| 1. |
- Dahlgren, Jovanna, 1964, et al.
(author)
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Models predicting the growth response to growth hormone treatment in short children independent of GH status, birth size and gestational age
- 2007
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In: BMC Med Inform Decis Mak. - : Springer Science and Business Media LLC. - 1472-6947. ; 7
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Journal article (peer-reviewed)abstract
- BACKGROUND: Mathematical models can be used to predict individual growth responses to growth hormone (GH) therapy. The aim of this study was to construct and validate high-precision models to predict the growth response to GH treatment of short children, independent of their GH status, birth size and gestational age. As the GH doses are included, these models can be used to individualize treatment. METHODS: Growth data from 415 short prepubertal children were used to construct models for predicting the growth response during the first years of GH therapy. The performance of the models was validated with data from a separate cohort of 112 children using the same inclusion criteria. RESULTS: Using only auxological data, the model had a standard error of the residuals (SDres), of 0.23 SDS. The model was improved when endocrine data (GHmax profile, IGF-I and leptin) collected before starting GH treatment were included. Inclusion of these data resulted in a decrease of the SDres to 0.15 SDS (corresponding to 1.1 cm in a 3-year-old child and 1.6 cm in a 7-year old). Validation of these models with a separate cohort, showed similar SDres for both types of models. Preterm children were not included in the Model group, but predictions for this group were within the expected range. CONCLUSION: These prediction models can with high accuracy be used to identify short children who will benefit from GH treatment. They are clinically useful as they are constructed using data from short children with a broad range of GH secretory status, birth size and gestational age.
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| 2. |
- Nierop, Andreas FM, 1954, et al.
(author)
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Modelling individual longitudinal human growth from fetal to adult life - QEPS I
- 2016
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In: Journal of Theoretical Biology. - : Elsevier BV. - 0022-5193. ; 406, s. 143-165
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Journal article (peer-reviewed)abstract
- Background: Only one mathematical model to date describes human growth and its different phases from fetal life until adult height. Aim: To develop a model describing growth from fetal life to adult height taking maturation/biological tempo into consideration. Methods: Subjects: The model was developed based on longitudinal mean height values obtained from published growth references for a cohort of 3650 healthy Swedish children followed from birth circa 1974 until adult height combined with birth-length for circa 400 000 healthy infants born 1990-1995. Results: The QEPS-model for individual growth was constructed with a combination of four basic shape invariant growth functions: a quadratic Q-function and a negative exponential E-function, both started during fetal life, 8 months before birth; the E-function levelled off after birth, whereas the Q-function continued until end of growth. A specific nonlinear pubertal P-function started at onset of puberty, and a stop S-function ended growth according to both the Q-function continuing during puberty and the specific P-function. For each function, an individual height-scale parameter was defined, and for the E and P-functions, a time-scale parameter; giving six modifying parameters in total. In addition standardized proportional scores were used for biological interpretations. The QEPS-model was used to fit and generate mathematical functions suitable to describe the growth of the healthy population of Swedish children; thereafter, the model was modified using four height scale parameters to model individual height in cm, and two time-scale parameters to adjust for the individual tempo of growth. Individual confidence intervals were calculated for all parameters. Conclusions: A new shape-invariant growth model, QEPS, was developed, that requires only four basic growth functions to describe the total pattern of growth in height from fetal life to adult height, with addition of height- and time-scale parameters describing individual growth. The model can describe a wide variety of growth curves. Moreover, it is the first model to provide confidence intervals which enable us to describe the precision/quality of individual parameters.
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| 3. |
- Albertsson-Wikland, Kerstin, 1947, et al.
(author)
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Longitudinal follow-up of growth in children born small for gestational age.
- 1993
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In: Acta paediatrica (Oslo, Norway : 1992). - 0803-5253. ; 82:5, s. 438-43
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Journal article (peer-reviewed)abstract
- Postnatal growth was followed in a population-based group of 123 small-for-gestational-age (SGA, birth weight < -2 SD) children (66 boys and 57 girls) to four years of age in order to determine the incidence and time of catch-up growth. Gestational age was determined by ultrasound in gestational weeks 16-17 in all pregnancies, thus eliminating the problem of distinguishing between SGA and preterm infants. Infants with well-defined causes for slow growth rate, i.e. those infants with chromosomal disorders, severe malformations, intrauterine viral infections or cerebral palsy, were excluded. The boys showed an extremely fast weight catch-up, 85% of them reaching weights greater than -2 SD at the age of three months and remaining above this level to the end of the study period. Such a fast catch-up growth was observed in only two-thirds of the girls, but at four years of age 85% of the girls were also above -2 SD. Length catch-up was more gradual than weight catch-up. Of the boys, 54% had lengths below -2 SD at birth, 26% at 1 year of age, 22% at 2 years of age, 17% at 2.5 years of age and 11% (n = 8) at 4 years of age. Corresponding figures for girls were: 69% at birth, 28% at 1 year, 15% at 2 years, 12% at 2.5 years and 5% (n = 3) at 4 years. At 4 years of age, only six boys and three girls remained below -2 SD for both weight and height.(ABSTRACT TRUNCATED AT 250 WORDS)
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| 4. |
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| 5. |
- Ankarberg-Lindgren, Carina, 1963, et al.
(author)
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Leptin levels show diurnal variation throughout puberty in healthy children, and follow a gender-specific pattern
- 2001
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In: Eur J Endocrinol. ; 145:1, s. 43-51
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Journal article (peer-reviewed)abstract
- OBJECTIVE: To investigate the levels and diurnal rhythm of serum leptin in healthy children, and to investigate the association between leptin levels and sex steroids. METHODS: Four girls and four boys, all healthy volunteers, were followed longitudinally throughout puberty. Their chronological ages ranged from 8.7 to 19.5 years, and body composition, expressed as weight-for-height standard deviation scores (SDS), ranged between -1.7 and +2.4. Serum leptin, oestradiol and testosterone concentrations were measured by radioimmunoassay at 1000, 1400, 1800, 2200, 0200 and 0600 h. RESULTS: In all girls and boys, both prepubertally and during pubertal development, serum leptin levels increased during the night, with no difference in relative peak amplitude. In boys, the leptin concentrations increased until the initiation of puberty and then declined, whereas in girls, the concentrations increased throughout puberty. The inter-individual variation in mean leptin levels among girls decreased to 11% at the time of menarche. A positive correlation was found for both oestradiol and testosterone versus leptin in girls throughout puberty (r=0.64 and r=0.71 respectively, P<0.001). A negative correlation was found between leptin and testosterone in boys in mid- and late puberty (r=-0.66, P<0.01). No correlation was found between oestradiol and leptin in boys or between testosterone and leptin in pre- and early pubertal boys. CONCLUSION: Serum leptin concentrations show diurnal variation throughout pubertal development in both girls and boys. The changes in leptin levels during puberty follow a gender-specific pattern, probably due to an influence of sex steroids on leptin production.
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| 6. |
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| 7. |
- Blair, J. C., et al.
(author)
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Standard and low-dose IGF-I generation tests and spontaneous growth hormone secretion in children with idiopathic short stature
- 2004
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In: Clin Endocrinol (Oxf). ; 60:2, s. 163-8
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Journal article (peer-reviewed)abstract
- OBJECTIVE: Abnormalities in the GH-IGF-I axis, consistent with GH insensitivity (GHI), have been reported in some patients with idiopathic short stature (ISS). The standard IGF-I generation test (IGFGT) has not demonstrated mild GHI in subjects with ISS. The aim of this study was to investigate the GH-IGF-I axis in ISS by performing standard and novel low-dose IGFGTs together with determination of spontaneous GH secretion. PATIENTS AND METHODS: Twenty-one (17 male) prepubertal children with ISS, mean age 8.3 years (4.5-12.2), mean height -3.48 SD (-5.40 to -1.79), mean peak GH to provocation with glucagon/clonidine 32.3 mU/l (14.1-66.0) were studied. Serum IGF-I and IGFBP-3 levels were measured during standard (GH 0.033 mg/kg/day x 4) and low (GH 0.011 mg/kg/day x 4) dose IGFGTs at 0, 12, 36 and 84 h. The low-dose IGFGT was performed in seven naive GH-deficient patients (4 male), mean age 8.5 years (range 4.1-11.1). Determination of spontaneous 24-h GH secretion was performed in the 21 ISS patients. RESULTS: Basal IGF-I and IGFBP-3 standard deviation scores (SDS) in ISS patients were -1.39 (-2.4-1.16) and -0.45 (-1.13-0.38), respectively, IGF-I being lower than IGFBP-3 (P < 0.0001). IGF-I increased in the standard IGFGT at 12 h (P < 0.005), 36 h (P < 0.001) and 84 h (P < 0.001); maximal increment 1.54 (-0.32-3.48), and in the low-dose test at 12 h (P < 0.005), 36 h (P < 0.001) and 84 h (P < 0.005); maximal increment 0.53 (0.08 to -1.23). IGFBP-3 SDS increased in the standard IGFGT at 36 h (P < 0.01) and 84 h (P < 0.001); maximal increment 0.72 (-0.44-1.96), and in the low-dose test at 84 h (P < 0.005); maximal increment 0.33 (-0.08-0.87). Five/19 patients with an IGF-I response > 2 x coefficient of variation (CV) of assay in the standard test failed to respond in the low-dose test, suggestive of mild GHI. In GH-deficient patients, IGF-I increased at each time point (P < 0.05) and IGFBP-3 at 36 h (P < 0.05). Mean GH secretion, expressed in SDS, compared with 66 normal stature controls was: basal GH -0.48 (-0.84-0.93), height of GH peaks compared with zero -0.36 (-1.26-1.51) (both P < 0.05), total GH secretion -0.76 (-1.22-0.42), total GH secretion above baseline -0.67 (-1.21-0.94) (both P < 0.01). CONCLUSIONS: In children with ISS, basal IGF-I and IGFBP-3 SDS values were below the mean, IGF-I showing a greater response in both IGFGTs. In the standard IGFGT, the IGF-I increase at 36 h was equal to that at 84 h. The low-dose IGFGT, in combination with the standard test, may identify patients with mild GHI.
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| 8. |
- Boguszewski, M. C., et al.
(author)
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Insulin-like growth factor-1, leptin, body composition, and clinical status interactions in children with cystic fibrosis
- 2007
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In: Horm Res. - : S. Karger AG. - 0301-0163. ; 67:5, s. 250-6
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Journal article (peer-reviewed)abstract
- BACKGROUND/AIMS: Children with cystic fibrosis (CF) are of increased risk of reduced fat body mass (FBM) and lean body mass (LBM). Serum concentrations of insulin-like growth factor-1 (IGF-1)and leptin could be markers of LBM and/or FBM depletion. To evaluate the relationships between disease activity, body composition, IGF-1 and leptin concentrations in CF children. METHODS: A cross-sectional study with 26 CF children aged 5.0-15.5 years and 33 healthy controls, mean age 9.4 years. Body composition was evaluated by dual-energy X-ray absorptiometry. Fasting blood samples were analyzed for leptin, IGF-1 and IGFBP-3. RESULTS: FBM standard deviation score (SDS; CF boys -0.02 +/- 0.88 vs. 0.78 +/- 0.65, p < 0.01; CF girls -0.37 +/- 1.15 vs. 0.70 +/- 0.97, p < 0.05), leptin concentration (CF boys 2.07 +/- 0.79 vs. 3.07 +/- 1.28 ng/ml, p < 0.05; CF girls 2.71 +/- 0.86 vs. 5.00 +/- 2.95 ng/ml, p < 0.05) and IGF-1SDS (CF boys -1.43 +/- 1.50 vs. -0.32 +/- 0.88, p < 0.05; CF girls -0.66 +/- 1.66 vs. 0.64 +/- 0.57, p < 0.01) were lower in CF children compared to controls. Shwachman score was the strongest predictor of lean body mass (R = 0.63). Leptin levels explain 60% of the variability in FBM. CONCLUSION: Serum concentrations of IGF-1 and leptin are decreased in children with CF and are associated with clinical conditions and body composition.
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| 9. |
- Carlsson, Björn, 1958, et al.
(author)
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Serum leptin concentrations in relation to pubertal development.
- 1997
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In: Archives of disease in childhood. - 1468-2044. ; 77:5, s. 396-400
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Journal article (peer-reviewed)abstract
- The amount of adipose tissue influences pubertal development and fertility in girls. A candidate for mediating this is the hormone leptin, derived from adipocytes. This work was carried out to determine whether the leptin concentration in serum is regulated during pubertal development.
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| 10. |
- Lundberg, Elena, et al.
(author)
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Broad variability in pharmacokinetics of GH following rhGH injections in children
- 2018
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In: Growth Hormone & Igf Research. - : Elsevier BV. - 1096-6374 .- 1532-2238. ; 40, s. 61-68
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Journal article (peer-reviewed)abstract
- Objective: Daily subcutaneous self-injection of GH is used worldwide to treat short stature in childhood; longitudinal data on the impact of this regimen on GH-uptake are lacking. Design: Children with/without GH-deficiency participating in clinical trials were followed prospectively ( s 8 times). Blood was sampled pre-GH-injection (dose GH(33)/GH(67) mu g/kg) and either every 30 min thereafter for 24 h (Experimental-setting; 59 GH-curves/15 children); or every 2 h thereafter for 16 h (Clinical-setting; 429 GHcurves/117 children). Pharmacokinetics were estimated by time T-max (h) of maximal GH-concentration (C-max , mU/L) and area under the curve for 16 h (AUC, mU/L * h). Results: In the Clinical-setting, median C-max was 71 mU/L and AUC was 534 mU/L * h, with coefficients of variation for intra-individual variation of 39% and 36%, respectively, and inter-individual variation of 44% and 42%, respectively. 43% of C-max and AUC variability was explained by GH-dose and proxies for injection depth (baseline GH-level, GH(peak) width, BMISDS). In the Experimental- versus Clinical-setting, 85% and 40% of GH-curves, respectively, reached zero-levels within 24 h. A longer duration was found following a more superficial GH-injection. Spontaneous GH-peaks were identified already 6 h after the GH-injection in about half of the curves of both GHD and non-GHD patients. Conclusion: Very broad intra-individual and inter-individual variability was found. A high GH-peak will optimize growth effects; the highest C-max was found after a deep injection of GH at the higher dose and concentration. In as many as 60% of the children, GH remained detectable in serum after 24 h; a constant GH-level will promote IGF-I and metabolic effects.
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