[Once growth hormone, always growth hormone? Transition from growth hormone therapy in childhood to adulthood]

The continuation of growth hormone treatment can be indicated in young adults who have been treated with growth hormone during childhood. However, in a large part of this population the diagnosis cannot be confirmed in adulthood. Therefore a retest procedure has to be performed once the final height has been attained. This procedure is only unnecessary in patients with deficiencies of two or more other pituitary hormone axes. The retest procedure can be performed one to three months after the growth hormone treatment has been discontinued, by means of an insulin tolerance test or, in the case of contraindications, by means of a combined growth hormone-releasing hormone(GHRH)-arginine test. If the growth hormone deficiency diagnosis is re-established, growth hormone treatment can be restarted. Patients are only eligible for a reimbursement of the growth hormone treatment costs from their health insurer, if the treatment indication is validated by the Dutch National Registry of Growth Hormone Treatment in Adults and the treatment results are included in a database. With this database insights into the long-term efficacy and safety of growth hormone treatment can be gained.

[From gene to disease; POU1F1- and PROP1-mutations in pituitary hormone deficiency]

Multiple pituitary hormone deficiency can be caused by mutations in at least three pituitary transcription factors: POU1F1 (formerly called PIT1), PROP1 or HESX1. The role of the various pituitary transcription factors in pituitary ontogeny has been elucidated in part for the mouse. In humans, mutations in POU1F1 result in a total deficiency of growth hormone and prolactin, and a variable deficiency of TSH. Cases of mutations in PROP1 exhibit the same deficiencies, with additional deficiencies of gonadotrophins and a variable deficiency of ACTH. In the Netherlands, cases of multiple pituitary hormone deficiency are not only detected on the basis of the classical signs and symptoms of pituitary deficiency, but also by means of screening on congenital hypothyroidism with an incidence of approximately 1:20,000.

Pubertal development in The Netherlands 1965-1997

We investigated pubertal development of 4019 boys and 3562 girls >8 y of age participating in a cross-sectional survey in The Netherlands and compared the results with those of two previous surveys. Reference curves for all pubertal stages were constructed. The 50th percentile of Tanner breast stage 2 was 10.7 y, and 50% of the boys had reached a testicular volume of 4 mL at 11.5 y of age. Median age at menarche was 13.15 y. The median age at which the various stages of pubertal development were observed has stabilized since 1980. The increase of the age at stage G2 between 1965 and 1997 is probably owing to different interpretations of its definition. The current age limits for the definition of precocious are close to the third percentile of these references. A high agreement was found between the pubic hair stages and stages of pubertal (genital and breast) development, but slightly more in boys than in girls. Menarcheal age was dependent on height, weight, and body mass index. At a given age tall or heavy girls have a higher probability of having menarche compared with short or thin girls. A body weight exceeding 60 kg (+1 SDS), or a body mass index of >20 (+1 SDS), has no or little effect on the chance of having menarche, whereas for height such a ceiling effect was not observed. In conclusion, in The Netherlands the age at onset of puberty or menarche has stabilized since 1980. Height, weight, and body mass index have a strong influence on the chance of menarche.

An analysis of intra-uterine growth retardation in rural Malawi

OBJECTIVE

(1) To describe the sex-specific, birth weight distribution by gestational age of babies born in a malaria endemic, rural area with high maternal HIV prevalence; (2) to assess the contribution of maternal health, nutritional status and obstetric history on intra-uterine growth retardation (IUGR) and prematurity.

METHODS

Information was collected on all women attending antenatal services in two hospitals in Chikwawa District, Malawi, and at delivery if at the hospital facilities. Newborns were weighed and gestational age was assessed through post-natal examination (modified Ballard). Sex-specific growth curves were calculated using the LMS method and compared with international reference curves.

RESULTS

A total of 1423 live-born singleton babies were enrolled; 14.9% had a birth weight <2500 g, 17.3% were premature (<37 weeks) and 20.3% had IUGR. A fall-off in Malawian growth percentile values occurred between 34 and 37 weeks gestation. Significantly associated with increased IUGR risk were primiparity relative risk (RR) 1.9; 95% CI 1.4--2.6), short maternal stature (RR 1.6; 95% CI 1.0--2.4), anaemia (Hb<8 g/dl) at first antenatal visit (RR 1.6; 95% CI 1.2--2.2) and malaria at delivery (RR 1.4; 95% CI 1.0--1.9). Prematurity risk was associated with primiparity (RR 1.7; 95% CI 1.3--2.4), number of antenatal visits (RR 2.2; 95% CI 1.6--2.9) and arm circumference <23 cm (RR 1.9; 95% CI 1.4--2.5). HIV infection was not associated with IUGR or prematurity.

CONCLUSION

The birth-weight-for-gestational-age, sex-specific growth curves should facilitate improved growth monitoring of newborns in African areas where low birth weight and IUGR are common. The prevention of IUGR requires improved malaria control, possibly until late in pregnancy, and reduction of anaemia.

Isolated GH deficiency with dominant inheritance: new mutations, new insights

Autosomal dominantly inherited isolated GH deficiency is caused by mutations of GH-1 that alter the normal structure of GH. We studied 16 familial cases and 1 sporadic case with isolated GH deficiency type II from 1 Dutch and 4 German families by direct sequencing of PCR-amplified genomic DNA and ectopic transcript analysis of lymphocyte mRNA. In addition, the clinical data of the affected individuals were analyzed. Two previously reported mutations and 1 novel splice site mutation in intron III of GH-1 (+1G to C and +1G to A; new, +2T to C) were detected that cause exon 3 skipping. We also discovered a novel G6191 to T missense mutation in exon 4 of GH-1 that changes valine 110, which is highly conserved in mammalian and several nonmammalian GH, to phenylalanine. Splicing of the primary RNA transcript was not affected by this mutation, which is very likely to alter the normal GH structure at the protein level. The onset of growth failure was earlier, and the degree was more severe in affected children with GH-1 splice site mutations compared with those in children with the GH-1 missense mutation. In addition, the severity of the phenotype was variable, even within the same family. The age at diagnosis was between 0.8-9.6 yr (median, 5.1 yr); height at diagnosis was between -2.5 and -8.1 SD score (median, -4.0). Most of the children were lean at diagnosis, with a body mass index ranging from -1.7 to +3.3 SD score (median, -0.5). The 5 affected adults had final heights between -1.8 and -4.5 SD score (median, -3.6), centripetal obesity, and muscular hypotrophy. Before therapy, IGF-I and IGF-binding protein-3 serum levels of all affected children were severely diminished (<<5th percentiles for age). The maximum GH peak in a total of 25 stimulation tests was between 0.1-5.0 microg/liter (median, 0.9), indicating severe GH deficiency. The height of the adenohypophysis studied by magnetic resonance imaging was normal in 2 affected children and mildly decreased in 2 others. Substitution with GH resulted in good catch-up growth in all treated children. Children with severe GH and IGF-I deficiencies, but normal size of the adenohypophysis should be examined for GH-1 splice site and missense mutations. The observed discrepancy between the very homogeneous hormone data proving severe GH and IGF-I deficiencies and the high variability of growth failure even within the same family suggests that the onset and predominance of GH-dependent growth during infancy are individually different and modified by as yet unknown factors.

[Increased prevalence of overweight and obesity in Dutch children, and the detection of overweight and obesity using international criteria and new reference diagrams]

OBJECTIVE

To determine the prevalence of overweight and obesity in Dutch children in 1980 and 1997 according to international criteria, and to design new reference diagrams for overweight and obesity in children.

DESIGN

Descriptive.

METHOD

The prevalence of overweight and obesity, based on height and weight data from the Fourth Dutch Growth Study (1997), was determined according to international criteria for age and sex.

RESULTS

In 1997, the prevalence of overweight and obesity increased in both boys and girls compared to 1980: in 1997, the prevalence of overweight ranged between 7.1 and 15.5% for boys, and between 8.2 and 16.1% for girls. Both the prevalence of overweight and obesity was higher in girls than in boys.

CONCLUSION

By applying the international criteria for overweight and obesity and reference growth diagrams based upon the 1997 Dutch growth study, the prevention and detection of overweight and obesity has to be implemented with vigour in Dutch youth health care.

A randomized controlled trial of three years growth hormone and gonadotropin-releasing hormone agonist treatment in children with idiopathic short stature and intrauterine growth retardation

We assessed the effectiveness and safety of 3 yr combined GH and GnRH agonist (GnRHa) treatment in a randomized controlled study in children with idiopathic short stature (ISS) or intrauterine growth retardation (IUGR). Gonadal suppression, GH reserve, and adrenal development were assessed by hormone measurements in both treated children and controls during the study period. Thirty-six short children, 24 girls (16 ISS/8 IUGR) and 12 boys (8 ISS/4 IUGR), with a height SD score of -2 SD or less in early puberty (girls, B2-3; boys, G2-3), were randomly assigned to treatment (n = 18) with GH (genotropin 4 IU/m(2). day) and GnRHa (triptorelin, 3.75 mg/28 days) or no treatment (n = 18). At the start of the study mean (SD) age was 11.4 (0.56) or 12.2 (1.12) yr whereas bone age was 10.7 (0.87) or 10.9 (0.63) yrs in girls and boys, respectively. During 3 yr of study height SD score for chronological age did not change in both treated children and controls, whereas a decreased rate of bone maturation after treatment was observed [mean (SD) 0.55 (0.21) 'yr'/yr vs. 1.15 (0.37) 'yr'/yr in controls, P < 0.001, girls and boys together]. Height SD score for bone age and predicted adult height increased significantly after 3 yr of treatment; compared with controls the predicted adult height gain was 8.0 cm in girls and 10.4 cm in boys. Furthermore, the ratio between sitting height/height SD score decreased significantly in treated children, whereas body mass index was not influenced by treatment. Puberty was effectively arrested in the treated children, as was confirmed by physical examination and prepubertal testosterone and estradiol levels. GH-dependent hormones including serum insulin-like growth factor I and II, carboxy terminal propeptide of type I collagen, amino terminal propeptide of type III collagen, alkaline phosphatase, and osteocalcin were not different between treated children and controls during the study period. Thus, a GH dose of 4 IU/m(2) seems adequate for stabilization of the GH reserve and growth in these GnRHa-treated children. We conclude that 3 yr treatment with GnRHa was effective in suppressing pubertal development and skeletal maturation, whereas the addition of GH preserved growth velocity during treatment. This resulted in a considerable gain in predicted adult height, without demonstrable side effects. Final height results will provide the definite answer on the effectiveness of this combined treatment.

Quality of life in preschool children born preterm

The relationship of preterm birth to health-related quality of life (HRQoL) was examined for children aged 1 to 4 years. Three gestational age groups with a NICU history were selected, <32 weeks (n=65), 32 to 36 weeks (n=41), 237 weeks (n=54), and a reference group from the open population (n=50). The main instrument was the TNO-AZL Preschool Quality Of Life (TAPQOL) questionnaire, which was completed by the parents. In addition, other outcome measures obtained from parents or neonatologists were investigated. Children born <32 weeks had significantly lower HRQoL than the reference group in the scales for lungs, stomach, eating disorders, motor functioning, communication, and anxiety. Parental feelings towards the child were related to the child's HRQoL. We found differences between the neonatologists' and parents' perceptions of the children's situation, which can have clinical consequences (e.g. different opinions about what needed treatment). Neonatal intensive care after birth has HRQoL implications for all children, particularly in children born at <32 weeks of gestation.

Growth hormone (GH) secretion in patients with an inactivating defect of the GH-releasing hormone (GHRH) receptor is pulsatile: evidence for a role for non-GHRH inputs into the generation of GH pulses

GH secretion is regulated by the interaction of GHRH and somatostatin and is released in 10-20 pulses in each 24-h cycle. The exact roles in pulse generation played by somatostatin, GHRH, and the recently isolated GH-releasing peptide, Ghrelin, are not fully elucidated. To investigate the GHRH-mediated GH secretion in human, we investigated pulsatile, entropic, and 24-h rhythmic GH secretion in two young adults (male, 24 yr; female, 23 yr) from a Moroccan family with a novel inactivating defect of the GHRH receptor gene. Data were compared with values in age- and gender-matched controls. Plasma GH concentration were measured by a sensitive immunofluorometric assay, with a detection limit of 0.01 mU/L. All plasma GH concentrations in the female patient were measurable; in the male patient 30 of 145 samples were at or below the detection limit. GH secretion was pulsatile, with 21 and 23 secretory episodes/24 h in the male and female patients, respectively. The fraction of basal to total GH secretion was raised in both patients by 0.18 and 0.15, respectively. The total 24-h GH production rate was greatly diminished; in the male patient it was 6.9 mU/L (normal values for his age, 26--63 mU/L), and in the female patient it was 4.2 mU/L (normal values for her age, 96--390 mU/L). The nyctohemeral plasma GH rhythm was preserved (P < 0.001), with normal acrophases (0430 and 0218 h in the male and female, respectively). Approximate entropy was greatly elevated in both subjects (0.82 in the male and 1.17 in the female; upper normal values for age and gender, 0.24 and 0.59, respectively). Intravenous injection of 50 microg GHRH failed to increase the plasma GH concentration in both patients, but 100 microg GH-releasing peptide-2 elicited a definite increase (male patient, 0.13 to 1.74 mU/L; female patient, 0.29 to 0.87 mU/L). Both patients had a partial empty sella on magnetic resonance imaging scanning. In summary, the present studies in two patients with a profound loss of function mutation of the GHRH receptor favor the view that in the human the timing of GH pulses is primarily supervised by intermittent somatostatin withdrawal, and the amplitude of GH pulses is driven by GHRH. In addition, we infer that effectual GHRH input controls the GH cell mass and the orderliness of the secretory process.

Development and psychometric evaluation of the TAPQOL: a health-related quality of life instrument for 1-5-year-old children

The 43-item TNO-AZL Preschool Children Quality of Life (TAPQOL) questionnaire was developed to meet the need for a reliable and valid instrument for measuring parent's perceptions of health-related quality of life (HRQoL) in preschool children. HRQoL was defined as health status in 12 domains weighted by the impact of the health status problems on well-being. The aim of this study was to evaluate the psychometric performance of the TAPQOL. A sample of 121 parents of preterm children completed the TAPQOL questionnaire (response rate 88%) as well as 362 parents of children from the general population (response rate 60%). On the base of Cronbach's alpha, item-rest correlation, and principal component analysis, the TAPQOL scales were constructed from the data for the preterm children sample. The psychometric performance of these scales was evaluated for both the preterm children sample and the general population sample. Cronbach's alpha ranged from 0.66 to 0.88 for the preterm children sample and from 0.43 to 0.84 for the general population sample. The unidimensionality of the separate scales was confirmed by principal component analysis for both the preterm children sample and the general population sample. Spearman's correlation coefficients between scales were, on average, low. T-tests showed that the very preterm children, the children with chronic diseases, the less healthy and the less happy children had lower mean scores on the TAPQOL scales than healthy children, indicating a worse quality of life. This study shows that the TAPQOL is a reliable and valid parent's perception of HRQoL in preschool children. More research is needed to evaluate the psychometric performance of the TAPQOL in different clinical populations.

The estrogen receptor in the growth plate: implications for pubertal growth

It is well established that estrogen is essential for statural growth during puberty, but until recently it was generally accepted that the role of estrogen was negligible during puberty in boys. Clinical findings in three male patients, one with an inactivating mutation in the estrogen receptor and two with P-450 aromatase deficiency, have, however, advanced our knowledge of the role of estrogen in the male. It has become apparent that estrogen (1) initiates the pubertal growth spurt, (2) causes growth plate fusion at the end of puberty, and (3) augments accrual of bone during puberty. Two estrogen receptors (alpha and beta) mediate the actions of estrogen, and the presence of both has been demonstrated in the growth plate. The mechanism by which estrogen acts locally on the growth plate, however, remains largely unknown. With the recent development of knockout models for both estrogen receptors, attempts are being made to unravel the local actions of estrogen in order to characterize further their roles in the regulation of longitudinal growth.

[Implications of the Barker hypothesis for general practitioners]

The Barker hypothesis states that there are foetal origins of adult disease. The hypothesis is primarily based on epidemiological associations between indicators of foetal malnutrition and mortality and morbidity in adulthood. The first association reported was between birth weight and coronary heart disease. Similar associations were found between birth weight and stroke, hypertension, type 2 diabetes mellitus, insulin resistance, serum lipids, and premature pubarche. In non-industrialized countries the associations appear to be even stronger. Although the Barker hypothesis has been criticized, the evidence from epidemiological studies and animal experiments appears sufficient to test it further and to consider the possible consequences for the physician. The first consequence could be that in taking a medical history from adults the physician should collect information about intrauterine growth. To facilitate this, communication between obstetricians, specialists in preventive child health care and paediatricians on the one hand and general practitioners and physicians on the other ought to be improved. A low birth weight, particularly smallness for gestational age, can be communicated to the adult patient as a potential risk factor for the diseases mentioned above and an extra reason to abstain from smoking and to avoid overweight.

Quality of life in short adults

The use of (costly) growth hormone (GH) treatment in short children is often justified by the assumption that short stature considerably reduces quality of life in adults. We tested this assumption in 5 groups of short adults: 25 patients with isolated GH deficiency; 17 male patients with childhood onset renal failure; 25 women with Turner syndrome and 26 patients who were presented as a child to a paediatrician for idiopathic short stature. A group of 44 short individuals with presumably idiopathic short stature, who had not been presented to a paediatrician for short stature, was sampled from the general population ('normal shorts'). We measured quality of life in terms of socio-economic variables, the Nottingham Health Profile and time trade-off. The mean height of most groups was close to the 3rd percentile. The chance of having a partner was low for all groups, except for the normal shorts. Problems with job application were only reported in Turner syndrome. The scores on the Nottingham Health Profile were all within the normal range, but GH-deficient adults had a higher score on the domain energy than normal shorts. Women with Turner syndrome, individuals with renal failure, and those with idiopathic short stature had a wish to be taller, with an estimated reduction in quality of life of 2-4% (time trade-off). As the normal shorts did not show any sign of a reduced quality of life, we falsify the assumption of a direct relation between short stature and quality of life. The complaints of patients with idiopathic short stature around the 3rd percentile seem to be the result of unsuccessful coping strategies.

Body mass index in growth hormone deficient children before and during growth hormone treatment

Growth hormone deficiency (GHD) is associated with truncal obesity. We aimed at identifying factors that determine the body mass index (BMI) of untreated GHD children and the changes in BMI during 2 years of GH therapy in 348 Dutch GHD children registered in the National GH Registration Database. BMI was expressed as a standard deviation score (SDS). Before GH therapy, the mean (95% CI) BMI-SDS in all GHD children (0.09 (-0.05 to 0.24) SDS) was comparable to normal children. Patients with GHD due to a cranial tumour have a higher BMI (1.03 (0.69-1.36) SDS; p < 0.0001) as well as those with multiple pituitary hormone deficiencies (0.35 (0.14-0.57) SDS; p = 0.005) and patients who are in puberty at start of GH therapy (0.60 (0.13-1.08) SDS; p = 0.036). During GH therapy BMI initially decreased to reach a nadir of -0.28 (-0.35 to -0.21) SDS at 6 months. Thereafter BMI progressively increased to -0.09 (-0.18 to -0.04) SDS after 24 months. A higher initial BMI-SDS resulted in a larger decrease in BMI-SDS. We showed that this can be sufficiently explained by a regression to the mean effect.

Health status development in a cohort of preterm children

OBJECTIVE

To determine the impact of preterm birth on health status (HS) development at the ages of 5 and 10 years in a cohort of children born before term.

SAMPLE

Six hundred eighty-eight children, born in 1983 with a gestational age of <32 weeks and a birth weight of <1500 g.

DESIGN

Prospectively collected HS variables, obtained from the parents, were analyzed in a longitudinal perspective by using principal component analyses.

RESULTS

One third of the sample had minor to severe HS problems at both ages of measurement. One third had problems on one assessment only. The remainder of the sample had no HS problems at either age. The analyses grouped the HS variables into 3 combinations. Problems in basic functioning, such as mobility or speech, decreased with age. Negative moods substantially increased, and concentration problems increased slightly. Specifically at risk were preterm born children with handicaps, boys, and children who were small for gestational age.

CONCLUSION

According to the parents, one third of the cohort had no HS problems at either age. The pattern of HS problems of the preterm born children changed between 5 and 10 years of age.

High-dose growth hormone therapy in idiopathic short stature

This article reviews the available data on the effect of growth hormone (GH) administration on the growth of children with idiopathic short stature. The 1st year growth response appears clearly dose dependent, if the mean values from various clinical trials are combined. Dose dependency has also been shown in prospective trials. The dose dependency of the long-term growth response was less convincing in a large prospective study. The effect on final height cannot be proven with certainty in uncontrolled studies. If all available results from clinical trials are combined, a positive correlation between response and dose appears likely.

A nationwide cohort study on Creutzfeldt-Jakob disease among human growth hormone recipients

OBJECTIVE

In 1991, a Dutch patient who had been treated from 1963 to 1969 with human-derived growth hormone died of Creutzfeldt-Jakob disease (CJD). This study was performed to investigate whether among other Dutch human growth hormone recipients there were clinically suspected cases of iatrogenic CJD.

METHODS

In a retrospective cohort study, all patients (n = 564) treated with human-derived growth hormone before May 1985 and recorded in the Dutch National Growth Registry were followed up until January 1995 for a clinical diagnosis of CJD. For this purpose, all human growth hormone recipients were linked to a database of the Foundation for Health Care Information comprising hospital discharges with a clinical diagnosis of iatrogenic CJD. Linkage of the two databases was performed on the basis of date of birth and gender. Subsequently, verification of patient's name and initials of the positively matched pairs took place.

RESULTS

Linkage provided 37 positively matched pairs concerning 29 individual patients. After verification, no name from the hospital discharge records corresponded to the names of the human growth hormone recipients. CONCLUSIONS The follow-up of 564 Dutch human growth hormone recipients, who had been treated with human growth hormone until 1985 did not establish any clinically suspected case of iatrogenic CJD. Future cases, however, can still emerge due to the potentially long incubation period of prion diseases.

Expression of Indian hedgehog, parathyroid hormone-related protein, and their receptors in the postnatal growth plate of the rat: evidence for a locally acting growth restraining feedback loop after birth

A locally acting growth restraining feedback loop has been identified in the murine embryonic growth plate in which the level of parathyroid hormone-related peptide (PTHrP) expression regulates the pace of chondrocyte differentiation. To date, it is largely unknown whether this feedback loop also regulates the pace of chondrocyte differentiation in the growth plate after birth. We therefore characterized the spatio-temporal expression of Indian hedgehog (IHH), PTHrP, and their receptors in the postnatal growth plate from female and male rats of 1, 4, 7, and 12 weeks of age. These stages are representative for early life and puberty in rats. Using semiquantitative reverse-transcription polymerase chain reaction (RT-PCR) on growth plate tissue, IHH and components of its receptor complex, patched (PTC) and smoothened (SMO), PTHrP and the type I PTH/PTHrP receptor messenger RNA (mRNA) were shown at all ages studied irrespective of gender. Using in situ hybridization, IHH, PTHrP, and PTH/PTHrP receptor mRNA were detected in prehypertrophic and hypertrophic chondrocytes in both sexes during development. In addition, especially in the younger age groups, faint expression of PTH/PTHrP receptor mRNA also was shown in stem cells and proliferative chondrocytes. Immunohistochemistry confirmed the observations made with in situ hybridization, by showing the presence of IHH, PTC, PTHrP, and PTH/PTHrP receptor protein in prehypertrophic and hypertrophic chondrocytes. In addition, staining for hedgehog, PTC, and PTHrP also was observed in growth plate stem cells. No differences in staining patterns were observed between the sexes. Furthermore, no mRNA or protein expression of the mentioned factors was detected in the perichondrium. Our data suggest that in contrast to the proposed feedback loop in the early embryonic growth plate, which requires the presence of the perichondrium, a feedback loop in the postnatal growth plate can be confined to the growth plate itself. In fact, two loops might exist: (1) a loop confined to the transition zone and early hypertrophic chondrocytes, which might in part be autocrine and (2) a loop involving the growth plate stem cells.

Continuing positive secular growth change in The Netherlands 1955-1997

Since 1858, an increase of mean stature has been observed in the Netherlands, reflecting the improving nutritional, hygienic, and health status of the population. In this study, stature, weight, and pubertal development of Dutch youth, derived from four consecutive nationwide cross-sectional growth studies during the past 42 y, are compared to assess the size and rate of the secular growth change. Data on length, height, weight, head circumference, sexual maturation, and demographics of 14,500 boys and girls of Dutch origin in the age range 0-20 y were collected in 1996 and 1997. Growth references for height and weight were constructed with a method that summarizes the distribution by three smooth curves representing skewness (L curve), the median (M curve), and coefficient of variation (S curve). The relationship between height and demographic variables was assessed by multivariate analysis. Reference curves for menarche and secondary sex characteristics were estimated by a generalized additive model using a logit transformation. A positive secular growth change has been present in the past 42 y for children, adolescents, and young adults of Dutch origin, although at a slower rate in the last 17 y. Height differences according to region, educational level of child and parents, and family size have remained. In girls, median age at menarche has decreased by 6 mo during the past four decades to 13.15 y. Environmental conditions have been favorable for many decades in the Netherlands, and the positive secular change in height has not yet come to a halt, in contrast to Scandinavian countries. Main contributors to the increase in height may be improved nutrition, child health, and hygiene, and a reduction of family size.

The use of GH as pharmacological agent (minireview)

Growth hormone (GH) has been traditionally used a drug for substitution therapy of GH deficiency, but since the wide availability of biosynthetic GH it has also been used as a pharmacological agent. In this report the presently available data are reviewed.

Body index measurements in 1996-7 compared with 1980

OBJECTIVES

To compare the distribution of body mass index (BMI) in a national representative study in The Netherlands in 1996-7 with that from a study in 1980.

METHODS

Cross sectional data on height, weight, and demographics of 14 500 boys and girls of Dutch origin, aged 0-21 years, were collected from 1996 to 1997. BMI references were derived using the LMS method. The 90th, 50th, and 10th BMI centiles of the 1980 study were used as baseline. Association of demographic variables with BMI-SDS was assessed by ANOVA.

RESULTS

BMI age reference charts were constructed. From 3 years of age onwards 14-22% of the children exceeded the 90th centile of 1980, 52-60% the 50th centile, and 92-95% the 10th centile. BMI was related to region, educational level of parents (negatively) and family size (negatively). The -0.9, +1.1, and +2.3 SD lines in 1996-7 corresponded to the adult cut off points of 20, 25, and 30 kg/m(2) recommended by the World Health Organisation/European childhood obesity group.

CONCLUSION

BMI age references have increased in the past 17 years. Therefore, strategies to prevent obesity in childhood should be a priority in child public health.

Length velocity acceleration at 9 months of age in a representative birth cohort of Dutch infants

According to the ICP (infancy-childhood-puberty) growth model, statural growth can be divided into three partially superimposed components assumed to represent different physiologic mechanisms. This model predicts a sudden acceleration of length velocity (LV) at the onset of the childhood component around 9 months. The existence of such an infancy-childhood growth spurt has not yet been firmly corroborated by epidemiological studies. In the present study length measurements were made at the target ages of 1, 3, 6, 9, 12, 15, 18 and 24 months in a birth cohort of 2034 infants. In order to check whether length growth showed a continuous smooth pattern, different mathematical models were fitted to the individual growth curves. The models included Count and Guo functions, 5th order polynomial and combinations of 5th order polynomial with the logarithmic term of the Count function and the square root term of the Guo function. We showed that in boys and girls there is a small but systematic lack of fit of the mathematical modeling, due to a sudden acceleration of LV around 9 months. In addition there was an increase in variation of attained length at this age. Comparison of unbalanced ANOVA models with and without addition of dummy variables for the target ages confirmed that there was an acceleration around 9 months that, if corrected for, leads to a significantly improved model fit (likelihood ratio test p < 0.0001). In absolute terms of LV, the misfit at 9 months was not greater than 0.5 cm/year on average. We conclude that the results of this study support the existence of a late infancy growth spurt. In our opinion, however, the magnitude of the phenomenon does not legitimate construction and use of discontinuous growth references such as the ICP reference.

Pubertal development and growth after total-body irradiation and bone marrow transplantation for haematological malignancies

Pubertal development after total-body irradiation (TBI) was investigated in 40 children (21 boys) treated with allogeneic bone marrow transplantation (BMT) for haematological malignancies at a mean age of 11.3 years. The mean age at the last visit was 19.0 years. Twenty-five patients (15 boys) were prepubertal at BMT. Data on secondary sexual characteristics, the pituitary-gonadal axis and longitudinal growth were retrospectively collected from the medical records. In boys not receiving additional testicular irradiation (n = 19), penile growth and pubic hair development was normal and all had serum testosterone levels within the adult range. The majority of them, however, had incidental elevations of LH, suggesting minor Leydig cell damage. Testicular volume at last measurement was small (mean: 10.5 ml) and serum FSH levels were elevated in all boys, with normalisation in only one, suggesting severe impairment of reproductive gonadal function. Of the ten girls who received BMT before puberty, six had a spontaneous onset of puberty and menarche; the four other girls needed hormonal substitution therapy. Recovery of gonadal function after cessation of substitution was seen in one girl, who became pregnant but had a spontaneous abortion. Decrease in height SDS was seen in the majority of patients and was positively correlated with male gender and lower age at the time of BMT.

CONCLUSION

Careful monitoring of both gonadal function and growth after bone marrow transplantation and total body irradiation is warranted in order to detect disturbances early and ensure normal pubertal development in children treated for haematological malignancies.

Influence of growth hormone treatment on pubertal timing and pubertal growth in children with idiopathic short stature. Dutch Growth Hormone Working Group

We studied the influence of recombinant human growth hormone (rhGH) on pubertal timing and pubertal growth in children with idiopathic short stature (ISS), and evaluated whether this was different between children with and without intra-uterine growth retardation (IUGR). Twenty-six (18 M, 6 IUGR; 'treated') subjects were treated with rhGH (6-7 days/week, dosage: 14-28 IU/m2 per week [i.e. 0.2-0.3 mg/kg per week]). Fifty-eight subjects (31 M, 9 IUGR; 'controls') were not treated. All subjects attained final height. Prepubertal height gain was significantly larger in the treated children compared to control children (M: 0.66 SDS, 95% confidence interval [CI] 0.41 to 0.92; F. 0.92 SDS, CI 0.58 to 1.26). Pubertal height gain, peak height velocity and duration of puberty were similar for the treated and control subjects. rhGH advanced the age at peak height velocity by 0.7 years (CI 0.3 to 1.0) in boys, and the age at onset of puberty by 1.1 years (CI 0.3 to 1.9) in girls. The gain in final height was 2-3 cm. Age and height SDS at start were the most important predictors for pubertal height gain, total height gain and final height in a multivariate regression analysis. Total height gain of treated subjects with IUGR was less than that of treated subjects without IUGR. In conclusion, rhGH did not affect pubertal growth in children with ISS, and slightly improved their final height. rhGH treatment should be started early to improve height as much as possible before the onset of puberty.

Efficacy of long-term growth hormone treatment in Turner's syndrome. European Study Group

The efficacy of long-term growth hormone treatment and the optimal treatment modalities in Turner's syndrome are still controversial. Studies have shown widely divergent results. While there is still need for results of randomized controlled trials, large uncontrolled trials remain a valuable source of preliminary information. This study of 136 girls with Turner's syndrome (TS) from the European Lilly Turner Study shows that the treatment regimens followed by girls with TS who start GH treatment at a relatively late age (12.9 +/- 2.2 yr) lead at best to a small average gain in final height. Mean gain over initial projected final height was 3.7-4.7 cm, depending on the chosen Turner-specific height-for-age reference data. There was a considerable variation in gains over initial projected final height (range -10.6 to +17.2 cm), which may be partly explained by the existence of good and bad responders. Whether there is a genetic/molecular basis for this and how responsiveness can best be predicted remains an important challenge.

Effects of total-body irradiation on growth, thyroid and pituitary gland in rhesus monkeys

PURPOSE

To investigate the effect of total-body irradiation (TBI) on growth, thyroid and pituitary gland in primates.

METHODS AND MATERIALS

Thirty-seven rhesus monkeys (mean age 3.1+/-0.6 years) received either a low-dose (4-6 Gy) TBI (n = 26) or high-dose (7-12 Gy) TBI (n = 11) and were sacrificed together with 8 age-matched controls after a post-irradiation interval of 5.9+/-1.5 years. Anthropometric data were collected: thyroid and pituitary glands were examined; serum levels of thyroid stimulating hormone (TSH), free thyroxin (FT4), insulin-like growth factor-I (IGF-I) and its binding protein-3 (IGFBP-3) were measured.

RESULTS

Decrease in final height due to irradiation could not be demonstrated. There was a dose-dependent decrease in body weight, ponderal index, skinfold thickness and thyroid weight. The latter was not accompanied by elevation of TSH or decrease in FT4. Structural changes in the thyroid gland were found in 50% of the irradiated animals. Levels of IGF-I and IGFBP-3 did not differ between the dose groups, but the high-dose group had a lower IGF-1/IGFBP-3 ratio.

CONCLUSION

Total body irradiation had a negative effect on body fat. There was no evidence of (compensated) hypothyroidism, but dose-dependent decrease in thyroid weight and changes in follicular structure suggest some effect of TBI on the thyroid gland. The decreased IGF-I/IGFBP-3 ratio in the high-dose group can indicate that the somatotrophic axis was mildly affected by TBI. These results show that TBI can have an effect on the physical build and thyroid gland of primates even in the absence of cytostatic agents or immunosuppressive drugs.

A limited repertoire of mutations of the luteinizing hormone (LH) receptor gene in familial and sporadic patients with male LH-independent precocious puberty

Herein, we report mutation analysis of the LH receptor gene in 17 males with LH-independent precocious puberty, of which 8 were familial and 9 had a negative family history. A total of 7 different mutations (all previously reported) were detected in 12 patients. Among 10 European familial male-limited precocious puberty (FMPP) patients who had a LH receptor gene mutation, none had the Asp578Gly mutation, which is responsible for the vast majority of cases in the U.S. The restricted number of activating mutations of the LH receptor observed in this and other studies of FMPP strongly suggests that an activating phenotype is associated with very specific sites in the receptor protein. Clinical follow-up of the 5 patients who did not have LH receptor mutations shows that such cases most likely do not have true FMPP. LH receptor mutation analysis provides a sensitive tool for distinguishing true FMPP from other causes of early-onset LH-independent puberty in males.

Plasma levels of insulin-like growth factor (IGF)-I, IGF-II and IGF-binding protein-3 in the evaluation of childhood growth hormone deficiency

BACKGROUND

Traditionally, measurement of plasma IGF-I and more recently of IGFBP-3 are used to distinguish GHD from idiopathic short stature in slowly growing children, using a single blood sample. In earlier studies it was claimed that IGFBP-3 was superior to IGF-I, but more recently doubts around this claim have arisen. The role of serum IGF-II has never been studied extensively. On theoretical grounds, it can also be hypothesized that molar ratios of these peptides might be of additional value.

DESIGN

Retrospective, multicentre, cohort study.

PATIENTS

96 children evaluated for short stature.

METHODS

Serum IGF-I, IGF-II, IGFBP-3 and various molar ratios were, after correction for age and sex using SD scores, compared to the maximum serum GH peak after two standard provocation tests using four different methods (t-test, chi2, likelihood ratios and ROC curves). In addition, the correlations between these parameters and the short-term (1 year) and long-term (3 years) response to GH therapy were calculated.

RESULTS

IGF-I performed better than IGFBP-3, but the best results were achieved by the molar ratio IGF-I:IGF-II. However, IGFBP-3 correlated better with the short-term response to GH therapy than IGF-I or the ratios, and none of the parameters investigated was found to be related to the response of long-term GH therapy.

Quality of life of young adults with idiopathic short stature: effect of growth hormone treatment. Dutch Growth Hormone Working Group

The aim of the study was to evaluate whether treatment with recombinant human growth hormone (rhGH) affects the quality of life of young adults who were diagnosed as idiopathic short stature (ISS) during childhood, and whether their quality of life and aspects of the personality are different from normal. Experiences and expectations concerning rhGH treatment of the subjects and their parents were also investigated. Eighty-nine subjects were included into the study: 24 subjects (16M, 8F) were treated with rhGH from childhood, whereas 65 subjects (40M, 25F) were never treated. At the time of the interview all subjects had attained final height [mean (SD) -2.3 (0.9) SDS for Dutch references], and the age of the treated subjects was 20.5 (1.0) y, and 25.7 (3.5) y of the control subjects (p < 0.001). The level of education was similar, but the treated subjects had less often a partner compared to the control subjects (adjusted for age and gender, p < 0.001). The Nottingham Health Profile and Short Form 36 Health Survey showed no difference in general health state between treated and control subjects, and the healthy Dutch age-specific references (norm group). Although 74% of the subjects reported one or more negative events related to their height, and 61% would like to be taller, only 22% and 11% were willing to trade-off at Time Trade-Off and Standard Gamble, respectively. The personality of the subjects, which was measured by the Minnesota Multiphasic Personality Inventory, was not different from the norm group. The satisfaction with the rhGH treatment was high, as it had caused 12 (8) cm and 13 (7) cm gain in final height according to the subjects and parents, respectively. Based on initial predicted adult height (Bayley & Pinneau), this gain was only 3.3 (5.6) cm. We concluded that although the treated subjects had a partner less often when compared to the control subjects, the quality of life of subjects with ISS at adult age is normal and appears not to be affected by rhGH therapy, The treated subjects were very satisfied with the treatment, probably by overestimation of the final height gain.

The role of estrogen in the control of rat osteocyte apoptosis

We have previously shown that estrogen withdrawal by gonadotrophin-releasing hormone analogs (GnRHa) induces osteocyte death via apoptosis in human bone. Although it is likely that the increase in osteocyte death via apoptosis was related to the loss of estrogen, these experiments could not rule out a direct role for the GnRHa. Therefore, in this study, we have used a rat model of ovariectomy (OVX) to determine whether the effect of estrogen withdrawal extends to other species and to clarify the role of estrogen in the maintenance of osteocyte viability. Twelve 9-week-old rats were divided into three treatment groups: sham operated (SHAM) (n = 4), OVX (n = 4), and OVX + estrogen (E2) (25 microg/day) (n = 4). At 3 weeks following the start of treatment, tibial bones were removed. The percentage of osteocytes displaying DNA breaks, using an in situ nick-translation method, was significantly higher in the OVX group compared with the SHAM control in both cortical bone (10.04% vs. 2.31%, respectively; p < 0.0001) and trabecular bone (6.44% vs. 1.58%, respectively; p = 0.003). Addition of estrogen in the OVX animals completely abrogated the increase in osteocyte apoptosis in cortical bone (0.78%) and trabecular bone (1.17%). The percentage of apoptotic osteocytes decreased with increasing distance from the primary/secondary spongiosa interface below the growth plate in the OVX model and the OVX + E2 model. Nuclear morphology and electrophoresis of DNA confirmed the presence of apoptotic cells in the samples. In conclusion, OVX in the rat results in an increase in osteocyte apoptosis as a direct or indirect result of E2 loss. Addition of estrogen in the OVX animals prevents this increase in osteocyte apoptosis. These data confirm an important role for estrogen in the control of osteocyte apoptosis and the maintenance of osteocyte viability. Estrogen deficiency might, through compromising the viability of osteocyte networks, reduce the ability of bone to respond appropriately to loading.

Measuring health-related quality of life in children: the development of the TACQOL parent form

Health-related quality of life (HRQoL), conceptualized as patients' own evaluations of their health status, is an important criterion in evaluation health and health care and in the treatment of individual patients. Until now, few systematic attempts have been made to develop instruments to assess the HRQoL of children using such a conceptualization. This article describes the conceptualization and results of a study aiming to develop such an instrument for children aged 6-15 years using their parents as a proxy. The feasibility and psychometric performance of the instrument were evaluated in a study of 77 patients of the paediatric out-patient clinic of Leiden University Hospital. For each of the a priori-defined domains, a parent form scale could be constructed with satisfactory reliability and moderate correlations with the other scales. Only some of the parents indicating health status problems also signalled negative reactions to these problems. This is, in our view, a strong argument for the distinction between health status and quality of life (QoL). The correlation coefficients between the parent form and a children's questionnaire were low. Overall, the psychometric performance of the TACQOL parent form looks promising, which suggests that this instrument--with some modifications--can indeed be used to assess group differences in HRQoL in children. The results, however, should be replicated in larger samples, currently under study. The relation between parents' proxy reports on the HRQoL of their children and children's self-reports needs further investigation.

The proxy problem: child report versus parent report in health-related quality of life research

This study evaluates the agreement between child and parent reports on children's health-related quality of life (HRQoL) in a representative sample of 1,105 Dutch children (age 8-11 years old). Both children and their parents completed a 56 item questionnaire (TACQOL). The questionnaire contains seven eight-item scales: physical complaints, motor functioning, autonomy, cognitive functioning, social functioning, positive emotions and negative emotions. The Pearson correlations between the child and parent reports were between 0.44 and 0.61 (p < 0.001). The intraclass correlations were between 0.39 and 0.62. On average, the children reported a significantly lower HRQoL than their parents on the physical complaints, motor functioning, autonomy, cognitive functioning and positive emotions scales (paired t-test: p < 0.05). Agreement on all of the scales was related to the magnitude of the HRQoL scores and to some background variables (gender, age, temporary illness and visiting a physician). According to multitrait-multimethod analyses, both the child and parent reports proved to be valid.

De novo mutations of the growth hormone gene: an important cause of congenital isolated growth hormone deficiency?

A family with isolated growth hormone deficiency (IGHD) in two children and their mother is reported. Genetic analysis revealed a heterozygous splice site mutation in intron III of the GH-1 gene. This mutation was de novo in the mother and was transmitted in a dominant way to her offspring.

CONCLUSION

De novo mutations in the GH-1 gene may be an important cause of congenital idiopathic IGHD. As these patients have normal fertility, pointing out this mutation is of great value for appropriate genetic counselling in patients with idiopathic IGHD.

Polymorphic detection of a parthenogenetic maternal and double paternal contribution to a 46,XX/46,XY hermaphrodite

True hermaphroditism in humans usually is associated with a 46,XX karyotype or with mosaicism in which admixtures of cells with an XX and an XY karyotype are seen. However, the mechanisms that cause such mosaicisms are poorly understood. To date, with rare exceptions, analyses of hermaphrodites have been limited mostly to cytogenetic investigations. In this report, we describe a 5-year-old patient with true hermaphroditism and a 46,XX/46,XY karyotype (ratio 38:12) in lymphocytes, suggesting involvement of two fertilization events. Microsatellite DNA polymorphisms distributed throughout the genome were analyzed, to investigate the origin of the cell lines concerned. The results are consistent with double paternal and single maternal genetic contributions. Possible mechanisms that would explain these findings are discussed. The most likely mechanism involves a single haploid ovum dividing parthenogenetically into two haploid ova, followed by double fertilization and fusion of the two zygotes into a single individual, at the early embryonic stage.

Growth hormone therapy with three dosage regimens in children with idiopathic short stature. European Study Group Participating Investigators

OBJECTIVE

In children with idiopathic short stature (ISS) we studied the growth-promoting effect at 4 years of recombinant human growth hormone (rhGH) therapy in three dose regimens and evaluated whether increasing the dosage after the first year could prevent a decline in height velocity (HV).

DESIGN

Included were 223 patients who were treated with subcutaneous administrations of rhGH 6 days per week. They were randomized to three groups: 3 IU/m2 body surface/day, 4.5 IU/m2/day, and 3 IU/m2/day during the first year and 4.5 IU/m2/day thereafter, corresponding with dosages of 0.2 and 0.3 mg/kg body weight/week, respectively. Growth was compared with a standard of 229 untreated children with ISS [ISS standard].

RESULTS

During the first year of treatment HV almost doubled and was higher with 4.5 IU/m2 than with 3 IU/m2. In the second year HV no longer differed among the groups, but increasing the dosage slowed the rate of the fall of HV. During 4 years of therapy the height SD score for age increased by a mean (SD) of 2.5 (1.0) [ISS standards], or 1.2 (0.7) (British standards), bone age increased by 4.8 (1.3) years, and predicted adult height SD score increased by 1.5 (0.7). After 4 years the results of the group with 4.5 IU/m2 were slightly better than those of the other groups. When dropouts were included in the analysis (assuming a stable height SD score after discontinuation of rhGH therapy), height gain was still significant.

CONCLUSIONS

During 4 years of rhGH therapy, growth and final height prognosis improved, slightly more with 4.5 IU/m2 than with 3 IU/m2 or 3 to 4.5 IU/m2. However, bone age advanced on average 4.8 years during this period; therefore, any effect on final height will probably be modest.

[Clinical drug research in children: current international guidelines. Committee for Proprietary Medicinal Products]

Drugs research in children entails a number of problems: medical-ethical, pharmacological (owing to the immaturity of the organs and the growth and development of the child) and financial (because children do not use many drugs). Consequently, children are exposed to insufficiently tested drugs and new therapeutic possibilities are withheld from them. Currently, little clinical drugs research in children is being carried out, but this is about to change. By now, European guidelines have been drawn up for the performance of clinical drugs trials according the 'good clinical practice' standards in children. In the Netherlands, a cooperative body has been set up (the Pediatric Pharmacology Network), which is to promote and coordinate paediatric pharmacological research in according with these guidelines.

Effects of long-term gonadotrophin-releasing hormone analog treatment on growth, growth hormone (GH) secretion, GH receptors, and GH-binding protein in the rat

Long-acting gonadotropin-releasing hormone (GnRH) analogs (GnRH-a) suppress gonadal steroid production and are used in precocious puberty, resulting in an arrest of pubertal development, a slower epiphyseal maturation, and a deceleration of growth, but an increased final height. However, the way that GnRH-a affect growth is not clear. GnRH-a treatment might not only affect gonadal steroid production but might also modulate the GH axis and thereby affect growth. We used a rat model to investigate the long-term effects of prepubertally started GnRH-a treatment (triptorelin) on growth, spontaneous GH secretion, hepatic GH receptors (GHR), and GH-binding protein (GHBP) and compared it with surgical gonadectomy. Triptorelin affected most parameters in the same direction as surgical gonadectomy but to a lesser extent. In females, growth was enhanced by triptorelin, baseline GH secretion was decreased, and hepatic GHR and GHBP were decreased. Apart from these effects on the GH axis, reduction of the direct inhibiting effect of estrogen on growth could be responsible for the triptorelin-induced growth. In males, triptorelin treatment enhanced body weight gain and slightly enhanced gain in length. GH peak amplitude was the only parameter of GH secretion affected and decreased, whereas GHR or GHBP were not affected. This stimulation of weight gain by long-term triptorelin treatment in male rats, which is opposite the effect of surgical gonadectomy, could indicate an interference of GnRH-a in the hormonal regulation of food intake and body weight control. We conclude that triptorelin treatment affected growth and the GH-GHR-GHBP axis in rats, more markedly in females than in males. However, triptorelin was not as effective as surgical gonadectomy.

Growth before and during growth hormone treatment in children operated for craniopharyngioma

Height and weight growth before and during treatment with human growth hormone (hGH) was studied in 46 Dutch patients treated for craniopharyngioma. Weight was expressed as body mass index (BMI, weight/height). At the time of tumor treatment mean +/- SD height standard deviation score (SDS) was -1.22 +/- 1.38 and BMI SDS was 0.56 +/- 1.32. The initial height SDS was inversely related to age (r = -0.38; p < 0.02). Before hGH treatment height SDS decreased to - 1.57 +/- 1.08 (p < 0.05) and BMI SDS increased to 1.54 +/- 1.58 (p < 0.005) during the first year after tumor treatment. Changes in height SDS correlated positively with basal prolactin (PRL) levels (r = 0.46; p < 0.05). Neither tumor localization nor treatment mode was related to changes in height SDS and BMI SDS. Forty patients were treated with hGH, started a median interval of 2.0 years after tumor treatment. At the time of the start of hGH treatment height SDS in these patients was -1.70 +/- 1.13, and BMI SDS was 1.44 +/- 1.79. During treatment with hGH, height SDS increased to -1.05 +/- 1.10 (p < 0.001) in the first, and to -0.80 +/- 1.04 (p < 0.001) in the second year. BMI SDS did not change during hGH therapy. In conclusion, there is a large variation in height SDS and BMI SDS at the time of initial presentation as well as during spontaneous growth after tumor treatment. Spontaneous growth is related to serum PRL concentrations. Treatment with hGH significantly increased height SDS during the first 2 years, whereas BMI SDS did not change.

Longitudinal analysis of growth in children with idiopathic short stature

In this study the growth curves of 229 children (145 boys, 84 girls ) with idiopathic short stature (ISS) were analysed in three ways: (1) we compared the results of longitudinal modelling by means of Karlberg's ICP model with those of a cross-sectional analysis; (2) we studied to what extent an individual changes his/her height standard deviation score (SDS) position during childhood; and (3) we constructed height velocity curves for children with ISS using Cole's LMS method, and compared these with the British references. During childhood the difference between the average longitudinal and the cross-sectional height curves was less than 1 cm and the spread was almost identical. The average change in height SDS during childhood was not different from zero, indicating that in general growth of children with ISS was well canalized. The individual change in height SDS position during childhood was within 0.6 SDS for a follow-up of 1 year, increasing to 1.9 SDS for a follow-up of 7 years. During childhood mean height velocity was about 1 cm/year lower than that of the British reference. With respect to the pubertal growth spurt the maximum height velocity took place 1 year later, and was 0.6 cm/year lower than the British reference in boys as well as girls. We conclude that spontaneous growth of children with ISS adequately described by a cross-sectional curve.

Reference values for height, height velocity and weight in Turner's syndrome. Swedish Study Group for GH treatment

As Northern Europeans are currently the tallest people in the world, specific growth charts for girls with Turner's Syndrome from this area are needed. Based on height and weight measurements from 598 girls with Turner's Syndrome (372 from the Netherlands, 108 from Denmark, 118 from Sweden) not treated with growth-promoting substances and without signs of spontaneous puberty, we constructed growth charts for height-for-age, height-velocity-for-age, weight-for-age, weight-for-height and Body Mass Index for age. Reference tables and regression equations for mean and standard deviation are provided allowing calculation of Standard Deviation Scores. The height and height velocity curves show a low birth length, gradual deviation from the normal percentile curves without pubertal growth spurt, and a prolonged growth until the early 20s. Mean adult height was 146.9 +/- 7.8 cm. Mean weight-for-age was lower than in normal reference children but height-adjusted weight was higher, except in infancy and early childhood. Further studies are required on the factors influencing the weight-height relationship in Turner's Syndrome.

Growth response and levels of growth factors after two years growth hormone treatment are similar for a once and twice daily injection regimen in girls with Turner syndrome. (Dutch Working Group on Growth Hormone)

GH is known to improve height velocity in girls with Turner syndrome (TS) but the optimal dosage regimen has yet to be defined.

OBJECTIVE

We attempted to improve the growth response by trying to mimic normal pulsatile GH secretion more closely.

DESIGN

In a 2-year study the effect of fractionated twice daily (BID) was compared with once daily (OD) s.c. injections of a total GH dose of 6 IU/m2/day. BID injections were administered as two-thirds at bedtime and one-third in the morning. The subjects concurrently received low dose ethinyl oestradiol (0.05 mg/kg/day, orally).

SUBJECTS

Nineteen girls with TS aged 11 years or over, who were previously involved in a 10-week GH cross-over study.

MEASUREMENTS

Height and bone age were evaluated in relation to untreated Turner reference data. Final height (FH) was predicted using the Bayley and Pinneau (BP) method, the modified index of Potential Height (mIPHRUS), and a recently developed Turner-specific method (PTSRUS) based on regression coefficients for height (H), chronological age (CA) and bone age (BA). Plasma levels of GH, GHBP, IGF-1, and IGFBP-3 were determined by RIA.

RESULTS

After 2 years treatment the growth response expressed as HV, HVSDS, the change in HSDSCA, the gain in height over estimated untreated values and in FH prediction all showed significant improvements. Although mean values tended to be higher with OD injections, significant differences between groups were not found. Bone maturation was similar between groups and compared with untreated estimated values. Independent of treatment group, the change in HSDSCA after 2 years of GH treatment was related negatively to the baseline CA and HSDSCA, and positively to BA delay at baseline. After 18 months of GH treatment the significant decrease in GHBP plasma levels observed after 6 months was no longer significant. In contrast, IGF-1 and IGFBP-3 plasma levels and the IGF-1 to IGFBP-3 ratio increased significantly during 18 months GH therapy. None of these growth related factors showed a difference between groups in their 18 months change. Relevant side-effects were not observed during the first 2 years of GH treatment.

CONCLUSIONS

The present growth data are in conformity with the data of the earlier 24-hour GH profiles. The growth response and plasma levels of growth related factors after 2 years GH on a total dose of 6 IU/m2/day in combination with low-dose oestrogens were not significantly different between the once daily and the twice daily GH injection regimen.

[Micropenis in children: etiology, diagnosis and therapy]

The term 'micropenis' is applied if the measured penile length is more than 2.5 standard deviations below the mean for the age; in neonates born at term this means a penile length of less than 2 cm. Micropenis is the consequence of a defect which develops after the 14th week of pregnancy. The cause may be hormonal (hypothalamo-hypophysial (hypogonadotropic hypogonadism), testicular (hypergonadotropic hypogonadism) or end organ resistance), but also iatrogenic (medication during the pregnancy). In addition, micropenis occurs as a part of a number of syndromes. The diagnostic investigation comprises history-taking, physical examination, specific hormonal testing and, if considered necessary, chromosomal and imaging examinations. In the treatment of micropenis, a trial treatment with testosterone plays an important part.

Anthropometry and body composition in children

Changes in body fat, fat-free mass and extracellular water occur in many disorders, and during normal growth in children. Thus, body composition is an increasingly important measurement in paediatric clinical practice, and is used for diagnostic purposes, for decisions for treatment and for monitoring improvement. A number of different methods exist for determining body composition in children; however, their use is complicated by the absence of a gold standard and the lack of validity data in children both with and without growth disorders. In this report, validity and usefulness are compared among anthropometric methods and weighted against other techniques used in children. Recent recommendations of a number of expert committees are discussed.

Yearly stepwise increments of the growth hormone dose results in a better growth response after four years in girls with Turner syndrome. Dutch Working Group on Growth Hormone

To optimize the growth promoting effect of growth hormone (GH), 65 previously untreated girls with Turner syndrome (TS), chronological age (CA) 2-11 yr, were randomized into 3 dosage regimen groups: A, B, and C, with a daily recombinant-human GH dose during 4 study years of 4-4-4-4, 4-6-6-6, and 4-6-8-8 IU/m2 b.s. The first GH dosage increase in groups B and C resulted in a significantly higher mean height velocity (HV) compared with constant dose group A. During the third year, when the dose was raised again only in group C, mean HV was significantly higher in groups B and C than in group A, and in group C compared with group B. In year 4 only group C mean HV remained significantly higher than group A. The pattern of change in HSDSCA (Dutch-Swedish-Danish Turner references) was identical; however, in year 4 mean delta HSDSCA in group B also remained significantly higher than group A. After 4 yr GH treatment, the following was determined. 1) The mean delta HSDSCA was significantly higher for groups B and C compared with group A, but not significantly different between groups B and C. 2) Although significantly higher compared with estimated values for untreated Dutch girls with TS, bone maturation of the GH treated girls was not significantly different between groups. 3) It was positively related with the degree of bone age (BA) retardation at start of study and negatively with baseline CA. 4) Both the modified Index of Potential Height (mIPHRUS) and a recently developed Turner-specific final height (FH) prediction method (PTSRUS), based on regression coefficients for H, CA, and bone age, showed significant increases in mean FH prediction, without significant differences between groups. PTSRUS values were markedly higher than the mIPHRUS values. Dose dependency could be shown for the area under the curve (AUC) for GH, but delta HSDSCA was not linearly related with AUC. Baseline GH binding protein (BP) levels were in 84% of the cases within the normal age range; the decrease in mean levels after 6 months GH was not significant. Mean insulin-like growth factor I (IGF-I) and IGFBP-3 plasma levels increased significantly, without significant differences between groups. delta HSDSCA during GH was dependent on IGF-I plasma levels at baseline and during the study period, beta-0.002 and beta-0.0004. Thus, a stepwise GH-dosing approach reduced the "waning" effect of the growth response after 4 yr treatment without undue bone maturation. FH prediction was not significantly different between treatment groups. Irrespective of the GH dose used, initiation of GH treatment at a younger age was beneficial after 4 yr GH when expressed as actual cm gained or as gain in FH prediction, but was not statistically significant when expressed as delta HSDSCA over the study period.

Final height and hormonal function after bone marrow transplantation in children

AIM

To analyze final height and hormonal function in long-term survivors of bone marrow transplantation (BMT).

PATIENTS

Group 1 consisted of 16 patients (10 boys) with a hematologic malignancy, mostly leukemia, conditioned for BMT with total body irradiation (TBI), 7.5 to 12 Gy, and cyclophosphamide. Group 2 consisted of 14 patients (9 boys) with severe aplastic anemia, conditioned with chemotherapy only.

RESULTS

In group 1, patients achieved a reduced final height after BMT. The difference between the height standard deviation score (SDS) at BMT and the height SDS at final height was -1.96 (0.82) SDS in boys and -0.92 (0.71) SDS in girls (p = 0.0001, and p = 0.02 respectively). Final height was also lower than target height (boys, p = 0.01; girls, p = 0.03). Prepubertal growth in the first 3 years after BMT was normal but pubertal height gain was decreased. The patients in group 2 achieved normal height. Thyroid function and adrenal function were normal in all patients, and no growth hormone deficiency was detected. Serum follicle-stimulating hormone values after BMT were increased in all group 1 patients, with return to normal in two patients. Serum luteinizing hormone values were increased in all group 1 girls, with recovery in one girl. Normal serum luteinizing hormone values and spontaneous puberty were found in all group 1 boys. In group 2, disturbances in gonadotropins were seen only in three boys and two girls.

CONCLUSION

In patients treated in childhood with BMT after chemotherapy and TBI with 7.5 Gy or more, final height is compromised because of blunted growth in puberty. Patients who had not received TBI suffered no height loss. In the majority of patients, the combination of chemotherapy and TBI also resulted in irreversible disturbances of gonadal function.

Growth curves of Dutch children with Down's syndrome

Two thousand and forty-five observations on height and weight were collected from 295 healthy Dutch children with Down's syndrome. In a cross-sectional analysis, means and standard deviations were calculated per age-class, and subsequently smoothed, resulting in age references between 0 and 20 years. Each child contributed only once in every age class. In a subgroup in whom more than four measurements were available before puberty, quadratic regression functions were determined on the basis of the full data set, as well as for individual children separately (54 boys and 25 girls). The average coefficients of the individual regression functions were almost identical to the coefficients of the regression line through all data, indicating that the reference curve for the mean height based on cross-sectional analysis adequately represents longitudinal growth during childhood. Dutch children with Down's syndrome are taller than their US peers (P50 equals P75) but more than 2 SD shorter than normal Dutch children. Above the age of 10 years, the mean weight for height is above the P90 of normal children.