org.cn/, identifier ChiCTR2300073863.

A practical guide to the diagnosis and management of osteoporosis in childhood and adolescence

Osteoporosis in childhood distinguishes itself from adulthood in four important ways: 1) challenges in distinguishing otherwise healthy children who have experienced fractures due to non-accidental injury or misfortunate during sports and play from those with an underlying bone fragility condition; 2) a preponderance of monogenic "early onset" osteoporotic conditions that unveil themselves during the pediatric years; 3) the unique potential, in those with residual growth and transient bone health threats, to reclaim bone density, structure, and strength without bone-targeted therapy; and 4) the need to benchmark bone health metrics to constantly evolving "normal targets", given the changes in bone size, shape, and metabolism that take place from birth through late adolescence. On this background, the pediatric osteoporosis field has evolved considerably over the last few decades, giving rise to a deeper understanding of the discrete genes implicated in childhood-onset osteoporosis, the natural history of bone fragility in the chronic illness setting and associated risk factors, effective diagnostic and monitoring pathways in different disease contexts, the importance of timely identification of candidates for osteoporosis treatment, and the benefits of early (during growth) rather than late (post-epiphyseal fusion) treatment. While there has been considerable progress, a number of unmet needs remain, the most urgent of which is to move beyond the monotherapeutic anti-resorptive landscape to the study and application of anabolic agents that are anticipated to not only improve bone mineral density but also increase long bone cross-sectional diameter (periosteal circumference). The purpose of this review is to provide a practical guide to the diagnosis and management of osteoporosis in children presenting to the clinic with fragility fractures, one that serves as a step-by-step "how to" reference for clinicians in their routine clinical journey. The article also provides a sightline to the future, emphasizing the clinical scenarios with the most urgent need for an expanded toolbox of effective osteoporosis agents in childhood.

Maternal Smoking During Pregnancy and Offspring's Risk for Bone Fracture in Childhood and Adolescence

Conditions during gestation, such as maternal smoking, may affect offspring's bone structure. This could increase the offspring's risk of bone fractures during childhood. In this study, we aimed to assess the association between prenatal exposure to maternal smoking and childhood bone fracture risk. We used a register-based birth cohort that included all children born in Finland between January 1987 and September 1990. After exclusions, the final study population consisted of 220,699 persons. Using a unique national identification number, we linked the cohort data to the fracture diagnosis in specialty care and covariate data using the Medical Birth Register (MBR), Statistics Finland and Care Register for Health Care (CRHC). The fractures were analyzed in three groups: all fractures, non-high-energy fractures, and high-energy fractures. The analyses were adjusted for sex, parity, child's year of birth, mother's age at childbirth, mother's and father's educational level, and mother's fracture status. We tested the association in three age groups: <1 year, 1-<5 years, and 5-<15 years using Cox and (recurrent fractures) Poisson regression. A total of 18,857 (8.5%) persons had at least one bone fracture diagnosis before the age of 15 years. In the age group 5-<15 years, maternal smoking during pregnancy was associated with higher fracture risk in all of the studied fracture groups: hazard ratio (HR) = 1.12 (95% confidence interval [CI] 1.06-1.17) in all fractures, 1.13 (95% CI 1.07-1.19) in non-high-energy, and 1.15 (95% CI 1.00-1.32) in high-energy fractures. There were no significant associations in other age groups in any of the fracture groups. No statistically significant association between maternal smoking during pregnancy and offspring's risk of recurrent fractures was found. In conclusion, 5- to 15-year-olds whose mothers have smoked during pregnancy have an increased risk of bone fractures treated in specialty care. © 2023 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

Differences in bone accrual over one year in young girls with obesity compared to Normal weight controls

Despite higher bone mineral density (BMD), women with obesity are at an increased risk of fracture compared to normal-weight women. Optimal adolescent bone accrual is critical for normal peak bone mass acquisition and future bone health. Whereas several studies have examined the impact of low body weight on bone accrual in youth, data are lacking regarding the impact of obesity on bone accrual. We examined bone accrual over one year in young women with moderate to severe obesity (OB) (n = 21) versus normal-weight controls (NWC) (n = 50). Participants were 13-25 years old. We used dual-energy X-ray absorptiometry to assess areal BMD (aBMD) and high resolution peripheral quantitative computed tomography (distal radius and tibia) to assess volumetric BMD (vBMD), bone geometry, and microarchitecture. Analyses were controlled for age and race. The mean age was 18.7 ± 2.7 years. OB and NWC were similar for age, race, height, and physical activity. OB had a higher BMI (p < 0.0001) and younger menarchal age (p = 0.022) than NWC. Over one year, OB did not demonstrate the increase in total hip BMD observed in NWC (p = 0.03). Increases in percent cortical area and cortical thickness, and cortical and total vBMD at the radius were lower in OB than in NWC (p ≤ 0.037). Groups did not differ for tibial bone accrual. We demonstrate that longitudinal bone accrual is impaired at the total hip and radial cortex in young women with obesity, raising concerns regarding their future bone health.

Is There an Association between BMI, Height, and Gender and Long-Bone Fractures during Childhood and Adolescence? A Large Cross-Sectional Population Study of 911,206 Subjects

INTRODUCTION

Traumatic long-bone fractures (TLFs) among children and adolescents are relatively common, with morbidity and economic consequences. Obesity has become a significant global concern. Studies have found an association between TLFs and BMI in the past but not in a large cross-sectional population study. Our study objective was to measure the incidence of TLFs in the 17-year-old general population and evaluate its association with BMI, body height, and gender.

METHODS

Data from a medical database containing all 17-year-old candidates' records before recruitment into mandatory military service were retrieved as BMI, height, gender, and history of TLFs. Logistic regression models assessed the association between BMI and height to TLFs.

RESULTS

The records of 911,206 subjects (515,339 males) were reviewed. In total, 9.65% had a history of TLFs (12.25% and 6.25% for males/females, respectively). Higher BMI was associated with TLF, with a linear trend in the odds ratio (OR) for having TLFs. The strongest association was found between obese females and TLFs (OR = 1.364, p < 0.0001). Height was an independent factor positively associated with TLFs. The OR for a TLF in the highest height quintile was 1.238 (p < 0.001) for males and 1.411 (p < 0.001) for females compared to the lowest quintile. Although TLFs were more common in males, the OR for TLFs was more prominent in females.

CONCLUSIONS

There is an association between BMI, body height, and TLFs in healthy adolescents. TLFs are more common in males, but the strongest association between overweight and obesity is evident in females.

Decreased bone mass in adolescents with bone fragility fracture but not in young children: a case-control study

Background

The incidence of distal forearm fracture due to minimal/moderate trauma shows a bimodal distribution for age at event, with one peak occurring during early adolescence, in both boys and girls and the other one in postmenopausal females. The aim of this study was, therefore, to document whether the relationship between bone mineral density and fracture is different in young children compared with adolescents.

Methods

A matched-pair, case-control study has been conducted to evaluate bone mineral density in 469 young children and 387 adolescents of both sexes, with/without fracture due to minimal/moderate trauma with assurance that the compared groups were equally susceptible to the outcome event. All fractures were radiographically confirmed. The study utilized bone mineral areal density of the total body, spine, hips, and forearm; volumetric bone mineral density of the forearm; and metacarpal radiogrammetry measurements. The study controlled for skeletal development, bone geometry, body composition, hand grip strength, calcium intake, and vitamin D status.

Results

Adolescents with distal forearm fracture have reduced bone mineral density at multiple skeletal regions of interest. This was documented by the bone mineral areal density measurements at multiple skeletal sites (p < 0.001), volumetric bone mineral density measurements of the forearm (p < 0.0001), and metacarpal radiogrammetry (p < 0.001). Adolescent females with fracture had reduced cross-sectional areas of the radius and metacarpals. The bone status of young female and male children with fracture was no different to its controls. Increased body fatness was more prevalent among fracture cases than in controls. Around 72% of young female and male children with fracture had serum 25-hydroxyvitamin D levels below the threshold of 31 ng/ml, compared with only 42% of female controls and to 51% of male controls.

Conclusions

Adolescents with bone fragility fracture had reduced bone mineral density at multiple skeletal regions of interest, whereas this was not the case with younger children. The results of the study may have implications for the prevention of bone fragility in this segment of the pediatric population.

Evaluation of overgrowth in pediatric radius fractures

PURPOSE

Forearm fractures are the most frequent long bone fractures in children. There have been many reports of differences in leg length due to overgrowth in lower extremity fractures. However, reports of such overgrowth in fractures of the upper extremity are rare. The purpose of this study was to investigate the relationship between angulation and overgrowth in pediatric radius fractures. We hypothesized that more angular deformation of the fracture would result in a periosteal transection and more overgrowth.

METHODS

Retrospectively, between 2013 and 2022, 14 patients under 16 years of age (mean age 9.43 years; 10 boys, four girls) with unilateral radius shaft or metaphyseal fracture without physeal injury, and a minimum follow-up of 12 months, were included. Demographic factors were analyzed; age, sex, body mass index (BMI), right or left. We evaluated the radiologic parameters; ulnar variances, degree of angularity before intervention, fracture gap and treatment options. The patients underwent conservative or surgical treatment.

RESULTS

The mean follow-up period was 27.9 months (range, 13-53 months). Eight patients underwent cast treatment, and six patients underwent surgical treatment. The difference in ulnar variances between the unaffected side and fracture side were statistically significant (P < 0.001). Sex, age, left or right, height, weight, and BMI were not statistically significant. The surgical treatment group (P = 0.013) and the sum of the maximum angularity (P = 0.017) were statistically significant. When the sum of the maximum angularity(SMA) was 30° or more, the ulnar variances were statistically significant, compared with the case where the SMA was less than 30°. The clinical results evaluated at the last outpatient follow-up were good in all patients.

CONCLUSIONS

First, this study implies that the degree of angulation of the fracture may affect the overgrowth of the radius in case of radius shaft or metaphyseal fracture, without physeal injury. Second, it implies that the degree of overgrowth may increase with surgical treatment, as opposed to that with conservative treatment.

LEVEL OF EVIDENCE

Level IV, Retrospective study.

Association of urinary caffeine and caffeine metabolites with bone mineral density in children and adolescents

In epidemiological research, the link between coffee consumption and bone mineral density (BMD) is still debated. Moreover, there hasn't been any research on the relationship between urine caffeine and caffeine metabolites and BMD. This study aimed to investigate if there was a connection between urine caffeine and its metabolites and BMD in people between the ages of 8 and 19. Using data from the National Health and Nutrition Examination Survey 2009 to 2014, multivariate logistic regression models were utilized to investigate the association between urinary caffeine and caffeine metabolites and total BMD. Fitted smoothing curves and generalized additive models were also used. A total of 1235 adolescents were included in this analysis, after controlling for various variables, we found that the association between urinary theophylline and total BMD was negative, whereas the association between urinary paraxanthine, theobromine and caffeine and total BMD was positive. In our study, an inverted U-shaped association between urinary paraxanthine and urinary caffeine was found with BMD in women. In this cross-sectional study, the correlation between urinary caffeine and its metabolites and total BMD differed by sex and race. More studies are needed to confirm the results of this study and to investigate the underlying causes.

Global trends and hotspots in research on osteoporosis rehabilitation: A bibliometric study and visualization analysis

Background

The field of rehabilitation medicine plays an essential role in the comprehensive management of osteoporosis and its consequences. The benefits of therapeutic exercise are increasingly being recognized in this area, which receives an increasing number of publications. this study was designed to comprehensively identify collaborative networks, parse and track research trends, spotlight present hotspots, and accurately predict frontiers and focus on the health topics related to osteoporosis rehabilitation.

Methods

This research adopted computer retrieval of osteoporosis rehabilitation-related research published in the Web of Science Core Collection (WoSCC) from inception to June 14, 2022. The bibliometric visualization and comparative analysis involving countries, institutions, journals, authors, references, and keywords were performed using the CiteSpace and VOSviewer software.

Results

A total of 3,268 articles were included, and the number of articles published each year has demonstrated a steady increase. The United States and the University of Melbourne were the highest productive country and institution, with 1,325 and 87 articles, respectively. The journal of osteoporosis international has published the greatest number of articles, with 221 publications, and the journal of bone and mineral research ranked first in the co-citation counts (cited by 11,792 times). The most productive and highly-cited authors were Heinonen A and Cummings S, with 35 publications and 680 citations.

Conclusions

At present, "physical activity," "weight bearing exercise," "muscle strength," "whole body vibration," "postmenopausal women," "older women," children, men are the noteworthy research hot topics. Future research that focus on the major modes and parameters of physical activity/exercise for osteoporosis (including whole body vibration, weight bearing exercises, resistance training), targeted multicomponent training regimens, rehabilitation therapy for postmenopausal women, older women, children and men, osteoporosis related-sarcopenia and fractures, and mesenchymal stem cells are becoming frontiers and focus on the health topics related to osteoporosis rehabilitation in the upcoming years, which are worthy of further exploration.

Is repeated childhood fracture related to areal bone density or body composition in middle age?

Childhood fracture is common, but whether it predicts adult fracture is not clear. Repeat childhood fracture was associated with adult (≤ 45 years) fracture, and in women, lower areal bone density was associated with repeat childhood fracture. Identifying fracture-prone children can modify adult fracture risk management.

INTRODUCTION

A quarter of boys and 15% of girls will suffer multiple fractures, but it is not clear whether multiple fractures during growth predict fracture risk and areal bone density in adulthood. This study evaluated whether children who repeatedly fracture were at increased risk of low areal bone density, abnormal body composition, and fractures by age 45.

METHODS

A subsample of a large birth cohort study with childhood fracture cases had areal bone density assessed at age 45 years. Participants were questioned regularly across their lifetime about fractures during childhood (ages 0-18 years of age) and adulthood (any fracture between 18 and 45 years). The number of fractures was collapsed into three categories: no fractures; 1 fracture; and > 1 fracture, separately for child and adult groups.

RESULTS

At age 45 years, areal bone mineral density (g/cm2) and body composition were measured with dual X-ray absorptiometry in n = 555 participants. Compared to no fractures, twice as many girls (14% vs 7%, P = 0.156) and boys (31.4% vs 14.1%, P = 0.004) who repeatedly fractured in childhood sustained multiple fractures as adults. Both girls and boys who were fracture-free tended to remain fracture-free as adults (79.8% compared with 62.8%, P = 0.045, and 64.8% compared with 51.4%, P = 0.025, in males and females, respectively). Participants were more than twice as likely to fracture repeatedly as adults if they had sustained multiple fractures as a child (OR 2.5 95% CI: 1.4, 4.6). Women who repeatedly fractured during childhood had lower areal bone density, whereas repeated fracturing during childhood was not associated with areal bone density or body composition in men, even after adjustment for other factors known to influence fracture history.

CONCLUSION

Childhood fracture history is associated with persistent skeletal fragility in adulthood (≤ 45 years), even after adjustment for behavioral and demographic factors known to influence fracture history.

Adiposity, Insulin Resistance, Cardiorespiratory Fitness, and Bone Health in Hispanic Children

CONTEXT

Childhood obesity disproportionately affects Hispanic youth. The skeletal system appears to be a target organ of the adverse effects of obesity. Yet, the relationship between adiposity and bone health in youth and the modulating factors are not well understood.

OBJECTIVE

This work aims to examine the relationship between adiposity, insulin resistance (IR), cardiorespiratory fitness (CRF), and bone mass in Hispanic youth.

METHODS

A total of 951 Hispanic youth (50% male), aged 4 to 19 years, participated in this cross-sectional design study from the Viva La Familia Study at Children's Nutrition Research Center. Bone mineral content (BMC) and density (BMD), lean mass (LM), total body fat mass (FM), truncal FM were obtained using dual-energy x-ray absorptiometry. Fasting glucose and insulin were obtained and the homeostasis model assessment of insulin resistance (HOMA-IR) was calculated. CRF was measured using a treadmill ramp protocol. We applied linear regression models and mediation analyses.

RESULTS

Adiposity measures were negatively related to BMC and BMD after accounting for LM and sex. IR negatively contributed whereas CRF positively contributed to the variance in BMC and BMD, more notably in the pubertal age group. In mediation analysis, HOMA-IR partially mediated the negative relationship of adiposity to BMC (standardized indirect effect [IE] = -0.0382; 95% CI, -0.0515 to -0.0264) whereas the sequential IE of HOMA-IR and CRF partially attenuated (IE = -0.0026; 95% CI, -0.0053 to -0.0005) this relationship. Similar findings were seen with BMD as the primary outcome.

CONCLUSION

IR mediates the negative relationship between adiposity and bone mass whereas CRF may partially attenuate it.

Association between total bilirubin and bone mineral density level in adolescents

Background

Increasing bone mass accumulation in adolescence and obtaining greater peak bone mass is one of the effective methods to prevent osteoporosis in the future. We aimed to examine the association between total bilirubin and bone mineral density (BMD) level in adolescents.

Methods

We used the data from 2005–2010 and 2013–2014 cycles of National Health and Nutrition Examination Survey (NHANES). The BMD levels in the region of lumbar spine and femoral regions, including total femur, femoral neck, trochanter, and intertrochanter were measured. Univariable and multivariable linear regression model were used to assess the relationship between total bilirubin concentration and BMD.

Results

A total of 3741 participants aged 12–19 years were ultimately included in the study. There were 1997 (53.38%) males and 1744 (46.62%) females. Univariate analysis results showed that age, sex, race, education, income, body mass index, dietary calcium intake, and diabetes were correlated with BMD levels. Compared with the lowest quartile of total bilirubin concentration, the highest quartile of total bilirubin concentration was positively associated with BMD levels in the regions of total femur (β = 0.036, 95% CI = 0.021 to 0.050, P < 0.001), femur neck (β = 0.030, 95% CI = 0.016 to 0.044, P < 0.001), trochanter (β = 0.033, 95% CI = 0.019 to 0.046, P < 0.001), intertrochanter (β = 0.040, 95% CI = 0.023 to 0.056, P < 0.001), and lumbar spine (β = 0.032, 95% CI = 0.018 to 0.045, P < 0.001). We also observe the same trend in sensitivity analysis (P for trend < 0.001).

Conclusion

Our study demonstrated that total bilirubin concentration was positively associated with BMD levels in adolescents in United States. Total bilirubin concentration might be a protective marker against bone loss in adolescents.

Vitamin D level, body mass index and fracture risk in children: vitamin D deficiency and fracture risk

The objective of this study was to determine the impacts of preventable causes of fracture, such as vitamin D deficiency, disturbed calcium homeostasis and obesity on fracture occurrence in minor traumas. In this way, the effects of relevant parameters on fracture may be further elucidated. A prospective case-control study in children aged 2-18 years children with and without fractures was performed. Participants with a pediatric trauma score higher than 10 presenting to minor trauma were included to exclude the significant impact of severe trauma on fracture. The effects of obesity, parameters associated with vitamin D and Ca homeostasis on fracture occurrence were evaluated. Univariate and multivariate analyses were used to test for associations between fracture status and the assessed variables. The relationships between the variables and the odds of fracture occurrence were examined using logistic regression models. The sample consisted of 76 patients and 50 controls. There were no significant differences between the patients and controls in terms of age, sex, trauma type and pubertal period. The patients had a significantly higher mean BMI percentile (61.2 ± 30.7, 36.7 ± 30.7; P < 0.001). Likewise, patients were more likely than controls to have a lower mean 25(OH)D level and mean phosphorus level (respectively, 13.4 ± 7.0, 17.3 ± 7.8; P = 0.004, and 4.6 ± 0.7, 5.1 ± 0.8; P < 0.001). Moreover, fractures were substantially more frequent in children with vitamin D deficiency (<20 ng/mL, χ2: 7.781, df: 1, P = 0.005). In the multivariate logistic model, BMI percentile and vitamin D levels remained significantly associated with increased odds of fracture [1.02 (1.01-1.04), P < 0.001 and 0.93 (0.89-0.98), P = 0.01]. The present study supports an association of high BMI and vitamin D deficiency with an increased odds of fracture occurrence in children. The findings may help physicians to reduce the risk factors of fracture by preventive efforts. Thus, unexpected health costs and morbidity may be minimized.

Vitamin D3 and calcium carbonate supplementation for adolescents with HIV to reduce musculoskeletal morbidity and immunopathology (VITALITY trial): study protocol for a randomised placebo-controlled trial

BACKGROUND

Of the 2 million children living with HIV globally, 90% live in sub-Saharan Africa. Despite antiretroviral therapy, longstanding HIV infection is associated with several chronic complications in children including growth failure, particularly stunting and delayed puberty. Vitamin D deficiency, which is highly prevalent among children living with HIV in sub-Saharan Africa, has a further adverse impact on bone health. This trial aims to establish whether supplementation with vitamin D3 and calcium carbonate improves musculoskeletal health among peripubertal children living with HIV.

METHODS/DESIGN

We will conduct an individually randomised, double-blinded, placebo-controlled trial of weekly high-dose vitamin D3 (20,000 IU) plus daily calcium carbonate (500mg) supplementation for 48 weeks. Eight hundred and forty children living with HIV aged 11-19 years taking ART for ≥6 months will be enrolled and followed up for 96 weeks. The primary outcome is total body less-head bone mineral content for lean mass adjusted for height (TBLH-BMCLBM) Z-score at 48 weeks, measured by dual-energy X-ray absorptiometry (DEXA). Secondary outcomes are DEXA-measured lumbar spine bone mineral apparent density Z-score, number of respiratory infections, lean muscle mass and grip strength at 48 and 96 weeks and TBLH-BMCLBM Z-scores at 96 weeks. Sub-studies will investigate the effect of the intervention on vitamin D3 pathway metabolites and markers of bone turnover, intestinal microbiota, and innate and acquired immune function.

DISCUSSION

This is the largest trial to date of vitamin D supplementation in children living with HIV. Intervening to address deficits in bone accrual in childhood is critical for optimising adolescent and early adult bone health and prevention of later adult osteoporotic fractures. Trial results will draw attention to the need to screen for and treat long-term comorbidities in children living with HIV in resource-limited settings.

TRIAL REGISTRATION

Pan African Clinical Trials Registry PACTR20200989766029 . Registered on 3 September 2020.

Saturation Effect of Body Mass Index on Bone Mineral Density in Adolescents of Different Ages: A Population-Based Study

BACKGROUND

Adolescence is a critical period for bone development, and peak bone mass may be reached in late adolescence. Boosting bone accumulation at this time can help preserve adult bone health and avoid osteoporosis later in life. Body mass index (BMI) has been found to have a favorable impact on bone mineral density (BMD) in previous research. However, excessive obesity is harmful to health and may lead to various systemic diseases. Therefore, finding an appropriate BMI to maintain a balance between obesity and BMD is critical for adolescents.

METHODS

The datasets from the National Health and Nutrition Examination Survey (NHANES) 2011-2020 were used in a cross-sectional investigation. Multivariate linear regression models were used to examine the linear connection between BMI and BMD. Fitted smoothing curves and threshold effect analysis were used to describe the nonlinear relationship. Subgroup analyses were then conducted based on gender and age.

RESULTS

This population-based study included a total of 6,143 adolescents aged 8-19 years. In a multivariate linear regression analysis, a good association between BMI and total BMD was shown [0.014 (0.013, 0.014)]. This positive association was maintained in all subgroup analyses grouped by sex and age. Furthermore, the association between BMI and BMD was nonlinear with a saturation point present, as evidenced by smoothed curve fitting. According to the threshold effect study, with an age group of two years, adolescents of different ages had different BMI saturation values with respect to BMD.

CONCLUSIONS

Our study showed a significant positive and saturated association between BMI and BMD in adolescents aged 8-19 years. Maintaining BMI at saturation values may reduce other adverse effects while achieving optimal BMD.

Obesity as a Predictor of Outcomes in Type III and Type IV Supracondylar Humerus Fractures

OBJECTIVES

To investigate the association of obesity with fracture characteristics and outcomes of operatively treated pediatric supracondylar humerus fractures.

DESIGN

Retrospective multicenter.

SETTING

Two Level I pediatric hospitals.

PATIENTS

Patients (age <18 years) with operatively treated Gartland type III and type IV fractures 2010-2014.

INTERVENTION

Closed or open reduction and percutaneous pinning of supracondylar humerus fractures.

MAIN OUTCOME MEASURE

Incidence of Gartland IV fracture, preoperative nerve palsy, open reduction and complication rates.

RESULTS

Patients in the obese group had a significantly higher likelihood of having a Gartland IV fracture (not obese: 17%; obese: 35%; P = 0.007). There was a significantly higher incidence of nerve palsy on presentation in the obese group (not obese: 20%; obese: 33%; P = 0.03). No significant differences were found between groups regarding incidence of open reduction, compartment syndrome, and rates of reoperation.

CONCLUSIONS

The present study demonstrates that obese children with a completely displaced supracondylar humerus fractures have an increased risk of Gartland type IV and preoperative nerve palsy compared with normal weight children.

LEVEL OF EVIDENCE

Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Effect of HIV infection on growth and bone density in peripubertal children in the era of antiretroviral therapy: a cross-sectional study in Zimbabwe

Background

Faltered linear growth and pubertal delay, which are both common in children with HIV in sub-Saharan Africa, might affect adolescent bone accrual and future fragility fracture risk. We investigated the association of HIV with bone density adjusted for skeletal size in peripubertal children in Zimbabwe.

Methods

We did a cross-sectional study of baseline data from the IMVASK cohort, which enrolled children aged 8–16 years with HIV who had been taking antiretroviral therapy (ART) for at least 2 years, and children of the same age without HIV. Children with HIV were recruited from public sector HIV clinics at Parirenyatwa General Hospital and Harare Central Hospital (Harare, Zimbabwe), and children without HIV were recruited from six schools in the same suburbs that the hospitals serve. Sociodemographic, clinical, and anthropometric data were collected. Dual-energy X-ray absorptiometry (DXA) was used to measure the bone outcomes of total-body less-head bone mineral content for lean mass adjusted for height (TBLH-BMC^LBM), and lumbar spine bone mineral apparent density (LS-BMAD), and we assessed the prevalence of low TBLH-BMC^LBM and low LS-BMAD (defined by Z-scores of less than −2·0). Size adjustment techniques were used to overcome the size dependence of DXA measurement. We used linear regression models, with multiple imputation for missing data, to assess relationships between risk factors and TBLH-BMC^LBM and LS-BMAD Z-scores in children with and without HIV.

Findings

We recruited 303 children with HIV (mean age 12·4 years [SD 2·5]; 151 [50%] girls) and 306 children without HIV (mean age 12·5 years [SD 2·5]; 155 [51%] girls). In children with HIV, median age of HIV diagnosis was 3·0 years (IQR 1·2–5·8), and median ART duration was 8·1 years (6·2–9·5); for 102 (34%) children, ART included tenofovir disoproxil fumarate (TDF). Children with HIV had a higher prevalence of low TBLH-BMC^LBM Z-score than children without HIV (29 [10%] of 279 children with available data vs 18 [6%] of 292 with available data; p=0·066) and a higher prevalence of low LS-BMAD Z-score (40 [14%] of 279 vs 17 [6%] of 293 with available data; p=0·0007). HIV and male sex were associated with earlier pubertal (Tanner) stage. The negative associations between HIV and Z-scores for TBLH-BMC^LBM and LS-BMAD were more pronounced with pubertal maturation, particularly in girls. Among children with HIV, TDF exposure and orphanhood were associated with lower TBLH-BMC^LBM Z-score in confounder-adjusted analysis. Current TDF use (vs non-TDF-based ART) was associated with a reduction in TBLH-BMC^LBM Z-score of 0·41 (95% CI 0·08–0·74; p=0·015) and in LS-BMAD Z-score of 0·31 (0·08–0·69; p=0·12).

Interpretation

Despite ART, HIV is associated with substantial skeletal deficits towards the end of puberty. The extent of bone deficits associated with TDF and its widespread use in children in sub-Saharan Africa are a concern for future adult fracture risk.

Funding

Wellcome Trust.

Non-linear association of body composition and its components with bone density in Iranian children and adolescents

Peak bone mass is established during childhood. This study aimed to evaluate the associations of the components of overall body mass with areal bone mineral density Z-score in children. The findings of this study showed that children with greater overall body mass had higher aBMD Z-score.

PURPOSE

Peak bone mass is established during childhood and adolescence. One of the important factors influencing predicted bone mass tracking in childhood and adolescence is alteration in the body composition during this growth period. This study aimed to evaluate the associations of the components of overall body mass with areal bone mineral density Z-score in children and adolescents.

METHODS

In this cross-sectional study, 478 healthy Iranian children and adolescents (237 girls and 241 boys) who had DXA measures participated. We evaluated the linearity of associations using generalized additive models.

RESULTS

Children's mean age was14 years with a range of 9-18 years, and 49.6% were girls. We found an increase in aBMD Z-score with increasing overall body mass (r = 0.25, p < 0.001). We observed this association with fat-free mass and total fat mass up to the 60th (~30 Kg) and 75th percentile (~12.5 Kg) [0.051 (95% CI, 0.027-0.075) increase in aBMD Z-score per 1 Kg increase in fat-free mass and 0.079 (95% CI, 0.044-0.114) increase in aBMD Z-score per 1 Kg increase in the total fat mass]. The correlation between Z-score of overall body mass and its components with aBMD Z-score was strongly positive. (P value < 0.001 for all) CONCLUSION: The findings of this study showed that children with greater overall body mass had higher aBMD Z-score. In addition, this study adds to a growing literature, suggesting that the relationship between body composition and BMD may be influenced by the pattern of fat and fat-free mass distribution in population.

Associations between serum calcium, 25(OH)D level and bone mineral density in adolescents

BACKGROUNDS

It is important to improve our understanding of the roles of calcium and vitamin D in bone health for preventing osteoporosis. We aimed at exploring the associations between serum calcium, vitamin D level, and bone mineral density (BMD) in adolescents included in the National Health and Nutrition Examination Survey (NHANES) 2001-2006.

METHODS

Weighted multivariate linear regression models were used to estimate the associations of serum calcium, 25(OH)D level with total BMD. Smooth curve fitting was used to explore the potential non-linear relationship.

RESULTS

A total of 5990 individuals aged between 12 and 19 years were included in this study. The fully-adjusted model showed serum calcium positively correlated with total BMD. However, an inverted U-shaped relationship was found when we performed the smooth curve fitting method, and the inflection point was calculated at 9.6 mg/dL using the two-piecewise linear regression model. In contrast, there was a positive correlation between serum 25(OH)D and total BMD after adjusting for potential confounders.

CONCLUSIONS

The present study revealed a positive correlation between serum 25(OH)D level and total BMD, and an inverted U-shaped relationship between serum calcium and total BMD.

Association between maternal smoking during pregnancy and risk of bone fractures in offspring: a systematic review and meta-analysis

This study aimed to investigate the effect of maternal smoking during pregnancy (MSDP) on the risk of bone fractures in the offspring through a systematic review and meta-analysis. The PubMed, Web of Science, and Scopus databases were systematically searched for relevant articles published through July 2019. According to heterogeneity, the pooled risk ratio (RR) and odds ratio (OR) and their corresponding 95% confidence interval (CI) were obtained using fixed or random effects models. The heterogeneity and quality of the included studies were assessed by the I-squared (I2 ) statistic and the Newcastle-Ottawa scale, respectively. Sensitivity analyses were performed to test the effect of MSDP misclassification on the results. The review of 842 search records yielded 5 studies including 8,746 mother-child pairs that were included in the meta-analysis. Pooling adjusted effect measures showed that MSDP was not associated with a later risk of bone fractures in the offspring (pooled RR, 1.15; 95% CI, 0.84-1.58; I2 =66.8%; P=0.049). After the adjustment for misclassification, MSDP may be associated with a 27% increased risk of bone fracture (pooled OR, 1.27; 95% CI, 1.00-1.62; I2 =0%; P=0.537). After the adjustment for misclassification, MSDP is associated with an increased risk of bone fractures among children whose mothers smoked during pregnancy.

The Relationship Between Prediabetes and Bone Mass in Adolescents: Analysis of the National Health and Nutrition Examination Survey From 2005 to 2010

OBJECTIVE

The purpose of this study was to observe the relationship between impaired fasting glucose (IFG), impaired glucose tolerance (IGT), and bone mineral density (BMD) in different sites in adolescents.

METHODS

A retrospective study was conducted on adolescents age 12-19 years of the United States. Data were extracted from the National Health and Nutrition Examination Survey (NHANES) 2005-2006, 2007-2008, and 2009-2010 cycles. IFG was defined as fasting plasma glucose (FPG) levels that were ≥5.6 and <7.0 mmol/L. IGT was defined as 2-h plasma glucose levels that were ≥7.8 and <11.1 mmol/L after the oral glucose tolerance test (OGTT).

RESULTS

After controlling for age, gender, race, and body mass index (BMI) Z-score, adolescents in different categories of IGT had significantly different levels of areal BMD (aBMD) and bone mineral apparent density (BMAD) (IGT main effect: P < 0.05 for all, two-way ANOVA). There was no main effect between different categories of IFG with regard to aBMD and BMAD (P > 0.05). There was no interaction between IFG and IGT with regard to aBMD and BMAD (P > 0.05). In multiple regression analysis, the 2-h plasma glucose maintained an independent association with femoral neck aBMD (β = -0.011, 95% CI: -0.017~-0.006, P < 0.001, R² = 0.012), total femur aBMD (β = -0.015, 95% CI: -0.021~-0.009, P < 0.001, R² = 0.018), total spine aBMD (β = -0.015, 95% CI: -0.020~-0.010, P < 0.001, R² = 0.018), and total spine BMAD (β = -0.002, 95% CI: -0.003~0.000, P = 0.006, R² = 0.003).

CONCLUSION

The present study demonstrates that BMD was decreased in adolescents with IGT. Two-hour plasma glucose, not FPG, negatively correlated with BMD. The effect of 2-h plasma glucose was consistent across the sites of bone.

Advances in the Bone Health Assessment of Children

The last 2 decades have seen tremendous growth in understanding the clinical characteristics of various childhood bone disorders, their mechanisms and natural histories, and their responses to treatment. In this review, the authors describe advances in bone assessment techniques for children. In addition, they provide their skeletal site-specific applications, underscore the principles that are relevant to the biology of the growing child, show how these methods assist in the diagnosis and management of pediatric bone diseases, and highlight how these techniques have shed light on bone development and underlying disease mechanisms.

Combined effects of physical activity and calcium on bone health in children and adolescents: a systematic review of randomized controlled trials

BACKGROUND

A better understanding of the role of exercise and nutrition in bone health is significant for preventing osteoporosis. The aim of this review was to assess the combined effects of physical activity and calcium intake on improving bone mineral density in children and adolescents.

METHODS

A search of electronic databases (MedLine, ISI Web of Science, Science Direct) and the literature references were performed. Randomized controlled trials published between 1997 and 2017, evaluating the effect of both physical activity and calcium intake intervention on bone mineral density or bone mineral content among children aged 3-18 years were selected. The Improved Jadad Rating Scale was used to assess the methodological quality of the included studies. Study characteristics were summarized in accordance with the review's PICO criteria. Changes in bone mineral content were detected at several different bone sites.

RESULTS

A total of nine studies involving 908 participants were included in this review. The combined intervention of physical activity and calcium increased bone mineral in children and adolescents, especially when baseline calcium intake level was low and among participants on the stage of early puberty.

CONCLUSIONS

Regular physical activity combined with high level of calcium intake is beneficial for bone health in young population. Further research is needed to evaluate the dose-response associations and long-term effects of the interaction between physical activity and calcium intake.

A single genetic locus associated with pediatric fractures: A genome-wide association study on 3,230 patients

The understanding of the biological and environmental risk factors of fractures in pediatrics is limited. Previous studies have reported that fractures involve heritable traits, but the genetic factors contributing to the risk of fractures remain elusive. Furthermore, genetic influences specific to immature bone have not been thoroughly studied. Therefore, the aim of the present study was to identify genetic variations that are associated with fractures in early childhood. The present study used a prospective Northern Finland Birth Cohort (year 1986; n=9,432). The study population was comprised of 3,230 cohort members with available genotype data. A total of 48 members of the cohort (1.5%) had in-hospital treated bone fractures during their first 6 years of life. Furthermore, individuals without fracture (n=3,182) were used as controls. A genome-wide association study (GWAS) was performed using a frequentist association test. In the GWAS analysis, a linear regression model was fitted to test for additive effects of single-nucleotide polymorphisms (SNPs; genotype dosage) adjusting for sex and performing population stratification using genotypic principal components. Using the GWAS analysis, the present study identified one locus with a significant association with fractures during childhood on chromosome 10 (rs112635931) and six loci with a suggested implication. The lead SNP rs112635931 was located near proline- and serine-rich 2 (PROSER2) antisense RNA 1 (PROSER2-AS1) and PROSER2, thus suggesting that these may be novel candidate genes associated with the risk of pediatric fractures.

Preschool Obesity Is Associated With an Increased Risk of Childhood Fracture: A Longitudinal Cohort Study of 466,997 Children and Up to 11 Years of Follow-up in Catalonia, Spain

This study aimed to determine if having an overweight or obese range body mass index (BMI) at time of beginning school is associated with increased fracture incidence in childhood. A dynamic cohort was created from children presenting for routine preschool primary care screening, collected in the Information System for Research in Primary Care (SIDIAP) platform in Catalonia, Spain. Data were collected from 296 primary care centers representing 74% of the regional pediatric population. A total of 466,997 children (48.6% female) with a validated weight and height measurement within routine health care screening at age 4 years (±6 months) between 2006 and 2013 were included, and followed up to the age of 15, migration out of region, death, or until December 31, 2016. BMI was calculated at age 4 years and classified using WHO growth tables, and fractures were identified using previously validated ICD10 codes in electronic primary care records, divided by anatomical location. Actuarial lifetables were used to calculate cumulative incidence. Cox regression was used to investigate the association of BMI category and fracture risk with adjustment for socioeconomic status, age, sex, and nationality. Median follow-up was 4.90 years (interquartile range [IQR] 2.50 to 7.61). Cumulative incidence of any fracture during childhood was 9.20% (95% confidence interval [CI] 3.79% to 14.61%) for underweight, 10.06% (9.82% to 10.29%) for normal weight, 11.28% (10.22% to 12.35%) for overweight children, and 13.05% (10.69% to 15.41%) for children with obesity. Compared with children of normal range weight, having an overweight and obese range BMI was associated with an excess risk of lower limb fracture (adjusted hazard ratio [HR] = 1.42 [1.26 to 1.59]; 1.74 [1.46 to 2.06], respectively) and upper limb fracture (adjusted HR = 1.10 [1.03 to 1.17]; 1.19 [1.07 to 1.31]). Overall, preschool children with an overweight or obese range BMI had increased incidence of upper and lower limb fractures in childhood compared with contemporaries of normal weight. © 2020 The Authors. Journal of Bone and Mineral Research published by American Society for Bone and Mineral Research.

The epidemiology of osteoporosis

INTRODUCTION

With a worldwide ageing population, the importance of the prevention and management of osteoporotic fragility fractures is increasing over time. In this review, we discuss in detail the epidemiology of fragility fractures, how this is shaped by pharmacological interventions and how novel screening programmes can reduce the clinical and economic burden of osteoporotic fractures.

SOURCES OF DATA

PubMed and Google Scholar were searched using various combinations of the keywords 'osteoporosis', 'epidemiology', 'fracture', 'screening', `FRAX' and 'SCOOP'.

AREAS OF AGREEMENT

The economic burden of osteoporosis-related fracture is significant, costing approximately $17.9 and £4 billion per annum in the USA and UK.

AREAS OF CONTROVERSY

Risk calculators such as the web-based FRAX® algorithm have enabled assessment of an individual's fracture risk using clinical risk factors, with only partial consideration of bone mineral density (BMD).

GROWING POINTS

As with all new interventions, we await the results of long-term use of osteoporosis screening algorithms and how these can be refined and incorporated into clinical practice.

AREAS TIMELY FOR DEVELOPING RESEARCH

Despite advances in osteoporosis screening, a minority of men and women at high fracture risk worldwide receive treatment. The economic and societal burden caused by osteoporosis is a clear motivation for improving the screening and management of osteoporosis worldwide.

A Contemporary View of the Definition and Diagnosis of Osteoporosis in Children and Adolescents

The last 2 decades have seen growing recognition of the need to appropriately identify and treat children with osteoporotic fractures. This focus stems from important advances in our understanding of the genetic basis of bone fragility, the natural history and predictors of fractures in chronic conditions, the use of bone-active medications in children, and the inclusion of bone health screening into clinical guidelines for high-risk populations. Given the historic focus on bone densitometry in this setting, the International Society for Clinical Densitometry published revised criteria in 2013 to define osteoporosis in the young, oriented towards prevention of overdiagnosis given the high frequency of extremity fractures during the growing years. This definition has been successful in avoiding an inappropriate diagnosis of osteoporosis in healthy children who sustain long bone fractures during play. However, its emphasis on the number of long bone fractures plus a concomitant bone mineral density (BMD) threshold ≤ -2.0, without consideration for long bone fracture characteristics (eg, skeletal site, radiographic features) or the clinical context (eg, known fracture risk in serious illnesses or physical-radiographic stigmata of osteoporosis), inappropriately misses clinically relevant bone fragility in some children. In this perspective, we propose a new approach to the definition and diagnosis of osteoporosis in children, one that balances the role of BMD in the pediatric fracture assessment with other important clinical features, including fracture characteristics, the clinical context and, where appropriate, the need to define the underlying genetic etiology as far as possible.

Impact of whole dairy matrix on musculoskeletal health and aging-current knowledge and research gaps

Dairy products are included in dietary guidelines worldwide, as milk, yoghurt, and cheese are good sources of calcium and protein, vital nutrients for bones and muscle mass maintenance. Bone growth and mineralization occur during infancy and childhood, peak bone mass being attained after early adulthood. A low peak bone mass has consequences later in life, including increased risk of osteoporosis and fractures. Currently, more than 200 million people worldwide suffer from osteoporosis, with approximately 9 million fractures yearly. This poses a tremendous economic burden on health care. Between 5% and 10% of the elderly suffer from sarcopenia, the loss of muscle mass and strength, further increasing the risk of fractures due to falls. Evidence from interventional and observational studies support that fermented dairy products in particular exert beneficial effects on bone growth and mineralization, attenuation of bone loss, and reduce fracture risk. The effect cannot be explained by single nutrients in dairy, which suggests that a combined or matrix effect may be responsible similar to the matrix effects of foods on cardiometabolic health. Recently, several plant-based beverages and products have become available and marketed as substitutes for dairy products, even though their nutrient content differs substantially from dairy. Some of these products have been fortified, in efforts to mimic the nutritional profile of milk, but it is unknown whether the additives have the same bioavailability and beneficial effect as dairy. We conclude that the dairy matrix exerts an effect on bone and muscle health that is more than the sum of its nutrients, and we suggest that whole foods, not only single nutrients, need to be assessed in future observational and intervention studies of health outcomes. Furthermore, the importance of the matrix effect on health outcomes argues in favor of making future dietary guidelines food based.

The Bones of Children With Obesity

Excess adiposity in childhood may affect bone development, ultimately leading to bone frailty. Previous reports showing an increased rate of extremity fractures in children with obesity support this fear. On the other hand, there is also evidence suggesting that bone mineral content is higher in obese children than in normal weight peers. Both adipocytes and osteoblasts derive from multipotent mesenchymal stem cells (MSCs) and obesity drives the differentiation of MSCs toward adipocytes at the expense of osteoblast differentiation. Furthermore, adipocytes in bone marrow microenvironment release a number of pro-inflammatory and immunomodulatory molecules that up-regulate formation and activation of osteoclasts, thus favoring bone frailty. On the other hand, body adiposity represents a mechanical load, which is beneficial for bone accrual. In this frame, bone quality, and structure result from the balance of inflammatory and mechanical stimuli. Diet, physical activity and the hormonal milieu at puberty play a pivotal role on this balance. In this review, we will address the question whether the bone of obese children and adolescents is unhealthy in comparison with normal-weight peers and discuss mechanisms underlying the differences in bone quality and structure. We anticipate that many biases and confounders affect the clinical studies conducted so far and preclude us from achieving robust conclusions. Sample-size, lack of adequate controls, heterogeneity of study designs are the major drawbacks of the existing reports. Due to the increased body size of children with obesity, dual energy absorptiometry might overestimate bone mineral density in these individuals. Magnetic resonance imaging, peripheral quantitative CT (pQCT) scanning and high-resolution pQCT are promising techniques for the accurate estimate of bone mineral content in obese children. Moreover, no longitudinal study on the risk of incident osteoporosis in early adulthood of children and adolescents with obesity is available. Finally, we will address emerging dietary issues (i.e., the likely benefits for the bone health of polyunsaturated fatty acids and polyphenols) since an healthy diet (i.e., the Mediterranean diet) with balanced intake of certain nutrients associated with physical activity remain the cornerstones for achieving an adequate bone accrual in young individuals regardless of their adiposity degree.

The role of PPARγ in childhood obesity-induced fractures

Globally, obesity is on the rise with ~ 30% of the world’s population now obese, and childhood obesity is following similar trends. Childhood obesity has been associated with numerous chronic conditions, including musculoskeletal disorders. This review highlights the effects of childhood adiposity on bone density by way of analyzing clinical studies and further describing two severe skeletal conditions, slipped capital femoral epiphysis and Blount’s disease. The latter half of this review discusses bone remodeling and cell types that mediate bone growth and strength, including key growth factors and transcription factors that help orchestrate this complex pathology. In particular, the transcriptional factor peroxisome proliferator-activated receptor gamma (PPARγ) is examined as it is a master regulator of adipocyte differentiation in mesenchymal stem cells (MSCs) that can also influence osteoblast populations. Obese individuals are known to have higher levels of PPARγ expression which contributes to their increased adipocyte numbers and decreased bone density. Modulating PPAR*gamma* signaling can have significant effects on adipogenesis, thereby directing MSCs down the osteoblastogenesis pathway and in turn increasing bone mineral density. Lastly, we explore the potential of PPARγ as a druggable target to decrease adiposity, increase bone density, and be a treatment for children with obesity-induced bone fractures.

Body Weight and Body Mass Index Influence Bone Mineral Density in Late Adolescence in a Two-Year Follow-Up Study. The Tromsø Study: Fit Futures

Determinants of bone acquisition in late adolescence and early adulthood are not well‐described. This 2‐year follow‐up study explored the associations of body weight (BW), body mass index (BMI), and changes in weight status with adolescent bone accretion in a sample of 651 adolescents (355 girls and 296 boys) between 15 and 19 years of age from The Tromsø Study: Fit Futures. This Norwegian population‐based cohort study was conducted from 2010 to 2011 and was repeated from 2012 to 2013. We measured femoral neck, total hip, and total body bone mineral content and areal bone mineral density (aBMD) by dual‐energy X‐ray absorptiometry. We measured height, BW, calculated BMI (kg/m ²), and collected information on lifestyle at both surveys. Mean BMI (SD) at baseline was 22.17 (3.76) and 22.18 (3.93) in girls and boys, respectively. Through multiple linear regression, baseline BW and BMI were positively associated with ∆aBMD over 2 years of follow‐up at all skeletal sites in boys ( p < 0.05), but not in girls. ∆BW and ∆BMI predicted ∆aBMD and ∆BMC in both sexes, but the strength of the associations was moderate. Individuals who lost weight during follow‐up demonstrated a slowed progression of aBMD accretion compared with those gaining weight, but loss of BW or reduction of BMI during 2 years was not associated with net loss of aBMD. In conclusion, our results confirm that adequate BW for height in late adolescence is important for bone health. Associations between change in weight status and bone accretion during follow‐up were moderate and unlikely to have any clinical implication on adolescents of normal weight. Underweight individuals, particularly boys, are at risk of not reaching optimal peak bone mass and could benefit from an increase in BMI. © 2019 The Authors. JBMR Plus is published by Wiley Periodicals, Inc. on behalf of the American Society for Bone and Mineral Research.

The Utility of DXA Assessment at the Forearm, Proximal Femur, and Lateral Distal Femur, and Vertebral Fracture Assessment in the Pediatric Population: 2019 ISCD Official Position

Dual-energy X-ray absorptiometry (DXA) is widely used in the evaluation of bone fragility in children. Previous recommendations emphasized total body less head and lumbar spine DXA scans for clinical bone health assessment. However, these scan sites may not be possible or optimal for all groups of children with conditions that threaten bone health. The utility of DXA scans of the proximal femur, forearm, and radius were evaluated for adequacy of reference data, precision, ability of predict fracture, and applicability to all, or select groups of children. In addition, the strengths and limitations of vertebral fracture assessment by DXA were evaluated. The new Pediatric Positions provide guidelines on the use of these additional measures in the assessment of skeletal health in children.

Severity of reduced bone mineral density and risk of fractures in long-term survivors of childhood leukemia and lymphoma undergoing guideline-recommended surveillance for bone health

BACKGROUND

Survivors of childhood leukemia/lymphoma are at increased risk for reduced bone mineral density (BMD). The authors sought to determine the frequency of reduced BMD detected by off-therapy surveillance, factors associated with reduced BMD, and the association of reduced BMD with fractures.

METHODS

This cross-sectional study included childhood leukemia/lymphoma survivors attending 2 survivorship clinics who received guideline-recommended BMD surveillance ≥2 years post-therapy with dual-energy x-ray absorptiometry (from January 1, 2004 to August 31, 2016). Lumbar spine BMD z-scores were height-for-age-adjusted. Low and very low BMD were >1 SD and >2 SDs below norms, respectively. Treatment, chronic conditions, and fractures were abstracted from medical records. Logistic regression was used to examine the association of low BMD with patient/treatment factors and fractures.

RESULTS

In total, 542 patients (51.5% female) with a mean age of 15.5 years (range, 4.4-52.2 years) who were 6 years post-therapy (range, 2.0-35.1 years) were evaluated, including 116 who reported post-therapy fractures. Lumbar spine low BMD was identified in 17.2% of survivors, and very low BMD was identified in 3.5% of survivors, but frequencies varied considerably between subgroups; 10.8% of survivors aged 15 to 19 years at diagnosis had very low BMD. In multivariable analyses, older age at diagnosis, white race, and being underweight were significantly associated with low BMD. Survivors with low BMD had greater odds of nondigit fractures (odds ratio, 2.2; 95% CI, 1.3-3.7) and specifically long-bone fractures (odds ratio, 2.7; 95% CI, 1.5-4.7).

CONCLUSIONS

In this study of childhood leukemia/lymphoma survivors undergoing guideline-recommended dual-energy x-ray absorptiometry surveillance, patients who were older at diagnosis, white, and underweight were at the highest risk for lumbar spine low BMD. Low BMD was associated with a greater risk of fractures, emphasizing the clinical importance of surveillance.

Older age at initiation of antiretroviral therapy predicts low bone mineral density in children with perinatally-infected HIV in Zimbabwe

BACKGROUND

Perinatally-acquired HIV infection commonly causes stunting in children; how this affects bone and muscle development is unclear. We investigated differences in bone and muscle mass and muscle function between children with HIV (CWH) and uninfected children.

SETTING

Cross-sectional study of CWH (6-16 years) receiving antiretroviral therapy (ART) for >6 months and similar aged children testing HIV-negative at primary health clinics in Zimbabwe.

METHODS

From Dual-energy X-ray Absorptiometry (DXA) we calculated total-body less-head (TBLH) Bone Mineral Content (BMC) for lean mass adjusted-for-height (TBLH-BMCLBM) Z-scores, and lumbar spine (LS) Bone Mineral Apparent Density (BMAD) Z-scores.

RESULTS

The 97 CWH were older (mean age 12.7 vs. 10.0 years) and taller (mean height 142 cm vs. 134 cm) than 77 uninfected. However, stunting (height-for-age Z-score ≤ -2) was more prevalent in CWH (35% vs. 5%, p < 0.001). Among CWH, 15% had low LS-BMAD (Z-score ≤ -2) and 13% low TBLH-BMCLBM, vs. 1% and 3% respectively in those uninfected (both p ≤ 0.02). After age, sex, height and puberty adjustment, LS-BMAD was 0.33 SDs (95%CI -0.01, 0.67; p = 0.06) lower in CWH, with no differences by HIV status in TBLH-BMCLBM, lean mass (0.11 [-0.03, 0.24], p = 0.11) or grip strength (0.05 [-0.16, 0.27], p = 0.62). However, age at ART initiation was correlated with both LS-BMAD Z-score (r = -0.33, p = 0.001) and TBLH-BMCLBM Z-score (r = -0.23, p = 0.027); for each year ART initiation was delayed a 0.13 SD reduction in LS-BMAD was seen.

CONCLUSION

Size-adjusted low bone density is common in CWH. Delay in initiating ART adversely affects bone density. Findings support immediate ART initiation at HIV diagnosis.

Risk of Recurrent Fracture: A Population-Based Study

OBJECTIVES

To determine if children who sustain a fracture in childhood had an increased rate of fracture later in childhood or early adulthood. The a priori null hypothesis was that children who sustained a fracture would not have an increased rate of future fractures compared with children who did not sustain a fracture when controlling for important covariates.

METHODS

This is a population-based retrospective cohort study using health care databases in Ontario. Approximately 2.5 million healthy children aged 0 to 15 years living in Ontario, Canada between April 1, 2003, and March 31, 2004, were included and followed for 7 years. The exposure was occurrence of any fracture during a 1-year baseline period. The main outcome was any fractures during a 7-year follow-up period.

RESULTS

A total of 43 154 children suffered a fracture during the baseline year (17.5 fractures per 1000 child years). Children with a baseline fracture had a 60% higher rate of fracture (incidence rate ratio: 1.60; 95% confidence interval: 1.46-1.75; P < .0001) during the follow-up period after adjustment for sex, rurality, history of previous fracture, and the occurrence of other injuries (head and soft-tissue).

CONCLUSIONS

The occurrence of a fracture during childhood was associated with an increased rate of future fractures compared with children who did not suffer a fracture. Attempting to improve childhood bone health by targeting children who present to a fracture clinic with multiple fracture risk factors may be a useful strategy for secondary prevention of fractures and may have beneficial effects on long-term bone health.

Obesidade, Diabetes Mellitus tipo 2 e fragilidade óssea: uma revisão narrativa

Durante anos a obesidade foi vista como um fator protetor para fraturas e osteoporose. Diversos estudos, no entanto, contestam esta tese, descrevendo que a obesidade na verdade afeta negativamente o sistema esquelético, em especial a homeostase óssea, diminuindo a rigidez do tecido ósseo e aumentando o risco de fraturas. A obesidade e o diabetes estão frequentemente associados no mesmo paciente, e a compreensão da alteração do tecido ósseo nestas duas condições clínicas é fundamental para o melhor cuidado destes pacientes, principalmente devido ao risco aumentado de fraturas, que estão associadas a maior número de complicações no seu tratamento. O presente estudo, em revisão narrativa, descreve a relação entre obesidade e homeostase óssea, a fragilidade óssea nos pacientes obesos, diabéticos ou não, e a relação entre obesidade e fraturas.

The Impact of Childhood Obesity on Skeletal Health and Development

Increased risk of fracture identified in obese children has led to a focus on the relationship between fat, bone, and the impact of obesity during skeletal development. Early studies have suggested that despite increased fracture risk, obese children have a higher bone mass. However, body size corrections applied to account for wide variations in size between children led to the finding that obese children have a lower total body and regional bone mass relative to their body size. Advances in skeletal imaging have shifted the focus from quantity of bone in obese children to evaluating the changes in bone microarchitecture that result in a change in bone quality and strength. The findings suggest that bone strength in the appendicular skeleton does not appropriately adapt to an increase in body size which results in a mismatch between bone strength and force from falls. Recent evidence points to differing influences of fat compartments on skeletal development-visceral fat may have a negative impact on bone which may be related to the associated adverse metabolic environment, while marrow adipose tissue may have an independent effect on trabecular bone development in obese children. The role of brown fat has received recent attention, demonstrating differences in the influence on bone mass between white and brown adipose tissues. Obesity results in a shift in growth and pubertal hormones as well as influences bone development through the altered release of adipokines. The change in the hormonal milieu provides an important insight into the skeletal changes observed in childhood obesity.

Bone accrual in oligo-amenorrheic athletes, eumenorrheic athletes and non-athletes

BACKGROUND

Mechanical loading improves bone mineral density (BMD) and strength while decreasing fracture risk. Cross-sectional studies show that exercise advantage is lost in oligo-amenorrheic athletes (OA). Longitudinal studies examining the opposing effects of exercise and hypogonadism on bone are lacking in adolescents/young adults.

OBJECTIVE

Evaluate differences in bone accrual over 12 months in OA, eumenorrheic athletes (EA) and non-athletes (NA). We hypothesized that bone accrual would be lower in OA than EA and NA, with differences most pronounced at non-weight bearing trabecular sites.

METHODS

27 OA, 29 EA, and 22 NA, 14-25 years old, completed 12-months of the prospective study. Athletes were weight-bearing endurance athletes. Subjects were assessed for areal BMD and bone mineral content (BMC) using DXA at the femoral neck, total hip, lumbar spine and whole body (WB). Failure load (a strength estimate) at the distal radius and tibia was assessed using microfinite element analysis of data obtained via high resolution peripheral quantitative computed tomography (HRpQCT). The primary analysis was a comparison of changes in areal BMD, BMC, and failure load across groups over 12-months at the respective sites.

RESULTS

Groups did not differ for baseline age, height or BMI. Percent body fat was lower in both OA and EA compared to NA. OA attained menarche later than EA and NA. Over the follow-up period, OA gained 1.9 ± 2.7 kg of weight compared to 0.5 ± 2.4 kg and 0.8 ± 2.3 kg in EA and NA respectively (p = 0.09); 39% of OA resumed menses. Changes in BMD, BMD Z-scores, and tibial failure load over 12-months did not differ among groups. At follow up, EA had higher femoral neck, hip and WB BMD Z-scores than NA, and higher hip BMD Z-scores than OA (p < 0.05) after adjusting for covariates. At follow-up, radial failure load was lower in OA vs. NA, and tibial failure load lower in OA and NA vs. EA (p ≤ 0.04 for all). Change in weight and fat mass were associated with changes in BMD measures at multiple sites.

CONCLUSION

Despite weight gain and menses recovery in many OA during follow-up, residual deficits persist without catch-up raising concerns for suboptimal peak bone mass acquisition.

An epidemiological evaluation of fractures and its determinants among Lebanese schoolchildren: a cross-sectional study

The purpose of this study is to establish the prevalence and determinants of fractures among 974 Lebanese schoolchildren aged 8-18. Fractures might be less common in the Lebanese pediatric population compared to western populations. Male gender and high SES are independent risk factors for fractures, while 25(OH)D and BMI have no impact.

PURPOSE

To establish the prevalence of fractures among Lebanese schoolchildren and its relationship with age, gender, BMI, 25 hydroxyvitamin D (25(OH)D) levels, and socioeconomic status (SES).

METHODS

In this cross-sectional study, 974 Lebanese schoolchildren aged 8-18 years old, mean age 13.37 ± 2.92 (508 boys and 466 girls), were recruited from 10 schools with different SES. For each participant, a questionnaire was used to collect data regarding history of fractures. Serum 25(OH)D was also measured.

RESULTS

The prevalence of Lebanese children sustaining ≥ 1 fracture was 16.9% and was higher in boys compared to girls (22.2% vs 11.1%, p < 0.0001). A 71.3% of fractures were localized in the upper limbs and 20% of participants had at least one displaced fracture. Children who sustained a fracture had a non-significant higher BMI compared to those without (p = 0.096). The percentage of children with fractures was higher in children from high SES compared to those from middle and low SES (respectively 23.3% vs. 16.3% and 13.8%, p < 0.0001). Fractures occurred at a younger age in girls compared to boys, but this difference was non-significant (p = 0.13). 25(OH)D levels were significantly higher in children with fractures compared to those without (p = 0.017). Finally, female gender was protective against upper limb fractures (p = 0.009). In a logistic regression analysis, male gender and high SES were independently associated with fractures, while BMI and 25(OH)D were not.

CONCLUSION

Our study demonstrates that the prevalence of fractures in the Lebanese pediatric population might be lower than western populations. It also confirms that male gender and high SES are independent risk factors for fractures, while 25(OH)D and BMI were not independently associated with fracture risk.

Automatic hip geometric feature extraction in DXA imaging using regional random forest

BACKGROUND

Hip fracture is considered one of the salient disability factors across the global population. People with hip fractures are prone to become permanently disabled or die from complications. Although currently the premier determiner, bone mineral density has some notable limitations in terms of hip fracture risk assessment.

OBJECTIVES

To learn more about bone strength, hip geometric features (HGFs) can be collected. However, organizing a hip fracture risk study for a large population using a manual HGFs collection technique would be too arduous to be practical. Thus, an automatic HGFs extraction technique is needed.

METHOD

This paper presents an automated HGFs extraction technique using regional random forest. Regional random forest localizes landmark points from femur DXA images using local constraints of hip anatomy. The local region constraints make random forest robust to noise and increase its performance because it processes the least number of points and patches.

RESULTS

The proposed system achieved an overall accuracy of 96.22% and 95.87% on phantom data and real human scanned data respectively.

CONCLUSION

The proposed technique's ability to measure HGFs could be useful in research on the cause and facts of hip fracture and could help in the development of new guidelines for hip fracture risk assessment in the future. The technique will reduce workload and improve the use of X-ray devices.

Mechanisms Involved in Childhood Obesity-Related Bone Fragility

Childhood obesity is one of the major health problems in western countries. The excessive accumulation of adipose tissue causes inflammation, oxidative stress, apoptosis, and mitochondrial dysfunctions. Thus, obesity leads to the development of severe co-morbidities including type 2 diabetes mellitus, liver steatosis, cardiovascular, and neurodegenerative diseases which can develop early in life. Furthermore, obese children have low bone mineral density and a greater risk of osteoporosis and fractures. The knowledge about the interplay bone tissue and between adipose is still growing, although recent findings suggest that adipose tissue activity on bone can be fat-depot specific. Obesity is associated to a low-grade inflammation that alters the expression of adiponectin, leptin, IL-6, Monocyte Chemotactic Protein 1 (MCP1), TRAIL, LIGHT/TNFSF14, OPG, and TNFα. These molecules can affect bone metabolism, thus resulting in osteoporosis. The purpose of this review was to deepen the cellular mechanisms by which obesity may facilitate osteoporosis and bone fractures.

Metacarpal Indices and Their Association with Fracture in South African Children and Adolescents

This prospective study assessed whether metacarpal indices predict fracture risk in children and adolescents. Radiogrammetry was performed at the second metacarpal midshaft on annual hand-wrist radiographs of 359 South African (SA) children aged 10-17 years. Bone length, bone width, and medullary width were measured, and the following proxies for bone strength calculated: metacarpal index (MCI), bone mineral density (BMD), section modulus (SM), stress-strain index (SSI), and slenderness index (SLI). Height and weight were measured annually. Self-reported physical activity (PA) and fracture history were obtained at ages 15 years (for the preceding 12 months) and 17 years, respectively. At 17 years, 82 (23%) participants (black, 16%; white, 42%; p < 0.001) reported a previous fracture. None of the bone measures or indices were associated with fracture in black participants. In white females, after adjusting for PA, a 1 standard deviation (SD) greater SLI doubled the fracture risk [odds ratio (OR) 2.08; 95% confidence interval (CI) 1.08, 3.98]. In white males, a 1 SD greater BMD was associated with a 2.62-fold increase in fracture risk (OR 3.62; 95% CI 1.22, 10.75), whilst a 1 SD greater SM (OR 2.29; 95% CI 1.07, 4.89) and SSI (OR 2.23; 95% CI 1.11, 4.47) were associated with a more than twofold increase in fracture risk, after height, and PA adjustment. No single index consistently predicted fracture across the four groups possibly due to ethnic and sex differences in bone geometry, muscle mass, and skeletal loading. Metacarpal radiogrammetry did not reliably predict fracture in SA children.