Estrogen treatment of tall girls: dose dependency of effects on subsequent growth and IGF-I levels in blood

Consensus guideline for the diagnosis and management of pituitary adenomas in childhood and adolescence: Part 2, specific diseases

Pituitary adenomas are rare in children and young people under the age of 19 (hereafter referred to as CYP) but they pose some different diagnostic and management challenges in this age group than in adults. These rare neoplasms can disrupt maturational, visual, intellectual and developmental processes and, in CYP, they tend to have more occult presentation, aggressive behaviour and are more likely to have a genetic basis than in adults. Through standardized AGREE II methodology, literature review and Delphi consensus, a multidisciplinary expert group developed 74 pragmatic management recommendations aimed at optimizing care for CYP in the first-ever comprehensive consensus guideline to cover the care of CYP with pituitary adenoma. Part 2 of this consensus guideline details 57 recommendations for paediatric patients with prolactinomas, Cushing disease, growth hormone excess causing gigantism and acromegaly, clinically non-functioning adenomas, and the rare TSHomas. Compared with adult patients with pituitary adenomas, we highlight that, in the CYP group, there is a greater proportion of functioning tumours, including macroprolactinomas, greater likelihood of underlying genetic disease, more corticotrophinomas in boys aged under 10 years than in girls and difficulty of peri-pubertal diagnosis of growth hormone excess. Collaboration with pituitary specialists caring for adult patients, as part of commissioned and centralized multidisciplinary teams, is key for optimizing management, transition and lifelong care and facilitates the collection of health-related quality of survival outcomes of novel medical, surgical and radiotherapeutic treatments, which are currently largely missing.

17β-Estradiol regulates rat growth plate chondrocyte apoptosis through a mitochondrial pathway not involving nitric oxide or MAPKs

Estrogens cause growth plate closure in both males and females, by decreasing proliferation and inducing apoptosis of postproliferative growth plate chondrocytes. In vitro studies using 17β-estradiol (E(2)) conjugated to bovine serum albumin (E(2)-BSA) show that rat costochondral growth plate resting zone chondrocytes also respond to E(2). Moreover, they are regulated by E(2)-BSA via a protein kinase C and ERK MAPK signaling pathway that is functional only in female cells. To better understand how E(2) regulates apoptosis of growth plate chondrocytes, rat resting zone chondrocytes cells were treated with E(2) or E(2)-BSA. E(2) caused apoptosis in male and female resting zone and growth zone chondrocytes in a dose-dependent manner, based on elevated DNA fragmentation, terminal deoxynucleotidyl transferase dUTP nick end labeling staining and caspase-3 activation. E(2) also up-regulated p53 and Bax protein (Bcl-2-associated X protein) levels and induced release of cytochrome C from the mitochondria, indicating a mitochondrial apoptotic pathway. The apoptotic effect of E(2) did not involve elevated nitric oxide production or MAPKs. It was reduced by ICI 182780, which is an estrogen receptor (ER) antagonist and blocked by antibodies to Erα36, a membrane-associated ER. E(2)-BSA reduced cell viability and increased caspase-3 activity; ICI 182780 had no effect, but anti-ERα36 antibodies blocked the effect. The results indicate that estrogen is able to directly affect the cell population kinetics of growth plate chondrocytes by regulating apoptosis, as well as proliferation and differentiation in both resting zone and growth zone cells. They also have provided further information about the physiological functions of estrogen on longitudinal bone growth.

The role of sex steroids in controlling pubertal growth

Longitudinal growth, which is primarily due to chondrocytic activity at the level of the epiphyseal growth plate, is influenced by many hormones and growth factors in an endocrine and paracrine manner. Their influence is even more complex during the accelerated growth period of puberty that accounts for about 20% of final adult height. Although abnormalities of growth during puberty are very common, the underlying mechanisms that govern the beginning and cessation of pubertal growth at the level of the growth plate are poorly understood. Sex steroids play a crucial role in pubertal growth both at the systemic level via the GH/IGF-1 axis and at the local level of the epiphyseal growth plate. In both sexes it is now accepted that oestrogen is the critical hormone in controlling growth plate acceleration and fusion. This paper reviews the mechanisms that influence pubertal growth and the problems that are associated with disorders of gonadal function.

Sotos Syndrome: A case report

Sotos Syndrome is a genetic condition characterized by accelerated bone development, abnormal craniofacial morphology and psychomotor developmental retardation. The behavioral problems usually associated with the syndrome include poor social skills, anxiety and/or irritability. Oral findings include prognathism and a high-arched palate with premature eruption of the teeth. Delayed psychomotor development increases the risk for caries. A personalized preventive treatment plan with close supervision of the patient's oral health care is required. This paper documents a child diagnosed with Sotos Syndrome and describes the primary clinical features, the disease-specific craniofacial, oral and dental findings, and dental care management of this patient.

Effects of growth reduction therapy using high-dose 17beta-estradiol in 26 constitutionally tall girls

OBJECTIVE

The efficacy and safety of height-limiting therapy with high-dose 17beta-oestradiol in girls with constitutionally tall stature (CTS) are controversial. We evaluated the effectiveness of high-dose 17beta-oestradiol in premenarchal girls with CTS treated until their bone age reached 14 years.

DESIGN

We retrospectively reviewed the medical records of the girls managed between 1989 and 2000 with high-dose 17beta-estradiol for CTS with a predicted final height greater than +3SDs.

PATIENTS

Twenty-six girls met our inclusion criteria. At baseline, mean chronological age was 12.06 +/- 1.51 years and mean height was 171.1 +/- 6.5 cm with a height standard deviation score of 4.5 +/- 0.24, and mean predicted final height was 183.0 +/- 4.2 cm. Treatment was stopped when bone age reached 14 years; mean treatment duration was 1.62 +/- 0.76 years.

MEASUREMENTS

The following were obtained at 6-month intervals: height, body weight, Tanner stage, bone age, plasma cholesterol and triglycerides, plasma glucose and side effects. A mailed questionnaire on final height and satisfaction was sent 2 years after treatment discontinuation (response rate, 24/26). Results Final height was significantly (P < 0.001) reduced, by 2.4 +/- 3.2 cm, as compared to predictions. High-dose 17beta-estradiol therapy decreased growth velocity and significantly increased skeletal maturation (P < 0.001). Linear growth after treatment discontinuation was 3.3 +/- 1.9 cm. No serious side effects were recorded. Most of the patients were satisfied with the treatment.

CONCLUSION

High-dose 17beta-estradiol was moderately effective in reducing final height and should probably be reserved for selected patients, particularly as knowledge on potential long-term side effects is lacking.

Overgrowth

The predominant influences on fetal growth are maternal and placental factors. Post-natal growth is regulated by a complex interaction between genetic, environmental and hormonal influences. The role of the growth hormone insulin-like growth factor (GH-IGF) system is explored, including the emerging role of IGF-2 in fetal growth. Increasing understanding of the genetics of overgrowth and short stature syndromes is contributing greatly to basic understanding of growth regulation. A range of prenatal overgrowth syndromes is discussed, including those associated with neonatal hyperinsulinism and hypoglycaemia.Post-natal overgrowth may be caused by a diverse range of normal variant conditions, endocrine disorders, chromosomal abnormalities and other genetic syndromes. An approach to diagnosis is presented and major conditions discussed in detail. Sex-steroid therapy for height limitation continues to be a controversial area with uncertainty about height prediction, benefits achieved and possible long-term side-effects.

Bone age progression during five years of substitutive therapy for the induction of puberty in thalassemic girls--effects on height and sitting height

It is known that in thalassemic patients there is a disproportion between lower and upper segments whose causes have not yet been identified. We evaluated whether the administration of estrogens to induce puberty in hypogonadic thalassemic girls caused an inappropriate acceleration of bone maturation and whether this had a negative influence on final and sitting height.

MATERIALS AND METHODS

Twelve thalassemic patients with spontaneous puberty (Group A) and seven patients with hypogonadism (Group B) were studied. The mutations of the beta gene were identified by DNA analysis. We took into account four observations, ranging from the onset of spontaneous puberty in group A or the start of substitutive therapy in group B, to 5 years later. At each observation we considered: chronological age (CA), bone age (BA), height (Ht) expressed in cm and as standard deviation score (HtSDS) calculated with respect to CA (HtSDSCA) and BA (HtSDSBA), growth spurt, sitting height, expressed as SDS (SH-SDS), and height gain (HG). The delta BA and delta CA were calculated between the first and the final observation values to evaluate the bone age acceleration (delta BA/delta CA).

RESULTS

No acceleration of BA was noted. delta BA/delta CA was 0.98 +/- 0.1 in group A and 0.89 +/- 0.1 in group B (p > 0.05). All patients in group B had the most severe form (beta degree/beta degree) of thalassemia. During the final observation, SH-SDS was -1.43 +/- 1.2 and -2.9 +/- 0.6 in group A and B respectively (p < 0.002), while no difference between the two groups for HtSDSCA and HtSDSBA was observed. HG was greater in group A than in group B (17.7 +/- 5.4 cm vs 10.8 +/- 5.2 cm) (p < 0.002), such as the spurt 8.6 +/- 1.4 cm (group A) and 6.1 +/- 2.6 cm (group B) (p < 0.05).

CONCLUSIONS

Girls with hypogonadism did not show an inappropriate acceleration of BA, as they reached near final height similar to girls with spontaneous puberty. The auxological parameters showed a more severe body disproportion with the prevalence of the lower segment in the hypogonadic girls. This could be explained by a higher degree of bone marrow hyperplasia related to the most severe form of thalassemia and a higher blood consumption. As a consequence, damage at the vertebral level might determine an inability of the bone tissue to respond to estrogens. We suggest beginning estrogen therapy earlier in order to obtain better truncal growth.

Growth in Sotos syndrome

Although there are several reports on infant and childhood growth in patients with Sotos syndrome, there is little information on the final height achieved and puberty. Growth data on 40 patients (20 female and 20 male) aged 2-31 years were collected. These showed that patients with Sotos syndrome are excessively tall at birth, during infancy, and during childhood. Disproportionately long limbs constitute much of the increase in stature. However, the combination of advanced bone age and early onset of menarche led to a mean (SD) final height of 172.9 (5.7) cm in women. This is within the normal range for the population. Most of the men also attained a final height (mean, 184.3 cm; SD, 6.0) within the normal range, although exceptions were more likely in men than in women. Therefore, these results show that most patients with Sotos syndrome do not require intervention to limit their adult height.

Do changes in growth hormone levels correlate with IGF-I levels in patients undergoing IVF-ET?

It has been suggested that adjunctive growth hormone (GH) therapy improves ovarian response and in vitro fertilization (IVF) outcome in specific groups of patients. The correlation between insulin-like growth factor (IGF) and GH is well established. The aim of this study was to determine whether changes in plasma GH correlate with IGF blood levels in patients during IVF treatment. Thirty-six women undergoing IVF and embryo transfer (ET) were examined. Ovarian stimulation was carried out by gonadotropin-releasing hormone agonists (GnRHa) and gonadotropins. Blood was drawn at the early and late follicular phase, on the day of human chorionic gonadotropin (hCG) injection and at the mid- and the late luteal phases. The samples were assayed for IGF-I, IGF-II, IGF-binding protein-3 (IGF BP-3), GH and estradiol. According to the IGF-I and GH plasma levels, patients were divided into three major groups: Group I consisted of patients in whom peak levels of GH reached more than 4 ng/ml and IGF-I decreased significantly. In this group, estradiol levels were 1863 +/- 149 pg/ml. Group II consisted of patients in whom peak blood GH levels did not exceed 2.5 ng/ml and the IGF-I level remained unchanged. In this group estradiol levels were 630 +/- 57 pg/ml. Group III consisted of patients in whom blood GH levels were low and remained unchanged while estradiol levels were 1600 +/- 420 pg/ml. In this group no significant increase in IGF-levels were observed. There was no significant change in the levels of either IGF-II or IGF BP-3 in any of the groups. We can conclude that (1) there is a negative correlation between GH and IGF-I plasma levels in patients undergoing controlled ovarian hyperstimulation (COH)-IVF, when levels of estradiol and GH are elevated; (2) plasma levels of IGF-I under ovarian hyperstimulation are probably regulated by a multifactorial system; and (3) no correlation was found between the plasma levels of IGF-I and those of IGF-II and IGF BP-3 in all patient groups.

The effect of a continuous infusion of a somatostatin analogue (octreotide) for two years on growth hormone secretion and height prediction in tall children

OBJECTIVE

Strategies to limit the final height of tall children have centred on the use of high doses of sex steroids to advance skeletal maturation. This limits therapy to the peripubertal years whereas the greatest gain in height is in the prepubertal years. Prepubertal growth is largely GH dependent and previous work has documented modulation of GH secretion by once or twice daily subcutaneous injection of the somatostatin analogue octreotide. In this study we have determined the effects of a nocturnal infusion of octreotide on height prediction, GH and TSH secretion in tall children.

DESIGN

A patient controlled study in which height prediction and 24-hour GH and TSH secretion were compared prior to and during the course of a 2-year treatment programme with a nocturnal infusion of octreotide in a dose of 1-1.5 micrograms/kg body weight given subcutaneously.

PATIENTS

Nine tall children (4M; 5F) aged 7-14 years with final height predictions of 179 cm or greater in the girls and between 183 and 202 cm in the boys were studied.

MEASUREMENTS

Height prediction using the Tanner-Whitehouse system prior to and at the end of 2 years of treatment. Twenty-four-hour serum GH and TSH concentration profiles, thyroxine, IGF-I and GH responses to GHRH(1-29)NH2 were studied prior to and at the end of the first year of therapy.

RESULTS

Treatment with octreotide led to a significant reduction in height prediction in 7 of the 8 children who completed treatment (median reduction 3.5 cm, range +2.8 to -11.5; Wilcoxon, P = 0.05). Twenty-four-hour mean serum GH concentration decreased by 50% (MANOVA, P = 0.03) during therapy and this was accompanied by an increase in the percentage of samples giving values less than 0.5 mU/l (MANOVA, P = 0.02). There was no overall change in the serum GH response to GHRH(1-29)NH2 or serum IGF-I concentrations. Nocturnal serum TSH concentrations were reduced to levels observed during the daytime but these changes had no effect on serum thyroxine values. One patient developed gallstones during the course of therapy.

CONCLUSIONS

A nocturnal infusion of octreotide reduces GH secretion and height prediction in tall children. Therapy with somatostatin analogues allows a reduction in growth rate to be instigated in the prepubertal years reducing the actual height from which will commence the pubertal growth spurt.

Impact of different doses of ethinyl oestradiol on reduction of final height in constitutionally tall girls

Fifty-two tall girls were treated for constitutionally tall stature with different ethinyl oestradiol (EE) dosages. They were divided into three different treatment groups: group B (100 micrograms EE/day; n = 11); group C (300 micrograms; n = 25) and group D (500 micrograms; n = 16) and compared with an untreated group A (n = 21) matched for age, height, bone age (BA) and height prediction. Using the height prediction method TW II, EE treatment reduced final height compared with the untreated girls in a weak dose-dependent manner, 2.3 cm (100 micrograms/day), 3.0 cm (300 micrograms/day), and 3.8 cm (500 micrograms/day). Such a dose dependency was not found on applying the Bayley-Pineau height prediction method (100 micrograms/day; 4.1 cm; 300 micrograms/day: 4.2 cm; 500 micrograms/day: 4.5 cm). However, there was a striking inverse correlation of the BA at the onset of treatment with the height reduction achieved using the TW II method (r: -0.43; P < 0.001). Importantly, girls with a BA below 12 years at the onset of treatment experienced a height reduction of more than 6 cm. CONCLUSION The EE dose used in the range of 100-500 micrograms/day is not crucial for the amount of height reduction in tall girls. In general high dose EE treatment should be given restrictively, and especially so in girls with a BA (TW2 RUS-ZH) above 12.0 years.

Development of a highly sensitive and specific assay for plasma ethinylestradiol using combined extraction, liquid chromatography and radioimmunoassay

A highly sensitive and specific assay for ethinylestradiol (EE2) in human plasma was developed. The assay procedure combined solid-phase extraction of plasma samples, isolation of extracted EE2 by liquid chromatography (LC), and radioimmunoassay. Samples were extracted to remove polar plasma constituents and steroid binding proteins. Chromatography was employed to separate EE2 from other steroids that were candidates for assay cross-reactivity. The radioimmunoassay was shown to be sensitive (lower limit of quantitation = 2 pg ml-1 EE2 in plasma) and accurate (mean accuracy = 102%). Recovery of EE2 through extraction and LC steps was 76.1 +/- 4.5% (mean +/- SD; n = 42). Overall assay intra- and inter-assay coefficients of variation were 3.6 and 8.9%, respectively. The analyte was stable in assay buffer and assay accuracy was influenced minimally by four sample freeze-thaw cycles. This assay protocol enables the precise monitoring of low circulating levels of EE2, a prominent and potent synthetic oestrogen.

Estradiol inhibits growth hormone receptor gene expression in rabbit liver

We studied the ontogeny of GH receptor mRNA levels and the effect of exogenous estradiol administration on GH receptor mRNA levels in rabbit liver. A solution hybridization-RNase protection assay revealed a predominant 370-base long protected band corresponding to the mRNA encoding the transmembrane GH receptor, and a 241-base long protected band, representing about 9.0%, with the predicted size for the truncated form of the GH receptor. To study the developmental profile of GH receptor expression, we studied 12 female rabbits, at ages 1, 3, 5 and 7 months. Maximal GH receptor mRNA levels were observed in 3-month-old animals and decreased in 7-month-old animals. To investigate the effect of estradiol, 8-week-old immature female rabbits were randomly divided into five groups, and received subcutaneous pellets containing either placebo or estradiol at doses of 0.1, 0.5, 1.5 and 5.0 mg for 3 weeks. Exogenous administration of estradiol, at doses that resulted in physiological circulating levels, induced a reduction in GH receptor expression, measured both by GH binding (36 and 46%), and GH receptor mRNA levels (38 and 87%), in animals receiving pellets containing 1.5 and 5.0 mg of estradiol, respectively. We conclude that estradiol decreases GH receptor expression in rabbit liver. The results of our study suggest that there is an inverse relationship between circulating estrogen concentrations and liver GH receptor expression.