Long-term inflammation and glucocorticoid therapy impair skeletal modeling during growth in childhood Crohn disease

Micronutrient status during pregnancy is associated with child immune status in rural Bangladesh

Background

Poor immune function increases children's risk of infection and mortality. Several maternal factors during pregnancy may affect infant immune function during the postnatal period.

Objectives

We aimed to evaluate whether maternal micronutrients, stress, estriol, and immune status during the first or second trimester of pregnancy were associated with child immune status in the first two years after birth.

Methods

We conducted observational analyses within the water, sanitation, and hygiene (WASH) Benefits Bangladesh randomized controlled trial. We measured biomarkers in 575 pregnant women and postnatally in their children. Maternal biomarkers measured during the first and second trimester of pregnancy included nutrition status via vitamin D (25-hydroxy-D [25(OH)D]), ferritin, soluble transferrin receptor (sTfR), and retinol-binding protein (RBP); cortisol; estriol. Immune markers were assessed in pregnant women at enrollment and their children at ages 14 and 28 mo, including C-reactive protein (CRP), alpha-1-acid glycoprotein (AGP), and 13 cytokines (including IFN-γ). We generated a standardized sum score of log-transformed cytokines. We analyzed IFN-γ individually because it is a critical immunoregulatory cytokine. All outcomes were prespecified. We used generalized additive models and reported the mean difference and 95% confidence intervals at the 25th and 75th percentiles of exposure distribution.

Results

At child age 14 mo, concentrations of maternal RBP were inversely associated with the cytokine sum score in children (-0.34 adjusted difference between the 25th and 75th percentile [95% confidence interval -0.61, -0.07]), and maternal vitamin A deficiency was positively associated with the cytokine sum score in children (1.02 [0.13, 1.91]). At child age of 28 mo, maternal RBP was positively associated with IFN-γ in children (0.07 [0.01, 0.14]), whereas maternal vitamin A deficiency was negatively associated with child AGP (-0.07 [-0.13, -0.02]). Maternal iron deficiency was associated with higher AGP concentrations in children at age 14 mo (0.13 [0.04, 0.23]), and maternal sTfR concentrations were positively associated with child CRP concentrations at age 28 mo (0.18 [0, 0.36]).

Conclusion

Maternal deficiencies in vitamin A or iron during the first 2 trimesters of pregnancy may shape the trajectory of a child's immune status.

Predicting Outcomes in Pediatric Crohn's Disease for Management Optimization: Systematic Review and Consensus Statements From the Pediatric Inflammatory Bowel Disease-Ahead Program

BACKGROUND & AIMS

A better understanding of prognostic factors within the heterogeneous spectrum of pediatric Crohn's disease (CD) should improve patient management and reduce complications. We aimed to identify evidence-based predictors of outcomes with the goal of optimizing individual patient management.

METHODS

A survey of 202 experts in pediatric CD identified and prioritized adverse outcomes to be avoided. A systematic review of the literature with meta-analysis, when possible, was performed to identify clinical studies that investigated predictors of these outcomes. Multiple national and international face-to-face meetings were held to draft consensus statements based on the published evidence.

RESULTS

Consensus was reached on 27 statements regarding prognostic factors for surgery, complications, chronically active pediatric CD, and hospitalization. Prognostic factors for surgery included CD diagnosis during adolescence, growth impairment, NOD2/CARD15 polymorphisms, disease behavior, and positive anti-Saccharomyces cerevisiae antibody status. Isolated colonic disease was associated with fewer surgeries. Older age at presentation, small bowel disease, serology (anti-Saccharomyces cerevisiae antibody, antiflagellin, and OmpC), NOD2/CARD15 polymorphisms, perianal disease, and ethnicity were risk factors for penetrating (B3) and/or stenotic disease (B2). Male sex, young age at onset, small bowel disease, more active disease, and diagnostic delay may be associated with growth impairment. Malnutrition and higher disease activity were associated with reduced bone density.

CONCLUSIONS

These evidence-based consensus statements offer insight into predictors of poor outcomes in pediatric CD and are valuable when developing treatment algorithms and planning future studies. Targeted longitudinal studies are needed to further characterize prognostic factors in pediatric CD and to evaluate the impact of treatment algorithms tailored to individual patient risk.

Peripheral quantitative computed tomography (pQCT) in 12- and 24-month-old children - Practical aspects and descriptive data

BACKGROUND

Peripheral quantitative computed tomography (pQCT) is a useful tool to assess detailed bone characteristics. Its utility in infants is however limited due to lack of reference data and technical challenges. The purpose of this study was to provide data on length- and weight-adjusted pQCT values and to present a quality grading system for healthy children aged 12 and 24 months.

MATERIAL AND METHODS

As a part of the Vitamin D intervention in Infants (VIDI) trial, we collected pQCT and anthropometric data from 855 children at 12 months and from 784 children at 24 months. Bone mineral content (BMC; mg/mm), volumetric bone mineral density (vBMD; mg/cm³), cross-sectional area (CSA; mm²), polar-moment of inertia (PMI; mm⁴), and periosteal circumference (PsC; mm) were assessed for total bone at 20% distal site of the left tibia using pQCT (Stratec XCT2000L). We evaluated the impact of scan quality on bone measures. Total bone parameters were assessed for boys and girls separately. The means of the bone parameters were also compared in relation to age. The associations between bone parameters and weight, length, sex and scan quality were analyzed.

RESULTS

We included scans with sufficient quality (Grade 1-5) in the final analyses: 679/855 (79%) at 12 months and 709/784 (90%) at 24 months. Altogether 39% of the scans at 12 months and 51% at 24 months were of good or excellent quality (Grade 1-2). Scan quality had an impact on BMCs at 12 and 24 months (p = 0.001 and p = 0.017, respectively) but not on other bone parameters. Boys presented greater total bone BMC, CSA, PMI and PsC values at 12 and 24 months but vBMDs were similar. All bone parameters showed a significant increase between 12 and 24 months for both sexes. When adjusting bone parameters for weight, length and scan quality, differences between sexes disappeared. Weight was the strongest modifier of BMC, CSA, PMI and PsS at 12 and 24 months.

CONCLUSIONS

This study increases our understanding on bone parameters in young children and demonstrates the suitability of pQCT in bone research in infants. The described pQCT data and scan quality grading system should prove useful in evaluating data reliability in research settings.

CLINICAL TRIAL REGISTRATION NUMBER

NCT1723852.

Muscle deficits with normal bone microarchitecture and geometry in young adults with well-controlled childhood-onset Crohn's disease

BACKGROUND

Muscle-bone deficits are common in pediatric Crohn's disease; however, few studies have assessed long-term musculoskeletal outcomes in adults with childhood-onset Crohn's disease. This study assessed the prevalence of musculoskeletal deficits in young adults with childhood-onset Crohn's disease compared with healthy controls.

METHODS

High-resolution MRI and MR spectroscopy were used to assess bone microarchitecture, cortical geometry and muscle area, and adiposity at distal femur and bone marrow adiposity (BMA) at lumbar spine. Muscle function and biomarkers of the muscle-bone unit were also assessed.

RESULTS

Twenty-seven adults with Crohn's disease with median (range) age 23.2 years (18.0, 36.1) and 27 age and sex-matched controls were recruited. Trabecular microarchitecture, cortical geometry and BMA were not different between Crohn's disease and controls (P > 0.05 for all). Muscle area was lower (P = 0.01) and muscle fat fraction was higher (P = 0.04) at the distal femur in Crohn's disease compared to controls. Crohn's disease participants had lower grip strength [-4.3 kg (95% confidence interval (CI), -6.8 to -1.8), P = 0.001] and relative muscle power [-5.0 W/kg (95% CI, -8.8 to -1.2), P = 0.01]. Crohn's disease activity scores negatively associated with trabecular bone volume (r = -0.40, P = 0.04) and muscle area (r = -0.41, P = 0.03).

CONCLUSION

Young adults with well-controlled Crohn's disease managed with contemporary therapies did not display abnormal bone microarchitecture or geometry at the distal femur but exhibited muscle deficits. The observed muscle deficits may predispose to musculoskeletal morbidity in future and interventions to improve muscle mass and function warrant investigation.

Ulcerative Colitis-Diagnostic and Therapeutic Algorithms

BACKGROUND

Ulcerative colitis is a chronic inflammatory bowel disease with an estimated 150 000 patients in Germany alone.

METHODS

This review is based on publications about current diagnostic and therapeutic strategies for ulcerative colitis that were retrieved by a selective search in PubMed, and on current guidelines.

RESULTS

The primary goal of treatment is endoscopically confirmed healing of the mucosa. Mesalamine, in various forms of administration, remains the standard treatment for uncomplicated ulcerative colitis. Its superiority over placebo has been confirmed in meta-analyses of randomized, controlled trials. Glucocorticoids are highly effective in the acute treatment of ulcerative colitis, but they should only be used over the short term, because of their marked side effects. Further drugs are available to treat patients with a more complicated disease course of ulcerative colitis, including azathioprine, biological agents, JAK inhibitors (among them TNF antibodies, biosimilars, ustekinumab, vedolizumab, and tofacitinib), and calcineurin inhibitors. Proctocolectomy should be considered in refractory cases, or in the presence of high-grade epithelial dysplasia. Ulcerative colitis beginning in childhood or adolescence is often characterized by rapid progression and frequent comorbidities that make its treatment a special challenge.

CONCLUSION

A wide variety of drugs are now available for the treatment of ulcerative colitis, enabling the individualized choice of the best treatment for each patient. Regular surveillance colonoscopies to rule out colon carcinoma should be scheduled at intervals that depend on risk stratification.

Medium-term outcomes of total hip arthroplasty in juvenile patients

BACKGROUND

Juvenile hip osteoarthritis is often the end result of congenital conditions or acquired hip ailments occurred during the paediatric age. This study evaluated the middle term results of total hip arthroplasty for end-stage juvenile hip osteoarthritis.

MATERIALS AND METHODS

This is a retrospective analysis of prospectively collected data on a cohort of 10 consecutive patients (12 hips), aged between 14 and 20 at operation, who underwent cementless total hip arthroplasty for end-stage juvenile secondary hip osteoarthritis in two orthopaedic tertiary referral centres between 2009 and 2018.

RESULTS

Juvenile hip osteoarthritis occurred as a consequence of developmental dysplasia of the hip, Legg-Calvé-Perthes disease, femoral head necrosis or slipped capital femoral epiphysis. All patients showed a significant improvement in Harris Hip Score (p < 0.01) at 3.3 years average follow-up (range 0.7-10.1 years).

CONCLUSION

The management of juvenile hip osteoarthritis following developmental dysplasia of the hip, Legg-Calvé-Perthes disease, femoral head necrosis or slipped capital femoral epiphysis is still challenging. Careful preoperative planning is essential to achieve good outcomes and improve the Harris Hip Score in these young patients. Total hip arthroplasty is a suitable option for end-stage secondary juvenile hip osteoarthritis, when proximal femoral osteotomies and conservative treatments fail to improve patients' symptoms and quality of life.

LEVEL OF EVIDENCE

IV.

Partial enteral nutrition has no benefit on bone health but improves growth in paediatric patients with quiescent or mild Crohn's disease

BACKGROUND AND AIMS

Exclusive enteral nutrition induces remission, improves bone health and growth in paediatric Crohn's disease (CD) patients, but is highly demanding for patients. We investigated efficacy of partial enteral nutrition (PEN) on bone health, growth and course in CD patients and assessed microbial and metabolic changes induced by PEN.

METHODS

We performed a two centre, non-randomized controlled intervention study in quiescent CD patients aged <19 years. Patients in intervention group received a liquid formula providing ~25% of daily energy for one year. At baseline, after 3, 6, 9 and 12 months, we collected data on bone, muscle (peripheral quantitative computertomography), anthropometry, disease activity (weighted paediatric CD activity index), metabolomic profile (liquid chromatography mass spectrometry), and faecal microbiome (16S rRNA gene sequencing).

RESULTS

Of 41 CD patients, 22 received the intervention (PEN) (mean age 15.0 ± 1.9 years, 50% male), 19 served as controls (non-PEN) (12.8 ± 3.1 years, 58% male). At baseline, mean bone quality was comparable to reference population with no improvement during the intervention. Relapse rate was low (8/41, PEN 4/22 and non-PEN 4/19, ns). PEN was not associated with microbiota community changes (beta diversity) but significantly reduced species diversity. Metabolome changes with upregulation of phosphatidylcholines in PEN patients are likely related to lipid and fatty acid composition of the formula. PEN significantly improved growth in a subgroup with Tanner stage 1-3.

CONCLUSION

In our cohort of paediatric CD patients, PEN did not affect bone health but improved growth in patients with a potential to grow.

Pediatric Bone Mineral Accrual Z-Score Calculation Equations and Their Application in Childhood Disease

Annual gains in BMC and areal bone mineral density (aBMD) in children vary with age, pubertal status, height-velocity, and lean body mass accrual (LBM velocity). Evaluating bone accrual in children with bone health-threatening conditions requires consideration of these determinants. The objective of this study was to develop prediction equations for calculating BMC/aBMD velocity SD scores (velocity-Z) and to evaluate bone accrual in youth with health conditions. Bone and body compositions via DXA were obtained for up to six annual intervals in healthy youth (n = 2014) enrolled in the Bone Mineral Density in Childhood Study (BMDCS) . Longitudinal statistical methods were used to develop sex- and pubertal-status-specific reference equations for calculating velocity-Z for total body less head-BMC and lumbar spine (LS), total hip (TotHip), femoral neck, and 1/3-radius aBMD. Equations accounted for (1) height velocity, (2) height velocity and weight velocity, or (3) height velocity and LBM velocity. These equations were then applied to observational, single-center, 12-month longitudinal data from youth with cystic fibrosis (CF; n = 65), acute lymphoblastic leukemia (ALL) survivors (n = 45), or Crohn disease (CD) initiating infliximab (n = 72). Associations between BMC/aBMD-Z change (conventional pediatric bone health monitoring method) and BMC/aBMD velocity-Z were assessed. The BMC/aBMD velocity-Z for CF, ALL, and CD was compared with BMDCS. Annual changes in the BMC/aBMD-Z and the BMC/aBMD velocity-Z were strongly correlated, but not equivalent; LS aBMD-Z = 1 equated with LS aBMD velocity-Z = -3. In CF, BMC/aBMD velocity-Z was normal. In posttherapy ALL, BMC/aBMD velocity-Z was increased, particularly at TotHip (1.01 [-.047; 1.7], p < 0.0001). In CD, BMC/aBMD velocity-Z was increased at all skeletal sites. LBM-velocity adjustment attenuated these increases (eg, TotHip aBMD velocity-Z: 1.13 [0.004; 2.34] versus 1.52 [0.3; 2.85], p < 0.0001). Methods for quantifying the BMC/aBMD velocity that account for maturation and body composition changes provide a framework for evaluating childhood bone accretion and may provide insight into mechanisms contributing to altered accrual in chronic childhood conditions. © 2018 American Society for Bone and Mineral Research.

Glucocorticoid treatment in juvenile idiopathic arthritis

Juvenile idiopathic arthritis (JIA) is the most common chronic rheumatic disease of joints in childhood. Glucocorticoids are being used in JIA treatment effectively for decades. Although systemic glucocorticoid use decreased with the introduction of biologic drugs, intraarticular glucocorticoid injections (IAGI) with nonsteroidal anti-inflammatory drugs and non-biologic disease modifying anti-rheumatic drugs (DMARDs) still remain the primary treatment in JIA, especially in oligoarticular subcategory. Systemic glucocorticoids are used mainly for severe JIA-associated complications such as macrophage activation syndrome (MAS), myocarditis, pericarditis, pleuritis, peritonitis, and severe anemia; as bridging therapy while waiting for the full therapeutic effect of DMARDs; and in certain occasions for patients with severe refractory uveitis. Since glucocorticoid administration is associated with many adverse events, it is important to use glucocorticoids in an optimum way balancing the risks and benefits. The aim of this review is to summarize the current knowledge on glucocorticoid treatment in JIA. A comprehensive literature search was conducted utilizing the Cochrane Library and MEDLINE/PubMed databases. The main topics include mechanism of action, dose, duration, adverse events, vaccination during glucocorticoid treatment, the place of glucocorticoids in JIA treatment guidelines and consensus treatment plans, glucocorticoid use in JIA-associated uveitis, MAS, and IAGI. Data from the literature provide guidance on how to use glucocorticoids in JIA treatment especially for IAGI and systemic use in systemic JIA and MAS. However, there is lack of evidence and need for prospective randomized studies in most parts including the indications in different JIA subcategories, optimum dose/route of administration/duration of treatment, and tapering strategies.

The Association of Diet and Exercise With Body Composition in Pediatric Crohn's Disease

BACKGROUND

In pediatric Crohn's disease, fat mass improves over time with treatment, but lean mass deficits persist. This observational study of the associations of physical activity and dietary intake with lean mass and muscle strength in children with Crohn's disease was ancillary to a previously reported randomized clinical trial of an intervention to improve bone health.

METHODS

In this study, 138 participants were followed at baseline and at 6, 12, and 24 months with evaluation of lean and fat mass using DXA, muscle strength (peak torque), Crohn's characteristics, dietary intake, time in moderate to vigorous physical activity (MVPA), and serum insulin-like growth factor-1 (IGF-1) and tumor necrosis factor-alpha (TNF-α). Race- and sex-specific Z-scores for leg lean mass and whole body fat mass were generated. Quasi least square regression evaluated determinants of changes in body composition and muscle strength.

RESULTS

Leg lean mass and muscle strength were positively associated with time in MVPA (P < 0.05) and negatively associated with increasing clinical disease activity (P < 0.05). Both leg lean mass and strength were positively associated with IGF-1 Z-score (P ≤ 0.03) but negatively associated with serum TNF-α (P ≤ 0.04). Neither lean mass nor muscle strength was associated with caloric or protein intake.

CONCLUSIONS

Persistence of lean mass deficits was related to ongoing Crohn's disease activity but improved with greater time spent in moderate to vigorous physical activity. Future trials are needed to evaluate the efficacy of physical activity in improving lean mass in pediatric Crohn's disease.

Inflammatory Bowel Disease: Effects on Bone and Mechanisms

Inflammatory bowel disease (IBD) is associated with decreased bone mass and alterations in bone geometry from the time of diagnosis, before anti-inflammatory therapy is instituted. Deficits in bone mass can persist despite absence of symptoms of active IBD. The effects of IBD on the skeleton are complex. Protein-calorie malnutrition, inactivity, hypogonadism, deficits in calcium intake and vitamin D consumption and synthesis, stunted growth in children, decreased skeletal muscle mass, and inflammation all likely play a role. Preliminary studies suggest that the dysbiotic intestinal microbial flora present in IBD may also affect bone at a distance. Several mechanisms are possible. T cells activated by the gut microbiota may serve as "inflammatory shuttles" between the intestine and bone. Microbe-associated molecular patterns leaked into the circulation in IBD may activate immune responses in the bone marrow by immune cells and by osteocytes, osteoblasts, and osteoclasts that lead to decreased bone formation and increased resorption. Finally, intestinal microbial metabolites such as H₂S may also affect bone cell function. Uncovering these mechanisms will enable the design of microbial cocktails to help restore bone mass in patients with IBD.

Increases in IGF-1 After Anti-TNF-α Therapy Are Associated With Bone and Muscle Accrual in Pediatric Crohn Disease

CONTEXT

Low levels of insulinlike growth factor 1 (IGF-1) in pediatric and adolescent Crohn disease (CD) likely contribute to bone and muscle deficits.

OBJECTIVE

Assess changes in IGF-1 levels and associations with bone and muscle accrual following initiation of anti-tumor necrosis factor α (TNF-α) therapy in pediatric and adolescent CD.

DESIGN AND PARTICIPANTS

Participants (n = 75, age 5 to 21 years) with CD were enrolled in a prospective cohort study; 63 completed the 12-month visit.

MAIN OUTCOME MEASURES

IGF-1 levels at baseline and 10 weeks, as well as dual-energy x-ray absorptiometry (DXA) and tibia peripheral quantitative computed tomography (pQCT) measures of bone and muscle at baseline and 12 months after initiation of anti-TNF-α therapy. Outcomes were expressed as sex-specific z scores.

RESULTS

IGF-1 z scores increased from a median (interquartile range) of -1.0 (-1.58 to -0.17) to -0.36 (-1.04 to 0.36) over 10 weeks (P < 0.001). Lesser disease severity and systemic inflammation, as well as greater estradiol z scores (in girls), was significantly associated with greater IGF-1 z scores over time. DXA whole-body bone mineral content, leg lean mass, and total hip and femoral neck bone mineral density (BMD) z scores were low at baseline (P < 0.0001 vs reference data) and increased significantly (P < 0.001) over 12 months. Greater increases in IGF-1 z scores over 10 weeks predicted improvement in DXA bone and muscle outcomes and pQCT trabecular BMD and cortical area. Adjustment for changes in muscle mass markedly attenuated the associations between IGF-1 levels and bone outcomes.

CONCLUSIONS

Short-term improvements in IGF-1 z scores predicted recovery of bone and muscle outcomes following initiation of anti-TNF-α therapy in pediatric CD. These data suggest that disease effects on growth hormone metabolism contribute to musculoskeletal deficits in CD.

Suppressor of cytokine signaling 2 (Socs2) deletion protects bone health of mice with DSS-induced inflammatory bowel disease

Individuals with inflammatory bowel disease (IBD) often present with poor bone health. The development of targeted therapies for this bone loss requires a fuller understanding of the underlying cellular mechanisms. Although bone loss in IBD is multifactorial, the altered sensitivity and secretion of growth hormone (GH) and insulin-like growth factor-1 (IGF-1) in IBD is understood to be a critical contributing mechanism. The expression of suppressor of cytokine signaling 2 (SOCS2), a well-established negative regulator of GH signaling, is stimulated by proinflammatory cytokines. Therefore, it is likely that SOCS2 expression represents a critical mediator through which proinflammatory cytokines inhibit GH/IGF-1 signaling and decrease bone quality in IBD. Using the dextran sodium sulfate (DSS) model of colitis, we reveal that endogenously elevated GH function in the Socs2^−/− mouse protects the skeleton from osteopenia. Micro-computed tomography assessment of DSS-treated wild-type (WT) mice revealed a worsened trabecular architecture compared to control mice. Specifically, DSS-treated WT mice had significantly decreased bone volume, trabecular thickness and trabecular number, and a resulting increase in trabecular separation. In comparison, the trabecular bone of Socs2-deficient mice was partially protected from the adverse effects of DSS. The reduction in a number of parameters, including bone volume, was less, and no changes were observed in trabecular thickness or separation. This protected phenotype was unlikely to be a consequence of improved mucosal health in the DSS-treated Socs2^−/− mice but rather a result of unregulated GH signaling directly on bone. These studies indicate that the absence of SOCS2 is protective against bone loss typical of IBD. This study also provides an improved understanding of the relative effects of GH/IGF-1 signaling on bone health in experimental colitis, information that is essential before these drugs are explored as bone protective agents in children and adults with IBD.

Summary: Using a mouse model of inflammatory bowel disease, this article provides an improved understanding of the relative effects of GH/IGF-1 on bone health in experimental colitis.

Structural Basis of Bone Fragility in Young Subjects with Inflammatory Bowel Disease: A High-resolution pQCT Study of the SWISS IBD Cohort (SIBDC)

BACKGROUND

The onset of inflammatory bowel disease (IBD) during childhood/adolescence compromises peak bone mass acquisition and predisposes to fractures later in life. However, the structural basis for bone fragility in young adults with IBD remains unknown.

METHODS

One hundred two young subjects from the Swiss IBD cohort were included. Areal bone mineral density (aBMD) at distal radius, hip, and spine as well as morphometric vertebral fractures were assessed using dual-energy x-ray absorptiometry technique. Volumetric (v)BMD, trabecular, and cortical bone microstructure at the distal radius and tibia were assessed by high-resolution peripheral quantitative computed tomography. Areal, vBMD, and microstructure were compared between patients with IBD and healthy matched controls (n = 389). Multiple regression analysis was used to evaluate variables associated with bone microarchitecture and fractures.

RESULTS

Clinical fractures were reported in 37 IBD subjects (mean age 23 yrs), mostly of the forearm; 5 subjects had morphometric vertebral fractures. After adjusting for age, sex, and height, tibia trabecular (Tb)vBMD, thickness, and distribution were significantly associated with fractures, whereas aBMD was not. After adjusting for aBMD, radius Tb distribution and tibia (Tb)vBMD and trabecular thickness still remained associated with fractures. Compared with healthy controls, patients with IBD had significantly lower aBMD at all sites, as well as alteration in (Tb)vBMD and trabecular microstructure at the distal radius and tibia, and these alterations were correlated with disease severity.

CONCLUSIONS

Young patients with IBD have low aBMD and altered trabecular bone microarchitecture compared with healthy controls. The latter is independently associated with fractures and may predispose increased susceptibility to fragility fractures throughout life.

Oral glucocorticoid use and osteonecrosis in children and adults with chronic inflammatory diseases: a population-based cohort study

OBJECTIVES

We studied oral glucocorticoids and osteonecrosis, a rare but serious bone disease, in individuals with various chronic inflammatory diseases. We hypothesised that we would find stronger associations in adults versus children and in people with autoimmune diseases.

DESIGN

Retrospective cohort study.

SETTING

Population-representative data (1994-2013) from general practices in the UK.

PARTICIPANTS

Children and adults diagnosed with asthma; inflammatory bowel disease; juvenile, psoriatic or rheumatoid arthritis; psoriasis; or systemic lupus.

EXPOSURES

Oral glucocorticoid patterns.

PRIMARY AND SECONDARY OUTCOME MEASURES

Diagnosed osteonecrosis (primary) and osteonecrosis plus clinical features (eg, symptoms, pain medication, surgical repair) (secondary). Discrete time failure models estimated the adjusted hazard ratio (aHR) of incident osteonecrosis following oral glucocorticoid exposure. Hypothesis testing was one sided (with corresponding 90% CI) since glucocorticoids were unlikely protective.

RESULTS

After adjusting for demographic, disease-related and health utilisation factors, glucocorticoid exposure was associated with osteonecrosis in adults (ages 18-49, aHR 2.1 (90% CI 1.5 to 2.9); ages ≥50, aHR 1.3 (90% CI 1.01 to 1.7)). However, low-dose glucocorticoids, corresponding to average doses <7.5 mg prednisolone daily and maximum doses <30 mg daily, were not associated with osteonecrosis in adults. Furthermore, even at high glucocorticoid doses, there was no evidence of increased osteonecrosis among glucocorticoid-exposed children (p=0.04 for interaction by age) (any glucocorticoid exposure, ages 2-9: aHR 1.1 (90% CI 0.7 to 1.7); ages 10-17: aHR 0.6 (90% CI 0.3 to 1.6)). Arthritis, inflammatory bowel disease and lupus were independently associated with osteonecrosis, but there was a similar dose relationship between glucocorticoids and osteonecrosis among adults with low-risk and high-risk diseases.

CONCLUSIONS

Glucocorticoid use was clearly associated with osteonecrosis in a dose-related fashion in adults, especially young adults, but this risk was not detectable in children. The absolute risk of glucocorticoid-associated osteonecrosis in the general paediatric population and in adults taking low glucocorticoid doses is at most extremely small.

Skeletal Fragility in Children with Chronic Disease

Skeletal fragility associated with underlying childhood chronic disease is a systemic disorder of poor bone growth and reduction in bone turnover which can lead to abnormal bone mass, geometry and microarchitecture. Due to the growth potential unique to children, remarkable bone recovery following a transient threat to the bone can occur if there is concurrent growth. Addressing bone health in these children should focus on improvement in growth, puberty and removing the primary insult. In conditions where there is a little scope for bone recovery and limited residual growth, bone-targeted therapy may need to be considered, even though there is currently limited evidence. The importance of early detection of signs of bone fragility, by active screening for vertebral fracture using newer imaging techniques such as dual-energy X-ray absorptiometry lateral vertebral morphometry, may now be possible. There is currently, a paucity of evidence to support prophylactic use of anti-resorptive therapy. Where poor growth and low bone turnover are seen, the use of growth-promoting therapies and anabolic bone-protective agents may be more physiological and should be evaluated in well-designed trials. Collaborative studies on long-term fracture outcome and well-designed trials of bone-protective therapies are needed and to be encouraged.

Trabecular and cortical bone deficits are present in children and adolescents with cystic fibrosis

Osteopenia and increased fracture rates are well-recognized in adults with CF, but neither the specific contributions of cortical and trabecular bone deficits to bone fragility nor their presence in youth with CF are well-characterized. This study sought to characterize cortical and trabecular volumetric bone mineral density (vBMD), geometry, and biomechanical competence in children with CF and determine their relationship to growth, body composition, and disease severity. Peripheral quantitative computerized tomography (pQCT) measures of total, cortical, and trabecular vBMD, cortical, muscle, and fat cross-sectional areas (CSA), periosteal and endosteal circumferences, and the polar unweighted section modulus (Zp) of the tibia were converted to age- and tibial length-adjusted Z-scores in 97 CF and 199 healthy children (aged 8-21y). Effects of body composition and pulmonary function (forced expiratory volume in 1s, FEV1) upon pQCT outcomes were determined using linear regression. Children with CF (FEV1%-predicted: 84.4+19.7) had lower weight-, height-, BMI-, and whole body lean mass (LBM)-Z and tibial length. Females with CF had lower (p<0.01) total and trabecular vBMD; cortical, muscle, and fat CSA; Zp and periosteal circumference than females in the healthy reference group. These bone differences persisted after adjustment for BMI-Z and to a great extent following adjustment for muscle CSA. Males with CF had lower (p<0.01) cortical, muscle, and fat CSA and their trabecular vBMD deficit approached significance (p=0.069). Deficits were attenuated by adjustment for BMI-Z and to a greater extent adjustment for muscle CSA-Z. The relationship between FEV1%-predicted and pQCT outcomes persisted only in males following adjustment for age and BMI-Z. The CF cohort had lower tibial muscle CSA than expected for their LBM. In this relatively healthy, young CF cohort, deficits in trabecular and multiple cortical bone parameters were present. In females, deficits were greater at older ages and were not fully explained by alterations in body composition. In males worsening pulmonary function was associated with greater deficits that was not explained by increasing age or compromised nutritional status. The occurrence of these differences in CF youth highlights the importance of instituting measures to optimize peak bone mass early in the course of CF.

ABCD: Anthropometry, Body Composition, and Crohn Disease

BACKGROUND

Young individuals with Crohn disease (CD) are at risk of poor bone mineral density (BMD) and reduced lean tissue mass (LTM). The importance of LTM for maintaining skeletal health, in both incident and established CD, is evidenced. We used dual-energy x-ray absorptiometry assessment to identify areal BMD and LTM in individuals with CD.

METHODS

In 57 patients with CD (15F; 12.99-14.16 years) anthropometric, disease activity, bone age assessment, and total body dual-energy x-ray absorptiometry measurements were acquired. A 4-step algorithm was used to assess simultaneous bone and body composition data: areal BMD and height z scores, and LTM for height and bone mineral content (BMC) for LTM z scores were calculated. Low z score cut-off values were defined as ≤1 standard deviations below the population means.

RESULTS

The CD cohort showed: low areal BMD z scores (P = 0.00); and low LTM for height (P = 0.00) according to defined cut-off values. BMC appeared to be adapting for the lower amount of LTM. Correcting for bone age eliminated the low areal BMD z scores. As expected, LTM for height and BMC for LTM z scores remained unchanged.

CONCLUSIONS

We present a useful clinical algorithm to show significant LTM for height deficits, regardless of chronological or bone age, in this CD cohort. BMC seemed to adapt to the reduced LTM, indicating clinically "normal" areal BMD for age when considered for height. The ongoing deficits in LTM may, however, create chronic long-term consequences for bone health. Improving LTM should be a focus of clinical treatment in individuals with CD.

Effect of Low-Magnitude Mechanical Stimuli on Bone Density and Structure in Pediatric Crohn's Disease: A Randomized Placebo-Controlled Trial

Pediatric Crohn's Disease (CD) is associated with low trabecular bone mineral density (BMD), cortical area, and muscle mass. Low-magnitude mechanical stimulation (LMMS) may be anabolic. We conducted a 12-month randomized double-blind placebo-controlled trial of 10 minutes daily exposure to LMMS (30 Hz frequency, 0.3 g peak-to-peak acceleration). The primary outcomes were tibia trabecular BMD and cortical area by peripheral quantitative CT (pQCT) and vertebral trabecular BMD by QCT; additional outcomes included dual-energy X-ray absorptiometry (DXA) whole body, hip and spine BMD, and leg lean mass. Results were expressed as sex-specific Z-scores relative to age. CD participants, ages 8 to 21 years with tibia trabecular BMD <25th percentile for age, were eligible and received daily cholecalciferol (800 IU) and calcium (1000 mg). In total, 138 enrolled (48% male), and 121 (61 active, 60 placebo) completed the 12-month trial. Median adherence measured with an electronic monitor was 79% and did not differ between arms. By intention-to-treat analysis, LMMS had no significant effect on pQCT or DXA outcomes. The mean change in spine QCT trabecular BMD Z-score was +0.22 in the active arm and -0.02 in the placebo arm (difference in change 0.24 [95% CI 0.04, 0.44]; p = 0.02). Among those with >50% adherence, the effect was 0.38 (95% CI 0.17, 0.58, p < 0.0005). Within the active arm, each 10% greater adherence was associated with a 0.06 (95% CI 0.01, 1.17, p = 0.03) greater increase in spine QCT BMD Z-score. Treatment response did not vary according to baseline body mass index (BMI) Z-score, pubertal status, CD severity, or concurrent glucocorticoid or biologic medications. In all participants combined, height, pQCT trabecular BMD, and cortical area and DXA outcomes improved significantly. In conclusion, LMMS was associated with increases in vertebral trabecular BMD by QCT; however, no effects were observed at DXA or pQCT sites. © 2016 American Society for Bone and Mineral Research.

Hepatitis C virus coinfection as a risk factor for osteoporosis and fracture

PURPOSE OF REVIEW

With increased survival of HIV-infected patients, osteoporotic fractures have developed as a major cause of morbidity in these patients, and chronic hepatitis C virus (HCV) coinfection has emerged as a significant contributor to this increased fracture risk. The present article reviews the epidemiologic and clinical evidence for osteoporosis and increased fracture risk among HIV/HCV coinfected patients, and potential mechanisms for these outcomes with HCV coinfection.

RECENT FINDINGS

Epidemiologic studies suggest that HIV/HCV coinfected patients exhibit a three-fold increased fracture incidence compared with uninfected controls, and 1.2-2.4-fold increased fracture risk compared with HIV monoinfected patients. Recent reports suggest that chronic HCV coinfection is independently associated with reduced bone mineral density in HIV, but that it is not associated with significantly increased bone turnover. The deleterious impact of chronic HCV on BMD and fracture risk occurs even in the absence of advanced liver fibrosis or cirrhosis. New tools to assess bone quality, including the trabecular bone score, high-resolution peripheral quantitative computed tomography, and in-vivo microindentation, may help improve understanding of the mechanisms of HCV-associated skeletal fragility. The impact of approved antiosteoporosis medications and direct-acting antivirals for the treatment of chronic HCV infection on patients' bone health remain to be studied.

SUMMARY

Chronic HCV infection is an independent risk factor for osteoporosis and fractures among HIV-infected patients, even before the development of cirrhosis. The underlying mechanisms are being unraveled, but major questions persist regarding the optimal evaluation and management of bone health in HIV/HCV coinfected patients.

Body composition estimation using skinfolds in children with and without health conditions affecting growth and body composition

BACKGROUND

Body composition prediction equations using skinfolds are useful alternatives to advanced techniques, but their utility across diverse paediatric populations is unknown.

AIM

To evaluate published and new prediction equations across diverse samples of children with health conditions affecting growth and body composition.

SUBJECTS AND METHODS

Anthropometric and dual-energy X-ray absorptiometry (DXA) body composition measures were obtained in children with Down syndrome (n = 59), Crohn disease (n = 128), steroid-sensitive nephrotic syndrome (n = 67) and a healthy reference group (n = 835). Published body composition equations were evaluated. New equations were developed for ages 3-21 years using the healthy reference sample and validated in other groups and national survey data.

RESULTS

Fat mass (FM), fat-free mass (FFM) and percentage body fat (%BF) from published equations were highly correlated with DXA-derived measures (r = 0.71-0.98), but with poor agreement (mean difference = 2.4 kg, -1.9 kg and 6.3% for FM, FFM and %BF). New equations produced similar correlations (r = 0.85-1.0) with improved agreement for the reference group (0.2 kg, 0.4 kg and 0.0% for FM, FFM and %BF, respectively) and in sub-groups.

CONCLUSIONS

New body composition prediction equations show excellent agreement with DXA and improve body composition estimation in healthy children and those with selected conditions affecting growth.

Proceedings of the 2015 Santa Fe Bone Symposium: Clinical Applications of Scientific Advances in Osteoporosis and Metabolic Bone Disease

The 2015 Santa Fe Bone Symposium was a venue for healthcare professionals and clinical researchers to present and discuss the clinical relevance of recent advances in the science of skeletal disorders, with a focus on osteoporosis and metabolic bone disease. Symposium topics included new developments in the translation of basic bone science to improved patient care, osteoporosis treatment duration, pediatric bone disease, update of fracture risk assessment, cancer treatment-related bone loss, fracture liaison services, a review of the most significant studies of the past year, and the use of telementoring with Bone Health Extension for Community Healthcare Outcomes, a force multiplier to improve the care of osteoporosis in underserved communities.

Deficits in bone density and structure in children and young adults following Fontan palliation

BACKGROUND

Survival of patients with congenital heart disease has improved such that there are now more adults than children living with these conditions. Complex single ventricle congenital heart disease requiring Fontan palliation is associated with multiple risk factors for impaired bone accrual. Bone density and structure have not been characterized in these patients.

METHODS

Tibia peripheral quantitative computed tomography (pQCT) was used to assess trabecular and cortical volumetric bone mineral density (vBMD), cortical dimensions, and calf muscle area in 43 Fontan participants (5-33 years old), a median of 10 years following Fontan palliation. pQCT outcomes were converted to sex- and race-specific Z-scores relative to age based on >700 healthy reference participants. Cortical dimensions and muscle area were further adjusted for tibia length.

RESULTS

Height Z-scores were lower in Fontan compared to reference participants (mean ± SD: -0.29 ± 1.00 vs. 0.25 ± 0.93, p < 0.001); BMI Z-scores were similar (0.16 ± 0.88 vs. 0.35 ± 1.02, p = 0.1). Fontan participants had lower trabecular vBMD Z-scores (-0.85 ± 0.96 vs. 0.01 ± 1.02, p < 0.001); cortical vBMD Z-scores were similar (-0.17 ± 0.98 vs. 0.00 ± 1.00, p = 0.27). Cortical dimensions were reduced with lower cortical area (-0.59 ± 0.84 vs. 0.00 ± 0.88, p<0.001) and periosteal circumference (-0.50 ± 0.82 vs. 0.00 ± 0.84, p < 0.001) Z-scores, compared to reference participants. Calf muscle area Z-scores were lower in the Fontan participants (-0.45 ± 0.98 vs. 0.00 ± 0.96, p = 0.003) and lower calf muscle area Z-scores were associated with smaller periosteal circumference Z-scores (R = 0.62, p < 0.001). Musculoskeletal deficits were not associated with age, Fontan characteristics, parathyroid hormone or vitamin D levels.

CONCLUSIONS

Children and young adults demonstrate low trabecular vBMD, cortical structure and muscle area following Fontan. Muscle deficits were associated with smaller periosteal dimensions. Future studies should determine the fracture implications of these deficits and identify interventions to promote musculoskeletal development.

Seasonal variability of vitamin D and bone metabolism in infliximab-treated paediatric Crohn's disease

BACKGROUND

Paediatric Crohn's disease patients suffer from several complications, including low bone mineral density and inadequate serum levels of 25-hydroxy vitamin D.

AIMS

The aim of this prospective study was to address the effect of infliximab therapy on bone metabolism, bone mineral density and vitamin D homeostasis. The seasonal variability of serum vitamin D levels in relation to infliximab treatment was also analysed.

METHODS

Serum osteocalcin and beta-crosslaps (markers of bone metabolism), seasonal variability of vitamin D, and bone mineral density were assessed and followed throughout the yearlong treatment regimen of infliximab in 50 consecutive paediatric patients with moderate to severe Crohn's disease.

RESULTS

Bone forming osteocalcin levels were significantly (p<0.001) increased during infliximab therapy. In contrast, no significant changes in beta-crosslaps and vitamin D levels were observed. Vitamin D levels were significantly different when the summer and winter periods were compared at week 0 (p=0.039); however, this difference was not detected after one year of infliximab therapy. Despite the beneficial clinical effect of infliximab, there was no significant change in bone mineral density Z-scores after one year of treatment.

CONCLUSION

Infliximab may beneficially affect bone homeostasis. Moreover, seasonal variability in vitamin D levels observed prior to initiation of infliximab treatment was diminished after one year of treatment.

Fractures on bisphosphonates in osteoporosis pseudoglioma syndrome (OPPG): pQCT shows poor bone density and structure

Osteoporosis pseudoglioma syndrome (OPPG) is a rare autosomal recessive disorder of childhood osteoporosis and blindness due to inactivating mutations in LDL receptor-like protein 5 (LRP5). We and others have reported improvement in areal bone mineral density (aBMD) by DXA in OPPG on short term bisphosphonates. Long-term data on bisphosphonate use in OPPG and measures of volumetric BMD (vBMD) and cortical structure are not available. In addition, no long-term DXA data on untreated OPPG is available. The aims of this study were to: (1) record low trauma fractures and longitudinal aBMD by DXA in 5 OPPG patients on chronic bisphosphonate treatment, and in 4 OPPG patients never treated (2) to perform tibia peripheral quantitative CT (pQCT) to evaluate volumetric bone mineral density (vBMD), cortical structure and calf muscle area in 6 OPPG patients and 14 unaffected first degree family members. pQCT results were converted to sex-specific Z-scores for age and adjusted for tibia length based on data in >700 reference participants. We observed 4 fractures (3 femoral shafts) in 3 OPPG patients while on bisphosphonates, after each achieved significant improvement in aBMD. OPPG participants had significantly lower mean trabecular vBMD (-1.51 vs. 0.17, p = 0.002), cortical area (-2.36 vs. 0.37; p < 0.001) and periosteal circumference (-1.86 vs. -0.31, p = 0.001) Z-scores, compared with unaffected participants and had a trend toward lower muscle area Z-score (-0.69 vs. 0.47, p = 0.12). These data demonstrate substantial bone fragility despite improvements in aBMD. The pQCT data provide insight into the fragility with substantial deficits in trabecular vBMD and cortical dimensions, consistent with OPPG effects of bone formation. Treatment that improves bone quality is needed to reduce fractures in OPPG.

Improvements in Bone Density and Structure during Anti-TNF-α Therapy in Pediatric Crohn's Disease

CONTEXT

Pediatric Crohn's Disease (CD) is associated with deficits in trabecular bone mineral density (BMD) and cortical structure, potentially related to TNF-α effects to decrease bone formation and promote bone resorption.

OBJECTIVE

This study aimed to examine changes in bone density and structure in children and adolescents with CD following initiation of anti-TNF-α therapy.

DESIGN AND PARTICIPANTS

Participants (n = 74; age 5-21 years) with CD completed a 12-month prospective cohort study.

MAIN OUTCOME MEASURES

Tibia peripheral quantitative computed tomography scans were obtained at initiation of anti-TNF-α therapy and 12 months later. Musculoskeletal outcomes were expressed as sex-and race-specific z scores relative to age, based on >650 reference participants.

RESULTS

At baseline, CD participants had lower height, trabecular BMD, cortical area (due to smaller periosteal and larger endocortical circumferences), and muscle area z scores, compared with reference participants (all P < .01). Pediatric CD activity index decreased during the 10-week induction (P < .001), in association with subsequent gains in height, trabecular BMD, cortical area (due to recovery of endocortical bone), and muscle area z scores over 12 months (height P < .05; others P < .001). Bone-specific alkaline phosphatase levels, a biomarker of bone formation, increased a median of 75% (P < .001) during induction with associated 12-month improvements in trabecular BMD and cortical area z scores (both P < .001). Younger age was associated with greater increases in trabecular BMD z scores (P < .001) and greater linear growth with greater recovery of cortical area (P < .001).

CONCLUSIONS

Anti-TNF-α therapy was associated with improvements in trabecular BMD and cortical structure. Improvements were greater in younger and growing participants, suggesting a window of opportunity for treatment of bone deficits.

Short-Term Efficacy of Exclusive Enteral Nutrition in Pediatric Crohn's Disease: Practice in China

Aims. The objective of this study was to compare the efficacy of exclusive enteral nutrition (EEN) and corticosteroids in inducing remission in pediatric Crohn's disease (CD) and the effects of the treatment on growth improvements. Methods. Data was retrospectively collected for children and adolescents newly diagnosed with CD in a referral center. Patients who were followed up for more than 2 months with mild to moderate disease were included. Basic demographics, history, physical examination, the pediatric Crohn disease activity index (PCDAI), laboratory findings, endoscopic findings, and adverse effects were recorded. Remission was defined as PCDAI < 10 points. Results. Ten subjects received EEN and 18 patients received corticosteroids. The median follow-up in EEN group and steroid group was 9.2 weeks and 9.6 weeks, respectively. The remission rate in EEN group was significantly higher than that in steroid group (90.0% versus 50.0%, resp., P < 0.05). Growth improvement, which was evaluated by changes in height for age z-score, was more apparent in EEN group than that in steroids group (P < 0.05). No adverse effects were observed in EEN group. Conclusions. In children with mild to moderate CD, EEN is more effective than corticosteroids in improving disease severity and growth deficiency, as well as providing less side effects.

Structural Bone Deficits in HIV/HCV-Coinfected, HCV-Monoinfected, and HIV-Monoinfected Women

BACKGROUND

Coinfection with human immunodeficiency virus (HIV) and hepatitis C virus (HCV) is associated with reduced bone mineral density (BMD) and increased fracture rates, particularly in women. The structural underpinnings for skeletal fragility in coinfected women have not been characterized. We used tibial peripheral quantitative computed tomography to evaluate skeletal parameters in women, by HIV/HCV status.

METHODS

We conducted a cross-sectional study among 50 HIV/HCV-coinfected, 51 HCV-monoinfected, and 50 HIV-monoinfected women. Tibial volumetric BMD and cortical dimensions were determined with peripheral quantitative computed tomography. Race-specific z scores for age were generated using 263 female reference participants without HIV infection or liver disease.

RESULTS

Coinfected participants had lower mean z scores for trabecular volumetric BMD (-0.85), cortical volumetric BMD (-0.67), cortical area (-0.61), and cortical thickness (-0.77) than reference participants (all P < .001). The smaller cortical dimensions were due to greater mean z scores for endosteal circumference (+0.67; P < .001) and comparable z scores for periosteal circumference (+0.04; P = .87). Trabecular volumetric BMD was lower in coinfected than in HCV- or HIV-monoinfected participants. HCV-infected women with stage 3-4 liver fibrosis had lower mean z scores for trabecular volumetric BMD, cortical thickness, and total hip BMD those with stage 0-2 fibrosis.

CONCLUSIONS

Compared with healthy reference patients, HIV/HCV-coinfected women had decreased tibial trabecular volumetric BMD, diminished cortical dimensions, and significant endocortical bone loss.

Muscle torque relative to cross-sectional area and the functional muscle-bone unit in children and adolescents with chronic disease

Measures of muscle mass or size are often used as surrogates of forces acting on bone. However, chronic diseases may be associated with abnormal muscle force relative to muscle size. The muscle-bone unit was examined in 64 children and adolescents with new-onset Crohn's disease (CD), 54 with chronic kidney disease (CKD), 51 treated with glucocorticoids for nephrotic syndrome (NS), and 264 healthy controls. Muscle torque was assessed by isometric ankle dynamometry. Calf muscle cross-sectional area (CSA) and tibia cortical section modulus (Zp) were assessed by quantitative CT. Log-linear regression was used to determine the relations among muscle CSA, muscle torque, and Zp, adjusted for tibia length, age, Tanner stage, sex, and race. Muscle CSA and muscle torque-relative-to-muscle CSA were significantly lower than controls in advanced CKD (CSA -8.7%, p = 0.01; torque -22.9%, p < 0.001) and moderate-to-severe CD (CSA -14.1%, p < 0.001; torque -7.6%, p = 0.05), but not in NS. Zp was 11.5% lower in advanced CKD (p = 0.005) compared to controls, and this deficit was attenuated to 6.7% (p = 0.05) with adjustment for muscle CSA. With additional adjustment for muscle torque and body weight, Zp was 5.9% lower and the difference with controls was no longer significant (p = 0.09). In participants with moderate-to-severe CD, Zp was 6.8% greater than predicted (p = 0.01) given muscle CSA and torque deficits (R(2)  = 0.92), likely due to acute muscle loss in newly-diagnosed patients. Zp did not differ in NS, compared with controls. In conclusion, muscle torque relative to muscle CSA was significantly lower in CKD and CD, compared with controls, and was independently associated with Zp. Future studies are needed to determine if abnormal muscle strength contributes to progressive bone deficits in chronic disease, independent of muscle area. © 2014 American Society for Bone and Mineral Research.

Piroxicam treatment augments bone abnormalities in interleukin-10 knockout mice

BACKGROUND

Osteoporosis and fractures are common complications of inflammatory bowel disease. The pathogenesis is multifactorial and has been partly attributed to intestinal inflammation. The aim of this study was to evaluate bone status and assess the association between bone loss and gut inflammation in an experimental colitis model.

METHODS

Colitis was induced in interleukin-10 knockout mice (PAC IL-10 k.o.) by peroral administration of piroxicam for 12 days. The degree of colitis was assessed by clinical, macroscopic, and microscopic evaluation. Trabecular and cortical bone microarchitecture of tibia were determined using micro-computed tomography. Moreover, the serum levels of bone formation and bone resorption biomarkers were measured, and inflammatory protein profiling was performed on colons.

RESULTS

PAC IL-10 k.o. mice developed severe colitis, characterized by hyperplasia and focal transmural inflammation, which was consistent with Crohn's disease-like pathology. The gut inflammation was accompanied by a 14% and 12% reduction in trabecular thickness relative to piroxicam-treated wild type and untreated wild type mice, respectively (P < 0.001). The trabecular bone structure was also changed in PAC IL-10 k.o. mice, whereas no differences in cortical bone geometry were observed. The trabecular thickness was inversely correlated with serum levels of CTX (r = -0.93, P = 0.006). Moreover, numerous inflammatory mediators, including RANKL and osteoprotegerin, were significantly increased in the colon of PAC IL-10 k.o. mice.

CONCLUSIONS

PAC IL-10 k.o. mice develop bone loss and changed trabecular structure, as a result of increased bone resorption. Thus, the PAC IL-10 k.o. model could be a useful experimental model in preclinical research of inflammatory bowel disease-associated bone loss.

Crohn's disease and growth deficiency in children and adolescents

Nutritional concerns, linear growth deficiency, and delayed puberty are currently detected in up to 85% of patients with Crohn’s disease (CD) diagnosed at childhood. To provide advice on how to assess and manage nutritional concerns in these patients, a Medline search was conducted using “pediatric inflammatory bowel disease”, “pediatric Crohn’s disease”, “linear growth”, “pubertal growth”, “bone health”, and “vitamin D” as key words. Clinical trials, systematic reviews, and meta-analyses published between 2008 and 2013 were selected to produce this narrative review. Studies referring to earlier periods were also considered if the data was relevant to our review. Although current treatment strategies for CD that include anti-tumor necrosis factor-α therapy have been shown to improve patients’ growth rate, linear growth deficiencies are still common. In pediatric CD patients, prolonged diagnostic delay, high initial activity index, and stricturing/penetrating type of behavior may cause growth deficiencies (in weight and height) and delayed puberty, with several studies reporting that these patients may not reach an optimal bone mass. Glucocorticoids and inflammation inhibit bone formation, though their impact on skeletal modeling remains unclear. Long-term control of active inflammation and an adequate intake of nutrients are both fundamental in promoting normal puberty. Recent evidence suggests that recombinant growth factor therapy is effective in improving short-term linear growth in selected patients, but is of limited benefit for ameliorating mucosal disease and reducing clinical disease activity. The authors conclude that an intense initial treatment (taking a “top-down” approach, with the early introduction of immunomodulatory treatment) may be justified to induce and maintain remission so that the growth of children with CD can catch up, ideally before puberty. Exclusive enteral nutrition has a key role in inducing remission and improving patients’ nutritional status.

Pathological fractures in paediatric patients with inflammatory bowel disease

Paediatric inflammatory bowel disease (IBD), especially Crohn's disease (CD), is commonly associated with poor skeletal health, related to the direct effects of chronic inflammation, prolonged use of glucocorticoid (GC), poor nutrition, delayed puberty and low muscle mass. Low bone mineral density is commonly reported, although the prevalence of long bone fractures may not be increased in these patients. Emerging evidence however suggests that there may be an increased risk of vertebral fractures (VFs) in this group. VFs presenting at diagnosis of paediatric CD, prior to any GC exposure, have been reported, highlighting the deleterious effect of inflammation on skeletal health. This paper reviews the published literature on pathophysiology of skeletal morbidity and fractures in paediatric IBD, illustrated with a new case report of multiple VFs in a prepubertal girl with CD, soon after diagnosis, who received minimal amounts of oral GC. Optimising control of disease, addressing vitamin D deficiency, encouraging physical activity and ensuring normal growth and pubertal progression are paramount to management of bone health in these patients. Despite the lack of evidence, there may be a place for bisphosphonate treatment, especially in the presence of symptomatic pathological fractures, but this requires close monitoring by clinicians with expertise in paediatric bone health.

CONCLUSION

Chronic inflammation mediated by pro-inflammatory cytokines may have adverse effects on skeletal health in paediatric patients with IBD. The risk of vertebral fractures may be increased, even without exposure to glucocorticoid. Clinical monitoring of these patients requires careful attention to the various factors that impact on bone health.