Margaret Cristina da Silva Boguszewski

Children born small-for-gestational age: Postnatal growth and hormonal status

It is generally recognized that children born small-for-gestational age (SGA) have a 5–7 times higher risk of short stature than children born at normal size. It has been suggested that the programming of the endocrine axes occurs during critical phases of fetal development and is affected by intrauterine growth retardation. This study was undertaken to characterize the postnatal growth pattern and the final height of children born SGA, as part of a population- based study (n = 3,650), from birth to final height, and to evaluate the hormonal status in another group of prepubertal children born SGA (n = 134) without postnatal catch-up growth. The majority (88%) of ‘healthy’ full-term singleton SGA infants achieved catch-up growth during the first 2 years of life, and most of the increase in height occurred by 2 months of age. The SGA children who remained short at 2 years of age had a higher risk of short stature later in life. The risk of having a short final height (<–2 SDS) was five times higher for children with a low birth weight and seven times higher for those with a low birth length in comparison with children with a normal birth size. Moreover, about 20% of all children of short stature were born SGA. As a group, children born SGA will have a final height, expressed in SDS, as they had during the prepubertal years. This is in contrast to children, who became short postnatally. During puberty, these short children will have a mean height gain of 0.6 SDS for girls and 0.7 SDS for boys. The mean estimated secretion rate for growth hormone (GH) was lower in the short children born SGA compared with the reference groups born at an appropriate size for gestational age, of either short (p < 0.05) or normal stature (p < 0.001). Moreover, in the youngest children born SGA (2–6 years of age) a different pattern of GH secretion was found, with a high basal GH level, low peak amplitude, and high peak frequency. The majority of the children born SGA had levels of GH-binding protein within the range previously reported for normal children. However, the levels of insulin-like growth factor I (IGF-I), IGF-binding protein-3 (IGFBP-3) and leptin were significantly reduced compared with the reference values (p < 0.001, p < 0.01 and p < 0.001, respectively). In conclusion, the low spontaneous GH secretion rate and a disturbed GH secretion pattern, together with low serum levels of IGF-I, IGFBP-3 and leptin, might contribute to the reduced postnatal growth in some of the subgroup of children born SGA who remained short during childhood.

Adrenal steroid hormones in short children born small for gestational age

Programming of the endocrine axis has been postulated to occur during critical phases of fetal development and is affected by intrauterine growth retardation. The aim of this study was to investigate this hypothesis with regard to adrenal steroid hormones. Thus, serum cortisol and dehydroepiandrosterone sulphate (DHEAS) levels were compared in children born small for gestational age (SGA) who remained short and in children born at an appropriate size for gestational age (AGA), of both short and normal stature.

GH safety workshop position paper: a critical appraisal of recombinant human GH therapy in children and adults.

Recombinant human GH (rhGH) has been in use for 30 years, and over that time its safety and efficacy in children and adults has been subject to considerable scrutiny. In 2001, a statement from the GH Research Society (GRS) concluded that ‘for approved indications, GH is safe’; however, the statement highlighted a number of areas for on-going surveillance of long-term safety, including cancer risk, impact on glucose homeostasis, and use of high dose pharmacological rhGH treatment. Over the intervening years, there have been a number of publications addressing the safety of rhGH with regard to mortality, cancer and cardiovascular risk, and the need for long-term surveillance of the increasing number of adults who were treated with rhGH in childhood. Against this backdrop of interest in safety, the European Society of Paediatric Endocrinology (ESPE), the GRS, and the Pediatric Endocrine Society (PES) convened a meeting to reappraise the safety of rhGH. The ouput of the meeting is a concise position statement.

Vitamin D deficiency in girls from South Brazil: a cross-sectional study on prevalence and association with vitamin D receptor gene variants

BackgroundVitamin D deficiency has been associated with a multitude of disorders including diabetes, defective insulin secretion as well as rickets and poor bone health. Vitamin D is also a concern during childhood and adolescence and has been reported in girls from South Brazil. We determined the prevalence of vitamin D deficiency in girls from South Brazil and investigated whether the genotypic distribution of the BsmI, ApaI and TaqI polymorphisms of the VDR gene and their haplotypes were associated with vitamin D levels.MethodsCross-sectional study including 234 apparently healthy girls aged 7 to 18 years. Height and weight were measured for calculation of body mass index (BMI) percentiles for age. Plasma levels of 25-hydroxyvitamin D [25(OH)D] were assessed. Participants were genotyped for ApaI (rs7975232), TaqI (rs731236), and BsmI (rs1544410) SNPs.ResultsThe median and interquartile range (25-75%) of BMI percentile was 62.0 (33.3 – 84.9). The frequency of overweight/obesity was 24.9%. Circulating levels of 25(OH)D (≥ 30 ng/mL) were adequate in 9.4%; insufficient in 54.3% (20–29 ng/mL); and deficient in 36.3% (< 20 ng/mL). Genotype frequencies were GG = 47.0%, GA = 41.5%, and AA = 11.5% for BsmI; GG = 16.7%, GT = 52.6%, and TT = 30.8% for ApaI; TT = 46.2%, TC = 44.9% and CC = 9.0% for TaqI. Genotypes with no gene variance (ancestral wild genotype) of BsmI (GG vs. GA + AA, two-tailed Student’s t-test p < 0.001), ApaI (GG vs. GT + TT, two-tailed Student’s t-test p = 0.031) and TaqI (TT vs. TC + CC, two-tailed Student’s t-test p = 0.005) SNPs and the GGT haplotype (two-tailed Student’s t-test p = 0.036) were significantly associated with lower 25(OH)D levels.Conclusions25-hydroxyvitamin D deficiency and insufficiency were highly prevalent in this sample. The BsmI, ApaI and TaqI wild variants of the VDR gene, as well as the GGT haplotype, were associated with lower vitamin D levels, suggesting that VDR gene polymorphisms could be linked to higher susceptibility to vitamin D deficiency in a sub-population of children and adolescents.

In vitro and in vivo responses to short-term recombinant human insulin-like growth factor-1 (IGF-I) in a severely growth-retarded girl with ring chromosome 15 and deletion of a single allele for the type 1 IGF receptor gene

Patients with single allele defects in the gene encoding the type 1 IGF receptor have been reported to have growth failure, but fibroblasts from affected patients have not exhibited insensitivity to the effects of IGF‐I in vitro. The in vitro and in vivo responses to short‐term recombinant human IGF‐I (rhIGF‐I) in a severely growth‐retarded girl with ring chromosome 15 and deletion of a single allele for the type 1 IGF receptor gene have been investigated.

Hormonal status of short children born small for gestational age

The present study was undertaken to evaluate the hormonal status in a subgroup of prepubertal children born small for gestational age (SGA) who lacked postnatal catch‐up growth. In this subgroup, a reduced rate of growth hormone (GH) secretion was found, compared with reference groups of healthy children born appropriate for gestational age, of either normal or short stature at the time of investigation. In addition, an abnormal pattern of GH secretion was observed in short children born SGA, which was most pronounced in the younger children, and involved an increased frequency of GH peaks of low amplitude, combined with increased baseline secretion. Levels of insulin‐like growth factor I (IGF‐I) and IGF‐binding protein‐3 were also reduced in short children bora SGA, compared with the reference groups. These findings may explain, in part, the lack of postnatal catch‐up growth in short children born SGA. □ Small for gestational age, growth hormone secretion, growth hormone‐binding protein, insulin‐like growth factor I, insulin‐like growth factor‐binding protein‐3

Growth Hormone Research Society perspective on the development of long-acting growth hormone preparations

Objective The Growth Hormone (GH) Research Society (GRS) convened a workshop to address important issues regarding trial design, efficacy, and safety of long-acting growth hormone preparations (LAGH). Participants A closed meeting of 55 international scientists with expertise in GH, including pediatric and adult endocrinologists, basic scientists, regulatory scientists, and participants from the pharmaceutical industry. Evidence Current literature was reviewed for gaps in knowledge. Expert opinion was used to suggest studies required to address potential safety and efficacy issues. Consensus process Following plenary presentations summarizing the literature, breakout groups discussed questions framed by the planning committee. Attendees reconvened after each breakout session to share group reports. A writing team compiled the breakout session reports into a draft document that was discussed and revised in an open forum on the concluding day. This was edited further and then circulated to attendees from academic institutions for review after the meeting. Participants from pharmaceutical companies did not participate in the planning, writing, or in the discussions and text revision on the final day of the workshop. Scientists from industry and regulatory agencies reviewed the manuscript to identify any factual errors. Conclusions LAGH compounds may represent an advance over daily GH injections because of increased convenience and differing phamacodynamic properties, providing the potential for improved adherence and outcomes. Better methods to assess adherence must be developed and validated. Long-term surveillance registries that include assessment of efficacy, cost-benefit, disease burden, quality of life, and safety are essential for understanding the impact of sustained exposure to LAGH preparations.

Insulin-Like Growth Factor-1, Leptin, Body Composition, and Clinical Status Interactions in Children with Cystic Fibrosis

Background/Aims: Children with cystic fibrosis (CF) are of increased risk of reduced fat body mass (FBM) and lean body mass (LBM). Serum concentrations of insulin-like growth factor-1 (IGF-1)and leptin could be markers of LBM and/or FBM depletion. To evaluate the relationships between disease activity, body composition, IGF-1and leptin concentrations in CF children. Methods: A cross-sectional study with 26 CF children aged 5.0–15.5 years and 33 healthy controls, mean age 9.4 years. Body composition was evaluated by dual-energy X-ray absorptiometry. Fasting blood samples were analyzed for leptin, IGF-1and IGFBP-3. Results: FBM standard deviation score (SDS; CF boys –0.02 ± 0.88 vs. 0.78 ± 0.65, p < 0.01; CF girls –0.37 ± 1.15 vs. 0.70 ± 0.97, p < 0.05), leptin concentration (CF boys 2.07 ± 0.79 vs. 3.07 ± 1.28 ng/ml, p < 0.05; CF girls 2.71 ± 0.86 vs. 5.00 ± 2.95 ng/ml, p < 0.05) and IGF-1SDS (CF boys –1.43 ± 1.50 vs. –0.32 ± 0.88, p < 0.05; CF girls –0.66 ± 1.66 vs. 0.64 ± 0.57, p < 0.01) were lower in CF children compared to controls. Shwachman score was the strongest predictor of lean body mass (R = 0.63). Leptin levels explain 60% of the variability in FBM. Conclusion: Serum concentrations of IGF-1 and leptin are decreased in children with CF and are associated with clinical conditions and body composition.

Growth hormone status in six children with fetal alcohol syndrome

Objective:Prenatal alcohol exposure may cause fetal alcohol syndrome (FAS), which is associated with pre‐ and postnatal growth retardation. Materials and methods: Spontaneous 24‐h growth hormone (GH) secretion was measured in six prepubertal short children with FAS (two boys and four girls) aged 4‐14 years. The response to a GH stimulation test, and levels of insulin‐like growth factor‐I (IGF‐1) and IGF‐binding protein‐3 (IGFBP‐3) were also measured. Comparisons were made between the children with FAS and healthy children of both normal and short stature, as well as children born small for gestational age (SGA). Results: There were no differences in the mean area under the curve above the baseline or the maximum level of GH during a 24‐h period (GHmax) between the children with FAS and the reference groups. However, the estimated rate of spontaneous 24‐h GH secretion in children with FAS was similar to that of children born SGA, but lower than in children of normal stature (p= 0.02). The plasma concentrations of IGF‐1 and IGFBP‐3 were in the lower parts of the normal range. Conclusion: We conclude that GH secretion in short children with FAS is similar to that in short children born SGA; that is, in the lower range of normal children.

Independent association of clustered metabolic risk factors with cardiorespiratory fitness in youth aged 11-17 years.

Abstract Background: Although the prevalence of metabolic syndrome (MetS) has increased in youth, the potential independent contribution of cardiorespiratory fitness (CRF) to the clustering of metabolic risk factors has received relatively little attention. Aim: This study evaluated associations between the clustering of metabolic risk factors and CRF in a sample of youth. Subjects and methods: Height, weight, BMI, fasting glucose, insulin, HDL-cholesterol, triglycerides and blood pressures were measured in a cross-sectional sample of 924 youth (402 males, 522 females) of 11–17 years. CRF was assessed using the 20-metre shuttle run test. Physical activity (PA) was measured with a 3-day diary. Outcome variables were statistically normalized and expressed as Z-scores. A MetS risk score was computed as the mean of the Z-scores. Multiple linear regression was used to test associations between CRF and metabolic risk, adjusted for age, sex, BMI, PA and parental education. Results: CRF was inversely associated with MetS after adjustment for potential confounders. After adjusting for BMI, the relationship between CRF and metabolic risk has substantially improved. Conclusion: CRF was independently associated with the clustering of metabolic risk factors in youth of 11–17 years of age.