Ethinylestradiol and testosterone have divergent effects on circulating IGF system components in adolescents with constitutional tall stature.

OBJECTIVE: Pharmacological doses of estrogens or testosterone are used to limit the final height of girls or boys with constitutional tall stature but the mechanism behind this growth inhibition is still debated. We therefore studied the changes in the circulating components of the insulin-like growth factor (IGF) system during high dose sex steroid therapy. DESIGN AND METHODS: Twenty three girls and twenty boys with constitutional tall stature were treated with 100 microg ethinylestradiol per day or 250 mg testosterone ester every 14 days respectively. In 19 girls and 18 boys, the levels of IGF-I, free IGF-I, IGF-II, acid-labile subunit (ALS) and IGF binding proteins (IGFBP)-2 to -6 were measured before and 3-6 months after the start of therapy (group 1). In 18 girls and 11 boys, samples were collected at the end of therapy and 3 to 6 months afterwards (group 2). Fourteen girls and nine boys belonged to both groups. All parameters were measured by radioimmunoassay or ELISA. RESULTS: Levels of IGF-I were decreased significantly by estrogen treatment but remained unchanged during testosterone treatment. Free IGF-I decreased during estrogen treatment but increased during testosterone therapy. Estrogens increased IGF-II and testosterone reduced it. The important reduction of IGFBP-2 during estrogen therapy is not reproduced by androgen therapy, neither is the stimulation by estrogens of IGFBP-4. IGFBP-3 is not modulated by either sex steroid. We found that IGFBP-6 is up-regulated by testosterone but not by estrogens; the reverse is true for ALS, which increased during estrogen treatment but remained unchanged during testosterone treatment. CONCLUSIONS: Our findings demonstrate that androgens and estrogens exert differential effects on the circulating levels of several IGF components.

A nonmosaic 45,X karyotype in a mother with Turner's syndrome and in her daughter.

OBJECTIVE: To describe a woman with a nonmosaic (45,X) form of Turner's syndrome who gave birth to a girl with 45,X Turner syndrome. DESIGN: Patient report. SETTING: Outpatient clinic of a university hospital. PATIENT(S): A woman with typical phenotypic features of Turner syndrome and a 45,X karyotype and her daughter with the same karyotype. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Routine karyotype analysis on 200 white blood cells on two different occasions, on skin fibroblasts (1,000 mitoses) and on ovarian fibroblasts. Translocation of X-chromosome material was investigated by a complete X paint and fluorescent in situ hybridization analysis. RESULT(S): The patient had a spontaneous puberty and became pregnant on three occasions. Her first daughter has a normal karyotype, the second pregnancy ended in spontaneous abortion, and after the third pregnancy, a girl was born with a 45,X karyotype. Karyotype analysis of a large number of mitoses in three different cell types failed to demonstrate any mosaicism. Translocation of X-chromosome material was ruled out by fluorescent in situ hybridization analysis with an X paint. CONCLUSION(S): This is a rare case of pregnancy in a nonmosaic Turner syndrome patient and, to our knowledge, is the only one that resulted in a live-born baby with the same karyotype. Cryptic mosaicism could not be found despite thorough investigations. Some hypotheses are presented that may explain this unique event.

Growth and ovarian function in girls with 48,XXXX karyotype--patient report and review of the literature.

The loss of an X chromosome results in short stature and often in primary ovarian failure, but the effect of extra X chromosomes is less clear, especially in 48,XXXX women. We report a girl with a 48,XXXX karyotype with tall stature (181.8 cm), primary ovarian failure and low DHEAS levels. A review of the literature shows that, apart from an intellectual deficit, the phenotype is very heterogeneous. The few data that are available in the literature indicate that tall stature and primary ovarian failure are not essential characteristics of the 48,XXXX phenotype.

QTc interval prolongation and QTc dispersion in children and adolescents with type 1 diabetes.

OBJECTIVES: To evaluate whether QT interval, QT interval corrected for heart rate (QTc), and QTc dispersion changes are already present in children and adolescents with diabetes. STUDY DESIGN: QT interval, QTc, and QTc dispersion were measured on a 12-lead surface electrocardiogram in 60 children and adolescents with stable type 1 diabetes and in 63 sex- and age-matched control subjects. Differences were evaluated by using the Kolmogorov-Smirnov Z test. The number of patients with QTc > 440 ms was compared in the two groups. The possible influence of age, sex, diabetes duration, and glycosylated hemoglobin (HbA(1c)) was examined by using Spearman correlation analysis. RESULTS: Diabetic children had significantly longer QTc intervals and a significantly larger QTc dispersion. The number of individuals with a QTc >440 ms was significantly higher in the diabetic group (14/60) than in the control group (2/63). The effect of age on R-R interval and QTc dispersion in healthy children was less pronounced in children with diabetes. HbA(1C) values did not significantly correlate with any of the parameters. CONCLUSIONS: QTc prolongation and a larger QTc dispersion are already present in a significant proportion of children and adolescents with diabetes.

IGF-I, IGF-II, 'free' IGF-I and IGF-binding proteins-2 to -6 during high-dose oestrogen treatment in constitutionally tall girls.

OBJECTIVE: To investigate the effect of high-dose oestrogen treatment on IGF-I, IGF-II, free-dissociable IGF-I and the IGF-binding proteins (IGFBP)-2 to -6 in girls with constitutional tall stature. METHODS: In patient cohort 1, blood samples were drawn before and after 3 months of daily oral treatment with 0.1 mg ethinyloestradiol. In cohort 2, samples were collected at the end of the treatment period and 3 to 6 months afterwards. IGFs and IGFBPs were analysed by specific immunoassays and by Western ligand blot. RESULTS: Total IGF-I decreased significantly on oestrogen treatment and increased again after oestrogen withdrawal. Ligand blot analysis showed a clear reduction in a 34 kDa band, corresponding to IGFBP-2, and a strong induction of a 24 kDa band, corresponding to the non-glycosylated form of IGFBP-4. These changes were confirmed by specific immunological methods. The serum levels of IGFBP-3, IGFBP-5 and IGFBP-6 remained unchanged during the first 3 months of treatment. In cohort 2, IGFBP-3 and IGFBP-6 increased after oestrogen withdrawal. Free-dissociable IGF-I fell to 35+/-4% during oestrogen therapy and rose again when the treatment was stopped. CONCLUSIONS: Oestrogens modulate the serum concentrations of several components of the IGF system. The fall in total IGF-I is not explained by a decrease in IGFBPs but probably results from a decreased synthesis.

The incidence of type 1 diabetes in the age group 0-39 years has not increased in Antwerp (Belgium) between 1989 and 2000: evidence for earlier disease manifestation.

OBJECTIVE: A worldwide increase in the incidence of childhood type 1 diabetes has been observed. Because in various countries the majority of new type 1 diabetic patients are diagnosed in adulthood, we investigated whether the rising incidence of this disorder in children reflects a global increase in the incidence of diabetes or a shift toward earlier clinical presentation. RESEARCH DESIGN AND METHODS: The incidence of type 1 diabetes presenting before age 40 years was prospectively measured in the Antwerp district over a 12-year period (1989-2000). The completeness of ascertainment was evaluated by the capture-recapture method. Trends in incidence during the study period were analyzed by Poisson regression. RESULTS: The incidence of type 1 diabetes diagnosed before age 40 years remained constant over the 12-year period, averaging 9.9 cases per 100,000 individuals per year. The incidence was similar in both sexes under age 15 years, but a marked male excess was noted for adult-onset disease, in particular after age 20 years, resulting in a male-to-female ratio of 0.9 under age 15 years vs. 1.6 thereafter (P = 0.001). During the 12-year observation period, there was a significant tendency toward increasing incidence under age 15 years at the expense of a decreasing incidence between ages 15 and 40 years (P = 0.025). The annual increase in incidence averaged 1.8% under age 15 years and 5.0% under age 5 years (P = 0.06). CONCLUSIONS: Our results indicate that in Belgium, the increasing incidence of childhood type 1 diabetes-especially for children under age 5 years-is not attributable to a global increase in disease incidence, but rather to earlier clinical manifestation. The results suggest that an environmental factor may preferentially accelerate the subclinical disease process in young diabetes-prone subjects.