Dual-energy X-ray absorptiometry interpretation and reporting in children and adolescents: the revised 2013 ISCD Pediatric Official Positions

The association between dietary inflammatory index and bone health in US adolescents: Analysis of the NHANES data

Introduction

Adolescents with a lower peak bone mineral density (BMD) and bone mineral content (BMC) have an elevated risk of osteoporosis in adulthood. The impact of diet on bone health, particularly its role in managing inflammation, which is a key factor in bone health, is gaining wider recognition. Despite evidence that anti-inflammatory diets can enhance bone health, the link between the dietary inflammatory index (DII) and bone health among US adolescents has not been thoroughly investigated. This study aimed to evaluate the correlation between DII score and bone health in this population.

Methods

This cross-sectional study used data from the National Health and Nutrition Examination Survey (NHANES) of US adolescents aged 12-18 years, spanning surveys from 2001 to 2018. The DII was derived from dietary recall data obtained through questionnaire interviews. Bone health was assessed through total body less head (TBLH) BMD and BMC z-scores and lumbar spine bone mineral apparent density for age (BMADa).

Results

The study comprised 8773 adolescents with a mean age of 14.94 ± 1.97 years, 52.2 % were male. Multivariate linear regression analysis revealed a negative correlation between DII and lumbar spine BMADa (β = -0.000003, 95 % confidence interval [CI], -0.000005 to -0.000001; P = 0.001).This significant association remained robust when DII was treated as a categorical variable. Compared with individuals in quartile 1(Q1) DII scores (-3.71 to 1.04), those in Q4 (3.37 to 5.04) had lower BMADa, with a regression coefficient of -0.00002 (95 % CI, -0.00003 to -0.000007, P < 0.001). DII was negatively correlated with TBLH BMC z-scores; however, the difference was not statistically significant. Subgroup analyses showed that DII was associated with lumbar spine BMADa and TBLH BMC z-scores in participants who were male, non-black, with a higher educational level, with a high family income, and underweight to normal weight. We found no significant association between DII and TBLH BMD z-scores.

Conclusion

The findings from this cross-sectional analysis indicate a significant association between the DII and bone health among adolescents in the US, with a notable impact in males and non-black. These insights underscore the importance of adopting dietary patterns to mitigate inflammation and to support optimal bone health and metabolism.

Outpatient Management of Clinical Comorbidities in Children With Cerebral Palsy in Low- and Middle-Income Countries

BACKGROUND

Cerebral palsy (CP) is the most common physical disability of childhood. Its prevalence in low-and middle-income countries (LMICs) is over 3/1000 live births, about double the 1.6/1000 in high income countries (HICs). Multimorbidity is highly prevalent in CP. In LMICs, there are higher rates of prevalence, severity, comorbidities and mortality in children with CP. The evidence base for the recommendations in CP emanates overwhelmingly from studies conducted in HICs. Research conducted in LMICs settings, involving local clinicians, considering local context and investigating local solutions are urgently needed.

METHODS

This scoping review aimed to identify and synthesise current evidence on management of clinical comorbidities in children with CP in LMICs. The Joanna Briggs Institute guidelines were followed for the data extraction and analysis phases. The following questions guided the scoping review: What are the main clinical comorbidities in children with CP? What are the gold standards for diagnosis and treatment of these comorbidities? What options do we have to diagnose and treat these comorbidities in LMICs when gold standards are not available?

RESULTS

A total of 22 188 citations were identified by our search strategy, with 21 380 remaining after the removal of 808 duplicates. After screening titles and abstracts, 1918 citations progressed to full text review. A total of 194 articles met the eligibility criteria and were included in the review. The guiding questions of the review were answered for the following morbidities: respiratory impairments, dysphagia and aspiration, gastroesophageal reflux disease, drooling, obstructive sleep apnea syndrome, malnutrition, constipation, epilepsy, sleep disorders, spasticity, dystonia, pain, hip disorders, scoliosis and osteoporosis.

CONCLUSION

This article highlights the need for interventions adapted to the realities of LMICs. Empowering paediatricians and healthcare professionals in LMICs is crucial for early diagnosis and proactive interventions. Specific guidelines for LMICs can better guide professionals in managing these complex conditions.

Development of bone mineral density and content in children with cerebral palsy: a retrospective, longitudinal study

OBJECTIVES

The aim of this study was to investigate long-term bone development in children with cerebral palsy (CP) using longitudinal measurements of total body less head bone mineral content (TBLH-BMC) and bone mineral density (TBLH-BMD).

METHODS

A retrospective longitudinal analysis was performed on 109 children with CP who participated in a rehabilitation programme from 2006 to 2018. Dual-energy X-ray absorptiometry (DXA) scans were performed at the beginning of the programme and repeated as clinically indicated. The study used SITAR growth curve analysis and the LMS method within the GAMLSS model to generate developmental trajectories for TBLH-BMC and TBLH-BMD.

RESULTS

The findings suggest that the expected developmental trajectories of TBLH-BMC and TBLH-BMD in children with CP approximately follow the third percentile of healthy children. The median annual increase in bone mineral density was similar between GMFCS I-II and III-V groups at 5.12 and 5.79 %, respectively. Girls with CP reached age at peak velocity (APV) earlier than boys. The intensive exercise programme may have contributed to greater annual bone growth in children with more severe CP.

CONCLUSIONS

Children with CP have bone growth trajectories close to the third percentile of their healthy peers, suggesting that age-adjusted z-scores for TBLH-BMC and BMD remain relatively stable throughout childhood and adolescence. Early and targeted interventions, including improving muscle strength and mobility and optimising nutritional and hormonal status, are essential to promote better bone health and quality of life in children with CP.

Advances in the estimation of body fat percentage using an artificial intelligence 2D-photo method

There is a growing need to evaluate the agreement between the field methods and integrate artificial intelligence (AI) using two-dimensional (2D) photos for enhanced real-world analysis. This study evaluated the agreement between AI-2D photos and the clinical reference method, dual-energy X-ray absorptiometry (DXA) to estimate the body fat percentage (BFP). Other methods were also investigated, including skinfolds, A-mode ultrasound, and bioelectrical impedance analysis (BIA). This cross-sectional study was conducted on 1273 adults of both sexes. The Bland-Altman plots, Lin's Correlation Coefficient of Agreement (CCC), and error analyses were calculated. AI-2D photos demonstrated substantial agreement with DXA presenting the highest agreement (CCC ≥ 0.96) among all the investigated methods. InBody-270 and Omron HBF-514 BIA devices showed moderate agreement (CCC = 0.90 to 0.95) for all participants, age groups >30 years, and body mass index >25 kg/m2. AI-2D photos can be interchangeable with DXA, providing a practical, accessible alternative and an easy-to-use system for BFP estimation.

Clinical practice recommendations for the diagnosis and management of X-linked hypophosphataemia

X-linked hypophosphataemia (XLH) is a rare metabolic bone disorder caused by pathogenic variants in the PHEX gene, which is predominantly expressed in osteoblasts, osteocytes and odontoblasts. XLH is characterized by increased synthesis of the bone-derived phosphaturic hormone fibroblast growth factor 23 (FGF23), which results in renal phosphate wasting with consecutive hypophosphataemia, rickets, osteomalacia, disproportionate short stature, oral manifestations, pseudofractures, craniosynostosis, enthesopathies and osteoarthritis. Patients with XLH should be provided with multidisciplinary care organized by a metabolic bone expert. Historically, these patients were treated with frequent doses of oral phosphate supplements and active vitamin D, which was of limited efficiency and associated with adverse effects. However, the management of XLH has evolved in the past few years owing to the availability of burosumab, a fully humanized monoclonal antibody that neutralizes circulating FGF23. Here, we provide updated clinical practice recommendations for the diagnosis and management of XLH to improve outcomes and quality of life in these patients.

The Management of Bone Defects in Rett Syndrome

Rett syndrome (RS) is a rare neurodevelopmental disorder primarily caused by mutations in the X-linked methyl-CpG binding protein 2 (MECP2) gene, responsible for encoding MECP2 which plays a pivotal role in regulating gene expression. The neurological and non-neurological manifestations of RS vary widely in severity depending on the specific mutation type. Bone complications, mostly scoliosis but also osteoporosis, hip displacement, and a high rate of fractures, are among the most prevalent non-neurological comorbidities observed in girls with RS. Low bone mineral density (BMD) is primarily due to a slow rate of bone formation due to dysfunctional osteoblast activity. The use of anticonvulsants, immobilization, low physical activity, poor nutrition, and inadequate vitamin D intake all significantly hamper skeletal maturation and the accumulation of bone mass in RS girls, making them more susceptible to fragility fractures. In RS patients, the upper and lower limbs are the most common sites for fractures which are due to both a reduced BMD and a diminished bone size. This review summarizes the knowledge on risk factors for fragility fracture in patients with RS and proposes a potential diagnostic and therapeutic pathway to enhance low BMD and mitigate the risk of fragility fractures. In particular, this review focused on the importance of clinical and instrumental evaluation of bone status as a basis for adequate planning of nutritional, pharmacological, and surgical interventions to be undertaken. Additionally, the management of bone defects in individuals with RS should be customized to meet each person's specific needs, abilities, and general health.

The role of vitamin D metabolism in regulating bone turnover in adolescents with perinatally-acquired HIV in Southern Africa: a cross-sectional study in Zimbabwe and Zambia

Vitamin D dysregulation can occur in people living with HIV, disrupting calcium homeostasis, and bone turnover. We aimed to investigate the potential mechanisms by which vitamin D regulates bone turnover in adolescents living with perinatally-acquired HIV (ALWH) in Southern Africa. A pre-planned secondary analysis was performed of baseline data from the vitamin D for adolescents with HIV to reduce musculoskeletal morbidity and immunopathology trial (PACTR20200989766029) which enrolled ALWH (11-19 yr) taking antiretroviral therapy for ≥6 mo, and recorded socio-demographic, clinical and dietary data. After over-night fasting, vitamin D metabolites (25(OH)D, 1,25(OH)2D, and 24,25(OH)2D), intact parathyroid hormone (PTH), and bone turnover markers (BTMs) (C-terminal telopeptide of type I collagen (CTX) and procollagen type 1 N-terminal propeptide (P1NP)) were measured. Tandem Mass Spectrometry measured vitamin D metabolites, while intact PTH and BTMs were analyzed by electrochemiluminescence immunoassay. Stratified by 25(OH)D (<75 vs ≥75 nmol/L), associations between standardized concentrations (β = standard deviations) of vitamin D metabolites, intact PTH and BTMs were assessed using structural equations modelling (SEM) adjusted for age, sex, and country (Zimbabwe/Zambia). Among the 842 ALWH enrolled, the median dietary calcium intake was 100 mg (IQR: 55-145). The SEM showed PTH was positively associated (β: 0.21; 95% CI, 0.1, 0.32) with 1,25(OH)2D, only when 25(OH)D was <75 vs ≥75 nmol/L (β: 0.23; 95%CI, -0.13, 0.59), with evidence of an interaction (β: -0.11; 95%CI, -0.20, -0.02). A positive relationship between 25(OH)D and 24,25(OH)2D was seen irrespective of 25(OH)D concentration. 24,25(OH)2D was inversely related to BTMs, particularly when 25(OH)D was <75 nmol/L (CTX: β: -0.15; 95% CI, -0.24, -0.06 and P1NP: β: -0.14; 95%CI, -0.22, -0.06). There was interaction between dietary calcium and 25(OH)D on PTH (β: -0.15; 95% CI, -0.22, -0.07) suggesting an interaction between low 25(OH)D and low dietary calcium which increases PTH. In conclusion, associations between 25(OH)D, PTH, 1,25(OH)2D, and BTMs in ALWH appear dependent upon 25(OH)D concentrations <75 nmol/L and calcium intake. A novel, potentially causal pathway between 25(OH)D, 24,25(OH)2D, and BTMs was seen. Findings enhance understanding of vitamin D metabolism in people living with HIV.

Associations between phthalate metabolites and body composition in children aged 8-19 years

This study aimed to determine the relationship between individual and combined phthalate metabolites and body composition in children and adolescents using data from the 2015-2018 National Health and Nutrition Examination Survey. Single-exposure analysis indicated that most phthalate metabolites were negatively correlated with areal bone mineral density (aBMD). Quantile g-computation demonstrated a negative relationship between the mixture of phthalate metabolites and aBMD, which was confirmed by the Bayesian kernel machine regression model. Sex-stratified analysis revealed that mono-butyl phthalate (MBP) was negatively correlated with aBMD, and MBP, mono-ethyl phthalate (MEP), and mono-isobutyl phthalate (MiBP) were negatively linked to lean mass in males but not in females. The results did not differ according to developmental stages (childhood vs. adolescence). Our findings indicate that phthalate metabolites may affect the body composition in children and adolescents, particularly aBMD. Certain phthalate metabolites seem to be sex-specific, with males showing higher sensitivity than females.

Independent effect of body fat content on inflammatory biomarkers in children and adolescents: The GENOBOX study

BACKGROUND AND AIMS

To assess the relationship between body composition indicators and inflammatory biomarkers in children and adolescents of the GENOBOX study.

METHODS AND RESULTS

Anthropometry data from 264 subjects from the subsample of Zaragoza (Spain) included: weight, height, waist circumference, body mass index and triponderal index. Body composition was determined by Dual-energy X-ray Absorptiometry (DXA), obtaining visceral adipose tissue, fat mass index and lean mass index. Age and sex specific z-scores were computed. Simple linear regression models were performed with inflammatory biomarkers (hsCRP, IL8, TNF-α, adiponectin, leptin and resistin) as dependent variables, and each of the body composition indices as independent variables. Prepubertal boys had higher IL8 and resistin values and pubertal girls had higher HOMA-IR and leptin values. hsCPR and leptin were associated with fat mass, both in prepubertals and pubertals, independently of lean mass, and regardless of how body composition was measured. All body composition indices were inversely associated with adiponectin, except for fat mass index in pubertals, but none of them were statistically significant.

CONCLUSION

A positive association between hsCRP and leptin with all body fat composition parameters, measured by standard nutritional indicators and DXA, was observed in both sexual stages.

Mid-Childhood Plasma Concentrations of Per- and Polyfluoroalkyl Substances, Modifiable Lifestyle Factors, and Bone Mineral Density Through Late Adolescence

There is limited research on associations of per- and polyfluoroalkyl substances (PFAS) with areal bone mineral density (aBMD) through adolescence and whether bone-strengthening factors ameliorate effects. In the Project Viva cohort (N = 484; 50% female), we used sex-stratified linear regression and quantile g-computation mixture models to examine associations of mid-childhood (median: 7.8 years; 2007-2010) plasma PFAS concentrations with a dual-energy X-ray absorptiometry total-body aBMD Z-score in early and late adolescence (median: 12.9 and 17.6 years, respectively). We explored stratum-specific estimates by parent/self-reported physical activity and dairy intake. Using linear mixed models, we evaluated associations with aBMD accrual from mid-childhood through late adolescence. Females with higher perfluorooctanoate (PFOA) and perfluorodecanoate (PFDA) had lower early adolescent aBMD Z-score [e.g., β(95%CI)] per doubling PFOA: -0.19(-0.41, 0.03)]. Youth with higher PFOA and PFDA had lower late adolescent aBMD Z-score, but CIs were wide [e.g., PFOA: females, -0.12(-0.40, 0.16); males, -0.10(-0.42, 0.21)]. Mixture models generally corroborated single PFAS results, and in linear mixed models, females with higher PFAS concentrations, and males with higher PFOA, had slower aBMD accrual. Less active males with higher PFOA, PFDA, and the PFAS mixture had lower late adolescent aBMD Z-score. Some PFAS appeared more negatively associated with the aBMD Z-score among those who consumed less dairy, but there was not consistent evidence of effect modification. Exposure to select PFAS may affect bone accrual through adolescence, with possible resilience conferred by greater physical activity and dairy intake.

Updated reference values for BMD and lean mass measured by DXA in Thai children

INTRODUCTION

This study established normative references for total body less head (TBLH) BMD, lumbar spine (L1-L4) BMD, and both total and appendicular lean mass (LM) in Thai children and adolescents (aged 5-18 years) using DXA. This work expands upon 2014 normative data for Thai children, which included L2-L4 BMD, total body BMD (head included), and total LM.

MATERIALS AND METHODS

We reanalyzed total body and lumbar spine DXA scans (Lunar Prodigy Pro, GE Healthcare; enCORE version 7.53) from 174 boys and 193 girls, using upgraded software (enCORE version 17SP2) for TBLH BMD, L1-L4 BMD, and LM analysis. The "enhanced" mode was applied for TBLH BMD and LM. Adjustments for total and appendicular LM were made relative to squared height (m2) to account for body size variability.

RESULTS

Normative data stratified by sex and Tanner stage were generated for TBLH BMD, L1-L4 BMD, and LM indices. Weight and Tanner stage significantly determined BMD and LM. Adolescent girls exhibited higher LSBMD values due to earlier pubertal onset. Boys showed higher LM indices with more rapid gains during growth spurts.

CONCLUSION

This study provides updated normative reference values for BMD (TBLH and L1-L4) and LM (total and appendicular) in Thai children and adolescents, measured via DXA. These references will enhance the assessment of low bone mass and LM deficits in Thai pediatric populations, particularly in those with chronic illnesses.

Associations of ethnicity, skin tone, and genome-wide sequencing with bone mineral density in adolescents

BACKGROUND

Dual-energy x-ray absorptiometry reference data designate Black and non-Black categories, as higher BMD has been documented among Black youth. We examined associations of race, skin tone, and genetic factors with bone mineral density (BMD).

METHODS

557 adolescents were followed longitudinally. Exposures included race, skin tone, and principal components (PC) from genome-wide arrays. Total body BMD Z-score (BMD-Z) was the primary outcome using linear regression.

RESULTS

359 adolescents identified as non-Hispanic White (NHW) and 75, non-Hispanic Black (NHB). BMD-Z was higher in NHB vs. NHW (β: 0.92 units, 95% CI: 0.64, 1.19) or those with darker skin (0.79, 95% CI: 0.49, 1.08 for brown vs. medium). The first genetic PC (PC1) correlated with identification as NHB. PC1 was associated with higher BMD-Z (0.09, 95% CI: 0.06, 0.12), even after including race (0.07, 95% CI: 0.00, 0.14) or skin tone (0.10, 95% CI: 0.05, 0.15); both race (0.26, 95% CI: -0.49, 1.01 for NHB vs. NHW) and skin tone (-0.08, 95% CI: -0.59, 0.44 for brown vs. medium) no longer predicted BMD-Z after adjustment for PC1.

CONCLUSION

Genetic similarity was robustly associated with BMD, prompting a reevaluation of adolescent BMD reference data to exclude the consideration of race.

IMPACT

Current bone density reference databases include a binary assignment of patients into "Black" and "non-Black" categories, as a higher BMD has been documented among those identifying as Black compared with individuals of other racial and ethnic backgrounds. This study found genetic similarity to be more strongly associated with bone density by dual-energy x-ray absorptiometry than race or skin tone. These data emphasize a need to reevaluate how bone density measurements are interpreted, including exploring reference data that exclude the consideration of race.

Association of per- and polyfluoroalkylated substances/heavy metals and bone health in children and adolescents

Background

Research on the correlation between exposure to per- and polyfluoroalkylated substances (PFASs)/heavy metals and bone health during childhood and adolescence is limited. Considering their role as endocrine disruptors, we examined relationships of six PFASs and three heavy metals with bone mineral density (BMD) in children and adolescents using representative samples from the National Health and Nutrition Examination Survey (NHANES).

Methods

The study included 622 participants aged 12-19. The relationship between single pollutant and lumbar spine and total BMD was studied using linear regression analyses. Additionally, Bayesian Kernel Machine Regression (BKMR) models were applied to assess the joint effects of multiple PFASs and heavy metals exposure on the lumbar spine and total BMD.

Results

Statistically significant differences were noted in the serum concentrations of perfluorooctanoic acid (PFOA), perfluorooctane sulfonic acid (PFOS), perfluorohexane sulfonic acid (PFHxS), blood lead (Pb), and blood manganese (Mn) between male and female participants (all p < 0.05). Single-exposure studies have shown that Mn was negatively correlated with lumbar spine BMD and total BMD. Multivariate linear regression models revealed that, in the male group, total bone density decreased as the blood PFOA levels [95% CI = (-0.031, -0.001), p = 0.040] and blood manganese levels [95% CI = (-0.009, -0.002), p = 0.004] increased. Similarly, lumbar spine bone density decreased as the blood manganese levels [95% CI = (-0.011, -0.002), p = 0.009] increased. In the female group, total bone density decreased as the serum PFNA levels [95% CI = (-0.039, 0.000), p = 0.048] increased. As shown in the BKMR model, the joint effects of pollutant mixtures, including Mn, were negatively associated with both the lumbar spine and total BMD. Among the pollutants analyzed, Mn appeared to be the primary contributor to this negative association.

Conclusion

This study suggests that exposure to certain PFASs and heavy metals may be associated with poor bone health. Childhood and adolescence are crucial stages for bone development, and improper exposure to PFASs and heavy metals during these stages could potentially jeopardize future bone health, consequently raising the risk of osteoporosis in adulthood.

Greater urinary calcium excretion is associated with diminished bone accrual in youth with type 1 diabetes

CONTEXT

The adverse skeletal effects of type 1 diabetes (T1D) include deficient bone accrual and lifelong increased fracture risk. The contributors to impaired bone accrual in people with T1D are incompletely understood.

OBJECTIVE

To determine if urinary calcium excretion is associated with impaired bone accrual in youth with T1D and to characterize the contribution of glycemic control and markers of bone mineral metabolism to urinary calcium excretion.

DESIGN

Observational study.

PARTICIPANTS

50 participants with T1D aged 6-20 years completed a 12-month longitudinal study of bone accrual. A second cohort of 99 similarly aged participants with T1D completed cross-sectional 24-hr urine and blood collections.

MAIN OUTCOME MEASURE

Whole body less head bone mineral content (WBLH BMC) velocity Z-score and fractional excretion of calcium (FeCa).

RESULTS

Participants in the bone accrual cohort had lower WBLH BMC velocity compared to a healthy reference dataset (Z-score -0.3 ± 1.0, p=0.03). FeCa was negatively associated with WBLH BMC velocity Z-score, ρ= -0.47, p=0.001. In the urinary calcium excretion cohort, intact parathyroid hormone (β= -0.4, p=0.01), beta c-telopeptide (β=0.35, p=0.007), and either hemoglobin A1c (HbA1c, β=0.08, p=0.03) or urine fractional glucose excretion (β=0.07, p=0.03) were associated with FeCa in multivariable regression models that included known determinants of urinary calcium excretion.

CONCLUSIONS

Urinary calcium excretion was negatively associated with bone accrual in this cohort of youth with T1D. Mechanistic studies are needed to determine if interventions to reduce urinary calcium excretion could increase bone accrual and reduce skeletal fragility in people with T1D.

Assessing the Muscle-Bone Unit in Girls Exposed to Different Amounts of Impact-Loading Physical Activity-A Cross-Sectional Association Study

BACKGROUND/OBJECTIVES

In children, an association exists between muscle and bone, as well as between physical activity and osteogenesis. Impact loading is a factor in increasing bone accrual during growth. In this work, we explored the muscle-bone association in girls exposed to long-term physical activity at different levels of impact loading.

METHODS

Four groups of girls aged 7-16 were considered. The curricular (C; n = 22) group only had curricular physical activity at school (2 h/w). In addition to curricular physical activity, the girls in the dance (D; n = 21), gymnastics at lower training (GL; n = 14), and gymnastics at higher training (GH; n = 20) groups had 2 h/w, 4 h/w, and 4 h/w < training ≤ 12 h/w additional physical activity, respectively, for at least one year. A visual analysis estimated the respective amounts of impact-loading activity. The bone mineral content (BMC), areal bone mineral density (aBMD), and fat-free soft tissue mass (FFSTM) were assessed with dual-energy X-ray absorptiometry.

RESULTS

The results showed that, after adjusting for several confounders, statistically significant correlations were present between muscle mass and several bone mineral variables. A regression analysis confirmed the correlation in the data, and showed the marginal role of other body composition variables and physical activity for predicting BMC and BMD.

CONCLUSION

Skeletal muscle mass is a major determinant of the BMC and BMD of the TBLH, as well as of the Appendicular level, in girls exposed to different amounts of long-term impact-loading physical activity.

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

Background

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

Methods

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

Results

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

Conclusions

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

The assessment of bone health in children with juvenile idiopathic arthritis; comparison of different imaging-based methods

BACKGROUND

Osteoporosis is increasingly being recognized in children, mostly secondary to systemic underlying conditions or medication. However, no imaging modality currently provides a full evaluation of bone health in children. We compared DXA, a radiographic bone health index (BHI (BoneXpert) and cone-beam CT for the assessment of low bone mass in children with juvenile idiopathic arthritis (JIA).

METHODS

Data used in the present study was drawn from a large multicentre study including 228 children aged 4-16 years, examined between 2015 and 2020. All had a radiograph of the left hand, a DXA scan and a cone-beam CT of the temporomandibular joints within four weeks of each other. For the present study, we included 120 subjects, selected based on DXA BMD and BoneXpert BHI to secure values across the whole range to be tested.

RESULTS

One hundred and twenty children (60.0% females) were included, mean age 11.6 years (SD 3.1 years). There was a strong correlation between the absolute values of BHI and BMD for both total body less head (TBLH) (r = 0.75, p < 0.001) and lumbar spine (L1-L4) (r = 0.77, p < 0.001). The correlation between BHI standard deviation score (SDS) and BMD TBLH Z-scores was weak (r = 0.34) but significant (0 = 0.001), varying from weak (r = 0.31) to moderate (r = 0.42) between the three study sites. Categorizing BHI SDS and DXA BMD Z-scores on a 0-5 scale yielded a weak agreement between the two for both TBLH and LS, with w-kappa of 0.2, increasing to 0.3 when using quadratic weights. The agreement was notably higher for one of the three study sites as compared to the two others, particularly for spine assessment, yielding a moderate kappa value of 0.4 - 0.5. For cone-beam CT, based on a 1-3 scale, 59 out of 94 left TMJ's were scored as 1 and 31 as score 2 by the first observer vs. 87 and 7 by the second observer yielding a poor agreement (kappa 0.1).

CONCLUSIONS

Categorizing DXA LS and automated radiographic Z-scores on a 0-5 scale gave a weak to moderate agreement between the two methods, indicating that a hand radiograph might provide an adjuvant tool to DXA when assessing bone health children with JIA, given thorough calibration is performed.

Osteoporosis and Bone Fragility in Children: Diagnostic and Treatment Strategies

The incidence of osteoporosis in children is increasing because of the increased survival rate of children with chronic diseases and the increased use of bone-damaging drugs. As childhood bone fragility has several etiologies, its management requires a thorough evaluation of all potentially contributing pathogenetic mechanisms. This review focuses on the main causes of primary and secondary osteoporosis and on the benefits and limits of the different radiological methods currently used in clinical practice for the study of bone quality. The therapeutic and preventive strategies currently available and the most novel diagnostic and treatment strategies are also presented. Optimal management of underlying systemic conditions is key for the treatment of bone fragility in childhood. DXA still represents the gold standard for the radiologic evaluation of bone health in children, although other imaging techniques such as computed tomography and ultrasound evaluations, as well as REMS, are increasingly studied and used. Bisphosphonate therapy is the gold standard for pharmacological treatment in both primary and secondary pediatric osteoporosis. Evidence and experience are building up relative to the use of monoclonal antibodies such as denosumab in cases of poor response to bisphosphonates in specific conditions such as osteogenesis imperfecta, juvenile Paget's disease and in some cases of secondary osteoporosis. Lifestyle interventions including adequate nutrition with adequate calcium and vitamin D intake, as well as physical activity, are recommended for prevention.

Fat-free mass predictive equation using bioelectrical impedance and maturity offset in adolescent athletes: Development and cross-validation

OBJECTIVES

This is a cross-sectional study, aimed to develop and cross-validate a fat-free mass (FFM) predictive equation using single-frequency bioelectrical impedance (BIA), considering the predicted age at peak height velocity (PHV) as a variable. Additionally, the study aims to test the FFM-BIA obtained using a previous predictive equation that used skeletal maturity as a variable.

METHOD

The participants (n = 169 male adolescent athletes) were randomly divided into two groups: development of a new predictive equation (n = 113), and cross-validation (n = 56). The concordance test between the FFM values obtained by Koury et al. predictive equation and DXA data was determined (n = 169). Bioelectrical data was obtained using a single-frequency analyzer.

RESULTS

Among the models tested, the new predictive equation has resistance index (height2/resistance) and predictive age at PHV as variables and presented R2 = 0.918. The frequency of maturity status using skeletal maturity and PHV diagnosis was inadequate (Kappa = 0.4257; 95%CI = 0.298-0.553). Bland-Altman plots and concordance correlation coefficient showed substantial concordance between the FFM-DXA values (48.8 ± 11.2 kg) and the new predictive equation (CCC = 0.960). The results showed that the new equation performed better than the equation developed by Koury et al. (CCC = 0.901).

CONCLUSIONS

Our results show that it is feasible to predict FFM in male adolescent athletes using predictive age at PHV, with moderate concordance. The calculation of FFM using more economical and less complex variables is viable and should be further explored.

Per- and polyfluoroalkyl substances and bone mineral content in early adolescence: Modification by diet and physical activity

BACKGROUND

Per- and polyfluoroalkyl substance (PFAS) exposures may negatively impact bone mineral accrual, but little is known about potential mitigators of this relation. We assessed whether associations of PFAS and their mixture with bone mineral content (BMC) in adolescence were modified by diet and physical activity.

METHODS

We included 197 adolescents enrolled in a prospective pregnancy and birth cohort in Cincinnati, Ohio (2003-2006). At age 12 years, we collected serum for PFAS measurements and used dual-energy x-ray absorptiometry to measure BMC. We calculated dietary calcium intake and Health Eating Index (HEI) scores from repeated 24-h dietary recalls, physical activity scores using the Physical Activity Questionnaire for Older Children (PAQ-C), and average moderate to vigorous physical activity (MVPA) based on accelerometry. We estimated covariate-adjusted differences in BMC z-scores per interquartile range (IQR) increase of individual PFAS concentrations using linear regression and per simultaneous IQR increase in all four PFAS using g-computation. We evaluated effect measure modification (EMM) using interaction terms between each modifier and PFAS.

RESULTS

Higher serum perfluorooctanoic acid, perfluorooctanesulfonic acid, and perfluorononanoic acid concentrations and the PFAS mixture were associated with lower BMC z-scores. An IQR increase in all PFAS was associated with a 0.27 (-0.54, 0.01) lower distal radius BMC z-score. Associations with lower BMC were generally stronger among adolescents classified as < median for calcium intake, HEI scores, or MVPA compared to those ≥ median. The difference in distal radius BMC z-score per IQR increase in all PFAS was -0.38 (-0.72, -0.04) for those with

CONCLUSION

Healthy, calcium-rich diets and higher intensity physical activity may mitigate the adverse impact of PFAS on adolescent bone health.

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Key Words

• Adolescent health
• Bone mineral content
• Calcium
• Diet
• Perfluoroalkyl substances
• Physical activity

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MESH Headings

• Humans
• Female
• Fluorocarbons/blood
• Male
• Bone Density/drug effects
• Child
• Adolescent
• Diet
• Environmental Pollutants/blood
• Prospective Studies
• Ohio
• Alkanesulfonic Acids/blood
• Exercise
• Motor Activity/drug effects

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Grants

• R01 ES030078 NIEHS NIH HHS
• R01 ES033252 NIEHS NIH HHS
• R01 ES027224 NIEHS NIH HHS
• L40 ES032257 NIEHS NIH HHS
• P01 ES011261 NIEHS NIH HHS
• R01 ES032836 NIEHS NIH HHS
• R01 ES028277 NIEHS NIH HHS
• T32 ES007141 NIEHS NIH HHS
• R01 ES025214 NIEHS NIH HHS
• R01 ES020349 NIEHS NIH HHS

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Affiliation(s)

Jessie P Buckley Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
Junyi Zhou Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, USA
Katherine M Marquess Department of Environmental Health and Engineering, Johns Hopkins Bloomberg School of Public Health, Baltimore, USA
Bruce P Lanphear Faculty of Health Sciences, Simon Fraser University, Vancouver, Canada
Kim M Cecil Department of Radiology, Cincinnati Children's Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnati, USA; Department of Pediatrics, Cincinnati Children's Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnati, USA
Aimin Chen Department of Biostatistics, Epidemiology and Informatics, University of Pennsylvania Perelman School of Medicine, Philadelphia, USA
Clara G Sears Christina Lee Brown Envirome Institute, Department of Medicine, Division of Environmental Medicine, University of Louisville, KY, USA
Yingying Xu Department of Pediatrics, Cincinnati Children's Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnati, USA
Kimberly Yolton Department of Pediatrics, Cincinnati Children's Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnati, USA
Heidi J Kalkwarf Department of Pediatrics, Cincinnati Children's Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnati, USA
Joseph M Braun Department of Epidemiology, Brown University, Providence, USA
Jordan R Kuiper Department of Environmental and Occupational Health, The George Washington University Milken Institute School of Public Health, Washington, D.C., USA

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Prenatal and childhood exposure to bisphenols and bone mineral density in 7-year-old children from the Odense Child Cohort

BACKGROUND

Bisphenol A (BPA) is a well-known endocrine disrupter used in several consumer products. Restricted use of BPA has led to increased use of bisphenol F (BPF) and bisphenol S (BPS). While previous studies found no associations between prenatal BPA and BPF exposure and bone mineral density (BMD), two recent cohort studies found that prenatal BPS exposure was negatively associated with bone mineral density in the offspring.

AIM

To determine possible associations between maternal and child urinary bisphenol concentrations, BMD and bone mineral content (BMC) in 7-year-old healthy children.

METHODS

Pregnant women were recruited in 2010-2012 to participate in the Odense Child Cohort (OCC), Denmark. Maternal urine samples were collected in gestational week 28 and urinary BPA concentration was measured by isotope diluted LC-MS/MS. The children delivered a urine sample at age 7 years in which BPA, BPF and BPS were measured by an extended LS-MS/MS method based on the original method. At age 7 years DXA scans were performed and BMC and Z-score for BMD calculated. Associations between osmolality adjusted urinary maternal BPA and child BPA, BPF and BPS concentrations and BMC and BMD Z-score were examined by multiple linear regression analysis adjusted for potential confounders. Additionally, a combined effect of the bisphenols were evaluated by including the sum of child urinary BPA, BPF and BPS concentrations in the statistical analyses.

RESULTS

A total of 546 mothers and 453 children aged 7 years participated. BPA was detected in 84% and 96% of the maternal and child urine samples, respectively. We found no significant association between maternal urinary BPA concentration during pregnancy and BMC and BMD Z-score in 7-year-old children. In addition, no association between current bisphenol exposure in tertiles and bone density was found, interestingly, current BPA and summed bisphenol exposure in the highest 10% was associated with lower BMD Z-score at age 7-years, statistically significant for boys.

CONCLUSION

In these low exposed children we found no association between prenatal or current bisphenol exposure in tertiles and BMD in healthy children, however, the highest 10% exposed children had lower BMD, significant for boys, suggesting a negative impact with high bisphenol exposure. The short half-lives of bisphenols and the cross-sectional nature of the child exposure prompt more longitudinal studies to further clarify this topic.

Muscle-bone cross-talk through the FNIP1-TFEB-IGF2 axis is associated with bone metabolism in human and mouse

Clinical evidence indicates a close association between muscle dysfunction and bone loss; however, the underlying mechanisms remain unclear. Here, we report that muscle dysfunction-related bone loss in humans with limb-girdle muscular dystrophy is associated with decreased expression of folliculin-interacting protein 1 (FNIP1) in muscle tissue. Supporting this finding, murine gain- and loss-of-function genetic models demonstrated that muscle-specific ablation of FNIP1 caused decreased bone mass, increased osteoclastic activity, and mechanical impairment that could be rescued by myofiber-specific expression of FNIP1. Myofiber-specific FNIP1 deficiency stimulated expression of nuclear translocation of transcription factor EB, thereby activating transcription of insulin-like growth factor 2 (Igf2) at a conserved promoter-binding site and subsequent IGF2 secretion. Muscle-derived IGF2 stimulated osteoclastogenesis through IGF2 receptor signaling. AAV9-mediated overexpression of IGF2 was sufficient to decrease bone volume and impair bone mechanical properties in mice. Further, we found that serum IGF2 concentration was negatively correlated with bone health in humans in the context of osteoporosis. Our findings elucidate a muscle-bone cross-talk mechanism bridging the gap between muscle dysfunction and bone loss. This cross-talk represents a potential target to treat musculoskeletal diseases and osteoporosis.

Neuroendocrine disturbances in women with functional hypothalamic amenorrhea: an update and future directions

Functional hypothalamic amenorrhea (FHA) is one of the most common causes of both primary and secondary amenorrhea in women of reproductive age. It is characterized by chronic anovulation and the absence of menses that appear as a result of stressors such as eating disorders, excessive exercise, or psychological distress. FHA is presumed to be a functional disruption in the pulsatile secretion of hypothalamic gonadotropin-releasing hormone, which in turn impairs the release of gonadotropin. Hypoestrogenism is observed due to the absence of ovarian follicle recruitment. Numerous neurotransmitters have been identified which play an important role in the regulation of the hypothalamic-pituitary-ovarian axis and of which the impairment would contribute to developing FHA. In this review we summarize the most recent advances in the identification of contributing neuroendocrine disturbances and relevant contributors to the development of FHA.

Clinical, biochemical, and molecular insights into Cerebrotendinous Xanthomatosis: A nationwide study of 100 Turkish individuals

OBJECTIVE

Cerebrotendinous xanthomatosis (CTX) is an inherited metabolic disorder characterized by progressive neurologic and extraneurologic findings. The aim of this retrospective, descriptive study was to explore the time of presentation and diagnosis, and to expand the phenotype and genotype of CTX, based on a nationwide and comprehensive series of patients in Turkey.

METHODS

The demographic, clinical, biochemical and genotypic characteristics of the CTX patients were reviewed. Data on molecular analysis, age of onset and diagnosis, diagnostic delay, neurologic and extraneurologic symptomatology, results of plasma cholestanol levels, brain magnetic resonance imaging and electromyography at the time of diagnosis were reviewed.

RESULTS

100 confirmed CTX patients from 72 families were included. The mean age at diagnosis was 28.16 ± 14.28 years, and diagnostic delay was 18.39 ± 13.71 years. 36 patients were diagnosed in childhood. Frequency of intention tremor (p = 0.069), peripheral neuropathy (p = 0.234) and psychiatric manifestations (p = 0.396) did not differ between two groups, demonstrating the high rate in pediatric patients. Three adult patients showed a milder phenotype without neurologic involvement. Seven patients had normal plasma cholestanol levels despite neurological impairment. Sequencing of the CYP27A1 gene revealed 25 different variants, with a novel c.671_672del variant not previously described in literature.

CONCLUSION

Based on the observations of this Turkish CTX cohort, it is emphasized that the true prevalence of CTX is probably underestimated and that it has a wide spectrum of clinical phenotypes even without neurological impairment. In children, abnormal cerebellar findings, peripheral neuropathy and psychiatric findings associated with intellectual disability have been suggested as warning signs to avoid diagnostic delay. In cases of clinical suspicion, molecular analysis is recommended despite normal plasma cholestanol levels, as severe neurologic involvement may occur in CTX patients without elevated cholestanol levels.

Impaired bone mineral density and microarchitecture in female adolescents with IgE-mediated cow's milk allergy

This study compared the bone parameters of adolescents with persistent cow's milk allergy (CMA) with those of healthy adolescents. Adolescents with CMA had compromised bone parameters (lower bone mineral density, impaired trabecular microarchitecture, and lower bone strength). Partial exclusion diet was associated with better bone parameters than total exclusion diet.

BACKGROUND

Persistent immunoglobulin E (IgE)-mediated cow's milk allergy (CMA) may impair bone parameters and increase the risk of fractures. High-resolution peripheral quantitative computed tomography (HR-pQCT) is a novel methodology that not only assesses trabecular and cortical bone compartments and volumetric density measurements, but also evaluates bone microarchitecture and estimates biomechanical properties through finite element analysis (FEA). Both HR-pQCT and bone strength parameters derived from FEA have shown a strong correlation with fracture risk.

PURPOSE

To assess the bone density, microarchitecture, and bone strength of adolescents with persistent IgE-mediated CMA (IgE-CMA).

METHODS

This was an observational, cross-sectional study with female adolescents with persistent IgE-CMA and healthy control participants matched by female sex and sexual maturation. Bone parameters were assessed by areal bone mineral density (aBMD) through dual-energy X-ray absorptiometry (DXA), bone microarchitecture by HR-pQCT at the radius and tibia, and laboratory markers related to bone metabolism.

RESULTS

The median age of adolescents with persistent IgE-CMA (n = 26) was 13.0 years (interquartile range (IQR) 11.4-14.7) and of healthy control participants (n = 28) was 13.6 years (IQR 11.9-14.9). Adolescents with IgE-CMA ingested 27.4% less calcium (p = 0.012) and 28.8% less phosphorus (p = 0.009) than controls. Adolescents with IgE-CMA had lower bone mineral content (BMC) (38.83 g vs. 44.50 g) and aBMD (0.796 g/cm2 vs. 0.872 g/cm2) at lumbar spine, and lower BMC (1.11 kg vs. 1.27 kg) and aBMD (0.823 g/cm2 vs. 0.877 g/cm2) at total body less head (TBLH) (p < 0.05). However, Z-scores BMC and Z-scores aBMD at lumbar spine and TBLH, when adjusted for Z-score height/age, were not significantly different between the groups. Moreover, CMA adolescents had lower bone strength at the distal tibia (S 169 kN/mm vs. 194 kN/mm; F Load 8030 N vs. 9223 N) (p < 0.05). Pairing of groups by the presence of menarche showed compromised parameters at the tibia-lower total volumetric BMD (Tt.vBMD) (293.9 mg HA/cm3 vs. 325.9 mg HA/cm3) and trabecular vBMD (Tb.vBMD) (170.8 mg HA/cm3 vs. 192.2 mg HA/cm3), along with lower cortical thickness (Ct.th) (1.02 mm vs. 1.16 mm) and bone strength (S 174 kN vs. 210 kN; F Load 8301 N vs. 9950 N)-and at the radius (S 61 kN/mm vs. 71 kN/mm; F Load 2920 N vs. 3398 N) (p < 0.05) among adolescents with IgE-CMA. Adolescents with IgE-CMA on a total exclusion diet (n = 12) showed greater impairment of bone features than those on a partial exclusion diet (n = 14), with lower lumbar spine Z-score BMC (- 0.65 vs. 0.18; p = 0.013), lumbar spine trabecular bone score (TBS) (1.268 vs. 1.383; p = 0.005), Z-score TBS (0.03 vs. 1.14; p = 0.020), TBLH Z-score BMC (- 1.17 vs. - 0.35; p = 0.012), TBLH Z-score aBMD (- 1.13 vs. - 0.33; p = 0.027), Tt.vBMD at the tibia (259.0 mg HA/cm3 vs. 298.7 mg HA/cm3; p = 0.021), Ct.th at the tibia (0.77 mm vs. 1.04 mm; p = 0.015) and Ct.th at the radius (0.16 mm vs. 0.56 mm; p = 0.033).

CONCLUSION

Adolescents with persistent IgE-CMA had lower aBMD and compromised microarchitecture (impaired trabecular microarchitecture and lower bone strength). Adolescents on a partial exclusion diet had better bone parameters than those on a total exclusion diet.

GBA1 as a risk gene for osteoporosis in the specific populations and its role in the development of Gaucher disease

BACKGROUND

Osteoporosis and its primary complication, fragility fractures, contribute to substantial global morbidity and mortality. Gaucher disease (GD) is caused by glucocerebrosidase (GBA1) deficiency, leading to skeletal complications. This study aimed to investigate the impact of the GBA1 gene on osteoporosis progression in GD patients and the specific populations.

METHODS

We selected 8115 patients with osteoporosis (T-score ≤ - 2.5) and 55,942 healthy individuals (T-score > - 1) from a clinical database (N = 95,223). Monocytes from GD patients were evaluated in relation to endoplasmic reticulum (ER) stress, inflammasome activation, and osteoclastogenesis. An in vitro model of GD patient's cells treated with adeno-associated virus 9 (AAV9)-GBA1 to assess GBA1 enzyme activity, chitotriosidase activity, ER stress, and osteoclast differentiation. Longitudinal dual-energy X-ray absorptiometry (DXA) data tracking bone density in patients with Gaucher disease (GD) undergoing enzyme replacement therapy (ERT) over an extended period.

RESULTS

The GBA1 gene variant rs11264345 was significantly associated [P < 0.002, Odds Ratio (OR) = 1.06] with an increased risk of bone disease. Upregulation of Calnexin, NOD-, LRR- and pyrin domain-containing protein 3 (NLRP3) and Apoptosis-associated speck-like protein containing a C-terminal caspase recruitment domain (ASC) was positively associated with osteoclastogenesis in patients with GD. In vitro AAV9-GBA1 treatment of GD patient cells led to enhanced GBA1 enzyme activity, reduced chitotriosidase activity, diminished ER stress, and decreased osteoclast differentiation. Long-term bone density data suggests that initiating ERT earlier in GD leads to greater improvements in bone density.

CONCLUSIONS

Elevated ER stress and inflammasome activation are indicative of osteoporosis development, suggesting the need for clinical monitoring of patients with GD. Furthermore, disease-associated variant in the GBA1 gene may constitute a risk factor predisposing specific populations to osteoporosis.

Reference-Class Problems Are Real: Health-Adjusted Reference Classes and Low Bone Mineral Density

Elselijn Kingma argues that Christopher Boorse's biostatistical theory (the BST) does not show how the reference classes it uses are objective and naturalistic. Recently, philosophers of medicine have attempted to rebut Kingma's concerns. I argue that these rebuttals are theoretically unconvincing, and that there are clear examples of physicians adjusting their reference classes according to their prior knowledge of health and disease. I focus on the use of age-adjusted reference classes to diagnose low bone mineral density in children. In addition to using the BST's age, sex, and species, physicians also choose to use other factors to define reference classes, such as pubertal status, bone age, body size, and muscle mass. I show that physicians calibrate the reference classes they use according to their prior knowledge of health and disease. Reference classes are also chosen for pragmatic reasons, such as to predict fragility fractures.

Exposure to perfluoroalkyl substances and longitudinal changes in bone mineral density in adolescents and young adults: A multi-cohort study

BACKGROUND

Per- and polyfluoroalkyl substances (PFAS) may impair bone development in adolescence, which impacts life-long bone health. No previous studies have examined prospective associations of individual PFAS and their mixture with bone mineral density (BMD) changes in Hispanic young persons, a population at high risk of osteoporosis in adulthood.

OBJECTIVES

To examine associations of individual PFAS and PFAS mixtures with longitudinal changes in BMD in an adolescent Hispanic cohort and examine generalizability of findings in a mixed-ethnicity young adult cohort (58.4% Hispanic).

METHODS

Overweight/obese adolescents from the Study of Latino Adolescents at Risk of Type 2 Diabetes (SOLAR; n = 304; mean follow-up = 1.4 years) and young adults from the Southern California Children's Health Study (CHS; n = 137; mean follow-up = 4.1 years) were included in this study. Plasma PFAS were measured at baseline and dual x-ray absorptiometry scans were performed at baseline and follow-up to measure BMD. We estimated longitudinal associations between BMD and five PFAS via separate covariate-adjusted linear mixed effects models, and between BMD and the PFAS mixture via quantile g-computation.

RESULTS

In SOLAR adolescents, baseline plasma perfluorooctanesulfonic acid (PFOS) was associated with longitudinal changes in BMD. Each doubling of PFOS was associated with an average -0.003 g/cm2 difference in change in trunk BMD per year over follow-up (95% CI: -0.005, -0.0002). Associations with PFOS persisted in CHS young adults, where each doubling of plasma PFOS was associated with an average -0.032 g/cm2 difference in total BMD at baseline (95% CI -0.062, -0.003), though longitudinal associations were non-significant. We did not find associations of other PFAS with BMD; associations of the PFAS mixture with BMD outcomes were primarily negative though non-significant.

DISCUSSION

PFOS exposure was associated with lower BMD in adolescence and young adulthood, important periods for bone development, which may have implications on future bone health and risk of osteoporosis in adulthood.

Assessment of Biochemical Bone Turnover Markers in Polish Healthy Children and Adolescents

BACKGROUND

Assessing bone turnover in paediatric populations is crucial for understanding the physiological changes occurring during skeletal development and identifying potential abnormalities. The objective of this study was to assess osteocalcin (OC), bone alkaline phosphatase (BALP), and C-terminal telopeptide of type I collagen (CTX-I) levels reflecting bone formation and resorption for age and sex in Polish healthy children and adolescents.

MATERIALS AND METHODS

A total of 355 healthy normal-weight children and adolescents (46.5% girls) aged 1-18 years old were recruited. Total body less head (TBLH) and spine L1-L4 were used in children to assess bone mineral density (BMD) by dual-energy X-ray absorptiometry (DXA). Bone marker concentrations were determined by immunoenzymatic methods.

RESULTS

Bone marker levels in girls and boys started with higher values in the first year of life and subsequently decreased until reaching a nadir during the prepubertal period. The pubertal peak values of bone markers were reached at 11-13 years old in boys and at 9-11 years old in girls. After puberty, the adolescents showed a gradual decline in bone marker concentrations to the values observed in adults. We found positive correlations between OC level and TBLH-BMD (r = 0.329, p = 0.002), TBLH-BMD Z-score (r = 0.245, p = 0.023), and L1-L4 BMD (r = 0.280, p = 0.009) in the prepubertal group.

CONCLUSIONS

We showed serum levels of bone turnover markers-BALP, OC, and CTX-I-in relation to age and sex in healthy Polish children and adolescents. The age intervals of these markers for girls and boys aged 1-18 years old may be clinically useful in the assessment of bone metabolism in individuals with skeletal disorders.

ESPEN-ESPGHAN-ECFS guideline on nutrition care for cystic fibrosis

BACKGROUND

Nutritional status is paramount in Cystic Fibrosis (CF) and is directly correlated with morbidity and mortality. The first ESPEN-ESPGHAN-ECFS guidelines on nutrition care for infants, children, and adults with CF were published in 2016. An update to these guidelines is presented.

METHODS

The study was developed by an international multidisciplinary working group in accordance with officially accepted standards. Literature since 2016 was reviewed, PICO questions were discussed and the GRADE system was utilized. Statements were discussed and submitted for on-line voting by the Working Group and by all ESPEN members.

RESULTS

The Working Group updated the nutritional guidelines including assessment and management at all ages. Supplementation of vitamins and pancreatic enzymes remains largely the same. There are expanded chapters on pregnancy, CF-related liver disease, and CF-related diabetes, bone disease, nutritional and mineral supplements, and probiotics. There are new chapters on nutrition with highly effective modulator therapies and nutrition after organ transplantation.

Research hotspots for pediatric fractures from 2017 to 2022: A bibliometric and visual analysis via Citespace

Objective

This review provides guidance and ideas for researchers through a comprehensive and comparative analysis of the present state, trends, and hotspots in the pediatric fracture literature over the past 6 years.

Methods

We used Citespace 6.1.R6 software to explore the country/region distribution, institutions, journals, keyword analysis, and co-cited references of the literature from Web of Science core database.

Results

There are 6472 pieces of pediatric fracture-related literature, including 2962 from 2017 to 2019 and 3510 from 2020 to 2022. The country with the most papers is the United States, and US institutions and journals also have a pivotal position in this field. Research hotspots for pediatric fractures in 2017-2019: The topic with the most attention is bone mineral density leading to related bone diseases. Treatment for pediatric fractures, including supracondylar humeral fractures, Monteggia fractures, forearm fractures, knee fractures, and ankle fractures in children, is another topic of greater interest. Brain injuries and dental injuries in children due to abuse and trauma are also concerning issues. Research hotspots for pediatric fractures in 2020-2022: comparison with 2017-2019 revealed a relative decrease regarding ankle-related epiphyseal injuries, but there is a higher focus on the epidemiology of fractures in children, risk factors, and reasons for childhood trauma. We have confirmed through literature co-citations that the literature of high interest is also in these aspects.

Conclusion

Researchers and clinicians can quickly learn about topics of interest through authoritative journals and highly cited literature and rapidly master the current status and frontiers of the field through study, providing ideas for future work.

Bone Mineral Density and Vitamin D Status in Patients with Autoimmune Polyglandular Syndromes: A Single Tertiary Care Center Experience

Immunological abnormalities, the resulting endocrinopathies, and their treatments may impact bone health and 25-hydroxyvitamin D (25-OHD) in patients with autoimmune polyglandular syndromes (APS). Several etiologies contribute to increased risk for low bone mineral density (BMD), including vitamin D deficiency. This study evaluated the vitamin D level and BMD of patients with APS. We performed a cross-sectional study on 44 patients with APS and 55 age and gender-matched control subjects. Among patients with APS, 14 were classified as APS-2 [Addison's disease (AD)+autoimmune thyroid disease (ATD) and/or type 1 diabetes(T1D)]. In contrast, the other 30 were APS-3 (ATD+T1D+other autoimmune diseases). Serum samples were analyzed for vitamin D levels. The lumbar spine and femoral neck BMD were measured by dual X-ray absorptiometry. Z-scores were obtained by comparison with age- and gender-matched average values (both patients and controls). The accepted normal levels were Z-score>-1 and 25-OHD>30 ng/ml. Patients with APS showed 25-OHD levels and BMD significantly lower than healthy controls (p<0.001 and p<0.05, respectively). The highest prevalence of abnormal BMD was observed in the APS-2 subgroup (13 out of 14 patients, 92.6%). Identifying and treating vitamin D deficiency and low BMD is critical in APS patients. The fact that the significant endocrine component of APS-2 is AD, and these patients receive chronic long-term glucocorticoid therapy can be shown as the reason for this result. However, more extensive prospective controlled studies are needed to confirm these findings.

The Relationship between Bone Health Parameters, Vitamin D and Iron Status, and Dietary Calcium Intake in Young Males

Vitamin D, calcium, and iron are micronutrients crucial for bone health. However, their effect has been studied primarily in the cortical bone, with vitamin D status being assessed mainly from the total 25(OH)D serum fraction. The study aimed to investigate the impact of vitamin D (total and free fraction) and iron status (i.e., serum ferritin or soluble transferrin receptor) and calcium intake (ADOS-Ca questionnaire) on lumbar cortical and trabecular bone. In a cohort of 113 male subjects (76 athletes, 37 non-athletes) aged 15-19, the lumbar spine status (Z-score, bone mineral apparent density (BMAD), and trabecular bone score (TBS)) was determined using dual-energy X-ray absorptiometry (DXA). Relationships between the examined micronutrients and bone health parameters were observed only in athletes. Free 25(OH)D was significantly (p < 0.001) correlated with Z-score and BMAD, while total 25(OH)D (p < 0.001) and iron status (ferritin, Fe stores; p < 0.01) correlated solely with BMAD. Free 25(OH)D and ferritin concentrations were the best determinants of bone status (R2 = 0.330; p < 0.001) and explained 25% and 7% of the BMAD variance, respectively. No relationships were found between the micronutrients and TBS. The results confirmed the positive influence of vitamin D and iron on cortical, but not trabecular, bone status solely in physically active subjects. In athletes, free 25(OH)D seems to be a superior indicator of bone health to a total 25(OH)D fraction.

Effects of Hormone Replacement Therapy on Bone Mineral Density in Korean Adults With Turner Syndrome

BACKGROUND

Turner syndrome (TS) is a common chromosomal abnormality, which is caused by loss of all or part of one X chromosome. Hormone replacement therapy in TS is important in terms of puberty, growth and prevention of osteoporosis however, such a study has never been conducted in Korea. Therefore, the purpose of our study was to determine relationship between the starting age, duration of estrogen replacement therapy (ERT) in TS and develop a hormone replacement protocol suitable for the situation in Korea.

METHODS

This is retrospective study analyzed the medical records in TS patients treated at the Severance hospital, Yonsei University College of Medicine, Seoul, Korea from 1997 to 2019. Total of 188 subjects who had received a bone density test at least once were included in the study. Korean National Health and Nutrition Examination Survey (KNHANES) was used for achieving bone mineral density (BMD) of normal control group. Student's t-test, Mann-Whitney U test, ANOVA and correlation analysis were performed using SPSS 18.0.

RESULTS

Each BMD measurement was significantly lower in women with TS than in healthy Korean women. Early start and longer duration of ERT is associated with higher lumbar spine BMD but not femur neck BMD. Femur neck BMD, but not lumbar spine BMD was significantly higher in women with mosaicism than 45XO group.

CONCLUSION

Early onset and appropriate duration of hormone replacement therapy is important for increasing bone mineral density in patients with Turner syndrome. Also, ERT affects differently to TS patients according to mosaicism.

Which indices of cardiorespiratory fitness are more strongly associated with brain health in children with overweight/obesity?

PURPOSE

To compare the strength of associations between different indices of cardiorespiratory fitness (CRF) and brain health outcomes in children with overweight/obesity.

METHODS

Participants were 100 children aged 8-11 years. CRF was assessed using treadmill exercise test (peak oxygen uptake [V̇O2peak ], treadmill time, and V̇O2 at ventilatory threshold) and 20-metre shuttle run test (20mSRT, laps, running speed, estimated V̇O2peak using the equations by Léger et al., Mahar et al., and Matsuzaka et al.). Intelligence, executive functions, and academic performance were assessed using validated methods. Total gray matter and hippocampal volumes were assessed using structural MRI.

RESULTS

V̇O2peak /body mass (β = 0.18, 95% CI = 0.01-0.35) and treadmill time (β = 0.18-0.21, 95% CI = 0.01-0.39) were positively associated with gray matter volume. 20mSRT laps were positively associated with executive functions (β = 0.255, 95% CI = 0.089-0.421) and academic performance (β = 0.199-0.255, 95% CI = 0.006-0.421), and the running speed was positively associated with executive functions (β = 0.203, 95% CI = 0.039-0.367). Estimated V̇O2peak/Léger et al. was positively associated with intelligence, executive functions, academic performance, and gray matter volume (β = 0.205-0.282, 95% CI = 0.013-0.500). Estimated V̇O2peak/Mahar et al. and V̇O2peak/Matsuzaka et al. (speed) were positively associated with executive functions (β = 0.204-0.256, 95% CI = 0.031-0.436).

CONCLUSION

Although V̇O2peak is considered the gold standard indicator of CRF in children, peak performance (laps or running speed) and estimated V̇O2peak/Léger et al. derived from 20mSRT had stronger and more consistent associations with brain health outcomes than other indices of CRF in children with overweight/obesity.

Dual x-ray absorptiometry monitoring in pediatric short bowel syndrome: an integrative review

OBJECTIVE

To analyze the bone health of pediatric patients with short bowel syndrome intestinal failure (SBS-IF).

DATA SOURCE

An integrative literature review was performed using the data published in the MEDLINE-PubMed and Scientific Electronic Library Online (SciELO) databases between January 2010 and April 2021, and through a manual search of the reference lists of relevant studies. Studies were included if they assessed bone mineral density by the Dual X-Ray Absorptiometry (DXA) technique, incorporated pediatric patients (up to 20 years of age) with SBS under parenteral nutrition (PN) and were written in English. Eleven primary sources met the inclusion criteria for this study.

DATA SYNTHESIS

Pediatric patients with SBS-IF under long-term parenteral nutrition experienced frequent changes in bone metabolism, leading to osteoporotic fractures and growth failure. These patients have deficiencies in multiple nutrients, such as calcium, magnesium, phosphorus, and vitamin D. Consequently, there are variations in the secretion and regulation of the parathyroid hormone. In addition, the pharmacotechnical limitations related to calcium and phosphorus in the PN solution, use of glucocorticoids, and difficulty performing physical activity are risk factors for the development of metabolic bone disease in pediatric patients with SBS-IF.

CONCLUSIONS

Low bone mineral density was associated with a high risk of developing osteoporosis, fractures, and growth deficiency in pediatric patients with SBS-IF on PN therapy in the long term.

Evaluation of bone mineral density in adolescent idiopathic scoliosis using a three-dimensional finite element model: a retrospective study

BACKGROUND

Adolescent idiopathic scoliosis (AIS) is often accompanied by osteopenia and osteoporosis, which can cause serious complications. The aim of this study was to determine the specific bone mineral density (BMD) of each vertebral body in patients with AIS using biomechanical finite element modeling based on three-dimensional (3D) reconstruction.

METHODS

This retrospective study involved 56 patients with AIS. Computed tomography (CT) and radiography were performed. Spinal vertebrae were segmented from the spinal CT images of patients with AIS to reconstruct 3D vertebral models. The vertebral models were meshed into tetrahedral finite elements to assess the BMD.

RESULTS

The mean main curve Cobb angle was 88.6 ± 36.7°, and the mean kyphosis angle was 36.8 ± 31.5°. The mean BMD of the global spine was 0.83 ± 0.15 g/cm2. The highest BMD was measured on the concave side of the apex (0.98 ± 0.16 g/cm2). Apical vertebral BMD was negatively correlated with age and height (r = - 0.490, p = 0.009 and r =  - 0.478, p = 0.043, respectively). There were no significant differences in BMD values between the concave and convex sides (p > 0.05).

CONCLUSIONS

The 3D finite element modeling of BMD in patients with AIS is a reliable and accurate BMD measurement method. Using this method, the overall BMD of patients with AIS was shown to gradually decrease from the top to the bottom of the spine. Our findings provide valuable insights for surgical planning, choice of screw trajectories, and additional biomechanical analyzes using finite element models in the context of scoliosis.

Assessment of Bone Health Using Dual-Energy X-Ray Absorptiometry (DEXA) And Its Association with Dietary Intakes, Serum Vitamin D Levels, and Anthropometric Measures in Healthy Urban Preschool Children

OBJECTIVES

To generate reference data for bone mineral content (BMC) and bone mineral density (BMD) measures among apparently healthy children aged 4-5 y and to study the relationship of BMC and BMD with age, sex, anthropometric measures, dietary intakes, and serum vitamin D levels.

METHODS

This cross-sectional study was conducted among 219 urban preschool children, aged 4.0-5.11 y. Bone health (BMC and BMD) was measured using dual energy X-ray absorptiometry (DEXA). Anthropometric parameters were measured using standard methodology. The 24-h dietary recall method was used to assess the dietary intake of the children. Serum vitamin D levels were assessed using the ELISA kit method. Percentiles for BMC and BMD for each age and sex were constructed using the lambda-mu-sigma (LMS) method.

RESULTS

The mean BMD and BMC among children was 0.75 ± 0.04 g/cm2 and 544.9 ± 87.6 g, respectively, and were significantly different by age and sex category. The BMC and BMD values of boys and girls increased with age, with boys having significantly higher values. A significant positive correlation was observed for BMC and BMD with anthropometric measures and dietary intake of calcium, phosphorous, protein, zinc, and B vitamins.

CONCLUSION

This study developed smoothed percentile curves for BMC and BMD in preschool children, which could be used as reference values for children from India.

Bone Fracture in Rett Syndrome: Mechanisms and Prevention Strategies

The present study aimed to evaluate the burden and management of fragility fractures in subjects with Rett syndrome. We searched all relevant medical literature from 1 January 1986 to 30 June 2023 for studies under the search term "Rett syndrome and fracture". The fracture frequency ranges from a minimum of 13.9% to a maximum of 36.1%. The majority of such fractures occur in lower limb bones and are associated with low bone mineral density. Anticonvulsant use, joint contractures, immobilization, low physical activity, poor nutrition, the genotype, and lower calcium and vitamin D intakes all significantly impair skeletal maturation and bone mass accrual in Rett syndrome patients, making them more susceptible to fragility fractures. This review summarizes the knowledge on risk factors for fragility fracture in patients with Rett syndrome and suggests a possible diagnostic and therapeutic care pathway for improving low bone mineral density and reducing the risk of fragility fractures. The optimization of physical activity, along with adequate nutrition and the intake of calcium and vitamin D supplements, should be recommended. In addition, subjects with Rett syndrome and a history of fracture should consider using bisphosphonates.

Trabecular Bone Score in Assessing Bone Mineralization Status in Children with End- Stage Renal Disease: A Promising Tool

Areal-bone mineral density (aBMD) of lumbar-spine dual energy X-ray absorptiometry (DXA) scan is the most frequently used tool in evaluating BMD in pediatric patients, however its size dependency have significant impact on measurements accuracy in children with chronic kidney disease (CKD). This study aimed to evaluate the usefulness of trabecular bone score (TBS) computed during lumbar-spine DXA scan in assessing bone status in children on maintenance hemodialysis (HD). Ninety-three children on HD (aged 9-18 years) were subjected to lumbar-spine DXA-scan to obtain aBMD (g/cm2) and TBS.Z-scores of aBMD for chronological-age (aBMDZ-CA), height-age (aBMDZ-HA), and TBSZ-score were calculated using mean and SD values of 442 healthy controls. aBMD and TBS were significantly lower in short-for-age and normal height-for-age patients compared to the corresponding values of controls (p < 0.05 for all). Degraded vertebral microarchitecture (TBSZ-score < -2) was detected in 48% and 44% of male and female patients respectively. There were no significant differences in median TBSZ-score between short-for-age and normal height-for-age HD patients in male (p = 0.425) and in female (p = 0.316) patients. TBSZ-score correlated significantly with aBMDZ-CA (r = 0.234; p = 0.024) but not with aBMDZ-HA (r = 0.077; p = 0.462). Patients with history of fractures (5 patients only) had significantly lower TBS scores compared to those without fracture history (p = 0.016).

CONCLUSION

TBS is significantly reduced in children on maintenance HD and is associated with increased fracture incidence. TBS has shown to be a promising tool in assessing bone quality (trabecular microarchitecture) in children with CKD being not size-dependent as is a-BMD, for further evaluation of its potential role in therapeutic and follow-up decisions.

WHAT IS KNOWN

• In children with CKD, bone demineralization starts as early as CKD stage 2, so assessment of bone health is mandatory for follow up and therapeutic decisions. • aBMD of lumbar-spine DXA scan is the most used tool in evaluating BMD in pediatric patients, however its size dependency have significant impact on measurements made in children with CKD.

WHAT IS NEW

• TBS is significantly reduced in children on maintenance HD and associated with increased fracture incidence. • TBS has shown to be a promising tool in assessing bone quality (trabecular microarchitecture) in children with CKD being not size-dependent as is a-BMD.

Prenatal and early postnatal exposure to perfluoroalkyl substances and bone mineral content and density in the Odense Child Cohort

INTRODUCTION

Exposure to perfluoroalkyl substances (PFAS) has been associated with lower bone mineral density (BMD) in animal and human studies, but prospective data from children are limited.

OBJECTIVES

To determine associations between prenatal and early postnatal PFAS exposure and BMD at age 7 years.

METHODS

In the Odense Child Cohort, Denmark, pregnant women were recruited in 2010-2012, and their children were invited for subsequent health examinations. At 12 weeks of gestation the pregnant women delivered a serum sample, and at age 18 months serum was obtained from the child to measure perfluorooctane sulfonic acid(PFOS), perfluorooctanoic acid (PFOA), perfluorohexane sulfonic acid (PFHxS), perfluorononanoic acid (PFNA) and perfluorodecanoic acid (PFDA) by LC-MS/MS. At age 7 years DXA scans were performed to measure bone mineral content (BMC) and BMD Z-score. PFAS in pregnancy (n = 881) and/or at age 18 months (n = 668) were regressed against DXA measurements, adjusted for maternal education, child height Z-score, sex (for BMC) and for postnatal exposure, additionally duration of total breastfeeding. We additionally performed structural equation models determining combined effects of pre-and postnatal PFAS exposures.

RESULTS

Higher prenatal and early postnatal serum concentrations of all measured PFAS were associated with lower BMC and BMD Z-scores at age 7 years, all estimates were negative although not all significant. For each doubling of 18-month exposure to PFNA or PFOS, BMD Z-scores were lowered by -0.10 (95 % CI -0.19;-0.00) and -0.08 (-0.17;-0.00), respectively after adjustment. Pre- and postnatal PFAS were correlated, but structural equation models suggested that associations with BMD were stronger for 18-month than prenatal PFAS exposure.

DISCUSSION

Bone density is established in childhood, and a reduction in BMD during early childhood may have long-term implication for peak bone mass and lifelong bone health. Future studies of the impact of PFAS exposure on fracture incidence will help elucidate the clinical relevance.

Hand grip strength, vitamin D status, and diets as predictors of bone health in 6-12 years old school children

BACKGROUND

Vitamin D and calcium-rich foods, exposure to sunlight, and physical activities (PA) play a pivotal role in promoting the production of sufficient vitamin D and improving grip strength needed for better bone health among school children.

PURPOSE

This study aimed to determine the effects of hand grip muscle strength (HGS), vitamin D in addition to diets, and PA on bone health status among 6-12 years old schoolchildren.

METHODS

This study was based on a cross-sectional observational design, which was descriptive in nature. A diverse sample of 560 elementary school children aged 6-12 years old were invited to participate in this descriptive cross-sectional study. The Dual-Energy X-Ray Absorptiometry (DXA), QUS technique, and ACTi graph GT1M accelerometer were used respectively as a valid tools to identify BMD, BMC, and other parameters of bone health like c-BUA values and bone stiffness (SI), and physical activity (PA) of all individuals participated in this study. In addition, a hydraulic dynamometer was used to measure hand grip strength among the participants. Moreover, an immunoassay technique was used to measure the serum levels of vitamin 25(OH)D level, and bone metabolism markers; NTX, DPD, Ca, and sBAP in all participants. Bone loss (osteoporosis) was cross-sectionally predicted in 19.64% of the total population, most of whom were girls (14.3% vs. 5.4% for boys; P = 0.01). Compared to boys, the incidence of osteoporosis was higher and significantly correlated in girls with lower HGS, deficient vitamin D, inadequate vitamin D and Ca intake, greater adiposity, poor PA, and lower sun exposure. Also, in girls, lower vitamin 25(OH)D levels, and poor HGS were shown to be significantly associated with lower values of BMD, BMC, SI, and higher values of bone resorption markers; NTX, DPD, and sBAP and lower serum Ca than do in boys. The findings suggested that deficient vitamin D, lower HGS, adiposity, PA, and sun exposure as related risk factors to the pravelence of bone loss among school children, particularly in girls. In addition, these parameters might be considered diagnostic non-invasive predictors of bone health for clinical use in epidemiological contexts; however, more studies are required.

Reference ranges for body composition indices by dual energy X-ray absorptiometry from the Bone Mineral Density in Childhood Study Cohort

BACKGROUND

Body composition assessment aids evaluation of energy stores and the impact of diseases and interventions on child growth. Current United States pediatric reference ranges from the National Health and Nutrition Examination Survey (NHANES) include 20% of children with obesity, body mass index of ≥95th percentile.

OBJECTIVES

This study aimed to develop dual energy X-ray absorptiometry (DXA) based reference ranges in a diverse cohort with low-obesity prevalence from the Bone Mineral Density in Childhood Study (BMDCS).

METHODS

This is a secondary analysis of a longitudinal, prospective, observational cohort. Healthy children (height and BMI within 3rd to 97th percentiles, ages 5-19 y at enrollment), from 5 United States centers were measured annually for ≤7 visits. Whole body scans were acquired using Hologic scanners. A subsample underwent repeat measurements to determine precision. We generated reference ranges for appendicular and total lean soft tissue mass index (LSTM Index), fat mass index (FMI), and other body composition measures. Resulting curves were compared to NHANES and across subgroups. Sex and age-specific equations were developed to adjust body composition Z-scores for height Z score.

RESULTS

We obtained 9846 scans of 2011 participants (51% female, 22% Black, 17% Hispanic, 48% White, 7% Asian/Pacific Islander, and 6% with obesity). Precision (percent coefficient of variation) ranged from 0.7% to 1.96%. Median and-2 standard deviation curves for BMDCS and NHANES were similar, but NHANES +2 standard deviation LSTM Index and FMI curves were distinctly greater than the respective BMDCS curves. Subgroup differences were more extreme for appendicular LSTM Index-Z (mean ± SD: Asian -0.52 ± 0.93 compared with Black 0.77 ± 0.87) than for FMI-Z (Hispanic 0.29 ± 0.98 compared with Black -0.14 ± 1.1) and were smaller for Z-scores adjusted for height Z-score.

CONCLUSIONS

These reference ranges add to sparse normative data regarding body composition in children and adolescents and are based on a cohort with an obesity prevalence similar to current BMI charts. Awareness of subgroup differences aids in interpreting results.

Bone Density, Geometry, Structure and Strength Estimates in Adolescent and Young Adult Women with Atypical Anorexia Nervosa versus Typical Anorexia Nervosa and Normal-Weight Healthy Controls

Our objective was to characterize bone outcomes in adolescent and young adult women with atypical anorexia nervosa (AAN) compared to typical AN and normal-weight healthy controls (HC) based on DSM-5 criteria. Four hundred thirty-two participants (141 AN, 131 AAN and 160 HC), ages 12-21 years, underwent dual-energy X-ray absorptiometry for areal BMD, and a subset had high-resolution peripheral quantitative CT assessment of the distal radius and tibia for volumetric BMD (vBMD), bone geometry and microarchitecture, and microfinite element analysis for estimated strength. The groups did not differ for age, pubertal stage, menarcheal age or physical activity. BMI and bone outcomes overall were intermediate in AAN compared with AN and HC. This applied to spine, total hip and femoral neck BMD measures and many distal tibial measures. However, the mean whole-body less head BMD Z-score did not differ between AAN and AN, and it was lower in both vs. HC. Similarly, many distal radius measures did not differ between AAN vs. AN or HC but were lower in AN than HC. Lower BMI, lean mass and bone age, older menarcheal age and longer illness duration correlated with greater impairment of bone outcomes. These data indicate that individuals with AAN overall have bone outcomes that are intermediate between AN and HC.

Inverted U-Shaped Relationship between Obesity Parameters and Bone Mineral Density in Korean Adolescents

As the association between obesity and bone health remains controversial in children and adolescents, we investigate the effects of obesity parameters on bone mineral density (BMD) in 2060 Korean adolescents who participated in the 2008-2011 Korea National Health and Nutrition Examination Survey (KNHANES). Multiple regression analysis and analysis of covariance (ANCOVA) were conducted to examine both the linear and non-linear associations between total-body-less-head (TBLH) BMD and four obesity parameters: body mass index, waist circumference, waist-to-height ratio, and total-body fat mass (FM). In a multiple linear regression analysis adjusted for age, menarcheal status (in females only), and total-body lean mass, there was no significant linear association between obesity parameters and TBLH BMD, except for total-body FM in males. However, upon adding a second-order polynomial term for each obesity parameter, a significant quadratic relationship between all obesity parameters and TBLH BMD was observed, with the corresponding quadratic term being negative. The results of ANCOVA also revealed an inverted U-shaped relationship between each obesity parameter and TBLH BMD. Our findings suggest the existence of an optimal range of obesity parameters for developing or maintaining optimal bone health in Korean Adolescents. Deviation from this range, in either direction (being underweight or having obesity), may compromise bone health.

Association of trabecular bone score and bone mineral apparent density with the severity of bone fragility in children and adolescents with osteogenesis imperfecta: A cross-sectional study

Osteogenesis imperfecta (OI) is a hereditary skeletal disease characterized by bone fragility. Areal bone mineral density (BMD), evaluated by dual-energy X-ray absorptiometry (DXA), is used to assess bone brittleness. The height-adjusted BMD Z-score (BMDHAZ) is calculated in children and adolescents with OI to reduce the confounding factor of short stature. However, even with the BMDHAZ, severity evaluation in children and adolescents with OI is challenging because certain abnormalities in bone quality cannot be accurately assessed by BMD analysis. The trabecular bone scores (TBS) and bone mineral apparent density (BMAD), which represent the structural integrity of bone and bone-size-associated BMD, respectively, are associated with fracture risk. Recently, age- and sex-specific reference ranges have been reported, enabling the calculation of Z-scores for children. To evaluate which density measurements show the highest correlation with fracture risk, we analyzed the associations between the Z-scores of TBS, BMAD, and BMDHAZ, fracture rate, and genetic variants. We retrospectively reviewed 42 participants with OI aged 5 to 20 years who underwent DXA. COL1A1/2 pathogenic variants were detected in 41 of the 42 participants. In participants with nonsense and frameshift variants (n = 17) resulting in haploinsufficiency and mild phenotype, the TBS Z-score was negatively correlated with fracture rate (FR) (r = -0.50, p = 0.042). In participants with glycine substitution (n = 9) causing the severe phenotype, the BMAD Z-scores were negatively correlated with FR (r = -0.74, p = 0.022). No correlation between the BMDHAZ and FR was observed in both groups. These findings suggest that the TBS and BMAD are useful in assessing children and adolescents with OI with specific genetic variants.

A Three-Year Follow-Up of Bone Density Among Thai Adolescents With Perinatally Acquired HIV After Completion of Vitamin D and Calcium Supplementation

PURPOSE

To determine changes in bone mineral density (BMD) and bone metabolism-related biomarkers among Thai adolescents with perinatally acquired HIV infection (PHIVA) at 3 years following completion of vitamin D and calcium (VitD/Cal) supplementation.

METHODS

An observational follow-up study was conducted among PHIVA who received 48-week VitD/Cal supplementation (either high-dose [3,200 IU/1,200 mg daily] or standard-dose [400 IU/1,200 mg daily]). Lumbar spine BMD (LSBMD) was assessed by dual-energy x-ray absorptiometry. Serum 25-hydroxyvitamin D, intact parathyroid hormone, and bone turnover markers were measured. Changes in LSBMD z-scores and other bone parameters at 3 years after stopping VitD/Cal supplementation compared with baseline or week 48 of supplementation were assessed among participants previously receiving high-dose and standard-dose VitD/Cal supplementation.

RESULTS

Of 114 enrolled PHIVA, 46% and 54% had previously received high-dose and standard-dose VitD/Cal supplementation, respectively. The median age was 20 years; 53% were male. At 3 years after completion of VitD/Cal supplementation, we observed a significant decline in 25-hydroxyvitamin D and increase in intact parathyroid hormone but no significant rebounds of C-terminal telopeptides of collagen type I and procollagen type I amino-terminal propeptides and no significant changes in LSBMD z-scores among PHIVA in both treatment groups, compared with the measurements at week 48 of supplementation. Notably, LSBMD z-scores at 3 years after stopping VitD/Cal supplements were not significantly altered from baseline evaluations in both PHIVA groups.

DISCUSSION

Three years after completion of high-dose or standard-dose VitD/Cal supplementation, LSBMD z-scores of our Thai PHIVA were not significantly changed from baseline and week 48 of supplementation. VitD/Cal supplementation of PHIVA during periods of peak bone mass accrual may have sustained and long-term skeletal benefits.

Age-related trajectory of bone density in children with intestinal failure: A longitudinal retrospective cohort study

BACKGROUND

Longitudinal changes in bone health in children with intestinal failure (IF) are unclear. We aimed to better understand the trajectory of bone mineral status over time in children with IF and identify clinical factors that influence the trajectory.

METHODS

Clinical records of patients attending the Intestinal Rehabilitation Center of Cincinnati Children's Hospital Medical Center between 2012 and 2021 were reviewed. Children diagnosed with IF before age 3 years with at least two lumbar spine dual-energy x-ray absorptiometry scans were included. We abstracted information on medical history, parenteral nutrition, bone density, and growth. We calculated bone density z scores with and without adjustment for height z scores.

RESULTS

Thirty-four children with IF met inclusion criteria. Children were shorter than average with a mean height z score of -1.5 ± 1.3. The mean bone density z score was -1.5 ± 1.3 with 25 of the cohort having a z score < -2.0. After height adjustment, the mean bone density z score was -0.42 ± 1.4 with 11% below -2.0. Most dual-energy x-ray absorptiometry scans (60%) had a feeding tube artifact. Bone density z scores increased slightly with age and lower parenteral nutrition dependency and were higher in scans without an artifact. Etiologies of IF, line infections, prematurity, and vitamin D status were not associated with height-adjusted bone density z scores.

CONCLUSION

Children with IF were shorter than expected for age. Deficits in bone mineral status were less common when adjusting for short stature. Etiologies of IF, prematurity, and vitamin D deficiency were not associated with bone density.

Positions of The International Society for Clinical Densitometry and Their Etiology: A Scoping Review

The International Society for Clinical Densitometry convenes a Position Development Conference (PDC) every 2 to 3 years to make recommendations for guidelines and standards in the field of musculoskeletal measurement and assessment. The recommendations pertain to clinically relevant issues regarding the acquisition, quality control, interpretation, and reporting of measures of various aspects of musculoskeletal health. These PDCs have been meeting since 2002 and have generated 214 Adult, 26 FRAX, 41 pediatric, and 9 general nomenclature consideration positions, for a total of 290 positions. All positions are justified by detailed documents that present the background and rationale for each position. However, the linkage to these publications is not maintained by the ISCD or any other publication such that physicians cannot easily understand the etiology of the positions. Further, the wording of many positions has changed over the years after being reviewed by subsequent PDCs. This scoping review captures the references, changes, and timeline associated with each position through the 2019 PDC. It is meant to serve as a guide to clinicians and researchers for intelligent use and application of the positions.

Trabecular bone score (TBS) and bone mineral density (BMD) analysis by dual X-ray absorptiometry (DXA) in healthy Brazilian children and adolescents: normative data

Childhood and adolescence are crucial periods for healthy bone development throughout life. This study aims to establish normative data for trabecular bone score (TBS) and bone mineral density (BMD) measurements using dual-energy X-ray absorptiometry (DXA) in healthy Brazilian children and adolescents.

PURPOSE

To establish normative data for trabecular bone score (TBS) and bone mineral density (BMD) measurements using dual energy X-ray absorptiometry (DXA) in healthy Brazilian children and adolescents.

METHODS

Healthy children and adolescents, aged 5 to 19 years, underwent medical interview, physical examination with anthropometric measurement, pubertal stage evaluation, and bone densitometry by DXA (Hologic QDR 4500). Boys and girls were divided into 2 age groups: 5-9 years old (children) and 10-19 years old (adolescents). BMD and bone mineral content (BMC) were measured following standard procedures. TBS measurements were performed using the TBS Insight ® v3.0.3.0 software.

RESULTS

A total of 349 volunteers were enrolled in this cross-sectional study. Reference values were defined for each group of children and adolescents divided into 3-year age groups. Girls had lower values of TBS compared to boys (1.356 ± 0.116 and 1.380 ± 0.086 respectively, p = 0.029). For both boys and girls, BMC and spine BMD measurements were significantly higher in adolescent than in children (p = 0.0001; p = 0.0001; p = 0.0001, p = 0.0001, respectively). TBS range increased as pubertal development progressed. In both girls and boys, a 1-year increase in age was associated to a 0.013 increase in TBS. Body mass was a significant determinant for TBS. In girls, a 1 kg/m2 increase in BMI was associated to an average TBS increase of 0.008.

CONCLUSION

Our findings reinforce the evidence that TBS varies according to age, sex, and pubertal stage in healthy children and adolescents. This study established reference values for TBS in healthy Brazilian children and adolescents which can be used as normative data for this population.