Bone mineral density and body composition in boys with distal forearm fractures: a dual-energy x-ray absorptiometry study

Bone health index in the assessment of bone health: The Generation R Study

Bone Health Index (BHI) has been proposed as a useful instrument for assessing bone health in children. However, its relationship with fracture risk remains unknown. We aimed to investigate whether BHI is associated with bone mineral density (BMD) and prevalent fracture odds in children from the Generation R Study. We also implemented genome-wide association study (GWAS) and polygenic score (PGS) approaches to improve our understanding of BHI and its potential. In total, 4150 children (49.4 % boys; aged 9.8 years) with genotyped data and bone assessments were included in this study. BMD was measured across the total body (less head following ISCD guidelines) using a GE-Lunar iDXA densitometer; and BHI was determined from the hand DXA scans using BoneXpert®. Fractures were self-reported collected with home questionnaires. The association of BHI with BMD and fractures was evaluated using linear models corrected for age, sex, ethnicity, height, and weight. We observed a positive correlation between BHI and BMD (ρ = 0.32, p-value<0.0001). Further, every SD decrease in BHI was associated with an 11 % increased risk of prevalent fractures (OR:1.11, 95 % CI 1.00-1.24, p-value = 0.05). Our BHI GWAS identified variants (lead SNP rs1404264-A, p-value = 2.61 × 10-14) mapping to the ING3/CPED1/WNT16 locus. Children in the extreme tails of the BMD PGS presented a difference in BHI values of -0.10 standard deviations (95% CI -0.14 to -0.07; p-value<0.0001). On top of the demonstrated epidemiological association of BHI with both BMD and fracture risk, our results reveal a partially shared biological background between BHI and BMD. These findings highlight the potential value of using BHI to screen children at risk of fracture.

Risk of wrist fracture, estimated by the load-to-strength ratio, declines following sleeve gastrectomy in adolescents and young adults

To understand whether the bone loss which occurs after vertical sleeve gastrectomy increases the risk of fracture, we used an engineering model to estimate risk in participants before and after surgery. We found that estimated risk decreased 1 year after surgery and remained lower, though had rebounded, at year 2.

PURPOSE

Vertical sleeve gastrectomy (VSG) improves metabolic health in young people with obesity but is accompanied by substantial loss of bone mass and estimated bone strength. We thus estimated fracture risk following VSG using the load-to-strength ratio (LSR), which integrates bone strength estimates with the predicted force of a fall.

METHODS

Prospective 2-year study of youth ages 13-24 years with obesity undergoing VSG (n = 24) or lifestyle therapy (n = 34). We performed high-resolution peripheral quantitative computed tomography of the distal radius and microfinite element analysis to estimate bone strength and calculated LSR.

RESULTS

VSG participants lost 26.4 ± 8.1% weight at year 1 (p < 0.001), which was sustained at year 2, while control participants gained weight at year 2 (4.5 ± 8.3%, p = 0.009). The predicted impact force decreased at years 1 and 2 following VSG (p < 0.001) but increased at year 2 among controls (p = 0.011). Estimated bone strength was unchanged at year 1 but decreased (p < 0.001) at year 2 following VSG, while bone strength did not change in controls. At year 1, the LSR decreased among VSG participants (p < 0.001), implying a lower risk of fracture. At year 2, the LSR was lower than baseline (p < 0.001), but higher compared to year 1 (p = 0.001). LSR did not change in the control group.

CONCLUSIONS

Short-term estimated fracture risk at the radius following VSG decreases. However, ongoing bone loss despite stable weight between years 1 and 2 leads to a concerning rise in estimated fracture risk. Longer follow-up will be critical to evaluate the trajectory of fracture risk. (ClinicalTrials.gov NCT02557438, registered 9/23/2015).

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.

Descriptive Epidemiology of Isolated Distal Radius Fractures in Children: Results From a Prospective Multicenter Registry

INTRODUCTION

More than 1 in 4 pediatric fractures involves the distal radius. Most prior epidemiologic studies are limited to retrospective, single center investigations, and often include adults. This study aims to describe the contemporary epidemiology of pediatric distal radius fractures using prospectively collected data from a multicenter Pediatric Distal Radius Fracture Registry.

METHODS

Patients aged 4 to 18 years diagnosed with a distal radius fracture from June 2018 through December 2019 at 4 tertiary care pediatric centers were screened and enrolled in this prospective longitudinal cohort study. Patients were excluded if they presented with bilateral distal radius fractures, polytrauma, or re-fracture. Demographic information, mechanism of injury, fracture characteristics, associated injuries, and procedural information were recorded. All radiographs were reviewed and measured. Descriptive statistics and bivariate analyses were performed.

RESULTS

A total of 1951 patients were included. The mean age was 9.9±3.3 years, and 61.3% of patients were male ( P <0.001). Most injuries occurred during a high-energy fall (33.5%) or sports participation (28.4%). The greatest proportion of fractures occurred during the spring months (38.5%). Torus fractures (44.0%) were more common than bicortical (31.3%) or physeal (21.0%) fractures. Of the physeal fractures, 84.3% were Salter-Harris type II. Associated ulnar fractures were observed in 51.2% of patients. The mean age at injury was higher for patients with physeal fractures (11.6±2.9 y) than patients with torus or bicortical fractures (9.4±3.1 and 9.6±3.1 y, respectively; P <0.001). Thirty-six percent of distal radius fractures underwent closed reduction and 3.3% underwent surgical fixation. Patients treated with closed reduction were more likely to be male (68.7% vs. 57.2%; P <0.001), obese (25.3% vs. 17.2%; P <0.001), and have bicortical fractures (62.2% vs. 14.5%; P <0.001).

CONCLUSIONS

Distal radius fractures in children have a male preponderance and are most likely to occur in the spring months and during high-energy falls and sports. Physeal fractures tend to occur in older children while torus and bicortical fractures tend to occur in younger children.

LEVEL OF EVIDENCE

Level I-prognostic.

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.

Forearm Fractures in Overweight-Obese Children and Adolescents: A Matter of Bone Density, Bone Geometry or Body Composition?

Forearm fractures in children and adolescents are associated with increased body mass index (BMI). This bone site is non-weight-bearing and therefore is appropriate to explore the effect of BMI on bone mineral density (BMD) and bone geometry, avoiding the confounding effect of increased weight-associated mechanical loading. The aim of this review was to summarize available evidence on bone indices and body composition assessed by peripheral quantitative computed tomography (pQCT) or dual X-ray absorptiometry (DXA) at the forearm level in overweight (Ow) or obese (Ob) subjects. We conducted a review of the literature according to the PICOS model. A total of 46 studies were identified following the literature search. A final number of 12 studies were included in this review. pQCT studies evidenced that Ow and Ob children typically have normal or increased volumetric BMD (vBMD), total bone area and cortical area, with normal or reduced cortical thickness at the forearm. Outcomes from DXA evaluations are less conclusive. In almost all the studies fat mass and lean mass area at the forearm are increased. A higher fat-to-lean mass ratio has been observed in few studies. Bone strength was reported as normal or increased compared to normal weight peers. In Ow or Ob children-adolescents, vBMD, bone size and bone strength are not reduced compared to normal weight peers. The local higher fat-to-lean mass ratio may give a mismatch between bone strength and the load experienced by the distal forearm during a fall, resulting in increased risk of forearm fractures.

Acquisition of peak bone mass

Peak bone mass (PBM) is a key determinant of bone mass and fragility fractures later in life. The increase in bone mass during childhood and adolescence is mainly related to an increase in bone size rather to changes in volumetric bone density. Race, gender, and genetic factors are the main determinants of PBM achievement. Nevertheless, environmental factors such as physical activity, calcium and protein intakes, weight and age at menarche, are also playing an important role in bone mass accrual during growth. Therefore, optimization of calcium and protein intakes and weight-bearing physical activity during growth is an important strategy for optimal acquisition of PBM and bone strength and for contributing to prevent fractures later in life.

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.

The effect of short-term high-caloric feeding and fasting on bone microarchitecture

BACKGROUND

States of chronic overnutrition and undernutrition are both associated with impaired bone health and increased fracture risk but there are no data on bone microarchitecture following short-term controlled nutritional challenges.

OBJECTIVE

The purpose of our study was to evaluate the impact of short-term high-caloric feeding and fasting on bone microarchitecture. We hypothesized that both high-caloric feeding and fasting would have negative effects on microarchitecture.

MATERIALS AND METHODS

We recruited 23 adult healthy subjects (13 males, 10 females, mean age 33.2 ± 1.4 years, mean BMI 26.0 ± 1.5 kg/m²). Subjects underwent an in-patient 10-day high-caloric visit (caloric intake with goal to achieve 7% weight gain), after which they went home to resume a normal diet for 13-18 days (stabilization period), and were then readmitted for a 10-day in-patient fasting stay (no caloric intake). All subjects underwent HRpQCT (XtremeCT, Scanco Medical AG, Brüttisellen, Switzerland) of the distal tibia and distal radius after each visit to assess volumetric bone mineral density (vBMD), trabecular and cortical microarchitecture, and strength estimates. The Wilcoxon signed rank test was used to perform within group comparisons.

RESULTS

During the high-caloric period, there was a mean increase in weight by 6.3 + 1.7% (p < 0.0001). There were no significant changes in bone parameters in the distal tibia or distal radius (p > 0.05). During the stabilization period there was a significant reduction in weight by -2.7 + 1.9% (p < 0.0001) but no change in bone parameters (p > 0.05). During the fasting period there was a further reduction in weight by -8.8 + 1.2% (p < 0.0001). In the distal tibia, there was a significant increase in total and cortical vBMD, trabecular and cortical parameters as well as strength estimates (p < 0.05). In the distal radius there was an increase in total and trabecular vBMD (p < 0.05), while there were no changes in other microarchitecture parameters or strengths estimates.

CONCLUSION

Short-term fasting after high-caloric feeding improves vBMD, bone microarchitecture and strength estimates of the distal tibia, while short-term high-caloric feeding does not change vBMD or microarchitecture. These results suggest that short-term fasting after high-caloric feeding in healthy individuals improves bone health and that these changes can be detected using HRpQCT in-vivo.

The impact of lifestyle on forearm fractures in children: A retrospective cohort analysis

BACKGROUND AND OBJECTIVES

Forearm fractures are frequent in children. It is important to identify predisposing factors for increased fracture risk. This retrospective analysis aimed to investigate the correlation between forearm fractures in children and co-factors such as age, TV consumption, consumption of soft drinks, the kind of soft drinks consumed as well as physical activity in daily life and BMI.

METHODS

This retrospective cohort analysis compared 355 participants at the age of 4 to 12 between 2017 and 2018 with and without forearm fractures in children. It was based on a questionnaire to assess the above-mentioned cofactors regarding behavior and lifestyles choices and aimed to identify whether or not these lead to an increased risk of forearm fractures. For statistical analysis logistic regression was used.

RESULTS

Logistic regression showed a significant effect on forearm fractures in children for the variables age (Odds ratio 3.3 [95% confidence interval 1.5-7.3], P = .003), TV consumption (Odds ratio 5.4 [95% confidence interval 2.5-22.6], P < .001), consumption of soft drinks (Odds ratio 2.6 [95% confidence interval 1.2-5.6], P = .013), and the kind of soft drinks consumed (Odds ratio 3.1 [95% confidence interval 1.5-6.3], P = .003), [Nagelkerkes-R² = 0.458; Chi² = 85.037; df = 6]) with a strong effect according to Cohen (f² = 0.84).

CONCLUSION

The study showed a significant correlation between TV and soft drink consumption and increased risk for forearm fractures in children. TV consumption and consumption of soft drinks should be reduced in children to prevent forearm fractures.

Physical Therapy to Prevent Osteopenia in Preterm Infants: A Systematic Review

Background: During the last trimester of pregnancy, about 80% of the infant’s calcium is incorporated, and for this reason, preterm infants have less bone mineralization compared to those born at term. The aim of the present systematic review was to identify, evaluate and summarize the studies that deal with the effect of physiotherapy modalities in the prevention and treatment of osteopenia in preterm infants. Methods: A comprehensive search (09/2019–02/2021) using PubMed, Web of Science, SCOPUS, ProQuest, SciELO, Latindex, ScienceDirect, PEDro and ClinicalTrials.gov was carried out. The following data were extracted: The number of participants, characteristics of the participants, design, characteristics of the intervention, outcome measures, time of evaluation and results. A non-quantitative synthesis of the extracted data was performed. The methodological quality and risk of bias were assessed using a PEDro scale and ROB-2 scale, respectively. Results: A total of 16 studies were analyzed, presenting a methodological quality that ranged from 3 to 8 points, and all showed some concerns regarding their risk of bias. Almost all studies (15/16) used passive mobilizations with joint pressure to prevent osteopenia, but they differed in the intensity and frequency of application. Conclusions: A daily exercise program of passive mobilizations with joint pressure, improves bone mineralization in preterm infants admitted to neonatal units.

The clinical features that contribute to poor bone health in young Australians living with cystic fibrosis: A recommendation for BMD screening

BACKGROUND

For Australians living with cystic fibrosis (CF), increased longevity means greater consideration needs to be given to long-term endocrine sequelae such as CF-related bone disease. Deficits in bone mass accrual are most likely to occur during childhood and adolescence. Current guidelines in Australia suggest repeat dual-energy X-ray absorptiometry (DXA) scans every 2 years. This study aims to stratify clinical factors that determine future bone health in the Australian CF population and use this to guide a more streamlined approach to bone health screening.

METHODS

This study was a retrospective audit of all patients diagnosed with CF who were treated at the Royal Children's Hospital Melbourne, Australia from 2000 to 2016 (n = 453). Two hundred and two patients had a DXA scan in the study period (191 with height-adjusted data) and 111 patients had more than one scan (108 with height-adjusted data). An investigation into the associations between bone mineral density (BMD) Z score and potential risk factors was conducted using DXA and historical data.

RESULTS

The main predictor of future BMD was the previous BMD Z score (p < .001). Other factors found to be determinants of BMD included nutritional status, lung function (FEV₁ ), age, history of previous fracture, oral corticosteroid use, and the number of hospital admissions. However, after adjusting for previous BMD, evidence of an association remained only with nutritional status, FEV₁ , and number of hospital admissions.

CONCLUSION

Second yearly scans may be unnecessary in children with an adequate DXA score on the initial scan who remain clinically stable. However, clinical deterioration in those whose BMD was previously normal, may require closer monitoring of bone health. We propose a guideline for the frequency of DXA monitoring in relation to clinical risk factors.

Deficiency of PPARγ in Bone Marrow Stromal Cells Does not Prevent High-Fat Diet-Induced Bone Deterioration in Mice

BACKGROUND

Bone marrow osteoblasts and adipocytes are derived from a common mesenchymal stem cell and have a reciprocal relationship. Peroxisome proliferator-activated receptor gamma (PPARγ), a regulator for adipocyte differentiation, may be a potential target for reducing obesity and increasing bone mass.

OBJECTIVES

This study tested the hypothesis that bone-specific Pparg conditional knockout (cKO), via deletion of Pparg from bone marrow stromal cells (BMSC) using Osterix 1 (Osx1)-Cre, would prevent high-fat (HF) diet-induced bone deterioration in mice.

METHODS

PPARγ cKO (PPARγfl/fl: Osx1-Cre) and floxed littermate control (PPARγfl/fl Osx1-Cre- ) mice that were 6 weeks old were randomly assigned to 4 groups (n = 12/group, 6 male and 6 female) and fed ad libitum with either a normal-fat (NF) purified diet (3.85 kcal/g; 10% energy as fat) or an HF diet (4.73 kcal/g; 45% energy as fat) for 6 mo. Bone structure, body composition, and serum bone-related cytokines were measured. Data were analyzed by 2-way ANOVA with Tukey post hoc comparison.

RESULTS

The HF diet decreased the tibial and lumbar vertebrae trabecular bone volume/total volume (BV/TV) by 28% and 18%, respectively, compared to the NF diet (P < 0.01). PPARγ cKO mice had 23% lower body fat mass and 9% lower lean mass than control mice. PPARγ cKO mice had 41% greater tibial trabecular BV/TV compared to control mice. None of trabecular bone parameters at the second lumbar vertebra were affected by genotype. PPARγ cKO mice had decreased cortical thickness compared to control mice. PPARγ cKO mice had a 14% lower (P < 0.01) serum concentration of leptin and a 35% higher (P < 0.05) concentration of osteocalcin compared with control mice.

CONCLUSIONS

These data indicate that PPARγ has site-specific impacts on bone structures in mice and that knockout PPARγ in BMSC increased bone mass (BV/TV) in the tibia but not the lumbar vertebrae. PPARγ disruption in BMSC did not prevent HF diet-induced bone deterioration in mice.

Serum Levels of Vitamin D in Children with or without Isolated Distal Radius Fractures: A Prospective Clinical Study

Objective  To compare the serum levels of vitamin D and minerals in children with or without isolated distal radius fractures.

Methods  The present prospective clinical study included 50 children (aged between 5 and 15 years) with isolated distal radius fractures who were admitted to our emergency unit between February and May 2018 as the study group (group A), and 50 healthy children with no history of fracture as the control group (group B). Peripheral venous blood samples were obtained and analyzed for measurements of 25-hydroxyvitamin D (25(OH)D), calcium (Ca), magnesium (Mg), phosphorus (P), alkaline phosphatase (ALP), and parathyroid hormone (PTH) in both groups. Patient characteristics and peripheral venous blood samples were compared between the groups.

Results  The mean age, height, weight, body mass index (BMI) and gender distribution were similar in both groups. There were no statistical differences in the blood analyses, including Ca, Mg, P, ALP, and PTH. However, the serum levels of 25(OH)D were statistically lower in group A when compared to group B ( p  < 0.001), and the number of patients with 25(OH)D insufficiency was statistically higher in group A than in group B (p = 0.012).

Conclusion  Children with isolated distal radius fracture should be informed about vitamin D deficiency, and, in children with low levels of vitamin D, supplementation may be considered.

Vitamin D Status of Very Low Birth Weight Neonates at Baseline and Follow-up after Daily Intake of 800 IU Vitamin D

INTRODUCTION

Vitamin D deficiency (VDD) is rampant in neonates. Recommendations for supplementation are variable.

METHODS

An observational study was done on less than 32 weeks of very low birth weight neonates to find prevalence of VDD (<20 ng/ml) at baseline; at 38 ± 2 weeks post-menstrual age (PMA) after daily intake of 800 IU vitamin D (vit D). Secondary objectives were to find determinants of VDD, to compare growth in deficient; vit D sufficient (VDS) neonates; to find vit D toxicity.

RESULTS

Of 83 neonates, 81 (97.6%) were VDD at baseline and 5 (6%) at 38 ± 2 weeks PMA. Determinants for VDD at baseline were inadequate maternal sun exposure (p < 0.001) and vit D supplementation (p = 0.007). Factors for VDD at 38 ± 2 weeks PMA were male gender (p = 0.049), morbidities (p = 0.006), ventilation >24 h (<0.001), sepsis (p = 0.032), caffeine (p ≤ 0.001) and missed supplements (p < 0.001). Weight and length gain of VDD to VDS neonates were (6.70 ± 2.40 to 8.96 ± 2.21 g/day); (0.82 ± 0.34 to 1.08 ± 0.37 cm/week), respectively (p < 0.001). Head circumference gain (cm/week) of VDS; VDD neonates was 0.58 ± 0.09; 0.54 ± 0.06 (p = 0.054), respectively. No neonates developed vit D toxicity.

CONCLUSIONS

In preterm VLBW neonates, the prevalence of VDD was 97.6% but decreased by >90% at 38 ± 2 weeks with a daily intake of 800 IU vit D. Inadequate maternal vit D intake and sun exposure determined low baseline vit D status of neonates. Male gender, morbidities, ventilation, sepsis, caffeine, missed vitamin D supplements were determinants of poor vit D status at follow-up. Weight gain and length increments were more in the VDS group.

Screening of Serum Alkaline Phosphatase and Phosphate Helps Early Detection of Metabolic Bone Disease in Extremely Low Birth Weight Infants

Background: Extremely low birth weight (ELBW, <1,000 g) infants have a high risk of metabolic bone disease (MBD). Because of the late appearance of radiological signs, diagnosis of MBD in ELBW infants might be delayed, and its prevalence underestimated in this group of patients. This study adopted serial screening of serum alkaline phosphatase (ALP) and phosphate (P) of ELBW infants to determine whether such screening is helpful for the early detection of MBD. Materials and Methods: We performed a retrospective study of preterm infants with a gestational age ≤ 31 weeks and birth weight <1,000 g. MBD was absent (ALP ≤500 IU/L), mild (ALP >500 IU/L, P ≥4.5 mg/dL), and severe (ALP >500 IU/L, P <4.5 mg/dL); MBD was divided into early MBD (≤4 weeks after birth) and late MBD (>4 weeks after birth) according to the time of onset. Results: A total of 142 ELBW infants were included, with a median gestational age of 28.1 (26.5-29.7) weeks and a median birth weight of 875 (818-950) g. Seventy-three cases of MBD were diagnosed, and the total prevalence was 51.4% (mild MBD, 10.6%; and severe MBD, 40.8%). Male sex, breastfeeding, and sepsis would increase the risk of severe MBD. Most MBD in ELBW infants occurred at 3-4 weeks after birth. Sixty-two percent (45/73) of infants were diagnosed as having early MBD, which are diagnosed earlier than late MBD [24 (21-26) vs. 39 (36-41), t = -7.161; P < 0.001]. Male sex [odds ratio (OR), 2.86; 95% confidence interval (CI), 1.07-7.64; P = 0.036], initial high ALP levels (OR, 1.02; 95% CI, 1.01-1.03; P < 0.001), and breastfeeding (OR, 5.97; 95% CI, 1.01-25.12; P = 0.049) are independent risk factors for the development of early MBD. Conclusion: The risk of MBD among ELBW infants is very high. Most cases occurred early and were severe. Male sex, initial high ALP levels, and breastfeeding are closely related to the increased risk of early MBD. Serial screening of serum ALP and P helps early detection of MBD; it is recommended to start biochemical screening for ELBW infants 2 weeks after birth and monitor their biochemical markers weekly.

Serum and Urinary Osteocalcin in Healthy 7- to 19-Year-Old Finnish Children and Adolescents

Children and adolescents have high bone turnover marker (BTM) levels due to high growth velocity and rapid bone turnover. Pediatric normative values for BTMs reflecting bone formation and resorption are vital for timely assessment of healthy bone turnover, investigating skeletal diseases, or monitoring treatment outcomes. Optimally, clinically feasible measurement protocols for BTMs would be validated and measurable in both urine and serum. We aimed to (a) establish sex- and age-specific reference intervals for urinary and serum total and carboxylated osteocalcin (OC) in 7- to 19-year-old healthy Finnish children and adolescents (n = 172), (b) validate these against standardized serum and urinary BTMs, and (c) assess the impact of anthropometry, pubertal status, and body composition on the OC values. All OC values in addition to other BTMs increased with puberty and correlated with pubertal growth, which occurred and declined earlier in girls than in boys. The mean serum total and carboxylated OC and urinary OC values and percentiles for sex-specific age categories and pubertal stages were established. Correlation between serum and urinary OC was weak, especially in younger boys, but improved with increasing age. The independent determinants for OC varied, the urinary OC being the most robust while age, height, weight, and plasma parathyroid hormone (PTH) influenced serum total and carboxylated OC values. Body composition parameters had no influence on any of the OC values. In children and adolescents, circulating and urinary OC reflect more accurately growth status than bone mineral density (BMD) or body composition. Thus, validity of OC, similar to other BTMs, as a single marker of bone turnover, remains limited. Yet, serum and urinary OC similarly to other BTMs provide a valuable supplementary tool when assessing longitudinal changes in bone health with repeat measurements, in combination with other clinically relevant parameters.

PREDICTORS OF BONE MINERAL DENSITY IN ADOLESCENTS WITH EXCESS WEIGHT

ABSTRACT Introduction: Adolescence is characterized as a phase of intense development of the skeletal system. Maximizing bone mass acquisition during adolescence may reduce the risk of bone fractures later in life. Objectives: To analyze bone mineral density (BMD) and its relation to nutritional status and serum vitamin D in adolescents with excess weight. Methods: This is a cross-sectional, exploratory study. Data from 102 adolescents with excess weight, of both sexes, were analyzed. The following indices were evaluated: body mass index (BMI), abdominal circumference (AC), intake of micronutrients (vitamin D, calcium, magnesium and phosphorus), serum 25-hydroxycholecalciferol (25(OH)D concentration, BMD of the proximal femur, lumbar spine (L1-L4) and total body, % body fat mass (% BFM), total BFM, total body lean mass (BLM), body fat mass (BFMI) and lean mass (BLMI). Results: The male adolescents (n=53) had higher values for weight, height, AC, BLM and BLMI, while the females (n=49) had higher % BFM. The majority were obese (53.9%) and had a BMD within the normal range for all evaluation sites. Of the 84 adolescents (n=84) with laboratory examination of 25OHD, 33.3% presented values considered insufficient or deficient. Multivariate linear regression analysis showed that the most important independent predictor of BMD for the girls was BLMI, regardless the evaluation site. For boys, in addition to BLMI, BMI-Z of the proximal femur (neck of the femur and total) was also was a determinant variable for BMD. Conclusion: In this sample of adolescents, BLMI was a positive predictor of BMD in both sexes; and BMI-Z was a positive predictor only in proximal femur in the boys. Level of evidence II; Prognostic studies.

Skeletal Effects of Nine Months of Physical Activity in Obese and Healthy Weight Children

PURPOSE

Obesity during adolescence has multisystem health consequences. The objective of this work was to determine whether preadolescent overweight/obese children's bones respond to a 9-month physical activity intervention by increasing bone density similar to healthy weight children.

METHODS

Participants included overweight/obese (BMI > 85%) and healthy weight (15% < BMI < 85%) preadolescents (8-9 yr old). Participants in the physical activity group participated in a 9-month physical activity curriculum every day after school. The wait list control group received no intervention. Both groups had overweight/obese children and healthy weight controls. Whole-body bone mineral content, area, and bone mineral apparent density (BMAD) were assessed using dual x-ray absorptiometry) at the beginning and end of the 9-month trial in the physical activity and control group.

RESULTS

Overweight/obese preadolescent children had higher BMAD than healthy weight children (P < 0.001 for spine, leg, and whole body). However, the density/weight (BMAD/lean mass) was lower in overweight/obese children than that in healthy weight children, indicating that the density of bones in overweight/obese children may not compensate sufficiently for the excessive load due to weight. The change in BMAD over 9 months was greater in healthy weight children than overweight/obese children in the whole body and leg, but not the lumbar spine. Physical activity caused a site-specific increase in bone density, affecting the legs more than the lumbar spine, but there was no significant difference in the effect of exercise between the healthy weight and the overweight/obese group.

CONCLUSIONS

The smaller change in BMAD over the 9 months and lower BMAD per unit lean mass in overweight/obese compared with healthy weight children may indicate a slower rate of bone mass accrual, which may have implications for bone health during skeletal growth in obese/overweight children.

Shedding "LIGHT" on the Link between Bone and Fat in Obese Children and Adolescents

Obesity may affect bone health, but literature reports are contradictory about the correlation of body mass index (BMI) and bone markers. LIGHT, one of the immunostimulatory cytokines regulating the homeostasis of bone and adipose tissue, could be involved in obesity. The study involved 111 obese subjects (12.21 ± 3.71 years) and 45 controls. Patients underwent the evaluation of bone status by quantitative ultrasonography (QUS). LIGHT amounts were evaluated in sera by ELISA, whereas its expression on peripheral blood cells was evaluated by flow cytometry. Osteoclastogenesis was performed by culturing peripheral blood mononuclear cells (PBMCs) with or without anti-LIGHT antibodies. Obese patients showed significant high BMI-standard deviation score (SDS), weight-SDS, and Homeostatic model assessment for insulin resistance (HOMA-IR) that negatively correlated with the reduced Amplitude Dependent Speed of Sound (AD-SoS)-Z-score and Bone Transmission Time (BTT-Z)-score. They displayed significantly higher serum levels of LIGHT compared with controls (497.30 ± 363.45 pg/mL vs. 186.06 ± 101.41 pg/mL, p < 0.001). LIGHT expression on monocytes, CD3+-T-cells, and neutrophils was also higher in obese patients than in the controls. Finally, in PBMC cultures, the addition of anti-LIGHT antibodies induced a significant osteoclastogenesis inhibition. Our study highlighted the high serum levels of LIGHT in obese children and adolescents, and its relationship with both the grade of obesity and bone impairment.

Bone Mineral Density of Femur and Lumbar and the Relation between Fat Mass and Lean Mass of Adolescents: Based on Korea National Health and Nutrition Examination Survey (KNHNES) from 2008 to 2011

It is most important to reach the maximum bone density in the childhood period to prevent developing osteoporosis; it is widely known that increased body weight has a positive correlation with bone density and that even though both the fat mass and lean mass have a significant impact on bone density, the latter mass has more importance for adults. Therefore, the study analyzed to identify the relationship between bone density and both fat mass and lean mass of Korean adolescents. Subjects were chosen among 21,303 people from the Korea National Health and Nutrition Examination Survey (KNHNES) between 2008 and 2011 that took a bone density checkup; as a result, 1454 teenagers aged between 12 and 18 were selected. Data analysis was performed in SAS ver. 9.4 (SAS Institute Inc., Cary, NC, USA) following the KNHNES and the weighted complex sample analysis was conducted; body fat mass and lean mass were divided into quintile groups, and to figure out the differences in bone density that were analyzed in six models adjusted by body weight (kg) and walking (yes/no), muscle strengthening exercises (yes/no), nutrition (intake of ca (g), and serum vitamin D (ng/mL)). Then, the generalized linear model (GLM) and trend test were conducted for each gender with a significance level of 0.05. The bone density differences of fat mass and lean mass were analyzed. The result of Model 6 considering all correction variables is as follows; in the case of male adolescents, the total femur and lumbar spine showed a significant difference (F = 13.120, p < 0.001; F = 12.900, p < 0.001) for fat mass, and the trend test showed that the figures significantly decreased (β = −0.030, p < 0.001; −0.035, p < 0.001). Meanwhile, for lean mass, the total femur and lumbar spine had a significant difference (F = 16.740, p < 0.001; F = 20.590, p < 0.001) too, but the trend test showed a significant increase (β = 0.054, p < 0.001; 0.057, p < 0.001). In the case of female adolescents, the lumbar spine (F = 3.600, p < 0.05) for lean mass showed a significant difference, and it also significantly rose in the trend test too (β = 0.020, p < 0.01). To sum up the results, for male adolescents, the bone density differences for fat mass (FM) and lean mass (LM) all had significant differences, but for female adolescents, only the lumbar spine for LM showed such a result. Meanwhile, both genders showed that LM had a more positive impact on bone density than FM.

Fracture risk factors among children living in New Zealand

Factures are common during childhood. There are limited data available regarding relationships between bone fracture history and calcium intake, sugar sweetened beverages (SSBs) intake, vitamin D status, physical activity (PA), ethnicity, and body composition in New Zealand (NZ) children. Identifying groups of NZ children at risk of fracture and associated predictors may help to improve bone quality during childhood and decrease the risk of fractures throughout life. The aim of this study was to investigate fracture history and associated risk factors in New Zealand children. Children aged 8-12 years were recruited. Capillary blood spots collected from a finger prick were as analyzed for 25(OH)D concentrations. Bioelectrical impedance analysis (InBody720, Seoul, Korea) was used to measure body fat percentage (%BF). Information about fracture history, siblings' history of fractures, family osteoporosis history, PA, ethnicity, and intake of calcium containing foods, and SSBs was collected using questionnaires. Children (n = 647, 354 girls), mean ± SD age 9.8 ± 0.7 years were recruited from six Auckland primary schools. NZ European (n = 252) (NZE) and South Asian (n = 68) children reported the lowest (20.2 %) and highest (44.1 %) fracture incidence, respectively. NZE compared to South Asian children, had higher 25(OH)D concentrations (74.6 ± 19.8 vs. 48.4 ± 19.3 nmol/L, P < 0.001), higher total calcium intake (764.0 ± 394.4 vs. 592.7 ± 266.3 mg/d, P < 0.018), and lower %BF (19.5 ± 6.6 vs. 23.4 ± 8.4, P < 0.003). Māori children had the next highest fracture rate (32.5 %). This group had adequate 25(OH)D (64.2 ± 18.9 nmol/L), but high %BF (23.9 %) and most participated in vigorous PA. After stratifying by sex, binary logistic regression analysis revealed the main determinants of fracture history for boys were high %BF, low 25(OH)D, low calcium intake, high SSBs consumption, siblings' fracture history, family osteoporosis history, and being South Asian; and in girls, high SSBs consumption, siblings' fracture history, and family osteoporosis history. We found South Asian ethnicity was a significant risk factor for boys. Some children were at high risk of vitamin D deficiency and for whom supplementation may be necessary in winter. Good nutrition (especially good sources of calcium and reducing SSBs intakes) should be recommended to children during growth and development to reduce their risk of fractures.

Bone outcomes following sleeve gastrectomy in adolescents and young adults with obesity versus non-surgical controls

BACKGROUND

Sleeve gastrectomy is the most commonly performed weight loss surgery in adolescents with moderate-to-severe obesity. While studies in adults have reported on the deleterious effects of gastric bypass surgery on bone structure and strength estimates, data are lacking for the impact of sleeve gastrectomy on these measures in adolescents.

OBJECTIVE

To evaluate the impact of sleeve gastrectomy on bone outcomes in adolescents and young adults over 12 months using dual energy X-ray absorptiometry (DXA) and high resolution peripheral quantitative computed tomography (HRpQCT).

PARTICIPANTS AND METHODS

We enrolled 44 youth 14-22 years old with moderate to severe obesity; 22 underwent sleeve gastrectomy and 22 were followed without surgery (16 females and 6 males in each group). At baseline and 12 months, DXA was used to assess areal bone mineral density (aBMD), HRpQCT of the distal radius and tibia was performed to assess bone geometry, microarchitecture and volumetric BMD (vBMD), and finite element analysis to assess strength estimates (stiffness and failure load). These analyses were adjusted for age, sex, race and the bone measure at baseline. Fasting blood samples were assessed for calcium, phosphorus, and 25(OH) vitamin D (25OHD) levels.

RESULTS

Over 12-months, the surgical group lost 27.2% of body weight compared to 0.1% in the non-surgical (control) group. Groups did not differ for changes in 25OHD levels (p = 0.186). Compared to controls, the surgical group had reductions in femoral neck and total hip aBMD Z-scores (p ≤ 0.0006). At the distal tibia, compared to controls, the surgical group had reductions in cortical area and thickness and trabecular number, and increases in trabecular area and separation (p ≤ 0.026). At the distal radius, the surgical group had greater reductions in trabecular vBMD, than controls (p = 0.010). The surgical group had an increase in cortical vBMD at both sites (p ≤ 0.040), possibly from a decrease in cortical porosity (p ≤ 0.024). Most, but not all, differences were attenuated after adjusting for 12-month change in BMI. Groups did not differ for changes in strength estimates over time, except that increases in tibial stiffness were lower in the surgical group (p = 0.044) after adjusting for 12-month change in BMI.

CONCLUSIONS

Over 12 months, weight loss associated with sleeve gastrectomy in adolescents had negative effects on areal BMD and certain HRpQCT parameters. However, bone strength estimates remained stable, possibly because of a simultaneous decrease in cortical porosity and increase in cortical volumetric BMD. Additional research is necessary to determine the relative contribution(s) of weight loss and the metabolic effects of surgery on bone outcomes, and whether the observed effects on bone stabilize or progress over time.

Evaluation of the effectiveness of prophylactic oral vitamin D (cholecalciferol) in children with sickle cell disease

BACKGROUND

Vitamin D (25(OH)D) deficiency has become an emerging public health problem due to its influence on skeletal and extraskeletal diseases. Bone health in patients with sickle cell disease (SCD) is especially compromised and they are more likely to have 25(OH)D deficiency than the general population. Despite this, there is little information on the efficacy of vitamin D3 (vitD3) prophylaxis and its role in improving bone mineral density (BMD) in this population.

PROCEDURES

A prospective, longitudinal, single-center study was conducted with 136 children with SCD monitored at a tertiary referral hospital for SCD. Demographic, clinical and management data, 25(OH)D levels and bone densitometries (DXA) were collected.

RESULTS

Eighty patients were included. There are significant differences between the means of each of 25(OH)D levels as a function of whether the patient started prophylactic treatment as an infant or not (35.71 vs. 27.89 ng/ml, respectively [p = .014]). In multivariate analysis, 800 IU daily dose was shown as a protective factor (p = .044) to reach optimal blood levels (≥30 ng/ml). According to Kaplan-Meier curves, patients younger than 10 years reached optimal levels earlier than older (p = .002), as well as those who were not being treated with hydroxyurea (p = .039).

CONCLUSIONS

VitD3 prophylaxis is a safe practice in SCD. It is important to start this prophylactic treatment when the child is an infant. The daily regimen with 800 IU could be more effective for reaching levels ≥30 ng/ml, and, especially in preadolescent and adolescent patients, we should raise awareness about the importance of good bone health.

Arachidonic acid status negatively associates with forearm bone outcomes and glucose homeostasis in children with an overweight condition or obesity

Long-chain polyunsaturated fatty acids are implicated in musculoskeletal health in adults. This study examined whether fatty acid status relates to bone health outcomes in children with overweight condition or obesity (body mass index z score, 3.1 ± 0.1; age, 9.0 ± 0.2 years; n = 108). Nondominant forearm bone density (distal one-third), geometry (4% site), and soft tissue composition (66%) were assessed using dual-energy X-ray absorptiometry and peripheral quantitative computed tomography. Red blood cell (RBC) fatty acid profile and indices of glucose homeostasis were measured. Differences in outcomes among RBC arachidonic acid (AA, C20:4n-6) tertiles were tested using mixed-model ANOVA. Ultra-, mid-, and total-distal forearm bone mineral content, adjusted for sex, age, percentage body fat, race, and forearm length, were 10% to 13% greater in children in the first AA tertile relative to the third. Children in the second tertile had the highest bone cross-sectional area and estimated strength at the 66% radius. Muscle cross-sectional area was 15% lower in the third tertile compared with the first, along with higher fasting insulin concentrations (27%) and homeostasis model of assessment estimate of insulin resistance (31%). Higher RBC AA status aligns with deficits in forearm bone mass, geometry, and muscle mass in children with excess adiposity and early signs of insulin resistance. Novelty Higher arachidonic acid status is associated with lower forearm bone mass in children with overweight condition or obesity. Children with higher arachidonic acid status had increased fasting insulin concentrations and indices of insulin resistance.

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.

Increasing Dietary Fish Oil Reduces Adiposity and Mitigates Bone Deterioration in Growing C57BL/6 Mice Fed a High-Fat Diet

BACKGROUND

Intake of total fat is linked to obesity and inversely associated with bone density in humans. Epidemiologic and animal studies show that long-chain n-3 (ω-3) PUFAs supplied as fish oil (FO) are beneficial to skeletal health.

OBJECTIVE

This study tested the hypothesis that increasing dietary FO would decrease adiposity and improve bone-related outcomes in growing obese mice.

METHODS

Male C57BL/6 mice at 6 wk old were assigned to 6 treatment groups and fed either a normal-fat diet (3.85 kcal/g and 10% energy as fat) or a high-fat diet (HF; 4.73 kcal/g and 45% energy as fat) containing either 0%, 3%, or 9% energy as FO (0FO, 3FO, and 9FO, respectively) ad libitum for 6 mo. Bone structure, body composition, and serum bone-related cytokines were measured.

RESULTS

The HF diet increased the expression of the adipose tissue tumor necrosis factor α (Tnfa) and serum concentrations of leptin and tartrate-resistant acid phosphatase (TRAP), and decreased serum concentrations of osteocalcin and bone-specific alkaline phosphatase (P < 0.05). FO decreased fat mass (P < 0.05), serum TRAP (P < 0.05), and adipose tissue Tnfa expression (P < 0.01). Bone content of long-chain n-3 PUFAs was increased and n-6 PUFAs were decreased with the elevation in dietary FO content (P < 0.01). Compared with mice fed 9FO, animals fed 3FO had higher femoral bone volume/total volume (25%), trabecular number (23%), connectivity density (82%), and bone mass of second lumbar vertebrae (12%) and lower femoral trabecular separation (-19%). Mice fed the 3FO HF diet had 42% higher bone mass than those fed the 0FO HF diet.

CONCLUSIONS

These data indicate increasing dietary FO ≤3% energy can decrease adiposity and mitigate HF diet-induced bone deterioration in growing C57BL/6 mice possibly by reducing inflammation and bone resorption. FO at 9% diet energy had no further beneficial effects on bone of obese mice.

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.

The Assessment of the Supply of Calcium and Vitamin D in the Diet of Women Regularly Practicing Sport

INTRODUCTION

The appropriate intake of calcium and vitamin D in women's diet is significant for a proper maintenance of the skeletal system.

RESEARCH AIM

The aim of the research was to assess the calcium and vitamin D supply in a diet among women regularly practicing sport.

METHODOLOGY

The research was completed by 593 women at the age of 18-50 (median 25) who played sports regularly (at least 2 times a week). To assess the calcium and vitamin D intake, short Food Frequency Questionnaires for calcium and vitamin D (VIDEO-FFQ) were used. The examined group was provided with the questionnaires via social media. To assess intake levels, the authors applied the group-based cutoff point method (calcium norm was EAR 800 mg/day; vitamin D norm was AI 15 μg/day).

RESULTS

The median of calcium and vitamin D intake in a diet was 502 mg/day and 5.2 μg/day, respectively (Q25 and Q75 for calcium was 387 mg/day and 627 mg/day, respectively, and for vitamin D was 3.4 μg/day and 8.2 μg/day, respectively). In relation to the EAR norm for calcium and AI norm for vitamin D, 92.0% of the examined participants in a group demonstrated lower than recommended calcium intake levels and 97.3% showed lower than recommended vitamin D intake levels. Calcium and vitamin D supplementation was used by 13.1% (in this subgroup, 11.5% of the examined group members did not need it) and 56.8% of the examined women (in this subgroup, 2.4% of the examined group did not need it), respectively. After including the calcium and vitamin D intake, the supply median for the whole group was 535 mg/day and 28.8 μg/day, respectively (Q25 and Q75 for calcium was 402 mg/day and 671 mg/day, and for vitamin D was 6.3 µg/day and 55.7 μg/day, respectively); 87.5% of the examined participants did not meet the EAR norms for calcium and 42.0% did not meet the AI norm for vitamin D. Among the women supplementing calcium, 58.9% did not reach the reference intake value; however, all women supplementing vitamin D fulfilled the expected nutritional need.

CONCLUSIONS

It is important to educate women about the necessity to provide the body with proper calcium and vitamin D intake levels in a diet in order to avoid health problems resulting from the deficit of the nutrients.

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.

Early Acid Suppression Therapy Exposure and Fracture in Young Children

BACKGROUND

Acid suppression therapy (AST), including proton pump inhibitors (PPIs) and histamine H₂-receptor antagonists (H₂RAs), is frequently prescribed to treat symptomatic gastroesophageal reflux in otherwise healthy infants. PPI use has been associated with increased fracture risk in older adults; 2 preliminary studies in children have conflicting results.

METHODS

A retrospective cohort of children born 2001 to 2013 who were followed for ≥2 years was formed. Those with osteogenesis imperfecta, cholestasis, or child maltreatment were excluded. Prescription data were used to identify AST prescription before age 1 year. International Classification of Diseases, Ninth Revision, Clinical Modification codes identified fractures after age 1 year. A Cox proportional hazard analysis assessed fracture hazard and was adjusted for sex, prematurity, low birth weight, previous fracture, anti-epileptics, and overweight or obesity.

RESULTS

Of 851 631 included children, 97 286 (11%) were prescribed AST in the first year of life; 7998 (0.9%) children were prescribed PPI, 71 578 (8%) were prescribed H₂RA, and 17 710 (2%) were prescribed both a PPI and H₂RA. Infants prescribed AST had an earlier median first fracture age (3.9 vs 4.5 years). After adjustment, increased fracture hazard was associated with PPI use (21%) and PPI and H₂RA use (30%), but not H₂RA use alone. Longer duration of AST treatment and earlier age of first AST use was associated with increased fracture hazard.

CONCLUSIONS

Infant PPI use alone and together with H₂RAs is associated with an increased childhood fracture hazard, which appears amplified by days of use and earlier initiation of ASTs. Use of AST in infants should be weighed carefully against possible fracture.

Suboptimal bone microarchitecure in adolescent girls with obesity compared to normal-weight controls and girls with anorexia nervosa

BACKGROUND

Despite their higher areal bone mineral density (aBMD), adolescents with obesity (OB) have an increase in fracture risk, particularly of the extremities, compared with normal-weight controls. Whereas bone parameters that increase fracture risk are well characterized in anorexia nervosa (AN), the other end of nutritional spectrum, these data are lacking in adolescents with obesity.

OBJECTIVE

Our objective was to compare bone parameters in adolescent girls across the nutritional spectrum, to determine whether suboptimal bone adaptation to increased body weight may explain the increased fracture risk in OB.

METHODS

We assessed bone endpoints in 153 adolescent girls 14-21 years old: 50 OB, 48 controls and 55 AN. We used (i) DXA to assess aBMD at the lumbar spine, proximal femur and whole body, and body composition, (ii) high resolution peripheral quantitative CT (HRpQCT) to assess bone geometry, microarchitecture and volumetric BMD (vBMD), and (iii) finite element analysis to assess failure load (a strength estimate) at the distal radius and tibia. All aBMD, microarchitecture and FEA analyses were controlled for age and race.

RESULTS

Groups did not differ for age or height. Areal BMD Z-scores at all sites were highest in OB, intermediate in controls and lowest in AN (p < 0.0001). At the radius, cortical area and thickness were higher in OB compared to AN and control groups (p = 0.001) while trabecular area did not differ across groups. Compared to controls, OB had higher cortical porosity (p = 0.003), higher trabecular thickness (p = 0.024), and higher total, cortical and trabecular vBMD and rod BV/TV (p < 0.04). Plate BV/TV did not differ in OB vs. controls, but was higher than in AN (p = 0.001). At the tibia, total, cortical, and trabecular area and cortical thickness were higher in OB vs. controls and AN (p < 0.005). OB also had higher cortical porosity (p < 0.007) and lower trabecular thickness (p < 0.02) than the other two groups. Trabecular number, total and trabecular vBMD, and rod BV/TV were higher in OB vs. controls and AN (p < 0.02), while cortical vBMD and plate BV/TV did not differ in OB vs. the other two groups. Finally, failure load (a strength estimate) was higher in OB at the radius and tibia compared to controls and AN (p < 0.004 for all). However, after adjusting for body weight, failure load was lower in OB vs. controls at both sites (p < 0.05), and lower than in AN at the distal tibia.

CONCLUSION

Not all bone parameters demonstrate appropriate adaptation to higher body weight. Cortical porosity and plate BV/TV at the radius and tibia, and cortical vBMD and trabecular thickness at the tibia are particularly at risk. These effects may contribute to the higher risk for fracture reported in OB vs. controls.

Recovery of Bone Mineral Mass After Upper Limb Fractures in Children and Teenagers

BACKGROUND

Loss of bone mineral mass and muscle atrophy are predictable consequences of cast-mediated immobilization following wrist and forearm fractures. This study aimed to prospectively determine whether previously reported lower bone mineral mass following immobilization for wrist and forearm fractures in children and teenagers had recovered at 6- and 18-month follow-up.

METHODS

We recruited 50 children and teenagers who underwent a cast-mediated immobilization for a forearm or wrist fracture. Dual-energy x-ray absorptiometry scans of different skeletal sites were performed at the time of fracture, at cast removal, at 6 and at 18-month follow-up. Injured patients were paired with healthy controls according to sex and age. Dual-energy x-ray absorptiometry values were compared between groups and the injured and uninjured forearms of the patients.

RESULTS

At the time of fracture, injured and healthy subjects showed no differences between their bone mineral density (BMD) and bone mineral content (BMC) z-scores at the lumbar spine, or between their BMDs at the peripheral wrist. At cast removal, upper limb bone mineral variables were significantly lower in the injured group (except for the ultradistal radius) than in the uninjured group, with differences ranging from 3.8% to 10.2%. No residual decrease in bone mineral variables was observed at any upper limb site at 6- and 18-month follow-up (28 injured patients). Significant residual increases in the BMDs and BMCs were observed for the injured group's ultradistal radius and whole wrists (+4.8% to +5.2%).

CONCLUSIONS

A rapid bone mass reversal occurs by resumption of mobilization, with full bone recovery 6 months after a forearm or wrist fracture. Finally, healing bone callus could introduce a bias into the interpretation of BMD and BMC data at the fracture site, not only at cast removal but also 18 months after the fracture.

Physical Performance Variables and Bone Parameters in a Group of Young Overweight and Obese Women

The aim of this study was to explore the relationships between physical performance variables and bone parameters such as bone mineral density (BMD), bone mineral content, hip geometry indices, and trabecular bone score in a group of young overweight and obese adult women. Sixty-eight overweight/obese (body mass index ≥25 kg/m²; 25.5-42.4 kg/m²) young women whose ages range from 18 to 35 yr participated in this study. Body composition and bone outcomes were measured by dual-energy X-ray absorptiometry. Maximum oxygen consumption (VO₂ max, in liter per minute) was determined indirectly using a progressive shuttle run test. One-repetition-maximum half-squat was directly measured. Vertical jump was measured and maximum power (P max) of the lower limbs was calculated. Lean mass was positively correlated to whole body (WB) BMD, total hip BMD, femoral neck (FN) BMD, femoral neck cross-sectional area (FN CSA) and femoral neck cross sectional moment of inertia (FN CSMI) (p < 0.05). VO₂ max (in liter per minute) and muscle power were positively correlated to WB BMD, total hip BMD, FN BMD, FN CSA, and FN CSMI (p < 0.05). One-repetition-maximum half-squat was positively correlated with lumbar spine trabecular bone score, WB BMD, FN BMD, FN CSA and FN CSMI (p < 0.05). This study suggests that lean mass, vertical jump, VO₂ max (liter per minute), muscle power and one-repetition-maximum half squat are positive determinants of BMD and hip geometry indices in young overweight and obese women.

Trends in paediatric distal radius fractures: an eight-year review from a large UK trauma unit

INTRODUCTION

This observational study investigated the incidence of distal radius fractures in children, to determine whether the rate is rising, the effect of seasonal variation on incidence and whether fracture type and rate of surgical intervention has changed, to help in determining costs for secondary care and to aid resource allocation.

MATERIALS AND METHODS

All paediatric patients(n = 6529) who sustained a distal radius fracture over an eight-year period (2007-2014) were identified. Poisson regression modelling was used to identify change in trends.

RESULTS

There was no change in distal radius fracture incidence, rate of surgical intervention (P = 0.36) or fracture type (P = 0.70). Overall incidence was 337 fractures per 100,000 patient/years. The highest fracture incidence was seen in older school boys (708 per 100,000 patient/years, P < 0.005). Overall fracture rate was lower in winter (P < 0.005). Incidence is highest in summer and the main variation is related to season.

DISCUSSION

These data can help to predict accurately the number of children presenting to the emergency department with wrist fractures depending on the time of year.

Genome-scale Capture C promoter interactions implicate effector genes at GWAS loci for bone mineral density

Osteoporosis is a devastating disease with an essential genetic component. GWAS have discovered genetic signals robustly associated with bone mineral density (BMD), but not the precise localization of effector genes. Here, we carry out physical and direct variant to gene mapping in human mesenchymal progenitor cell-derived osteoblasts employing a massively parallel, high resolution Capture C based method in order to simultaneously characterize the genome-wide interactions of all human promoters. By intersecting our Capture C and ATAC-seq data, we observe consistent contacts between candidate causal variants and putative target gene promoters in open chromatin for ~ 17% of the 273 BMD loci investigated. Knockdown of two novel implicated genes, ING3 at ‘CPED1-WNT16’ and EPDR1 at ‘STARD3NL’, inhibits osteoblastogenesis, while promoting adipogenesis. This approach therefore aids target discovery in osteoporosis, here on the example of two relevant genes involved in the fate determination of mesenchymal progenitors, and can be applied to other common genetic diseases.

GWAS have identified numerous genetic loci for bone mineral density (BMD) and fracture risk. Here, the authors map these variants to putative target genes using ATAC-seq and Capture C of human osteoblasts and confirm ING3 and EPDR1 as BMD genes in in vitro osteoblast differentiation experiments.

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.

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.

Gait Pattern, Impact to the Skeleton and Postural Balance in Overweight and Obese Children: A Review

The article reviews the biomechanical factors that may cause overweight/obese children to reduce their level of physical activity, while increasing their risk of overuse injuries and exercise-related pain. Recommendations would be to screen those children for any gait or postural impairments before they join any exercise program, and to provide them with specific gait treatments and/or physical exercise programs, in order to decrease their risk for future musculoskeletal injuries and pain.

Fat and bone in children - where are we now?

The risk of fracture secondary to low-impact trauma is greater in obese children, suggesting obese children are at risk of skeletal fragility. However, despite this finding, there is a lack of agreement about the impact of excessive adiposity on skeletal development. The combination of poor diet, sedentary lifestyle, greater force generated on impact through falls, and greater propensity to falls may in part explain the increased risk of fracture in obese children. To date, evidence suggests that in early childhood years, obesity confers a structural advantage to the developing skeleton. However, in time, this relationship attenuates and then reverses, such that there is a critical period during skeletal development when obesity has a detrimental effect on skeletal structure and strength. Fat mass may be important to the developing cortical and trabecular bone compartments, provided that gains in fat mass are not excessive. However, when fat accumulation reaches excessive levels, unfavorable metabolic changes may impede skeletal development. Evidence from studies examining bone microstructure suggests skeletal adaption to excessive load fails, and bone strength is relatively diminished in relation to body size in obese children. Mechanisms that may explain these changes include changes in the hormonal environment, particularly in relation to alterations in adipokines and fat distribution. Given the concomitant rise in the prevalence of childhood obesity and fractures, as well as adult osteoporosis, further work is required to understand the relationship between obesity and skeletal development.

Bone mineral density is compromised in very long-term survivors of irradiated childhood brain tumor

INTRODUCTION

The increase in the number of childhood brain tumor survivors warrants detailed research to increase our knowledge regarding the possible physical and psychosocial adverse outcomes of tumor and tumor therapy. The aim of this study was to evaluate the current bone health by measuring the bone mineral density (BMD) in irradiated, adult long-term survivors of childhood brain tumors.

MATERIAL AND METHODS

We studied a national cohort of 74 adult survivors of childhood brain tumors treated with irradiation in Finland between 1970 and 2008. Dual X-ray absorptiometry (DXA) was performed for the femoral necks, total hips, and lumbar spine. Laboratory tests were conducted for evaluating the pituitary, thyroid, and gonadal functions. The participants were interviewed, examined clinically, and the disease and treatment related data were retrieved from the patient files.

RESULTS

One fourth of the patients (23.6%) had sex- and age-normalized z-scores below the expected range for age (z-score ≤ -2.0). Mean BMD scores were decreased in all the DXA measurement sites. Male sex was associated with low BMD (p < .05), while body mass index (BMI) had a significant positive association with BMD (p < .01). Mode of irradiation (with or without spinal irradiation) or inclusion of chemotherapy in the treatment did not affect BMD significantly. However, patients with a ventriculoperitoneal shunt had lower BMD than those without a shunt (p < .05). Follicle stimulating hormone (FSH) and luteinizing hormone (LH) were negatively associated with BMD in women (p < .05). However, a higher cumulative dose of glucocorticoids during treatment was not associated with lower BMD, while low BMD was significantly associated with previous fractures in long bones.

DISCUSSION

Low BMD should be taken in consideration in treatment of irradiated childhood brain tumor survivors especially in those with previous fractures in long bones.

Abdominal obesity adversely affects bone mass in children

AIM

To determine the effect of childhood obesity and insulin resistance on bone health.

METHODS

We conducted a cross sectional study in pubertal adolescents and young adults 13-20 years old who were either overweight/obese or normal weight. Participants were Tanner 3 or above for pubertal stage, and had fasting blood work done to measure glucose, insulin, C-reactive protein and lipid levels. Homeostatic model of insulin resistance (HOMA-IR) was calculated using the formula (Fasting Blood Glucose *Insulin/405). Body composition and bone mineral density were measured using dual energy X-ray absorptiometry (DXA; Hologic QDR 4500, Waltham, MA, United Kingdom).

RESULTS

Percent trunk fat was associated inversely with whole body bone mineral content (BMC), whereas HOMA-IR was associated positively with whole body BMC.

CONCLUSION

Our results suggest that abdominal adiposity may have an adverse effect on whole body bone parameters and that this effect is not mediated by insulin resistance.

Bone Strength in Girls and Boys After a Distal Radius Fracture: A 2-Year HR-pQCT Double Cohort Study

We recently reported impaired bone strength in girls with low- to moderate-energy distal radius fractures (Fx) compared with girls with no history of forearm fractures (Non-Fx). We aimed to determine whether bone strength deficits observed at baseline were still present after 2 years. We assessed bone strength, microarchitecture, and bone mineral density (BMD) of the non-fractured (Fx) and non-dominant (Non-Fx) distal radius (7% site) at baseline, 12, and 24 months using high-resolution pQCT (Scanco Medical, Brüttisellen, Switzerland) in 104 girls (aged 11.0 ± 1.7 years; 47 Fx, 57 Non-Fx) and 157 boys (aged 12.7 ± 1.7 years; 86 Fx, 71 Non-Fx). Bone outcomes included total area (Tt.Ar) and bone mineral density (Tt.BMD), trabecular bone volume ratio (BV/TV), thickness (Tb.Th), separation (Tb.Sp), and number (Tb.N), and cortical BMD (Ct.BMD), thickness (Ct.Th), and porosity (Ct.Po). We used finite element analysis to estimate bone strength (failure load [F.Load]; ultimate stress [U.Stress]; load-to-strength ratio). We used sex-specific mixed-effects models to compare bone outcomes between Fx and Non-Fx over 2 years. In girls, those with fractures had 18% to 24% lower U.Stress and 5% to 9% lower Tt.BMD than Non-Fx at all time points (p < 0.017). In secondary analysis by fracture degree, girls with low-energy (LE) fractures had 19% to 21% lower F.Load, 25% to 47% lower U.Stress, 11% to 14% lower Tt.BMD, and 11% to 15% lower BV/TV than Non-Fx at all time points (p < 0.017). In contrast, boys' bone outcomes were similar between Fx and Non-Fx at all time points. In secondary analysis by fracture degree, boys with LE fractures had 10% lower Tt.BMD and 10% lower Ct.Th compared with Non-Fx at 12 months only. Deficits in distal radius bone strength and trabecular bone microarchitecture appear to track across 2 years after a forearm fracture in girls but not in boys. Longer follow-up is needed to determine whether deficits persist into adulthood in women and how they may influence future risk of fragility fracture. © 2017 American Society for Bone and Mineral Research.