Bone Mineral Content In Children Research Articles

P-780 Bone health in Danish children aged 7-10 years born after assisted reproductive technology with frozen and fresh embryo transfer

Abstract Study question Is bone health in children conceived after frozen embryo transfer (FET) different from children conceived after fresh embryo transfer (fresh-ET) and natural conception (NC)? Summary answer FET-children had higher bone mineral density (BMD) and bone mineral content (BMC) compared to fresh-ET-children. Insulin-like-growth-factor-I (IGF-I) levels and lean bodymass were similar between groups. What is known already Children conceived after assisted reproductive technology (ART) with FET have a higher average birthweight (BW) and increased risk of being born large-for-gestational-age (LGA) while children born after fresh-ET are more often born small-for-gestational-age (SGA). In general, BW is a determinant of BMD and BMC in childhood with LGA being associated with higher BMD and BMC compared to children born appropriate-for-gestational-age. The relationship between BW and BMD and BMC may be mediated by IGF-I levels and lean bodymass as IGF-I is an important regulator of muscle and bone development. Bone health in children born after ART is scarcely explored. Study design, size, duration This study was part of the large Danish cohort study “Health in Childhood following Assisted Reproductive Technology” (HiCART) which included 606 singletons (292 boys) born in Denmark between 2009 and 2013. The children were conceived after FET (n = 200), fresh-ET (n = 203) and NC (n = 203) and matched for birth year and sex. The study examinations were performed from January 2019 to September 2021. Participants/materials, setting, methods The children underwent a clinical examination at 7-10 years of age with anthropometric measurements, pubertal staging, a fasting blood sample and a whole-body dual-energy x-ray absorptiometry-scan (DXA). Anthropometric measurements and circulating growth factors were converted to standard deviation scores (SDS) using Danish reference material. The study groups were compared pairwise using univariate linear regression and multiple linear regression adjusting for relevant confounders including sex, age, puberty, maternal pregestational BMI, breastfeeding and BW (SDS). Main results and the role of chance Children conceived after FET had significantly higher BW (SDS) (mean, SD: 0.20 SDS, 1.09) compared to children conceived after fresh-ET (-0.22 SDS, 1.00), mean difference: 0.42 SDS (95% CI: 0.21; 0.62) and NC (-0.16 SDS, 1.09), mean difference: 0.35 SDS (95% CI: 0.14; 0.57). In the adjusted model, children born after FET had significantly higher total BMD (g/cm2) (mean difference 0.01, 95% CI: 0.00; 0.03) and size-adjusted BMC (BMC/height, g/m) (mean difference 0.21, 95% CI: 0.01; 0.40) compared to children born after fresh-ET. There was no significant difference in total BMD or BMC/height when comparing FET and fresh-ET to NC children, respectively. There was a trend towards higher lean bodymass (g) in children born after FET and lower lean bodymass in children born after fresh-ET compared to NC children, however this did not reach the level of significance. IGF-I (SDS), IGF-binding-protein-3 (SDS) and serum calcium (mmol/L) levels were comparable between the groups. In the entire cohort, there was a significantly positive correlation between BW (SDS) and size-adjusted BMC (BMC/height, g/m) (b: 0.21, 95% CI: 0.14; 0.27) and total lean bodymass (g) (b: 755, 95% CI: 531; 978), while a significantly negative correlation with IGF-I (SDS) (b: -0.07, 95% CI: -0.13; -0.01). Limitations, reasons for caution The study was powered to detect a clinically relevant difference in BMI (SDS), the primary outcome. Hence, secondary analyses are exploratory by nature. We have no information regarding endometrial preparation protocol in the FET-cycles which may bias the results. Multiple testing may increase our risk of type I errors. Wider implications of the findings Reassuringly, BMD and size-adjusted BMC in children born after ART with FET and fresh-ET were comparable to NC children. Potential determinants of BMD and BMC (IGF-I and lean bodymass) were also similar. Increased BMD and size-adjusted BMC in FET compared to fresh-ET suggests that the different BW-profiles play a role. Trial registration number NCT03719703

Effects of exercise on bone mineral content in children and adolescents at different growth stages: a Meta-analysis

To evaluate the effect of exercise on bone mineral content(BMC) in children and adolescents at different growth stages. EMBASE, PubMed, Web of Science, CNKI, VIP database and Wanfang database were searched. The randomized controlled trials(RCTS) published in Chinese and English on the effects of exercise on BMC in children and adolescents were collected using exercise, children, adolescents and BMC as search terms. Cochrane collaboration tool was used to evaluate the quality of the included studies, and RevMan5.4 software was used for Meta-analysis. The search time limit is from the establishment of the database to July 20, 2022. A total of 18 articles(22 RCTS) involving 1305 children and adolescents were included. The result of the Meta-analysis showed that: Compared with the control group, (1) exercise significantly improved spinal BMC(SMD=0.28, 95%CI 0.17-0.40, P<0.01) and femoral neck BMC(SMD=0.40, 95%CI 0.20-0.61, P<0.01), but not for systemic BMC(SMD=0.08, 95%CI-0.04-0.21, P=0.19). (2) Subgroup analysis showed that exercise significantly improved spinal BMC in the following stages: prepubertal(SMD=0.48, 95%CI 0.27-0.69, P<0.01)and early pubertal(SMD=0.22, 95%CI 0.05-0.39, P=0.01). The stages in which exercise significantly improved femoral neck BMC were as follows: prepubertal(SMD=0.60, 95%CI 0.05-1.16, P=0.03), early pubertal(SMD=0.22, 95%CI 0.01-0.43, P=0.04), middle and late pubertal(SMD=0.43, 95%CI 0.13-0.72, P<0.01). Exercise significantly enhanced spinal BMC during preadolescence and early adolescence as well as femoral neck BMC throughout childhood and adolescence, especially with higher effect sizes during preadolescence.

The Benefits to Bone Health in Children and Pre-School Children with Additional Exercise Interventions: A Systematic Review and Meta-Analysis.

Determine if exercise interventions, beyond what is already provided to children and preschool children, improve bone health and reduce fracture incidence. Systematic review and meta-analysis reported using the PRISMA guidelines. Certainty of evidence was assessed using GRADE recommendations. Five electronic databases were searched for records: PUBMED; CINAHL; CENTRAL; SPORTDiscus; Web of Science. Randomised, quasi-randomised and non-randomised controlled trials (including cluster-randomised) assessing the impact of additional exercise interventions (e.g., increased physical education classes or specific jumping programs) on bone health in children (6-12 years) and pre-school children (2-5 years) without dietary intervention. Thirty-one records representing 16 distinct clinical trials were included. Dual-energy X-ray Absorptiometry (DXA) and/or peripheral Quantitative Computed Tomography (pQCT) were used to quantify bone health. Increased femoral neck bone mineral content in children with additional exercise interventions (n = 790, SMD = 0.55, 95% CI = 0.01 to 1.09) was reported, however this was not significant following sensitivity analysis. Other DXA and pQCT measures, as well as fracture incidence, did not appear to significantly differ over time between intervention and control groups. No studies reported adverse events. Studies failed to report all domains within the TIDieR checklist. All studies were at high risk of bias using the Cochrane RoB Tool 2.0. The certainty of the evidence was very low. The addition of exercise interventions, beyond what is provided to children, does not appear to improve DXA and pQCT measures of bone health. The effect of additional exercise interventions on bone health in pre-school children is largely unknown. Future trials should ensure adherence is clearly reported and controlled for within analysis as well as including reports of adverse events (e.g., apophysitis) that occur due to increased exercise interventions.

Bone Mineral Content Prediction by Bioelectrical Impedance Analysis in Children and Adolescents Diagnosed with HIV Infection: Comparison with Dual Energy X-ray Absorptiometry: A Cross-Sectional Study

A body composition analysis has been used to investigate alterations on body tissues in children and adolescents diagnosed with human immunodeficiency virus (HIV) infection, such as low bone mineral content (BMC). The study aimed to developed equations to estimate the BMC in children and adolescents diagnosed with HIV based on a bioelectrical impedance analysis (BIA) using dual energy X-ray absorptiometry (DXA) as a reference method. This is a cross-sectional study conducted with children and adolescents diagnosed with HIV infection. Their body composition was evaluated by BIA and DXA. Linear multiple regression models were constructed to estimate the BMC. Sixty-four children and adolescents aged 8–15 years (12.22 ± 2.13) who were diagnosed with HIV infection participated in the study. The models were substantially correlated with the BMC values, and they explained 82–91% of the BMC, with no differences between DXA and values as estimated by the models. The model with the highest estimate of the BMC (91% of explanation) and the lowest error (SEE of 0.011 kg) included the following variables: body mass, fat mass, total 50 kHz reactance, TCD4 lymphocytes, antiretroviral therapy type, and %TCD4 lymphocytes. The models had a clinically acceptable correlation and low SEE values. The BIA was suitable to estimate the BMC in children and adolescents diagnosed with HIV.

Leptin levels were negatively associated with lumbar spine bone mineral content in children with overweight or obesity.

AimAdipokines seem to play a role in bone morphogenesis, although this also depends on the mechanical forces applied to the skeleton. The aim was to assess the relationships of resting leptin and adiponectin with bone parameters and whether high muscular fitness levels affect these relationships in children with overweight or obesity.MethodsThis cross‐sectional study took part from 2014 to 2016 in Granada, Spain. Participants were recruited from University Hospitals, and we also used advertisements in local media and school contacts in the city. Adipokines were analysed in plasma. Muscular fitness was assessed by one repetition maximum in bench and leg press tests. Dual‐energy X‐ray absorptiometry was used to measure bone parameters.ResultsWe included 84 children (10.0 ± 1.2y; 63% boys) in this analysis. Leptin was negatively associated with lumbar spine bone mineral content (β = −0.162, p = 0.053). No significant interaction was found for muscular fitness. Simple slope estimates suggested that children performing more than 133.3 kg in leg press test ameliorated the negative association between leptin and lumbar spine bone mineral content.ConclusionLeptin levels were negatively associated with lumbar spine bone mineral content in children with overweight or obesity. A high muscular fitness at the lower body could counteract this association.

Influences on Skeletal Health and Bone Mineralization in Children.

Bone is in its most active formation phase of mineralization in the pediatric and adolescent population. Peak bone mass is achieved around the late teens to early 20s. Deficient bone mineralization and decreased peak bone mass acquisition predispose an individual to childhood fractures or lifelong fracture risk. Adolescent fragility or stress fractures should prompt a secondary evaluation for the causes of a low bone mineral content, the root of a fracture. The purpose of this article is to review published literature that discusses the risk factors associated with a decreased bone mineral content in children from birth to the age of peak bone mass. The article also includes a public health planning model for pediatric osteoporosis.

Consumption of Very Low Mineral Water Is Associated with Lower Bone Mineral Content in Children

Our previous study found that consumption of very low mineral drinking water may retard height development in schoolchildren; however, its association with bone modeling remained unknown. The aim of this study was to investigate the influence of very low mineral water on biomarkers of bone modeling in children. A retrospective cohort study was conducted among 2 groups of 10-13-y-old children who had consumed drinking water with normal mineral contents (conductivity 345 μs/cm, the NW group including 119 boys and 110 girls) or very low mineral contents (conductivity 40.0 μs/cm, the VLW group including 223 boys and 208 girls) in school for 4 y. Differences in daily total mineral intakes, developmental parameters, serum biomarkers of osteoblast activity, and bone formation and resorption between the 2 groups were analyzed with independent t test and chi-square test. Associations of developmental parameters and serum biomarkers with Ca intake from drinking water were analyzed with multiple linear regression and binary logistic regression. Compared with the NW group, the VLW group had lower daily Ca intake, height increase, bone mineral content (BMC), osteoblast activity [serum bone alkaline phosphatase (BALP)] (means±SDs: 433±131 mg, 16.6±8.27 cm, 1.92±0.431 kg, and 9.28±1.42 μg/L compared with 497±155 mg, 22.3±8.45 cm, 2.14±0.354 kg, and 11.0±0.823 μg/L, respectively, P<0.001), and higher bone resorption [serum crosslinked C-telopeptide of type I collagen (CTX), mean±SD: 142±46.9 nmol/L compared with 130±40.6 nmol/L, P=0.001). Ca intake from drinking water was positively associated with height increase, BMC, and BALP (β: 0.0667, 95% CI: 0.0540, 0.0793; β: 3.22, 95% CI: 2.37, 4.08; and β: 23.9, 95% CI: 20.6, 27.2), respectively, P<0.001), and was negatively associated with CTX (β: -0.206, 95% CI:-0.321, -0.0904, P<0.001). These changes suggested that consumption of very low mineral water may be associated with osteoblast inhibition, bone resorption activation, bone mineral reduction, and height development retardation. The health risk of consuming very low mineral water should be considered in children.

Effects of Dairy Product Consumption on Height and Bone Mineral Content in Children: A Systematic Review of Controlled Trials

There is a physiological basis for the roles of selected nutrients, especially proteins, calcium, and vitamin D, in growth and development, which are at a maximum during the pediatric period. Milk and dairy products are particularly rich in this group of nutrients. The present systematic review summarizes the available evidence relating dairy product intake with linear growth and bone mineral content in childhood and adolescence. A search was conducted in the MEDLINE (via PubMed) and SCOPUS databases following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and included intervention-controlled clinical trials with dairy products in children from 1 January, 1926 to 30 June, 2018. The risk of bias for each study was assessed using the Cochrane methodology. The number of study participants, the type of study and doses, the major outcomes, and the key results of the 13 articles included in the review are reported. The present systematic review shows that supplementing the usual diet with dairy products significantly increases bone mineral content during childhood. However, the results regarding a possible relation between dairy product consumption and linear growth are inconclusive.

Effect of Vitamin D and Calcium Supplementation on Bone Mineral Content in Children with Thalassemia

To evaluate the effect of vitamin D and calcium supplementation for osteoprotection in thalassemia. 29 children (age 2-12 y) were supplemented with oral vitamin D (1000 IU/d) and calcium (500 mg/d) for 1 year. The dual energy X-ray absorptiometry (DXA) was done to assess bone mineral content at baseline and 12 months. Serum 25-hydroxy vitamin D, intact parathyroid hormone, osteocalcin, calcium, phosphate, alkaline phosphatase, and spot urine deoxypyridinoline (DPD)/creatinine were done at baseline, 6 months and 12 months. The mean (SD) bone mineral content increased from baseline value of 8.4 (2.8) g to 10.8 (3.5) g (P<0.001). The mean (SD) vitamin D level increased from baseline value of 16.0 (5.8) ng/mL to 23.4 (6.6) ng/mL (P<0.001). The change in serum osteocalcin and spot urine DPD/creatinine ratio were not significant (P=0.062). Oral vitamin D and calcium supplementation increases bone mineral content in children with thalassemia.

Diversity of activity participation determines bone mineral content in the lower limbs of pre-pubertal children with developmental coordination disorder.

Limited activity participation in children with developmental coordination disorder (DCD) may have a negative impact on bone mineral accrual. The objectives of this study were to compare bone mineralization and activity participation patterns of pre-pubertal children with DCD and those with typical development, and to determine the association between activity participation patterns and bone mineralization in children with DCD. Fifty-two children with DCD (mean age = 7.51years) and 61 children with typical development (mean age = 7.22years) participated in the study. Appendicular and total body (less head) bone mineral content (BMC) and bone mineral density (BMD) were evaluated by a whole-body dual-energy X-ray absorptiometry scan. Activity participation patterns were assessed using the Children's Assessment of Participation and Enjoyment (CAPE) questionnaire. Children with DCD had lower appendicular and total body BMCs and BMDs than children with typical development overall (p < 0.05). They also had lower CAPE total activity and physical activity diversity scores (p < 0.05). After accounting for the effects of age, sex, height, lean mass, and fat mass, the total activity diversity score remained independently associated with leg BMC in children with DCD, explaining 5.1% of the variance (p = 0.030). However, the physical activity diversity score was no longer associated with leg BMC (p = 0.090). Diversity of activity participation and bone mineralization were lower in pre-pubertal children with DCD. Decreased total activity participation diversity was a contributing factor to lower BMC in the legs of children with DCD.

Muscle/Lean Mass Measurement: Comparison between Methods and Correlation with Muscle Function

Children and adolescents living with HIV have low bone mass for age. There are reliable and accurate methods for evaluation of bone mass, however, alternative methods are necessary, especially, for application in limited-resource scenarios. Anthropometry is a noninvasive and low cost method that can predict bone mass in healthy youths. The aim of the study was to develop predictive equations for bone mineral content and bone mineral density in children and adolescents living with HIV based on anthropometric variables. Forty-eight children and adolescents of both sexes (24 females) from 7 to 17 years, living in greater Florianopolis area, Santa Catarina, Brazil, who were under clinical follow-up at “Hospital Infantil Joana de Gusmão”, participated in the study. Dual-energy X-ray absorptiometry was used to evaluate whole-body bone mineral content (BMC) and areal bone mineral density (aBMD). Height, body weight, bone diameters, arm circumference, and triceps skinfold were measured and the body mass index and arm muscle area were calculated. Multiple regression models were fitted to predict BMC and aBMD, using backward selection (p ≥ 0.05). Two predictive models with high R2 values (84%–94%) were developed. Model 1 to estimate aBMD [Y = −0.1450124 + (height × 0.0033807) + (age × 0.0146381) + (body mass index × 0.0158838) + (skin color × 0.0421068)], and model 2 to estimate BMC [Y = 1095.1 + (body weight × 45.66973) + (age × 31.36516) + (arm circumference × −53.27204) + (femoral diameter × −9.594018)].The predictive models using anthropometry provided reliable estimates and can be useful to monitor aBMD and BMC in children and adolescents living with human immunodeficiency virus where limited resources are available.

Anthropometric adjustments are helpful in the interpretation of BMD and BMC Z-scores of pediatric patients with Prader-Willi syndrome.

Bone mineral density (BMD) is decreased in patients with Prader-Willi syndrome (PWS). Because of largely abnormal body height and weight, traditional BMD Z-scores may not provide accurate information in this patient group. The goal of the study was to assess a cohort of individuals with PWS and characterize the development of low bone density based on two adjustment models applied to a dataset of BMD and bone mineral content (BMC) from dual-energy X-ray absorptiometry (DXA) measurements. Fifty-four individuals, aged 5-20years with genetically confirmed PWS, underwent DXA scans of spine and hip. Thirty-one of them also underwent total body scans. Standard Z-scores were calculated for BMD and BMC of spine and total hip based on race, sex, and age for all patients, as well as of whole body and whole-body less head for those patients with total-body scans. Additional Z-scores were generated based on anthropometric adjustments using weight, height, and percentage body fat and a second model using only weight and height in addition to race, sex, and age. As many PWS patients have abnormal anthropometrics, addition of explanatory variables weight, height, and fat resulted in different bone classifications for many patients. Thus, 25-70% of overweight patients, previously diagnosed as normal, were subsequently diagnosed as below normal, and 40-60% of patients with below-normal body height changed from below normal to normal depending on bone parameter. This is the first study to include anthropometric adjustments into the interpretation of BMD and BMC in children and adolescents with PWS. This enables physicians to get a more accurate diagnosis of normal versus abnormal BMD and BMC and allows for early and effective intervention.

Does Exercise Influence Pediatric Bone? A Systematic Review.

Periods of growth are thought to be the best time to increase bone mineral content, bone area, and areal bone mineral density (aBMD) through increased loading owing to high rates of bone modeling and remodeling. However, questions remain regarding whether a benefit of exercise is seen at all bone sites, is dependent on pubertal status or sex of the child, or whether other factors such as diet modify the response to exercise. We asked: (1) Does bone-loading exercise in childhood consistently increase bone mineral content, bone area, or aBMD? (2) Do effects of exercise differ depending on pubertal status or sex? (3) Does calcium intake modify the bone response to exercise? A literature search identified 22 unique trials for inclusion in this meta-analysis of the effect of exercise on bone changes by bone site, pubertal status, and sex. Sample sizes ranged from 16 to 410 subjects 3 to 18 years old with length of intervention ranging from 3 to 36 months. Fifteen of 22 trials were randomized (child randomized in nine, classroom/school randomized in six) and seven were observational trials. Ten trials were Level 2 and 11 were Level 3 based on the Oxford Centre for Evidence-Based Medicine criteria. Random effects models tested the difference (intervention mean effect-control mean effect) in percent change in bone mineral content, bone area, and aBMD. Meta-regression was used to identify sources of heterogeneity and funnel plots were used to assess publication bias. Children assigned to exercise had greater mean percent changes in bone mineral content and aBMD than children assigned to the control groups. Mean differences (95% CI) in bone mineral content percent change between intervention and control groups at total body (0.8; 95% CI, 0.3-1.3; p = 0.003), femoral neck (1.5; 95% CI, 0.5-2.5; p = 0.003), and spine (1.7; 95% CI, 0.4-3.1; p = 0.01) were significant with no differences in bone area (all p > 0.05). There were greater percent changes in aBMD in intervention than control groups at the femoral neck (0.6; 95% CI, 0.2-1.1; p = 0.006) and spine (1.2; 95% CI, 0.6-1.8; p < 0.001). Benefit of exercise was limited to children who were prepubertal (bone mineral content: total body [0.9; 95% CI, 0.2-1.7; p = 0.01], femoral neck [1.8; 95% CI, 0.0-3.5; p = 0.047], spine [3.7; 95% CI, 0.8-6.6; p = 0.01], and aBMD: femoral neck [0.6; 95% CI, -0.1-1.2; p = 0.07], spine [1.5; 95% CI, 0.7-2.3; p < 0.001]), with no differences among children who were pubertal (all p > 0.05). Changes in aBMD did not differ by sex (all p > 0.05), although the number of studies providing male-specific results was small (six of 22 eligible studies included boys). There was significant heterogeneity in bone mineral content and bone area for which a source could not be identified. Heterogeneity in spine aBMD was reduced by including calcium intake and intervention length as covariates. Three trials designed to determine whether calcium intake modified the bone response to exercise all reported a greater effect of exercise on leg bone mineral content in children randomized to receive supplemental calcium than those receiving placebo. Exercise interventions during childhood led to 0.6% to 1.7% greater annual increase in bone accrual, with effects predominantly among children who were prepubertal. If this effect were to persist into adulthood, it would have substantial implications for osteoporosis prevention. It is important to identify sources of heterogeneity among studies to determine factors that might influence the bone response to increased exercise during growth. Level II, therapeutic study.

Prediction of Areal Bone Mineral Density and Bone Mineral Content in Children and Adolescents Living With HIV Based on Anthropometric Variables

Children and adolescents living with HIV have low bone mass for age. There are reliable and accurate methods for evaluation of bone mass, however, alternative methods are necessary, especially, for application in limited-resource scenarios. Anthropometry is a noninvasive and low cost method that can predict bone mass in healthy youths. The aim of the study was to develop predictive equations for bone mineral content and bone mineral density in children and adolescents living with HIV based on anthropometric variables. Forty-eight children and adolescents of both sexes (24 females) from 7 to 17 years, living in greater Florianopolis area, Santa Catarina, Brazil, who were under clinical follow-up at “Hospital Infantil Joana de Gusmão”, participated in the study. Dual-energy X-ray absorptiometry was used to evaluate whole-body bone mineral content (BMC) and areal bone mineral density (aBMD). Height, body weight, bone diameters, arm circumference, and triceps skinfold were measured and the body mass index and arm muscle area were calculated. Multiple regression models were fitted to predict BMC and aBMD, using backward selection (p ≥ 0.05). Two predictive models with high R2 values (84%–94%) were developed. Model 1 to estimate aBMD [Y = −0.1450124 + (height × 0.0033807) + (age × 0.0146381) + (body mass index × 0.0158838) + (skin color × 0.0421068)], and model 2 to estimate BMC [Y = 1095.1 + (body weight × 45.66973) + (age × 31.36516) + (arm circumference × −53.27204) + (femoral diameter × −9.594018)].The predictive models using anthropometry provided reliable estimates and can be useful to monitor aBMD and BMC in children and adolescents living with human immunodeficiency virus where limited resources are available.

Reduced Bone Mass in 7-Year-Old Children with Asymptomatic Idiopathic Hypercalciuria

Background: Idiopathic hypercalciuria (IHC), i.e. an elevated urinary calcium excretion without concomitant hypercalcemia, is a common disorder in children and can have a range of urinary clinical presentations and decreased bone mineral density (BMD). Aim: To assess the effect of IHC on bone mineral content in children without urological symptoms. Methods: Calcium excretion, BMD (by dual-energy X-ray absorptiometry), and anthropometry were assessed in 175 seven-year-old children who were classified as IHC or controls. Calcium intake and physical activity were measured as confounding factors. Results: The prevalence of IHC was 17.7%. Both groups (controls and IHC) showed similar baseline characteristics in terms of their anthropometry, gender distribution, and protein and calcium dietary intakes as well as physical activity scores. Urinary calciuria was independent of the calcium dietary intake and anthropometry. BMD correlated with anthropometry and physical activity but not with calcium dietary intake. IHC children had lower whole-body BMD z-scores compared to controls. The role of IHC in reducing the whole-body BMD z-score was still significant even when anthropometry, physical activity, and calcium intake were included as confounders in multivariate analyses. Conclusions: The prevalence of IHC in this population of 7-year-old children was about 17%. IHC diagnosis was associated with lower BMD z-scores and osteopenia in 22% of them.

Objectively measured physical activity predicts hip and spine bone mineral content in children and adolescents ages 5-15 years: iowa bone development study.

This study examined the association between physical activity (PA) and bone mineral content (BMC; gram) from middle childhood to middle adolescence and compared the impact of vigorous-intensity PA (VPA) over moderate- to vigorous-intensity PA (MVPA). Participants from the Iowa bone development study were examined at ages 5, 8, 11, 13, and 15 years (n = 369, 449, 452, 410, and 307, respectively). MVPA and VPA (minutes per day) were measured using ActiGraph accelerometers. Anthropometry was used to measure body size and somatic maturity. Spine BMC and hip BMC were measured via dual-energy x-ray absorptiometry. Sex-specific multi-level linear models were fit for spine BMC and hip BMC, adjusted for weight (kilogram), height (centimeter), linear age (year), non-linear age (year2), and maturity (pre peak height velocity vs. at/post peak height velocity). The interaction effects of PA × maturity and PA × age were tested. We also examined differences in spine BMC and hip BMC between the least (10th percentile) and most (90th percentile) active participants at each examination period. Results indicated that PA added to prediction of BMC throughout the 10-year follow-up, except MVPA, did not predict spine BMC in females. Maturity and age neither modify the PA effect for males nor females. At age 5, the males at the 90th percentile for VPA had 8.5% more hip BMC than males in the 10th percentile for VPA. At age 15, this difference was 2.0%. Females at age 5 in the 90th percentile for VPA had 6.1% more hip BMC than those in the 10th percentile for VPA. The age 15 difference was 1.8%. VPA was associated with BMC at weight-bearing skeletal sites from childhood to adolescence, and the effect was not modified by maturity or age. Our findings indicate the importance of early and sustained interventions that focus on VPA. Approaches focused on MVPA may be inadequate for optimal bone health, particularly for females.

Greater lean tissue and skeletal muscle mass are associated with higher bone mineral content in children

BackgroundTo compare the relationship of skeletal muscle mass with bone mineral content in an ethnically diverse group of 6 to 18 year old boys and girls.Methods175 healthy children (103 boys; 72 girls) had assessments of body mass, height, and Tanner stage. Whole body bone mineral content, non-bone lean body mass (nbLBM), skeletal muscle mass, and fat mass were assessed using dual-energy X-ray absorptiometry (DXA). Muscle mass was estimated from an equation using appendicular lean soft tissue measured by DXA, weight and height. Estimates of skeletal muscle mass and adipose tissue were also assessed by whole body multi-slice magnetic resonance imaging (MRI). Linear regression was used to determine whether skeletal muscle mass assessed by DXA or by MRI were better predictors of bone mineral content compared with nbLBM after adjusting for sex, age, race or ethnicity, and Tanner stage.ResultsGreater skeletal muscle mass was associated with greater bone mineral content (p < 0.001). The skeletal muscle mass assessed by MRI provided a better fitting regression model (determined by R2 statistic) compared with assessment by DXA for predicting bone mineral content. The proportion of skeletal muscle mass in nbLBM was significantly associated with greater bone mineral content adjusted for total nbLBM.ConclusionsThis study is among the first to describe and compare the relationship of skeletal muscle to bone using both MRI and DXA estimates. The results demonstrate that the use of MRI provides a modestly better fitting model for the relationship of skeletal muscle to bone compared with DXA. Skeletal muscle had an impact on bone mineral content independent of total non-bone lean body mass. In addition, Hispanics had greater bone mineral content compared to other race and ethnic groups after adjusting for sex, age, adipose tissue, skeletal muscle mass, and height.

Deficits in Bone Mineral Content in Children and Adolescents With Cystic Fibrosis Are Related to Height Deficits

Despite reports of decreased bone density, children with mild to moderate cystic fibrosis (CF)–associated pulmonary disease do not have increased fracture rates. Short stature and delayed puberty complicate interpretations of bone mineral status in many children with chronic diseases. This study sought to characterize bone mineral content (BMC) in children with CF and determine its relationship to growth, body composition, and disease severity. Dual-energy X-ray absorptiometry measurements of whole body BMC (WB-BMC), spine BMC (Sp-BMC), and lean body mass (LBM) were converted to Z-scores in 82 CF and 322 healthy children. Effects of growth, body composition, and CF-disease characteristics on BMC were determined using linear regression. Children with CF had lower weight, height (HT), BMI, and LBM-Z. Females with CF had lower ( p < 0.001) WB-BMC-Z (−1.1 ± 1.1) and Sp-BMC-Z (−0.9 ± 1.1) than controls. Following adjustment for height standard deviation score (HT-Z), deficits were absent. Males with CF had lower ( p < 0.001) WB-BMC-Z (−1.3 ± 0.9) and Sp-BMC-Z (−0.9 ± 1.3). Following adjustment for HT-Z, WB-BMC-Z deficits were attenuated and Sp-BMC-Z deficits absent. HT-Z, LBM-Z, and pulmonary function had independent effects on WB-BMC-Z and Sp-BMC-Z. BMC deficits are related to altered body size, reduced LBM, and pulmonary function in children with CF. Interventions targeting improved growth, muscle mass, and pulmonary function may benefit bone health in CF.

Impact of dairy products and dietary calcium on bone-mineral content in children: Results of a meta-analysis

Objective Although calcium is essential for maintaining bone health in children, the optimum dietary intake of calcium in this age group, particularly in the form of dairy foods, is not well defined. A meta-analysis was conducted to examine the impact of dietary calcium/dairy supplementation on bone mineral content in this age group. Methods Data were pooled from randomized controlled intervention trials and observational studies using previously described methods. The outcome of interest was a summary mean difference bone mineral content. Sensitivity analyses were employed to evaluate any observed statistical heterogeneity and to examine the influence of specific study characteristics on the summary estimate of effect. Results Initially combining data from twenty-one randomized controlled trials (RCTs) using total body bone mineral content (TB-BMC) as the outcome of interest, yielded a non-statistically significant increase in TB-BMC of 2 g (supplemented versus controls). These data demonstrated substantial statistical heterogeneity with sensitivity analyses revealing that among study subjects with normal or near normal baseline dietary calcium/dairy intakes, supplemental dairy/calcium showed little impact on bone mineral content. Sensitivity analyses suggested that baseline calcium intake could potentially account for the statistical heterogeneity. Pooling the three reports utilizing low intake subjects yielded a statistically significant summary mean BMC of 49 g (24.0–76–6). Pooling two RCTs using calcium/dairy supplement plus vitamin D was also associated with an increase in lumbar spine BMC of, on average, 35 g (− 6.8–41.8). The lack of data using BMC measurements at other anatomic sites as well as sparse data from non-randomized studies, precluded further statistical pooling. Conclusion Increased dietary calcium/dairy products, with and without vitamin D, significantly increases total body and lumbar spine BMC in children with low base-line intakes.

Impact of dairy products and dietary calcium on bone mineral content in children: Results of a meta‐analysis

Objective: Although calcium is essential for maintaining bone health in children, the optimum dietary intake of calcium in this age group, particularly in the form of dairy foods, is a matter of debate. A meta‐analysis was conducted to examine the impact of dietary calcium/dairy supplementation on bone mineral content in this age group.Methods: Data were pooled from randomized controlled intervention trials and observational studies using previously described methods. The outcome of interest was a summary mean difference bone mineral content.Results: Combining data from twenty‐one randomized controlled trials (RCTs) using total body bone mineral content (TB‐BMC) as the outcome of interest, yielded a non‐statistically significant increase in TB‐BMC of 2 grams. These data demonstrated substantial statistical heterogeneity with sensitivity analyses revealing that among study subjects with normal or near normal baseline dietary calcium/dairy intakes, supplemental dairy/calcium showed little impact on bone mineral content. Sensitivity analyses suggested that baseline calcium intake could potentially account for the statistical heterogeneity. Pooling the three reports utilizing low intake subjects yielded a statistically significant summary mean BMC of 49 grams (24.0–76‐6). Pooling two RCTs using calcium/dairy supplement plus vitamin D was also associated with an increase in lumbar spine BMC of, on average, 35g (−6.8–41.8).Conclusion: Increased dietary calcium/dairy products, with and without vitamin D, significantly increases total body and lumbar spine BMC in children. Among children with “high baseline intakes” supplemental calcium/dairy products had little effect on TB‐BMC.