Cecilia Camacho-Hübner

Anti-inflammatory and growth-stimulating effects precede nutritional restitution during enteral feeding in Crohn disease.

Objectives Exclusive enteral feeding reduces inflammation and improves well being, nutrition and growth in children with active Crohn disease. Whether improved growth and increases in growth-related proteins are a consequence of improved nutrition or a reduced inflammation is not known. This study was undertaken to test the hypothesis that changes in growth-related proteins are related to decreased inflammation, rather than improvement in nutritional status. Methods Twelve children with active Crohn disease treated for 6-weeks with exclusive enteral feeding were studied at days 0, 3, 7, 14, 21, 28, and 56. The Paediatric Crohns Disease Activity Index (PCDAI), weight, triceps skinfold thickness, and midupper arm circumference were recorded. C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), interleukin-6 (IL-6), insulin-like growth factor (IGF-I), IGF-binding protein (IGFBP-3), and leptin were measured at each visit. Wilcoxon matched-pairs signed-rank test was used to compare day 0 with follow-up data. Results Significant improvements (P < 0.05) occurred by day 3 in inflammatory parameters (ESR, IL-6) and by day 7 in PCDAI, CRP, and IGF-I. These changes preceded any significant changes in nutritional parameters (weight-for-age Z score and midupper arm circumference day 14, triceps skinfold thickness day 21). Conclusions Early increases in IGF-I during treatment of Crohn disease are attributable to the anti-inflammatory effect of the enteral feed rather than nutritional restitution.

Evidence for a Continuum of Genetic, Phenotypic, and Biochemical Abnormalities in Children with Growth Hormone Insensitivity

GH insensitivity (GHI) presents in childhood as growth failure and in its severe form is associated with dysmorphic and metabolic abnormalities. GHI may be caused by genetic defects in the GH-IGF-I axis or by acquired states such as chronic illness. This article discusses the former category. The field of GHI due to mutations affecting GH action has evolved considerably since the original description of the extreme phenotype related to homozygous GH receptor (GHR) mutations over 40 yr ago. A continuum of genetic, phenotypic, and biochemical abnormalities can be defined associated with clinically relevant defects in linear growth. The role and mechanisms of the GH-IGF-I axis in normal human growth is discussed, followed by descriptions of mutations in GHR, STAT5B, PTPN11, IGF1, IGFALS, IGF1R, and GH1 defects causing bioinactive GH or anti-GH antibodies. These defects are associated with a range of genetic, clinical, and hormonal characteristics. Genetic abnormalities causing growth failure that is less severe than the extreme phenotype are emphasized, together with an analysis of height and serum IGF-I across the spectrum of different types of GHR defects. An overall view of genotype and phenotype relationships is presented, together with an updated approach to the assessment of the patient with GHI, focusing on investigation of the GH-IGF-I axis and relevant molecular studies contributing to this diagnosis.

Responsiveness of IGF‐I and IGFBP‐3 to therapeutic intervention in children and adolescents with Crohn's disease

Abnormal linear growth is common in childhood and adolescent Crohns disease. We have studied the concentrations of the inflammatory marker CRP and of serum IGF‐I and IGFBP‐3 in patients with active Crohns disease and have assessed the changes in these parameters during therapeutic intervention with enteral nutrition or intestinal resection.

Human Acid-Labile Subunit Deficiency: Clinical, Endocrine and Metabolic Consequences

The majority of insulin-like growth factor (IGF)-I and IGF-II circulate in the serum as a complex with the insulin-like growth factor binding protein (IGFBP)-3 or IGFBP-5, and an acid-labile subunit (ALS). The function of ALS is to prolong the half-life of the IGF-I-IGFBP-3/IGFBP-5 binary complexes. Fourteen different mutations of the human IGFALS gene have been identified in 17 patients, suggesting that ALS deficiency may be prevalent in a subset of patients with extraordinarily low serum levels of IGF-I and IGFBP-3 that remain abnormally low upon growth hormone stimulation. Postnatal growth was clearly affected. Commonly, the height standard deviation score before puberty was between –2 and –3, and approximately 1.4 SD shorter than the midparental height SDS. Pubertal delay was found in 50% of the patients. Circulating IGF-II, IGFBP-1, -2 and -3 levels were reduced, with the greatest reduction observed for IGFBP-3. Insulin insensitivity was a common finding, and some patients presented low bone mineral density. Human ALS deficiency represents a unique condition in which the lack of ALS proteins results in the disruption of the entire IGF circulating system. Despite a profound circulating IGF-I deficiency, there is only a mild impact on postnatal growth. The preserved expression of locally produced IGF-I might be responsible for the preservation of linear growth near normal limits.

Relationships between serum IGF-1, IGFBP-2, interleukin-1beta and interleukin-6 in inflammatory bowel disease.

Aims: To study the relationships between serum IGF-1, IGFBP-3 and IGFBP-2 and interleukin (IL)-1β and IL-6 in inflammatory bowel disease (IBD). Methods: Thirty-seven patients (18 males, 19 females, aged 8.8–26.1 years) with IBD (Crohn’s disease, CD, n = 17, and ulcerative colitis, UC, n = 20) were studied. Patients were in relapse or remission according to established criteria. Serum IGF-1, IGFBP-3, IGFBP-2, IL-1β and IL-6 levels were determined in patients and 15 healthy controls (aged 8.2–19.0 years). Results: IGF-1 levels were lower in patients with CD in relapse compared with controls (p < 0.05). IGFBP-2 levels were higher in CD in relapse compared with other groups (all p < 0.05). In CD and UC patients (n = 37), IGF-1 levels were inversely correlated with the erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP). IGFBP-2 levels correlated positively with ESR and IL-1β. IL-6 levels correlated positively with ESR and CRP. IL-1β levels were elevated in CD in relapse compared to controls (p < 0.05) and were higher in UC in relapse than in other groups (all p < 0.05). In combined CD/UC patients in relapse (n = 20), IL-1β levels were higher (p < 0.05) in patients with recto-sigmoiditis (n = 5) than in other patients. Conclusions: IGF-1, IGFBP-2 levels were related to IL levels, disease activity and anatomical distribution, consistent with active inflammation modifying the IGF-IGFBP system, possibly relevant to disturbance of growth.

Endocrine assessment, molecular characterization and treatment of growth hormone insensitivity disorders.

Advances in the diagnosis and treatment of growth hormone insensitivity disorders have occurred in the past 15 years. We discuss the current status of endocrine and molecular evaluation, focusing on the pediatric age range. All the identified mutations of the growth hormone receptor are included. Treatment with recombinant human insulin-like growth factor (rhIGF) 1 in classical cases is summarized and new targets for treatment are discussed, together with therapy using the complex formed between rhIGF1 and rhIGF-binding protein 3.

The differential regulation of the circulating levels of the insulin-like growth factors and their binding proteins (IGFBP) 1, 2 and 3 after elective abdominal surgery

OBJECTIVES Patients undergoing abdominal surgery often suffer from morbidity associated with increased protein catabolism. Therapeutic recombinant human insulin‐like growth factor (rhIGF)‐I has been proposed as a means of reversing this process. As IGFBPs modulate the bioavailability of the IGFs, we have studied the changes in the circulating levels of these peptides during surgery.

Growth in Crohn's disease

Savage MO, Beattie RM, Camacho‐Hubner C, Walker‐Smith JA, Sanderson IR. Growth in Crohns disease. Acta Paediatr 1999; Suppl 428:89‐92. Stockholm. ISSN 0803‐5326

Normal growth hormone secretion in growth hormone insufficient children retested after completion of linear growth

OBJECTIVE The recognition of the syndrome of adult GH deficiency suggests that young GH deficient adults, deprived of GH replacement at completion of linear growth, may suffer effects of GH deficiency. We assessed GH reserve in young adults previously diagnosed as having idiopathic GH insufficiency, who were treated with hGH replacement (14 IU/m2/week) in childhood.

Standard and low‐dose IGF‐I generation tests and spontaneous growth hormone secretion in children with idiopathic short stature

objective  Abnormalities in the GH–IGF‐I axis, consistent with GH insensitivity (GHI), have been reported in some patients with idiopathic short stature (ISS). The standard IGF‐I generation test (IGFGT) has not demonstrated mild GHI in subjects with ISS. The aim of this study was to investigate the GH–IGF‐I axis in ISS by performing standard and novel low‐dose IGFGTs together with determination of spontaneous GH secretion.