Longitudinal study of hormonal and physical development in young twins.

CONTEXT AND OBJECTIVE: Information on the correlation of normative reproductive hormone levels with physical development (Tanner stages) during puberty and on the influences of genes and environment on variation in these hormones and Tanner stages is limited. DESIGN, SETTING, AND PARTICIPANTS: One hundred twelve healthy 9-year-old twin pairs (n = 224) took part in a longitudinal study, of which 89 pairs participated again at age 12 years (n = 178). MAIN OUTCOME MEASURES: Morning urinary LH, FSH, estradiol, and salivary testosterone levels, determined by competitive immunoassays, were measured. Tanner stages were determined through physical examination. RESULTS: Over the 3-year interval, all hormone levels showed a 2- to 9-fold increase. LH and FSH at age 9 years predicted sex-specific Tanner stages at age 12 years in both boys and girls. Most of the associations between hormone levels at age 9 years and physical development at 12 years were explained by genetic influences. FSH in 9-year-old boys correlated with all hormone levels and Tanner stages at age 12 years. Moderate to high heritability estimates were found for hormone levels at both ages and in both sexes. In girls a shift from environmental (age 9 years) to genetic influences (age 12 years) was found for estradiol and pubic hair development, and for breast development a shift in the opposite direction was seen. CONCLUSIONS: During development LH and FSH (and testosterone in boys) levels predict secondary sexual characteristics in boys and girls 3 years later. These correlations are largely due to genes that are involved in both early pubertal hormone levels and subsequent physical development.

Association between impulsivity, reward responsiveness and body mass index in children.

BACKGROUND: Childhood obesity is a major health problem. An association between children's body mass index (BMI) and overeating has been established, but mechanisms leading to overeating are poorly understood. The personality characteristics impulsivity and reward responsiveness may be involved in the tendency to overeat. Impulsivity might relate to overeating through poor inhibition of food intake; reward responsiveness through the rewarding value of food. OBJECTIVE: This study aimed to reveal the relationships between impulsivity, reward responsiveness, overeating and BMI in a sample of 346 Dutch children aged 6-13 years. The BMI distribution in the sample was representative of the BMI distribution in the Dutch pediatric population. METHODS: Impulsivity and reward responsiveness were measured with the Dutch version of the parent-report Sensitivity to Punishment and Sensitivity to Reward Questionnaire for children. Overeating was assessed with the Dutch translation of the parent-report Children's Eating Behaviour Questionnaire. RESULTS: Overeating, impulsivity and reward responsiveness were significantly associated with childhood BMI. Mediation analysis revealed that impulsivity and reward responsiveness equally and significantly predicted BMI indirectly through overeating. CONCLUSIONS: The personality characteristics impulsivity and reward responsiveness predict childhood BMI indirectly through overeating. This suggests that these personality characteristics are risk factors for obesity.

[Undescended testis: current views and advice for treatment]. / De niet-scrotale testis: huidige inzichten en advies voor behandeling.

--Undescended testis (UDT) is one of the most common urogenital abnormalities in boys. --UDT is defined as a testis which cannot be brought into a stable scrotal position. --At present, congenital and acquired forms of UDT are recognised. Congenital UDT is defined as a UDT which has never descended from birth. Acquired UDT is defined as a UDT which has been fully descended in the past. --Congenital UDT should be treated surgically between 6 to 12 months of age. --The treatment of acquired UDT is still disputed. As yet, awaiting spontaneous descent at early puberty seems to be the most rational treatment. --In the Netherlands, the high number of late orchidopexies is due to surgery for acquired UDT. To reduce this high number, the guidelines of the first development conference on 'non-scrotal testis' dating back to 1986 should be revised on several points.

[A girl with Cushing's syndrome due to primary pigmented nodular adrenocortical disease]. / Een meisje met het syndroom van Cushing door primaire gepigmenteerde nodulaire adrenocorticale ziekte.

A 12.5-year-old girl with diabetes mellitus type 1 presented with stunted growth and an increase in body weight. Also, her blood-sugar levels were difficult to manage. An adrenocorticotropin-(ACTH)-independent form of Cushing's syndrome was diagnosed. During the dexamethasone-suppression test, a paradoxical increase in urinary-free cortisol excretion was observed, which is a clear indication of primary pigmented nodular adrenocortical disease (PPNAD). The treatment for patients with PPNAD is bilateral adrenalectomy and hormone substitution. PPNAD may be part of the Carney complex, an autosomal dominant multiple neoplasia syndrome. Screening of family members is mandatory. Further investigation for mutations in the gene encoding the regulatory subunit 1A of the protein kinase A (PRKAR1A) may be helpful.

Gonadotropin releasing hormone analogue therapy in children with isolated growth hormone deficiency: final height benefit from postponing puberty?

Although growth hormone (GH) treatment has improved final height prognosis in children with GH deficiency (GHD), adult heights are still disappointing. Final height could be improved by increasing the duration of puberty and in this way increasing total pubertal height gain. Many studies have been published on the effect of gonadal suppression, mostly by gonadotropin releasing hormone (GnRH) analogues, on final height in children with GHD. Because of the different methodologies used in these studies, results are difficult to compare. Both positive and marginal effects on final height have been reported; however, patient numbers are limited. Children with GHD who start puberty at a relatively young age and who have a poor predicted adult height, can benefit from the addition of GnRH analogues. From previous studies, we might conclude that when there is a positive effect, height benefit is marginal. However, additional prospective, randomized controlled trials are needed to further elucidate whether delaying puberty is indicated in children with GHD to improve final height.

[From gene to disease; hypogonatrophic hypogonadism and anosmia: Kallmann's syndrome]. / Van gen naar ziekte; hypogonadotroop hypogonadisme en anosmie: het Kallmann-syndroom.

Kallmann's syndrome is a genetic condition characterised by hypogonadotrophic hypogonadism and anosmia; additional neurological and non-neurological symptoms may also occur depending on the specific mode of inheritance. Mode of inheritance can be X-linked (KAL-1), autosomal dominant (KAL-2) or autosomal recessive (KAL-3), although unrelated sporadic cases occur more frequently. The gene responsible for the X-linked form, namely KAL-1, and its encoded protein anosmin-1 have been identified for some time. Very recently the gene responsible for the autosomal dominant form was also identified. KAL-2 is caused by loss-of-function mutations in the gene encoding fibroblast growth-factor receptor-1 (FGFR1).

Individuals at increased coronary heart disease risk are characterized by an impaired microvascular function in skin.

BACKGROUND: To investigate whether microvascular function in skin is a valid model to study the relationships between cardiovascular risk factors and microvascular function, we investigated skin microvascular function in individuals with increased coronary heart disease (CHD) risk. MATERIALS AND METHODS: Forty-six healthy White individuals aged 30-70 years were studied. Coronary heart disease risk was assessed with the use of the CHD risk score according to the Framingham Heart Study, which is based on the risk factors age, blood pressure, cigarette smoking, total cholesterol, HDL cholesterol and diabetes. Endothelium-dependent and -independent vasodilation in skin were evaluated with laser Doppler after iontophoresis of acetylcholine and sodium nitroprusside. Videomicroscopy was used to measure recruitment of skin capillaries after arterial occlusion. RESULTS: Coronary heart disease risk score (i.e. the 10-year probability of CHD) varied from 1-37%. Microvascular function decreased with increasing quartiles of CHD risk (for acetylcholine-mediated vasodilation: 687, 585, 420 and 326%, P = 0.002; for nitroprusside-mediated vasodilation: 776, 582, 513 and 366%, P = 0.02; for capillary recruitment: 49.9, 44.6, 27.2 and 26.7%, P = 0.001). These trends were similar in men and women (P for interaction > 0.2) and independent of body mass index. CONCLUSIONS: Increased CHD risk is associated with an impaired endothelium-dependent vasodilatation and capillary recruitment in skin, suggesting that microvascular function in skin is a valid model to study the relationships between cardiovascular risk factors and microvascular function.

Quality of life of growth hormone (GH) deficient young adults during discontinuation and restart of GH therapy.

The present study evaluates the effects of one year of discontinuation and one year of growth hormone (GH) treatment on quality of life (QoL) in young adults with childhood-onset growth hormone deficiency (CO-GHD). Twenty-two subjects (14 males, 8 females; 11 isolated growth hormone deficient [IGHD], 11 multiple pituitary hormone deficient [MPHD]), aged between 15 and 22 years, on ongoing GH treatment were assessed during one year of discontinuation. Thereafter, 9 of these patients, who were found to be still GH deficient (GHD), added by 11 newly recruited GHD patients who also were not treated in the preceding year (in total 10 males and 10 females, aged between 17 and 27, 5 IGHD, 15 MPHD), restarted GH treatment for one year. During discontinuation and restart of GH treatment somatic and psychological assessments took place every 6 months. In the first 6 months of the GH discontinuation period insulin-like growth factor I (IGF-I) level significantly declined whereas no further decrease in IGF-I was seen after month 6. The number of psychological complaints and depression increased only during the first 6 months of discontinuation. Across the 12-month of discontinuation tension increased in MPHD and decreased in IGHD patients. Only in the first 6 months of GH treatment IGF-I level increased, anxiety decreased and QoL improved. Depression scores tended to decrease across the 12 month treatment period. During the 2-year discontinuation and treatment period intra-subject IGF-I level was negatively correlated with depression, fatigue, tension and anxiety and positively with vigor and memory. At the end of the treatment period all psychometric parameters were similar or even improved compared to those at the start of the discontinuation period. It is concluded that one year discontinuation of GH treatment leads to a decrease in QoL within 6 months which effect is counteracted within 6 months after restart of GH treatment.

Body composition in infants with chronic lung disease after treatment with dexamethasone.

UNLABELLED: The aim of this study was to study the effect of chronic lung disease (CLD) and dexamethasone treatment on body composition in preterm infants (birthweight < 1500 g). In addition, anthropometric measurement of body composition were compared with dual-energy X-ray absorptiometry (DXA). Fourteen preterm infants with CLD and a comparison group of 18 preterm infants were studied until 3 mo corrected age. CLD infants received approximately 20 kcal kg-1 per day extra nutritional intake during dexamethasone treatment until term. At term no differences were found between CLD and no CLD infants for percentage bone mass (1.4 +/- 0.2 vs 1.4 +/- 0.1%), fat mass (18.7 +/- 4.5 vs 17.4 +/- 3.5%), lean body mass (79.9 +/- 4.6 vs 81.2 +/- 3.5%) or bone mineral density (0.15 +/- 0.02 vs 0.15 +/- 0.01%). At 3 mo corrected age both groups were also similar for bone mass (1.6 +/- 0.1 vs 1.6 +/- 0.2%), fat mass (22.6 +/- 5.5 vs 24.5 +/- 5.7%), lean body mass (75.8 +/- 5.7 vs 74.0 +/- 5.8%) and bone mineral density (0.20 +/- 0.02 vs 0.20 +/- 0.01%). All anthropometric measurements showed a high correlation with body composition. However, calculated fat mass was 56.7 +/- 8.8% lower than fat mass measured with DXA. CONCLUSION: Body composition at term and 3 mo corrected age in preterm infants treated with dexamethasone for CLD, who received extra caloric intake until term, did not differ from that in preterm infants without CLD.

Bone metabolism markers and bone mass in healthy pubertal boys and girls.

OBJECTIVE: During puberty, bone growth and mineralization as well as bone turnover increase dramatically. The relation between height velocity and bone turnover is already known, but there are few studies in which both bone metabolism markers and bone mass throughout puberty have been measured. DESIGN: Semi-longitudinal study. In 155 healthy boys (12.0 +/- 1.5 years; range 8.8-15.7 years) and 151 healthy girls (11.2 +/- 1.6 years; range 8.2-14.0 years) markers of bone formation and bone resorption were measured as well as sex steroids, IGF-1 and IGF-BP3, together with bone mineral content (BMC) and bone mineral density (BMD) of the lumbar spine, femur and total body during puberty. All bone measurements were repeated after 1 year. RESULTS: BMC and BMD increased throughout puberty in both sexes. Bone turnover markers increased significantly until maximum values were reached at stage G4 in boys and stage B3 in girls. Height velocity (HV) had a similar changing pattern. Sex steroids and IGF-1 increased and reached adult values at pubertal stage 4. The correlations between bone metabolism markers and BMC were highly significant in boys, while correlations between bone metabolism markers and the increase in BMC over 1 year were significant in both sexes, as was observed for the correlations with HV. CONCLUSIONS: Our data suggest that bone metabolism markers are good predictors of bone mass in boys and of bone mass increase in both sexes. In early puberty, sex steroids stimulate the pubertal growth spurt in conjunction with GH and IGF-1. The fast increase in height gives rise to an increase in bone turnover and bone mineral apposition. It is known that at the end of puberty high levels of oestradiol inhibit chondrocyte proliferation. This leads to a decline in height velocity and bone turnover. Bone mass still increases under the influence of sex steroids and IGF-1. The data in our study confirm previous reports that markers of bone turnover relate positively to height velocity.

[Once growth hormone, always growth hormone? Transition from growth hormone therapy in childhood to adulthood]. / Eenmaal groeihormoon, altijd groeihormoon? De transitie van groeihormoonbehandeling van kind naar volwassene.

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.

Are POMC neurons targets for sex steroids in the arcuate nucleus of the rat?

Testosterone alters the expression of proopiomelanocortin (POMC) mRNA in the neurons of the arcuate nucleus. While observations suggest that both estrogen and androgen receptors (AR) can mediate this action, only a negligible number of POMC neurons has previously been shown to contain estrogen receptor (ER)-alpha. To determine whether the putative action of testosterone is mediated via ER-beta or AR we double immuno- labeled hypothalamic sections from colchicine-pretreated male rats. Only few cells were immunostained for ER-beta and they were never found to co-localize POMC. In spite of the overlap in the anatomical distribution, only 3% of POMC cells appeared to contain AR. These results suggest that sex steroids have an indirect effect on most POMC neurons.

Multiple pituitary hormone deficiency: management of puberty for optimal auxological results.

The overview in this paper focuses on ways of achieving optimal auxological results in puberty, principally in idiopathic and congenital multiple pituitary hormone deficiency (MPHD), suggested by the co-authors. We agreed that diagnosing gonadotrophin insufficiency/deficiency is difficult in young children and should be repeated in late prepuberty, but a firm diagnosis of MPHD helps avoid endocrine re-testing at the end of growth. The hypothalamic-pituitary axis must be reassessed periodically in evolving endocrinopathies, though current practice varies widely. Optimum age to induce puberty is 11-12 years in girls and 13-14 boys, and sex steroids are the preferred agents. Short-course testosterone to increase micropenis size is advantageous, but inducing early testicular maturation is not known to improve later fertility. There is also little evidence for increasing the dose of GH during puberty, though therapy should continue to final height, and possibly until peak bone mass is achieved. Delaying puberty is an option in septo-optic dysplasia, and minimising the dose of hydrocortisone is crucial in treating ACTH/cortisol insufficiency. Many unresolved questions remain in this difficult area.

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.

Glucocorticoids and lung development in the fetus and preterm infant.

During the final prenatal period of fetal lung development in humans, important maturational processes occur, including the production of surfactant necessary to decrease surface tension at the air-liquid interface of the alveoli. During early gestation, the glucocorticoid receptor is expressed in the fetal lung, and glucocorticoids stimulate the production of surfactant-associated proteins and increase phospholipid synthesis by enhancing the activity of phosphatidylcholine. Other glucocorticoid-induced effects may include stimulation of cell maturation and differentiation, inhibition of DNA synthesis, changes in interstitial tissue components, stimulation of antioxidant enzymes, and regulation of pulmonary fluid metabolism. Recently, it was suggested that glucocorticoids are also important in postnatal pulmonary development, and may be related to the development of neonatal lung disease in preterm infants. Surfactant deficiency that can be prevented by antenatal corticosteroid treatment causes infant respiratory distress syndrome and requires mechanical ventilation. Ventilation by itself or in combination with high levels of oxygen, fluid overload, pulmonary infections, sepsis, and air leak syndrome causes an acute pulmonary inflammatory reaction that may result in chronic lung disease or bronchopulmonary dysplasia. Glucocorticoids are effective in the treatment of chronic lung disease of prematurity and regulate the inflammatory response by the interaction with transcription factors such as nuclear factor kappaB and activated protein 1. Indeed, inflammatory cells and the levels of chemokines and cytokines in bronchoalveolar fluid decrease after dexamethasone treatment. However, treatment of fetuses and preterm infants with repeated and/or high doses of corticosteroids may have considerable long-term side effects on somatic, brain, and lung growth. The difficult balance between short-term gain and the possible long-term side effects of glucocorticoids in preterms remains a difficult issue.

Intrauterine growth retardation and puberty in girls.

Some, albeit not all studies on the relationship between intrauterine growth retardation (IUGR) and female pubertal development have found an earlier and rapidly progressing puberty as well as concomitant disorders of related functional systems such as polycystic ovary syndrome and short stature. These pubertal changes are part of a growing list of IUGR-related diseases, which includes non-insulin dependent diabetes mellitus and coronary heart disease. A pulsatile release of gonadotropin releasing hormone is thought to be a conditio-sinne-qua-non for the initiation of puberty. In the absence of prospective studies on gonadotropin releasing hormone pulse patterns in IUGR-children other markers of pubertal development such as age at menarche have been deployed. From these studies it is not clear, however, whether the findings of an earlier onset of puberty in IUGR-girls merely reflect a more rapid progression of puberty. Both the role for IUGR and the mechanisms behind the onset of puberty are still elusive. Assuming a connection between IUGR and pubertal development, parallels can be drawn between hypotheses on the longterm consequences of IUGR and hypotheses on the initiation of puberty. For example, the somatometer concept proposes a role for fat mass in the initiation of puberty, which is compatible with the hypothesis on non-skeletal catch-up growth after IUGR. The debate on the origins of puberty and the role of IUGR mainly focuses on nature and nurture. Judgmentally, studies in mono- and dizygotic twins discordant for birth weight may be of particular help.

Hormonal determinants of pubertal growth.

Pubertal growth results from increased sex steroid and growth hormone (GH) secretion. Estrogens appear to play an important role in the regulation of pubertal growth in both girls and boys. In girls, however, estrogens cannot be the only sex steroids responsible for pubertal growth, as exogenous estrogens do not initiate a complete growth spurt. We therefore investigated the levels of the different sex steroids and GH, and related them to pubertal growth. In addition, we studied the process of bone maturation and mineralization during this period. Levels of both estrogens and androgens were found to increase at the start of the female pubertal growth spurt, and it was demonstrated that height velocity is related to levels of GH, estradiol and androstenedione, but not dehydroepiandrosterone sulfate. In boys, GH, testosterone and estradiol increased at the time of peak height velocity. Bone mineralization increased as puberty began, and was associated with the increase in height velocity. Osteocalcin, a marker of bone formation, declined when height velocity decreased, although bone maturation progressed at a steady rate. We conclude, therefore, that in girls, the concerted actions of estradiol, GH and androstenedione play a role in the pubertal growth spurt, whereas in boys this role is fulfilled by testosterone, GH and estradiol. During puberty, an advanced rate of bone maturation with respect to cross-sectional standards is a physiological phenomenon.

Final height after gonadotrophin releasing hormone agonist treatment for central precocious puberty: the Dutch experience.

Final height (FH) data of 96 children (87 girls) treated with GnRH agonist for central precocious puberty were studied. In girls mean FH exceeded initial height prediction by 7.4 (5.7) cm (p < 0.001); FH was significantly lower than target height, but still in the genetic target range. When treatment started < 6 years of age, height gain was significantly higher than when started > 8 years of age. Bone age (BA) and chronological age (CA) at start of treatment, as well as BA advance at cessation of treatment, were the most important variables influencing height gain in multiple regression analysis. BA advance at start of treatment was most important in simple correlation. In girls, GnRHa treatment seems to restore FH into the target range. A younger age and advanced bone age at start of treatment are associated with more height gain from GnRHa treatment.

Bone mineral density and markers of bone turnover in young adult survivors of childhood lymphoblastic leukaemia.

OBJECTIVE: In order to determine if a serious disease like childhood acute lymphoblastic leukaemia (ALL) and the treatment necessary to cure the patients has long term effects on bone mass, we assessed bone mineral density (BMD) and several parameters involved in bone formation in a group of young adult survivors of ALL. DESIGN AND PATIENTS: Fourteen male and ten female survivors, treated for ALL in childhood, were cross-sectionally studied, at a mean age of 25.1 years (range 20.1-34.9). All patients, except for two, had received cranial irradiation as part of their treatment (mean radiation dose 2460 cGy). MEASUREMENTS: Height and weight were measured. Bone mineral density (BMD) was assessed using dual energy X-ray absorptiometry in the lumbar spine, femoral neck, femoral trochanter and at 1/3 distal and ultradistal in the radius. Early morning serum levels of LH, FSH, oestradiol or testosterone, IGF-1 and IGF-BP3 were determined as well as several specific markers of bone turnover. RESULTS: Mean height, expressed as standard deviation score (SDS) was -1.12, significantly reduced. BMD in the lumbar spine, femoral neck and at 1/3 distal and ultradistal in the radius, was significantly lower compared to the reference population (P < 0.05). No correlation was found between the BMD values and the cumulative dose of administered cytotoxic drugs, the age at diagnosis of ALL or the duration of follow-up. Mean IGF-1 and IGF-BP3 SDS-scores were -1.24 and -0.78 respectively, significantly reduced. GH stimulation tests performed in a subgroup of 9 patients showed an insufficient peak GH response in at least one test in all tested patients. The values of LH, FSH oestradiol or testosterone were within the normal adult range. Serum markers of bone formation and bone resorption were in the normal range, indicating that bone turnover was normal at the time of the study. CONCLUSIONS: Bone development in patients cured of acute lymphoblastic leukaemia is disturbed, resulting in a significantly reduced bone mineral density. Impaired growth hormone activity, as a long term effect of cranial irradiation, may be one of the underlying causes as well as the illness itself and the administered cytotoxic drugs. Since a reduced bone mineral density predispose patients to osteoporosis, intervention in order to improve bone mass should be considered.

Growth parameters in children with retinoblastoma.

The purpose of this study was to compare growth parameters of retinoblastoma patients with siblings and the normal Dutch population. Height, weight, head circumference and sitting height were measured in 67 patients and 63 controls. Target height was calculated based on the parental height of retinoblastoma patients. Standard deviation scores and population-based percentiles were calculated and used for statistical analysis. Retinoblastoma patients had larger head circumferences than the Dutch population and their siblings, and their weight was also higher than the Dutch population. Height and target height showed no differences from the Dutch population. Retinoblastoma patients had a greater sitting height than the Dutch population. Sample numbers were too small to reach statistical significance when comparing the sitting height of retinoblastoma patients with their siblings. No obvious explanations are available for these differences.