Serum IGF1 and linear growth in children with congenital leptin deficiency before and after leptin substitution.

BACKGROUND: Evidence from in vitro and rodent studies suggests that leptin, a key signal of long-term energy reserves, promotes IGF1 synthesis and linear growth. This effect of leptin has not been fully investigated in humans. The aim of our study was to investigate the effect of leptin substitution on growth factors and linear growth in children with congenital leptin deficiency (CLD). METHODS: In this cohort study we included eight pediatric patients (six males), age 0.9-14.8 years, who were diagnosed with CLD and received leptin substitution at our University Medical Center. We calculated standard deviation scores (SDS) for serum levels of IGF1 and IGFBP3, IGF1/IGFBP3 molar ratio, and height at baseline (T0) and 12 months (T12) after the initiation of substitution with metreleptin. RESULTS: All patients had severe obesity (BMI-SDS mean ± SD: 4.14 ± 1.51) at T0 and significant BMI-SDS reduction to 2.47 ± 1.05 at T12. At T0, all patients were taller than the mid-parental median, yet had low IGF1 and IGF1/IGFBP3 molar ratios (IGF1-SDS[Formula: see text]T0: -1.58 ± 0.92, IGF1/IGFBP3 molar ratio-SDS[Formula: see text]T0: -1.58 ± 0.88). At T12, IGF1-SDS increased significantly (∆T0-12: 1.63 ± 1.40, p = 0.01), and IGFBP3-SDS and IGF1/IGFBP3 molar ratio-SDS showed a trend toward an increase. In the three children within the childhood growth period (post-infancy, pre-puberty) height-SDS increased (∆height-SDST0-12: 0.57 ± 0.06, p = 0.003) despite substantial weight loss. CONCLUSIONS: These results in CLD patients are contrary to observations in children with idiopathic obesity who typically have above-mean IGF1 levels that decrease with weight loss, and therefore suggest that leptin increases IGF1 levels and promotes linear growth.

Age-related changes in energy metabolism in peripheral mononuclear blood cells (PBMCs) and the brains of cognitively healthy seniors.

Mitochondrial dysfunction is a hallmark of cellular senescence and many age-related neurodegenerative diseases. We therefore investigated the relationship between mitochondrial function in peripheral blood cells and cerebral energy metabolites in young and older sex-matched, physically and mentally healthy volunteers. Cross-sectional observational study involving 65 young (26.0 ± 0.49 years) and 65 older (71.7 ± 0.71 years) women and men recruited. Cognitive health was evaluated using established psychometric methods (MMSE, CERAD). Blood samples were collected and analyzed, and fresh peripheral blood mononuclear cells (PBMCs) were isolated. Mitochondrial respiratory complex activity was measured using a Clarke electrode. Adenosine triphosphate (ATP) and citrate synthase activity (CS) were determined by bioluminescence and photometrically. N-aspartyl-aspartate (tNAA), ATP, creatine (Cr), and phosphocreatine (PCr) were quantified in brains using 1H- and 31P-magnetic resonance spectroscopic imaging (MRSI). Levels of insulin-like growth factor 1 (IGF-1) were determined using a radio-immune assay (RIA). Complex IV activity (CIV) (- 15%) and ATP levels (- 11%) were reduced in PBMCs isolated from older participants. Serum levels of IGF-1 were significantly reduced (- 34%) in older participants. Genes involved in mitochondrial activity, antioxidant mechanisms, and autophagy were unaffected by age. tNAA levels were reduced (- 5%), Cr (+ 11%), and PCr (+ 14%) levels were increased, and ATP levels were unchanged in the brains of older participants. Markers of energy metabolism in blood cells did not significantly correlate with energy metabolites in the brain. Age-related bioenergetic changes were detected in peripheral blood cells and the brains of healthy older people. However, mitochondrial function in peripheral blood cells does not reflect energy related metabolites in the brain. While ATP levels in PBMCs may be be a valid marker for age-related mitochondrial dysfunction in humans, cerebral ATP remained constant.

Leptin plasma concentrations increase during antidepressant treatment with amitriptyline and mirtazapine, but not paroxetine and venlafaxine: leptin resistance mediated by antihistaminergic activity?

Treatment with several psychopharmacological agents has been associated with increased leptin plasma concentrations. We measured leptin plasma concentrations in 76 adult depressed patients after a 6-day washout phase and again after 35 days of treatment with amitriptyline or paroxetine, as well as in 73 depressed patients after 28 days of treatment with either mirtazapine or venlafaxine. Leptin plasma concentrations increased during treatment with amitriptyline and mirtazapine, even after controlling for increased body mass index and irrespective of response to treatment [14.5 (13.8) vs 20.3 (18.7) ng/mL, and 12.2 (15.8) vs 14.4 (16.5) ng/mL in the 2 cohorts, respectively]. In contrast, paroxetine and venlafaxine treatment was not associated with changes in leptin plasma concentrations [14.8 (12.0) vs 13.6 (10.6); 15.9 (17.3) vs 13.5 (14.6) ng/mL] nor with weight gain. We conclude that treatment with amitriptyline or mirtazapine is associated with an increase in leptin secretion beyond change in weight. Thus, high leptin levels apparently are ineffective in the control of weight gain, indicating leptin resistance. Leptin resistance may be mediated by an antihistaminergic effect on hypothalamic nuclei integrating signals relevant for energy balance.

A Novel Method for Adult Height Prediction in Children With Idiopathic Short Stature Derived From a German-Dutch Cohort.

Context: Prediction of adult height (AH) is important in clinical management of short children. The conventional methods of Bayley-Pinneau (BP) or Roche-Wainer-Thissen (RWT) have limitations. Objective: We aimed to develop a set of algorithms for AH prediction in patients with idiopathic short stature (ISS) which are specific for combinations of predicting variables. Methods: Demographic and auxologic data were collected in childhood (1980s) and at AH (1990s). Data were collected by Dutch and German referral centers for pediatric endocrinology. A total of 292 subjects with ISS (219 male, 73 female) were enrolled. The population was randomly split into modeling (n = 235) and validation (n = 57) cohorts. Linear multi-regression analysis was performed with predicted AH (PAH) as response variable and combinations of chronological age (CA), baseline height, parental heights, relative bone age (BA/CA), birth weight, and sex as exploratory variables. Results: Ten models including different exploratory variables were selected with adjusted R² ranging from 0.84 to 0.78 and prediction errors from 3.16 to 3.68 cm. Applied to the validation cohort, mean residuals (PAH minus observed AH) ranged from -0.29 to -0.82 cm, while the conventional methods showed some overprediction (BP: +0.53 cm; RWT: +1.33 cm; projected AH: +3.81 cm). There was no significant trend of residuals with PAH or any exploratory variables, in contrast to BP and projected AH. Conclusion: This set of 10 multi-regression algorithms, developed specifically for children with ISS, provides a flexible tool for AH prediction with better accuracy than the conventional methods.

Childhood trauma and insulin-like growth factors in amniotic fluid: An exploratory analysis of 79 women.

BACKGROUND: Perinatal stress has adverse effects on fetal outcome, yet the effect of early maternal trauma on fetal outcome has scarcely been studied. We investigated effects of maternal childhood trauma and current environment on important regulators of prenatal growth, fetal insulin-like growth factor (IGF)-1 and IGF-2 in amniotic fluid and assessed the impact of IGFs on newborn anthropometrics. METHODS: 79 pregnant women in their second trimester who underwent amniocentesis (15.9 ± 0.9 weeks of gestational age) and their newborns at birth were analyzed. Maternal childhood trauma was assessed using the childhood trauma questionnaire (CTQ) and current environment was operationalized by assessing maternal psychosocial, physical health and endocrine measurements in amniotic fluid. RESULTS: In this exploratory analysis of 79 pregnant women, maternal childhood trauma, defined as reporting at least low scores on any of the CTQ subscales, negatively correlated with fetal IGF-1 (Mln = 3.48 vs. 2.98; p = 0.012) and IGF-2 (Mdnln = 4.99 vs. 4.70; p = 0.002). Trauma severity, defined as the overall trauma score, negatively correlated with fetal IGF-2 (r = -0.24; p = 0.037). From trauma subscales, maternal sexual abuse correlated with fetal IGF-1 (r = -0.32; p = 0.006) and IGF-2 (r = -0.39; p = 0.001). Maternal BMI negatively correlated with fetal IGF-1 (r = -0.26; p = 0.023) and IGF-2 (r = -0.29; p = 0.011). Newborn anthropometrics were operationalized by length, weight, sex, gestational age, length/gestational age and weight/gestational age at birth. Fetal weight at birth associated with a trend with fetal IGF-1 when controlling for BMI. Maternal hypothalamus-pituitary-adrenal axis activity and maternal exercise did not contribute significantly to predicting fetal IGFs. Maternal childhood trauma (ß = -0.27; p = 0.011) and BMI (ß = -0.24; p = 0.026) remained significantly associated with fetal IGF-1. Maternal childhood trauma (ß = -0.32; p = 0.003), maternal BMI (ß = -0.30; p = 0.005) and maternal sexual abuse (ß = -0.22; p = 0.049) remained significantly associated with fetal IGF-2 and with a trend with fetal IGF-1 (ß = -0.21; p = 0.076) when excluding women with gestational diabetes. CONCLUSION: Maternal childhood trauma and BMI associate negatively with fetal IGF-1 and IGF-2 in amniotic fluid. Controlling for maternal BMI, fetal weight at birth remains associated with a trend with fetal IGF-1. The presented data suggests that childhood trauma can affect endocrine measurements of the developing next generation, providing a mechanism by which adverse maternal life events are transmitted to the next generation.

Corroboration of Height Velocity Prediction Markers for rhGH With an Oral GH Secretagogue Treatment in Children With GHD.

CONTEXT: Recombinant human growth hormone (rhGH) is approved for treatment of pediatric growth hormone deficiency (GHD), with greatest growth responses observed in those with severe GHD. Orally administered GH secretagogues (GHS) may be useful treatment in patients with moderate GHD. Distinguishing children with severe vs moderate GHD could identify children who would be better treated with rhGH or GHS. OBJECTIVES: Evaluate baseline insulin-like growth factor-I (IGF-I) and stimulated peak GH response as predictors of 12-month height velocity (HV) in children with GHD. DESIGN: Data on children with GHD were analyzed in a legacy data base (GeNeSIS data). PARTICIPANTS: 514 naïve to rhGH-treatment, prepubertal children with idiopathic isolated GHD for whom stimulated GH, baseline serum IGF-I, and first-year HV during rhGH treatment data are available. OUTCOME MEASURES: Children with severe or moderate GHD were categorized based on GH and IGF-I data and evaluated based on baseline auxologic and hormone profiles and first-year growth response to rhGH. RESULTS: Cohorts of severe and moderate GHD were 81/514 (15.8%) and 433/514 (84.2%). Cohorts differed significantly with regard to indicators of GHD [eg, baseline height SD score (SDS), height SDS minus target height SDS, HV, HV SDS, and change in height SDS during rhGH treatment]. Multiple regression analysis showed IGF-I and stimulated GH were significant predictors of HV independent of other known variables. Expected first-year HV in moderate GHD was 8.3 cm/y. CONCLUSIONS: The combination of peak GH to GH stimulation testing and baseline IGF-I concentration are predictive enrichment markers for annualized HV responses to rhGH therapy.

Development of a Predictive Enrichment Marker for the Oral GH Secretagogue LUM-201 in Pediatric Growth Hormone Deficiency.

CONTEXT: We hypothesize, based on the degree of residual hypothalamic-pituitary function, that some, but not all, children with growth hormone deficiency (GHD) may have beneficial growth responses to the orally administered growth hormone (GH) secretagogue LUM-201. OBJECTIVE: To determine if pretreatment testing can identify predictive enrichment markers (PEM) for subjects with adequate residual function who are responsive to LUM-201. METHODS: We performed an analysis of a completed, randomized, placebo-controlled trial of LUM-201, a GH secretagogue receptor agonist, in which all randomized subjects had pretreatment testing. This international multicenter study conducted in pediatric endocrinology clinics included 68 naïve-to-treatment, prepubertal children with established diagnoses of GHD. Outcome measures included the sensitivity, specificity, and predictive accuracy of potential markers to predict 6-month growth responses to oral LUM-201 and daily rhGH. RESULTS: Two PEM were identified for use in defining PEM-positive status: (1) baseline insulin-like growth factor I (IGF-I) concentration >30 ng/mL and (2) peak GH response of ≥5 ng/mL upon administration of single-dose LUM-201. PEM-positive status enriches a population for better growth responses to LUM-201. PEM-negative status enriches a population for better growth responses to rhGH. CONCLUSION: Combined, the peak GH response to single-dose LUM-201 and the baseline IGF-I concentration are effective PEMs for 6-month growth responses to LUM-201 and rhGH in prepubertal children with GHD.

The IGF/IGFBP system in relation to macroscopic bone architecture in pediatric renal transplant patients.

The post-transplant bone disease of the peripheral skeleton in pediatric renal transplant recipients is characterized by an inadequately thin bone cortex in relation to muscular force. A major hormonal modulator of periosteal growth is the insulin-like growth factor (IGF)/IGF binding protein (IGFBP) system. We therefore hypothesized that the reduced cortical thickness in these patients may be due to functional IGF deficiency. To test this hypothesis, we investigated 55 patients (mean estimated glomerular filtration rate 86.3 +/- 30.0 ml/min/1.73 m(2)) in a cross-sectional study. Parameters of macroscopic bone architecture and forearm muscle size were analyzed by peripheral quantitative computed tomography (pQCT), and serum IGF/IGFBP system components were measured by specific radioimmunoassays. The mean (+/- standard deviation) standardized serum IGF-I (0.20 +/- 1.16 score) level was normal, while the mean IGF-II (1.16 +/- 0.11 score) level was significantly elevated. Serum IGFBP-1 and IGFBP-2 levels were not altered, whereas the IGFBP-3 (1.34 +/- 0.15 score) level was significantly increased. The serum IGFBP-4 level was slightly elevated (by 11%), the IGFBP-6 level was markedly (2.3-fold) elevated, while the IGFBP-5 level was comparable to that of the control. The respective age-adjusted cortical thickness at both the proximal (r = 0.407, P < 0.005) and distal (r = 0.383, P < 0.01) forearm was positively correlated with the standardized serum IGF-I level. In conclusion, the serum IGF/IGFBP system in pediatric renal transplant recipients is characterized by an increase in the levels of the inhibitory IGFBPs, IGFBP-3, -4 and -6, resulting in a functional IGF deficiency. The positive correlation of IGF-I with cortical thickness underlines the importance of this hormonal system in the modeling of bone, particularly periosteal growth.

Changing patterns of the adult growth hormone deficiency diagnosis documented in a decade-long global surveillance database.

BACKGROUND: GH therapy in adult patients with GH deficiency (GHD) was approved over 10 yr ago, and the indication has subsequently gained broad acceptance. The HypoCCS surveillance database is a suitable means to examine the evolution of diagnostic patterns since 1996. METHODS: Baseline demographics, reported cause of GHD, and diagnostic tests were available from 5893 GH-treated patients. Trends for change over time in diagnosis, GH stimulation test data, and IGF-I measurements were analyzed at 2-yr intervals by linear regression models, with entry year as the predictive variable. RESULTS: Over the decade, there was a decrease in patients enrolled with diagnoses of pituitary adenoma (50.2 to 38.6%; P < 0.001), craniopharyngioma (13.3 to 8.4%; P = 0.005) and pituitary hemorrhage (5.8 to 2.8%; P = 0.001); increases in idiopathic GHD (13.9 to 19.3%; P < 0.001), less common diagnoses (7.4 to 15.8%; P < 0.001), and undefined/unknown diagnoses (1.3 to 8.6%; P < 0.001) were observed. Use of arginine, clonidine, and L-dopa tests declined, whereas use of the GHRH-arginine test increased. Median values for peak GH from all tests except GHRH-arginine and for IGF-I SD scores increased significantly (P < 0.001). Over the decade (1996--2005), idiopathic GHD was reported for 16.7% of patients, and more than half of these had adult onset GHD. In the idiopathic adult onset group, 40.2% had isolated GHD; 18.3 and 4.4% had a stimulation test GH peak of at least 3.0 and 5.0 microg/liter, respectively. CONCLUSIONS: Significant shifts in diagnostic patterns have occurred since approval of the adult GHD indication, with a trend to less severe forms of GHD.

Height gains in response to growth hormone treatment to final height are similar in patients with SHOX deficiency and Turner syndrome.

BACKGROUND: Patients with mutations or deletions of the Short Stature Homeobox-containing(SHOX) gene have variable degrees of growth impairment, with or without mesomelic skeletal dysplasia. If untreated, short patients with SHOX deficiency remain short in adulthood. Growth hormone (GH) treatment improves short-term linear growth; however, there are no data on GH treatment effects on final height. PATIENTS: In a retrospective study, we assessed the relative effects of GH on final height gain in patients with SHOX deficiency (n = 14; 12 females) and Turner syndrome (TS) (n = 158). Patients were included if they fulfilled the following criteria: genetically-confirmed SHOX deficiency or TS, baseline height SDS <1.5, GH treatment started at Tanner stage < or =2, duration of GH treatment >2 years, and final height attained. RESULTS: Both groups of patients were short at baseline (height SDS [mean +/- SD]: SHOX deficiency, -3.3 +/- 0.9; TS, -2.9 +/- 0.8). Height SDS gain from baseline to final height was significant for each patient group (SHOX deficiency, 1.1 +/- 0.7; TS, 1.2 +/- 0.8; p < 0.001); however, it was not significantly different between groups (p = 0.708). CONCLUSIONS: Patients with SHOX deficiency receive similar final height benefit from GH treatment to those with TS.

Genetic Polymorphisms Associated with Idiopathic Short Stature and First-Year Response to Growth Hormone Treatment.

BACKGROUND/AIMS: The term idiopathic short stature (ISS) describes short stature of unknown, but likely polygenic, etiology. This study aimed to identify genetic polymorphisms associated with the ISS phenotype, and with growth response to supplemental GH. METHODS: Using a case-control analysis we compared the prevalence of "tall" versus "short" alleles at 52 polymorphic loci (17 in growth-related candidate genes, 35 identified in prior genome-wide association studies of adult height) in 94 children with ISS followed in the Genetics and Neuroendocrinology of Short Stature International Study, versus 143 controls from the Fels Longitudinal Study. RESULTS: Four variants were nominally associated with ISS using a genotypic model, confirmed by a simultaneous confident inference approach: compared with controls children with ISS had lower odds of "tall" alleles (odds ratio, 95% CI) for GHR (0.52, 0.29-0.96); rs2234693/ESR1 (0.50, 0.25-0.98); rs967417/BMP2 (0.39, 0.17-0.93), and rs4743034/ZNF462 (0.40, 0.18-0.89). Children with ISS also had lower odds of the "tall" allele (A) at the IGFBP3 -202 promoter polymorphism (rs2855744; 0.40, 0.20-0.80) in the simultaneous confident inference analysis. A significant association with 1st-year height SD score increase during GH treatment was observed with rs11205277, located near 4 known genes: MTMR11, SV2A, HIST2H2AA3, and SF3B4; the latter, in which heterozygous mutations occur in Nager acrofacial dysostosis, appears the most relevant gene. CONCLUSIONS: In children with ISS we identified associations with "short" alleles at a number of height-related loci. In addition, a polymorphic variant located near SF3B4 was associated with the GH treatment response in our cohort. The findings in our small study warrant further investigation.

Height Gain and Safety Outcomes in Growth Hormone-Treated Children with Idiopathic Short Stature: Experience from a Prospective Observational Study.

BACKGROUND/OBJECTIVES: Growth hormone (GH) treatment of idiopathic short stature (ISS) received US Food and Drug Administration approval in 2003. We assessed height gain and safety in 2,450 children with ISS treated with GH in US clinical practice. METHODS: Short-term height gain, near-adult height (NAH), and safety outcomes were investigated using Genetics and Neuroendocrinology of Short Stature International Study data. RESULTS: Compared to children with isolated idiopathic GH deficiency (IGHD), those with ISS were shorter at baseline but had similar age and GH dose. Mean ± SD height SD score (SDS) increase was similar for ISS and IGHD, with 0.6 ± 0.3 (first), 0.4 ± 0.3 (second), 0.3 ± 0.3 (third), and 0.1 ± 0.3 (fourth year) for ISS. Girls with ISS (27% of subjects) were younger and shorter than boys but had similar height gain over time. At NAH in the ISS group (n = 467), mean ± SD age, GH duration, and height SDS were 17.3 ± 2.3 years, 4.6 ± 2.7 years, and -1.2 ± 0.9, respectively. Height gain from baseline was 1.1 ± 1.0 SDS and was greater for boys than girls (1.2 ± 1.0 vs. 0.9 ± 0.9), but boys were treated longer (5.1 ± 2.8 vs. 3.6 ± 2.5 years). Adverse events were reported for 24% with ISS versus 20% with IGHD - most were common childhood conditions or previously reported in GH-treated patients. CONCLUSIONS: GH-treated children with ISS achieved substantial height gain, similar to patients with IGHD. Fewer GH-treated girls were enrolled than boys, but with similar height SDS gain over time. No ISS-specific safety issues were identified. Thus, GH treatment of ISS appears to have a safety/effectiveness profile similar to that of IGHD.

Safety Outcomes During Pediatric GH Therapy: Final Results From the Prospective GeNeSIS Observational Program.

Context: Safety concerns have been raised regarding premature mortality, diabetes, neoplasia, and cerebrovascular disease in association with GH therapy. Objective: To assess incidence of key safety outcomes. Design: Prospective, multinational, observational study (1999 to 2015). Setting: A total of 22,311 GH-treated children from 827 investigative sites in 30 countries. Patients: Children with growth disorders. Interventions: GH treatment. Main outcome measures: Standardized mortality ratio (SMR) and standardized incidence ratio (SIR) with 95% CIs for mortality, diabetes, and primary cancer using general population registries. Results: Predominant short stature diagnoses were GH deficiency (63%), idiopathic short stature (13%), and Turner syndrome (8%), with mean ± SD follow-up of 4.2 ± 3.2 years (∼92,000 person-years [PY]). Forty-two deaths occurred in patients with follow-up, with an SMR (95% CI) of 0.61 (0.44, 0.82); the SMR was elevated for patients with cancer-related organic GH deficiency [5.87 (3.21, 9.85)]. Based on 18 cases, type 2 diabetes mellitus (T2DM) risk was elevated [SIR: 3.77 (2.24, 5.96)], but 72% had risk factors. In patients without cancer history, 14 primary cancers were observed [SIR: 0.71 (0.39, 1.20)]. Second neoplasms occurred in 31 of 622 cancer survivors [5.0%; 10.7 (7.5, 15.2) cases/1000 PY] and intracranial tumor recurrences in 67 of 823 tumor survivors [8.1%; 16.9 (13.3, 21.5) cases/1000 PY]. All three hemorrhagic stroke cases had risk factors. Conclusions: GeNeSIS (Genetics and Neuroendocrinology of Short Stature International Study) data support the favorable safety profile of pediatric GH treatment. Overall risk of death or primary cancer was not elevated in GH-treated children, and no hemorrhagic strokes occurred in patients without risk factors. T2DM incidence was elevated compared with the general population, but most cases had diabetes risk factors.

Three novel missense mutations within the LHX4 gene are associated with variable pituitary hormone deficiencies.

CONTEXT: The LHX4 LIM-homeodomain transcription factor has essential roles in pituitary gland and nervous system development. Heterozygous mutations in LHX4 are associated with combined pituitary hormone deficiency. OBJECTIVES: Our objectives were to determine the nature and frequency of LHX4 mutations in patients with pituitary hormone deficiency and to examine the functional outcomes of observed mutations. DESIGN: The LHX4 gene sequence was determined from patient DNA. The biochemical and gene regulatory properties of aberrant LHX4 proteins were characterized using structural predictions, pituitary gene transcription assays, and DNA binding experiments. PATIENTS: A total of 253 patients from 245 pedigrees with GH deficiency and deficiency of at least one additional pituitary hormone was included in the study. RESULTS: In five patients, three types of heterozygous missense mutations in LHX4 that result in substitution of conserved amino acids were identified. One substitution is between the LIM domains (R84C); the others are in the homeodomain (L190R; A210P). The patients have GH deficiency; some also display reductions in TSH, LH, FSH, or ACTH, and aberrant pituitary morphology. Structural models predict that the aberrant L190R and A210P LHX4 proteins would have impaired DNA binding and gene activation properties. Consistent with these models, EMSAs and transfection experiments using pituitary gene promoters demonstrate that whereas the R84C form has reduced activity, the L190R and A210P proteins are inactive. CONCLUSIONS: LHX4 mutations are a relatively rare cause of combined pituitary hormone deficiency. This report extends the range of phenotypes associated with LHX4 gene mutations and describes three novel exonic mutations in the gene.

Temporal changes in insulin-like growth factors I and II and in insulin-like growth factor binding proteins 1, 2, and 3 in human milk.

AIM: To evaluate the postpartum time course of changes in insulin-like growth factors (IGFs) and their binding proteins (IGFBPs). METHODS: Breast milk IGF-I and IGF-II and IGFBP-1, IGFBP-2, and IGFBP-3 levels were determined in 23 women with babies born at term, from day 4 until up to 9 months after birth. RESULTS: The IGFBP-3 levels were highest from day 4 to day 6 and then decreased by days 10-12. In contrast, IGF-I and IGF-II and IGFBP-1 and IGFBP-2 showed little change over the first 2 weeks after birth. Subsequently, all the IGF components showed a moderate decline over approximately the first 1-3 months and then stable levels up to 9 months after birth. CONCLUSION: Although the possibility cannot be excluded that these changes in levels of IGFs and their binding proteins in human milk represent passive loss from the mammary gland, we speculate that higher early levels of the human milk IGF system contribute to maturation of the infant gut.

Genotypes and phenotypes in children with short stature: clinical indicators of SHOX haploinsufficiency.

BACKGROUND: Short stature affects approximately 2% of children, representing one of the more frequent disorders for which clinical attention is sought during childhood. Despite assumed genetic heterogeneity, mutations or deletions of the short stature homeobox-containing gene (SHOX) are found quite frequently in subjects with short stature. Haploinsufficiency of the SHOX gene causes short stature with highly variable clinical severity, ranging from isolated short stature without dysmorphic features to Léri-Weill syndrome, and with no functional copy of the SHOX gene, Langer syndrome. METHODS: To characterise the clinical and molecular spectrum of SHOX deficiency in childhood we assessed the association between genotype and phenotype in a large cohort of children of short stature from 14 countries. RESULTS: Screening of 1608 unrelated individuals with sporadic or familial short stature revealed SHOX mutations or deletions in 68 individuals (4.2%): complete deletions in 48 (70.6%), partial deletions in 4 (5.9%) and point mutations in 16 individuals (23.5%). Although mean height standard deviation score (SDS) was not different between participants of short stature with or without identified SHOX gene defects (-2.6 vs -2.6), detailed examination revealed that certain bone deformities and dysmorphic signs, such as short forearm and lower leg, cubitus valgus, Madelung deformity, high-arched palate and muscular hypertrophy, differed markedly between participants with or without SHOX gene defects (p<0.001). Phenotypic data were also compared for 33 children with Turner syndrome in whom haploinsufficiency of SHOX is thought to be responsible for the height deficit. CONCLUSION: A phenotype scoring system was developed that could assist in identifying the most appropriate subjects for SHOX testing. This study offers a detailed genotype-phenotype analysis in a large cohort of children of short stature, and provides quantitative clinical guidelines for testing of the SHOX gene.

Growth hormone treatment for short stature in children born small for gestational age.

Children born small for gestational age (SGA) who do not show catch-up in the first 2 years generally remain short for life. Although the majority of children born SGA are not growth hormone (GH) deficient, GH treatment is known to improve average growth in these children.Early studies using GH in children born SGA demonstrated increased height velocity, but these effects tended to be short-term with effects decreasing when GH treatment stopped. With refined GH regimens, significant effects on height have been shown, with gains of approximately 1 standard deviation score after 2 years. Studies have also shown that long-term continuous GH therapy can significantly increase final height to within the normal range. GH treatment of children born SGA does not appear to unduly affect bone age or pubertal development. Growth prediction models have been used to identify various factors involved in the response to GH therapy with age at start, treatment duration, and GH dose showing strong effects. Genetic factors such as the exon 3 deletion of the GH receptor may contribute to short stature of children born SGA and may also be involved in the responsiveness to GH treatment, but there remain other unknown genetic and/or environmental factors. No unexpected safety concerns have arisen in GH therapy trials. In particular, no long-term adverse effects have been seen for glucose metabolism, and positive effects have been shown for lipid profiles and blood pressure.GH treatment in short children born SGA has shown a beneficial, growth-promoting effect in both the short-and long-term, and has become a recognized indication in both the US and Europe. Further studies on individualized treatment regimens and long-term safety are ongoing.

Growth response to growth hormone treatment in patients with SHOX deficiency can be predicted by the Cologne prediction model.

Background Growth hormone (GH) treatment in children with short stature homeobox-containing gene (SHOX) deficiency is recognized to increase height velocity (HV) and adult height. Prediction of growth response continues to be a challenge. A comparatively accurate method is the Cologne prediction model developed in children with GH deficiency. The aim was to investigate whether this model also applies to patients with SHOX deficiency. Methods Included were 48 patients with SHOX deficiency confirmed by DNA analysis and treated with 0.05 mg/kg/day of somatropin. Prediction by the Cologne model uses the following variables: relative bone age (BA) retardation, baseline insulin-like growth factor-I (IGF-I), urinary deoxypyridinoline (DPD) cross-links at 4 weeks and HV at 3 months. Results HV and height standard deviation scores (SDS) increased significantly during the first year of treatment. Predicted and observed HV (cm/year) showed a Pearson correlation coefficient of 0.50 (p<0.001; root-mean-square error=1.63) and for first-year change in height SDS a Pearson correlation coefficient of 0.751 (p<0.001; root-mean-square error=0.32). Poor response could be adequately predicted using SDS change, with sensitivity and specificity both above 70% for certain thresholds. CONCLUSIONS: The results demonstrate that the Cologne model can be used to predict growth response in patients with SHOX deficiency with reasonable precision in the first treatment year, comparable to prediction in patients with GH deficiency.

The growth hormone-insulin-like growth factor-I axis in the diagnosis and treatment of growth disorders.

The growth hormone (GH)-insulin-like growth factor (IGF)-I axis is a key endocrine mechanism regulating linear growth in children. While paediatricians have a good knowledge of GH secretion and assessment, understanding and use of measurements of the components of the IGF system are less current in clinical practice. The physiological function of this axis is to increase the anabolic cellular processes of protein synthesis and mitosis, and reduction of apoptosis, with each being regulated in the appropriate target tissue. Measurement of serum IGF-I and IGF-binding protein (IGFBP)-3 concentrations can complement assessment of GH status in the investigation of short stature and contribute to prediction of growth response during GH therapy. IGF-I monitoring during GH therapy also informs the clinician about adherence and provides a safety reference to avoid over-dosing during long-term management.

Growth Hormone Treatment for Short Stature in the USA, Germany and France: 15 Years of Surveillance in the Genetics and Neuroendocrinology of Short-Stature International Study (GeNeSIS).

BACKGROUND/AIMS: To describe characteristics, auxological outcomes and safety in paediatric patients with growth disorders treated with growth hormone (GH), for cohorts from the USA, Germany and France enrolled in GeNeSIS, a post-authorisation surveillance programme. METHODS: Diagnosis and biochemical measurement data were based on reporting from, and GH treatment was initiated at the discretion of, treating physicians. Auxological outcomes during the first 4 years of GH treatment and at near-adult height (NAH) were analysed. Serious and treatment-emergent adverse events were described. RESULTS: Children in the USA (n = 9,810), Germany (n = 2,682) and France (n = 1,667) received GH (dose varied between countries), most commonly for GH deficiency. Across diagnostic groups and countries, mean height velocity standard deviation score (SDS) was > 0 and height SDS increased from baseline during the first 4 years of treatment, with greatest improvements during year 1. Most children achieved NAH within the normal range (height SDS >-2). No new or unexpected safety concerns were noted. CONCLUSION: GH treatment improved growth indices to a similar extent for patients in all three countries despite variations in GH doses. Data from these three countries, which together contributed > 60% of patients to GeNeSIS, indicated no new safety signals and the benefit-risk profile of GH remains unchanged.