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Background/aims: The beneficial effects of growth hormone (GH) therapy on statural growth in children are well established, but the effects on skeletal maturation are less clear. The progression of bone age (BA) was therefore studied during the first year of GH treatment in pre-pubertal children with idiopathic GH deficiency (GHD), Turner syndrome (TS) or idiopathic short stature (ISS), and in short pre-pubertal children born small for gestational age (SGA)., Methods: Cross-sectional data on 2,209 short children with idiopathic GHD, 694 with TS, 569 with ISS and 153 with SGA were analysed. Longitudinal data were also analysed from 308 children with idiopathic GHD, 99 with TS, 57 with ISS and 29 with SGA. All patients included in the study were enrolled in KIGS (Pfizer International Growth Database) and were being treated with recombinant human GH (Genotropin). BA was assessed using the Greulich and Pyle method at baseline and after 1 year of GH therapy., Results: In all groups of patients the mean progression of BA was 1 year during the year of GH therapy, although there was considerable individual variation. Progression of BA was not correlated with chronological age, BA, height SD score (SDS) or body mass index SDS at the onset of GH therapy. There was also no consistent effect of the GH dose on BA progression., Conclusion: Progression of BA appears to be normal in patients receiving GH in these diagnostic groups, at least over the first year of treatment in pre-puberty., (Copyright 2005 S. Karger AG, Basel.)

Although recombinant techniques have enabled the production of limitless amounts of human growth hormone (GH), and clinical methods for diagnosis and treatment have been greatly enhanced, the mean final heights of children with idiopathic GH deficiency (IGHD) treated with GH remain in the range of -1.3 standard deviation scores (SDS) below normal height. One of the methods used to increase height outcomes is to delay the onset and progression of puberty to allow for a longer 'pre-pubertal' growth phase. We reviewed the KIGS (Pharmacia International Growth Database) data of patients with IGHD who had been treated with gonadotropin-releasing hormone agonists (GnRHa) in order to see if a greater gain in height could be achieved by altering the tempo of pubertal maturation. Near-final height data were analysed in 39 adolescents (out of a total of 249) who had received GH + GnRHa therapy and were compared with similar data from 1,893 patients with IGHD treated with GH alone. The total change in height SDS in boys who received GH alone was +1.6, in contrast to +1.1 in GH + GnRHa-treated boys; the total change in height SDS in girls who received GH alone was +1.4 in contrast to +1.1 in girls treated with GH + GnRHa. The near final height SDS in girls treated with GH + GnRHa was 1.0 below the mid-parental target height (MPH), whereas there was only a -0.5 SDS difference in girls treated with GH. Approximation to the MPH did not differ in boys between the two treatment groups. These data suggest that the attainment of a substantial height SDS by manipulating the tempo of puberty is limited, but that optimizing growth during the pre-pubertal phase is a more important factor., (Copyright 2003 S. Karger AG, Basel)

Growth hormone (GH) has a positive impact on muscle mass, growth and bone formation. It is known to interact with the bone-forming unit, with well-documented increases in markers of bone formation and bone resorption within weeks of the start of GH therapy. These changes relate significantly to short-term growth rate, but it is not evident that they predict long-term response to GH therapy. The consequences of GH deficiency (GHD) and GH replacement therapy on bone mineral density (BMD) have been difficult to interpret in children because of the dependency of areal BMD on height and weight. Some studies have tried to overcome this problem by calculating volumetric BMD, but results are conflicting. The attainment of a normal peak bone mass in an individual is considered important for the future prevention of osteoporosis. From the limited data available, it appears difficult to normalize bone mass totally in GH-deficient individuals, despite GH treatment for long periods. Studies to date examining the interaction between GH and bone have included only small numbers of individuals, making it difficult to interpret the study findings. It is hoped that these issues can be clarified in future research by the direct measurement of bone density (using quantitative computer tomography). Mineralization is only one facet of bone strength, however; other important components (e.g. bone structure and geometry) should be addressed in future paediatric studies. Future studies could also address the importance of the degree of GHD in childhood; how GH dose and insulin-like growth factor-I levels achieved during therapy relate to the final outcome; whether or not the continuation of GH therapy after the attainment of final height may further enhance bone mass; whether the timing and dose of other treatments (e.g. sex hormone replacement therapy) are critical to the outcome; and whether GHD in childhood is associated with an increased risk of fracture., (Copyright 2000 S. Karger AG, Basel.)

We investigated the relationship between IGF-I, gender, height, weight, body composition and birth size in 260 healthy 7- and 8-year-old children (139 females). All children were born term at Nepean Hospital, Western Sydney. Body composition was measured using dual energy X-ray absorptiometry. IGF-I levels were determined by radioimmunoassay. Girls had higher IGF-I levels than boys (20.2 +/- 6.5 nmol/l compared to 15.9 +/- 6.1 nmol/l, p < 0.001) but there was no correlation between age and IGF-I. IGF-I was positively correlated with height SDS (R(2) = 0.12), weight SDS (R(2) = 0.19), BMI SDS (R(2) = 0.18), total body fat (%) (R(2) = 0.14), and fat-free tissue/cm (R(2) = 0.03). After adjusting for gender and current weight, IGF-I-levels were inversely related to birth size - children with the lowest birth size and heaviest current weight had the highest IGF-I levels. This correlation between birth weight and IGF-I supports the hypothesis that the IGF-I axis is altered in babies who are small for gestational age., (Copyright 2000 S. Karger AG, Basel)

A significant proportion of the morbidity related to obesity is now recognized to be related to the regional distribution of fat. The advent of dual energy X-ray absorptiometry has facilitated the assessment of body composition in a number of investigations on body fat. From current data, including the authors' own study of trunk and leg fat in 335 children and young adults, it is evident that gender differences for total body fat, percentage of body fat and distribution of fat occur after the pubertal years. Males develop a distribution of fat which favours central deposition of fat irrespective of their total body fat--a distribution that is, unfortunately, associated with a number of adverse implications on health. Furthermore, this tendency to increasing abdominal fat is independent of adipose tissue mass. Hormonal regulators of adipose tissue, including growth hormone which is already known to increase free fatty acids and decrease fat cell mass, need to be studied to account for these gender differences.