Somatomedin-C levels in growth-impaired children and adolescents with chronic inflammatory bowel disease

Chronic inflammation and the growth hormone/insulin-like growth factor-1 axis

Interactions between growth hormone (GH), insulin-like growth factor-1 (IGF-1), and the immune system are complex, bidirectional, but not fully explained. Current reviews based on numerous studies have indicated that chronic inflammation could suppress the GH/IGF-1 axis via several mechanisms such as relative GH and/or IGF-1 insufficiency, peripheral resistance to GH and/or IGF-1 resulting from down-regulation of GH and IGF-1 receptors, disruption in the GH/IGF-1 signalling pathways, dysregulation of IGF binding proteins (IGFBPs), reduced IGF bioavailability, and modified gene regulation due to changes in the microRNA system. It is well-known that relationships between the immune system and the GH/IGF-1 axis are mutual and GH as well as IGF-1 could modulate inflammatory response and the activity of systemic inflammation. Available data indicate that the GH/IGF-1 axis exerts both pro-inflammatory and anti-inflammatory effects. Pro-inflammatory cytokines such as interleukin-6 (IL-6), tumour necrosis factor-a (TNF-α), and interleukin-1b (IL-b) are some of the most significant factors, besides malnutrition, chronic stress, and prolonged use of glucocorticoids, which impair the activity of the GH/IGF-1 axis, and consequently lead to growth retardation in children suffering from childhood-onset chronic inflammatory diseases. In this review, we discuss the mechanisms underlying the impact of chronic inflammation on the GH/IGF-1 axis and growth processes during childhood and adolescence, based on a number of experimental and human studies.

Growth Hormone Resistance-Special Focus on Inflammatory Bowel Disease

Growth hormone (GH) plays major anabolic and catabolic roles in the body and is important for regulating several aspects of growth. During an inflammatory process, cells may develop a state of GH resistance during which their response to GH stimulation is limited. In this review, we will emphasize specific mechanisms governing the formation of GH resistance in the active phase of inflammatory bowel disease. The specific molecular effects mediated through individual inflammatory mediators and processes will be highlighted to provide an overview of the transcriptional, translational and post-translational inflammation-mediated impacts on the GH receptor (GHR) along with the impacts on GH-induced intracellular signaling. We also will review GH’s effects on mucosal healing and immune cells in the context of experimental colitis, human inflammatory bowel disease and in patients with short bowel syndrome.

Growth and the Growth Hormone-Insulin Like Growth Factor 1 Axis in Children With Chronic Inflammation: Current Evidence, Gaps in Knowledge, and Future Directions

Growth failure is frequently encountered in children with chronic inflammatory conditions like juvenile idiopathic arthritis, inflammatory bowel disease, and cystic fibrosis. Delayed puberty and attenuated pubertal growth spurt are often seen during adolescence. The underlying inflammatory state mediated by proinflammatory cytokines, prolonged use of glucocorticoid, and suboptimal nutrition contribute to growth failure and pubertal abnormalities. These factors can impair growth by their effects on the GH-IGF axis and also directly at the level of the growth plate via alterations in chondrogenesis and local growth factor signaling. Recent studies on the impact of cytokines and glucocorticoid on the growth plate further advanced our understanding of growth failure in chronic disease and provided a biological rationale of growth promotion. Targeting cytokines using biological therapy may lead to improvement of growth in some of these children, but approximately one-third continue to grow slowly. There is increasing evidence that the use of relatively high-dose recombinant human GH may lead to partial catch-up growth in chronic inflammatory conditions, although long-term follow-up data are currently limited. In this review, we comprehensively review the growth abnormalities in children with juvenile idiopathic arthritis, inflammatory bowel disease, and cystic fibrosis, systemic abnormalities of the GH-IGF axis, and growth plate perturbations. We also systematically reviewed all the current published studies of recombinant human GH in these conditions and discussed the role of recombinant human IGF-1.

Mesalazine in the initial management of severely acutely malnourished children with environmental enteric dysfunction: a pilot randomized controlled trial

BACKGROUND

Environmental enteric dysfunction (EED) is an acquired syndrome of impaired gastrointestinal mucosal barrier function that is thought to play a key role in the pathogenesis of stunting in early life. It has been conceptualized as an adaptive response to excess environmental pathogen exposure. However, it is clinically similar to other inflammatory enteropathies, which result from both host and environmental triggers, and for which immunomodulation is a cornerstone of therapy.

METHODS

In this pilot double-blind randomized placebo-controlled trial, 44 children with severe acute malnutrition and evidence of EED were assigned to treatment with mesalazine or placebo for 28 days during nutritional rehabilitation. Primary outcomes were safety and acceptability of the intervention.

RESULTS

Treatment with mesalazine was safe: there was no excess of adverse events, evidence of deterioration in intestinal barrier integrity or impact on nutritional recovery. There were modest reductions in several inflammatory markers with mesalazine compared to placebo. Depression of the growth hormone--insulin-like growth factor-1 axis was evident at enrollment and associated with inflammatory activation. Increases in the former and decreases in the latter correlated with linear growth.

CONCLUSIONS

Intestinal inflammation in EED is non-essential for mucosal homeostasis and is at least partly maladaptive. Further trials of gut-specific immunomodulatory therapies targeting host inflammatory activation in order to optimize the growth benefits of nutritional rehabilitation and to address stunting are warranted. Funded by The Wellcome Trust.

TRIAL REGISTRATION

Registered at Clinicaltrials.gov NCT01841099.

Potential role of IGF-1 z score to predict permanent linear growth impairment in children with IBD

In this pilot study, we analyzed serum insulin-like growth factor 1 (IGF-1)- and IGF-binding protein-3-for-age z scores from 54 inflammatory bowel disease children with no, temporary, or permanent growth impairment. Although our findings did not reach statistical significance, patients with permanent linear growth impairment had lower IGF-1-for-age z scores (-1.76 [-2.25 to -0.43]) compared with those with no or temporary growth impairment (-0.84 [-1.49 to -0.3]) and -1.16 [-1.59 to -1.51], respectively). IGF-binding protein-3 levels were similar across the 3 groups. In the absence of significant inflammation and malnutrition, lower IGF-1-for-age z scores may help distinguish patients likely to have permanent growth impairment from those whose growth impairment is likely to be temporary.

IGF-1, the cross road of the nutritional, inflammatory and hormonal pathways to frailty

The decline in functional capacity is a heterogeneous phenomenon in the elderly. An accelerated ageing determines a frail status. It results in an increased vulnerability to stressors for decreased physiological reserves. The early identification of a frail status is essential for preventing loss of functional capacity, and its clinical consequences. Frailty and mobility limitation result from an interplay of different pathways including multiple anabolic deficiency, inflammation, oxidative stress, and a poor nutritional status. However, the age-related decline in insulin-like growth factor 1 (IGF-1) bioactivity deserves special attention as it could represent the ideal crossroad of endocrine, inflammatory, and nutritional pathways to frailty. Several minerals, namely magnesium, selenium, and zinc, appear to be important determinants of IGF-1 bioactivity. This review aims to provide an overview of the potential usefulness of nutrients modulating IGF-1 as potential therapeutic targets in the prevention of mobility limitation occurring in frail older subjects.

Insulin-like growth factor-I (IGF-I) and clinical nutrition

IGF-I (insulin-like growth factor-I) is a peptide hormone, produced predominantly by the liver in response to pituitary GH (growth hormone), which is involved in a wide variety of physiological processes. It acts in an endocrine, paracrine and autocrine manner to promote growth. The production of IGF-I signals the availability of nutrients needed for its anabolic actions. Recently, there has been growing interest in its role in health and disease. IGF-I has long been known to be regulated by nutrition and dysregulated in states of under- and over-nutrition, its serum concentrations falling in malnutrition and responding promptly to refeeding. This has led to interest in its utility as a nutritional biomarker. A considerable evidence base supports utility for measurement of IGF-I in nutritional contexts. Its concentration may be valuable in providing information on nutritional status, prognosis and in monitoring nutritional support. However, it is insufficiently specific for use as a screening test for under nutrition as its serum concentration is influenced by many factors other than nutritional status, notably the APR (acute-phase response) and endocrine conditions. Concentrations should be interpreted along with clinical findings and the results of other investigations such as CRP (C-reactive protein). More recently, there has been interest in free IGF-I which holds promise as a nutritional marker. The present review covers nutritional regulation of IGF-I and its dysregulation in disease, then goes on to review recent studies supporting its utility as a nutritional marker in clinical contexts. Although not currently recommended by clinical guidelines, it is likely that, in time, measurement of IGF-I will become a routine part of nutritional assessment in a number of these contexts.

Mathematical modelling to restore circulating IGF-1 concentrations in children with Crohn's disease-induced growth failure: a pharmacokinetic study

OBJECTIVES

Children with Crohn's disease grow poorly, and inflammation depresses the response of insulin-like growth factor-1 (IGF-1) to growth hormone. Correcting the inflammation normalises growth velocity; however, removing inflammation cannot be achieved in all children. Our lack of understanding of IGF-1 kinetics has hampered its use, particularly as high IGF-1 concentrations over long periods may predispose to colon cancer. We hypothesised that mathematical modelling of IGF-1 would define dosing regimes that return IGF-1 concentrations into the normal range, without reaching values that risk cancer.

DESIGN

Pharmacokinetic intervention study.

SETTING

Tertiary paediatric gastroenterology unit.

PARTICIPANTS

8 children (M:F; 4:4) entered the study. All completed: 5 South Asian British; 2 White British; 1 African British.

INCLUSION CRITERIA

Children over 10 years with active Crohn's disease (C reactive protein >10 mg/l or erythrocyte sedimentation rate >25 mm/h) and height velocity <-2 SD score.

EXCLUSION CRITERIA

closed epiphyses; corticosteroids within 3 months; neoplasia or known hypersensitivity to recombinant human IGF-1 (rhIGF-1).

INTERVENTIONS

Subcutaneous rhIGF-1 (120 μg/kg) per dose over two admissions: the first as a single dose and the second as twice daily doses over 5 days.

PRIMARY OUTCOME

Significant increase in circulating IGF-1.

SECONDARY OUTCOMES

Incidence of side effects of IGF-1. A mathematical model of circulating IGF-1 (Ac) was developed to include parameters of endogenous synthesis (Ksyn); exogenous uptake (Ka) from the subcutaneous dose (As): and IGF-1 clearance: where dAc/dt=Ksyn - Kout×Ac+Ka×As.

RESULTS

Subcutaneous IGF-1 increased concentrations, which were maintained on twice daily doses. In covariate analysis, disease activity reduced Ksyn (p<0.001). Optimal dosing was derived from least squares regression fitted to a dataset of 384 Crohn's patients, with model parameters assigned by simulation.

CONCLUSIONS

By using age, weight and disease activity scaling in IGF-1 dosing, over 95% of children will have normalised IGF-1 concentrations below +2.5 SDs of the normal population mean, a level not associated with cancer risk.

Sex differences in statural growth impairment in Crohn's disease: role of IGF-1

BACKGROUND

Growth impairment in Crohn's disease (CD) is more common in males than females for unknown reasons. Since insulin-like growth factor-1 (IGF-1) is important for statural growth, we hypothesized that IGF-1 levels are lower in males with CD.

METHODS

Sex differences in hormone Z-scores based on chronological age (CA-Z) and bone age (BA-Z) were examined in a cross-sectional study of 82 CD patients <21 years of age (43% female).

RESULTS

IGF-1 CA-Z and BA-Z-scores were 0.50 units (P = 0.04) and 1.24 units (P = 0.003) lower in males. Mean bone age (12.2 years) was lower than chronological age (13.1 years) (P < 0.0001). Erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), and albumin did not differ by sex (P ≥ 0.08), but were associated with IGF-1 CA-Z and BA-Z-scores (P ≤ 0.02). Insulin-like growth factor binding protein-3 (IGFBP-3) CA-Z and BA-Z-scores were 0.71 units (P = 0.004) and 1.26 units (P < 0.001) lower in males. Inflammatory markers were correlated with sex hormone CA-Z and BA-Z and pituitary hormone BA-Z-scores in males (P ≤ 0.03), but not females (P ≥ 0.25). IGF-1 BA-Z-scores were positively associated with height BA-Z-scores (P = 0.03). Mean height BA-Z-scores were lower in males (P = 0.03).

CONCLUSIONS

Lower IGF-1 levels in males may explain sex differences in growth impairment in CD. Inflammation appears to more adversely affect hormone levels and statural growth in males. Prospective longitudinal studies are needed to further clarify the role of IGF-1 in sex differences in statural growth impairment in pediatric CD.

The role of growth hormone and insulin-like growth factor-1 in Crohn's disease: implications for therapeutic use of human growth hormone in pediatric patients

PURPOSE OF REVIEW

This review evaluates the role of the growth hormone (GH) and insulin-like growth factor (IGF) in influencing linear growth in pediatric Crohn's disease. It also examines the current evidence concerning the use of recombinant human growth hormone (rhGH) as a potential therapy in achieving optimal growth and inducing mucosal healing for pediatric Crohn's disease.

RECENT FINDINGS

Current treatment strategies for Crohn's disease including antitumor necrosis factor-α (TNF-α) therapy have been demonstrated to improve growth velocity, but linear growth deficits persist despite optimization of therapy. By complex mechanisms, including the reduction of levels of IGF-1 and induction of systemic and hepatic GH resistance, cytokines such as TNF-α and interleukin-6 (IL-6), commonly elevated in active Crohn's disease, are important as mediators of linear growth delay. Recent evidence suggests that rhGH therapy is effective in improving short-term linear growth for a selected group of patients but of limited benefit as a therapy for improving mucosal disease and reducing clinical disease activity.

SUMMARY

Crohn's disease interacts with the GH-IGF-1 axis in important ways. Recent studies evaluating rhGH use in pediatric Crohn's disease have demonstrated some efficacy in reversing persistent linear growth delay but limited benefits in terms of improving mucosal disease and clinical disease activity. Larger studies of adequate power are needed to confirm a true benefit in terms of growth, to examine a potential benefit with regard to modification of disease activity, and to evaluate long-term risks.

Association of insulin-like growth factor-1 with thyroid nodules

The aim of the present study was to investigate the relationship between insulin-like growth factor-1 (IGF-1) and thyroid nodules. A total of 56 patients with thyroid nodules confirmed by physical examination and ultrasound screening were randomly selected. The patients were divided into three groups by radionuclide scan: the hot nodule group (group 1, n=18); the cold and solid nodule group (group 2, n=18); and the cold and cystic nodule group (group 3, n=20). Cystic fluid samples from patients with cystic cold thyroid nodules were defined as group 4. A control group of 18 healthy adults matched for age, gender and body mass index (group 0) was also included. For all participants, levels of the thyroid hormones, TT3, TT4, TSH and IGF-1, were determined by radioimmunoassay. The measurement data were expressed as the mean ± standard deviation (SD). The analysis of variance was performed by the t-test and the correlation analysis was performed by linear regression. The serum levels of IGF-1 in the solid cold nodule group were significantly higher than those in the hot nodule group (P<0.05). Serum levels of IGF-1 in the cystic cold nodule group were significantly lower than those in the control group (P<0.05). The serum IGF-1 levels in the cystic fluid were significantly lower than those in the cystic cold nodule (P<0.05) and the control groups (P<0.05). Additionally, the mean serum IGF-1 level in patients with thyroid adenoma was significantly higher than that in the control group (P<0.05). The serum IGF-1 level may not be involved in the pathogenesis of hot thyroid nodules and cold and cystic thyroid nodules; however, it may play a significant role in the pathogenesis of certain solid cold thyroid nodules.

Insulin-like growth factor-I regulation of immune function: a potential therapeutic target in autoimmune diseases?

This topically limited review explores the relationship between the immune system and insulin-like growth factors (IGF-I and IGF-II) and the proteins through which they act, including IGF-I receptor (IGF-IR) and the IGF-I binding proteins. The IGF/IGF-IR pathway plays important and diverse roles in tissue development and function. It regulates cell cycle progression, apoptosis, and the translation of proteins. Many of the consequences ascribed to IGF-IR activation result from its association with several accessory proteins that are either identical or closely related to those involved in insulin receptor signaling. Relatively recent awareness that IGF-I and IGF-IR regulate immune function has cast this pathway in an unexpected light; it may represent an important switch governing the quality and amplitude of immune responses. IGF-I/IGF-IR signaling may also participate in the pathogenesis of autoimmune diseases, although its relationship with these processes seems complex and relatively unexplored. On the one hand, IGF-I seems to protect experimental animals from developing insulin-deficient diabetes mellitus. In contrast, activating antibodies directed at IGF-IR have been detected in patients with Graves' disease, where the receptor is overexpressed by multiple cell types. The frequency of IGF-IR+ B and T cells is substantially increased in patients with that disease. Potential involvement of IGF-I and IGF-IR in the pathogenesis of autoimmune diseases suggests that this pathway might constitute an attractive therapeutic target. IGF-IR has been targeted in efforts directed toward drug development for cancer, employing both small-molecule and monoclonal antibody approaches. These have been generally well-tolerated. Recognizing the broader role of IGF-IR in regulating both normal and pathological immune responses may offer important opportunities for therapeutic intervention in several allied diseases that have proven particularly difficult to treat.

Serum IGF-I and C-reactive protein in healthy black and white young men: the CARDIA male hormone study

OBJECTIVE

Animal and human studies suggest that C-reactive protein (CRP) may be inversely associated with serum insulin-like growth factor-I (IGF-I) concentrations. However, most human studies have not controlled adequately for confounding factors, particularly nutritional intake. This population-based study examined whether CRP is inversely associated with IGF-I and IGFBP-3 concentrations.

METHODS

In cross-sectional analysis, multivariable linear regression with adjustment for age, BMI, smoking status, alcohol intake, and nutritional factors was used to relate log CRP, the independent variable, to IGF-I and IGFBP-3 in a sample of black (n=364) and white men (n=486) separately by race.

RESULTS

Only black men had positive findings: log CRP was significantly associated with IGF-I (beta=-13.1 ng/ml, p=0.02) and the difference in mean IGF-I concentrations between the highest and lowest quartiles of CRP was 26 ng/ml. There was a statistically significant interaction between log CRP and smoking status (p=0.02); the regression coefficient for IGF-I predicted from log CRP was significant in smokers (beta=-39.8 ng/ml, p=0.0001), but not in non-smokers. The difference in mean IGF-I concentrations between highest and lowest quartiles of CRP was 100 ng/ml for black smokers. There were no associations for IGFBP-3.

CONCLUSIONS

In our study, CRP levels are inversely associated with IGF-I concentrations in black male smokers; however, the causal nature of the association is unclear and should be studied further.

Mechanisms of growth impairment in pediatric Crohn's disease

Crohn's disease manifests during childhood or adolescence in up to 25% of patients. The potential for linear growth impairment as a complication of chronic intestinal inflammation is unique to pediatric patient populations. Insulin-like growth factor I (IGF-I), produced by the liver in response to growth hormone (GH) stimulation, is the key mediator of GH effects at the growth plate of bones. An association between impaired growth in children with Crohn's disease and low IGF-I levels is well recognized. Early studies emphasized the role of malnutrition in suppression of IGF-I production. However, a simple nutritional hypothesis fails to explain all the observations related to growth in children with Crohn's disease. The direct, growth-inhibitory effects of proinflammatory cytokines are increasingly recognized and explored. The potential role of noncytokine factors, such as lipopolysaccharides, and their potential to negatively influence the growth axis have recently been investigated with intriguing results. There is now reason for optimism that the modern anticytokine therapeutic agents available for treating children and adolescents with Crohn's disease will reduce the prevalence of this otherwise common complication. As our understanding of the mechanisms that underlie growth impairment advance, so too should the opportunity for developing further novel and targeted therapies.

A two-year longitudinal study of persistent lean tissue deficits in children with Crohn's disease

BACKGROUND & AIMS

Deficits in lean body mass have been reported in cross-sectional studies of children with Crohn's disease, but no longitudinal data exist from diagnosis. We observed the effects of Crohn's disease on body composition and bone mineral content (BMC), beginning at diagnosis and followed prospectively for 2 years.

METHODS

The study was conducted at 2 tertiary care centers for pediatric inflammatory bowel diseases. At diagnosis we recorded age, weight, height, levels of serum interleukin-6 and insulin-like growth factor-1, sexual maturation stage, disease activity, z scores for body mass index (BMI), fat-free mass (FFM), and bone mineral content (BMC). z Scores were adjusted for height and age, when appropriate. Measurements were made yearly in patients with Crohn's disease (n = 42) but only at the start of the study in controls (n = 81).

RESULTS

BMI and FFM z scores were significantly reduced at the time of diagnosis in children with Crohn's disease, compared with controls. During the 2-year study period, the BMI z scores normalized in patients with Crohn's disease, but the FFM z scores did not increase significantly. The BMC z scores increased significantly, but they were still lower than control values after 2 years. Changes in BMC during a period of 2 years were associated with increases in FFM (R(2) = 0.318, P < .01).

CONCLUSIONS

The correction of BMI that is associated with clinical improvement in children with Crohn's disease 2 years after diagnosis results from gains in fat mass. Significant FFM deficits might hamper normal acquisition of bone mass in children with Crohn's disease because of a lack of mechanical strain.

Gender differences in body composition deficits at diagnosis in children and adolescents with Crohn's disease

BACKGROUND

Childhood Crohn's disease (CD) is associated with poor growth and decreased body mass index (BMI); however, lean mass (LM) and fat mass (FM) deficits prior to therapy have not been characterized.

OBJECTIVES

To quantify LM and FM in incident pediatric CD subjects and controls, and to identify determinants of LM and FM deficits.

METHODS

Whole body LM and FM were assessed using DXA in 78 CD subjects and 669 healthy controls, ages 5-21 yr. Gender specific z-scores for LM (LM-Ht) and FM (FM-Ht) relative to height were derived using log linear regression models in the controls. Multivariate linear regression models adjusted for potential confounders.

RESULTS

CD was associated with significantly lower height and BMI for age. Within CD subjects, FM-Ht and LM-Ht were significantly lower in females compared with males (FM-Ht z: -0.66+/-0.83 vs. -0.08+/-0.95, p<0.01; LM-Ht z: -1.12+/-1.12 vs. -0.57+/-0.99, p<0.05). In females, CD was associated with significantly lower LM-Ht (p<0.001) and FM-Ht (p=0.001), adjusted for age, race and Tanner stage, compared with controls. LM and FM deficits were significantly greater in older females with CD; 47% of adolescent females had LM-Ht<or=5th percentile. In non-black males, CD was also associated with lower LM-Ht (p<0.02); FM-Ht deficits were not significant.

CONCLUSIONS

Incident CD was associated with significant LM deficits in males and females, and FM deficits in females. Future studies are needed to identify etiologies for the age and gender differences and to evaluate therapies for these deficits.

Effect of long-term low-dose prednisone on height velocity and disease activity in pediatric and adolescent patients with Crohn disease

OBJECTIVES

To determine whether long-term low-dose prednisone (LTLDP) therapy has a decelerating effect on growth velocity and whether this therapy is effective in the maintenance of remission in the subgroup of pediatric patients with Crohn disease (CD) who had previously experienced flares on more than 1 occasion when prednisone was discontinued.

PATIENTS AND METHODS

A retrospective chart review of patients was done. Our sample consisted of patients 6 to 17 years of age with CD who had received uninterrupted prednisone at an average daily dose of 0.1 to 0.4 mg x kg(-1) x day(-1) for at least 8 weeks. Their heights were plotted on sex-appropriate growth charts at 4 time points: 1 year before LTLDP, at therapy onset, at therapy discontinuation, and 1 year after therapy was discontinued. The height velocities (HVs) were compared with the normal HV established by Tanner. The disease activities of 2 groups were compared: LTLDP plus azathioprine/6-mercaptopurine (AZA/6-MP) and LTLDP alone.

RESULTS

One hundred two patients were included. The mean age of our sample was 13.7 +/- 2.7 years (standard deviation). The mean dose of prednisone dose was 0.18 +/- 0.07 mg x kg(-1) x day(-1)), for a mean duration of therapy of 14.4 +/- 7.2 months. Throughout the study, 78% of patients had normal HV. Growth deceleration was seen in 19% of patients with prior normal growth. Of this group, 31% had "catch-up" growth 1 year after prednisone was discontinued; the remaining 69% did not. Catch-up growth was more likely in patients who had reached the expected age peak HV, which is defined as 12.5 years for girls and 13.5 years for boys (P = 0.04). In addition, 6 patients reached the peak HV after LTLDP discontinuation; 13 did not. We found no difference in the maintenance of remission rate between the compared groups.

CONCLUSIONS

A minority of our study population had growth deceleration. Age was an important factor for subsequent catch-up growth. LTLDP efficacy to maintain remission was not different from that of LTLDP plus AZA/6-MP; differences in concomitant therapies (eg, antibiotics, infliximab) between the 2 groups were not statistically significant.

Growth retardation in pediatric Crohn's disease: pathogenesis and interventions

Growth retardation (GR) may pose a significant challenge to the quality of life and the proper management of children and adolescents with Crohn's disease (CD). It can occur in a significant proportion of patients, and may precede clinical evidence of bowel disease. Current evidence suggests that GR is a complex interaction between nutritional status, inflammation, disease severity, and genotype, which causes resistance to the effects of growth hormone. Recent research has identified a key role for the inflammatory cytokines TNF alpha, IL-6, and IL1 beta. This review summarizes current knowledge as well as gaps in our understanding of the mechanisms involved and the usefulness of the different treatment modalities in promoting growth in CD patients.

The insulin-like growth factor (IGF) system and its relation to infliximab treatment in adult patients with Crohn's disease

OBJECTIVE

Metabolic bone disease (MBD) and muscle wasting (MW) are serious complications in adult patients suffering from inflammatory bowel disease. These complications may be caused by alterations in the insulin-like growth factor (IGF) system. The aim of the present study was to assess changes in the IGF system in patients with active Crohn's disease (CD) before and during infliximab treatment.

MATERIAL AND METHODS

We studied 13 patients with therapy refractory CD, treated with infliximab (5 mg/kg body-weight) at baseline and after 2 weeks. The IGF system and markers of inflammation were examined at baseline, on days 2-5 and after 1, 4, and 8 weeks. Ten healthy age- and gender-matched persons served as controls.

RESULTS

Total IGF-I and IGF binding protein (IGFBP)-3 levels were reduced by 36% (p<0.05) and 27% (p<0.001), respectively, compared with those of controls, and normalized during the study period. Free IGF-I levels were reduced by 46% (p<0.05) compared with those of controls and remained suppressed. IGFBP-2 levels were increased at baseline by a factor 2.3 compared to controls (p<0.01) with partial normalization at the end of the study period. The Crohn's disease Activity Index, the Harvey Bradshaw Index, C-reactive protein, orosomucoid and albumin reached normal levels during infliximab treatment.

CONCLUSIONS

Treatment with infliximab normalized circulating levels of total IGF-I and IGFBP-3, and partially normalized IGFBP-2, whereas free IGF-I remained suppressed. We suggest that the changes in the IGF system may be part of the catabolic state in active CD and may have an association with MBD and MW.

The insulin-like growth factor (IGF)-system in active ulcerative colitis and Crohn's disease: relations to disease activity and corticosteroid treatment

BACKGROUND

Metabolic bone disease (MBD) and muscle wasting (MW) are serious complications in adults suffering from inflammatory bowel disease (IBD). The inflammatory process and corticosteroid treatment may lead to changes in the IGF-system associated with MBD and MW.

AIM

To assess changes in the IGF-system and clinical and biochemical markers in ulcerative colitis (UC) and Crohn's disease (CD).

METHODS

We studied 37 IBD patients with severe clinical exacerbation (20 with UC, 17 with CD) before and during high dose corticosteroid treatment and tapering (8-12 weeks).

RESULTS

Total IGF-I was reduced in CD (36% p<0.01) and UC (41% p<0.001) before treatment and normalized completely. Free IGF-I baseline levels were unchanged compared to controls. In UC, free IGF-I levels increased significantly at week 1 and week 4 (p<0.01, respectively). In CD, no changes in free IGF-I levels were observed. IGFBP-2 baseline levels were increased by a factor 2.3 in UC and CD compared to controls (p<0.01 respectively) and normalized during treatment. IGFBP-3 was reduced by 38% (p<0.01) in CD and 32% (p<0.01) in UC with only partial normalization. Harvey-Bradshaw index, C - reactive protein and albumin normalized during treatment.

CONCLUSIONS

Significant changes in total and free IGF-I and IGFBP-2 and IGFBP-3 were demonstrated in CD and UC patients in exacerbation with only partial normalization during high dose corticosteroid treatment and tapering without differences between UC and CD. These changes may be part of MBD and MW in active IBD.

Dietary intake and the insulin-like growth factor system: effects of migration in two related populations in India and Britain with markedly different dietary intake

Background

The insulin-like growth factor (IGF) system is implicated in the pathogenesis of diabetes and cardiovascular disease.

Objective

We report the effects of total energy intake on the IGF system in two populations with markedly different dietary macronutrient intake and cardiovascular event rate.

Design, subjects and setting

Dietary macronutrient intake was measured in a specific Gujarati migrant community in Sandwell, UK (n = 205) compared with people still resident in the same villages of origin in India (n = 246). Fasting IGF-I, IGF-binding protein (IGFBP)-1 and IGFBP-3, insulin and glucose (0 and 2-hour) were measured.

Results

Total energy and total fat intake were higher in UK migrants, as were IGFBP-3 and IGF-I (mean (95% confidence interval): 145.9 (138.1–153.6) vs. 100.9 (94.6–107.3) ng ml-1; F = 76.6, P < 0.001). IGFBP-1 was lower in UK migrants (29.5 (25.9–33.0) vs. 56.5 (50.6–62.5) μg l-1; F = 48.4, P < 0.001). At both sites, IGF-I correlated positively with total energy (Spearman's ρ = 0.45, P < 0.001) and total fat (ρ = 0.44, P < 0.001) as did IGFBP-3 with total energy (ρ = 0.21, P < 0.05) and fat (ρ = 0.26, P < 0.001). Conversely, in Indian Gujaratis, IGFBP-1 fell with increasing total energy (ρ = -0.27, P < 0.001) and fat intake (ρ = -0.26, P < 0.01) but not in UK Gujaratis. Multiple linear regression modelling showed that increasing quartiles of fat intake were associated with higher IGF-I (β = 0.42, P = 0.007) independent of age, body mass index, plasma insulin, fatty acids and 2-hour glucose.

Conclusion

In these genetically similar groups, migration to the UK and adoption of a different diet is associated with marked changes in the IGF system, suggesting that environmental factors profoundly modulate serum concentrations and actions of IGFs.

Intestinal inflammation-induced growth retardation acts through IL-6 in rats and depends on the -174 IL-6 G/C polymorphism in children

Inflammatory diseases frequently impair linear growth. Crohn's disease inhibits growth in up to one third of affected children. In rats with trinitrobenzenesulphonic acid-induced colitis, 40% of growth impairment is attributable to inflammation, with the rest being due to undernutrition. In transgenic mice without inflammation, raised IL-6 retards growth, suppressing insulin-like growth factor (IGF)-I. We hypothesized that IL-6, induced by intestinal inflammation, suppresses growth and inhibits IGF-I expression. Therefore, an anti-IL-6 Ab was given to rats with trinitrobenzene-sulphonic acid colitis. The Ab did not improve nutrient intake or decrease inflammation compared with untreated disease controls, but it significantly restored linear growth (P = 0.023) and increased IGF-I (P = 0.05). In humans, the IL-6 -174 G/C promoter polymorphism affects IL-6 transcription, with the GG genotype inducing the greatest IL-6 levels. Because IL-6 is increased in Crohn's disease, we further hypothesized that growth failure would vary with the IL-6 -174 genotype. At diagnosis, among 153 children with Crohn's disease, those with the IL-6 GG genotype were more growth-retarded than those with the GC or CC genotypes (height SD score, -0.51 vs. -0.10; P = 0.031). Also, the patients with the IL-6 GG genotype had higher circulating levels of C-reactive protein, an IL-6-induced product (36 vs. 18 mg/dl, P = 0.028). However, their risk of developing Crohn's disease was similar to other genotypes when compared with 351 healthy controls (P = 0.7). Thus, the IL-6 -174 genotype mediates growth failure in children with Crohn's disease.

Prise en charge nutritionnelle de la maladie de Crohn chez l'enfant et l'adolescent : bases physiopathologiques et mise en pratique

Growth retardation and delay in sexual maturation are the major complications of child-onset Crohn's disease (CD). Nutritional assessment and monitoring should comprise: weight and height measurement with calculation of respective velocities (growth velocity should be > or = 4-5 cm/year during the prepubertal period); pubertal staging; dietetic evaluation; laboratory analysis for mineral, vitamin and trace element deficiencies; bone age. At diagnosis, weight loss and growth delay are present in 80-90% and 1/3 of cases, respectively. In case of an acute flare-up in a CD child with normal nutritional status, nutritional therapy is limited to oral feeding, with a caloric intake at least equal to recommended dietary allowances for age and sex. A low-fiber diet is advised in case of small bowel stenosis. No diet has been shown as efficient in the long-term maintenance of remission. Exclusive enteral nutrition (EN) is an alternative to corticosteroids for the treatment of an acute flare-up of CD, especially in case of malnutrition. Prolonged nocturnal EN is of great interest for the treatment of growth retardation and delay of sexual maturation and in case of steroid-dependent or steroid-refractory CD. In case of steroid-dependent CD with no delay of growth and/or sexual maturation, immunomodulating agents are nowadays an alternative to long-term EN. Efficacy of polymeric solutions is identical to that of semi-elemental or elemental solutions. Parenteral nutrition is limited to an acute flare-up with resistance to medical treatment and/or EN, and contraindications to surgery; occlusion or fistula; short bowel syndrome.

Growth and adult height in atypical coeliac patients, with or without growth hormone deficiency

OBJECTIVE

To evaluate the effect of a gluten-free diet on growth and adult height, when available, in coeliac children without gastrointestinal symptoms.

PATIENTS AND METHODS

Sixty-one coeliac children without gastro-intestinal symptoms were included in the study. The age at diagnosis was 9.50 +/- 3.3 years. Thirty-eight had short stature at diagnosis (< 10th percentile) and 23 had normal stature. Thirty-seven reached adult height.

RESULTS

After beginning the diet an increase in growth velocity was seen in 30 patients (responders) (20 with initial short stature), while in 31 patients (18 with short stature) there was no catch-up growth (non-responders). Bone age at diagnosis was significantly more delayed in the responders than in the non-responders. Target height was significantly higher in children with normal stature at diagnosis than those with short stature. Growth hormone (GH) deficiency was found and confirmed after 6-12 months of diet in 12 of the 38 patients (32%) with short stature. In the group of the 30 'short' patients who attained final height, target height was attained or improved in 12 patients (40%): in eight of the 16 (50%) responders and in four of the 14 (29%) non-responders; in eight (all responders) out of 22 (36%) without GH deficiency, and in four out of eight (50%) patients with GH deficiency treated with GH (all non-responders).

CONCLUSIONS

In children in whom coeliac disease is diagnosed because of short stature, a gluten-free diet will be successful if at diagnosis there is a delay of bone age and in the first year of diet there is an evident catch-up growth. When this does not occur, i.e. in half of the patients (18 out of 38), it may be because of an associated and transient GH deficiency. In these patients a period of GH replacement therapy as well as a gluten-free diet may improve their final height.

Interventions for growth failure in childhood Crohn's disease

BACKGROUND

Crohn's disease in childhood is a chronic relapsing condition. Fifteen to forty per cent of children with Crohn's disease have growth retardation (Griffiths 1993a). Some treatment modalities including corticosteroids have been implicated in growth failure but it is thought mainly to be secondary to uncontrolled disease activity (Motil 1993; Markowitz 1993). Growth is fundamental to the practice of pediatrics, so by taking growth as the primary outcome measure we address issues important to both patients, their families and pediatricians.

OBJECTIVES

To evaluate the effectiveness of the different modalities available for the treatment of childhood Crohn's disease with regard to the reversal of growth failure and the promotion of normal growth.

SEARCH STRATEGY

Searches were made of the following databases using the Collaborative Review Group Search Strategy: EMBASE (1984-2004), MEDLINE (1966-2004), The Cochrane Central Register of Controlled Trials, The Cochrane Inflammatory Bowel Disease and Functional Bowel Disorders Group Specialized Trials Register and the Science Citation Index. Abstracts from the major gastrointestinal research meetings and references from published articles were also reviewed.

SELECTION CRITERIA

Randomized controlled trials pertaining to children less than 18 years of age with Crohn's disease were selected. Those with growth as an outcome measure were included in the review.

DATA COLLECTION AND ANALYSIS

Data extraction and assessment of the methodological quality of each trial was independently reviewed by two reviewers. Only one good quality randomized controlled trial was included in the review and therefore no statistical analysis was possible.

MAIN RESULTS

Three randomized controlled trials were identified. One was of good methodological quality (Markowitz 2000). This study looked at the use of 6-mercaptopurine (6-MP) as a steroid sparing agent. No difference in linear growth was observed between the intervention and placebo groups, although the total steroid dose received over the 18 month follow up period was reduced in the group receiving 6-MP. The two remaining randomized controlled trials (Sanderson 1987; Thomas 1993a) consider the use of enteral feeding versus corticosteroids for induction of remission, with height velocity standard deviation score at 6 months as an outcome measure. Although of less rigorous methodological quality, the results of these studies are discussed in detail in the review. In both studies height velocity standard deviation scores were significantly increased in the enteral feeding group compared with the corticosteroid group.

AUTHORS' CONCLUSIONS

In addition to these randomized controlled trials, a body of lower quality evidence does exist relevant to two other important interventions; the use of supplemental enteral nutrition (Morin 1980; Belli 1988; Israel 1995) and the judicious use of surgical interventions in pre-pubertal children with refractory disease (Alperstein 1985; Lipson 1990; McLain 1990). Newer treatments, such as infliximab, are now becoming more widely used and may offer advantages in promoting growth. These effects are as yet unstudied. This review highlights the need for large, multi centre studies of the different treatment options in paediatric Crohn's disease and the importance of standardised measurements of growth, such as height velocity standard deviation scores and height standard deviation scores as outcome measures.

Immune activation and nutritional status in adult Crohn's disease patients

BACKGROUND

Recent attention focused on the effect of inflammatory cytokines on intermediary metabolism contributing to the nutritional disturbances observed in acute or chronic inflammatory diseases.

AIMS

To examine the interactions between immune activation and nutritional parameters in adult Crohn's disease patients.

PATIENTS AND METHODS

We analysed anthropometric and biochemical nutritional parameters in 40 Crohn's disease patients and 26 healthy controls, and related them to inflammatory and immune markers.

RESULTS

Weight, body mass index, mid-arm circumference, triceps skinfold thickness, as well as albumin, transthyretin, retinol binding protein, insulin growth factor-I and Vitamin A were significantly decreased in Crohn's disease patients and negatively correlated to disease activity. By contrast, erythrocyte sedimentation rate, fibrinogen, C-reactive protein, alpha1-acylglycoprotein, soluble receptor of interleukin-2, blood neopterin, tumour necrosis factor-alpha and interleukin-1beta concentrations were significantly higher in patients and positively correlated to disease activity. Nutritional parameters and acute phase reactants were linked to tumour necrosis factor-alpha and interleukin-1beta concentrations, and markers of nutritional status were negatively correlated to positive acute phase reactants.

CONCLUSIONS

In Crohn's disease, inflammatory cytokines appear partly responsible for decreased nutritional status. Thus, nutritional intervention to correct nutritional (in particular protein) depletion, and/or therapeutic intervention reducing inflammation and therefore restoring adequate nutritional proteins synthesis, appears a major therapeutic goal in active Crohn's disease.

Infliximab reverses growth hormone resistance associated with inflammatory bowel disease

BACKGROUND

Increasing evidence shows that inflammation plays a major role in the aetiology of catabolism and wasting observed in inflammatory bowel disease via growth hormone resistance.

AIM

To evaluate the effect of infliximab treatment on the growth hormone/insulin-like growth factor-1 axis.

METHODS

Fourteen adults with active Crohn's disease or ulcerative colitis underwent three infliximab infusions at a dose of 5 mg/kg for induction of remission, plus two maintenance infusions 8 weeks apart. Blood samples were collected for the analysis of serum growth hormone, insulin-like growth factor-1, insulin-like growth factor-binding protein-3 and acid labile subunit.

RESULTS

Serum insulin-like growth factor-1 and insulin-like growth factor-binding protein-3 concentrations, which were significantly lower in inflammatory bowel disease patients before treatment compared with controls (P < 0.01), significantly increased during the induction phase (+58% and +29%, respectively, after the second infusion, P < 0.01), and dropped to baseline levels during maintenance therapy. Both insulin-like growth factor-1 and insulin-like growth factor-binding protein-3 showed significant negative correlations with C-reactive protein (rho = -0.37, P = 0.002; rho = -0.35, P = 0.01, respectively). Growth hormone and acid labile subunit levels were not statistically different between controls and inflammatory bowel disease patients either at baseline or during treatment.

CONCLUSIONS

Infliximab induction treatment reverses growth hormone resistance observed in active inflammatory bowel disease through the suppression of systemic inflammation. The restored growth hormone/insulin-like growth factor-1 axis is impaired again following the prolonged interval between maintenance infusions, possibly because of the subclinical reactivation of the inflammatory process.

Effect of recombinant growth hormone treatment on children with Crohn's disease and short stature: a pilot study

BACKGROUND

Growth failure frequently complicates Crohn's disease in childhood. Abnormalities in the growth hormone (GH)/insulin-like growth factor-1 axis may occur. The effects of administered GH on growth have not been studied previously in a randomized trial.

METHODS

Seven children (6 boys and 1 girl; age, 11.9-16 yr) with Crohn's disease and growth failure were enrolled. In phase 1, patients were randomized to either GH (0.05 mg/kg per day) or placebo; in phase 2, patients who received placebo during the first year received GH for various time periods. Follow-up was every 3 months for up to 2 years.

RESULTS

During placebo treatment (4 patients), mean height-for-age z score (haz) increased 0.23 in the first half year and 0.55 in the second half year. The mean improvement in haz during the first half year of GH treatment (7 patients) was 0.13; during the second half year (5 patients), haz decreased 0.01. Effects of GH varied among patients; 2 patients grew only when nutritional supplementation was added. Observed changes were not statistically significant; however, the number of patients studied was small, and statistical analyses could have been affected by sample size. Serum insulin-like growth factor-1 levels correlated with height velocity. Only 2 patients later reached expected adult height.

CONCLUSIONS

In this pilot study, GH treatment at the dose given did not stimulate growth in children with Crohn's disease and short stature. Whether or not GH plus nutritional therapy would be effective in promoting sustained catch-up growth remains to be determined.

Nutrition support for pediatric patients with inflammatory bowel disease: a clinical report of the North American Society for Pediatric Gastroenterology, Hepatology And Nutrition

Impairment of growth and malnutrition are significant complications of inflammatory bowel disease (IBD) in pediatric patients. Since this topic was last reviewed in these pages (), a number of studies have further explored the epidemiology and pathogenesis of these nutritional complications of IBD in an effort to provide more effective interventions to prevent the long-term consequences of chronic nutrient deficiencies in childhood. In addition, during the past 15 years, the use of selected nutrients and microorganisms (probiotics) as primary or adjunctive therapy for the treatment of IBD has become an emerging area of great interest. The following is a Clinical Report from the Nutrition and Inflammatory Bowel Disease Committees of the North American Society for Pediatric Gastroenterology, Hepatology and Nutrition.

Effects of growth hormone secretion on body composition in patients with Crohn's disease

Crohn's disease is a multisystem disorder characterized by chronic intestinal inflammation. Accumulation of mesenteric fat occurs in patients with Crohn's disease, although the mechanisms underlying site-specific changes in adipose deposition are unclear. To investigate whether there are alterations in site-specific adipose deposition in patients with Crohn's disease and to determine hormonal influences that may underlie such changes, we investigated body composition and serum hormone levels in 20 men with Crohn's disease (mean age, 45 +/- 2 yr) and 20 age-, gender-, and body mass index-matched normal controls (mean age, 43 +/- 3 yr). None of the Crohn's patients was receiving glucocorticoid therapy. Subjects underwent hourly GH sampling for 12 h beginning at 2000 h and fasting serum IGF-I and testosterone measurements. Body composition was assessed by quantitative computed tomography of the abdomen and bioelectrical impedance analysis. In the Crohn's disease and control subjects, mean serum GH levels were 1.07 +/- 0.2 and 1.7 +/- 0.2 ng/ml (P = 0.06), serum IGF-I levels were 162.7 +/- 10.5 and 194.8 +/- 15.7 ng/ml (P = 0.1), and serum testosterone levels were 489 +/- 33 and 514 +/- 38 ng/ml (P = NS), respectively. Percentage body fat was significantly higher in the Crohn's patients (21 +/- 0.8% vs. 17.7 +/- 0.9%, respectively; P = 0.013). Intraabdominal fat (IAF) was significantly higher in the Crohn's subjects vs. controls (115 +/- 11 vs. 69 +/- 7 cm(2), respectively; P = 0.001). The ratio of intraabdominal to total body fat was higher in the Crohn's subjects than in the controls (0.4 +/- 0.1 vs. 0.3 +/- 0.1, respectively; P = 0.025). Subcutaneous fat area was similar in the two groups. IAF was higher in Crohn's patients even when controlling for testosterone and mean serum GH. Mean serum GH contributed independently to the differences in IAF (P = 0.001). The ratio of IAF to total body fat remained higher in the Crohn's subjects when controlling for serum testosterone, but was no longer significant in a model that also included IGF-I and mean serum GH. GH levels contributed independently to the differences in the intraabdominal to total body fat ratio (P = 0.02). In the Crohn's patients, serum GH correlated negatively with intraabdominal and total body fat and the ratio of intraabdominal to total body fat. Crohn's disease is associated with an increase in central fat accumulation, with more IAF and a higher ratio of intraabdominal to total body fat compared with controls. Although serum GH levels were similar in the two groups, GH contributed significantly to the abdominal fat measurements. These data show that GH has an important role in modulating visceral fat distribution in patients with Crohn's disease.

Transition of care between paediatric and adult gastroenterology. Assessment of growth and nutrition

Growth is a dynamic process that is characterized by physiological changes in an individual from infancy into adulthood. Growth should be monitored sequentially and is an important tool in the early detection of chronic disease in children. Growth occurs in three phases: infancy, childhood and puberty (adolescence). The adequacy of nutritional status can be assessed by anthropometric measurements that include height, weight and body composition as well as laboratory evaluations. Individual patients can then be compared to normative or expected values. Impaired growth and nutritional status can be seen in a variety of gastrointestinal disorders and are described in this chapter.

The insulin-like growth factor axis in children with inflammatory bowel disease

BACKGROUND

The insulin-like growth factor (IGF) axis consists of two IGFs and six IGF-binding proteins (IGFBPs) that regulate proliferation and differentiation of many cell types. Malnutrition and inflammation alter the IGF axis. The authors evaluated circulating IGFs and IGFBPs in patients with inflammatory bowel disease (IBD) at the time of presentation and compared them with values obtained during remission.

METHODS

Seventeen newly diagnosed pediatric IBD patients were studied on presentation and during remission. Nutritional status was assessed by body mass index (BMI) and serum protein assay. The Lloyd-Still and Green IBD clinical scoring system was used. IGF-I and IGF-II levels were measured by radioimmunoassay, and IGFBP-3 levels were measured by immunoradiometric assay. IGFBPs were quantified on ligand blots with a PhosphorImager.

RESULTS

Body mass index and IBD clinical scores improved after treatment: 18.7 +/- 3.0 versus 21.3 +/- 3.0 kg/m (P = 0.023) and 74.6 +/- 16.7 versus 93.1 +/- 7.4 (P< 0.001), respectively. Protein changes were insignificant. IGFBP-3 levels increased from time of first evaluation to remission: 3,470 +/- 850 versus 4,700 +/- 473 ng/mL (P< 0.001). The ratio of IGFBP-3 to IGFBP-2 increased from first evaluation to remission: 1.7 +/- 1.9 versus 3.9 +/- 1.9 (P= 0.003). IGF-I and IGF-II levels also increased: 139 +/- 167 versus 223 +/- 118 ng/mL (P= 0.011) and 307 +/- 111 versus 386 +/- 73 ng/mL (P= 0.007), respectively.

CONCLUSIONS

Circulating IGFBP-3 levels were low during active IBD and increased at remission in parallel with the IGF-I levels. The IGFBP-3 to IGFBP-2 ratio was altered in the presence of active disease in a manner that would reduce IGF-I action. This abnormality improved after treatment.

Low free and total insulinlike growth factor I (IGF-I) and IGF binding protein-3 levels in chronic inflammatory bowel disease: partial normalization during prednisolone treatment

OBJECTIVES

Catabolism and growth impairment are well known complications of chronic inflammatory bowel disease (CIBD). This may be caused by disease activity itself and/or the medical treatment, which may lead to changes in the growth hormone and insulinlike growth factor I (IGF-I) axis. Interest has focused on corticosteroids, as they are known to influence the growth hormone/IGF-I axis.

METHODS

The aim of the present study was to examine changes in total and free IGF-I, IGF binding proteins (IGFBPs), and IGFBP-3 protease activity in 10 patients with severe acute activity in colon CIBD before and during high dose prednisolone treatment (1 wk) and 3 months tapering. Eight healthy subjects served as controls.

RESULTS

Total and free IGF-I were significantly reduced by 35% and 53%, respectively, before prednisolone treatment (p < 0.05), and free IGF-I remained reduced even by the end of the study period relative to controls (p < 0.05). IGFBP-3 was reduced by 16% before (p < 0.05), with normalization during prednisolone treatment and tapering relative to controls. There was no evidence of increase in IGFBP-3 protease activity. IGFBP-1 was increased before and tended also to be increased during prednisolone treatment and tapering.

CONCLUSIONS

Marked changes in serum total and free IGF-I and IGFBPs were demonstrated in patients with severe exacerbation of CIBD without complete normalization during high dose prednisolone treatment and tapering. These changes may partly be involved in the catabolism of active CIBD patients.

Clinical aspects and pathophysiology of inflammatory bowel disease

The chronic inflammatory bowel diseases (IBD), Crohn's disease and ulcerative colitis, are recognized as important causes of gastrointestinal disease in children and adults. In this review we delineate the clinical manifestations and diagnostic features of IBD. In addition, we summarize important recent advances in our understanding of the immune mediators of intestinal inflammation. This information has led to new therapeutic approaches in IBD. Further, we discuss the considerable data that point to the significance of genetic factors in the development of IBD and the genetic loci which have been implicated through genome-wide searches. The commensal bacterial flora also appears to be a critical element, particularly in regards to Crohn's disease, although the precise role of the bacteria in the disease manifestations remains unclear. Current investigations promise to yield fresh insights in these areas.

Prostatic fluid-free insulin-like growth factor-1 in relation to prostate cancer

OBJECTIVES

To establish the feasibility of measuring free insulin-like growth factor-1 (IGF-1) in prostatic fluid and to determine if there is a difference in free IGF-1 levels in the prostatic fluid of patients with prostatic adenocarcinoma and in normal men.

PATIENTS AND METHODS

Prostatic fluid samples were collected from men with histologically confirmed prostate cancer and from control subjects with no malignancy. Prostatic fluid and serum free IGF-1 levels were measured in duplicate by radioimmunoassay, and the differences analysed using the Mann-Whitney U-test and Pearson correlation.

RESULTS

Prostatic fluid free IGF-1 concentrations did not differ significantly (P = 0.23) and there was no difference in serum free IGF-1 levels between the groups. While serum PSA level was significantly correlated with age (P < 0.001) the free IGF-1 level of prostatic fluid was not. There was also no correlation between prostatic fluid free IGF-1 and serum PSA levels.

CONCLUSIONS

Free IGF-1 can be detected in prostatic fluid with acceptable sensitivity. However, the free IGF-1 level in prostatic fluid does not help to detect patients with prostate cancer and is not a tumour marker.

Reduced serum insulin-like growth factor-1 (IGF-1) and IGF-binding protein-3 levels in adults with inflammatory bowel disease

In the present study, the changes in circulating IGF-1 and its binding protein IGFBP-3 were determined in adult patients with active inflammatory bowel disease (IBD) in order to assess the effect of this inflammatory condition on the IGF system. IGF-1 and IGFBP-3, as well as interleukin-6 (IL-6) were measured in serum obtained from 22 consecutive newly diagnosed patients (mean age 41.3 years) with active IBD, including 10 patients with Crohn's disease (CD), and 12 with ulcerative colitis (UC). For comparison the same parameters were determined in 30 healthy volunteers matched for age, sex and Body Mass Index (BMI). Serum IGF-1 and IGFBP-3 levels were similar in the two subgroups of patients and the values from all patients were combined for comparison with those from the control group. The mean (+/- SD) serum IGF-1 concentration (178 +/- 91 ng/ml) in the patients with IBD was lower compared with that in the controls (227 +/- 79 ng/ml, P<0.035). Similarly, the mean IGFBP-3 concentration in the patients was lower than in the controls (1.6 +/- 0.6 ng/ml vs 3.2 +/- 0.7 ng/ml respectively, P<0.001), Serum IL-6 levels were higher in the patients compared with the controls (5.5 +/- 4.2 vs 0.65 +/- 0.11 pg/ml, P<0.0001). The reduced IGF-1 and IGFBP-3 levels in patients with active IBD suggest that this systemic inflammatory condition is associated with a degree of acquired GH resistance, possibly induced by inflammatory cytokines.

Ubiquitous transgenic expression of the IL-23 subunit p19 induces multiorgan inflammation, runting, infertility, and premature death

p19, a molecule structurally related to IL-6, G-CSF, and the p35 subunit of IL-12, is a subunit of the recently discovered cytokine IL-23. Here we show that expression of p19 in multiple tissues of transgenic mice induced a striking phenotype characterized by runting, systemic inflammation, infertility, and death before 3 mo of age. Founder animals had infiltrates of lymphocytes and macrophages in skin, lung, liver, pancreas, and the digestive tract and were anemic. The serum concentrations of the proinflammatory cytokines TNF-alpha and IL-1 were elevated, and the number of circulating neutrophils was increased. In addition, ubiquitous expression of p19 resulted in constitutive expression of acute phase proteins in the liver. Surprisingly, liver-specific expression of p19 failed to reproduce any of these abnormalities, suggesting specific requirements for production of biologically active p19. Bone marrow transfer experiments showed that expression of p19 by hemopoietic cells alone recapitulated the phenotype induced by its widespread expression, pointing to hemopoietic cells as the source of biologically active p19. These findings indicate that p19 shares biological properties with IL-6, IL-12, and G-CSF and that cell-specific expression is required for its biological activity.

Enhanced survival and mucosal repair after dextran sodium sulfate-induced colitis in transgenic mice that overexpress growth hormone

BACKGROUND & AIMS

Growth hormone (GH) is used as therapy for inflammatory bowel disease (IBD), but the specific effects on intestine are unknown. Transgenic mice overexpressing GH (MT1-bGH-TG) were used to test whether increased plasma GH levels alter inflammation or crypt damage during dextran sodium sulfate (DSS)-induced colitis.

METHODS

MT1-bGH-TG and wild-type (WT) littermates were given 3% DSS for 5 days followed by up to 10 days of recovery. Colitis and epithelial cell proliferation were evaluated histologically. Plasma insulin-like growth factor (IGF)-I and colonic IGF-I, interleukin (IL)-1beta, and intestinal trefoil factor (ITF) messenger RNAs (mRNAs) were measured.

RESULTS

DSS induced similar disease onset in MT1-bGH-TG and WT. More MT1-bGH-TG survived than WT. By recovery day 7, MT1-bGH-TG had less inflammation and crypt damage, elevated plasma IGF-I, and increased colonic ITF expression relative to WT. Colonic IL-1beta was elevated in DSS-treated MT1-bGH-TG and WT, but IL-1beta mRNA abundance correlated with disease only in WT. MT1-bGH-TG showed earlier increases in epithelial cell proliferation than WT during recovery but only WT showed atypical repair.

CONCLUSIONS

GH does not alter susceptibility to acute DSS-induced colitis but enhances survival, remission of inflammation, and mucosal repair during recovery. GH therapy may be beneficial during active IBD by improving mucosal repair.

[Protein requirements in children during states of stress. Committee on Nutrition of the French Society of Pediatrics]

Acute and chronic stress conditions affecting critically ill children are characterized by severe protein breakdown and growth failure. This paper describes the disorders of protein metabolism, and gives recommendations for protein and energy intakes during stress conditions in children.

The circulating insulin-like growth factor system in children with coeliac disease: an additional marker for disease activity

BACKGROUND

Chronic undernutrition resulting from coeliac disease (CD) could be associated with changes in the circulating insulin-like growth factor (IGF) system, which may participate in the pathogenesis of growth retardation occurring in these patients.

METHODS

We performed a cross-sectional study in CD subjects attempting to (1) document the pattern of serum IGF-I and IGF binding protein (IGFBP) 1 and 3 at diagnosis and (2) assess the response of circulating IGF system to dietary treatments, in comparison with the response of clinical and laboratory findings utilized for the diagnosis of CD. Thirty-two prepubertal CD children were divided into three groups based on the dietetic treatment: at diagnosis (D, n=18); on gluten-free diet for at least 6 months (GFD, n=7); and on gluten challenge for at least 3 months (CH, n=7). Six postpubertal CD patients were also studied at diagnosis.

RESULTS

In prepubertal children IGF-I levels were significantly reduced (by 29%) in D vs sex- and age-matched normal control (NC) subjects, with reductions being more pronounced before 3 years of age. Likewise, serum IGFBP-3 concentrations were decreased by 22%, whereas circulating IGFBP-1 levels were increased by 60%, compared with NC, with more marked IGFBP changes in older children. Similar alterations were observed in postpubertal patients. Changes in the circulating IGF system disappeared in GFD subjects and reappeared in CH children, as positivity of disease-specific antibodies. Body mass index (BMI) also improved in GFD subjects, but did not decrease in CH children. Changes in IGF-I and IGFBPs did not correlate with each other. Levels of IGF-I, but not of IGFBPs, maintained the relation with age and correlated significantly with BMI and positivity of antibodies.

CONCLUSIONS

These results demonstrate that CD patients show significant changes in serum IGF-I, in younger children, and IGFBPs (particularly IGFBP-1), in older children and adolescents, correlating with clinical course and response to dietary treatments. The alteration in the circulating IGF system could be implicated in the pathogenesis of growth retardation occurring in CD and may provide an additional tool in monitoring of the disease.