Dual effect of adipose tissue on bone health during growth

Linear and non-linear relationships between body fat mass distribution and bone mineral density in adults: The NHANES, 2011-2018

OBJECTIVE

The relationship between body fat mass and bone mineral density (BMD) remains controversial. This research aimed to explore the linear or non-linear relationship between body fat mass and BMD among adults in the United States.

METHODS

This cross-sectional study identified adults aged 18 years or older in the National Health and Nutrition Examination Survey from 2011 to 2018. After adjusting for covariates, linear relationships between body fat mass and BMD in different genders were tested by generalized linear models, and potential non-linear relationships were explored by generalized additive models and piecewise linear regression models.

RESULTS

The research included 4691 (57.9% of the total sample) males and 3417 (42.1% the of total sample) females. In both males and females, we found a negative association between android or total body fat mass and lumbar spine BMD and a positive association between appendicular, android, gynoid, or total body fat mass and whole body BMD (all P < 0.05). The relationships between body fat mass in all regions and lumbar spine BMD were U-shaped in males and inverted U-shaped in females (all Pnon-linear < 0.05). Inverted U-shaped relationships existed between body fat mass in all regions and whole body BMD in females (all Pnon-linear < 0.05).

CONCLUSIONS

Body fat mass was negatively and linearly associated with lumbar spine BMD, but positively associated with whole body BMD. Body fat mass had a U-shaped relationship with lumbar spine BMD in males and an inverted U-shaped association with lumbar spine and whole body BMD in females.

A systematic review and meta-analysis of pediatric normative peripheral quantitative computed tomography data

BACKGROUND

Peripheral-quantitative computed tomography (pQCT) provides an intriguing diagnostic alternative to dual-energy X-ray absorptiometry (DXA) since it can measure 3D bone geometry and differentiate between the cortical and trabecular bone compartments.

OBJECTIVE

To investigate and summarize the methods of pQCT image acquisition of in children, adolescents and/or young adults (up to age 20) and to aggregate the published normative pQCT data.

EVIDENCE ACQUISITION

A literature search was conducted in MEDLINE and EMBASE from 1947 to December 2020. Quality of the included articles was assessed using Standards for Reporting of Diagnostic Accuracy (STARD) scoring system and United States Preventative Services Task Force (USPSTF) Study Design Categorization. Seven articles, encompassing a total of 2134 participants, were aggregated in the meta-analysis. Due to dissimilar age groups and scan sites, only seven pQCT parameters of the 4% radius, 4% tibia and 38% tibia were analyzed in this meta-analysis.

EVIDENCE SYNTHESIS

The overall fixed-effect estimates of trabecular vBMD of the 4% radius were: 207.16 (201.46, 212.86), mg/cm3 in 8 to 9 year-old girls, 210.42 (201.91, 218.93)in 10 to 12 year-old girls, 226.99 (222.45, 231.54) in 12 to 13 year-old girls, 259.97 (254.85, 265.10) in 12 to 13 year-old boys and 171.55 (163.41,179.69) in 16 to 18 year-old girls. 21 of 54 (38.9%) primary papers received a 'good' STARD quality of reporting score (<90 and 70 ≥ %) (mean STARD score of all articles = 69.4%). The primary articles of this review had a 'good' level USPSTF study design categorization. However, most of the normative data in these articles were non-comparable and non-aggregable due to a lack of standardization of reference lines, acquisition parameters and/or age at acquisition.

CONCLUSION

There is not sufficient evidence to suggest that pQCT is appropriately suited for use in the pediatric clinical setting. Normative pediatric data must be systematically derived for pQCT should it ever be a modality that is used outside of research.

CLINICAL IMPACT

We demonstrate the need for normative pQCT reference data and for clinical guidelines that standardize pediatric acquisition parameters and delineate its use in pediatric settings.

Association between Body Composition and Bone Mineral Density in Children and Adolescents: A Systematic Review and Meta-Analysis

Background: Bone mass acquisition during growth is a major determinant of the risk of developing osteoporosis later in life. Body composition is an anthropometric determinant of bone mineral density (BMD) and significantly influences its development during childhood and adolescence. Objective: This study aimed to systematically examine the association between body composition and bone mineral density in children and adolescents. Methods: Observational studies addressing this association were identified from PubMed (MEDLINE), Embase, Scopus and the Cochrane Library (up to January 2021). The study populations consisted of healthy children and adolescents. The DerSimonian and Laird method was used to compute pooled estimates of effect size and the respective 95% confidence intervals for upper limbs, femoral neck (FN), lumbar spine (LS) and total body, respectively. Subgroup analyses were further performed based on age, sex and ethnicity. Results: Thirty-one published studies were eligible for inclusion in this systematic review and meta-analysis, including three longitudinal studies. The combined population from all the studies amounted to 21,393 (11,205 males and 10,188 females). The pooled estimates of the correlation coefficients for lean mass (LM) and BMD ranged from 0.53 to 0.74 (p < 0.050), and the pooled regression coefficients ranged from 0.23 to 0.79 for FN, LS and total body (p < 0.050). For fat mass (FM), the pooled correlation coefficients ranged from 0.10 to 0.50 (p < 0.050) and the pooled regression coefficient was only significant for FN BMD with a weak strength (pooled β = 0.07, p < 0.050). The pooled regression coefficients for body fat percentage (BF%) were between −0.54 and −0.04 (p < 0.050). The subgroup analysis revealed a stronger association in Asians than in Caucasians for LM and in males compared to females for BF% (p < 0.050). Conclusions: This systematic review and meta-analysis supports a positive association between LM and BMD. BF% appears to have a deleterious effect on bone acquisition in children and adolescents.

PREDICTORS OF BONE MINERAL DENSITY IN ADOLESCENTS WITH EXCESS WEIGHT

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

Associations of Weight-Adjusted Body Fat and Fat Distribution with Bone Mineral Density in Chinese Children Aged 6-10 Years

Although obesity is considered osteoprotective, the effects of body fat and fat distribution on bone tissue after adjusting for the effects of body weight remain uncertain. This study evaluated the relationships between fat mass, fat distribution, and bone mineral status beyond its weight-bearing effect. We recruited 466 children aged 6–10 years in China. Dual-energy X-ray absorptiometry was used to determine the bone mineral density (BMD) and bone mineral content (BMC) in the total body and total body less head (TBLH), as well as the fat mass (FM) and percentage fat mass (%FM) of the total and segmental body. Weight-adjusted measures of FM and %FM were derived using the residual method. After adjusting for the effects of covariates, we observed statistically significant, dose-dependent negative relationships between the TBLH·BMD/BMC and various weight-adjusted measures of body fat (p for trend: <0.001–0.038). For each standard deviation increment in the weight-adjusted total body, TBLH, trunk and limbs, the size-adjusted BMC decreased approximately 9.44, 9.28, 8.13, and 6.65 g in boys, respectively, and by approximately 13.74, 13.71, 7.84, and 12.95 g in girls, respectively. Significant inverse associations between FM accumulation in the total body and most body parts with the BMD/BMC were observed in both boys and girls after adjusting for weight and potential confounders.

Effects of Laparoscopic Sleeve Gastrectomy on Bone Mineral Density and Bone Metabolism in Chinese Patients with Obesity

OBJECTIVE

Laparoscopic sleeve gastrectomy (LSG) is one of the most effective therapies to treat obesity. Due to a lack of longitudinal research, we explored the changes in BMD and bone metabolism in Chinese patients with obesity before and after LSG.

MATERIALS AND METHODS

A total of 49 obese Chinese patients with obesity were recruited from the Second Xiangya Hospital of Central South University. All patients underwent LSG, and the metabolic indicators were evaluated, including the serum osteocalcin (OC), total-terminal propeptide of type I procollagen (TPINP) and carboxy terminal telopeptide of collagen type I (CTX) levels at baseline and 2, 6 and 12 months postoperatively. Dual energy X-ray absorptiometry (DEXA) was used to measure body composition and BMD before and 12 months after LSG.

RESULTS

The body mass index (BMI) significantly decreased at 12 months postoperatively, and no patients developed osteoporosis. The BMD of femoral neck and total hip significantly decreased from the baseline to 12 months postoperatively, while the BMD of lumbar spine did not change significantly. The OC, TPINP and CTX levels significantly increased at 12 months postoperatively. The excess BMI loss (EBMIL) was positively related while the reduction in visceral adipose tissue (VAT) mass was negatively related to the decreases in BMD of the femoral neck and total hip at 12 months postoperatively. The increase in OC was negatively correlated with the decrease in BMD of the femoral neck, while the increase in TPINP was positively correlated with the decrease in BMD of total hip.

CONCLUSION

Based on the 12-month follow-up results, the BMD of the femoral neck and total hip was decreased in Chinese patients with obesity after LSG, while bone remodelling was active. This finding suggested that weight loss, a decrease in the VAT mass and an increase in bone remodelling may be correlated with a reduction in BMD.

Severe Phenotype of APECED (APS1) Increases Risk for Structural Bone Alterations

Objective: Immunological abnormalities, the resulting endocrinopathies and their treatments may impact bone health in patients with autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED, APS1). The aim of the present study was to describe skeletal characteristics in patients with APECED and the prevalence and risk factors of compromised bone health. Patients and methods: We performed a cross-sectional study on 44 patients (27 females) with APECED and 82 age-, gender- and ethnicity-matched control subjects (54 females). We determined the prevalence of osteoporosis by dual-energy X-ray absorptiometry and skeletal characteristics by peripheral quantitative computed tomography at radius and tibia. Results: Patients were examined at the median age of 37.8 years (range, 7.0-70.1). Dual-energy X-ray absorptiometry indicated osteoporosis in four adult patients (9%); radiographs showed vertebral fractures in three patients. The prevalence of multiple non-spinal fractures was higher in patients than in controls. On peripheral quantitative computed tomography, bone characteristics at distal and proximal radius did not differ between the groups. At distal tibia, patients had lower total (p = 0.009) and trabecular (p = 0.033) volumetric bone mineral density. At the proximal tibia, patients had lower cortical thickness (p < 0.001) than controls. Severity of APECED phenotype influenced both radial and tibial characteristics: cortical thickness and total and trabecular volumetric bone mineral density were lower in patients with ≥7 disease manifestations as compared with more mildly affected patients, whose values were similar to controls. Conclusions: APECED associated with bone structural alterations, especially in patients with a high number of disease manifestations. This may increase the risk of fractures with aging, but symptomatic osteoporosis was rare.

Determinants for low bone mineral density in pre-school children: a matched case-control study in Wuhan, China

Introduction Reduced bone mass will increase bone fragility and risk of fractures. Thus, it is better to note its determinants as early as possible. Objective This study aimed to find and determine the determinants for low bone mineral density (BMD) in pre-school children. Methods Between November 2014 and April 2015, a matched case-control study was performed to detect information on growth and development condition and consumption frequency of products of cases with low BMD and controls with normal BMD. Anthropometric data measurement and blood tests were conducted. Besides, the questionnaires concerning the mentioned information were completed to get relevant determinants. A paired t-test, the McNemar test and univariate and multiple conditional logistic regression models were used to explore the association between these factors and low BMD. Results In total, 88 (28 boys, 60 girls) incident cases (4.15 ± 0.78 years) of low BMD and 88 sex- and age-matched (±2 months) controls (4.16 ± 0.80 years) of normal BMD were enrolled. The results of multiple conditional logistic regression analysis indicated that if children had larger chest circumference (odds ratio [OR] = 0.763), longer duration of breastfeeding (OR = 0.899) and lower frequency of eating snacks (OR = 0.439), the risk of low BMD would decrease. Conclusions Our findings suggest that pre-school children with an association of larger chest circumference, longer duration of breastfeeding and lower frequency of eating snacks could have lower risk for low BMD. Intended measures to strengthen those protective factors could be effective in reducing the cases of low BMD.

Progress in active compounds effective on ulcerative colitis from Chinese medicines

Ulcerative colitis (UC), a chronic inflammatory disease affecting the colon, has a rising incidence worldwide. The known pathogenesis is multifactorial and involves genetic predisposition, epithelial barrier defects, dysregulated immune responses, and environmental factors. Nowadays, the drugs for UC include 5-aminosalicylic acid, steroids, and immunosuppressants. Long-term use of these drugs, however, may cause several side effects, such as hepatic and renal toxicity, drug resistance and allergic reactions. Moreover, the use of traditional Chinese medicine (TCM) in the treatment of UC shows significantly positive effects, low recurrence rate, few side effects and other obvious advantages. This paper summarizes several kinds of active compounds used in the experimental research of anti-UC effects extracted from TCM, mainly including flavonoids, acids, terpenoids, phenols, alkaloids, quinones, and bile acids from some animal medicines. It is found that the anti-UC activities are mainly focused on targeting inflammation or oxidative stress, which is associated with increasing the levels of anti-inflammatory cytokine (IL-4, IL-10, SOD), suppressing the levels of pro-inflammatory cytokines (TNF-α, IL-1β, IL-6, IL-8, IL-23, NF-κB, NO), reducing the activity of MPO, MDA, IFN-γ, and iNOS. This review may offer valuable reference for UC-related studies on the compounds from natural medicines.

How Is Adolescent Bone Mass and Density Influenced by Early Life Body Size and Growth? The Tromsø Study: Fit Futures-A Longitudinal Cohort Study From Norway

The effect of birth weight and childhood body mass index (BMI) on adolescents’ bone parameters is not established. The aim of this longitudinal, population‐based study was to investigate the association of birth weight, childhood BMI, and growth, with adolescent bone mass and bone density in a sample of 633 adolescents (48% girls) from The Tromsø Study: Fit Futures. This population‐based cohort study was conducted in 2010–2011 and 2012–2013 in Tromsø, Norway. Bone mineral content (BMC) and areal BMD (aBMD) were measured at total hip (TH) and total body (TB) by dual‐energy X‐ray absorptiometry (DXA) and converted to internal Z‐scores. Birth weight and childhood anthropometric measurements were retrospectively obtained from the Medical Birth Registry of Norway and childhood health records. Associations between birth weight, BMI, and growth were evaluated by fitting linear mixed models with repeated measures of BMC and aBMD at ages 15 to 17 and 18 to 20 years as the outcome. In crude analysis, a significant positive association (p < 0.05) with TB BMC was observed per 1 SD score increase in birth weight, observed in both sexes. Higher rate of length growth, conditioned on earlier size, from birth to age 2.5 years, and higher rate of weight gain from ages 6.0 to 16.5 years, conditioned on earlier size and concurrent height growth, revealed stronger associations with bone accrual at ages 15 to 20 years compared with other ages. Compared with being normal weight, overweight/obesity at age 16.5 years was associated with higher aBMD Z‐scores: β coefficient (95% confidence interval [CI]) of 0.78 (0.53, 1.03) and 1.08 (0.85, 1.31) in girls, 0.63 (0.42, 0.85) and 0.74 (0.54, 0.95) in boys at TH and TB, respectively. Similar associations were found for BMC. Being underweight was consistently negatively associated with bone parameters in adolescence. In conclusion, birth weight influences adolescent bone mass but less than later growth and BMI in childhood and adolescence. © 2018 The Authors. JBMR Plus Published by Wiley Periodicals, Inc. on behalf of the American Society for Bone and Mineral Research

Body fat mass, lean body mass and associated biomarkers as determinants of bone mineral density in children 6-8years of age - The Physical Activity and Nutrition in Children (PANIC) study

Lean body mass (LM) has been positively associated with bone mineral density (BMD) in children and adolescents, but the relationship between body fat mass (FM) and BMD remains controversial. Several biomarkers secreted by adipose tissue, skeletal muscle, or bone may affect bone metabolism and BMD. We investigated the associations of LM, FM, and such biomarkers with BMD in children. We studied a population sample of 472 prepubertal Finnish children (227 girls, 245 boys) aged 6-8years. We assessed BMD, LM, and FM using whole-body dual-energy x-ray absorptiometry and analysed several biomarkers from fasting blood samples. We studied the associations of LM, FM, and the biomarkers with BMD of the whole body excluding the head using linear regression analysis. LM (standardized regression coefficient β=0.708, p<0.001), FM (β=0.358, p<0.001), and irisin (β=0.079, p=0.048) were positive correlates for BMD adjusted for age, sex, and height in all children. These associations remained statistically significant after further adjustment for LM or FM. The positive associations of dehydroepiandrosterone sulphate (DHEAS), insulin, homeostatic model assessment for insulin resistance (HOMA-IR), leptin, free leptin index, and high-sensitivity C-reactive protein and the negative association of leptin receptor with BMD were explained by FM. The positive associations of DHEAS and HOMA-IR with BMD were also explained by LM. Serum 25-hydroxyvitamin D was a positive correlate for BMD adjusted for age, sex, and height and after further adjustment for FM but not for LM. LM and FM were positive correlates for BMD also in girls and boys separately. In girls, insulin, HOMA-IR, leptin, and free leptin index were positively and leptin receptor was negatively associated with BMD adjusted for age, height, and LM. After adjustment for age, height, and FM, none of the biomarkers was associated with BMD. In boys, leptin and free leptin index were positively and leptin receptor was negatively associated with BMD adjusted for age, height, and LM. After adjustment for age, height and FM, 25(OH)D was positively and IGF-1 and leptin were negatively associated with BMD. FM strongly modified the association between leptin and BMD. LM but also FM were strong, independent positive correlates for BMD in all children, girls, and boys. Irisin was positively and independently associated with BMD in all children. The associations of other biomarkers with BMD were explained by LM or FM.

Influence of adipose tissue mass on bone mass in an overweight or obese population: systematic review and meta-analysis

Context

The scientific literature shows conflicting evidence about the relationship between adiposity and bone mass in overweight and obese populations. The aim of this review was to quantify the correlation between adipose mass (absolute and relative) and bone mineral density (BMD) in overweight and obese populations. Three databases were searched electronically. In addition, reference lists of relevant articles were screened. A total of 16 studies, comprising 2587 participants and 75 correlation coefficients were selected for inclusion in the review. Data were extracted from each study using a standardized form. Multilevel modeling indicated opposing relationships between BMD and adiposity: absolute adiposity correlated positively, and relative adiposity negatively, with BMD. Sex and age were the primary moderators of these relationships. Strong evidence supported a negative relationship between relative adipose mass and BMD in men (R = -0.37; 95%CI, -0.57 to -0.12) and in those aged less than 25 years (R = -0.28; 95%CI, -0.45 to -0.08). To prevent bone loss in overweight and obese populations, nutrition- and exercise-based interventions that focus on a controlled reduction of adipose mass with concomitant preservation of lean mass are recommended. : PROSPERO no. CRD42015024313.

Bone Health is Maintained, While Fat Mass is Reduced in Pre-pubertal Children with Obesity Participating in a 1-Year Family-Centered Lifestyle Intervention

Diet and physical activity (PA) influence bone health in children. This study tested whether increasing milk and milk products and weight-bearing types of PA favorably changed bone outcomes assessed by dual-energy X-ray absorptiometry (DXA) and bone biomarkers in children with obesity participating in a 1-year family-centered lifestyle intervention. Children were randomized to one of three groups: Control (Ctrl; no intervention), Standard treatment (StnTx: two servings milk and milk products/day; meet PA guidelines plus weight-bearing PA three times/week), or Modified treatment (ModTx: four servings milk and milk products/day; meet PA guidelines plus daily weight-bearing PA). Baseline and 12-month measurements included DXA scans for whole body (WB), lumbar spine (LS), lumbar lateral spine (LLS), and ultra-distal (UD) ulna + radius for bone mineral content (BMC), areal bone mineral density (aBMD) and BMD z-scores. Fat mass index (FMI), fat-free mass index (FFMI), and biomarkers of bone metabolism were assessed. Seventy-eight children 6-8 years old were recruited (mean body mass index for-age z-score: 3.3 ± 1.2). Compared to baseline, all groups increased BMC of WB, LS, and LLS (p < 0.001), whereas only StnTx increased UD ulna + radius BMC at 12 months (p < 0.05). At 12 months, WB-BMD z-scores were significantly lower in Ctrl (p < 0.05), whereas WB and LLS aBMD increased in StnTx and ModTx (p < 0.001) but not in Ctrl. All groups increased FFMI (p < 0.001), while only Ctrl increased FMI (p < 0.001). Bone biomarkers did not change over time. Participating in a family-centered lifestyle intervention based on Canadian diet and PA guidelines maintained bone health in obese children.

Metabolic milieu associates with impaired skeletal characteristics in obesity

High leptin concentration, low-grade inflammation, and insulin resistance often coexist in obese subjects; this adverse metabolic milieu may be the main culprit for increased fracture risk and impaired bone quality seen in patients with type 2 diabetes. We examined the associations of leptin, hs (high sensitivity)- CRP and insulin resistance with bone turnover markers (BTMs) and bone characteristics in 55 young obese adults (median BMI 40 kg/m²) and 65 non-obese controls. Mean age of the subjects was 19.5 ± 2.5 years (mean ± SD). Concentrations of leptin, adiponectin, hs-CRP, MMP-8 and TIMP-1, fasting plasma glucose and insulin (to calculate HOMA), BTMs (BAP, P1NP, CTX-1, and TRAC5b) were measured. Bone characteristics were determined with pQCT at radius and tibia, and with DXA for central sites. Leptin, hs-CRP and HOMA correlated inversely with BTMs: the partial coefficients were 1.5–1.9 fold higher in males than in females. After adjusting for age, BMI, and other endocrine factors, leptin displayed an independent effect in males on radial bone mass (p = 0.019), tibial trabecular density (p = 0.025) and total hip BMD (p = 0.043), with lower densities in males with high leptin. In females, the model adjusting for age, BMI, and other endocrine factors, revealed that hs-CRP had independent effects on radial bone mass (p = 0.034) and lumbar spine BMD (p = 0.016), women with high hs-CRP having lower values. Partial correlations of adiponectin and TIMP-1 with bone characteristics were discrepant; MMP-8 showed no associations. In conclusion, in young obese adults and their controls, leptin, hs-CRP and HOMA associate inversely with BTMs and bone characteristics. Leptin appears to be the key independent effector in males, whereas hs-CRP displayed a predominant role in females.

Associations Between Body Composition and Bone Health in Children and Adolescents: A Systematic Review

More clarification on the associations between children's and adolescents' lean and fat mass (LM and FM) on the one hand and their bone health on the other hand is needed, given the rising prevalence of overweight and obesity in this population. This systematic literature review aimed to describe the current evidence on these associations. Data sources were Medline/PubMed, EMBASE, CINAHL and The Cochrane Library (up to November 2014). Search items included LM, FM, children and adolescents (0-18 years), bone health measured with dual-energy X-ray absorptiometry and peripheral quantitative computed tomography (pQCT) and search items concerning study design: observational and longitudinal studies. The study populations were healthy children and adolescents including obese children. Children with other diseases and clinical series of study subjects were excluded. Based on the studies included in this review (n = 19), there is a consensus that the contribution of LM to the variance of the different bone parameters is larger than the contribution of FM and that an increase in LM is associated with an increase in bone parameters. Most of the studies indicated that the increase in bone parameters seen in overweight and obese children and adolescents is due to an increase in LM and not to greater FM. The results on the association between body fat and bone parameters were contradictory and depended on children's age and sex. Still more data from studies with a longitudinal study design using (high resolution) pQCT and a representative sample are needed to get further insight in the associations between body fat and bone parameters in children, specifically concerning differences in sex, skeletal site and fat depots.

Maternal Dietary Vitamin D Does Not Program Systemic Inflammation and Bone Health in Adult Female Mice Fed an Obesogenic Diet

Obesity is associated with systemic inflammation and impaired bone health. Vitamin D regulates bone metabolism, and has anti-inflammatory properties and epigenetic effects. We showed that exposure to high dietary vitamin D during pregnancy and lactation beneficially programs serum concentration of lipopolysaccharide (LPS) and bone structure in male offspring fed an obesogenic diet. Here we assessed if this effect is also apparent in females. C57BL/6J dams were fed AIN93G diet with high (5000 IU/kg diet) or low (25 IU/kg diet) vitamin D during pregnancy and lactation. Post-weaning, female offspring remained on their respective vitamin D level or were switched and fed a high fat and sucrose diet (44.2% fat, 19.8% sucrose) until age seven months when glucose response, adiposity, serum LPS, and bone mineral, trabecular and cortical structure, and biomechanical strength properties of femur and vertebra were assessed. There was no evidence for a programming effect of vitamin D for any outcomes. However, females exposed to a high vitamin D diet post-weaning had higher bone mineral content (p = 0.037) and density (p = 0.015) of lumbar vertebra. This post-weaning benefit suggests that in females, bone mineral accrual but not bone structure is compromised with low vitamin D status in utero until weaning in an obesogenic context.

Skeletal Characteristics of WNT1 Osteoporosis in Children and Young Adults

WNT proteins comprise a 19-member glycoprotein family that act in several developmental and regenerative processes. In bone, WNT proteins regulate osteoblast differentiation and maintain bone health by activating the canonical WNT/β-catenin pathway. We reported a heterozygous missense mutation c.652T>G (p.C218G) in WNT1 exon 4 as the cause for severe early-onset, autosomal dominant osteoporosis. The initial study concerned a large Finnish family with 10 affected adults. Here we report clinical findings of the WNT1 osteoporosis in 8 children and young adults (median age 14 years; range 10 to 30 years) in two families, all with the p.C218G mutation in WNT1. Clinical assessments showed no apparent dysmorphia or features similar to typical osteogenesis imperfecta (OI). Biochemistry revealed no changes in parameters of calcium metabolism and bone turnover markers. Fracture frequencies varied, but all subjects had sustained at least one fracture and 4 had a pathological fracture history. Plain radiographs showed osteopenic appearance, loss in vertebral height, and thin diaphyses of the long bones. Bone densitometry showed the BMD to be below normal median in all subjects and the bone mass deficit seemed to be more severe in older participants. Bone histomorphometry revealed a low turnover osteoporosis in 2 subjects at ages 14 and 16 years. These findings are congruent with earlier findings in adult patients and indicate that WNT1 osteoporosis causes significant skeletal changes already in early childhood and impairs bone mass gain during pubertal years. Genetic testing of children or close relatives of affected individuals is recommended for appropriate preventive measures. © 2016 American Society for Bone and Mineral Research.

Longitudinal associations between bone and adipose tissue biochemical markers with bone mineralization in boys during puberty

Background

We investigated longitudinal relationships between the biochemical markers of bone and adipose tissue with bone mineral content (BMC), bone mineral density (BMD), moderate-to-vigorous physical activity (MVPA) and sedentary time (SED) in pubertal boys.

Methods

Ninety-six boys (11.9 ± 0.6 years old) were measured at baseline, after 12 and 24 months. Body composition (fat mass [FM], lean body mass [LBM]), and whole body (WB), lumbar spine (LS) and femoral neck (FN) BMD and BMC were assessed. Additionally, serum leptin, adiponectin, osteocalcin (OC) and C-terminal telopeptide of type I collagen (CTX) were measured.

Results

OC had a strong longitudinal inverse effect on changes in WB_BMD (p < 0.001) and LS_BMD (p = 0.021), while CTX had an inverse effect only on changes in FN_BMD (p = 0.011). Leptin had an inverse effect on changes in WB_BMC/WB_BMD (p = 0.001), FN_BMD (p = 0.002) and LS_BMD (p = 0.001). MVPA showed a longitudinal inverse effect on changes in leptin (p = 0.030), however no longitudinal effect of SED to biochemical markers of bone and adipose tissue was found.

Conclusions

Bone metabolism markers have negative effect on bone mineral accrual during puberty. Increases in MVPA affect leptin, suggesting a positive link of MVPA through leptin metabolism on increases in bone mineralization during puberty.

Bone Characteristics and Their Determinants in Adolescents and Young Adults with Early-Onset Severe Obesity

Childhood obesity is associated with compromised bone health. We studied bone characteristics and their determinants in obese young adults. The study included 68 subjects with early-onset severe obesity and 73 normal-weight controls. Data on physical activity (PA), diet and smoking were collected. Bone characteristics were measured using peripheral QCT. The obese and control subjects were similar in age (mean 19.6 ± 2.6 years) and height but BMIs differed (39.7 and 22.6 kg/m(2)). A clustering of unhealthy lifestyles was marked: Obese subjects reported less supervised PA in childhood, adolescence and currently (p < 0.03) and were more likely to smoke (p = 0.005), and had a lower healthy eating index (HEI) (p = 0.007) but similar alcohol consumption compared with controls. In obese women, all crude bone characteristics were higher than in controls; in men, the differences were smaller. Associations of lifestyle factors with bone characteristics were tested using partial correlations. Independently of BMI, supervised PA in adolescence and alcohol consumption were related positively to bone characteristics in both groups. HEI associated positively with bone characteristics only in controls, while smoking was a positive determinant of bone characteristics only in obese subjects. The multivariate model showed that the contribution of lifestyle factors to bone characteristics was minimal compared with BMI. Early-onset obesity is accompanied by poor dietary quality, sedentary lifestyle, and more frequent smoking, but the overall contribution of these lifestyle factors to bone strength is limited. Bone strength is more likely to be compromised in men and in unloaded bone sites in subjects with early-onset severe obesity. The impact of obesity-related endocrine changes on bone characteristics need to be evaluated in future studies.

Relative Importance of Lean and Fat Mass on Bone Mineral Density in Iranian Children and Adolescents

BACKGROUND

Body weight is made up of lean and fat mass and both are involved in growth and development. Impression of these two components in bone density accrual has been controversial.

OBJECTIVES

The aim of this study was to evaluate the relationship between fat and lean mass and bone density in Iranian children and adolescents.

PATIENTS AND METHODS

A cross-sectional study was performed on 472 subjects (235 girls, 237 boys) aged 9-18 years old in Fars Province. The participants' weight, height, waist circumference, stage of puberty, and level of physical activity were recorded. Bone Mineral Content (BMC), Bone Mineral Density (BMD), total body fat and lean mass were measured using dual-energy X-ray absorptiometry.

RESULTS

Results showed that 12.2% of boys and 12.3% of girls were overweight and 5.5% of boys and 4.7% of girls were obese. Obese individuals had greater total body BMD (0.96 ± 0.11) than normal-weight ones (0.86 ± 0.11) (P < 0.001). We found the greatest correlation between total body BMD and total body lean mass (R = 0.78. P < 0.001) and the least correlation with total body fat percentage (R = 0.03, P = 0.44). Total lean mass in more active boys was 38.1 ± 10.9 and in less active boys was 32.3 ± 11.0 (P < 0.001). The results of multiple regression analysis showed that age and total body lean mass were independent factors of BMD in growing children and adolescents.

CONCLUSIONS

These findings suggest that lean mass was the most important predictor of BMD in both genders. Physical activity appears to positively impact on lean mass and needs to be considered in physical education and health-enhancing programs in Iranian school children.

Longitudinal changes in lean mass predict pQCT measures of tibial geometry and mineralisation at 6-7 years

BACKGROUND

Studies in childhood suggest that both body composition and early postnatal growth are associated with bone mineral density (BMD). However, little is known of the relationships between longitudinal changes in fat (FM) and lean mass (LM) and bone development in pre-pubertal children. We therefore investigated these associations in a population-based mother-offspring cohort, the Southampton Women's Survey.

METHODS

Total FM and LM were assessed at birth and 6-7 years of age by dual-energy x-ray absorptiometry (DXA). At 6-7 years, total cross-sectional area (CSA) and trabecular volumetric BMD (vBMD) at the 4% site (metaphysis) of the tibia was assessed using peripheral quantitative computed tomography [pQCT (Stratec XCT-2000)]. Total CSA, cortical CSA, cortical vBMD and strength-strain index (SSI) were measured at the 38% site (diaphysis). FM, LM and bone parameters were adjusted for age and sex and standardised to create within-cohort z-scores. Change in LM (ΔLM) or FM (ΔFM) was represented by change in z-score from birth to 7 years old and conditioned on the birth measurement. Linear regression was used to explore the associations between ΔLM or ΔFM and standardised pQCT outcomes, before and after mutual adjustment and for linear growth. The β-coefficient represents SD change in outcome per unit SD change in predictor.

RESULTS

DXA at birth, in addition to both DXA and pQCT scans at 6-7 years, were available for 200 children (48.5% male). ΔLM adjusted for ΔFM was positively associated with tibial total CSA at both the 4% (β=0.57SD/SD, p<0.001) and 38% sites (β=0.53SD/SD, p<0.001), cortical CSA (β=0.48SD/SD, p<0.001) and trabecular vBMD (β=0.30SD/SD, p<0.001), but not with cortical vBMD. These relationships persisted after adjustment for linear growth. In contrast, ΔFM adjusted for ΔLM was only associated with 38% total and cortical CSA, which became non-significant after adjustment for linear growth.

CONCLUSION

In this study, gain in childhood LM was positively associated with bone size and trabecular vBMD at 6-7 years of age. In contrast, no relationships between change in FM and bone were observed, suggesting that muscle growth, rather than accrual of fat mass, may be a more important determinant of childhood bone development.

FGF23 gene variation and its association with phosphate homeostasis and bone mineral density in Finnish children and adolescents

Fibroblast growth factor 23 (FGF23), a bone-derived hormone, participates in the hormonal bone-parathyroid-kidney axis, which is modulated by PTH, 1,25-dihydroxyvitamin D, plasma phosphate (Pi), and diet. Inappropriately high serum FGF23, seen in certain genetic and acquired disorders, results in urinary phosphate wasting and impaired bone mineralization. This study investigated the impact of FGF23 gene variation on phosphate homeostasis and bone health. The study included 183 children and adolescents (110 girls) aged 7-19 years (median 13.2years). Urine and blood parameters of calcium and phosphate homeostasis were analyzed. Bone characteristics were quantified by DXA and peripheral quantitative computed tomography (pQCT). Genetic FGF23 variation was assessed by direct sequencing of coding exons and flanking intronic regions. Nine FGF23 polymorphisms were detected; three of them were common: rs3832879 (c.212-37insC), rs7955866 (c.716C>T, p.T239M) and rs11063112 (c.2185A>T). Four different haplotypes and six different diplotypes were observed among these three polymorphisms. The variations in FGF23 significantly associated with plasma PTH and urinary Pi excretion, even after adjusting for relevant covariates. FGF23 variations independently associated with total hip BMD Z-score, but not with other bone outcomes. In instrument analysis, genetic variance in FGF23 was considered a weak instrument as it only induced small variations in circulating FGF23, PTH and Pi concentrations (F statistic less than 10). The observed associations between FGF23 variations and circulating PTH, and Pi excretion and total hip BMD Z-scores suggest that FGF23 polymorphisms may play a role in mineral homeostasis and bone metabolism.

The Relation between Visceral and Subcutaneous Fat to Bone Mass among Egyptian Children and Adolescents

BACKGROUND: The relation between fat distribution and bone mass is still being debated in children and adolescents.AIM: To verify the influence of both visceral and subcutaneous fat on bone mass among Egyptian children and adolescents.SUBJECTS AND METHODS: The study involved 78 (38 boys and 40 girls) individuals from children (42) and adolescents (36), aged 8-17 years. They were divided into 2 age groups: children group (20 boys and 22 girls) aged 8-12 years and adolescent group (18 boys and 18 girls) aged 13-17 years. Anthropometric measurements, visceral and subcutaneous fat (measured by ultrasound), body composition, BMD and BMC (Measured by DXA), were attempted.RESULTS: Among children, significant positive correlations between visceral fat; in males; and subcutaneous fat; in females; with total BMC, BMD and its Z-score were revealed. After exclusion of age effect, the association between visceral fat in females with total BMD and its Z-score and lumbar BMD-Z-score became significant.  For adolescents, no correlation was observed between either visceral or subcutaneous fat with any parameter of bone mass.CONCLUSIONS: Visceral and subcutaneous fat had significant positive association with bone mass in children; males and females respectively. On the contrary such association disappeared during adolescence.

Muscle-bone and fat-bone interactions in regulating bone mass: do PTH and PTHrP play any role?

Metabolic bone disease occurs when there is a net loss in bone density. Osteoporosis, the most common metabolic bone disease, is a devastating problem and an increasingly major public health issue. A substantial body of evidence in the elderly population indicates that a relationship exists between the components of body weight and various measures of bone/mass, density, and function. Both muscle and fat contribute to the body's total weight and the intimate associations of muscle, fat, and bone are known. But the close functional interactions between muscle and bone or fat and bone are largely unidentified and have drawn much attention in recent years. Each of these tissues not only responds to afferent signals from traditional hormone systems and the central nervous systems but also secretes factors with important endocrine functions. Studies suggest that during growth, development, and aging, the relationship of muscle and fat with the skeleton possibly governs bone homeostasis and turnover. A better understanding of the endocrine function and the cellular and molecular mechanisms and pathways linking muscle or adipose tissues with bone anabolism and catabolism is a new avenue for novel pathways for anabolic drug discovery. These in turn will likely lead to more rational therapy toward increasingly prevalent disorders like osteoporosis. In this review, some of the recent works on the interaction of bone with muscle and fat are highlighted, and in so doing the role of parathyroid hormone (PTH), and PTH-related peptide (PTHrP) is surveyed.

High adiposity and serum leptin accompanied by altered bone turnover markers in severe juvenile idiopathic arthritis

OBJECTIVE

To evaluate interactions between skeleton and adipose tissue, and association of adipokines and bone turnover markers with disease-related factors in patients with severe juvenile idiopathic arthritis (JIA).

METHODS

Forty-nine patients (median age 14.8 yrs, median disease duration 10.2 yrs) with refractory polyarticular JIA and 89 sex-matched and age-matched healthy controls participated in the study. Study subjects underwent clinical examination, body composition assessment with dual-energy X-ray absorptiometry, and analyses for leptin, adiponectin, and bone turnover markers.

RESULTS

Patients with JIA were shorter and more often overweight (p = 0.001) or obese (p < 0.001) than controls. They had significantly higher serum leptin, even when adjusted for fat mass (p < 0.001), than did controls. Adiponectin did not differ between the groups. Concentration of carboxyterminal telopeptide of type I collagen was higher (p = 0.006) in patients. The inverse association between leptin and bone turnover markers disappeared in controls but was strengthened in patients when adjusted for fat mass. Leptin, adiponectin, or bone markers did not associate with variables of disease activity.

CONCLUSION

Patients with severe JIA had high adiposity accompanied by increased bone resorption. Their serum leptin was higher, even independently of fat mass. Leptin tended to associate inversely with bone turnover markers but did not associate with variables of disease activity.

Vitamin D binding protein genotype is associated with serum 25-hydroxyvitamin D and PTH concentrations, as well as bone health in children and adolescents in Finland

Vitamin D binding protein (DBP)/group-specific component (Gc), correlates positively with serum vitamin D metabolites, and phenotype influences serum 25-hydroxyvitamin D (S-25(OH)D) concentration. The protein isoform has been associated with decreased bone mineral density (BMD) and increased fracture risk. We examined the role of GC genotypes in S-25(OH)D status and BMD in 231 Finnish children and adolescents aged 7-19 yr. BMD was measured with DXA from lumbar spine (LS), total hip, and whole body, and for 175 subjects, radial volumetric BMD was measured with pQCT. Background characteristic and total dietary intakes of vitamin D and calcium were collected. The concentrations of 25(OH)D, parathyroid hormone (PTH), calcium and other markers of calcium homeostasis were determined from blood and urine. Genotyping was based on single-nucleotide polymorphism (rs4588) in the GC gene. The genotype distribution was: GC 1/1 68%, GC 1/2 26% and GC 2/2 6%. A significant difference emerged in 25(OH)D and PTH concentrations between the genotypes, (p = 0.001 and 0.028 respectively, ANCOVA). There was also a linear trend in: Gc 2/2 had the lowest 25(OH)D and PTH concentrations (p = 0.025 and 0.012, respectively). Total hip bone mineral content was associated with GC genotype (BMC) (p = 0.05, ANCOVA) in boys. In regression analysis, after adjusting for relevant covariates, GC genotype was associated with LS BMC and strength and strain index (SSI) Z-score in both genders, and LS BMD in boys. In conclusion, the present study demonstrates the association between GC genotypes and S-25(OH)D and PTH concentrations. The results show the influence of DBP genetic variation on bone mass accrual in adolescence.

Fat mass increase in 7-year-old children: more bone area but lower bone mineral density

The main aims of this study were, to evaluate what effect a change in fat mass (FM) and lean body mass (LBM) has on bone parameters over 2 years' time, in 7-year-old school children and to see what effect fitness had on bone parameters in these children. A repeated-measures design study was conducted where children born in 1999 from six elementary schools in Reykjavik, Iceland were measured twice. All children attending second grade in these six schools were invited to participate. Three hundred twenty-one children were invited, 211 underwent dual-energy X-ray absorptiometry (DXA) scans at the age of seven, and 164 (78 %) of the 211 had DXA scans again 2 years later. Increase in both FM and LBM was associated with increased total body bone mineral content (BMC) and bone area (BA). An increase in FM was more strongly positively associated with BA while an increase in LBM was more strongly associated with an increase in BMC. An increase in FM was negatively associated with change in bone mineral density (BMD), but an increase in LBM was positively associated with change in BMD. Fitness was positively associated with bone parameters when weight, height and sex were accounted for. The present results suggest that an increase in fat mass over 2 years is associated with an increase in BA and BMC, but a decrease in BMD in the whole body. An increase in LBM accrual, on the other hand, is positively associated with all bone parameters in the body. Fitness is associated with both BMC and BMD but not BA.

Distinct relationships of intramuscular and subcutaneous fat with cortical bone: findings from a cross-sectional study of young adult males and females

CONTEXT

Intracellular fat within muscle and visceral tissue has been suggested to adversely influence bone development.

OBJECTIVE

The aim of the study was to evaluate associations between im fat, as reflected by muscle density as measured by peripheral quantitative computed tomography, and cortical bone parameters in young adults.

DESIGN/SETTING/PARTICIPANTS

We conducted a cross-sectional analysis of 1703 males and 2243 females aged 17.8 years from the Avon Longitudinal Study of Parents and Children.

OUTCOME MEASURES

We measured cortical bone parameters from midtibial peripheral quantitative computed tomography scans.

RESULTS

Muscle density (inversely related to im fat) was inversely associated with periosteal circumference (PC) (beta = -0.07 [95% confidence interval (CI), -0.1, -0.04]), cortical bone mineral density (BMDC) (beta = -0.21 [95% CI, -0.26, -0.17]), and cortical thickness (CT) (beta = -0.37 [95% CI, -0.42, -0.33]) (males and females combined, adjusted for age, height, gender, and muscle cross-sectional area). In contrast, sc fat area was positively associated with PC (beta = 0.10 [95% CI, 0.07, 0.12]), but no association was seen with BMDC or CT. To examine the role of candidate intermediary metabolic pathways, analyses were repeated after adjustment for insulin, C-reactive protein, and β-C-telopeptides of type I collagen. Whereas similar associations were observed after adjustment for insulin and C-reactive protein, the association between muscle density and BMDC was partially attenuated by adjustment for β-C-telopeptides of type I collagen (beta = -0.14 [95% CI, -0.20, -0.08]).

CONCLUSION

Although im and sc fat were both positively associated with cortical bone mass, the nature of these relationships differed in that im fat was predominantly associated with CT and BMDC, whereas sc fat was mainly associated with PC. These relationships were largely independent of candidate metabolic pathways, such as altered bone resorption, insulin resistance, or inflammation.

Adequate vitamin D status and adiposity contribute to bone health in peripubertal nonobese children

The dietary reference intake (DRI) of vitamin D for Korean children was reduced from 400 IU/day in 2005 to 200 IU/day in 2010. We evaluated the risk factors for low 25-hydroxyvitamin D [25(OH)D] status and its relationships with bone health in peripubertal nonobese children living in Seoul or Gyeonggi-do. One hundred children (9.3 ± 1.9 years, 71 prepubertal, 45 boys) participated in the winter (n = 38, December through March) and summer (June through September). Bone mineral content (Z_BMC), fat mass (Z_FM), lean mass (Z_LM), and bone mineral density for the total body (Z_TB) and lumbar spine (Z_L1-4) were measured using dual-energy X-ray absorptiometry. Twenty-nine percent of children (47.4 % in winter, 17.7 % in summer) were vitamin D deficient (25(OH)D level of <20 ng/mL). The winter season (P = 0.008) and low vitamin D intake (P = 0.044) were associated with low 25(OH)D level. The 25(OH)D level correlated positively with Z_BMC (P = 0.040), Z_TB (P = 0.027), and Z_L1-4 (P = 0.045) independently of sex, puberty, Z_FM, Z_LM, physical activity level, and calcium intake. Z_FM correlated independently with Z_BMC (P < 0.001), Z_TB (P = 0.037), and Z_L1-4 (P < 0.001). In conclusion, almost half of peripubertal nonobese children were vitamin D deficient in winter. Adequate vitamin D status and adiposity contributed to good bone health in nonobese children. Considering the beneficial effects of adequate vitamin D status on bone health, the current DRI may be insufficient for preventing vitamin D deficiency in winter among Korean children.

Vitamin D deficiency in children with a chronic illness-seasonal and age-related variations in serum 25-hydroxy Vitamin D concentrations

Introduction

Children and adolescents with a chronic illness have potential risk factors for vitamin D deficiency. An optimal vitamin D status might have multiple health effects. This study evaluated vitamin D status and its association with age, gender, and season in a large cohort of chronically ill Finnish patients at a tertiary pediatric outpatient clinic. A cross-sectional register-based study was carried out, involving altogether 1351 children (51% boys, age range 0.2–18 years), who visited the outpatient clinic during 2007–2010 and had their vitamin D status (S-25-OHD) determined. A post-doc analysis was conducted to identify predisposing and preventing factors for vitamin D deficiency.

Results

Almost half (47%) of the S-25-OHD values were consistent with subnormal vitamin D status (S-25-OHD <50 nmol/L) while only 12% were >80 nmol/L. Age and season were the most important determinants for S-25-OHD concentration. Mean S-25-OHD concentration differed between age groups (Kruskal-Wallis; p<0.001), adolescents being at highest risk for vitamin D insufficiency. Young age and vitamin D supplementation were preventive factors for deficiency, while non-Finnish ethnic background was a predisposing factor. S-25-OHD showed significant seasonal variation in children older than 6 years. In the whole cohort, S-25-OHD was on average 13 nmol/L higher in summer than in winter, and the prevalence of vitamin D deficiency ( =  S-25-OHD <37.5 nmol/l) varied from 11% in summer to 29% in winter.

Conclusions

The finding that almost half of the studied Finnish children with a chronic illness had suboptimal vitamin D status is alarming. Inferior vitamin D status was noted in adolescents compared with younger children, suggesting that imbalance between intake and requirement evolves with age. Although less common during summer, subnormal vitamin D status was still observed in 28% of those evaluated in summer. Clinicians should identify individuals at risk and actively recommend vitamin D supplementation.

Long-term skeletal consequences of childhood acute lymphoblastic leukemia in adult males: a cohort study

OBJECTIVE

Long-term health sequelae of childhood-onset acute lymphoblastic leukemia (ALL) remain largely unknown. Low bone mineral content (BMC) and bone mineral density (BMD) are recognized complications, but it is unknown whether these persist until adulthood. We evaluated skeletal characteristics and their association with ALL therapy in long-term male ALL survivors.

DESIGN

This cross-sectional cohort study included 49 long-term male ALL survivors and 55 age-matched healthy males.

METHODS

BMD and compression fractures were assessed by dual-energy X-ray absorptiometry; blood biochemistry was obtained for parameters of calcium homeostasis.

RESULTS

The ALL survivors (median age 29 years, range 25-38 years), assessed 10-38 years after ALL diagnosis, had lower lumbar spine (P<0.001), femoral neck (P<0.001), and whole-body (P=0.017) BMD than expected based on normative values. When compared with the controls (median age 30 years, range 24-36 years), the ALL survivors had lower lumbar spine BMC (P=0.014), lower whole-body BMC (P<0.001), and lower whole-body BMD (P<0.001), but the differences were partly explained by differences in height. Altogether, 20% of the ALL survivors had spinal compression fractures, but these were equally prevalent in the controls. Males diagnosed with ALL before age 5 years had significantly lower BMD values. Other recognized risk factors included untreated hypogonadism, vitamin D deficiency, hypophosphatemia, low IGF-binding protein-3, and low physical activity.

CONCLUSIONS

At young adulthood, long-term male ALL survivors have significantly reduced BMC and BMD and a high prevalence of spinal compression fractures. Careful follow-up and active treatment of the recognized risk factors are warranted.

Correlation between body mass index and orthodontic treatment outcome

OBJECTIVE

To determine whether there is a correlation between body mass index (BMI), patient cooperation, and treatment success during multibracket (MB) appliance therapy.

MATERIALS AND METHODS

All adolescent MB patients started and finished between 2007 and 2010 were analyzed. The pretreatment BMI was calculated and negative file entries such as bad oral hygiene, missed appointments, and appliance breakage were recorded. According to the number of negative entries, cooperation was classified as good, bad, or poor. Additionally, the treatment duration and the number of appointments were recorded. For the evaluation of treatment success, the pretreatment and posttreatment PAR (peer assessment rating) scores were measured.

RESULTS

Of the 77 subjects, 61 had a normal BMI (79.2%) and 16 were considered overweight (20.8%). Whereas 51.7% of the normal-weight children had a good cooperation, only 25% of the overweight patients cooperated sufficiently. Consequently, the number of patients exhibiting bad or poor cooperation was higher in the overweight group (37.5% bad, 37.5% poor) than in the normal-weight group (30.6% bad, 17.7% poor). Patients with an increased BMI had a slightly longer treatment duration (21.4 months) and needed more appointments (19.9) than their normal-weight peers (18.9 months, 18.1 appointments). The PAR (peer assessment rating) score reduction, however, was comparable (normal BMI: 17.8 points, 64.0%; increased BMI: 15.2 points, 65.3%).

CONCLUSION

In the present study, children with increased BMI did not cooperate as well during MB therapy as their normal-weight peers, but the treatment outcome was comparable in the two groups.

Calcium homeostasis may influence resting energy expenditure with effects most apparent in early pubertal girls

AIM

Perturbations in dietary and hormonal components of the calciotropic network may be mediated through the influence of calcium homoeostasis on resting energy expenditure (REE). We investigated the association of dietary and hormonal factors involved in the regulation of calcium homoeostasis with REE in girls.

METHODS

Thirty-six girls aged 7-11 years participated. REE was assessed by indirect calorimetry, and body composition, dietary intake (calcium, vitamins D and K, phosphorus) and serum hormones (PTH, osteocalcin, 25OHD) were evaluated by DXA, 24 h recall and serum assay, respectively.

RESULTS

  A positive association between vitamin K and REE and an inverse association of parathyroid hormone (PTH) with REE (p = 0.05) were observed. PTH and REE were positively related in those having normal adiposity (p = 0.03) and inversely related in those with excess adiposity (p = 0.01). The association of REE with vitamin K intake was evident in lean individuals (p = 0.001), but was null in those with excess adiposity.

CONCLUSION

Decreased calciotropic hormone levels along with increased related nutrient intakes were associated with greater REE, although these relationships differed according to adiposity. The physiologic response to the diet and subsequent energy partitioning needs to be considered in the context of puberty. In particular, regulation and signalling of the calciotropic network during pubertal maturation warrant investigation.

Impaired bone health in inflammatory bowel disease: a case-control study in 80 pediatric patients

Previous studies have indicated that children with inflammatory bowel disease (IBD) may not achieve optimal bone mass. We evaluated the skeletal characteristics in children and adolescents with IBD. This cross-sectional cohort study comprised 80 IBD patients (median age 14.9 years, range 5-20) with a median disease duration of 3.4 years; 51 had ulcerative colitis, 26 Crohn disease, and 3 unspecified colitis. Eighty age- and gender-matched healthy subjects served as controls. Areal bone mineral density (aBMD), body composition, and vertebral fractures (VFs) were assessed by DXA. Bone age (BA) was determined for IBD patients. Findings were correlated with disease- and treatment-related parameters and biochemistry. IBD patients had lower BA-adjusted lumbar spine and whole-body aBMD (p < 0.001 for both) and whole-body BMC adjusted for height (p = 0.02) than controls. Lean mass and fat mass Z scores did not differ between the groups, but IBD patients had lower whole-body BMC relative to muscle mass (p = 0.006). Despite vitamin D supplementation in 48 %, vitamin D deficiency was common. In IBD cumulative weight-adjusted prednisolone dose >150 mg/kg for the preceding 3 years increased the risk for low whole-body aBMD (OR = 5.5, 95 % CI 1.3-23.3, p = 0.02). VFs were found in 11 % of patients and in 3 % of controls (p = 0.02). IBD in childhood was associated with low aBMD and reduced bone mass accrual relative to muscle mass; the risk for subclinical VFs may be increased. These observations warrant careful follow-up and active preventive measures.

Peripheral quantitative computed tomography (pQCT) reveals alterations in the three-dimensional bone structure in children with haemophilia

Children with haemophilia are at risk of suboptimal bone mass accrual and low bone mineral density (BMD). We recently demonstrated that although BMD in Finnish children with haemophilia was within the normal range, their whole body BMD was significantly lower and hypercalciuria more prevalent than in controls. This study sought to determine the bone structure and strength in physically active children with haemophilia. To investigate the underlying mechanisms in this group, we conducted a case-control study to assess bone structure and strength by peripheral quantitative computed tomography (pQCT) at the radius. The study group comprised 29 patients (mean age 12.2 years) and 46 age-matched controls. Children with haemophilia had decreased total BMD Z-score at the distal radius (P ≤ 0.001), but increased cortical bone density at the proximal radius (P ≤ 0.001). Total bone area at the proximal radius was significantly lower in children with haemophilia (P = 0.002), whereas there were no differences in cortical bone area or in polar Strength-Strain Index, a parameter of bone strength, between the patients and controls. Patients with mild to moderate haemophilia and on-demand treatment had inferior bone strength compared to those with moderate to severe haemophilia and prophylaxis. Our findings suggest altered skeletal development in patients with haemophilia in the radius, resulting in smaller bone size and higher cortical bone density. Importantly, bone strength at the radius appears equal to healthy children. Prophylactic treatment seems to have a beneficial effect on bone health.

Impaired bone health and asymptomatic vertebral compressions in fracture-prone children: a case-control study

Frequent fractures in children may be a sign of impaired bone health, but it remains unestablished when and how fracture-prone children should be assessed. This prospective study elucidated skeletal characteristics and predisposing factors in children with recurrent fractures. Findings were used to establish guidelines for screening. During a 12-month period we recorded fracture history for all children (n = 1412) treated for an acute fracture at a large university hospital. All apparently healthy children over 4 years of age, who had sustained: (1) at least one vertebral fracture; (2) two long-bone fractures before age 10 years; or (3) three long-bone fractures before age 16 years, were recruited. They underwent dual-energy X-ray absorptiometry (DXA), laboratory tests, and spinal radiography. Information regarding family history and lifestyle factors were collected. Findings were compared with healthy controls. Sixty-six fracture-prone children (44 males, mean age 10.7 years; 5% of all children with fractures) were identified. Altogether, they had sustained 183 long-bone fractures (median 3, range 0–7); 11 children had sustained vertebral fracture(s). Patients had significantly lower bone mineral density (BMD) at lumbar spine (p < 0.001), hip (p = 0.007), and whole body (p < 0.001) than the controls; only 5 children (8%) had a BMD Z-score < −2.0. Asymptomatic vertebral compressions were prevalent, especially in those under 10 years of age. Hypercalciuria (11%) and hyperphosphaturia (22%) were significantly more prevalent than in controls. Serum concentration of 25-hydroxyvitamin D (S-25OHD) was below 50 nmol/L in 55%; low levels were associated with low BMD and vertebral compressions. The fracture-prone children had lower calcium intake, less physical activity, and more often had siblings with fractures than the controls. The findings suggest that a thorough pediatric evaluation, including DXA and spinal radiography, is often indicated already after a second significant low-energy fracture in children, in order to detect potentially preventable adverse lifestyle factors and nutritional deficits and to identify those with compromised overall bone health.

Long term higher urinary calcium excretion within the normal physiologic range predicts impaired bone status of the proximal radius in healthy children with higher potential renal acid load

Reduced bone mineral density (BMD) and bone mass have been observed in children with idiopathic hypercalciuria. Whether urinary calcium excretion at the higher end of the normal physiologic range can influence bone health in healthy children independent of dietary intake is unknown. Urinary calcium was quantified in 603 24-h urine samples from 154 healthy children and adolescents who had ≥3 urine collections and parallel 3-day weighed dietary records during the 4years preceding proximal forearm bone analyses by peripheral quantitative computed tomography (pQCT). Urinary potential renal acid load (uPRAL) was determined according to urine ionogram by subtracting measured quantitatively important mineral cations from nonbicarbonate anions. Urinary calcium excretion was significantly associated with volumetric (v)BMD (P=0.04), almost significantly with cortical bone mineral content (BMC) (P=0.05), but not with cortical cross-sectional area (CSA) (P=0.09), total CSA (P=0.3), or Strength-Strain Index (P=0.8) in the total population sample. Stratified analyses based on the median split of uPRAL showed that calcium excretion was negatively associated with vBMD (P=0.007), cortical BMC (P=0.001), and cortical CSA (P=0.004) in those children with higher uPRALs, but not in those with low uPRALs (P>0.3). In conclusion, long-term higher calciuria within the physiological range predicts reduced diaphyseal bone mass and bone density particularly in healthy children and adolescents with long-term unfavorable higher dietary acid load, i.e., with lower fruit and vegetable intake.

Overweight in childhood and bone density and size in adulthood

We evaluated the adult bone structural traits in relation to childhood overweight in 832 men and women. Childhood overweight was associated with larger cross-sections at long bones in both sexes. Excess weight in childhood may also lead to higher trabecular density in females and somewhat lower cortical density in men.

INTRODUCTION

Excess body weight in childhood may impose more loading on growing skeleton and thus lead to more robust structure in adulthood.

METHODS

This prospective cohort study evaluated the adult bone structural traits in relation to childhood overweight in a subgroup of 456 women and 376 men from the population-based cohort of Cardiovascular Risks in Young Finns Study. Between-group differences were evaluated with analysis of covariance.

RESULTS

According to established body mass index (BMI) criterion at the age of 12 years, 31 women and 34 men were classified overweight in childhood. At the mean age (SD) of 36.1 (2.7) years, total cross-sectional (ToA) and cortical area (CoA) at the distal and shaft sites and cortical (shaft CoD) and trabecular (distal TrD) bone density of the nonweight-bearing radius and weight-bearing tibia were evaluated with pQCT. Despite being taller in adolescence, the adult body height of overweight children was similar. In both sexes, childhood overweight was consistently associated with 5-10% larger ToA at all bone sites measured in adulthood. CoA did not show such a consistent pattern. Women, who were overweight in childhood, had ~5% denser TrD with no difference in CoD. In contrast, TrD in men who were overweight in childhood was not different but their CoD was ~1% lower.

CONCLUSIONS

Childhood overweight was consistently associated with larger long bone cross-sections in both sexes. Excess weight in childhood may also lead to higher trabecular density in women and somewhat lower cortical density in men. Specific mechanisms underlying these associations are not known.

Quantitative computed tomography and computed tomography in children

Quantitative computed tomography (QCT) methodologies have been instrumental in deepening our understanding of bone acquisition and strength during childhood. Important publications in the last year have drawn attention to the functional muscle-bone unit, showing that factors such as population ancestry, bone size, and muscle composition are additional dimensions of bone strength that affect muscle-bone relationships. The role of adiposity in pediatric bone health is complex and may vary by sex, puberty stage, and degree of obesity. Several new studies have demonstrated the association of peripheral QCT (pQCT) outcomes with fracture, although pQCT outcomes are not superior to dual-energy x-ray absorptiometry measures in this regard. New high-resolution pQCT studies document transient weakness in mid-puberty that coincides developmentally with the period of peak fracture incidence. These new studies will ultimately help us understand the development of sex differences in bone strength that emerge in adolescence.

Prevalence of vertebral compression fractures and associated factors in children and adolescents with severe juvenile idiopathic arthritis

OBJECTIVE

Vertebral fractures occur in patients with juvenile idiopathic arthritis (JIA), but data on their frequency and causes are scarce. Our cross-sectional study evaluated prevalence of compression fractures and associated factors in a high-risk pediatric population with severe JIA.

METHODS

Children and adolescents with a history of treatment-resistant polyarticular-course JIA for ≥ 5 years or systemic arthritis for ≥ 3 years were recruited. Clinical examination, dietary recall, laboratory measurements, bone mineral density (BMD) measurement by dual-energy X-ray absorptiometry, and spinal radiography were performed.

RESULTS

Our study included 50 patients (41 girls), of whom 6 (12%) had systemic arthritis, with a median age of 14.8 years (range 7.0-18.7 yrs) and median disease duration of 10.2 years (range 3.9-16.8 years). Ninety-four percent had used systemic glucocorticoids (GC); the median total duration of GC treatment was 7.1 years (range 0-15.5 yrs). The median weight-adjusted cumulative GC dose for the preceding 3 years was 72 mg/kg (range 0-911 mg/kg). The median bone age-corrected lumbar spine and whole-body areal BMD Z-scores were -0.8 and -1.0, respectively. Twenty-two percent had vertebral fractures, mostly thoracic. Compression fractures were associated with high disease activity, high body mass index (BMI), and high recent cumulative GC dose, but not with disease duration or BMD. Thirty percent had sustained at least 1 peripheral low energy fracture. Twenty-six percent were deemed to have significantly compromised bone health.

CONCLUSION

Severe JIA is associated with a significant risk of vertebral compression fractures. Associated factors include high disease activity, high BMI, and high recent GC exposure. Further studies are needed to establish optimal prevention and treatment guidelines.

Bone biopsy findings and correlation with clinical, radiological, and biochemical parameters in children with fractures

In children the diagnosis of osteoporosis is based on fracture history and DXA-derived BMD. Bone biopsy is an invasive but accurate method for studying bone characteristics. In this study we evaluated bone biopsy findings and their correlation with noninvasive measures of bone health. Transiliac bone biopsy was performed on 24 consecutive children (17 boys, median age 12 years, range 6 to 16 years) evaluated for suspected primary osteoporosis. Biopsy findings were compared with normative data and correlated with clinical, radiological, biochemical, and densitometric findings. The patients had sustained altogether 64 nonvertebral fractures (median 2.5) from low- or moderate-energy traumas, and 14 patients (58%) had vertebral fractures. The median lumbar spine BMD Z-score was -1.2 (range -3.1 to +1.0). Hypovitaminosis D was present in 58%. Histomorphometry showed low bone volume in 7 patients and normal bone volume in 17. Bone turnover was high in 7, low in 7, and normal in 10 patients. Histomorphometric findings correlated poorly with fracture history, serum bone turnover markers, and DXA findings. Vitamin D deficiency and low lumbar BMD were associated with high bone turnover in the biopsy. These findings underscore the difficulties in diagnosing pediatric osteoporosis. Bone histomorphometry gives additional information and may be useful when considering bisphosphonate treatment in children with suspected primary osteoporosis.