Rapid improvement of bone metabolism after infliximab treatment in Crohn's disease

Navigating the Intersection: Sarcopenia and Sarcopenic Obesity in Inflammatory Bowel Disease

Inflammatory bowel diseases (IBDs) are intricate systemic conditions that can extend beyond the gastrointestinal tract through both direct and indirect mechanisms. Sarcopenia, characterized by a reduction in muscle mass and strength, often emerges as a consequence of the clinical course of IBDs. Indeed, sarcopenia exhibits a high prevalence in Crohn's disease (52%) and ulcerative colitis (37%). While computed tomography and magnetic resonance imaging remain gold-standard methods for assessing muscle mass, ultrasound is gaining traction as a reliable, cost-effective, and widely available diagnostic method. Muscle strength serves as a key indicator of muscle function, with grip strength test emerging nowadays as the most reliable assessment method. In IBDs, sarcopenia may arise from factors such as inflammation, malnutrition, and gut dysbiosis, leading to the formulation of the 'gut-muscle axis' hypothesis. This condition determines an increased need for surgery with poorer post-surgical outcomes and a reduced response to biological treatments. Sarcopenia and its consequences lead to reduced quality of life (QoL), in addition to the already impaired QoL. Of emerging concern is sarcopenic obesity in IBDs, a challenging condition whose pathogenesis and management are still poorly understood. Resistance exercise and nutritional interventions, particularly those aimed at augmenting protein intake, have demonstrated efficacy in addressing sarcopenia in IBDs. Furthermore, anti-TNF biological therapies showed interesting outcomes in managing this condition. This review seeks to furnish a comprehensive overview of sarcopenia in IBDs, elucidating diagnostic methodologies, pathophysiological mechanisms, and clinical implications and management. Attention will also be paid to sarcopenic obesity, exploring the pathophysiology and possible treatment modalities of this condition.

Bone Fragility in Gastrointestinal Disorders

Osteoporosis is a common systemic disease of the skeleton, characterized by compromised bone mass and strength, consequently leading to an increased risk of fragility fractures. In women, the disease mainly occurs due to the menopausal fall in estrogen levels, leading to an imbalance between bone resorption and bone formation and, consequently, to bone loss and bone fragility. Moreover, osteoporosis may affect men and may occur as a sequela to different diseases or even to their treatments. Despite their wide prevalence in the general population, the skeletal implications of many gastrointestinal diseases have been poorly investigated and their potential contribution to bone fragility is often underestimated in clinical practice. However, proper functioning of the gastrointestinal system appears essential for the skeleton, allowing correct absorption of calcium, vitamins, or other nutrients relevant to bone, preserving the gastrointestinal barrier function, and maintaining an optimal endocrine-metabolic balance, so that it is very likely that most chronic diseases of the gastrointestinal tract, and even gastrointestinal dysbiosis, may have profound implications for bone health. In this manuscript, we provide an updated and critical revision of the role of major gastrointestinal disorders in the pathogenesis of osteoporosis and fragility fractures.

The Effect of Nutritional Therapy on Bone Mineral Density and Bone Metabolism in Pediatric Crohn Disease

OBJECTIVES

Both the inflammatory burden of Crohn disease (CD) and corticosteroids have a negative effect on bone density. Exclusive enteral nutrition (EEN) avoids corticosteroids and promotes endoscopic healing. We aimed to explore the effect of nutritional therapy on bone health in pediatric CD.

METHODS

This was a planned sub-study of a clinical trial enrolling children with new-onset mild-moderate CD. Children were randomized to either 6 weeks EEN followed by 6 weeks 25% partial enteral nutrition (PEN) or 6 weeks of 50% PEN with a CD exclusion diet followed by 6 weeks of 25% PEN with exclusion diet. Bone formation and resorption were measured at baseline, week 12 and week 24 by serum C-Propeptide of Type I Procollagen (CICP) and type I Collagen N-Telopeptide (NTX), respectively. Bone mineral density (BMD) was measured by dual energy X-ray absorptiometry (DXA) scan at baseline and week 24.

RESULTS

Median CICP improved from 130 ng/mL (106-189) at baseline to 223 (143-258) at week 12 and 193 (143-252) at week 24 (P = 0.016 for both, n = 29 children). Median NTX remained unchanged (P = 0.45 and P = 0.45). Thirty-six children had DXA scans performed at diagnosis; 81% and 33% had z scores of <-1 and <-2, respectively. DXA z scores did not improve from baseline (adjusted total body less head [TBLH] BMD -1.62 ± 0.87) to week 24 (-1.76 ± 0.75; P = 0.30, n = 21 with both scans).

CONCLUSIONS

Low bone density is common in new-onset mild-moderate pediatric CD. CICP, a sensitive marker of bone formation, improved following dietary intervention but this was not associated with improved BMD.

Serum N-terminal telopeptide of type I collagen as a biomarker for predicting bone density loss in patients with Crohn disease

Background

The serum N-terminal telopeptide of type I collagen (NTx) is significantly higher in patients with Crohn disease (CD) than in healthy individuals and patients with ulcerative colitis. This study aimed to investigate whether an elevated serum NTx level is a risk predictor of osteoporosis in patients with CD.

Methods

Based on whether the femoral Z-score decreased over a 2-year period, 41 CD patients were divided into the ΔZ-score <0 group (Z-score decreased) and the ΔZ-score ≥0 group (Z-score did not decrease). The risk predictors of a femoral Z-score decrease were examined. Furthermore, we investigated the correlations between the ΔZ-score (which represents the change in the Z-score over a 2-year period) and the mean levels of biomarkers, including the Crohn Disease Activity Index (CDAI), serum albumin, C-reactive protein, and bone metabolism markers (including NTx) measured initially (i.e., in our previous study) and 2 years later (present study). The relationships between anti-tumor necrosis factor α (anti-TNF-α) therapy and serum NTx levels were also examined.

Results

Although there was no correlation between the mean CDAI and the ΔZ-score, the mean serum NTx and albumin levels were significantly correlated with the ΔZ-score (P<0.01 and P = 0.02, respectively). Furthermore, the femoral Z-score tended to be lower in the anti-TNF-α administration group than in the non-administration group.

Conclusions

These observations indicated that an elevated serum NTx could be a useful marker for predicting a decrease in the femoral bone mineral density in CD patients. Anti-TNF-α therapy maintained an elevated serum NTx level, suggesting that treatment with anti-TNF-α may help control increased bone resorption in CD patients.

Bone Health in Patients With Inflammatory Bowel Diseases

Inflammatory bowel disease (IBD) is a chronic inflammatory medical condition with relapses and remission. Metabolic bone disease, including osteoporosis, is associated with IBD and imparts a significant morbidity if pathologic fractures were to occur. There has been a significant amount of research that evaluated the pathophysiology and associations between IBD and osteoporosis. Although corticosteroids contribute to the risk of low bone mineral density, osteoporosis and fractures, older age, female gender, smoking, and family history of fracture have been shown to contribute. Additionally, intestinal inflammation affects bone resorption and formation through proinflammatory cytokines such as tumor necrosis factor-a, interleukin-1, and interleukin-6 further accelerating bone loss. Little information is available on standardizing screening or treatment. It is important to recognize the risk factors that are associated with IBD and osteoporosis to identify the patient population at risk and initiate treatment/prevention strategies early. Treatment can include calcium, vitamin D, or bisphosphonates. Some studies showed benefit of treating the underlying IBD to improve bone mineral density.

Azathioprine Has a Deleterious Effect on the Bone Health of Mice with DSS-Induced Inflammatory Bowel Disease

Patients with inflammatory bowel disease (IBD) often present poor bone health and are 40% more at risk of bone fracture. Studies have implicated autophagy in IBD pathology and drugs used to treat IBD stimulate autophagy in varying degrees, however, their effect on the skeleton is currently unknown. Here, we have utilised the dextran sulphate sodium (DSS) model of colitis in mice to examine the effects of the thiopurine drug azathioprine on the skeleton. Ten-week-old male mice (n = 6/group) received 3.0% DSS in their drinking water for four days, followed by a 14-day recovery period. Mice were treated with 10 mg/kg/day azathioprine or vehicle control. Histopathological analysis of the colon from DSS mice revealed significant increases in scores for inflammation severity, extent, and crypt damage (p < 0.05). Azathioprine provided partial protection to the colon, as reflected by a lack of significant difference in crypt damage and tissue regeneration with DSS treatment. MicroCT of vehicle-treated DSS mice revealed azathioprine treatment had a significant detrimental effect on the trabecular bone microarchitecture, independent of DSS treatment. Specifically, significant decreases were observed in bone volume/tissue volume (p < 0.01), and trabecular number (p < 0.05), with a concurrent significant increase in trabecular pattern factor (p < 0.01). Immunohistochemical labelling for LC3 revealed azathioprine to induce autophagy in the bone marrow. Together these data suggest that azathioprine treatment may have a deleterious effect on IBD patients who may already be at increased risk of osteoporotic bone fractures and thus will inform on future treatment strategies for patient stratification.

Bone alterations in inflammatory bowel diseases

Inflammatory bowel diseases (IBDs) are characterized by a multifactorial partially unknown etiology that involves genetic, immunological and environmental factors. Up to 50% of IBD patients experience at least one extraintestinal manifestation; among them is the involvement of bone density which is referred to as metabolic bone disease (MBD), including osteopenia and osteoporosis. Bone alterations in IBDs population appear to have a multifactorial etiology: Decreased physical activity, inflammation-related bone resorption, multiple intestinal resections, dietary malabsorption of minerals and vitamin D deficiency, genetic factors, gut-bone immune signaling interaction, steroid treatment, microbiota and pathogenic micro-organisms interaction, and dietary malabsorption of minerals, that, all together or individually, may contribute to the alteration of bone mineral density. This review aims to summarize the prevalence and pathophysiology of metabolic bone alterations in IBD subjects outlining the main risk factors of bone fragility. We also want to underline the role of the screening and prophylaxis of bone alterations in Crohn’s disease and ulcerative colitis patients and the importance of treating appropriately MBD.

Management of Paediatric Ulcerative Colitis, Part 1: Ambulatory Care-An Evidence-based Guideline From European Crohn's and Colitis Organization and European Society of Paediatric Gastroenterology, Hepatology and Nutrition

BACKGROUND

The contemporary management of ambulatory ulcerative colitis (UC) continues to be challenging with ∼20% of children needing a colectomy within childhood years. We thus aimed to standardize daily treatment of pediatric UC and inflammatory bowel diseases (IBD)-unclassified through detailed recommendations and practice points.

METHODS

These guidelines are a joint effort of the European Crohn's and Colitis Organization (ECCO) and the Paediatric IBD Porto group of European Society of Paediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN). An extensive literature search with subsequent evidence appraisal using robust methodology was performed before 2 face-to-face meetings. All 40 included recommendations and 86 practice points were endorsed by 43 experts in Paediatric IBD with at least an 88% consensus rate.

RESULTS

These guidelines discuss how to optimize the use of mesalamine (including topical), systemic and locally active steroids, thiopurines and, for more severe disease, biologics. The use of other emerging therapies and the role of surgery are also covered. Algorithms are provided to aid therapeutic decision-making based on clinical assessment and the Paediatric UC Activity Index (PUCAI). Advice on contemporary therapeutic targets incorporating the use of calprotectin and the role of therapeutic drug monitoring are presented, as well as other management considerations around pouchitis, extraintestinal manifestations, nutrition, growth, psychology, and transition. A brief section on disease classification using the PIBD-classes criteria and IBD-unclassified is also part of these guidelines.

CONCLUSIONS

These guidelines provide a guide to clinicians managing children with UC and IBD-unclassified management to provide modern management strategies while maintaining vigilance around appropriate outcomes and safety issues.

Anti-tumor necrosis factor agents in Crohn's disease and ulcerative colitis: Beyond luminal disease

Anti-tumor necrosis factor agents (anti-TNF) drugs are commonly used in patients with inflammatory bowel disease (IBD) and have proven effective in both induction and maintenance therapy in luminal Crohn's disease and ulcerative colitis. Their efficacy has also been proven in fistulising perianal Crohn's disease. However, the evidence in other scenarios, such as stricturing, penetrating and non-fistulising perianal Crohn's disease, extraintestinal IBD manifestations and ileoanal reservoir complications, is not as robust. The aim of this review was to perform an analysis of the available literature and to determine the role of anti-TNF drugs in common clinical practice in patients affected by these complications.

Exercise and Inflammatory Bowel Disease: Insights into Etiopathogenesis and Modification of Clinical Course

There is sparse information regarding exercise and inflammatory bowel disease (IBD). Furthermore, the importance of regular exercise in the optimal management of IBD has not received attention in guidelines and is often overlooked by practitioners. This article summarizes evidence regarding health benefits of exercise, guidelines regarding exercise in the general population and chronic inflammatory disorder populations, limitations regarding exercise capacity in patients with IBD, the association of lack of exercise with IBD pathogenesis, the role of exercise in beneficially modulating IBD clinical course, and extraintestinal benefits of exercise in patients with IBD.

Inflammatory diseases and bone fragility

Systemic osteoporosis and increased fracture rates have been described in chronic inflammatory diseases such as rheumatoid arthritis, spondyloarthritis, systemic lupus erythematosus, inflammatory bowel diseases, and chronic obstructive pulmonary disease. Most of these patients receive glucocorticoids, which have their own deleterious effects on bone. However, the other main determinant of bone fragility is the inflammation itself, as shown by the interactions between the inflammatory mediators, the actors of the immune system, and the bone remodelling. The inflammatory disease activity is thus on top of the other well-known osteoporotic risk factors in these patients. Optimal control of inflammation is part of the prevention of osteoporosis, and potent anti-inflammatory drugs have positive effects on surrogate markers of bone fragility. More data are needed to assess the anti-fracture efficacy of a tight control of inflammation in patients with a chronic inflammatory disorder. This review aimed at presenting different clinical aspects of inflammatory diseases which illustrate the relationships between inflammation and bone fragility.

Systematic Review of Tumor Necrosis Factor Antagonists in Extraintestinal Manifestations in Inflammatory Bowel Disease

BACKGROUND & AIMS

This systematic review investigated the efficacy and the effectiveness of biologic drugs in extraintestinal manifestations (EIMs) in inflammatory bowel disease (IBD).

METHODS

Literature search was conducted in PubMed, Embase, and Cochrane until October 2015. Main inclusion criteria were adults with IBD, use of a biologic drug, evolution of EIMs, interventional study, or non-interventional study.

RESULTS

Nine interventional studies (2 randomized controlled trials [N = 797], 7 open label trials [N = 1143], and 13 non-interventional studies [N = 914]) were included. Tumor necrosis factor (TNF) antagonists achieved complete response for pyoderma gangrenosum in 21%-25% of patients in interventional studies and in 92%-100% patients in non-interventional studies, with similar results for other cutaneous manifestations such as erythema nodosum or stomatitis. Adalimumab significantly reduced the prevalence of anemia vs placebo after 56 weeks in 1 randomized controlled trial. In 2 non-interventional studies, anti-TNF therapy improved anemia in the short-term (67%) and in the long-term (34%). Complete response after anti-TNF treatment was reported in interventional studies, including arthralgia (reduction in prevalence from 47.1% to 26.8% in the mid-term in 1 open label trial) and arthritis (reduction in prevalence from 8.7% to 2.1% and from 58% to 12.5% in 2 open label trials). Anti-TNFs were beneficial for a majority of patients with ocular manifestations. Infliximab was associated with improved outcomes in bone formation and bone mineral density.

CONCLUSIONS

Anti-TNFs appear to be effective alternatives for certain EIMs associated with IBD including musculoskeletal, cutaneous, and ocular manifestations, and some beneficial effect may be obtained in metabolic bone disease and on hematologic or vascular EIMs.

A 1-year prospective study of the effect of infliximab on bone metabolism in inflammatory bowel disease patients

OBJECTIVES

Infliximab (IFX) treatment has shown potentially beneficial effects on bone metabolism in inflammatory bowel disease (IBD) patients. We aimed to prospectively evaluate the impact of IFX treatment on bone metabolism in antitumour necrosis factor (TNF)-α-naive IBD patients using established bone metabolism markers and an in-vitro osteoblast model.

MATERIALS AND METHODS

A total of 37 anti-TNFα-naive IBD patients and 20 healthy controls were included. All measurements were performed at baseline and repeated in IBD patients following IFX therapy. Bone mineral density was measured by dual-energy X-ray absorptiometry. Parathyroid hormone, vitamin D, osteoprotegerin, soluble receptor activator of nuclear factor B ligand and proinflammatory and anti-inflammatory cytokines were measured. Bone formation was measured using osteocalcin (OC) and procollagen type 1N propeptide, and bone resorption was measured using serum type 1 collage c-telopeptide. The effect of control and IBD patient sera on human osteoblast viability and differentiation was analysed.

RESULTS

OC level was higher in controls than IBD patients (P=0.018). After IFX, OC and procollagen type 1N propeptide increased significantly (P=0.002 and 0.011) and (P<0.001 and P=0.016) at weeks 6 and 30 after treatment, respectively. There was a nonsignificant decrease in serum type 1 collage c-telopeptide. After IFX therapy, proinflammatory cytokines TNF-α, interleukin-6 and interleukin-13 decreased significantly (P=0.016, week 54; P=0.005, week 6 and P=0.025, week 6), respectively. Sera from IBD patients before IFX showed increased osteoblast viability compared with the controls (P=0.003 to P<0.005), but induced reduced osteoblast differentiation. After IFX, viability reduced to control levels, but osteoblast differentiation increased (P=0.041).

CONCLUSION

IFX treatment induced beneficial effects on bone metabolism. Osteoblast culture results suggest that IBD patients may have increased osteoblast viability, but reduced differentiation, which has implications for bone strength.

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.

An Increased Serum N-Terminal Telopeptide of Type I Collagen, a Biochemical Marker of Increased Bone Resorption, Is Associated with Infliximab Therapy in Patients with Crohn's Disease

BACKGROUND

Osteopenia and osteoporosis are considered to be extra-intestinal manifestations of inflammatory bowel disease (IBD). Anti-tumor necrosis factor (TNF)-α biologics have been introduced as novel medications for an active IBD. However, it is still not well documented whether anti-TNF-α affects the frequency of bone loss or abnormality of bone mineral markers among patients with IBD.

AIMS

This study was to investigate the biochemical basis of low bone mineral density (BMD) and increased turnover in IBD during infliximab (IFX) therapy.

METHODS

Forty patients with Crohn's disease (CD), 80 patients with ulcerative colitis (UC), and 65 age- and gender-matched controls were included. BMD was measured with dual-energy X-ray absorptiometry, and vitamins K and D were measured as serum undercarboxylated osteocalcin (ucOC) and 1,25-(OH)2D, respectively. Bone formation and resorption were based on measuring bone-specific alkaline phosphatase (BAP) and serum N-terminal telopeptide of type I collagen (NTx), respectively.

RESULTS

Significantly lower BMD was found in patients with UC and CD as compared to controls (P < 0.05). BAP, 1,25-(OH)2D, ucOC, and NTx were significantly higher in CD patients, but not in UC patients as compared to controls (P < 0.05). Further, serum NTx level was significantly higher in CD patients who were receiving IFX as compared to CD patients who were not receiving IFX (P < 0.01).

CONCLUSIONS

A lower BMD and higher bone metabolism markers were found in CD patients as compared to controls or UC patients. A significant increased serum level of NTx, a biochemical marker of increased bone resorption, was observed in CD patients during IFX therapy.

Risk factors for osteoporosis in inflammatory bowel disease patients

Inflammatory bowel disease (IBD) patients exhibit higher risk for bone loss than the general population. The chronic inflammation causes a reduction in bone mineral density (BMD), which leads to osteopenia and osteoporosis. This article reviewed each risk factor for osteoporosis in IBD patients. Inflammation is one of the factors that contribute to osteoporosis in IBD patients, and the main system that is involved in bone loss is likely RANK/RANKL/osteoprotegerin. Smoking is a risk factor for bone loss and fractures, and many mechanisms have been proposed to explain this loss. Body composition also interferes in bone metabolism and increasing muscle mass may positively affect BMD. IBD patients frequently use corticosteroids, which stimulates osteoclastogenesis. IBD patients are also associated with vitamin D deficiency, which contributes to bone loss. However, infliximab therapy is associated with improvements in bone metabolism, but it is not clear whether the effects are because of inflammation improvement or infliximab use. Ulcerative colitis patients with proctocolectomy and ileal pouches and Crohn’s disease patients with ostomy are also at risk for bone loss, and these patients should be closely monitored.

Adalimumab Therapy Has a Beneficial Effect on Bone Metabolism in Patients with Crohn's Disease

BACKGROUND

Infliximab has been shown to have beneficial effects on bone metabolism in patients with Crohn's disease (CD) although as yet the exact mechanisms have not been fully elucidated.

AIM

To evaluate the impact of adalimumab therapy on bone metabolism using a combined in vivo and in vitro model.

METHODS

Parathyroid hormone, vitamin D, bone formation markers, bone resorption marker, pro-inflammatory cytokines, anti-inflammatory cytokines, osteoprotegerin, and sRANKL were measured in control patients and pre- and post-treatment with adalimumab in CD patients. The effect of control patients' and pre- and post-treatment CD patients' sera on human osteoblasts (hFOB 1.19) in vitro cell viability and differentiation was also analyzed.

RESULTS

There was a significant increase in bone formation markers osteocalcin (P < 0.05) and procollagen type 1 N-terminal propeptide (P < 0.01) at 1 and 3 months post-treatment. Moreover, there was a sustained but not significant fall in serum CTx, a bone resorption marker. No significant change was seen over time with other parameters measured. Serum from CD patients pre-treated with adalimumab showed increased osteoblast viability compared with that of post-treated patients at 6 months (P = 0.002) and controls. However, post-adalimumab treatment sera at 6 months appeared to increase osteoblast differentiation (P = 0.001), which is likely to be important in new bone formation.

CONCLUSIONS

This first study evaluating the role of adalimumab as a possible bone protector in Crohn's disease patients has shown that similar to infliximab, adalimumab has complex and potentially beneficial effects on bone metabolism.

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.

Bone Loss Triggered by the Cytokine Network in Inflammatory Autoimmune Diseases

Bone remodeling is a lifelong process in vertebrates that relies on the correct balance between bone resorption by osteoclasts and bone formation by osteoblasts. Bone loss and fracture risk are implicated in inflammatory autoimmune diseases such as rheumatoid arthritis, ankylosing spondylitis, inflammatory bowel disease, and systemic lupus erythematosus. The network of inflammatory cytokines produced during chronic inflammation induces an uncoupling of bone formation and resorption, resulting in significant bone loss in patients with inflammatory autoimmune diseases. Here, we review and discuss the involvement of the inflammatory cytokine network in the pathophysiological aspects and the therapeutic advances in inflammatory autoimmune diseases.

Infliximab reverses inflammatory muscle wasting (sarcopenia) in Crohn's disease

BACKGROUND

Muscle wasting or sarcopenia arising from chronic inflammation is found in 60% of patients with Crohn's disease. Transcriptional protein NF-κB reduces muscle formation through MyoD transcription and increases muscle breakdown by proteolysis.

AIM

As TNF is a potent activator of NF-κB, and anti-TNF agent infliximab (IFX) prevents NF-κB activation, to determine whether or not Crohn's patients treated with IFX gain muscle volume and strength.

METHODS

We performed a prospective, repeated-measures cohort study in adult Crohn's disease patients with an acute disease flare. Patients were instructed not to vary diet or activity. Concomitant medications were kept stable. At week 1 (pre-treatment), week 16 (post-IFX induction) and week 25 (post-first IFX maintenance dose), we assessed (i) MRI volume of quadriceps femoris at anatomical mid-thigh; (ii) maximal concentric quadriceps contractions strength at three specific speeds of contraction; (iii) physical activity by validated instrument (IPAQ); (iv) Three-day food record of intake and composition (food-weighing method); (v) Serum levels of IL6.

RESULTS

Nineteen patients (58% female; mean age 33.2 ± 10.7 years) were recruited. IFX increased muscle volume in both legs from baseline (right, 1505 cm(3) ) to week 25 (right, 1569 cm(3) ; P = 0.010). IFX also increased muscle strength in both legs from baseline (right 30°/s, 184.8 Nm) to week 25 (right 30°/s, 213.6 Nm; P = 0.002). Muscle volume gain correlated with male gender (P = 0.003). Significant gains in muscle volume and strength were unrelated to prednisolone use. Serum IL6 levels decreased by week 25 (P = 0.037).

CONCLUSION

The anti-TNF agent infliximab reverses inflammatory sarcopenia in patients with Crohn's disease.

Consensus guidelines of ECCO/ESPGHAN on the medical management of pediatric Crohn's disease

Children and adolescents with Crohn's disease (CD) present often with a more complicated disease course compared to adult patients. In addition, the potential impact of CD on growth, pubertal and emotional development of patients underlines the need for a specific management strategy of pediatric-onset CD. To develop the first evidenced based and consensus driven guidelines for pediatric-onset CD an expert panel of 33 IBD specialists was formed after an open call within the European Crohn's and Colitis Organisation and the European Society of Pediatric Gastroenterolog, Hepatology and Nutrition. The aim was to base on a thorough review of existing evidence a state of the art guidance on the medical treatment and long term management of children and adolescents with CD, with individualized treatment algorithms based on a benefit-risk analysis according to different clinical scenarios. In children and adolescents who did not have finished their growth, exclusive enteral nutrition (EEN) is the induction therapy of first choice due to its excellent safety profile, preferable over corticosteroids, which are equipotential to induce remission. The majority of patients with pediatric-onset CD require immunomodulator based maintenance therapy. The experts discuss several factors potentially predictive for poor disease outcome (such as severe perianal fistulizing disease, severe stricturing/penetrating disease, severe growth retardation, panenteric disease, persistent severe disease despite adequate induction therapy), which may incite to an anti-TNF-based top down approach. These guidelines are intended to give practical (whenever possible evidence-based) answers to (pediatric) gastroenterologists who take care of children and adolescents with CD; they are not meant to be a rule or legal standard, since many different clinical scenario exist requiring treatment strategies not covered by or different from these guidelines.

Influence of exclusive enteral nutrition therapy on bone density and geometry in newly diagnosed pediatric Crohn's disease patients

BACKGROUND AND AIMS

Exclusive enteral nutrition (EEN) induces remission in patients with Crohn's disease (CD). We investigated the short-term impact of EEN on bone quality and muscle mass in children with CD.

METHODS

Ten newly diagnosed CD patients (7 male, 10.6-17.7 years of age) were assessed by peripheral quantitative computed tomography (pQCT) at the forearm before starting an 8-weeks treatment with EEN, and after 12 and 52 weeks. No steroids or biologicals were applied. Trabecular and cortical bone mineral density, total bone, and muscle cross-sectional area (CSA) were measured by pQCT and expressed as age- and sex-specific z-scores; size-dependent CSAs were corrected for low height for age. Wilcoxon rank sum test was applied.

RESULTS

Remission at week 12 was achieved in 8 patients; 2 still had mild disease. Initially low trabecular density z-scores improved (+0.3; p = 0.006) at week 12; simultaneously, the increased cortical density z-scores normalized (-0.4; p = 0.027). The low z-score for muscle CSA corrected for height (median -2.5, range -3.49 to -0.97) increased within 12 weeks (+1.0; p = 0.002) with no further improvement thereafter.

CONCLUSIONS

The results indicate disturbed bone remodeling and severely impaired muscle mass in newly diagnosed CD children. Bone metabolism and muscle mass improved within 3 months after starting EEN with no further normalization thereafter.

Risk factors for osteoporosis in Crohn's disease: infliximab, corticosteroids, body mass index, and age of onset

BACKGROUND

We analyzed the characteristics associated with increased risk of osteoporosis in patients with Crohn's disease in Malta.

METHOD

Eighty-three patients with histologically and endoscopically confirmed Crohn's disease underwent a DEXA bone density scan and their phenotypic characteristics were analyzed.

RESULTS

There was a significant association between body mass index and bone mineral density (P = 0.004) and a significant difference in the T scores of patients according to age at diagnosis (Montreal Classification: P = 0.0006) with patients diagnosed <17 years (n = 13) having lower T scores than those diagnosed at older age groups (n = 70). There was a significant difference between the T scores of patients on infliximab (n = 33) and those not on biological therapy (n = 50, P = 0.0058). Patients with high cumulative corticosteroid doses (>10 mg/d for >3 mo, n = 18) had lower bone mineral densities than patients who received smaller corticosteroid doses (P = 0.013). There was however no significant difference in the T scores of patients according to disease location (P = 0.18), disease type (P = 0.64), gender (P = 0.30), and history of ileal resection (P = 0.68). There was also no significant correlation between disease duration and T scores (hip) (P = 0.61).

CONCLUSIONS

Low body mass index, early disease onset, high corticosteroid doses and, anti-tumor necrosis factor α therapy are associated with increased risk of osteoporosis. Lower T scores in patients on infliximab occur as patients receiving this therapy have more severe inflammation, which is associated with elevated osteoclastogenic factors, rather than as a side-effect of the anti-tumor necrosis factor-α therapy.

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.

[Clinical practice guidelines for evaluation and treatment of osteoporosis associated to endocrine and nutritional conditions. Bone Metabolism Working Group of the Spanish Society of Endocrinology]

OBJECTIVE

To provide practical recommendations for evaluation and treatment of osteoporosis associated to endocrine diseases and nutritional conditions.

PARTICIPANTS

Members of the Bone Metabolism Working Group of the Spanish Society of Endocrinology, a methodologist, and a documentalist.

METHODS

Recommendations were formulated according to the GRADE system (Grading of Recommendations, Assessment, Development, and Evaluation) to describe both the strength of recommendations and the quality of evidence. A systematic search was made in MEDLINE (Pubmed), using the following terms associated to the name of each condition: AND "osteoporosis", "fractures", "bone mineral density", and "treatment". Papers in English with publication date before 18 October 2011 were included. Current evidence for each disease was reviewed by two group members, and doubts related to the review process or development of recommendations were resolved by the methodologist. Finally, recommendations were discussed in a meeting of the Working Group.

CONCLUSIONS

The document provides evidence-based practical recommendations for evaluation and management of endocrine and nutritional diseases associated to low bone mass or an increased risk of fracture. For each disease, the associated risk of low bone mass and fragility fractures is given, recommendations for bone mass assessment are provided, and treatment options that have shown to be effective for increasing bone mass and/or to decreasing fragility fractures are listed.

Skeletal health of children and adolescents with inflammatory bowel disease

Current evidence points to suboptimal bone health in children and adolescents with inflammatory bowel disease (IBD) when compared with their healthy peers. This compromise is evident from diagnosis. The clinical consequences and long-term outcome of this finding are still unknown. The mechanism of suboptimal bone health in children and adolescents with IBD lays mainly in reduced bone formation, but also reduced bone resorption, processes necessary for bone growth. Factors contributing to this derangement are inflammation, delayed growth and puberty, lean mass deficits, and use of glucocorticoids. We recognize that evidence is sparse on the topic of bone health in children and adolescents with IBD. In this clinical guideline, based on current evidence, we provide recommendations on screening and monitoring bone health in children and adolescents with IBD, including modalities to achieve this and their limitations; monitoring of parameters of growth, pubertal development, and reasons for concern; evaluation of vitamin D status and vitamin D and calcium intake; exercise; and nutritional support. We also report on the current evidence of the effect of biologics on bone health in children and adolescents with IBD, as well as the role of bone active medications such as bisphosphonates. Finally, we summarize the existing numerous gaps in knowledge and potential subjects for future research endeavors.

Crohn's disease in a child: unusual presentation with severe osteoporosis

Crohn's disease is a chronic inflammatory bowel disease characterized by transmural, granulomatous inflammation. In paediatric-onset Crohn's disease, the most frequent clinical features are abdominal pain, diarrhoea, fatigue and weight loss. Delayed puberty, growth retardation and osteoporosis might, however, be the predominant signs of the disease. This paper reports the case of a 13-year-old girl with Crohn's disease diagnosed at the age of 11 years, with classic gastrointestinal symptoms in the previous few months, but with severe osteoporosis at onset. The child has been on infliximab therapy for 1 year, with complete control of the disease. Therapy with infliximab appears to influence bone metabolism, bone formation and resorption, and that improvement seems to be independent of the clinical response to the drug. Infliximab has recently been approved for paediatric use, which has been a great improvement for a group of patients lacking therapeutic options.

Special considerations for women with IBD

Inflammatory bowel diseases (IBD), namely Crohn disease (CD) and ulcerative colitis (UC), are common in Western society. Because at least half of the patients suffering from these diseases are women, it is important that physicians are aware of their gender-specific needs. There are multiple important concerns for women with UC and CD including issues of body image and sexuality, menstruation, contraception, screening for cervical cancer, matters related to menopause and hormone replacement therapy, osteoporosis, and the overlap seen between IBS and IBD. In this article, we have addressed these important, non-pregnancy-related issues faced by women with IBD.

Review article: the effects of antitumour necrosis factor-α on bone metabolism in inflammatory bowel disease

BACKGROUND

Patients with inflammatory bowel disease (IBD) are at increased risk of osteoporosis. A number of studies have emerged in recent years indicating that tumour necrosis factor (TNF) blockade appears to have a beneficial effect on bone mineral density (BMD) in IBD patients.

AIMS

To provide a review of the available data regarding the effect of the currently licensed anti-TNF-α therapies on bone metabolism and BMD in IBD patients.

METHODS

A Medline search was performed using the search terms 'infliximab', 'bone metabolism', 'IBD', 'BMD', 'bone markers', 'adalimumab', 'bone disease', 'Crohn's disease' and 'ulcerative colitis'.

RESULTS

Infliximab has a beneficial effect on bone turnover markers in Crohn's disease (CD) patients in the short term. The longest study to date comprising 24 CD patients showed an overall improvement in two bone formation markers - b-alkaline phosphatase (P = 0.022) and osteocalcin (P = 0.008) at 4 months post-treatment. Moreover, the largest study to date comprising 71 CD patients showed significant improvement in sCTx, a bone resorption marker (P = 0.04) at week-8 post-treatment. There is little data looking at the effect of anti-TNF-α therapy on bone metabolism in ulcerative colitis. Moreover, the long-term effects of anti-TNF-α therapy on bone structure and fracture risk in IBD patients are currently not known. The effect of cessation of anti-TNF-α therapy on bone metabolism is also unknown.

CONCLUSION

Properly controlled long-term trials are needed to fully evaluate the impact of TNF blockade on bone mineral density.

Safety and efficacy of maintenance infliximab therapy for moderate-to-severe Crohn's disease in children: REACH open-label extension

OBJECTIVE

Assess long-term effects of maintenance infliximab therapy in children with moderately-to-severely active Crohn's disease.

RESEARCH DESIGN AND METHODS

One hundred twelve patients with a Pediatric Crohn's Disease Activity Index (PCDAI) score >30 received infliximab 5 mg/kg at weeks 0, 2, and 6 in the REACH study. Patients considered responders at week 10 were randomized to infliximab 5 mg/kg every 8 (q8w) or 12 (q12w) weeks. Patients who completed treatment through week 46, and who the investigator believed would benefit from continued treatment, could enter the open-label extension (OLE) and receive up to three additional years of infliximab. No hypothesis testing was performed.

CLINICAL TRIAL REGISTRATION

www.clinicaltrials.gov, identifier: NCT0020767.

RESULTS

Sixty children entered the OLE: 33, 12, and 15 patients were receiving infliximab 5 mg/kg q8w, 5 mg/kg q12w, and 10 mg/kg q8w, respectively, at extension entry. Patients receiving infliximab for up to 3 years during the OLE maintained clinical benefit, with approximately 80% of patients consistently having no to mild disease activity per the physician's global assessment and very good to fair health in the past 2 weeks per the patient and parent/guardian global assessments. Patients with ≥1-year delay in bone age at baseline trended toward improvement in height during the OLE. Respiratory system disorders, most commonly upper respiratory infections, were the most prevalent adverse events reported; six (10%) patients had serious infections.

CONCLUSIONS

Among children with moderately-to-severely active Crohn's disease who received infliximab for 46 weeks in REACH and then for up to 3 additional years in the REACH OLE, infliximab was effective in maintaining clinical benefit and was generally well-tolerated.

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.

Effect of exclusive enteral nutrition on bone turnover in children with Crohn's disease

BACKGROUND

Poor bone acquisition and increased fracture risk are significant complications associated with Crohn's disease (CD). The aim of this study was to determine the effects of 8 weeks of exclusive enteral nutrition (EEN) therapy upon markers of bone turnover in children with newly diagnosed CD.

METHODS

Twenty-three children with newly diagnosed CD and 20 controls (without CD) were enrolled. Children with CD were treated with 8 weeks of EEN. Inflammatory markers [C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), albumin, platelets], nutritional markers (height, weight), and bone markers [C-terminal telopeptides of Type-1 collagen (CTX) and bone specific alkaline phosphatase (BAP)] were measured prior to and following therapy.

RESULTS

At diagnosis, children with CD had elevated serum CTX (2.967 +/- 0.881 ng/ml) compared to controls (2.059 +/- 0.568 ng/ml; P = 0.0003). Following the period of EEN, CTX levels fell significantly (2.260 +/- 0.547 ng/ml; P = 0.002), while serum BAP levels (51.24 +/- 31.31 microg/L at diagnosis; control serum BAP = 66.80 +/- 23.23 microg/L; P = 0.07) increased significantly (64.82 +/- 30.51 microg/L; P = 0.02), with both normalizing to control levels.

CONCLUSIONS

As well as reducing inflammation, decreasing disease activity, and improving nutrition in children with newly diagnosed CD, EEN therapy also normalized serum markers of bone turnover, suggesting an improvement in bone health. Further investigations of short- and long-term effects of EEN on bone density and overall bone health are now required.

Osteoporosis in inflammatory bowel disease

Osteoporosis commonly afflicts patients with inflammatory bowel disease, and many factors link the 2 states together. A literature review was conducted about the pathophysiology of osteoporosis in relation to inflammatory bowel disease. Screening guidelines for osteoporosis in general as well as those directed at patients with inflammatory bowel disease are reviewed, as are currently available treatment options. The purpose of this article is to increase physician awareness about osteopenia and osteoporosis occurring in patients with inflammatory bowel disease and to provide basic, clinically relevant information about the pathophysiology and guidelines to help them treat these patients in a cost-effective manner.

Proinflammatory cytokines and receptor activator of nuclear factor kappaB-ligand/osteoprotegerin associated with bone deterioration in patients with Crohn's disease

OBJECTIVES

The high incidence of bone disease and the increasing evidence of Crohn's disease (CD) bone decline in corticosteroid users and nonusers suggest that bone metabolism is affected by inflammatory process. The aim of the study was to compare serum levels of proinflammatory cytokines, markers of bone turnover and regulatory molecules of osteoclast biogenesis, receptor activator of nuclear factor kappaB-ligand (RANKL) and osteoprotegerin (OPG), between naïve and long-standing CD patients.

METHODS

The study included 95 CD patients, 15 of them with newly diagnosed and previously untreated CD. The spine and hip bone mineral density was measured by dual-energy X-ray absorptiometry. Biochemical markers were determined by immunoassay.

RESULTS

Osteopenia was recorded at diagnosis in 53% of naïve patients and osteoporosis was found in 26% of long-standing CD patients. The newly diagnosed patients showed correlation between TNF-alpha and soluble RANKL (sRANKL) (r=0.5; P=0.04), and this positive relationship characterized the study population as a whole (r=0.3; P=0.003). Analysis of the OPG and sRANKL relationship showed absence of correlation in patients with healthy skeleton, whereas an inverse correlation was found in those with osteopenia (r=-0.31; P=0.033) and osteoporosis (r=-0.48; P=0.028). In naïve patients with reduced T score, the correlation between sRANKL and OPG was highly inverse (r=-0.8; P=0.02) and these patients were characterized by lower BMI, significantly higher level of proinflammatory cytokines, elevated C-reactive protein, and increased activity of free sRANKL and OPG.

CONCLUSION

Bone disease that accompanies CD at diagnosis suggests that bone metabolism is affected by the underlying inflammatory process per se, as probably confirmed by our finding of the central proinflammatory cytokine TNF-alpha being strongly associated with the osteoclastogenic mediator RANKL, and inversely with bone density.

Improvement in biomarkers of bone formation during infliximab therapy in pediatric Crohn's disease: results of the REACH study

BACKGROUND & AIMS

Crohn's disease (CD) is associated with altered bone metabolism. This study examined changes in bone formation and resorption after infliximab induction and associations between bone biomarkers, linear growth, and disease activity (Pediatric Crohn's Disease Activity Index [PCDAI]) after 54 weeks of infliximab therapy.

METHODS

One hundred twelve subjects ages 6-17 years with moderate to severe CD received infliximab induction (5 mg/kg/dose) at weeks 0, 2, and 6; week-10 responders were randomized to infliximab every 8 or every 12 weeks maintenance therapy. Serum bone-specific alkaline phosphatase (BSAP), N-terminal propeptide of type 1 collagen (P1NP), urine C-telopeptide of collagen cross-links (CTX-1), and deoxypyrodinoline (DPD) were collected at baseline and 10 weeks. PCDAI and height z-scores were assessed at baseline and at 10 and 54 weeks.

RESULTS

Models were adjusted for bone age, gender, height, and steroid use. Baseline BSAP and P1NP levels were negatively associated with PCDAI (both P = .01). BSAP and P1NP increased during induction (both P < .001) and were associated with 54-week increases in height z-score (P < .05 and P < .001, respectively). Improvements in P1NP were associated with 54-week decreases in PCDAI (P = .01). CTX-1 and DPD also increased during induction (P < .001 and P = .01, respectively) but were not associated with changes in PCDAI. Changes in CTX-1 were associated with improvements in height z-score (P < .002).

CONCLUSIONS

Infliximab therapy is associated with dramatic increases in BSAP and P1NP, consistent with inhibition of tumor necrosis factor-alpha effects on osteoblasts. The increases in CTX-1 and DPD likely reflect coupling of bone formation and resorption and increases in linear growth.

Sarcopenia is prevalent in patients with Crohn's disease in clinical remission

BACKGROUND

Patients with Crohn's disease (CD) are prone to osteoporosis. A loss of muscle mass, called sarcopenia, is responsible for an increased risk of disability. Many factors associated with osteopenia also decrease muscle mass. The aim of the present study was to measure the prevalence of sarcopenia in CD patients in remission and uncover its relationship with osteopenia.

METHODS

In all, 82 CD patients (43 female/39 male; 36 +/- 14 years; body mass index [BMI] 21.1 +/- 3.4) and 50 healthy volunteers (30F/20M; 39 +/- 13 years; BMI 22.2 +/- 2.5) were studied. Body composition was assessed using dual-energy x-ray absorptiometry. Sarcopenia was defined as an appendicular skeletal muscle index (ASMI) below 5.45 kg/m(2) for women and 7.26 for men. Osteopenia was defined as a T-score for bone mineral density (BMD) (g/cm(2)) below -1.0.

RESULTS

In all, 60% of CD patients were found to be sarcopenic and 30% osteopenic, compared to 16% and 4% of controls, respectively (P < 0.01). ASMI was significantly lower in patients than in controls (6.0 +/- 1.1 versus 6.5 +/- 1.2; P < 0.05). Sarcopenic patients had significantly (P < 0.01) lower BMI (20.0 +/- 3.5 versus 22.7 +/- 2.8 kg/m(2)), lean mass (41.5 +/- 9.1 versus 48.1 +/- 9.1 kg), and BMD (1.09 +/- 0.12 versus 1.15 +/- 0.08 g/cm(2)) than nonsarcopenic patients; 91% of sarcopenic patients were also osteopenic. ASMI correlated with BMD (r = 0.46; P < 0.01) and BMI (r = 0.38; P < 0.01).

CONCLUSIONS

The prevalence of sarcopenia is high in young CD patients and strongly related to osteopenia. These 2 phenomena may share similar mechanisms. Simultaneous screening for sarcopenia and osteopenia may be useful in CD patients.

Interpretation of biomarkers of bone metabolism in children: impact of growth velocity and body size in healthy children and chronic disease

OBJECTIVES

To determine the effects of growth, maturation, and whole body bone mineral content (WB-BMC) accrual on biomarkers of bone formation (bone-specific alkaline phosphatase [BSAP]) and resorption (urine deoxypyridinoline/creatinine [DPD]) in healthy children and children with Crohn's disease.

STUDY DESIGN

BSAP and DPD were measured at baseline, with growth and dual energy x-ray absorptiometry (DXA) WB-BMC measured at baseline and 6 months in 202 control subjects and 110 subjects with Crohn's disease, ages 5 to 21 years. Multivariable linear regression identified determinants of biomarkers in control subjects and subjects with Crohn's disease.

RESULTS

In control subjects, BSAP and DPD were significantly and independently associated with sex, Tanner stage, WB-BMC, height velocity, and WB-BMC accrual rates; these covariates explained 77% to 80% of the variability in the bone biomarkers, respectively. Subjects with Crohn's disease had lower height-for-age (P < .001) and WB-BMC-for-height (P <.05) than control subjects. Crohn's disease was associated with lower BSAP (P < .001) and greater DPD (P < .001), independent of growth, maturation, baseline WB-BMC, and WB-BMC accrual, compared with control subjects.

CONCLUSIONS

These data illustrate the potential confounding effects of growth and WB-BMC on bone metabolism biomarkers in children. After adjustment for these effects, Crohn's disease was associated with lower biomarkers of bone formation and greater bone resorption.

Guidelines for the management of growth failure in childhood inflammatory bowel disease

Around 1 in 4 patients with inflammatory bowel disease (IBD) present in childhood, the majority around the time of their pubertal growth spurt. This presents challenges over and above those of managing IBD in adults as this period is a time of dramatic psychological and physical transition for a child. Growth and nutrition are key priorities in the management of adolescents and young adults with IBD. Growth failure in IBD is characterized by delayed skeletal maturation and a delayed onset of puberty, and is best described in terms of height-for-age standard deviation score (Z score) or by variations in growth velocity over a period of 3-4 months. Growth failure is common at presentation in Crohn's disease (CD), but less common in ulcerative colitis (UC). The etiology of growth failure is multifactorial. Principal determinants, however, include the inflammatory process per se, with proinflammatory cytokines (e.g., IL-1beta, IL-6) being directly implicated. Furthermore, poor nutrition and the consequences of prolonged corticosteroid use also contribute to the significant reduction in final adult height of almost 1 in 5 children. Initially a prompt, where possible steroid-free, induction of remission is indicated. The ideal is then to sustain a relapse-free remission until growth is complete, which is often not until early adulthood. These goals can often be achieved with a combination of exclusive enteral nutrition (EEN) and early use of immunosuppressants. The advent of potent and efficacious biological agents considerably improves the range of growth-sparing interventions available to children around puberty, although well-timed surgery remains another highly effective means of achieving remission and significant catch-up growth. We carried out a systematic review of publications to identify the best available evidence for managing growth failure in children with IBD. Despite the paucity of high-quality publications, sufficient data were available in the literature to allow practical, evidence-based where possible, management guidelines to be formulated. Although there is clear evidence that exclusive enteral nutrition achieves mucosal healing, its effect on growth has only been assessed at 6 months. In contrast to corticosteroids, EEN has no negative effect on growth. Corticosteroids remain the key therapy responsible for medication-induced growth impairment, although the use of budesonide in selected patients may minimize the steroid effect on dividing growth plates. Immunosuppressants have become a mainstay of treatment in children with IBD, and are being used earlier in the disease course than ever before. However, there are currently no long-term data reporting better growth outcome if these agents are introduced very soon after diagnosis. In comparison, recent data from a large prospective trial of infliximab in children with moderate to severe CD suggested significant catch-up growth during the first year of regular infusions. The only other intervention that has documented clear catch-up growth has been surgical resection. Resection of localized CD, in otherwise treatment-resistant children, early in the disease process achieves clear catch-up growth within the next 6 months. There are no data available that growth hormone improves final adult height in children with CD. In conjunction with expert endocrinological support, pubertal delay, more common in boys, may be treated with parenteral testosterone if causing significant psychological problems. The optimal management of children and adolescents requires a multidisciplinary approach frequently available within the pediatric healthcare setting. Dedicated dietetic support, along with nurse-specialist, child psychologist, and with closely linked medical and surgical care will likely achieve the best possible start for children facing a lifetime of chronic gut disease.

Systematic review: nutritional therapy in paediatric Crohn's disease

BACKGROUND

At least 25% of individuals diagnosed with Crohn's disease (CD) have onset of disease in childhood. Almost all children with CD have nutritional impairments, such as weight loss or stunting, at diagnosis or subsequently. Nutritional therapy (exclusive enteral nutrition) is established as a valid and effective treatment in paediatric CD. The advantages of this approach are induction of remission and control of inflammatory changes, mucosal healing, positive benefits to growth and overall nutritional status, and avoidance of other medical therapies.

AIM

To provide a comprehensive up-to-date review of the roles of nutritional therapy in CD and of the data supporting this therapy.

METHODS

A search of PubMed was performed with search terms 'enteral nutrition', 'nutritional therapy', 'Crohn disease' and 'children'. Relevant articles were selected from this search. In addition, the reference lists of available articles were reviewed for further relevant articles.

RESULTS

Nutritional therapy offers numerous benefits in the management of CD. Recent work has begun to elucidate the likely mechanisms of this therapy. These include direct mucosal anti-inflammatory effects and alteration of intestinal microflora.

CONCLUSION

Further studies are required to define longer-term effects of nutritional therapy in patients with CD.

Specific considerations in the treatment of pediatric inflammatory bowel disease

Inflammatory bowel disease is one of the most prevalent chronic inflammatory disorders and commonly presents during childhood or adolescence. Occurring during a critical period of growth and development, pediatric Crohn's disease and ulcerative colitis require special consideration. Children often experience growth failure, malnutrition, pubertal delay and bone demineralization. Medical treatment must be optimized to promote clinical improvement and reverse growth failure with minimal toxicity. In addition to pharmacologic and surgical interventions, nutritional therapies play a vital role in the management of pediatric inflammatory bowel disease. This review will outline the epidemiology and clinical complications that are unique to pediatric inflammatory bowel disease, current trends, and recent advances in nutritional and pharmacologic treatment, and projected future therapeutic direction.

Improvement of lumbar bone mass after infliximab therapy in Crohn's disease patients

BACKGROUND

Patients with Crohn's disease (CD) have a high risk of developing osteoporosis, but the mechanisms underlying bone mass loss are unclear. Elevated proinflammatory cytokines, such as tumour necrosis factor-alpha (TNFalpha), have been implicated in the pathogenesis of bone resorption.

AIM

To assess whether suppression of TNFalpha with infliximab treatment has a beneficial effect on lumbar bone mass.

METHODS

Adult CD patients who had received infliximab treatment, and who underwent lumbar densitometric evaluation before and during treatment, were selected. Adult CD patients who had never received infliximab treatment were selected as controls. Information regarding age, sex, weight, duration of CD, use of glucocorticoids and bisphosphonates, and signs of disease activity between both densitometric measurements were collected.

RESULTS

Data from 45 patients were analyzed. The control group (n=30, mean [+/- SD] 26.7+/-9 years of age) had a significantly higher increase in body weight between both evaluations (6.26%+/-8%) than the infliximab group (n=15, 30.6+/-13 years), which had an increase of 0.3%+/-7.4%. There was a strong correlation between the final weight and lumbar bone mineral content (BMC) in both groups. The infliximab group had a significant increase in lumbar bone area (4.15%+/-6.6%), BMC (12.8%+/-13.6%) and bone mineral density (8.13%+/-7.7%) between both evaluations (interval 22.6+/-11 months) compared with the control group. The increase in BMC in patients who had received infliximab treatment was significant when compared with control patients who had received glucocorticoids (n=8) or had evidence of disease activity (n=13).

CONCLUSION

Infliximab therapy improved lumbar bone mass independent of nutritional status. This finding suggests that TNFalpha plays a role in bone loss in CD.

Anti-TNF antibodies: lessons from the past, roadmap for the future

Tumor necrosis factor alpha (TNF) is an important cell-signaling component of the immune system. Since its discovery over 20 years ago, much has been learned about its functions under normal and disease conditions. Nonclinical studies suggested a role for TNF in chronic immune-mediated inflammatory diseases, such as rheumatoid arthritis, Crohn's disease, and psoriasis, and therefore neutralizing monoclonal antibodies specific to human TNF were developed for clinical evaluation. Treatment with anti-TNF monoclonal antibodies (infliximab, adalimumab, and certolizumab pegol) has been shown to provide substantial benefit to patients through reductions in both localized and systemic expression of markers associated with inflammation. In addition, there are beneficial effects of anti-TNF treatment on markers of bone and cartilage turnover. Further exploration of changes in these markers and their correlation with clinical measures of efficacy will be required to allow accurate prediction of those patients most in need of these treatments. Both the clinical and commercial experience with these anti-TNF antibodies provide a wealth of information regarding their pharmacological effects in humans.

Glucocorticoid-induced osteoporosis in children: impact of the underlying disease

Glucocorticoids inhibit osteoblasts through multiple mechanisms, which results in significant reductions in bone formation. The growing skeleton may be especially vulnerable to adverse glucocorticoid effects on bone formation, which could possibly compromise trabecular and cortical bone accretion. Although decreased bone mineral density has been described in various pediatric disorders that require glucocorticoids, and a population-based study reported increased fracture risk in children who require >4 courses of glucocorticoids, some of the detrimental bone effects attributed to glucocorticoids may be caused by the underlying inflammatory disease. For example, inflammatory cytokines that are elevated in chronic disease, such as tumor necrosis factor alpha, suppress bone formation and promote bone resorption through mechanisms similar to glucocorticoid-induced osteoporosis. Summarized in this review are changes in bone density and dimensions during growth, the effects of glucocorticoids and cytokines on bone cells, the potential confounding effects of the underlying inflammatory-disease process, and the challenges in interpreting dual-energy x-ray absorptiometry results in children with altered growth and development in the setting of glucocorticoid therapy. Two recent studies of children treated with chronic glucocorticoids highlight the differences in the effect of underlying disease, as well as the importance of associated alterations in growth and development.

The effect of anti-TNF-alpha therapy on spinal bone mineral density in patients with Crohn's disease

Proinflammatory cytokines, including tumor necrosis factor-alpha (TNF-alpha) might be, at least partially, responsible for the development of osteopenia or osteoporosis in Crohn's disease. We investigated whether anti-TNF therapy for Crohn's disease could have any skeletal impact. Therefore, we studied the effects of infliximab, a monoclonal antibody against TNF-alpha with and without bisphosphonates, on spinal bone mineral density (BMD). The effect of corticosteroids was also analyzed. A retrospective cohort analysis was performed on 61 patients with Crohn's disease and low BMD by serial DXA scans. Twenty-three patients were on infliximab and 36 patients were on bisphosphonates. Mean duration between DXA scans was 2.2 +/- 0.99 years. After controlling for corticosteroid use, patients with concurrent infliximab and bisphosphonate treatment exhibited a greater increase in BMD compared to those on bisphosphonates alone (+6.7%/year vs. +4.46%/year, P= 0.045); corticosteroids inhibited this effect (P= 0.025). However, infliximab alone had no effects on BMD. Patients receiving bisphosphonates showed a significant increase in lumbar spine BMD compared to those not on bisphosphonates (+3.97% change in T score/year vs. -3.68%/year, P < 0.0001). Concurrent corticosteroid use significantly inhibited this effect (+2.15%/year vs. +4.97%/year, P= 0.0014). Concurrent infliximab use may confer an additional benefit to that already documented for bisphosphonate use alone; bisphosphonates are beneficial in the treatment of low BMD in patients with Crohn's disease, though corticosteroids may partially inhibit this effect.

Prevention and treatment of osteoporosis in inflammatory bowel disease

The following are guidelines for evaluation and consideration for treatment of patients with inflammatory bone disease (IBD) after bone mineral density (BMD) measurements. The Crohn's & Colitis Foundation of America (CCFA) has indicated that its recommendations are intended to serve as reference points for clinical decision-making, not as rigid standards, limits, or rules. They should not be interpreted as quality standards.