IBD and skeletal health: children are not small adults!

Impact of an exercise program in children with inflammatory bowel disease in remission

BACKGROUND

The aim of our study was to investigate the impact of a structured exercise program on bone mineral density (BMD) and body composition parameters in children and adolescents with IBD in remission.

METHODS

Patients were recruited to participate in a 6-month exercise program. Total body less head (TLBH) dual energy X-ray absorptiometry (DXA) was used to measure BMD. The same method was used to assess fat mass (FM) and lean body mass (LBM) at baseline and at the completion of the program.

RESULTS

Based on the baseline and endpoint TBLH DXA measurements, a total of 42 study participants (25 boys; aged 15.3 ± 2.08 years) experienced an increase in BMD (from 0.959 ± 0.023 g/cm² to 0.988 ± 0.025 g/cm², p < 0.001) and LBM (from 37.12 ± 1.43 kg to 38.75 ± 1.61 kg, p = 0.012). Age- and sex-based BMD Z-score increased significantly (from -0.35 ± 0.15 to -0.28 ± 0.17, p = 0.020), whilst LBM Z-score did not significantly change (from -1.78 ± 0.23 to -1.71 ± 1.49, p = 0.908).

CONCLUSIONS

There was a significant improvement in BMD, age- and sex-based BMD Z-score, and LBM amongst study participants. Subgroup analysis showed that patients with CD and male study participants experienced significant improvement in all parameters, whilst patients with UC and IBD-U and female patients experienced improvement solely in BMD.

IMPACT STATEMENT

Children and adolescents with IBD, regardless of disease activity, are under increased risk of secondary osteoporosis and lean body mass deficits. A 6-month home-based structured exercise program leads to a significant improvement in bone mineral density and lean body mass. Exercise therapy should be explored as a potentially adjacent to standard treatment modalities.

Moderate-to-Vigorous Physical Activity Is Associated With Higher Bone Mineral Density in Children With Inflammatory Bowel Disease

OBJECTIVES

Decreased mineral bone density (BMD) and reduced lean body mass (LBM) are common amongst children with inflammatory bowel disease (IBD). The aim of our cross-sectional, observational study was to evaluate the relationship between BMD, body composition and physical activity (PA) in children with IBD in remission.

METHODS

Total body less head (TLBH) dual energy X-ray absorptiometry (DXA) was used to measure BMD, fat mass (FM) and lean body mass (LBM). Triaxial accelerometer for five consecutive days was used to objectivize PA.

RESULTS

Forty pediatric IBD patients in clinical remission (24 boys; age 15.3 ± 0.4 years; Crohn disease [CD], n = 20, ulcerative colitis [UC], n = 18, inflammatory bowel disease-unclassified [IBD-U], n = 2) were recruited. Mean BMD was 0.940 g/cm2 and mean BMD z score was -0.42 ± 0.14. Patients with CD had significantly lower BMD than UC counterparts (P < 0.001). Average time spent in PA was 247.24 ± 16.71 min/day with 45.73 ± 8.22 min/day spent in moderate-to-vigorous PA (MVPA). We observed a significant positive correlation between the time spent in MVPA and BMD z score (P = 0.003) and LBM z score (P = 0.026). Multivariate analysis confirmed that the positive correlation of MVPA and BMD z score. There was no significant correlation between daily protein intake and BMD. Cumulative glucocorticoid dose negatively correlated with LBM z score (P = 0.003), but not with BMD z score (P = 0.069).

CONCLUSIONS

This study points to a strong positive relationship between MVPA, LBM and BMD. Longitudinal studies are required in order to elucidate the modifiable processes that determine body health and favorable body composition.

Medications as a Risk Factor for Fragility Hip Fractures: A Systematic Review and Meta-analysis

Fragility hip fractures and their associated morbidity and mortality pose a global healthcare problem. Several pharmaceutical products have been postulated to alter bone architecture and contribute to fragility hip fractures. We searched four electronic databases from inception to September 2017. Inclusion criteria were the following: (1) adult patients with fragility hip fractures, (2) full text in English, (3) minimum one-year follow-up, and (4) reporting of at least one risk factor. To minimize heterogeneity among the studies, we performed subgroup analyses. Whenever heterogeneity remained significant, we employed random effect meta-analysis for data pooling. Thirty-eight studies were included, containing 1,244,155 subjects and 188,966 cases of fragility hip fractures. Following medications were significantly associated with fragility hip fractures: Antidepressants (OR 2.07, 95% CI 1.98-2.17), antiparkinsonian drugs (OR 2.21, 95% CI 1.15-4.24), antipsychotic drugs (OR 2.0, 95% CI 1.50-2.66), anxiolytic drugs (OR 1.44, 95% CI 1.19-1.75), benzodiazepines (OR 1.84, 95% CI 1.26-2.69), sedatives (OR 1.33, 95% CI 1.14-1.54), systemic corticosteroids (OR 1.65, 95% CI 1.37-1.99), H₂ antagonists (OR 1.21, 95% CI 1.18-1.24), proton pump inhibitors (OR 1.41, 95% CI 1.16-1.71), and thyroid hormone (OR 1.29, 95% CI 1.13-1.47). Hormone replacement therapy with estrogen (HRT) was associated with decreased risk of hip fracture (OR 0.80, 95% CI 0.65-0.98). There are several medications associated with sustaining a fragility hip fracture. Medical interventions should be considered for patients on these medications, including information about osteoporosis and fracture prevention.

Vitamin D therapy in children with inflammatory bowel disease: A systematic review

BACKGROUND

Vitamin D deficiency is highly prevalent in children with inflammatory bowel disease (IBD). This may contribute to an increased risk of poor bone health and may also influence the course of disease. An optimal treatment strategy of vitamin D therapy in children with IBD has not yet been established.

AIM

To analyse the published intervention studies of vitamin D therapy in children with IBD.

METHODS

A systematic review was conducted of clinical studies involving children with IBD (including Crohn disease or ulcerative colitis) who had received vitamin D therapy. Studies up to March 31^st 2018 were identified through MEDLINE, PubMed, EMBASE and the Cochrane Library. Search terms included synonyms of the following terms: vitamin D, paediatric, supplementation, IBD. References of included articles based on abstract were searched for other relevant articles. All relevant articles were accessed and reviewed in full text. Studies fitting the set criteria were included and the remainder were excluded.

RESULTS

Two hundred and seventy-seven discrete articles were identified. Following assessment of these articles included in the initial search and application of inclusion and exclusion criteria, ten published studies were included in this review. The included studies showed a heterogeneity in study design, inclusion and exclusion criteria, baseline demographics and treatment strategies. Treatment regimens differed in length, supplemented form of vitamin D and factors based upon which dosage was adjusted. Each of the reports included in this review concluded their vitamin D regimens to be safe and well-tolerated. Few of the included studies reported secondary outcomes on the efficacy of vitamin D treatment upon the clinical course of disease or markers of inflammation. The majority of included trials were not sufficient in raising serum vitamin D levels to an adequate level (30 ng/mL) in children with IBD with vitamin D deficiency.

CONCLUSION

The included trials featured diverse treatment regimens that were predominantly insufficient in correcting vitamin D deficiency or maintaining adequate levels in children with IBD. Better treatment regimens are required for the management of vitamin D deficiency in children with IBD.

High Molecular Weight Polymer Promotes Bone Health and Prevents Bone Loss Under Salmonella Challenge in Broiler Chickens

As a consequence of rapid growth, broiler chickens are more susceptible to infection as well as bone fractures that result in birds being culled. Intestinal infection/inflammation has been demonstrated to promote bone loss in mice and humans. Given this link, we hypothesize that therapeutics that target the gut can benefit bone health. To test this, we infected broiler chickens (7 days old) with Salmonella and treated the birds with or without MDY, a non-absorbable mucus supplement known to benefit intestinal health, from day 1–21 or from day 14–21. Chicken femoral trabecular and cortical bone parameters were analyzed by microcomputed tomography at 21 days. Birds infected with Salmonella displayed significant trabecular bone loss and bone microarchitecture abnormalities that were specific to the femoral neck region, a common site of fracture in chickens. Histological analyses of the chicken bone indicated an increase in osteoclast surface/bone surface in this area indicating that infection-induced bone resorption likely causes the bone loss. Of great interest, treatment with MDY effectively prevented broiler chicken bone loss and architectural changes when given chronically throughout the experiment or for only a week after infection. The latter suggests that MDY may not only prevent bone loss but reverse bone loss. MDY also increased cortical bone mineral density in Salmonella-treated chickens. Taken together, our studies demonstrate that Salmonella-induced bone loss in broiler chickens is prevented by oral MDY.

Intestinal inflammation without weight loss decreases bone density and growth

Increasing evidence indicates a strong link between intestinal health and bone health. For example, inflammatory bowel disease can cause systemic inflammation, weight loss, and extra-intestinal manifestations, such as decreased bone growth and density. However, the effects of moderate intestinal inflammation without weight loss on bone health have never been directly examined; yet this condition is relevant not only to IBD but to conditions of increased intestinal permeability and inflammation, as seen with ingestion of high-fat diets, intestinal dysbiosis, irritable bowel syndrome, metabolic syndrome, and food allergies. Here, we induced moderate intestinal inflammation without weight loss in young male mice by treating with a low dose of dextran sodium sulfate (1%) for 15 days. The mice displayed systemic changes marked by significant bone loss and a redistribution of fat from subcutaneous to visceral fat pad stores. Bone loss was caused by reduced osteoblast activity, characterized by decreased expression of osteoblast markers (runx2, osteocalcin), histomorphometry, and dynamic measures of bone formation. In addition, we observed a reduction in growth plate thickness and hypertrophic chondrocyte matrix components (collagen X). Correlation analyses indicate a link between gut inflammation and disease score, but more importantly, we observed that bone density measures negatively correlated with intestinal disease score, as well as colon and bone TNF-α levels. These studies demonstrate that colitis-induced bone loss is not dependent upon weight loss and support a role for inflammation in the link between gut and bone health, an important area for future therapeutic 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.

Update in pediatric inflammatory bowel disease

The incidence of inflammatory bowel disease (IBD), Crohn's disease and ulcerative colitis, in children is on the rise. Pediatric patients with IBD are especially vulnerable to the physical and psychosocial morbidities of this disorder. Unique aspects of pediatric IBD patients compared to adult patients warrants an individualized approach to management regardless of age. This review focuses on the special aspects of pediatric IBD and the implications for the diagnosis and management of this disease.

Osteoporosis in young adults: pathophysiology, diagnosis, and management

Postmenopausal osteoporosis is mainly caused by increased bone remodeling resulting from estrogen deficiency. Indications for treatment are based on low areal bone mineral density (aBMD, T-score  ≤ -2.5), typical fragility fractures (spine or hip), and more recently, an elevated 10-year fracture probability (by FRAX®). In contrast, there is no clear definition of osteoporosis nor intervention thresholds in younger individuals. Low aBMD in a young adult may reflect a physiologically low peak bone mass, such as in lean but otherwise healthy persons, whereas fractures commonly occur with high-impact trauma, i.e., without bone fragility. Furthermore, low aBMD associated with vitamin D deficiency may be highly prevalent in some regions of the world. Nevertheless, true osteoporosis in the young can occur, which we define as a T-score below -2.5 at spine or hip in association with a chronic disease known to affect bone metabolism. In the absence of secondary causes, the presence of fragility fractures, such as in vertebrae, may point towards genetic or idiopathic osteoporosis. In turn, treatment of the underlying condition may improve bone mass as well. In rare cases, a bone-specific treatment may be indicated, although evidence is scarce for a true benefit on fracture risk. The International Osteoporosis Foundation (IOF) convened a working group to review pathophysiology, diagnosis, and management of osteoporosis in the young, excluding children and adolescents, and provide a screening strategy including laboratory exams for a systematic approach of this condition.

Treatment of vitamin D insufficiency in children and adolescents with inflammatory bowel disease: a randomized clinical trial comparing three regimens

CONTEXT

Vitamin D insufficiency [serum 25-hydroxyvitamin D (25OHD) concentration less than 20 ng/ml] is prevalent among children with inflammatory bowel disease (IBD), and its treatment has not been studied.

OBJECTIVE

The aim of this study was to compare the efficacy and safety of three vitamin D repletion regimens.

DESIGN AND SETTING

We conducted a randomized, controlled clinical trial from November 2007 to June 2010 at the Clinical and Translational Study Unit of Children's Hospital Boston. The study was not blinded to participants and investigators.

PATIENTS

Eligibility criteria included diagnosis of IBD, age 5-21, and serum 25OHD concentration below 20 ng/ml. Seventy-one patients enrolled, 61 completed the trial, and two withdrew due to adverse events.

INTERVENTION

Patients received orally for 6 wk: vitamin D(2), 2,000 IU daily (arm A, control); vitamin D(3), 2,000 IU daily (arm B); vitamin D(2), 50,000 IU weekly (arm C); and an age-appropriate calcium supplement.

MAIN OUTCOME MEASURE

We measured the change in serum 25OHD concentration (Δ25OHD) (ng/ml). Secondary outcomes included change in serum intact PTH concentration (ΔPTH) (pg/ml) and the adverse event occurrence rate.

RESULTS

After 6 wk, Δ25OHD ± se was: 9.3 ± 1.8 (arm A); 16.4 ± 2.0 (arm B); 25.4 ± 2.5 (arm C); P (A vs. C) = 0.0004; P (A vs. B) = 0.03. ΔPTH ± SE was -5.6 ± 5.5 (arm A); -0.1 ± 4.2 (arm B); -4.4 ± 3.9 (arm C); P = 0.57. No participant experienced hypercalcemia or hyperphosphatemia, and the prevalence of hypercalciuria did not differ among arms at follow-up.

CONCLUSIONS

Oral doses of 2,000 IU vitamin D(3) daily and 50,000 IU vitamin D(2) weekly for 6 wk are superior to 2,000 IU vitamin D(2) daily for 6 wk in raising serum 25OHD concentration and are well-tolerated among children and adolescents with IBD. The change in serum PTH concentration did not differ among arms.

Fibroblast growth factor 23 contributes to diminished bone mineral density in childhood inflammatory bowel disease

BACKGROUND

Diminished bone mineral density (BMD) is of significant concern in pediatric inflammatory bowel disease (IBD). Exact etiology is debatable. The recognition of fibroblast growth factor 23 (FGF23), a phosphaturic hormone related to tumor necrosis factor alpha (TNF-α) makes it plausible to hypothesize its possible relation to this pathology.

METHODS

In this follow up case control study, BMD as well as serum levels of FGF23, calcium, phosphorus, alkaline phosphatase, creatinine, parathyroid hormone, 25 hydroxy vitamin D3 and 1, 25 dihydroxy vitamin D3 were measured in 47 children with IBD during flare and reassessed in the next remission.

RESULTS

Low BMD was frequent during IBD flare (87.2%) with significant improvement after remission (44.7%). During disease flare, only 21.3% of patients had vitamin D deficiency, which was severe in 12.8%. During remission, all patients had normal vitamin D except for two patients with Crohn's disease (CD) who remained vitamin D deficient. Mean value of serum FGF23 was significantly higher among patients with IBD during flare compared to controls. It showed significant improvement during remission but not to the control values. 1, 25 dihydroxy vitamin D3, FGF23, serum calcium and urinary phosphorus were significant determinants of BMD in IBD patients.

CONCLUSIONS

We can conclude that diminished BMD in childhood IBD is a common multifactorial problem. Elevated FGF23 would be a novel addition to the list of factors affecting bone mineral density in this context. Further molecular studies are warranted to display the exact interplay of these factors.

Bones in pediatric Crohn's disease: a review of fracture risk in children and adults

There is evidence to suggest that the inflammation associated with Crohn's disease (CD) impacts the bone health of patients, predisposing them to early onset osteoporosis and increasing their risk of fracture. Fractures have been documented in patients with CD, with a high proportion of these being found during young adulthood, which suggests that these patients are not simply fracturing as a result of the normal aging process but rather due to the presence of CD. In population terms, patients with CD have increased risk of fracture compared with the general population. Studies in children suggest that, irrespective of time on corticosteroid therapy, the underlying systemic inflammation associated with CD is an independent detrimental influence on the bone health of children with CD. This poses the question as to whether the onset of disease in childhood predisposes the individual to increased risk of future fractures later in life, as a result of decreased peak bone mass during the growing years. It is generally believed that dual energy x-ray absorptiometry-assessed areal bone mineral density is a good indicator of fracture risk; however, several studies have shown this may not be the case. New research, utilizing peripheral quantitative computed tomography, which provides a true volumetric assessment of bone, suggests altered bone geometry in patients with CD, which poses a structural threat by being more brittle and susceptible to damage accumulation.

Vitamin D deficiency in children with inflammatory bowel disease

BACKGROUND

Osteopenia and osteoporosis are commonly seen in inflammatory bowel disease (IBD). Vitamin D deficiency potentially contributes to diminished bone acquisition in childhood.

OBJECTIVES

The objectives of this study were to assess vitamin D in a group of Australian children with IBD and to ascertain associations between vitamin D status and key clinical factors, for example disease location and severity.

METHODS

Data were obtained retrospectively from the records of children with IBD who had at least one measurement of serum 25-hydroxyvitamin D (25(OH)D) over a two-year period. Demographic variables, disease activity, inflammatory markers, disease location, duration, and therapy were recorded. Moderate and severe deficiency were defined as 25(OH)D <51 nmol/l and <30 nmol/l, respectively. Insufficiency was defined as 25(OH)D between 51 and 75 nmol/l.

RESULTS

Overall, the mean 25(OH)D level in 78 children (104 measurements) was 71.2 (SD ± 26.5) nmol/l. Fifteen (19%) children were vitamin D deficient and 30 (38%) children were insufficient. Levels of 25(OH)D were not associated with disease location or use of immunosuppressive drugs. Children with vitamin D deficiency had greater corticosteroid exposure than those with normal status (P = 0.001). The mean 25(OH)D of 38 children treated with nutritional therapy at diagnosis was higher than for 17 children initially treated with corticosteroids (P = 0.04).

CONCLUSIONS

A high proportion of these Australian children with IBD were vitamin D deficient. This emphasizes the importance of monitoring vitamin D status, and treating deficiency, in the management of pediatric IBD. The possible benefit of nutritional therapy in protection against vitamin D deficiency requires further prospective study.

Advances in the understanding of mineral and bone metabolism in inflammatory bowel diseases

Chronic inflammatory disorders such as inflammatory bowel diseases (IBDs) affect bone metabolism and are frequently associated with the presence of osteopenia, osteoporosis, and increased risk of fractures. Although several mechanisms may contribute to skeletal abnormalities in IBD patients, inflammation and inflammatory mediators such as TNF, IL-1β, and IL-6 may be the most critical. It is not clear whether the changes in bone metabolism leading to decreased mineral density are the result of decreased bone formation, increased bone resorption, or both, with varying results reported in experimental models of IBD and in pediatric and adult IBD patients. New data, including our own, challenge the conventional views, and contributes to the unraveling of an increasingly complex network of interactions leading to the inflammation-associated bone loss. Since nutritional interventions (dietary calcium and vitamin D supplementation) are of limited efficacy in IBD patients, understanding the pathophysiology of osteopenia and osteoporosis in Crohn's disease and ulcerative colitis is critical for the correct choice of available treatments or the development of new targeted therapies. In this review, we discuss current concepts explaining the effects of inflammation, inflammatory mediators and their signaling effectors on calcium and phosphate homeostasis, osteoblast and osteoclast function, and the potential limitations of vitamin D used as an immunomodulator and anabolic hormone in IBD.

Biologic therapy and its effect on skeletal development in children with chronic inflammation

Chronic inflammatory conditions in children such as juvenile idiopathic arthritis, inflammatory bowel disease, cystic fibrosis and systemic lupus erythematosus can cause reduced linear growth, final height and bone mass. There are many mechanisms leading to these skeletal alterations but inflammation itself is considered to play an important role. Biologic therapy is being used increasingly for the treatment of chronic inflammatory conditions and may also be effective in improving growth and skeletal development. The main aim of this article is to summarize the effects of inflammation on growth and skeletal development and evaluate the effects of biologic therapy on growth and skeletal development in children with chronic inflammatory conditions.

Inflammatory bowel disease causes reversible suppression of osteoblast and chondrocyte function in mice

Decreased bone density and stature can occur in pediatric patients with inflammatory bowel disease (IBD). Little is known about how IBD broadly impacts the skeleton. To evaluate the influence of an acute episode of IBD on growing bone, 4-wk-old mice were administered 5% dextran sodium sulfate (DSS) for 5 days to induce colitis and their recovery was monitored. During active disease and early recovery, trabecular bone mineral density, bone volume, and thickness were decreased. Cortical bone thickness, outer perimeter, and density were also decreased, whereas inner perimeter and marrow area were increased. These changes appear to maintain bone strength since measures of moments of inertia were similar between DSS-treated and control mice. Histological (static and dynamic), serum, and RNA analyses indicate that a decrease in osteoblast maturation and function account for changes in bone density. Unlike some conditions of bone loss, marrow adiposity did not increase. Similar to reports in humans, bone length decreased and correlated with decreases in growth plate thickness and chondrocyte marker expression. During disease recovery, mice experienced a growth spurt that led to their achieving final body weights and bone length, density, and gene expression similar to healthy controls. Increased TNF-alpha and decreased IGF-I serum levels were observed with active disease and returned to normal with recovery. Changes in serum TNF-alpha (increased) and IGF-I (decreased) paralleled changes in bone parameters and returned to normal values with recovery, suggesting a potential role in the skeletal response.

Bone health in children with inflammatory bowel disease: adjusting for bone age

OBJECTIVES

Clinical results of bone mineral density for children with inflammatory bowel disease are commonly reported using reference data for chronological age. It is known that these children, particularly those with Crohn disease, experience delayed growth and maturation. Therefore, it is more appropriate to compare clinical results with bone age rather than chronological age.

MATERIALS AND METHODS

Areal bone mineral density (aBMD) was measured using dual energy x-ray absorptiometry, and bone age was assessed using the Tanner-Whitehouse 3 method from a standard hand/wrist radiograph. Results were available for 44 children ages 7.99 to 16.89 years. Areal bone mineral density measurements were converted to z scores using both chronological and bone ages for each subject.

RESULTS

Areal bone mineral density z scores calculated using bone age, as opposed to chronological age, were significantly improved for both the total body and lumbar spine regions of interest. When subjects were grouped according to diagnosis, bone age generated z scores remained significantly improved for those with Crohn disease but not for those diagnosed with ulcerative colitis. Grouping of children with Crohn disease into younger and older ages produced significantly higher z scores using bone age compared with chronological for the older age group, but not the younger age group.

CONCLUSIONS

Our findings, in accordance with those presented in the literature, suggest that aBMD results in children with Crohn disease should include the consideration of bone age, rather than merely chronological age. Bone size, although not as easily available, would also be an important consideration for interpreting results in paediatric populations.

Pharmacologic stem cell based intervention as a new approach to osteoporosis treatment in rodents

BACKGROUND

Osteoporosis is the most prevalent skeletal disorder, characterized by a low bone mineral density (BMD) and bone structural deterioration, leading to bone fragility fractures. Accelerated bone resorption by osteoclasts has been established as a principal mechanism in osteoporosis. However, recent experimental evidences suggest that inappropriate apoptosis of osteoblasts/osteocytes accounts for, at least in part, the imbalance in bone remodeling as occurs in osteoporosis. The aim of this study is to examine whether aspirin, which has been reported as an effective drug improving bone mineral density in human epidemiology studies, regulates the balance between bone resorption and bone formation at stem cell levels.

METHODS AND FINDINGS

We found that T cell-mediated bone marrow mesenchymal stem cell (BMMSC) impairment plays a crucial role in ovariectomized-induced osteoporosis. Ex vivo mechanistic studies revealed that T cell-mediated BMMSC impairment was mainly attributed to the apoptosis of BMMSCs via the Fas/Fas ligand pathway. To explore potential of using pharmacologic stem cell based intervention as an approach for osteoporosis treatment, we selected ovariectomy (OVX)-induced osteoporosis mouse model to examine feasibility and mechanism of aspirin-mediated therapy for osteoporosis. We found that aspirin can inhibit T cell activation and Fas ligand induced BMMSC apoptosis in vitro. Further, we revealed that aspirin increases osteogenesis of BMMSCs by aiming at telomerase activity and inhibits osteoclast activity in OVX mice, leading to ameliorating bone density.

CONCLUSION

Our findings have revealed a novel osteoporosis mechanism in which activated T cells induce BMMSC apoptosis via Fas/Fas ligand pathway and suggested that pharmacologic stem cell based intervention by aspirin may be a new alternative in osteoporosis treatment including activated osteoblasts and inhibited osteoclasts.

Special issues in pediatric inflammatory bowel disease

The incidence of pediatric inflammatory bowel disease (IBD) is rising and recent advances in diagnostics and therapeutics have improved the care provided to these children. There are distinguishing features worth noting between early onset and adult onset IBD. Physical and psychosocial development remains a critical target for the comprehensive management of pediatric IBD. Children are not just little adults and consideration must be given to the stages of development and how these stages impact disease presentation and management. The final stage will be the transition from pediatric care to that of adult oriented care and special consideration must be given to make this a successful process. This review highlights special considerations in the management of the child with IBD.

Effect of calcium and vitamin D supplementation on bone mineral density in children with inflammatory bowel disease

OBJECTIVES

The purpose of this study was to evaluate the effect of calcium and vitamin D2 supplementation on bone mineral density (BMD) in children with inflammatory bowel disease (IBD).

PATIENTS AND METHODS

This was an open-label, prospective study conducted over a 12-month period. Seventy-two patients were divided into 2 groups based on lumbar spine areal BMD (L2-4 aBMD). Patients with an L2-4 aBMD z score of -1 or higher were assigned to the control group (n = 33; mean age, 11.0 +/- 3.5 years; 20 boys). Patients with an L2-4 aBMD of less than -1 (n = 39; mean age 11.8 +/- 2.5 years; 25 boys) were allocated to the intervention group and received 1000 mg of supplemental elemental calcium daily for 12 months (n = 19) or supplemental calcium for 12 months and 50,000 IU of vitamin D2 monthly for 6 months (n = 20).

RESULTS

The 2 groups differed in L2-4 aBMD z scores (intervention, -1.9 +/- 0.6; control, -0.2 +/- 0.6; P < 0.001) and volumetric L2-4 BMD (vBMD; intervention, 0.29 +/- 0.04; control, 0.33 +/- 0.06; P < 0.001). After 1 year of therapy, the control and intervention groups had similar changes in height z scores, L2-4 aBMD, L2-4 vBMD (z score change, L2-4 aBMD: control 0.2 +/- 0.6 [n = 21], intervention 0.4 +/- 0.6; P = 0.4 [n = 26]; z score change, L2-4 vBMD: control 0.1 +/- 0.4, intervention 0.2 +/- 0.6; P = 0.74). The changes in these parameters were similar between patients who had received calcium only or calcium plus vitamin D.

CONCLUSIONS

These results suggest that, in children with IBD, supplementation of calcium and vitamin D does not accelerate accrual in L2-4 BMD.

The prevalence of long bone fractures in pediatric inflammatory bowel disease

INTRODUCTION

The association of inflammatory bowel disease (IBD) with decreased bone mineral density is well recognized. In the adult population, up to 50% of IBD patients are reported to have osteopenia, correlating with an increase in the incidence of fractures as compared with controls. The aim of this study was to determine the prevalence of fractures in a pediatric population with IBD as compared with healthy sibling controls (SC).

PATIENTS AND METHODS

The families of 209 patients with IBD were sent a questionnaire asking them to compare their children with IBD to a healthy sibling (non-IBD).

RESULTS

Surveys were returned by 132 of the 209 families (63%). The sample characteristics of this sample closely resembled the overall clinic population for age (mean 14.3 vs 14.7 years), gender (53% vs 59% male) and diagnosis (58.1 vs 57.8 Crohn disease). Completed surveys described 263 children. Of the 132 with IBD 73 (55%) had Crohn disease, 52 (39%) had ulcerative colitis and 7 (6%) had indeterminate colitis. There were 76/132 males (age range, 4-18 years) with IBD and 64/131 males (age range, 1-26 years) in the sibling controls. Mean ages of the IBD sample 14.3 +/-.3 was compared with 13.9 +/- in SC. Of the total group, 73/263 (28%) reported ever having a fracture, 44 (60%) were siblings (SC), and 29 (40%) had IBD. Of the 29 children with IBD, 17 (59%) reported having a fracture after diagnosis including 2 who had fractures both before and after diagnosis. The total number of fractures reported was 96 (55 SC:41 IBD).

CONCLUSION

In this survey, we found no statistically significant difference in the prevalence of fracture in IBD patients compared with their normal siblings.

Metabolic Bone Disease in Children

Metabolic bone disease in children includes many hereditary and acquired conditions of diverse etiology that lead to disturbed metabolism of the bone tissue. Some of these processes primarily affect bone; others are secondary to nutritional deficiencies, a variety of chronic disorders, and/or treatment with some drugs. Some of these disorders are rare, but some present public health concerns (for instance, rickets) that have been well known for many years but still persist. The most important clinical consequences of bone metabolic diseases in the pediatric population include reduced linear growth, bone deformations, and non-traumatic fractures leading to bone pain, deterioration of motor development and disability. In this article, we analyze primary and secondary osteoporosis, rickets, osteomalacia (nutritional and hereditary vitamin D-dependent, hypophosphatemic and that due to renal tubular abnormalities), renal osteodystrophy, sclerosing bony disorders, and some genetic bone diseases (hypophosphatasia, fibrous dysplasia, skeletal dysplasia, juvenile Paget disease, familial expansile osteolysis, and osteoporosis pseudoglioma syndrome). Early identification and treatment of potential risk factors is essential for skeletal health in adulthood. In most conditions it is necessary to ensure an appropriate diet, with calcium and vitamin D, and an adequate amount of physical activity as a means of prevention. In secondary bone diseases, treatment of the primary disorder is crucial. Most genetic disorders await prospective gene therapies, while bone marrow transplantation has been attempted in other disorders. At present, affected patients are treated symptomatically, frequently by interdisciplinary teams. The role of exercise and pharmacologic therapy with calcium, vitamin D, phosphate, bisphosphonates, calcitonin, sex hormones, growth hormone, and thiazides is discussed. The perspectives on future therapy with insulin-like growth factor-1, new analogs of vitamin D, strontium, osteoprotegerin, and calcimimetics are presented.