Bone fractures in children: is there an association with obesity?

Children's foot parameters and basic anthropometry - do arch height and midfoot width change?

The aims of this study were as follows: (1) to assess how foot posture and morphology assessments change according to body mass index (BMI) status; (2) to determine which body composition parameter (BMI or waist circumference) correlates better with the foot posture index (FPI), arch height index (AHI), and midfoot width (MFW) in children. Foot morphometry (FPI, AHI, and MFW) and body composition (BMI and waist circumference (WC)) were assessed in a cross-sectional study of 575 children (mean age = 7.42 ± 1.67 years; 53.27% female). When comparing BMI groups, an increase of 8.3% in AHI and 13.6% in MFW (both p < 0.0001) was seen. In linear regression analyses, BMI and WC were positively associated with MFW explaining together 64.8% of its variance. Noteworthy, MFW is the most related to body composition parameters.

CONCLUSION

Foot morphology assessed by FPI, AHI, and MFW differs among BMI categories in children. Noteworthy, WC correlates better with foot measures than does the more commonly used BMI, and more importantly the MFW is the foot measure best explained by children's body weight. Since foot morphometry is different among different BMI groups, children would benefit from shoes with different patterns (thinner and wider), as well as a good system to adjust midfoot height.

WHAT IS KNOWN

• Children who are overweight and obese have flatter feet, when assessed using footprints. • Up to 72% of people have incorrectly fitted shoes.

WHAT IS NEW

• Children with underweight have thinner and flatter feet than children with normal weight, while children with overweight and obesity have wider and higher arched feet. • Body weight is related to foot shape, which has relevance for footwear manufacturers.

Adolescent tibial tubercle fractures in the time of the COVID 19: A single orthopedic trauma center experience

BACKGROUND

The purpose of this study is to assess the incidence and clinical characteristics of adolescent tibial tubercle fractures (TTFs) during the COVID-19 pandemic by sharing our experiences.

METHODS

Pediatric patients aged between 0 and 18 years old with confirmed diagnosis of TTFs who were treated at our center between April 2020 and May 2020 were included in the study. In addition to demographics, mechanism injury, treatment modalities, complications were also noted.

RESULTS

Sixteen patients were included in the study. The mean age was 14.8 ± 0.9 years (range: 13-16 years). The mean BMI of patients was 26.3 ± 2.3 kg/m² (range: 23.2-30.4 kg/m²). According to the BMI-for-age percentiles growth chart, eight patients (50%) were overweight, and eight patients (50%) were at a risk of being categorized as overweight. The most common cause for the injury was jumping due to basketball (50%). Twelve of 16 patients were treated operatively by open reduction and internal fixation. The remaining 4 patients were treated non-operatively with long leg cast.

CONCLUSION

The incidence of TTFs was 16 cases over about two months during the pandemic isolation period. Our results demonstrated that all adolescent TTFs occurred during periods when outdoor activities were permitted. This finding may be explained by sudden athletic activity after prolonged immobilization. We observed that all of our patients were male and either overweight or at risk of being overweight.

A Target Population Derived Method for Developing a Competency Standard in Radiograph Interpretation

CONSTRUCT

For assessing the skill of visual diagnosis such as radiograph interpretation, competency standards are often developed in an ad hoc method, with a poorly delineated connection to the target clinical population.

BACKGROUND

Commonly used methods to assess for competency in radiograph interpretation are subjective and potentially biased due to a small sample size of cases, subjective evaluations, or include an expert-generated case-mix versus a representative sample from the clinical field. Further, while digital platforms are available to assess radiograph interpretation skill against an objective standard, they have not adopted a data-driven competency standard which informs educators and the public that a physician has achieved adequate mastery to enter practice where they will be making high-stakes clinical decisions.

APPROACH

Operating on a purposeful sample of radiographs drawn from the clinical domain, we adapted the Ebel Method, an established standard setting method, to ascertain a defensible, clinically relevant mastery learning competency standard for the skill of radiograph interpretation as a model for deriving competency thresholds in visual diagnosis. Using a previously established digital platform, emergency physicians interpreted pediatric musculoskeletal extremity radiographs. Using one-parameter item response theory, these data were used to categorize radiographs by interpretation difficulty terciles (i.e. easy, intermediate, hard). A panel of emergency physicians, orthopedic surgeons, and plastic surgeons rated each radiograph with respect to clinical significance (low, medium, high). These data were then used to create a three-by-three matrix where radiographic diagnoses were categorized by interpretation difficulty and significance. Subsequently, a multidisciplinary panel that included medical and parent stakeholders determined acceptable accuracy for each of the nine cells. An overall competency standard was derived from the weighted sum. Finally, to examine consequences of implementing this standard, we reported on the types of diagnostic errors that may occur by adhering to the derived competency standard.

FINDINGS

To determine radiograph interpretation difficulty scores, 244 emergency physicians interpreted 1,835 pediatric musculoskeletal extremity radiographs. Analyses of these data demonstrated that the median interpretation difficulty rating of the radiographs was -1.8 logits (IQR -4.1, 3.2), with a significant difference of difficulty across body regions (p < 0.0001). Physician review classified the radiographs as 1,055 (57.8%) as low, 424 (23.1%) medium or 356 (19.1%) high clinical significance. The multidisciplinary panel suggested a range of acceptable scores between cells in the three-by-three table of 76% to 95% and the sum of equal-weighted scores resulted in an overall performance-based competency score of 85.5% accuracy. Of the 14.5% diagnostic interpretation errors that may occur at the bedside if this competency standard were implemented, 9.8% would be in radiographs of low-clinical significance, while 2.5% and 2.3% would be in radiographs of medium or high clinical significance, respectively.

CONCLUSION(S)

This study's novel integration of radiograph selection and a standard setting method could be used to empirically drive evidence-based competency standard for radiograph interpretation and can serve as a model for deriving competency thresholds for clinical tasks emphasizing visual diagnosis.

Bone Response to High-Intensity Interval Training versus Moderate-Intensity Continuous Training in Adolescents with Obesity

INTRODUCTION

Since adolescents with obesity are prone to bone fragility during weight loss, the aim was to compare the impact of high-intensity interval training (HIIT) versus moderate-intensity continuous training (MICT) on bone density, geometry, and strength.

METHODS

Sixty-one adolescents were randomly assigned to 2 cycling trainings (HIIT and MICT) and a control (CTR, without training) group. Anthropometry, dual-energy X-ray absorptiometry with hip structural analysis and the trabecular bone score (TBS) were assessed before and after the 16-week intervention.

RESULTS

Body mass index (BMI) and fat mass (FM) percentage decreased at T1 versus T0 in both training groups (p < 0.001 for HIIT, p = 0.01 for MICT), though to a larger extent in HIIT (p < 0.05). Total body bone mineral density (BMD) and bone mineral content (BMC) increased in both training groups (p < 0.001), but to a greater extent in HIIT for BMC (p < 0.05). Lumbar spine BMD and BMC increased in both training groups (p < 0.001 for HIIT, p < 0.01 for MICT), with a time × group interaction between HIIT and CTR (p < 0.05) only. TBS increased in both training groups (p < 0.01 for HIIT, p < 0.05 for MICT). Hip BMD and BMC increased in both HIIT (p < 0.001 and p < 0.01) and MICT (p < 0.01 and p < 0.05). At the narrow neck (NN), endocortical diameter, width (p < 0.01), cross-sectional moment of inertia, and section modulus (Z) (p < 0.05) increased only in the HIIT group, such as BMD and Z (p < 0.05) at the intertrochanteric region (IT) and average cortical thickness (p < 0.001) and width (p < 0.05) at the femoral shaft. At the NN and IT, the buckling ratio decreased only in the HIIT group (p < 0.05), predicting higher resistance to fracture.

CONCLUSIONS

In addition to inducing greater BMI and FM percentage decreases in comparison to MICT, HIIT improves multisite bone density, geometry, and strength, which heighten the justification for HIIT as part of weight loss interventions in adolescents with obesity.

Bone Fractures in Children and Young Adults With Type 1 Diabetes: Age Distribution, Fracture Location, and the Role of Glycemic Control

Type 1 diabetes (T1D) is a known risk factor for fractures, but the underlying pathophysiology is still not fully understood. This study aims to define age peaks and frequent fracture sites of children and young adults with T1D. Additionally, associations of fractures with metabolic and lifestyle factors as well as with additional complications in individuals with T1D were analyzed. A total of 750 individuals with T1D aged ≤25 years with fractures were matched to 3750 patients with T1D without fractures by demographics and insulin regimen. Hemoglobin A1c (HbA1c) values were compared using linear regression, and logistic regression was used to calculate odds ratios (OR) for fractures in individuals with acute complications and diseases. Median (Q1-Q3) age was 12.7 (9.9 to 14.9) years in individuals with fractures and 16.3 (12.6 to 17.8) years in the entire control group with 65% versus 53% males. Peak age for fractures was 7 to <15 years in males and 9 to <11 years in females, which is earlier than reported for the general population. HbA1c (%) was significantly higher in individuals with fractures than in controls (difference of estimated means: 0.26%; 95% confidence interval [CI] 0.07-0.46), especially in postpubertal females (0.68; 0.10-1.26). Significantly higher odds for fractures were observed in individuals with severe hypoglycemia (OR = 1.90; 95% CI 1.47-2.47), especially in prepubertal females (OR = 2.81; 1.21-6.52]) and postpubertal males (2.44; 1.11-5.38), celiac disease (2.02; 1.67-2.45), and with a history of smoking (1.38; 1.02-1.88). The age peak of fractures seems to be earlier in T1D than in the general population. Poor glycemic control is related to fractures, even before puberty. Associations of HbA1c and severe hypoglycemia with fractures highly depend on age and sex. © 2021 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

Risperidone versus aripiprazole fracture risk in children and adolescents with autism spectrum disorders

Risperidone and aripiprazole, commonly used antipsychotics in children with autism spectrum disorder (ASD), have previously been associated with elevated fracture risk in other populations. The aim of this study was to evaluate and compare the risk of fracture among children with ASD using risperidone or aripiprazole. This was a retrospective, propensity-score matched cohort study, set between January 2013 and December 2018. We used the MarketScan Medicaid insurance data, which covers multiple states of the United States. We included ASD children aged 2-18 years, who were new users of aripiprazole or risperidone and with no prior history of antipsychotic use or fractures. The main exposure was the continued use of aripiprazole or risperidone. The incidence rates of any fracture during follow-up were evaluated, and the risk between aripiprazole and risperidone was compared via Cox-proportional hazard models. Results were stratified by age, sex, duration of exposure and fracture site. In total, 3312 patients (78% male; mean [SD] age 11.0 [3.7] years) were identified for each cohort. Over the full duration of follow-up, fracture incidence rates per 1000 patient-years were 23.2 for risperidone and 38.4 for aripiprazole (hazard ratio and 95% confidence interval: 0.60 [0.44-0.83]). Risks were similar between cohorts throughout the first 180 days on treatment, but significantly higher in the aripiprazole group thereafter. Extremity fractures drove most of the increased risk, with the biggest differences in lower leg and ankle fractures. Differences widened for children aged 10 years or younger (HR [95% CI]: 0.47 [0.30-0.74]). In conclusion, compared to aripiprazole, risperidone was associated with 40% lower risk of fracture. Further analysis on the mechanism and long-term bone health of antipsychotic-treated children with ASD is warranted. LAY SUMMARY: We compared the risk of bone fractures among 6624 children with autism spectrum disorder (ASD), half of whom used risperidone and half of whom used aripiprazole. Taking other factors into account, risks were similar between the two groups throughout the first 180 days on treatment, but significantly higher in the aripiprazole group thereafter. The biggest differences were in lower leg and ankle fractures. Overall, compared with aripiprazole, risperidone was associated with 40% lower risk of fracture.

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.

Bone response to eccentric versus concentric cycling in adolescents with obesity

OBJECTIVES

Because adolescents with obesity are susceptible to bone fragility during weight loss (WL), we evaluated the impact of eccentric (ECC) versus classical concentric (CON) training at the same oxygen consumption (V˙O₂) on bone density, geometry and strength.

METHODS

Thirty five adolescents were included into 2 training (CON and ECC cycling) and a control (CTR, without training) groups. Anthropometry, dual-energy X-ray absorptiometry, hip structural analysis and quantitative bone ultrasound were assessed before and after the 12-week intervention.

RESULTS

The trainings promoted significant improvements in body mass index, total fat (FM) and lean mass (LM), with better improvements for FM and LM in the ECC group (p < 0.05). Leg LM percentage increased only in the ECC group (p < 0.05). Total body bone mineral content and density increased in both training groups (p < 0.001) with significant time x group interactions only between ECC and CTR (p < 0.05). Buckling ratio at the intertrochanteric region and femoral shaft increased only in CTR and CON groups (p < 0.05). Speeds of sounds at the calcaneum increased only in ECC group (p < 0.01).

CONCLUSIONS

Bone fragility, from a compromised relationship between density, geometry and strength, might be prevented with the ECC modality.

Clinical and epidemiological features of tibial tubercle avulsion fracture in Chinese adolescents

Background

Tibial tubercle avulsion fracture is rare in children. Accumulated knowledge on clinical and epidemiological features of this fracture is of practical significance for clinical colleagues to deal effectively with such fractures.

Methods

Clinical and epidemiological parameters were reviewed retrospectively in 29 patients with tibial tubercle avulsion fracture that was treated in our hospital in the past 7 years.

Results

Totally, 29 children with 30 tibial tubercle fractures were enrolled. They were all boys; the average age was 13.8 (12–15) years, and the average Body Mass Index (BMI) was 26.4 (19.2–34.3). Statistically, 41.4% of injuries occurred during jumping activities, and 1 (3.4%), 12 (41.4%) and 16 (55.2%) patients were injured bilaterally, on the right and left sides, respectively. The patients were classified into type I (4), II (3), III (13) and IV (10) fractures. Two patients (three knees) with fractures of type IV received close reduction and cast immobilization for 6 weeks. One patient with fracture of type IV underwent close reduction and was fixed with two cannulated screws. The remaining 26 patients underwent open reduction and were fixed with two or three cannulated screws. The average follow-up time was 38 (14–98) months; no complication was noted. Twenty-seven patients had an excellent outcome.

Conclusion

In Chinese adolescents, the tibial tubercle avulsion fracture predisposes to boys with higher body weight; jumping is the most common cause of injury; treatments show satisfactory outcome regardless of fracture types.

Adverse Events from Emergency Physician Pediatric Extremity Radiograph Interpretations: A Prospective Cohort Study

OBJECTIVES

We determined how often emergency physician pediatric musculoskeletal (MSK) radiograph interpretations were discordant to that of a radiologist and led to an adverse event (AE). We also established the variables independently associated with this outcome.

METHODS

This prospective cohort study was conducted in an urban, tertiary care children's emergency department (ED). We enrolled children who presented to an ED with an extremity injury and received radiographs. ED physicians documented their radiograph interpretation, which was compared to a radiology reference standard. Patients received telephone follow-up and had institutional medical records reviewed in 3 weeks. An AE occurred if there were clinical sequelae and/or repeat health care visits due to a delay in correct radiograph interpretation.

RESULTS

We enrolled 2,302 children (mean [±SD] age = 9.0 [4.4] years; 1,288 (56.0%) male]. Of these, 180 (7.8%; 95% confidence interval = 6.8 to 9.0) ED physician discordant interpretations resulted in an AE. Specifically, there were no negative clinical outcomes; however, relative to cases diagnosed correctly at the index ED, patients whose fracture was not initially identified encountered 77.2% more subsequent ED visits, while those falsely diagnosed with a fracture experienced 41.5% additional orthopedic clinic visits. Odds of an ED discrepant interpretation was significantly higher if a physician's pretest probability of a fracture was ≤ 20% versus> 20% (adjusted odds ratio [aOR] = 1.6), patient's pain score was ≤ 2 versus> 2 (aOR = 1.6), and injury was located in a joint versus other location (aOR = 1.7).

CONCLUSIONS

Emergency physician discordant pediatric MSK radiograph interpretations that resulted in an AE occurred with regular frequency in a pediatric ED setting. AEs were primarily an increase in subsequent health care visits. Importantly, a low clinical suspicion for a fracture or injury located in the joint were risk factors for ED physician discordant interpretations.

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.

Weight-for-Age Percentile as a Pediatric Predictor of Emergency Department Outcome

This study is a retrospective cohort study that examines the association between weight-for-age percentile and pediatric admission incidence from the emergency department (ED) for all diagnoses. The charts of 1432 pediatric patients under 18 years with ED visits from 2013 to 2015 at a tertiary children’s hospital were reviewed. Analyses of subject age/weight stratifications were performed, along with ED disposition, reason for visit, and Emergency Severity Index (ESI). Multivariable logistic regression models were used to evaluate the independent effect of weight-for-age percentile on ED disposition while controlling for age, ESI, and reason for visit. Underweight subjects were more likely to be admitted than their normal weight counterparts when analyzed overall (odds ratio [OR] = 2.58, P < .01) and by age: less than 2.0 years of age (OR = 2.04, P = .033), between 2.01 and 6.0 years of age (OR = 8.60, P = .004), and between 6.01 and 13.0 years of age (OR = 3.83, P = .053). Younger age (OR = 0.935, P < .001) and higher acuity (OR = 3.49, P < .001) were also significant predictors of admission. No significant associations were found between weight and likelihood of admission for patients older than 13.01 years or between overweight/obese weight categories and admission for any age subgroups. This study suggests that underweight children younger than 13 years are at higher risk to be admitted from the ED than their normal weight, overweight, and obese counterparts. Even when controlling for other key factors, such as the ESI, a lower weight-for-age percentile was a reliable predictor of hospitalization.

Tibial tubercle avulsion fracture according to different mechanisms of injury in adolescents: Tibial tubercle avulsion fracture

Tibial tubercle avulsion fracture caused by knee extensor is very rare; furthermore, non-traumatic fractures during running or bilateral fractures have been reported. The purpose of this study was to evaluate any differences according to the mechanisms of injury in adolescents with tibial tubercle avulsion fracture.Thirty patients with tibial tubercle avulsion fractures were reviewed and the average age was 13 years 1 month. Seven patients (low-stress group) had a spontaneous fracture during running without definite trauma. Twenty-three patients (high-stress group) experienced pain during jumping and landing, or definite trauma. The mechanisms of injury, age, height, weight, body mass index (BMI), BMI percentile, fracture type, as well as any complication, such as limitation of motion and deformity related to the physeal arrest, were compared between groups.There was no definite difference in age, fracture type, and surgical outcomes between groups. There was no patient with significant early physeal arrest in both groups. The weight (P = .02), BMI (P = .03) and BMI percentile (P = .01) in low-stress group were higher than those in high-stress group. In low-stress group, 6 patients' BMIs were in the 97th percentile, and 1 patient's BMI was in the 5th percentile.Extreme BMI may be a risk factor for tibial tubercle avulsion fractures in adolescents during running without definite trauma. However, there was no difference in the final outcome according to injury mechanisms.

Comparison of Resource Utilization and Length of Hospitalization Between Overweight and Healthy-Weight Pediatric Trauma Patients Presenting to a Pediatric Emergency Department With Moderate to Severe Injury: A Prospective Study

OBJECTIVES

Our study aimed to compare overweight and healthy-weight pediatric trauma patient outcomes, specifically with respect to hospital length of stay and resource utilization. We hypothesized that overweight pediatric trauma patients would have increased hospital length of stay and radiographic study use compared with their healthy-weight counterparts.

METHODS

This was a prospective, observational, cohort study of pediatric trauma patients aged 2 to 19 years presenting to an urban pediatric emergency department over a period of 1 year. Using measured height and weight values, body mass index (BMI) for age was calculated and plotted on the Centers for Disease Control and Prevention BMI-for-age growth charts. Patients were followed up throughout their hospitalization, and the following items were recorded: trauma alert level, mechanism of injury, age, sex, race, Glasgow Coma Scale score, total number of days in hospital, total number of intensive care unit days, total number of radiographs obtained, total number of computed tomography scans obtained, and mechanism of injury.

RESULTS

Our study population included 109 subjects. The mean age of the subjects was 9.7 years. The number of patients meeting the definition of obese (BMI for age ≥95%) was 15, or 14% of the total study population. There was no significant difference between the overweight cohort and the healthy-weight cohort found among any of the variables recorded and analyzed.

CONCLUSIONS

Although there are many chronic conditions in children associated with obesity, in the case of trauma, it does not seem to be a strong concern. A continued focus on preventing and reversing childhood obesity for other physical and mental health outcomes may be more important.

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.

Effect of cardiometabolic risk factors on the relationship between adiposity and bone mass in girls

BACKGROUND/OBJECTIVE

Childhood obesity has been separately associated with cardiometabolic risk factors (CMRs) and increased risk of fracture. However, both augmented and compromised bone mass have been reported among overweight/obese children. Metabolic dysfunction, often co-existing with obesity, may explain the discrepancy in previous studies. The aim of this study was to examine whether the relationship between adiposity and dual-energy X-ray absorptiometry (DXA) derived bone mass differed in young girls with and without CMR(s).

SUBJECTS/METHODS

Whole-body bone and body composition measures by DXA and measures of CMR (fasting glucose, high-density lipoprotein cholesterol (HDL-C), triglyceride (TG), systolic and diastolic blood pressure, waist circumference (WC)) were obtained from 307, 9- to 12-year-old girls. Girls with 1 or ≥ 2 CMR(s) were considered to be at risk (vs. no CMR). Multiple linear regression was used to test the relationship of total fat mass with total body bone mineral content (BMC) after controlling for height, lean mass, CMR risk, and other potential confounders.

RESULTS

There was a significant interaction between CMR risk and total body fat mass. When girls were stratified by CMR group, all groups had a significant positive relationship between fat mass and BMC (p < 0.05), however, girls with ≥ 2 CMRs had a lower BMC for a given level of body fat. Total body fat was not significantly related to bone mineral density (p > 0.05).

CONCLUSION

Fat mass has a positive relationship with BMC even after controlling for lean mass. However, the positive relationship of fat mass with BMC may be attenuated if multiple CMRs are present.

A Memory of Early Life Physical Activity Is Retained in Bone Marrow of Male Rats Fed a High-Fat Diet

Studies have reported opposing effects of high-fat (HF) diet and mechanical stimulation on lineage commitment of the bone marrow stem cells. Yet, how bone marrow modulates its gene expression in response to the combined effects of mechanical loading and a HF diet has not been addressed. We investigated whether early-life (before onset of sexual maturity at 6 weeks of age) voluntary physical activity can modulate the effects of a HF diet on male Sprague Dawley rats. In the bone marrow, early-life HF diet resulted in adipocyte hypertrophy and a pro-inflammatory and pro-adipogenic gene expression profile. The bone marrow of the rats that undertook wheel exercise while on a HF diet retained a memory of the early-life exercise. This memory lasted at least 60 days after the cessation of the voluntary exercise. Our results are consistent with the marrow adipose tissue having a unique response to HF feeding in the presence or absence of exercise.

The Impact of Fat and Obesity on Bone Microarchitecture and Strength in Children

A complex interplay of genetic, environmental, hormonal, and behavioral factors affect skeletal development, several of which are associated with childhood fractures. Given the rise in obesity worldwide, it is of particular concern that excess fat accumulation during childhood appears to be a risk factor for fractures. Plausible explanations for this higher fracture risk include a greater propensity for falls, greater force generation upon fall impact, unhealthy lifestyle habits, and excessive adipose tissue that may have direct or indirect detrimental effects on skeletal development. To date, there remains little resolution or agreement about the impact of obesity and adiposity on skeletal development as well as the mechanisms underpinning these changes. Limitations of imaging modalities, short duration of follow-up in longitudinal studies, and differences among cohorts examined may all contribute to conflicting results. Nonetheless, a linear relationship between increasing adiposity and skeletal development seems unlikely. Fat mass may confer advantages to the developing cortical and trabecular bone compartments, provided that gains in fat mass are not excessive. However, when fat mass accumulation reaches excessive levels, unfavorable metabolic changes may impede skeletal development. Mechanisms underpinning these changes may relate to changes in the hormonal milieu, with adipokines potentially playing a central role, but again findings have been confounding. Changes in the relationship between fat and bone also appear to be age and sex dependent. Clearly, more work is needed to better understand the controversial impact of fat and obesity on skeletal development and fracture risk during childhood.

Impact of attention deficit hyperactivity disorder therapy on fracture risk in children treated in German pediatric practices

Two thousand eight hundred ninety-four children and adolescents treated by 243 pediatricians were analyzed. Patients receiving attention deficit hyperactivity disorder (ADHD) medications were at a lower risk of fractures than patients without ADHD medications. The strongest impact was in the age group of 6-9 years. Finally, there was a significant association between therapy duration and fracture risk.

INTRODUCTION

The aim of this study was to analyze the impact of ADHD therapy on fracture risk in children treated by German pediatricians.

METHODS

Children and adolescents initially diagnosed with ADHD and fractures between 2010 and 2015 were identified by 243 pediatricians. In this nested case-control study, each ADHD case with a fracture was matched (1:1) to an ADHD control without a fracture for age, gender, index year, and physician. In total, 2894 individuals were available for analysis. The main outcome of the study was the risk of fracture as a function of ADHD therapy. Multivariate logistic regression models were created to determine the effect of ADHD therapy on the risk of fracture in the entire population and in three age-specific subgroups.

RESULTS

Patients receiving ADHD medications were at a lower risk of fracture than patients without ADHD medications (OR = 0.61). The impact of ADHD therapy on the risk of fracture was stronger in the age group of 6-9 years (OR = 0.41) than in the age groups of 10-13 years (OR = 0.68) and 14-17 years (OR = 0.74). Finally, a significant correlation was found between therapy duration and fracture risk (OR = 0.71 per month).

CONCLUSION

ADHD therapy was associated with a decrease in the risk of fracture in children and adolescents treated by German pediatricians.

Differences in childhood adiposity influence upper limb fracture site

INTRODUCTION

Although it has been suggested that overweight and obese children have an increased risk of fracture, recent studies in post-menopausal women have shown that the relationship between obesity and fracture risk varies by fracture site. We therefore assessed whether adiposity and overweight/obesity prevalence differed by upper limb fracture site in children.

METHODS

Height, weight, BMI, triceps and subscapular skinfold thickness (SFT) were measured in children aged 3-18 years with an acute upper limb fracture. Data was compared across three fracture sites (hand, forearm and upper arm/shoulder [UA]), and to published reference data.

RESULTS

401 children (67.1% male, median age 11.71 years, range 3.54-17.27 years) participated. 34.2%, 50.6% and 15.2% had fractures of the hand, forearm and UA, respectively. Children with forearm fractures had higher weight, BMI, subscapular SFT and fat percentage z-scores than those with UA fractures (p<0.05 for all). SFT and fat percentage z-scores were also higher in children with forearm fractures compared to hand fractures, but children with hand and UA fractures did not differ. Overweight and obesity prevalence was higher in children with forearm fractures (37.6%) than those with UA fractures (19.0%, p=0.009). This prevalence was also higher than the published United Kingdom population prevalence (27.9%, p=0.003), whereas that of children with either UA (p=0.13) or hand fractures (29.1%, p=0.76) did not differ. These differences in anthropometry and overweight/obesity prevalence by fracture site were evident in boys, but not present in girls.

CONCLUSION

Measurements of adiposity and the prevalence of overweight/obesity differ by fracture site in children, and in particular boys, with upper limb fractures.

Childhood obesity, bone development, and cardiometabolic risk factors

Osteoporosis and obesity are both major public health concerns. It has long been considered that these are distinct disorders rarely found in the same individual; however, emerging evidence supports an important interaction between adipose tissue and the skeleton. Whereas overweight per se may augment bone strength, animal studies suggest that the metabolic impairment that accompanies obesity is detrimental to bone. Obesity during childhood, a critical time for bone development, likely has profound and lasting effects on bone strength and fracture risk. This notion has received little attention in children and results are mixed, with studies reporting that bone strength development is enhanced or impaired by obesity. Whether obesity is a risk factor for osteoporosis or childhood bone health, in general, remains an important clinical question. Here, we will focus on clarifying the controversial relationships between childhood obesity and bone strength development, and provide insights into potential mechanisms that may regulate the effect of excess adiposity on bone.