Osteoporosis in childhood: bone density of children in health and disease

EFFECTS OF COMBINED HORMONAL CONTRACEPTIVES (CHC) ON BONE HEALTH IN ADOLESCENT GIRLS - A SYSTEMATIC REVIEW

OBJECTIVES

To summarize the effects of combined hormonal contraceptives (CHC) on bone health in adolescent girls.

DESIGN

A systematic search was performed using the following databases: Medline, EMBASE, CINAHL and Cochrane Library clinical trials register, from inception to July 2024.

ELIGIBILITY

Intervention and cohort studies that assessed the use of CHC on bone health in adolescent girls aged 10-19years old were included.

DATA SYNTHESIS

Four randomized control trials and eight observational studies (n =2689) were included.

CONCLUSION

Current evidence indicates that the use of CHC in post-menarchal adolescent girls reduce bone accrual compared to non-users. The negative impact on bone accrual is likely related to the estrogen dose in the CHC preparation, the regimen used and the duration of use.

PROSPERO REGISTRATION NUMBER

PROSPERO CRD 42024574905 on 31 July 2024.

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.

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

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

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

Background

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

Methods

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

Results

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

Conclusions

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

Relationship between nonalcoholic fatty liver disease and bone mineral density in adolescents

Liver metabolism is strongly linked to bone metabolism, and a significant correlation between nonalcoholic fatty liver disease (NAFLD) and bone mineral density (BMD) in adults has been demonstrated. However, the current relationship between NAFLD and BMD in the adolescent population remains controversial. The purpose of this study was to investigate the specific relationship between NAFLD and BMD in adolescents aged 12 to 19 years in the United States. The quantitative relationship between NAFLD and total BMD was investigated using multivariate logistic regression and smoothed fitted curve curves based on multiperspective data from the National Health and Nutrition Examination Survey (NHANES). A total of 740 adolescents were included in this study after excluding unusable samples. The results showed that NAFLD was positively associated with total BMD in adolescents. The results of the subgroup analysis showed that this positive association was mainly found in boys, whites and blacks. The association was not significant in girls, Mexican Americans and other racial groups. Among US adolescents, there was a significant positive association between NAFLD and total BMD, and this relationship varied by gender and race.

Association between total bilirubin and bone mineral density level in adolescents

Background

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

Methods

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

Results

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

Conclusion

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

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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

BACKGROUNDS

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Collagen-binding peptide reverses bone loss in a mouse model of cerebral palsy based on clinical databases

BACKGROUND

Individuals with cerebral palsy (CP) experience bone loss due to impaired weight bearing. Despite serious complications, there is no standard medication.

OBJECTIVE

To develop a new pharmacological agent, we performed a series of studies. The primary aim was to develop an animal model of CP to use our target medication based on transcriptome analysis of individuals with CP. The secondary aim was to show the therapeutic capability of collagen-binding peptide (CBP) in reversing bone loss in the CP mouse model.

METHODS

A total of 119 people with CP and 13 healthy adults participated in the study and 140 mice were used for the behavioral analysis and discovery of therapeutic effects in the preclinical study. The mouse model of CP was induced by hypoxic-ischemic brain injury. Inclusion and exclusion criteria were established for CBP medication in the CP mouse model with bone loss.

RESULTS

On the basis of clinical outcomes showing insufficient mechanical loading from non-ambulatory function and that underweight mainly affects bone loss in adults with CP, we developed a mouse model of CP with bone loss. Injury severity and body weight mainly affected bone loss in the CP mouse model. Transcriptome analysis showed SPP1 expression downregulated in adults with CP who showed lower bone density than healthy controls. Therefore, a synthesized CBP was administered to the mouse model. Trabecular thickness, total collagen and bone turnover activity increased with CBP treatment as compared with the saline control. Immunohistochemistry showed increased immunoreactivity of runt-related transcription factor 2 and osteocalcin, so the CBP participated in osteoblast differentiation.

CONCLUSIONS

This study can provide a scientific basis for a promising translational approach for developing new anabolic CBP medication to treat bone loss in individuals with CP.

Metabolic bone disease in children with intestinal failure is not associated with the level of parenteral nutrition dependency

BACKGROUND & AIMS

Children on long-term home parenteral nutrition (HPN) are at increased risk of suboptimal growth and metabolic bone disease (MBD) i.e. decreased bone mineral density (BMD). The aims of this cross-sectional study were to assess growth and bone health in children on long term HPN and to identify risk factors for MBD.

METHODS

Children above the age of 5 years, stable on HPN for more than 2 years were included. Medical files were reviewed retrospectively and included demographics, gestational age, birth weight and height, indication for PN, age at PN start, duration of PN, number of weekly PN infusions, weight-for-age and height-for-age (SD), body mass index (BMI, kg/m²) as well as blood and urine analyses at the time of Dual X-ray absorptiometry (DXA) measurements. All BMD values were adjusted to statural age which corresponds to the 50th percentile of height. Growth failure (height-for-age ≤ -2SD) and MBD (at least one BMD measurement ≤ -2SD) were analyzed according to the indication of PN, duration of PN and PN dependency index (PNDI) by comparing means and performing logistic regression analysis. PNDI is the ratio of non-protein energy intake in HPN to resting energy expenditure using Schofield equations.

RESULTS

Forty children were assessed at 12.4 ± 4.5 years of age. Mean age at PN start was 1.1 ± 3.6 y (median 0.5). The indications for PN were short bowel syndrome (SBS, n = 21), chronic intestinal pseudo-obstruction syndrome (CIPOS, n = 10) and congenital enteropathies (CE, n = 9). The mean number of PN perfusions was 6 ± 1/week. PNDI was 110 ± 30%. The mean serum level of 25-OHD3 was suboptimal at 26.5 ± 9.1 ng/mL (66.2 ± 22.8 nmol/L). The mean concentrations of calcium, phosphorus, and parathyroid hormone (PTH) were in the normal ranges. Eight children (20%) had PTH levels above normal with low 25-OHD3 levels. The mean weight-for-age and height-for-age Z-scores SDS were 0.4 ± 0.9 and -0.5 ± 1.1 respectively. The actual height was lower than genetic target height (p < 0.001). The BMD Z-scores, adjusted to the 50th percentile of height, of the spine, the left femur and the whole body were: -1.1 ± 1.7, -1.2 ± 1.5 and -1.5 ± 1.8 SDS respectively. Children with CE had significantly lower BMD values than those with SBS and CIPOS (p = 0.01). Only two children had bone fractures after a mild trauma (5%).

CONCLUSIONS

All children on long-term PN, are at risk of low BMD. High dependency on PN (PNDI>120%) and very long-term PN (>10 years) do not appear to increase the risk of growth failure nor MBD. PN-related bone fractures were rare. Close follow-up remains mandatory.

Measurement of Bone Mineral Density in Children with Cerebral Palsy from an Ethical Issue to a Diagnostic Necessity

Introduction

Due to concerns about cumulative radiation exposure in the pediatric population, it is not standard practice to perform dual-energy X-ray absorptiometry (DXA) analysis in the diagnostic process of musculoskeletal disorders, such as cerebral palsy (CP). This study aimed to evaluate the bone mineral density (BMD) in children with CP and the ethical justification of applying DXA analysis in these children. Material and Methods. In this monocentric retrospective analysis, data were collected from children and adolescents with CP who were treated for a primary illness for three years. A clinical examination, which included a DXA analysis, recommended by the multidisciplinary team, was performed. After applying inclusion and exclusion criteria, 60 scans remained for statistical analysis. BMD and Z-scores for the lumbar spine (LS), and hip right and left femoral neck (RFN and LFN, respectively), and total hip (TH) were recorded.

Results

The average age of children with CP when DXA analysis was first performed was about 7 years. The BMD (mean ± SD) at LS (LS-BMD) of all patients was 0.612 ± 0.12, at RFN 0.555 ± 0.11, at LFN 0.572 ± 0.1, and at TH (TH-BMD) 0.581 ± 0.13. The values of the Z-score (mean ± SD) at LS of all patients were −2.5 ± 0.22, at RFN −2.2 ± 0.21, at LFN -2.25 (SD = 0.2), and at TH -2.3 (SD = 0.23). There was no statistical significance between age and gender; however, BMI, walking ability, fracture history, and pattern of CP had a significant impact on BMD and Z-score values of these children.

Conclusion

The results of our study clearly indicate that children with CP have a higher risk of low BMD, osteoporosis, and bone fractures, which makes it ethically justifiable to perform the DXA analysis in these children.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Determinação de minerais no solo e análise de folhas de couve produzida em Brasília

Resumo A couve de folhas é um alimento com alto teor de vitaminas e minerais, que são fundamentais para a dieta humana. Contudo, informações sobre a influência dos fatores extrínsecos e intrínsecos, durante o seu cultivo, em sua composição são escassas. O objetivo deste trabalho foi quantificar os seguintes minerais em folhas de couves produzidas no Distrito Federal (DF): cálcio, magnésio, potássio, fósforo, zinco, manganês, sódio e ferro, correlacionando os teores verificados com os teores presentes no solo. As amostras de folhas e solo foram coletadas em 16 diferentes propriedades rurais no DF, quando também foram aplicados questionários aos produtores sobre as práticas culturais adotadas durante a produção. Os resultados obtidos de teores médios foliares (base em folhas frescas) por 100 g de alimento foram: cálcio, 222,8 mg; ferro, 1,3 mg; magnésio, 37,6 mg, e zinco, 0,6 mg. Esta composição atende a 28% das necessidades diárias de cálcio em crianças de 4 a 8 anos, sendo também supridos 13% de ferro, 29% de magnésio e 13% de zinco, com base no consumo de 100 g de folhas frescas de couve. Foi verificada correlação negativa para teores de magnésio no solo e na folha, com R = -0,69. Para os outros minerais analisados não se verificou correlação significativa. O conteúdo de fósforo e de potássio nos solos foi considerado alto, enquanto que, contrariamente, foram determinadas concentrações baixas de teores de magnésio. O teor de micronutrientes na couve foi considerado baixo e aventa para um manejo inadequado da adubação, fator corroborado pelas respostas dos questionários sobre práticas culturais. Práticas de manejo que levam ao equilíbrio de nutrientes no solo refletem diretamente na interação solo-planta. Recomendações regionais atualizadas de adubação e correção dos solos poderiam auxiliar agricultores e técnicos, refletindo diretamente na obtenção de teores mais equilibrados de micro e macronutrientes em alimentos de origem vegetal.

Low-dose combined oral contraceptive use is associated with lower bone mineral content variation in adolescents over a 1-year period

BACKGROUND

Low-dose combined oral contraceptives (COCs) can interfere with bone mass acquisition during adolescence. This study aimed to evaluate bone mineral density (BMD) and bone mineral content (BMC) in female adolescents taking a standard low-dose COC (ethinylestradiol 20 μg/desogestrel 150 μg) over a 1-year period and to compare their data with those of healthy adolescents from the same age group not taking COCs.

METHODS

This was a non-randomized parallel-control study with a 1-year follow-up. Sixty-seven adolescents aged from 12 to 19 years, divided into COC users (n = 41) taking 20 μg ethinylestradiol/150 μg desogestrel and COC non-user controls (n = 26), were evaluated by bone densitometry examinations at baseline and after 12 months. Comparisons between the groups at the study onset were performed using the Mann-Whitney test with the significance level fixed at 5% or p < 0.05. Comparisons between the groups at the study onset and after 12 months were based on variations in the median percentages for bone mass variables.

RESULTS

The COC users presented with low bone mass acquisition in the lumbar spine, and had BMD and BMC median variations of 2.07% and +1.57%, respectively, between the measurements at baseline and 12 months. The control group had median variations of +12.16% and +16.84% for BMD and BMC, respectively, over the same period. The total body BMD and BMC showed similar evolutions during the study in both groups. Statistical significance (p < 0.05) was seen for the BMC percentage variation between COC users and non-users.

CONCLUSIONS

Use of a low-dose COC (ethinylestradiol 20 μg/desogestrel 150 μg) was associated with lower bone mass acquisition in adolescents during the study period.

TRIAL REGISTRATION

Registry Number, RBR-5h9b3c.

The ever-expanding conundrum of primary osteoporosis: aetiopathogenesis, diagnosis, and treatment

In recent years, as knowledge regarding the etiopathogenetic mechanisms of bone involvement characterizing many diseases has increased and diagnostic techniques evaluating bone health have progressively improved, the problem of low bone mass/quality in children and adolescents has attracted more and more attention, and the body evidence that there are groups of children who may be at risk of osteoporosis has grown. This interest is linked to an increased understanding that a higher peak bone mass (PBM) may be one of the most important determinants affecting the age of onset of osteoporosis in adulthood. This review provides an updated picture of bone pathophysiology and characteristics in children and adolescents with paediatric osteoporosis, taking into account the major causes of primary osteoporosis (PO) and evaluating the major aspects of bone densitometry in these patients. Finally, some options for the treatment of PO will be briefly discussed.

Bone mineral density in developing children with osteogenesis imperfecta: a longitudinal study with 9 years of follow-up

BACKGROUND AND PURPOSE

Osteogenesis imperfecta (OI) is a heritable disorder of connective tissue caused by a defect in collagen type I synthesis. For bone, this includes fragility, low bone mass, and progressive skeletal deformities, which can result in various degrees of short stature. The purpose of this study was to investigate development of bone mineral density in children with OI.

PATIENTS AND METHODS

Development of lumbar bone mineral density was studied retrospectively in a cohort of 74 children with OI. Mean age was 16.3 years (SD 4.3). In 52 children, repeated measurements were available. Mean age at the start of measurement was 8.8 years (SD 4.1), and mean follow-up was 9 years (SD 2.7). A longitudinal data analysis was performed. In the total cohort (74 children), a cross-sectional analysis was performed with the latest-measured BMD. Age at the latest BMD measurement was almost equal for girls and boys: 17.4 and 17.7 years respectively.

RESULT

Mean annual increase in BMD in the 52 children was 0.038 g/cm(2)/year (SD 0.024). Annual increase in BMD was statistically significantly higher in girls, in both the unadjusted and adjusted analysis. In cross-sectional analysis, in the whole cohort the latest-measured lumbar BMD was significantly higher in girls, in the children with OI of type I, in walkers, and in those who were older, in both unadjusted and adjusted analysis.

INTERPRETATION

During 9 years of follow-up, there appeared to be an increase in bone mineral density, which was most pronounced in girls. One possible explanation might be a later growth spurt and older age at peak bone mass in boys.

[Preliminary comparison between phalangeal quantitative ultrassonography and bone densitometry for bone mass evaluation in adolescents]

OBJECTIVE

To evaluate the association between quantitative ultrasonography at hand phalanges (QUS) and dual energy X-ray absorptiometry (DXA), and between these methods with food intake and history of bone fractures.

SUBJECTS AND METHODS

After two years of follow up of 270 schoolchildren, 10 of them, who showed bone mass below - 2 SD in QUS, were included in the present study. Laboratory results and DXA data were analyzed.

RESULTS

Bone mass evaluated by DXA at L1-L4 ranged from -2.8 to -1.1 SDS, and whole body bone mass, from -2.9 to -1.2 SDS. Three children had history of non-pathological bone fractures. Dietary assessment showed low intake of calcium in 10 cases, of phosphorus in 6, and of vitamin D in 8 cases. There were no differences among the cases of bone mass below-2 SD in any of the three used methods. There was no association between history of bone fractures and food intake, and between these evaluations and bone mass.

CONCLUSION

In this small group of schoolchildren there was an association between the methods QUS and DXA. However, there was no association between bone mass and the history of bone fractures, or calcium, phosphorus and vitamin D intake.

Bone mineral density in healthy female adolescents according to age, bone age and pubertal breast stage

Objectives:

This study was designed to evaluate bone mineral density (BMD) in healthy female Brazilian adolescents in five groups looking at chronological age, bone age, and pubertal breast stage, and determining BMD behavior for each classification.

Methods:

Seventy-two healthy female adolescents aged between 10 to 20 incomplete years were divided into five groups and evaluated for calcium intake, weight, height, body mass index (BMI), pubertal breast stage, bone age, and BMD. Bone mass was measured by bone densitometry (DXA) in lumbar spine and proximal femur regions, and the total body. BMI was estimated by Quetelet index. Breast development was assessed by Tanner’s criteria and skeletal maturity by bone age. BMD comparison according to chronologic and bone age, and breast development were analyzed by Anova, with Scheffe’s test used to find significant differences between groups at P≤0.05.

Results:

BMD (g·cm^-2) increased in all studied regions as age advanced, indicating differences from the ages of 13 to 14 years. This group differed to the 10 and 11 to 12 years old groups for lumbar spine BMD (0.865±0.127 vs 0.672±0.082 and 0.689±0.083, respectively) and in girls at pubertal development stage B3, lumbar spine BMD differed from B5 (0.709±0.073 vs 0.936±0.130) and whole body BMD differed from B4 and B5 (0.867±0.056 vs 0.977±0.086 and 1.040±0.080, respectively).

Conclusion:

Bone mineralization increased in the B3 breast maturity group, and the critical years for bone mass acquisition were between 13 and 14 years of age for all sites evaluated by densitometry.

Low bone mass in patients with motor disability: prevalence and risk factors in 59 Finnish children

AIM

Children with motor disabilities are at increased risk of compromised bone health. This study evaluated prevalence and risk factors of low bone mass and fractures in these children.

METHOD

This cross-sectional cohort study evaluated bone health in 59 children (38 males, 21 females; median age 10 y 11 mo) with motor disability (Gross Motor Function Classification System levels II-V). Bone mineral density (BMD) in the lumbar spine was measured with dual-energy X-ray absorptiometry; BMD values were corrected for bone size (bone mineral apparent density [BMAD]) and skeletal maturity, and compared with normative data. Spinal radiographs were obtained to assess vertebral morphology. Blood biochemistry included vitamin D concentration and other parameters of calcium homeostasis.

RESULTS

Ten children (17%) had sustained in total 14 peripheral fractures; lower-limb fractures predominated. Compression fractures were present in 25%. The median spinal BMAD z-score was -1.0 (range -5.0 to 2.0); it was -0.6 in those without fractures and -1.7 in those with fractures (p=0.004). Vitamin D insufficiency was present in 59% of participants (serum 25-hydroxyvitamin D <50 nmol/l) and hypercalciuria in 27%. Low BMAD z-score and hypercalciuria were independent predictors for fractures.

INTERPRETATION

Children with motor disability are at high risk of peripheral and vertebral fractures and low BMD. Evaluation of bone health and prevention of osteoporosis should be included in the follow-up.

Extracutaneous manifestations and complications of inherited epidermolysis bullosa: part II. Other organs

It is well known, primarily via case reports and limited case series, that nonepithelial tissues may become injured in patients with epidermolysis bullosa. Only recently, however, have there been data generated from large, well characterized cohorts. Our objective is to provide dermatologists with a comprehensive review of each of these major extracutaneous complications, with a summary of the pertinent literature and evidence-based recommendations for surveillance, evaluation, and management. Some epidermolysis bullosa subtypes are at risk for severe injury of the bone marrow, musculoskeletal system, heart, kidney, and teeth, and for the development of squamous cell carcinoma, basal cell carcinoma, or malignant melanoma. If untreated, significant morbidity or mortality may result.

Is the treatment for childhood solid tumors associated with lower bone mass than that for leukemia and Hodgkin disease?

BACKGROUND

Cancer disease and its therapy (e.g., chemotherapeutic agents such as glucocorticoids, methotrexate, antymetabolities, cranial and local irradiation) may severely disturb normal growth, bone mineral acquisition, and skeletal development because most individuals go through the stages of rapid growth when childhood cancer is diagnosed.

PROCEDURES

To identify factors associated with reduced bone mineral density (BMD) in survivors of childhood cancer the authors examined 114 patients (70 males) who had been treated for acute lymphoblastic leukemia (ALL; n = 43), Hodgkin disease (HD; n = 35), and solid tumors (ST; n = 36) twice. Median age at diagnosis was 8.4 years; at the consecutive examinations it was 12.8 and 16.3 years, respectively. To assess bone density we used dual-energy x-ray absorptiometry (DXA).

RESULTS

In the first examination, patients with a history of steroid therapy had higher total and spine BMD and higher BMI (body mass index) than those who were not given steroids. At the end of the follow-up, no differences were found in BMD between subgroups, although BMI was still higher in both ALL and HD patients than in those with ST.

CONCLUSIONS

Patients treated for solid tumors have reduced bone mass. Low BMI and local irradiation seem to be the factors responsible for reduced BMD in children treated for ST. The use of steroids does not disturb bone mass accumulation in patients treated for childhood malignancies. However, a long-term effect of cancer treatment on osteoporosis risk remains to be determined.

Low bone density in children with hypercalciuria and/or nephrolithiasis

The objective of this study was to identify how many children with hypercalciuria and/or nephrolithiasis have a low bone density and whether the risk of low bone density can be identified by 24-h urine stone-risk profiles and/or growth parameters. A retrospective chart review was performed on 110 idiopathic hypercalciuria and/or kidney stone patients who received both a 24-h urine for stone-risk profile and a dual-energy X-ray densitometry scan. Patients were divided into low bone density vs. normal bone density groups and hypercalcuria verus nephrolithiasis groups and analyzed for differences in growth parameters, urine stone-risk profiles, and bone densities. Overall, 47% had a bone density z score < -1, and 26% had a bone density z score < -2. Patients with a low bone density had a higher body mass index and lower urine creatinine and ammonium than those with a normal bone density. Patients with nephrolithiasis had a lower bone density z score than patients with hypercalcuria and no nephrolithiasis. Clinicians should be aware of the increased incidence of low bone density in children with hypercalciuria and nephrolithiasis. The effect of hypercalciuria and nephrolithiasis treatment on bone density and the natural progression of the bone density in the studied patient population warrants further investigation.

Implementing an intervention to improve bone mineral density in survivors of childhood acute lymphoblastic leukemia: BONEII, a prospective placebo-controlled double-blind randomized interventional longitudinal study design

The BONEII study is a large two-phase study. The baseline study (Study 1) aims to estimate the prevalence of diminished bone mineral density (BMD) in patients treated for childhood acute lymphoblastic leukemia (ALL) and identify risk factors for BMD deficits. The interventional phase (Study 2) of BONEII has a placebo-controlled double-blind randomized longitudinal design to evaluate the effects of nutritional counseling and calcium and vitamin D supplementation on changes in BMD and serum and urine markers of bone metabolism. The extensive information being collected through this large study will serve as a repository of relational data about BMD and bone turnover and will support further investigations to assess the association of calcium metabolism, bone turnover, nutritional intake, lifestyle factors (such as exercise and the use of alcohol and tobacco), and the specific agents used in ALL therapy in this rapidly increasing population of childhood cancer survivors.

Bone metabolism in celiac disease

OBJECTIVE

To investigate the prevalence of both calcium metabolism alterations and bone defects in children with celiac disease (CD).

STUDY DESIGN

We studied 54 untreated patients with CD (mean age, 7 years). We compared the serum concentration of calcium, magnesium, 25(OH)vitamin D3, alkaline phosphatase, and parathyroid hormone (PTH) of patients with CD with those of 60 healthy children. Children with CD with 2 laboratory alterations underwent DEXA examination, which was evaluated after 6 months of a gluten-free diet (GFD).

RESULTS

The calcium and the 25(OH)vitamin D3 levels were lower in children with CD than in control subjects, and the PTH level was higher in children with CD than in control subjects (P < .001). Hyperparathyroidism was found in 29 children with CD. Twenty patients tested positive for 2 laboratory alterations, and 10 of them were osteopenic. After 6 months of GFD calcium, 25(OH)vit.D3 and PTH levels normalized, with the improvement of bone mineral density.

CONCLUSIONS

Calcium metabolism defects are common in untreated children with CD, and they returned to normal after GFD. A detailed, time-consuming, and expensive study of bone metabolism is not necessary in children with CD shortly exposed to gluten who follow the GFD.

Osteoporosis in children with cancer

As increasing numbers of childhood cancer patients are surviving, the long-term complications of the disease and its treatment have become ever more increasingly important. Reduced bone mineral density and increased fracture risk have been reported during and after treatment of children with cancer. The causes of osteoporosis are multifactorial. Among others, the disease itself, chemotherapy, irradiation and genetic susceptibility play a role. Bone mineral density in later life depends largely on the peak bone mass achieved in adolescence or young adulthood. Therefore, optimizing peak bone mass is of clinical importance. Preventive and therapeutic strategies, such as calcium and vitamin D supplementation, physical activity and bisphosphonates, are considered.

Osteopenia and cancer in children and adolescents: the fragility of success

The attainment of a satisfactory peak bone mass, which is accomplished largely by the end of adolescence, is the best protection against excessive bone mineral loss in late adulthood. Factors that influence this process include age, race, sex, body size, pubertal status, diet, physical activity, and other lifestyle elements. Cancer and its treatment in children and teenagers adversely impact bone mineralization. In particular, chemotherapy (especially glucocorticosteroids and methotrexate) and cranial irradiation (apparently by reducing growth hormone secretion and by causing hypogonadotropic hypogonadism) interfere with normal bone turnover. Resorption often exceeds formation, resulting in net bone mineral loss and providing a rational basis for the use of antiresorptive drugs. Such osteopenia may be symptomatic, with pain and abnormal gait, and increases the risk of fractures several fold. The disorder is compounded by reduced physical activity, so programs to reduce this deficit are of measurable benefit. All of those engaged in the care of children and adolescents with cancer have an opportunity to improve the bone health of these young people and to limit their risk of developing osteoporosis and fragility fractures in adult life.

Osteoporosis in children and adolescents: etiology and management

Bone mass increases progressively during childhood, but mainly during adolescence when approximately 40% of total bone mass is accumulated. Peak bone mass is reached in late adolescence, and is a well recognised risk factor for osteoporosis later in life. Thus, increasing peak bone mass can prevent osteoporosis. The critical interpretation of bone mass measurements is a crucial factor for the diagnosis of osteopenia/osteoporosis in children and adolescents. To date, there are insufficient data to formally define osteopenia/osteoporosis in this patient group, and the guidelines used for adult patients are not applicable. In males and females aged <20 years the terminology 'low bone density for chronologic age' may be used if the Z-score is less than -2. For children and adolescents, this terminology is more appropriate than osteopenia/osteoporosis. Moreover, the T-score should not be used in children and adolescents. Many disorders, by various mechanisms, may affect the acquisition of bone mass during childhood and adolescence. Indeed, the number of disorders that have been identified as affecting bone mass in this age group is increasing as a consequence of the wide use of bone mass measurements. The increased survival of children and adolescents with chronic diseases or malignancies, as well as the use of some treatment regimens has resulted in an increase in the incidence of reduced bone mass in this age group. Experience in treating the various disorders associated with osteoporosis in childhood is limited at present. The first approach to osteoporosis management in children and adolescents should be aimed at treating the underlying disease. The use of bisphosphonates in children and adolescents with osteoporosis is increasing and their positive effect in improving bone mineral density is encouraging. Osteoporosis prevention is a key factor and it should begin in childhood. Pediatricians should have a fundamental role in the prevention of osteoporosis, suggesting strategies to achieve an optimal peak bone mass.

No difference between prednisolone and dexamethasone treatment in bone mineral density and growth in long term survivors of childhood acute lymphoblastic leukemia

BACKGROUND

Dexamethasone is known to have both more potent leukemic activity and is associated with a higher incidence of side effects than prednisolone. In this study, we compared the long-term effects of dexamethasone and prednisolone on bone mineral density (BMD), body composition and growth in long-term survivors of ALL in first complete remission.

PROCEDURE

Ninety patients (51 male, 49 female; 8.6-38.5 year), treated with either a prednisolone containing protocol (n = 47; n = 19 also with CNS-irradiation) or a dexamethasone containing protocol (n = 43; no cranial irradiation) participated in this cross-sectional single center study. Mean follow-up was 12.7 years (2.0-29.7 years). BMD of lumbar spine and total body, and body composition were expressed as standard deviation scores (SDS) using dual energy X-ray absorptiometry. Bone mineral apparent density of the lumbar spine (BMAD) was calculated to correct for bone size.

RESULTS

There was no difference in height, height corrected for target height, BMD, or lean body mass between prednisolone and dexamethasone treated patients. Prednisolone treated patients had an increased percentage body fat (SDS +0.46; P < 0.05) and increased body mass index (SDS 0.88; P < 0.01) compared to normal. Dexamethasone treated patients had only an increased body mass index (SDS 0.52; P < 0.05). Height, total body BMD, and lean body mass were lower in patients treated with cranial irradiation as compared to non-irradiated patients, but differences in the latter two disappeared when corrected for height. BMAD was normal after CNS-irradiation.

CONCLUSIONS

Long term survivors of ALL treated with prednisolone or dexamethasone containing regimens do not differ in height, BMD, or body composition.

Large variations occur in bone density measurements of children when using different software

BACKGROUND

Paediatric dual X-ray absorptiometry (DXA) studies present a number of technical problems. One of these is that the edge detection algorithms designed for the adult skeleton may fail for paediatric studies. Hologic provide alternative algorithms for low bone density studies.

AIM

To assess low-density software for the analysis of paediatric DXA studies and to compare with the adult protocol.

METHODS

Our centre has scanned 450 normal children as part of a normal range study. A subgroup of 103 children was selected using a random number generator. The group was distributed evenly between males and females and across the age range 5-17 years. Each individual underwent both a lumbar spine and a whole-body scan on a Hologic QDR-4500W DXA scanner. Both scans were analysed using the standard adult protocol and then re-analysed using the Hologic experimental paediatric protocol for whole body and the Hologic low-density protocol for lumbar spine.

RESULTS

Both lumbar spine protocols showed an increase in bone mineral density with age; however, the low-density protocol always produced a lower bone mineral density result than the adult protocol. Bland-Altman analysis showed limits of agreement of 0.031-0.093 g x cm(-2) (male, 0.032-0.089 g x cm(-2); female, 0.031-0.096 g x cm(-2)). This represents a mean difference of 9%. Five results showed differences greater than the upper limit of agreement. All these cases were children under 11 years of age who had large areas of spine not identified as bone by the adult protocol. These children were all below the 30th percentile for the body mass index. The whole-body protocols showed similar increases in bone mineral density with age; however, the experimental paediatric protocol always produced a lower bone mineral density result than the adult protocol. Paired results showed limits of agreement of 0.0668-0.130 g x cm(-2) (male, 0.063-0.124 g x cm(-2); female, 0.073-0.134 g x cm(-2)). This represents a mean difference of 11%. Five results showed differences greater than the upper limit of agreement.

CONCLUSIONS

For anteroposterior (AP) lumbar spine scans, the use of the paediatric algorithm in children under 11 years of age would prevent the largest failures in analysis. For whole-body scanning, the adult algorithm showed no major failures in children of 11 years or older. It is hoped that forthcoming improvements in whole-body density analysis will improve the results for those under 11 years of age. Normal range data should be generated for any new algorithm to allow proper interpretation of clinical studies.

Bone density at the os calcis: reference values, reproducibility, and effects of fracture history and physical activity

AIMS

To establish reference values for bone mineral density (BMD) measured at the os calcis (OC) in healthy UK Caucasian children. Secondary objectives were to assess the reproducibility of the measurement and the effects of fracture history and habitual physical activity.

METHODS

A total of 403 children aged 5-18 were studied. Main outcome measures were: BMDoc measured by peripheral DXA, total BMD measured by whole body axial scanner, age, anthropometry, pubertal status, self-reported fracture history, and physical activity (PA) expressed as a three point score.

RESULTS

Complete data were available on 171 girls and 123 boys free of a history of fracture. BMDoc was related positively to age, body size, and total BMD, and could be predicted using a proportional model based on height alone (R2: 65% girls, 77% boys). Mean BMDoc appears to plateau in girls at 15 years and attain a value that concurs with the mean peak value in adult women. The 95% limits of agreement in repeated measures were -0.029 to 0.029 g/cm2 (n = 53). Compared with sedentary children, those doing regular sports or PA for more than five hours a week had an increased BMDoc (by about 0.03 g/cm2 or about 7% of the overall mean). A history of fracture (n = 81) was associated with a reduced BMDoc in boys but not in girls, though our study may have been underpowered for a subgroup analysis.

CONCLUSIONS

BMDoc can be measured easily and quickly in children older than 5 years and provides an objective measure of areal bone density for clinical and research studies using a reference range derived from its relation to height.

[Bone mineral density in children with osteogenesis imperfecta]

OBJECT

Osteogenesis imperfecta is the term used for a group of disorders of collagen synthesis which cause increased bone fragility. The aim of our study was to evaluate the BMD in patients with OI.

MATERIAL AND METHODS

We used dual-energy x ray absorptiometry, Hologic QDR 4500W (DEXA), to compare the bone mineral density (BMD) of 8 patients aged from 3 years to 20 years who had osteogenesis imperfecta with an age and sex matched control group.

RESULTS

DEXA detected highly significant differences in BMD respecting control group. The mean BMD in the patients with osteogenesis imperfecta was 62.6 % of normal in lumbar spine (p < 0.01) and 63.01 % of normal in the femoral neck (p < 0.01) using Wilcoxon test.

CONCLUSION

DEXA is an objective, reproductible and sensitive method of measurement of BMD in children. It may help to stablish the diagnosis, to asses prognosis and possibly to monitor the response to different types of treatment.

Genotype-phenotype relationship in human ATP6i-dependent autosomal recessive osteopetrosis

Autosomal-recessive osteopetrosis is a severe genetic disease caused by osteoclast failure. Approximately 50% of the patients harbor mutations of the ATP6i gene, encoding for the osteoclast-specific a3 subunit of V-ATPase. We found inactivating ATP6i mutations in four patients, and three of these were novel. Patients shared macrocephaly, growth retardation and optic nerve alteration, osteosclerotic and endobone patterns, and high alkaline phosphatase and parathyroid hormone levels. Bone biopsies revealed primary spongiosa lined with active osteoblasts and high numbers of tartrate-resistant acid phosphatase (TRAP)-positive, a3 subunit-negative, morphologically unremarkable osteoclasts, some of which located in shallow Howship lacunae. Scarce hematopoietic cells and abundant fibrous tissue containing TRAP-positive putative osteoclast precursors were noted. In vitro osteoclasts were a3-negative, morphologically normal, with prominent clear zones and actin rings, and TRAP activity more elevated than in control patients. Podosomes, alphaVbeta3 receptor, c-Src, and PYK2 were unremarkable. Consistent with the finding in the bone biopsies, these cells excavated pits faintly stained with toluidine blue, indicating inefficient bone resorption. Bone marrow transplantation was successful in all patients, and posttransplant osteoclasts showed rescue of a3 subunit immunoreactivity.

Bone metabolism in childhood rheumatic disease

There is an increasing appreciation among physicians about the importance of bone health in children as a potential modifiable risk factor for development of osteoporosis later in life. Many unanswered questions about normal pediatric bone health make the treatment and clinical investigation of bone disease in children with chronic rheumatic diseases challenging. Understanding normal bone biology along with the epidemiology and diagnosis of osteoporosis is the key to the understanding of the potential for abnormal bone metabolism in the juvenile rheumatic diseases.

Bone metabolism in children with epidermolysis bullosa

We evaluated bone mineral density, vitamin D status, and biochemical markers of bone turnover in seven children with epidermolysis bullosa (EB). Four had osteopenia (Z score, -1.5) and four 25(OH) vitamin D <34 nmol/L (14 ng/mL), two of which had hyperparathyroidism. Children with severe EB should have evaluation of bone metabolism.