Role of Wnt-signaling inhibitors DKK-1 and sclerostin in bone fragility associated with Turner syndrome

PURPOSE

Girls affected with Turner syndrome (TS) present with low bone mineral density (BMD) and osteopenia/osteoporosis. Thus, they have an increased risk to develop fractures compared to normal population. The aim of this study was to deepen the pathophysiology of skeletal fragility in TS subjects by evaluating the serum levels of Dickkopf-1 (DKK-1) and sclerostin, main regulators of bone mass, as well as the percentage of circulating osteoblast precursors (OCPs).

METHODS

Thirty-four TS girls and 24 controls were recruited. All subjects underwent anthropometric measures (height, weight, body mass index-BMI). A peripheral venous blood sample was collected to determine serum levels of active intact parathyroid hormone (PTH), 25-OH vitamin D, calcium, phosphorus, bone alkaline phosphatase (bALP), osteocalcin, sclerostin, DKK-1, RANKL and OPG. OCPs were detected by flow cytometry. In TS subjects bone mineralization was measured at lumbar spine by dual energy X-ray absorptiometry (DXA).

RESULTS

bALP, 25-OH Vitamin D, and osteocalcin levels were significant lower in TS subjects than in the controls. Statistically significant higher levels of sclerostin, DKK-1 and RANKL were measured in patients compared with the controls. The percentage of OCPs did not show significant differences between patients and controls. Sclerostin and DKK-1 levels were related with anthropometric parameters, bone metabolism markers, HRT, rhGH therapy, RANKL and lumbar BMAD-Z-score.

CONCLUSION

TS patients showed higher levels of sclerostin and DKK-1 than controls which can be related to HRT, and to reduced bone formation markers as well as the increased bone resorption activity.

GH Responsiveness Is not Correlated to IGF1 P2 Promoter Methylation in Children With Turner Syndrome, GHD and SGA Short Stature

BACKGROUND

The methylation of IGF1 promoter P2 was reported to negatively correlate with serum IGF-1 concentration and rhGH treatment response in children with idiopathic short stature. These findings have not yet been confirmed.

OBJECTIVE

This study aimed to determine IGF1 promoter P2 methylation in short children treated with rhGH and correlate clinical parameters with the methylation status. In addition, long-term stability of methylation during rhGH treatment was studied.

DESIGN

This was a single tertiary center study analyzing clinical GH response and IGF-1 serum concentration changes in patients with GHD (n=40), SGA short stature (n=36), and Turner syndrome (n=16) treated with rhGH. Data were correlated to the methylation of two cytosine residues (-137, +97) of the P2 promoter of IGF1 in blood cells measured by pyrosequencing in 443 patient samples.

RESULTS

Basal and stimulated IGF-1 concentrations, first year increment in height velocity and studentized residuals of a prediction model did not correlate to the methylation of -137 und +97 in IGF1 P2 promoter. The methylation of these two sites was relatively stable during treatment.

CONCLUSIONS

This study did not confirm IGF1 P2 promotor being a major epigenetic locus for GH responsiveness in patients treated with a normal dose of rhGH. Additional studies are warranted.

Brain-Derived Neurotropic Factor, Vascular Endothelial Growth Factor and Matrix Metalloproteinases as Markers of Metabolic Status in Non-Growth Hormone-Treated Girls With Turner Syndrome

BACKGROUND

Turner syndrome (TS) presents a high risk of congenital heart defects and may predispose to both obesity and related metabolic complications. Hence the search for new markers as potential early predictors of the metabolic syndrome (MetS) and cardiovascular diseases appears warranted.

OBJECTIVE

To assess MMP-1 (matrix metalloproteinase-1), MMP-2 (matrix metalloproteinase-2), MMP-9 (matrix metallopeptidase-9), BDNF (brain-derived neurotrophic factor), GDNF (glial cell line-derived neurotrophic factor), and VEGF (vascular endothelial growth factor) in non-MetS TS girls not treated with growth hormone (GH) vs. healthy short stature girls, and to assess the connection with basic metabolic parameters.

METHOD

The concentrations of circulating MMP-1, MMP-2, MMP-9, BDNF, GDNF and VEGF were measured in 12 patients with TS not treated with growth hormone. The control group was composed of 17 girls with non-pathologic short stature. The patients' clinical and biochemical phenotypes were determined by weight, height, total cholesterol, HDL cholesterol, triglycerides, glucose, aminotransferases, IGF1, TSH and fT4.

RESULTS

There were no differences in mean age, weight, BMI Z-Score, or hSDS between the studied group and the controls; however, they differed in baseline values of ALT (18.2 ± 4.2 vs. 14.2 ± 4.1, p= 0.02), BDNF [29951.5 (26176.9 - 41271.9) vs. 23131.7 (18392.4 - 28313.3), p=0.01] and MMP-2 [91.8 (71.7 - 111.0) vs. 143.6 (123.7 - 244.5), p< 0.001]. BDNF correlated with ALT activity (r = 0.56 p = 0.002) and BMI Z-score (r = 0.38 p = 0.042), while MMP-2 correlated with HDL concentration (r = 0.48 p = 0.029) in all the patients. The analysis of the study group alone revealed significant positive correlations between MMP-9 and TSH (r = 0.74 p = 0.036), BDNF and both ALT (r = 0.73 p = 0.038) and TSH (r = 0.85 p = 0.008), and a negative correlation between MMP-1 and fT4 (r = -0.75 p = 0.032). The control group did not present any significant correlations.

CONCLUSION

The higher concentrations of BDNF and lower of MMP-2 found in girls with TS without MetS compared to healthy girls with short stature, could have a major impact on the future "natural" development of the metabolic status. Our findings need further studies.

Blood pressure, sympathovagal tone, exercise capacity and metabolic status are linked in Turner syndrome

OBJECTIVES

We studied cardiac autonomic changes in relation to metabolic factors, body composition and 24-hour ambulatory blood pressure measurements in Turner syndrome patients without known hypertension.

DESIGN

Cross sectional.

PATIENTS

Participants were 48 TS women and 24 healthy female controls aged over 18 years.

METHODS

Short-term power spectral analysis was obtained in supine-standing-supine position. Bedside tests included three conventional cardiovascular reflex tests of heart rate response to standing up, heart rate response to deep breathing and blood pressure response to standing up. Mean heart rate during the last 2 minutes of work was used to calculate the maximal aerobic power (VO_2max ).

RESULTS

We found a significantly higher mean reciprocal of the heart rate per second (RR) in TS. Testing for interaction between position and status (TS or control), there were highly significant differences between TS and controls in high-frequency (HF) power, the coefficient of component variation (square root of HF power/mean RR) and low-frequency (LF): HF ratio, with a dampened decline in vagal activity among TS during standing. Bedside test showed TS had a significantly higher diastolic BP in the supine position compared to controls, and the adaptive rise in BP, when changing to upright position was reduced. VO_2max and self-reported level of physical activity were significantly correlated to systolic ambulatory blood pressure both 24-hour and night diastolic ambulatory blood pressure.

CONCLUSION

Vagal tone and modulation of the sympathovagal balance during alteration in body position are impaired in TS. These changes can be risk factors for cardiovascular disease.

Adrenarche and pubarche in girls with turner syndrome during growth-promoting therapy with human growth hormone

BACKGROUND

Data on adrenarche and pubarche in girls with Turner syndrome (TS) are inconsistent in the literature.

METHODS

The cohort consisted of 94 girls and young women with TS born between 1971 and 2001 (age range: 3.1-23.2 yrs.), who were treated with human growth hormone and regularly presented at our outpatient clinic every 4 to 6 months.The longitudinal data of all patients were ascertained retrospectively from patient charts. The data collection ended in January 2016. Adrenarche was assessed by serum DHEAS levels and pubertal status by Tanner stages. Pubarche was defined as the appearance of pubic hair (PH2), whereas spontaneous puberty was defined as Tanner stage B2. The patients were retrospectively subdivided in two groups with regard to pubertal development: group 1 (n = 21) with spontaneous puberty and group 2 (n = 70) with induced puberty. Since blood samples were not taken at every visit, we generated seven groups according to the age of the children at which the blood samples were taken: 3-5, 5-7, 7-9, 9-11, 11-13, 13-15, and 15-17 yrs. Serum DHEAS and follicle-stimulating hormone (FSH) levels were measured by chemiluminescence immunoassay and compared with those of a control group of healthy girls.

RESULTS

Adrenarche started in TS girls between 5 and 7 years. TS girls had higher DHEAS levels than the control group, with statistically significant differences in the age groups 7 to 17 years. No differences were determined between the TS girls with spontaneous puberty and those with POI. TS girls in group 2 reached the Tanner stages PH2 (p < 0.04), PH3 (p < 0.01), PH4 and PH5 (p < 0.001) markedly later than TS girls in group 1.

CONCLUSIONS

The onset of adrenarche in girls with TS undergoing GH therapy does not differ from that in healthy girls. However, adrenarche is more pronounced in girls with TS. There is no difference in DHEAS levels between the TS girls with spontaneous puberty and the TS girls with primary ovarian insufficiency (POI), while the tempo of pubarche is markedly slower in the girls with POI.

Liver biochemical abnormalities in Turner syndrome: A comprehensive characterization of an adult population

OBJECTIVE

Abnormal liver function tests (LFTs) are frequent in Turner syndrome (TS). The causes and clinical significance are unclear.

AIMS

To investigate the prevalence of elevated LFTs in adult TS; secondly, to analyse the associations between elevated LFTs, TS-karyotypes and TS-related conditions; and thirdly, to evaluate liver stiffness and histological assessment.

METHODS

A total of 125 TS women were retrospectively studied. Karyotypes, clinical and biochemical details and aortic measurements were recorded. Fibroscan and liver biopsy results were noted.

RESULTS

Elevated LFTs were found in 49.6%: gamma-glutamyltransferase (GGT) in 88.7%, ALK in 45.2%, ALT in 40.3% and AST in 29%. A FIB-4 index >1.3 was found in 11.8%. Women with isochromosome of the X long arm, iso[X](q), had a higher prevalence of elevated LFTs. A lower prevalence of abnormal GGT was found in patients with 45,X/46,XX, 45,X/47,XXX or 45,X/46,XX/47,XXX. Subjects with raised GGT were older, shorter and more likely to have higher triglyceride levels. There was no association with HRT duration after adjusting for age. Among patients with elevated aminotransferases, no differences were noted, except for higher HDL-cholesterol levels. The sinuses and ascending aorta diameter were greater in the elevated LFTs group. Fibroscan was suggestive of significant liver fibrosis in 38.1%. Among 11 biopsies, liver architectural changes were reported in 45.4%, including two with cirrhosis.

CONCLUSIONS

Elevated LFTs in TS are common and important to detect given the possible progression towards severe liver disease. An association between raised LFTs and karyotype iso[X]q was demonstrated. We have also shown a new association between abnormal LFTs and aortic dilatation.

Generation of an induced pluripotent stem cell line from an adult male with 45,X/46,XY mosaicism

Turner syndrome (TS) with 45,X/46,XY mosaic karyotype is a rare sex chromosome disorder with an occurrence of 0.15‰ at birth. We report the generation of an induced pluripotent stem cell (iPSC) line from peripheral blood mononuclear cells of a Chinese adult male with 45,X/46,XY mosaicism. The iPSC line retains the original 45,X/46,XY mosaic karyotype, expresses pluripotency markers and undergoes trilineage differentiation. Therefore, it offers an unprecedented cellular model to investigate the profound symptoms like infertility of TS in the male, and serve as a useful tool to develop therapies for the disease.

Clinical practice guidelines for the care of girls and women with Turner syndrome: proceedings from the 2016 Cincinnati International Turner Syndrome Meeting

Turner syndrome affects 25-50 per 100,000 females and can involve multiple organs through all stages of life, necessitating multidisciplinary approach to care. Previous guidelines have highlighted this, but numerous important advances have been noted recently. These advances cover all specialty fields involved in the care of girls and women with TS. This paper is based on an international effort that started with exploratory meetings in 2014 in both Europe and the USA, and culminated with a Consensus Meeting held in Cincinnati, Ohio, USA in July 2016. Prior to this meeting, five groups each addressed important areas in TS care: 1) diagnostic and genetic issues, 2) growth and development during childhood and adolescence, 3) congenital and acquired cardiovascular disease, 4) transition and adult care, and 5) other comorbidities and neurocognitive issues. These groups produced proposals for the present guidelines. Additionally, four pertinent questions were submitted for formal GRADE (Grading of Recommendations, Assessment, Development and Evaluation) evaluation with a separate systematic review of the literature. These four questions related to the efficacy and most optimal treatment of short stature, infertility, hypertension, and hormonal replacement therapy. The guidelines project was initiated by the European Society for Endocrinology and the Pediatric Endocrine Society, in collaboration with The European Society for Pediatric Endocrinology, The Endocrine Society, European Society of Human Reproduction and Embryology, The American Heart Association, The Society for Endocrinology, and the European Society of Cardiology. The guideline has been formally endorsed by the European Society for Endocrinology, the Pediatric Endocrine Society, the European Society for Pediatric Endocrinology, the European Society of Human Reproduction and Embryology and the Endocrine Society. Advocacy groups appointed representatives who participated in pre-meeting discussions and in the consensus meeting.

Prevalence and Physical Distribution of SRY in the Gonads of a Woman with Turner Syndrome: Phenotypic Presentation, Tubal Formation, and Malignancy Risk

Although monosomy X is the most common karyotype in patients with Turner syndrome, the presence of Y chromosome material has been observed in about 10% of patients. Y chromosome material in patients with Turner syndrome poses an increased risk of gonadoblastoma and malignant transformation. We report a woman with a diagnosis of Turner syndrome at 12 years of age, without signs of virilization, and karyotype reported as 46,X,del(X)(q13). At 26 years, cytogenetic studies indicated the patient to be mosaic for monosomy X and a cell line that contained a du-plicated Yq chromosome. Bilateral gonadectomy was performed and revealed streak gonads, without evidence of gonadoblastoma. Histological analysis showed ovarian stromal cells with few primordial tubal structures. FISH performed on streak gonadal tissue showed a heterogeneous distribution of SRY, with exclusive localization to the primordial tubal structures. DNA extraction from the gonadal tissue showed a 6.5% prevalence of SRY by microarray analysis, contrasting the 86% prevalence in the peripheral blood sample. This indicates that the overall gonadal sex appears to be determined by the majority gonosome complement in gonadal tissue in cases of sex chromosome mosaicism. This case also raises questions regarding malignancy risk associated with Y prevalence and tubal structures in gonadal tissue.

The Influence of GH Treatment on Glucose Homeostasis in Girls With Turner Syndrome: A 7-Year Study

CONTEXT

Growth hormone (GH) influences glucose homeostasis mainly by negatively affecting insulin sensitivity.

OBJECTIVE

To longitudinally study insulin sensitivity [via homeostasis model assessment of insulin sensitivity (HOMA-S)], insulin secretion [insulinogenic index (IGI)], and capacity of β cells to adapt to changes in insulin sensitivity [oral disposition index (ODI)] in girls with Turner syndrome (TS) undergoing GH treatment.

DESIGN AND SETTING

Longitudinal, retrospective, 7-year study conducted in a tertiary pediatric endocrine unit and university pediatric clinic.

PATIENTS AND METHODS

We studied 104 patients with TS (mean age ± standard deviation, 9.1 ± 3.4 years) for a median of 7.2 years.

INTERVENTION

Every year, the children underwent an oral glucose tolerance test, which was used to calculate HOMA-S, IGI, and ODI.

RESULTS

HOMA-S, IGI, and ODI did not significantly change.

CONCLUSION

The results are reassuring, showing no negative influence of GH treatment on insulin sensitivity and on β-cell secretory capacity in girls with TS.

Body composition and bone mineral status in patients with Turner syndrome

Turner syndrome (TS) is associated with decreased bone mineral density and increased fracture rate. However, the developmental trajectory of bone density or body composition in patients with TS is still unclear. The present study tested the hypothesis that different karyotypes and/or age contributes to abnormal body composition and decreased bone mineral status parameters in patients with TS. This study included 24 girls with TS, in which 13 girls exhibited X0 karyotype and 11 had mosaicism. Quantitative ultrasound (QUS) assessed the bone mineral status of the calcaneus, including bone mineral density (BMD), amplitude-dependent speed of sound (AD-SOS), broadband ultrasound attenuation (BUA) and InBody 770 assessed body composition. Pearson's test was performed to correlate measured parameters with patient age. The body composition and bone mineral status parameters were not significantly influenced by patient karyotype. There was a correlation between patient age and AD-SOS (r = -0.61, P = 0.002) and BUA (r = 0.50, P = 0.013) but not BMD (r = -0.19, P = 0.379). In conclusion, there was no effect of karyotype on body composition or body mineral status. Bone mineral status, as evidenced by changes in AD-SOS and BUA, alters with age regardless of karyotype. The developmental trajectory demonstrated in the current study warrants further validation in a longitudinal study.

Turner syndrome patients with bicuspid aortic valves and renal malformations exhibit abnormal expression of X-linked inhibitor of apoptosis protein (XIAP)

OBJECTIVE

We analyzed mRNA expression of X-linked inhibitor of apoptosis protein (XIAP) in patients with Turner syndrome (TS) and examined its association with phenotypic features.

SUBJECTS AND METHODS

XIAP mRNA expression levels were investigated in 98 patients with TS in total RNA extracted from blood leucocytes by real time quantitative polymerase chain reaction.

RESULTS

Levels of XIAP mRNA were significantly lower in patients with bicuspid aortic valves (BAV; n=13) than those without (log XIAP -1.17±0.3 vs. -0.94±0.2, p=0.002). Significantly higher expression of XIAP mRNA was seen in patients with a mosaic karyotype and renal malformations (log XIAP -0.79±0.3 vs. -1.0±0.3, p=0.03). No correlations were seen between XIAP and other manifestations.

CONCLUSION

Abnormal expression of XIAP may be an important underlying mechanism in the development of BAV and renal malformations in TS. However, abnormal XIAP mRNA expression, as determined from peripheral mononuclear cells, does not appear to explain all the somatic and visceral stigmata of TS.

Is there a role for estrogen activity assays? Recombinant cell bioassay for estrogen: Development and applications

There are many questions which cannot be answered without a very sensitive estradiol assay. A recombinant cell bioassay (RCBA) for estradiol was developed in 1994. The sensitivity of the bioassay is 0.02-0.2 pg/ml (0.07-0.7 pmol/L), more than 20 times more sensitive than commercial RIAs and 10 times more sensitive than newer mass spectrometry assays. The RCBA for estradiol opened the door to study low levels of estradiol equivalents (EE) across the physiological spectrum of life from prepubertal children through menopause and across the spectrum from normal physiology, in boys as well as girls, to pathology, including: premature thelarche; estradiol suppression in children treated with GnRH analogues for precocious puberty; aromatase inhibition in boys with growth hormone deficiency; the differences between oral and transdermal routes of estrogen administration in girls with Turner's syndrome; women with breast cancer treated with aromatase inhibitors; and women with urogenital atrophy treated with low dose vaginal estrogen. A bioassay also allows study of endocrine disruptors, like phytoestrogens and other environmental compounds, which are relevant to public health and alternative medicine options. This paper reviews the assay and the last 20 years of applications. A bioassay for estrogen has a role because measuring biological effect is theoretically useful, increasing the understanding of physiology in addition to biochemical levels, giving different information than other assays, and opening the door to measure very low levels of estrogen activity in both humans and the environment.

Low myocardial glucose uptake in Turner syndrome is unaffected by growth hormone: a randomized, placebo-controlled FDG-PET study

BACKGROUND

An unfavourable cardiovascular and metabolic phenotype causes threefold excess mortality in Turner syndrome (TS), and perturbed cardiac substrate metabolism is increasingly recognized as a common component of cardiovascular and metabolic diseases. We therefore hypothesized that myocardial glucose uptake (MGU) is reduced in TS and that growth hormone (GH) treatment improves MGU. To this end, this controlled trial elucidates MGU in TS and the impact of 6 months of growth hormone treatment on MGU.

METHODS AND RESULTS

Women with TS (n = 9) were examined at baseline, sequentially treated with either Norditropin(®) SimpleXx or placebo and re-examined after 6 months. MGU and myocardial blood flow (MBF) were measured using 2-deoxy-2-[18F]fluoro-D-glucose positron emission tomography (FDG-PET) during a hyperinsulinaemic euglycaemic clamp (at baseline and 6 months). Blood pressure measurement, blood sampling, echocardiography and dual energy X-ray absorptiometry scan were also performed. Age-matched female controls (n = 9) were examined once. Baseline MGU was reduced in TS (0.24 ± 0.08 vs. 0.36 ± 0.13 μmol/g/min in controls; P = 0.036) despite similar insulin sensitivity (whole body glucose uptake (M-value): 9.69 ± 1.86 vs. 9.86 ± 2.58 mg/(min*kg) in controls; P = 0.9). Six months of GH carried no impact on MGU (0.25 ± 0.08 vs. 0.26 ± 0.12 μmol/g/min in the placebo group; P = 0.8). Plasma glucose, low-density cholesterol and triglycerides increased, while M-value and exercise capacity decreased during 6 months of GH treatment.

CONCLUSION

MGU is reduced in TS despite normal insulin sensitivity. GH treatment does not alter MGU despite decreased whole body insulin sensitivity. A perturbed cardiac glucose uptake appears to be a feature of TS.

The Turner syndrome in patient with 45X/47XXX mosaic karyotype--case report

BACKGROUND

Turner syndrome (TS) is a gonadal dysgenesis related to partial or total lack of one of the X chromosomes. It this report we describe a young patient presenting some somatic features of TS, who underwent spontaneous puberty and was eumenoorheic up to the age of 23.

METHODS

Using fluorescent in situ hybridization (FISH) mosaic karyotype (45X[131]/47XXX[9]) of TS and triple X syndrome was found.

RESULTS

She presented uncommon for TS somatic hemihypotrophy and underwent growth hormone and surgical therapy. The patient was diagnosed with premature ovarian failure when she was 23, with absent follicular reserve. Clinical features of this case and a few published cases will be reviewed briefly.

Insulin resistance in adolescents with Turner syndrome is comparable to obese peers, but the overall metabolic risk is lower due to unknown mechanism

PURPOSE

An increased risk of insulin resistance, hypertension and liver dysfunction is related to obesity (Ob), but may be also present in normal-weight Turner syndrome (TS) patients. The aim of the study was to compare metabolic risk in adolescents with TS and Ob.

METHODS

The study included 21 non-obese with TS (all receiving human recombinant growth hormone, 17/21 estrogen/estrogen-progesterone), and 21 age-matched Ob girls (mean age 13.9 years). Glucose and serum insulin levels were assessed fasting and in 120' of standard oral glucose tolerance test. Levels of triglycerides (TG), total cholesterol (TC), low-density lipoprotein (LDL) and high-density lipoprotein (HDL) cholesterol, alanine aminotransferase (ALT), FGF19, FGF21 and FGF23 levels were measured fasting.

RESULTS

Mean BMI SDS was significantly lower in TS patients (0.1 vs 4.8 SD, p < 0.001). The mean systolic and diastolic blood pressure was significantly lower in TS patients (102.6 vs 124.2 mmHg, p < 0.001 and 67.1 vs 76.5 mmHg, p = 0.02). There were no differences concerning mean fasting, and post-load glucose (4.5 vs 4.3, 5.1 vs 5.8 mmol/L), and insulin (14.97 vs 17.19 and 69.3 vs 98.78 μIU/mL) levels, HOMA-IR (3.02 vs 3.4), TC (4.05 vs 4.4 mmol/L), TG (1.25 vs 1.37 mmol/L), ALT (26.9 vs 28.3 IU/L), FGF19 (232.8 vs 182.7 pg/mL), and FGF23 (12.3 vs 17.5 pg/mL) levels. Mean LDL (2.05 vs 2.7 mmol/L, p = 0.003) and FGF21 (293.9 vs 514.7 pg/mL, p = 0.007) levels were significantly lower, and HDL (1.7 vs 1.2 mmol/L, p < 0.001) level higher in TS group.

CONCLUSIONS

Insulin resistance in adolescents with TS on growth hormone treatment is comparable to Ob patients, but overall metabolic risk factors seem to be lower.

Management and interpretation of heterogeneous observational data: using insulin-like growth factor-I data from the NordiNet® International Outcome Study

OBJECTIVE

The NordiNet® International Outcome Study (IOS), a large-scale, non-interventional, multi-centre, real-world study of Norditropin® treatment, registers insulin-like growth factor-I (IGF-I) values, as measured by different assays. This paper considers the potential biases introduced by using a single IGF-I reference data set in analysing NordiNet® IOS data.

DESIGN

To evaluate possible biases from different IGF-I assays used across NordiNet® IOS, a mixed-effect linear model was fitted to IGF-I data (analyses on log-transformed data). Pre-growth hormone treatment (pre-GHT) IGF-I values were assumed to depend on diagnosis, sex and age. During GHT, a treatment-effect dependent on these factors was added. Differences between assays were assumed multiplicative on the original scale. Individual measurements were scaled to a common level (Nichols Advantage) giving adjusted IGF-I standard deviation score (SDS) values.

RESULTS

In total, 49 495 IGF-I measurements were available from 9481 paediatric patients. Mixed-effect linear modelling showed a systematic difference between IGF-I levels measured by different assays. Differences were minimised when assessing change in IGF-I SDS from the start of GHT to 1-year follow-up. This applied to values adjusted for actual-assay used and for unadjusted delta IGF-I SDS values. Largest differences between unadjusted change in IGF-I SDS values were: for growth hormone deficiency 0.1 (girls) and 0.3 (boys); for small-for-gestational age 0.1; and for Turner syndrome 0.2. Similar magnitude differences were seen for data with unknown assay.

CONCLUSIONS

Analysis and modelling suggest the current approach to IGF-I data collection and analyses in the NordiNet® IOS is sound: in a large cohort without assay-used information, potential bias is minimised by analysing changes in IGF-I SDS.

[TREATMENT OF SHORT STATURE PATIENTS WITH NOPMAL GROWTH HORMONE SECRETION OF HYPOPHIS]

The article presents the treatment outcome in 86 children with short stature associated with different endocrine pathology and saved growth hormone secretion (congenital adrenal hyperplasia chondrodystrophy, Turner syndrome, idiopathic short stature, syndrome biologically inactive growth hormone and other genetically determined pathology). This study extends prior knowledge about the outcomes of the treatment with recombinant growth hormone and luteinizing hormone--releasing hormone analogue (alone or in combination) in short patients with poor prognosis of final height.

A pharmacogenomic approach to the treatment of children with GH deficiency or Turner syndrome

OBJECTIVE

Individual sensitivity to recombinant human GH (r-hGH) is variable. Identification of genetic factors contributing to this variability has potential use for individualization of treatment. The objective of this study was to identify genetic markers and gene expression profiles associated with growth response on r-hGH therapy in treatment-naïve, prepubertal children with GH deficiency (GHD) or Turner syndrome (TS).

DESIGN

A prospective, multicenter, international, open-label pharmacogenomic study.

METHODS

The associations of genotypes in 103 growth- and metabolism-related genes and baseline gene expression profiles with growth response to r-hGH (cm/year) over the first year were evaluated. Genotype associations were assessed with growth response as a continuous variable and as a categorical variable divided into quartiles.

RESULTS

Eleven genes in GHD and ten in TS, with two overlapping between conditions, were significantly associated with growth response either as a continuous variable (seven in GHD, two in TS) or as a categorical variable (four more in GHD, eight more in TS). For example, in GHD, GRB10 was associated with high response (≥ Q3; P=0.0012), while SOS2 was associated with low response (≤ Q1; P=0.006), while in TS, LHX4 was associated with high response (P=0.0003) and PTPN1 with low response (P=0.0037). Differences in expression were identified for one of the growth response-associated genes in GHD (AKT1) and for two in TS (KRAS and MYOD1).

CONCLUSIONS

Carriage of specific growth-related genetic markers is associated with growth response in GHD and TS. These findings indicate that pharmacogenomics could have a role in individualized management of childhood growth disorders.

Prepubertal girls with Turner syndrome and children with isolated SHOX deficiency have similar bone geometry at the radius

CONTEXT

The low bone mineral density (BMD) and alterations in bone geometry observed in patients with Turner syndrome (TS) are likely caused by hypergonadotropic hypogonadism and/or by haploinsufficiency of the SHOX gene.

OBJECTIVE

Our objective was to compare BMD, bone geometry, and strength at the radius between prepubertal girls with TS and children with isolated SHOX deficiency (SHOX-D) to test the hypothesis that the TS radial bone phenotype may be caused by SHOX-D.

DESIGN AND SETTING

This comparative cross-sectional study was performed between March 2008 and May 2011 in 5 large centers for pediatric endocrinology.

PATIENTS

Twenty-two girls with TS (mean age 10.3 years) and 10 children with SHOX-D (mean age 10.3 years) were assessed using peripheral quantitative computed tomography of the forearm.

MAIN OUTCOMES

BMD, bone geometry, and strength at 4% and 65% sites of the radius were evaluated.

RESULTS

Trabecular BMD was normal in TS (mean Z-score = -0.2 ± 1.1, P = .5) as well as SHOX-D patients (mean Z-score = 0.5 ± 1.5, P = .3). At the proximal radius, we observed increased total bone area (Z-scores = 0.9 ± 1.5, P = .013, and 1.5 ± 1.4, P = .001, for TS and SHOX-D patients, respectively) and thin cortex (Z-scores = -0.7 ± 1.2, P = 0.013, and -2.0 ± 1.2, P < .001, respectively) in both groups. Bone strength index was normal in TS as well as SHOX-D patients (Z-scores = 0.3 ± 1.0, P = .2, and 0.1 ± 1.3, P = .8, respectively).

CONCLUSIONS

The similar bone geometry changes of the radius in TS and SHOX-D patients support the hypothesis that loss of 1 copy of SHOX is responsible for the radial bone phenotype associated with TS.

Metabolic effects of oral versus transdermal 17β-estradiol (E₂): a randomized clinical trial in girls with Turner syndrome

CONTEXT

The long-term effects of pure 17β-estradiol (E₂) depending on route of administration have not been well characterized.

OBJECTIVE

Our objective was to assess metabolic effects of oral vs transdermal (TD) 17β-E₂ replacement using estrogen concentration-based dosing in girls with Turner syndrome (TS).

PATIENTS

Forty girls with TS, mean age 16.7 ± 1.7 years, were recruited.

DESIGN

Subjects were randomized to 17β-E₂ orally or TD. Doses were titrated using mean E₂ concentrations of normally menstruating girls as therapeutic target. E₂, estrone (E₁), and E₁ sulfate (E₁S) were measured by liquid chromatography tandem mass spectrometry and a recombinant cell bioassay; metabolites were measured, and dual-energy x-ray absorptiometry scan and indirect calorimetry were performed.

MAIN OUTCOME

Changes in body composition and lipid oxidation were evaluated.

RESULTS

E₂ concentrations were titrated to normal range in both groups; mean oral dose was 2 mg, and TD dose was 0.1 mg. After 6 and 12 months, fat-free mass and percent fat mass, bone mineral density accrual, lipid oxidation, and resting energy expenditure rates were similar between groups. IGF-1 concentrations were lower on oral 17β-E₂, but suppression of gonadotropins was comparable with no significant changes in lipids, glucose, osteocalcin, or highly sensitive C-reactive protein between groups. However, E₁, E₁S, SHBG, and bioestrogen concentrations were significantly higher in the oral group.

CONCLUSIONS

When E₂ concentrations are titrated to the normal range, the route of delivery of 17β-E₂ does not affect differentially body composition, lipid oxidation, and lipid concentrations in hypogonadal girls with TS. However, total estrogen exposure (E₁, E₁S, and total bioestrogen) is significantly higher after oral 17β-E₂. TD 17β-E₂ results in a more physiological estrogen milieu than oral 17β-E₂ administration in girls with TS.

Skeletal muscle abnormalities in girls and adolescents with Turner syndrome

CONTEXT

Turner syndrome (TS) is a chromosomal disorder occurring in approximately 1 in 2500 live births. Individuals with TS report lower levels of physical activity than healthy control (HC) subjects. Cardiorespiratory limitations may contribute to the observed reduction in physical activity.

OBJECTIVE

The objective of this study was to compare muscle metabolism of patients with TS vs HC subjects before and after exercise using exercise testing, magnetic resonance imaging, and magnetic resonance spectroscopy techniques.

DESIGN

We hypothesized that girls and adolescents with TS would have muscle metabolic abnormalities not present in the HC population.

SETTING

The research was conducted at the Hospital for Sick Children in Toronto, Ontario, Canada.

PARTICIPANTS

Fifteen participants with TS were age-, activity-, and body mass index Z-score-matched with 16 HC subjects.

MAIN OUTCOME MEASURES

(31)P magnetic resonance spectroscopy was used to characterize muscle metabolism at rest and after 30 seconds of high-intensity exercise, 60 seconds of moderate-intensity exercise, and 5 minutes of low-intensity exercise.

RESULTS

While achieving the same workloads, participants with TS exhibited a greater difference between rest and end-exercise pH compared with HC subjects after 30 seconds (TS, 0.29 ± 0.04; HC, 0.21 ± 0.08; P = .03) and 90 seconds (TS, 0.47 ± 0.22; HC, 0.32 ± 0.13; P = .02) of exercise. During the 5-minute exercise test, similar workloads were achieved between groups; however, ATP production was greater in participants with TS vs the HC subjects via all 3 bioenergetic pathways (total ATP: TS, 0.90 ± 0.34; HC, 0.60 ± 0.25; P = .01).

CONCLUSIONS

The results of this study suggest that patients with TS exhibit greater anaerobic stress during exercise than HC subjects, which may lead to symptoms of increased muscle fatigue with short bursts of activity. Recovery metabolism after exercise appears to be similar between participants with TS and HC subjects, which is suggestive of normal mitochondrial metabolism and oxygen transport.

Reduced sebum production in Turner syndrome: a study of twenty-two patients

Turner's syndrome (TS) is a genetic disorder caused by numeric and/or structural abnormalities of the X chromosome. In a previous study it was observed that acne is less frequent in TS than in the general population. Since the onset of acne in pre-pubertal or pubertal age is related to sebum production, this study evaluates sebum secretion in TS patients, comparing the results with those of a control group of age-matched healthy female subjects. A total of 22 patients affected by TS (mean age 26.56±7.89 years) and a control group of 23 age-matched healthy females were studied. Sebum production was measured using a Sebumeter SM810. Mean sebum secretion in TS subjects was significantly lower than in the control group (81.35±66.44 UA vs 147.09±33.62 UA, p<0.001) and this significant difference was found in every facial zone. The reduction of sebum secretion may explain, using a simple and non-invasive method, the absence or the low incidence of acne in TS patients.

Metabolic and cardiovascular outcomes in a group of adult patients with Turner's syndrome under hormonal replacement therapy

OBJECTIVE

Turner's syndrome (TS) is a rare genetic disorder caused by complete or partial X chromosome monosomy in a phenotypic female, and it is associated with increased morbidity and mortality for cardiovascular diseases, impaired glucose tolerance, and dyslipidemia.

SUBJECTS AND METHODS

In 30 adult TS patients under chronic hormonal replacement therapy (HRT), 17β-estradiol (E(2)), body mass index (BMI), waist circumference, fasting glucose and insulin, homeostatic model assessment (HOMA) index, serum lipids, oral glucose tolerance test (OGTT), 24 h ambulatory blood pressure monitoring (ABPM), and intima-media thickness (IMT) were evaluated and compared with those in 30 age- and sex-matched controls (CS).

RESULTS

No difference was found between TS and CS in E(2) and BMI, whereas waist circumference was higher (P<0.05) in TS (77.7±2.5 cm) than in CS (69.8±1.0 cm). Fasting glucose in TS and in CS was similar, whereas fasting insulin, HOMA index, and 2 h glucose after OGTT were higher (P<0.0005) in TS (13.2±0.8 mUI/l, 2.5±0.2, and 108.9±5.5 mg/dl respectively) than in CS (9.1±0.5 mUI/l, 1.8±0.1, and 94.5 ± 3.8 mg/dl respectively). Total cholesterol was higher (P<0.05) in TS (199.4 ± 6.6 mg/dl) than in CS (173.9±4.6 mg/dl), whereas no significant differences in high-density lipoprotein, low-density lipoprotein, and triglycerides were found between the two groups. In 13% of TS, ABPM showed arterial hypertension, whereas IMT was <0.9 mm in all TS and CS. A negative correlation between insulin levels, HOMA index, or 2 h glucose after OGTT and E(2) was present in TS.

CONCLUSIONS

Our results indicate that adult patients with TS under HRT are connoted by higher frequency of central obesity, insulin resistance, hypercholesterolemia, and hypertension.

Bone geometry and volumetric bone mineral density in girls with Turner syndrome of different pubertal stages

OBJECTIVE

An increased rate of fractures has been reported in patients with Turner syndrome (TS). We aimed to assess bone geometry and volumetric bone mineral density (vBMD) at the radius in girls with TS and to evaluate the relationships between bone parameters and fracture history.

METHODS AND DESIGN

Sixty-seven girls with TS aged 6-19 years treated currently or in the past with growth hormone (GH) and/or oestrogens were examined using peripheral quantitative computed tomography. Results were compared to reference data.

RESULTS

Cortical area and cortical thickness were low in all age groups (all P<0·001). Height-adjusted total bone area at the diaphysis was increased in prepubertal and postpubertal girls (mean Z-score 1·0, P<0·05 for both) and normal in the pubertal group (mean Z-score 0·1). Cortical vBMD was decreased (mean age-specific Z-scores -2·0, -1·6 and -1·0 for prepubertal, pubertal and postpubertal groups, respectively, P<0·01 for all groups). Height- , age- and cortical thickness-adjusted cortical vBMD was positively correlated to the duration of GH therapy (P=0·012) and to oestrogen administration (P=0·047). Girls with a history of fractures had lower total vBMD at the metaphysis compared to nonfractured TS girls (mean Z-scores -1·7 vs-0·9, P=0·04).

CONCLUSIONS

There is a cortical bone deficit in girls with TS characterized by low cortical area, thin cortex and probably decreased cortical vBMD. Early commencement of GH therapy, as well as oestrogen replacement, is associated with higher cortical vBMD. Further studies should investigate the potential causality of this relation.

[Lipoprotein a (Lp(a)) in patients with Turner's syndrome]

INTRODUCTION

Women with Turner syndrome (TS) more frequently develop cardiovascular disease. Abnormal lipid metabolism is a well known risk factor for ischemic heart disease.

AIM OF THE STUDY

was to evaluate serum lipid abnormalities, particularly lipoprotein (a) (Lp(a)) in patients with TS.

MATERIAL AND METHODS

The study group consisted of 65 girls with TS without clinical signs of thyroid dysfunction or diabetes mellitus. The mean age was 12.45+/-5,03 (2-21) years. X chromosome monosomy was found in 60%, mosaicism in 30.8%, structural aberration in 9.2% of the patients. Most of them (59.7%) received GH treatment, 17.5 had finished treatment prior to the study, 22.8% did not start it yet. Height SDS, BMI SDS, Lp(a), cholesterol, triglycerides, free thyroxin, TSH, insulin, IGF-I, FSH, estradiol were determined.

RESULTS

Thyroid hormone values were within normal ranges in all the patients. In 30.1% (n=20) of them the diagnosis of Hashimoto disease had been established from 1 to 8 years prior to the trial, levothyroxine was administered and euthyreosis was observed. There were significant correlations between Lp(a) and cholesterol (r = 0.37, p=0.005) and Lp(a) and LDL (r=0.48, p<0.001), but not the age, height SDS, BMI SDS and other parameters. There were no significant differences in Lp(a) levels between the groups of patients with different karyotypes. The highest Lp(a) level was observed in patients before GH treatment, the lowest after finishing the treatment but without a statistical significance. We compared the groups of patients with high Lp(a) level (>35 mg/dl) (n=12) to low Lp(a) level (<5 mg/dl) (n=29), but did not find any difference in age, height, BMI, IGF1, insulin level. Only LDL concentration was significantly higher in the first group (p=0.036).

CONCLUSIONS

High Lp(a) concentration observed in 18.5% of patients with TS could lead to atherosclerotic process development. Ultrasound monitoring of arteries is therefore advisable. Lp(a) level does not seem to be influenced by karyotype, the age or auxological parameters. However, the evaluation of the influence of GH therapy requires further investigation.

X-chromosome gene dosage and the risk of diabetes in Turner syndrome

BACKGROUND

Turner syndrome (TS) is caused by the absence or fragmentation of the second sex chromosome. An increased risk of diabetes mellitus (DM) has consistently been noted, but the specific phenotype and genetic etiology of this trait are unknown.

METHODS

In a prospective study, we examined the prevalence of DM in adult participants in an intramural National Institutes of Health (NIH) TS study. Results were analyzed with respect to karyotype, age, body mass index (BMI), and autoimmune indices. Insulin sensitivity and secretion were compared in age- and BMI-matched euglycemic women with TS and healthy female controls. We compared gene expression profiles in lymphocytes from differentially affected TS groups.

RESULTS

Type 2 DM was present in 56 of 224 (25%) of the women with TS; type 1 DM was found in only one woman (<0.5%). DM was more prevalent among women with an isoXq chromosome compared to X monosomy (40.0 vs. 17.3%; P = 0.004). Euglycemic women with TS (n = 72; age, 33 +/- 12 yr; BMI, 23 +/- 3 kg/m(2)) had significantly higher glycemic and lower insulin responses to OGTT, with insulin sensitivity similar to controls. Gene expression profiles comparing 46,X,i(X)q vs. 45,X groups showed a significant increase in Xq transcripts and in potentially diabetogenic autosomal transcripts in the isoXq group.

CONCLUSION

Type 2 DM associated with deficient insulin release is significantly increased among women with monosomy for the X-chromosome but is increased even more among women with monosomy for Xp coupled with trisomy for Xq. These data suggest that haploinsufficiency for unknown Xp genes increases risk for DM and that excess dosage of Xq genes compounds the risk.

Long-term hormone replacement therapy preserves bone mineral density in Turner syndrome

CONTEXT

Reduced bone mineral density (BMD) and increased risk of fractures are present in many women with Turner syndrome (TS).

OBJECTIVE

Examine longitudinal changes in BMD in TS and relate changes to biochemical parameters.

DESIGN

Prospective, pragmatic, and observational study. Examinations at baseline and follow-up (5.9+/-0.7 years).

SETTING

Tertiary hospital.

PARTICIPANTS

Fifty-four women with TS (43.0+/-9.95 years). Interventions Hormone replacement therapy (HRT) and calcium and vitamin D supplementation. Main outcome measures BMD (g/cm(2)) measured at lumbar spine, hip, and the non-dominant forearm. Bone formation and resorption markers, sex hormones, IGF1, and maximal oxygen uptake.

RESULTS

At follow-up, forearm BMD, radius ultradistal BMD, and hip BMD remained unchanged, radius 1/3 BMD declined (0.601+/-0.059 vs 0.592+/-0.059, P=0.03), while spine BMD increased (0.972+/-0.139 vs 1.010+/-0.144, P<0.0005). Bone formation markers did not change over time in TS. Bone resorption markers decreased over time in TS. Testosterone, IGF1, and maximal oxygen uptake was significantly reduced in TS.

CONCLUSION

Longitudinal changes in BMD in TS were slight. BMD can be maintained at most sites in well-informed women with TS, being encouraged to maintain a healthy lifestyle, including HRT and intake of calcium and vitamin D.

A pilot study to evaluate gene expression profiles in peripheral blood mononuclear cells (PBMCs) from children with GH deficiency and Turner syndrome in response to GH treatment

Response to GH treatment is variable and dependent on diagnosis and dose. We used a pharmacogenomic approach to assess whether this variability is reflected in patterns of GH-induced gene expression in peripheral blood mononuclear cells (PBMCs) taken from three children with GH deficiency (GHD) and three girls with Turner syndrome (TS). Analysis of the response to GH treatment revealed that in GHD, 15 probe sets (11 genes) showed a fold change > +/- 1.4 at a P-value < 0.0005 (and a false detection rate <or= 15%). These genes included a suppressor of cytokine signalling (SOCS1) and a modulator of cAMP response elements (CREM). In marked contrast, in TS no genes fulfilled these criteria. ANOVA identified a subset of genes significantly affected by diagnosis, GH treatment or an interaction between diagnosis and treatment (P < 0.05, n = 2266). Cluster analysis indicated that genes up-regulated in both GHD and TS were related to DNA metabolism and transcription. Genes up-regulated in GHD but down-regulated in TS were involved in RNA processing and metabolism, whereas those down-regulated in GHD and up-regulated in TS were related to immune function. This pilot study has shown that major changes in gene expression in PBMCs can only be seen with confidence in GHD inferring that the pattern of gene expression in response to GH in GHD vs. TS is distinct and disease-specific. Further studies in larger cohorts will be required to evaluate whether GH-induced PBMCs gene expression patterns can predict responses to GH in a clinical setting.

[The role of inhibins in functions and dysfunctions of female reproduction. Part I]

The regulation of reproduction is performed by complex hormonal system: hypothalamus--pituitary--ovary. There are a lot of ovarian peptides, playing an essential role in the regulation of this system. However, the mechanisms of their action are not exactly known. Inhibins are glycoproteins produced mainly in the ovaries and they take part in the regulation of menstrual cycle. They consist of glycosylated alpha subunit and one of two beta subunits, inhibin A and inhibin B. There are studies about possible use of inhibins in reproductive medicine. Recent data indicate the role of inhibin A in obstetrics. The measurement of inhibin B can provide useful information about ovarian reserve, and plays an important role in assisted reproductive techniques. Inhibin B can be also regarded as potential marker of diagnosis of premature ovarian failure (POF) and ovarian recovery in hypothalamic disturbances. Both inhibin A and inhibin B can play helpful role in the assessment of ovarian function in patient with Turner syndrome. The estimation of total inhibin levels in blood serum seems to be advantageous in the diagnosis of patients with polycystic ovary syndrome (PCOS) and ovarian tumors. There are requirements of further studies to clarify the use of inhibins in clinical practice of reproductive endocrinology.

Puberty induction in Turner syndrome: results of oestrogen treatment on development of secondary sexual characteristics, uterine dimensions and serum hormone levels

BACKGROUND

Besides short stature, gonadal dysgenesis leading to a lack of oestrogen is one of the main characteristics of Turner syndrome (TS). In most TS girls, puberty is induced with exogenous oestrogens.

OBJECTIVE

To describe the pubertal development and uterine dimensions achieved by low-dose 17beta-oestradiol (17beta-E2) orally started at an appropriate age. Additionally, to determine whether serum hormone levels aid evaluation of pubertal progression.

DESIGN

In 56 TS girls, we prospectively studied pubertal stage, serum E2, LH, FSH, SHBG and oestrone (E1), starting oestrogen treatment with a low-dose 17beta-E2 (5 microg/kg/day) during GH treatment at mean (SD) age 12.7 (0.7) years. Hormone levels were measured at start, 3 months after start and after increasing 17beta-E2 dosage. Uterine dimensions were measured in 39 TS women at age 19.9 (2.2) years.

RESULTS

Although breast and pubic hair development were similar to that in normal Dutch girls up to Tanner stage B5 and P5, respectively, breast development was 2 years later. Before oestrogen therapy, E2 levels were comparable to those in prepubertal girls. With a 17beta-E2 dose of 5 microg/kg/day, these levels increased significantly, becoming comparable to normal late pubertal or adult concentrations, whereas SHBG levels were unchanged. At the adult 17beta-E2 dose, SHBG had increased significantly. Uterus shape was juvenile in four (10.2%), cylindrical in four and mature-adult shaped in 31 (79.5%) of TS patients.

CONCLUSIONS

During GH treatment in TS girls, normal breast development up to B5 can be mimicked, with just a 2-year delay. In a clinical setting, serum hormone levels provide no additional information for evaluating pubertal progression. After age-appropriate pubertal induction, uterine dimensions in women aged nearly 20 years were subnormal. It remains unclear whether this was related to E2 dosage, timing or duration, or factors related to TS.

Fracture risk and bone mineral density in Turner syndrome

Bone health is a major lifelong concern in caring for women and girls with Turner syndrome (TS). There is an approximately 25% increase in fracture risk most of which is related to medium or high impact trauma. The long bones, especially of the forearm are predominantly affected. This fact may be due to a selective cortical bone deficiency in TS which is unrelated to hypogonadism. In addition, lack of adequate estrogen replacement can lead to trabecular bone deficiency and increase in vertebral compression fractures after age 45. Evaluation of bone density by dual X-ray absorptiometry (DEXA) is important, however, it should be used judiciously in TS in view of its inherent tendency to underestimate the bone density of people with short stature. Bone size-independent methods, such as QCT or volumetric transformation of DEXA data should be used in individuals shorter than 150 cm. Achieving optimal bone density is of critical importance for fracture prevention in TS, and should be pursued by timely introduction of hormone replacement therapy, adequate dose of estrogens during the young adult life, optimal calcium and vitamin D intake and regular physical exercise. In addition, other measures to prevent fall and trauma should be considered, including optimizing hearing and vision, avoiding contact sports and exercise to improve coordination.

Metabolic effects of oral versus transdermal estrogen in growth hormone-treated girls with turner syndrome

BACKGROUND

Transdermal (TD) estrogen is often preferred over the oral route in postmenopausal and GH-deficient women taking estrogen, but this has not been studied in detail in girls.

OBJECTIVE

Our objective was to study the metabolic effects of oral vs. TD estrogen in GH-treated girls with Turner syndrome.

DESIGN AND METHODS

Eleven girls with Turner syndrome, mean age 13.4 +/- 0.5 (se) yr, on GH for at least 6 months were recruited. Studies included [(13)C]leucine and d5-glycerol infusions, indirect calorimetry, dual-emission x-ray absorptiometry, and hormone and substrate measurements. They received, in random order, 17beta-estradiol orally (0.5, 1, and 2 mg for 2 wk each) and TD (0.025, 0.0375, and 0.05 mg for 2 wk each), and studies were repeated after each 6-wk course with 4 wk washout in between.

RESULTS

Rates of whole-body protein turnover, oxidation and synthesis, lipolysis, lipid and carbohydrate oxidation, and resting energy expenditure were unaffected by either form of estrogen; nor were lipids, insulin, and fibrinogen concentrations affected. Plasma IGF-I concentrations did not change clinically significantly with either form of estrogen, despite higher estrogen concentrations after oral estrogen. Estradiol concentrations did not correlate with any variables measured.

CONCLUSIONS

In GH-treated girls with Turner syndrome, neither oral nor TD estrogen adversely affected rates of protein turnover, lipolysis, and lipid oxidation rates or plasma lipids, fibrinogen, or fasting insulin concentrations. There was no clinically significant change in IGF-I concentrations after either form of estrogen. In aggregate, these data suggest that the route of delivery of estrogen does not adversely affect these metabolic effects of GH in young girls with Turner syndrome.

Protein metabolism in Turner syndrome and the impact of hormone replacement therapy

BACKGROUND

Studies have documented an altered body composition in Turner syndrome (TS). Body fat is increased and muscle mass is decreased. Ovarian failure necessitates substitution with female hormone replacement therapy (HRT), and HRT induces favourable changes in body composition. It is unknown how HRT affects protein metabolism.

AIM

To test whether alterations in body composition before and after HRT in TS are a result of altered protein metabolism.

DESIGN

We performed a randomized crossover study with active treatment (HRT in TS and oral contraceptives in controls) or no treatment.

MATERIALS AND METHODS

We studied eight women (age 29.7 +/- 5.6 (mean +/- SD) years) with TS, verified by karyotype, and eight age-matched controls (age 27.3 +/- 4.9 years). All subjects underwent a 3-h study in the postabsorptive state. Protein dynamics of the whole body and of the forearm muscles were measured by an amino acid tracer dilution technique using [(15)N]phenylalanine and [(2)H(4)]tyrosine. Substrate metabolism was examined by indirect calorimetry.

RESULTS

Energy expenditure was comparable among TS and controls, and did not change during active treatment. Whole-body phenylalanine and tyrosine fluxes were similar in the untreated situations, and did not change during active treatment. Amino acid degradation and protein synthesis were similar in all situations. Muscle protein breakdown was similar among groups, and was not affected by treatment. Muscle protein synthesis rate and forearm blood flow did not differ among groups or due to treatment.

CONCLUSION

Protein metabolism in TS is comparable to controls, and is not affected by HRT.

Quantitative liver functions in Turner syndrome with and without hormone replacement therapy

BACKGROUND

Studies have documented elevated levels of liver enzymes in many females with Turner syndrome (TS). Histology has shown a range of changes. Treatment with female hormone replacement therapy (HRT) reduces liver enzymes.

AIM

To study quantitative liver functions in TS in detail with and without HRT.

DESIGN

Randomized crossover study with active treatment (HRT in TS and P-pill in controls) or no treatment.

SUBJECTS

Women with TS (n = 8, age 29.7 +/- 5.6 (mean +/- s.d.) years), verified by karyotype, and age-matched controls (C; n = 8, age 27.3 +/- 4.9 years).

METHODS

We determined liver enzymes in blood, used the galactose elimination capacity to assess hepatocyte cytosol activity, plasma clearance of indocyanine green to assess excretory function, antipyrine clearance to estimate microsomal activity, and the functional hepatic nitrogen clearance (FHNC) to assess mitochondrial-cytosolic metabolic capacity for conversion of amino-nitrogen.

RESULTS

Liver enzymes were elevated in untreated TS and reduced by HRT. The hepatic capacities for conversion of galactose, indocyanine green, and antipyrine were normal and did not change by HRT. The FHNC was marginally reduced (untreated TS vs C: 19.4 +/- 5.4 vs 25.2 +/- 7.3 L/h, P = 0.1). FHNC changed slightly with HRT in TS (19.4 +/- 5.4 vs 24.4 +/- 10.2 L/h, P = 0.2).

CONCLUSIONS

The elevations of liver enzymes in untreated TS are readily suppressed by HRT. Quantitative liver functions in TS are comparable to controls and are not affected by HRT.

First Trimester Down’s Syndrome Screening Shows High Detection Rate for Trisomy 21, but Poor Performance in Structural Abnormalities – Regional Outcome Results

OBJECTIVE

To evaluate whether first trimester screening markers are altered in pregnancies affected both by other chromosomal defects than trisomy 21 and structural anomalies and whether it is possible to detect these pregnancies by combined ultrasound and biochemical screening test.

METHODS

Altogether 4,776 singleton pregnancies underwent first trimester screening. Of them, 3,101 women were screened using a combination of maternal serum free hCG, pregnancy-associated plasma protein A and nuchal translucency and 1,361 women with first trimester biochemistry without ultrasound. Nuchal translucency screening was performed between the 11th and 13+6th gestational weeks, and biochemistry 1-2 weeks earlier.

RESULTS

Using a fixed cut-off rate of 1:250 for Down's syndrome, the detection rate of trisomies 21, 18 and 13 were 92, 67 and 0%, respectively. All open defects, 85% of cardiac defects and other minor defects were not detected in first trimester screening. Majority of these structural abnormalities occurred in women under 35 years of age.

CONCLUSION

First trimester Down's syndrome screening is effective in trisomy screening, but its performance in structural abnormalities is low, when used as a part of routine clinical practice. We conclude that it is too early to drop second trimester screening ultrasound entirely from antenatal care programs if a high detection rate is to be achieved also in structural defects.

No evidence for angiotensin type 2 receptor gene polymorphism in intron 1 in patients with coarctation of the aorta and Ullrich-Turner syndrome

In male patients with congenital anomalies of the kidney and urinary tract, an increased incidence of a polymorphism in the angiotensin type 2 receptor gene (AT2R) has been identified. The AT2R has been shown to be involved in apoptosis, particularly during embryogenesis. The aim of this study was to examine the A-->1675G transition polymorphism in intron 1 of the AT2R gene that is located on the X chromosome in patients with coarctation of the aorta (CoA) with and without Ullrich-Turner syndrome (UTS). Screening of DNA samples was performed with restriction fragment length polymorphism analysis. Ninety-seven patients with CoA, 28 girls with UTS, 10 girls with UTS and CoA, and 96 control individuals were studied. There was no significant difference in the distribution of A and G-genotypes in any of the patient groups compared to controls. An A-->1675G transition in the AT2R gene seems not to be involved in the pathogenesis of aortic coarctation.

Undetectable salivary testosterone in young women with premature ovarian failure

BACKGROUND

The extent of androgen deficiency in young women with premature ovarian failure (POF) is unclear.

AIM

Cross-sectional study of androgen status in young women with POF.

PATIENTS

Twenty women with POF: six had Turner syndrome (group A); eight had iatrogenic POF either secondary to bilateral oophorectomy or treatment of malignancy (group B); and six had idiopathic POF (group C). The median age was 30.5 years (range 19-39); in groups B and C the median duration of ovarian failure was 10.0 years (range 1-35).

METHODS

After a 2-month wash-out period without sex steroid replacement (SSR), serum testosterone (T), androstenedione (A4), dehydroepiandrosterone (DHEAS), SHBG, salivary testosterone (SalT) and the free androgen index [FAI = (serum T/SHBG) x 100] were measured.

RESULTS

Median serum A4 was 4.6 nmol/l (10th, 90th centiles, 3.6, 5.1) and DHEAS was 3.2 micromol/l (10th, 90th centiles, 2.3, 9.3). Although median serum T was relatively low at 1.4 nmol/l (10th, 90th centiles, 1.1, 1.7), median SHBG was also low at 34 nmol/l (10th, 90th centiles 22.2, 67.5) and the median calculated FAI was within the normal range at 3.7 (10th, 90th centiles, 2.3, 7.0). However, SalT was undetectable in almost all subjects in the three groups of POF.

CONCLUSIONS

Serum T and SHBG are relatively low in young women with POF and their FAI is therefore within the normal range. However, SalT, which measures free testosterone, is consistently low to undetectable in these young women with POF. The reliability of the FAI as a marker of androgen deficiency remains questionable.

Estrogen and hearing: a summary of recent investigations

Is the female sex steroid estrogen the key to preserved hearing in the aging human? This question remains unanswered, but hearing loss is more profound in elderly males than females. There are also well-known sex differences in the auditory brainstem response (ABR), i.e. women have shorter latencies than men. Moreover, menopausal women who are administered hormone replacement therapy have slightly better hearing than those who are not, and women with Turner's syndrome (45,X), who are biologically estrogen-deficient, show longer ABR latencies and early presbyacusis. These findings are also supported by animal experiments. When boosted with estrogen or testosterone the non-reproductive female midshipman fish alters its inner ear auditory mechanism so that it can hear the male's hum-like call. If estrogen receptor beta is knocked out in mice, severe progressive hearing loss occurs, leading to early deafness. In apparent contradiction to these findings, there have been case reports suggesting that hormone replacement therapy and oral contraceptive use can lead to hearing loss, but of another type, namely acute sudden deafness. Such contradictory aspects of the action of estrogen are commonly found and may spring from the fact that there are two estrogen receptors, alpha and beta, both of which are present in the inner ear of mice, rats and humans. Knowing how sex steroids can alter hearing ability may give important clues as to how estrogen can preserve hearing in humans. In this review we present a summary of current knowledge about hearing and estrogen.

The abnormalities of carbohydrate metabolism in Turner syndrome: analysis of risk factors associated with impaired glucose tolerance

An oral glucose tolerance test (OGTT) was performed in 103 patients with Turner syndrome (TS) who had normal fasting and postprandial glucose levels. The plasma glucose, insulin, C-peptide and proinsulin levels were measured every 30 min during the test. Using a homeostatic model assessment (HOMA) and a quantitative insulin sensitivity check index (QUICKI), the insulin resistance in TS patients was investigated. Diabetes mellitus and impaired glucose tolerance (IGT) were newly diagnosed in two and 18 patients respectively. There was a significant increase in mean plasma glucose, insulin, C-peptide and proinsulin response during an OGTT in the IGT group in contrast to the normal glucose tolerance (NGT) group ( P < 0.05). There was a significant decrease in the quantitative insulin sensitivity check index (QUICKI) in the IGT group in contrast to the NGT group ( P < 0.05). The fasting insulin and triglyceride levels strongly predicted the 2 h glucose level during the OGTT ( P < 0.05).

CONCLUSION

The oral glucose tolerance test is superior to the fasting and postprandial plasma glucose test for the early detection of abnormalities of carbohydrate metabolism in patients with Turner syndrome.

Adipokine dysregulation in turner syndrome: comparison of circulating interleukin-6 and leptin concentrations with measures of adiposity and C-reactive protein

Women with Turner syndrome (TS) have increased risks of atherosclerosis, diabetes mellitus, and obesity. We hypothesized that women with TS have adverse metabolic or inflammatory markers for cardiovascular disease compared with normal women and estrogen-deficient controls. This was a cross-sectional study conducted at University College London Hospitals, UK. One hundred seventeen estrogen-treated women with TS and normal fasting blood glucose were compared with 30 age-matched normal controls and 31 estrogen-treated women with 46,XX premature ovarian failure (POF). The main outcome measures were markers of the metabolic syndrome, including the adipokines IL-6 and leptin, and C-reactive protein (CRP). TS women were more obese than controls (waist circumference, 79.9 +/- 12.4, 73.5 +/- 6.9, and 74.7 +/- 8.6 cm in TS, normal subjects, and POF controls, respectively; P = 0.005; body mass index, 26.8 +/- 5.8, 23.7 +/- 3.2, and 22.9 +/- 3.4 kg/m2; P < 0.001). This obesity was associated with increased CRP (2.9 +/- 1.5, 0.8 +/- 1.0, and 1.2 +/- 0.9 mg/liter; P < 0.001) and IL-6 concentrations (1.5 +/- 0.7, 1.0 +/- 1.5, and 1.2 +/- 0.5 pg/ml; P = 0.014), but lower fasting serum insulin (4.7 +/- 2.3, 6.3 +/- 3.0, and 6.9 +/- 2.9 mIU/ml; P = 0.004), glucose (83 +/- 11, 90 +/- 7, and 90 +/- 7 mg/dl; P < 0.001), and leptin (10.2 +/- 6.3, 14.4 +/- 7.6, and 14.8 +/- 8.1 ng/ml; P = 0.048). Triglyceride concentrations were similar in TS and POF women and were greater than in normal controls (97 +/- 53, 97 +/- 53, and 71 +/- 27 mg/dl; P = 0.024). We conclude that women with TS have various physical and biochemical features suggestive of the metabolic/insulin resistance syndrome, but there is a discrepancy among CRP, IL-6, and leptin, with leptin and fasting insulin concentrations being lower than expected for the degree of obesity. Obesity and estrogen therapy do not fully explain these findings. Women with TS may have specific metabolic defects contributing to cardiovascular risk.

Excess visceral and hepatic adipose tissue in Turner syndrome determined by magnetic resonance imaging: estrogen deficiency associated with hepatic adipose content

Obesity, predominantly centrally distributed, is common in women with Turner syndrome (TS) and is thought to contribute to the increased risk of atherosclerosis; however, insulin concentrations are unexpectedly low. To explore this discrepancy, we assessed fat content and distribution by magnetic resonance imaging (MRI) and bioelectrical impedance (BI). Six nondiabetic, estrogen-treated women with TS were compared with six age-matched normal controls of similar body mass index. Clinical history, anthropometric measurements, biochemical markers, and MRI and BI measures of adiposity were assessed. TS women had increased intrahepatocellular lipids (IHCL) on MRI. After height adjustment, they also had an excess of total and visceral compared with sc adipose tissue (AT) than controls, without elevated insulin concentrations. BI and MRI measures correlated strongly for total and sc, but not visceral, AT in TS. IHCL was associated with cumulative estrogen-deficient years (r = 0.928; P = 0.008). Women with TS depart from the classical picture of metabolic syndrome despite an excess of total and visceral AT on MRI. Elevated IHCL in TS is associated with estrogen deficiency. BI may be useful to estimate total body fat, but does not reliably localize fat depots in TS.

[Evaluation of insulin resistance and lipid profile in turner syndrome]

OBJECTIVE

To evaluate the presence of insulin resistance (IR) and changes in lipid profile in Turner Syndrome (TS), and to check the influence of age, karyotype, systemic arterial hypertension (SAH), height, weight, body mass index (BMI), and pubertal development.

PATIENTS AND METHODS

A transversal study of 35 TS patients, confirmed with karyotype (5 to 43 years), without previous use of anabolic steroid or hGH, with evaluation of blood pressure, pubertal development, anthropometric data, measurement of waist (W), hip (H), W to H ratio, total cholesterol, HDL, triglycerides (TGC), LDL, insulin and glucose. HOMA and QUICKI indexes were calculated, as well as glucose to insulin ratio (G/I). Data were examined by the Mann-Whitney and Spearman tests.

RESULTS

Ten patients were >20 years. Seventeen had a 45,X karyotype and 6 structural aberrations; differences of the variables in relation to the karyotypes were not observed; 15 were nonpubertal and 20 pubertal; TGC and HOMA were significantly higher in puberty, while G/I was lower. Seven had normal height, 8 had BMI >25 Kg/m2 (6 between 25 and 30, and 2 >30), and 19 W/H >0.85. Cholesterol levels were 180 +/- 42mg% (4 >240); HDL 57 +/- 16mg%; LDL 99 +/- 34 mg%; TGC 108 +/- 96 mg% (2 >200); HOMA 1.01 +/- 0.71; QUICKI 0.4 +/- 0.04 and G/I 23.5 +/- 12.1 (2 <7.0).

CONCLUSIONS

Changes were observed in lipid profile independent of age, karyotype, SAH and obesity, but associated with IR. The frequency of IR was lower than described in literature, and seems to be directly linked to chronological age, obesity and estrogen therapy.

Epidemiological, endocrine and metabolic features in Turner syndrome

Turner syndrome is one of the more common genetic disorders, associated with abnormalities of the X chromosome, and occurring in about 50 per 100,000 liveborn girls. Turner syndrome is usually associated with reduced adult height, gonadal dysgenesis, and thus insufficient circulating levels of female sex steroids, and infertility. A number of other signs and symptoms are seen more frequent with the syndrome. Morbidity and mortality is increased. The average intellectual performance is within the normal range. With respect to epidemiology, cardiology, endocrinology and metabolism a number of recent studies have allowed new insight. Treatment with GH during childhood and adolescence allows a considerable gain in adult height. Puberty has to be induced in most cases, and female sex hormone replacement therapy is given during adult years. The proper dose of HRT has not been established, and, likewise, benefits and/or drawbacks from HRT has not been thoroughly evaluated. Since the risk of cardiovascular and endocrinological disease is clearly elevated, proper care during adulthood is emphasized. In summary, Turner syndrome is a condition associated with a number of disease and conditions which are reviewed in present paper.

[Carbohydrate metabolism in patients with Turner syndrome. The effect of therapy with growth hormone, oxandrolone and a combination of both]

Insulin resistance or the impairment of insulin capability to decrease blood glucose levels is seen in approximately 25% of girls with Turner syndrome (TS). Growth hormone (hGH), especially when administered at pharmacological doses, may additionally negatively affect the carbohydrate metabolism in TS girls, changing the response of peripheral tissues to insulin. The aim of the report was the assessment of glucose and insulin release and the prevalence of insulin resistance in physiological conditions (baseline and post-standard meal values), as well as after oral and IV glucose tolerance test in patients with Turner syndrome after a 6-month therapy with growth hormone, oxandrolone (Ox) and a combination of these two agents (hGH+Ox). The authors also evaluated the effect of these three therapeutic methods on carbohydrate metabolism, attempting to define the risk of glucose intolerance, type 2 diabetes and hyperinsulinemia and insulin resistance. The analysis of individual results in all the patients revealed that laboratory criteria for diagnosis type 2 diabetes (glycemia at 120 min OGTT >12.2 mmol/l) were met by one patient subjected to a combined therapy. Glucose intolerance (IGT) in OGTT, normally seen in 12.5% of untreated girls, was not intensified following a 6-month hGH or Ox therapy, but was more pronounced in patients on the combined treatment. A tendency was seen towards fasting hyperinsulinism (>25 uLI/ml) in patients on hGH and hGH+Ox, with more pronounced insulin resistance (IR1<7, IR2>5) in girls on the combined therapy.

CONCLUSIONS

Combined treatment with growth hormone and oxandrolone results in a significant increase of insulin secretion and increased insulin resistance. In view of the effects of insulin resistance, one should analyze the advisability of combined treatment with growth hormone and oxandrolone in girls with Turner syndrome.

The pituitary in Turner syndrome

Although Turner syndrome is not uncommon, studies of the pituitary in this condition are few. We undertook a histochemical and immunohistochemical study of four cases. As expected, "gonadal failure cells" were seen, but without recognizable gonadotroph hyperplasia. No gonadotroph adenomas were encountered. Instead, three silent corticotroph microadenomas were seen; their etiology remains unexplained. The question of whether the simultaneous occurrence of Turner syndrome and silent corticotroph adenoma is causal or incidental cannot be answered on the basis of the study of our material. Because these two diseases are rare, an etiologic association has to be considered. For example, it is possible that (a) protracted stimulation of gonadotrophs leads to transdifferentiation to corticotrophs, a hypothesis supported by the fact that normal and neoplastic gonadotrophs can contain ACTH and that some corticotroph adenomas produce LH and/or alpha subunit, (b) corticotrophs develop gonadotropin-releasing hormone (GnRH) receptors and undergo neoplastic transformation when exposed to continuous elevation of GnRH, FSH, and/or LH levels, and (c) the genetic defect in Turner syndrome promotes the formation of corticotroph adenomas.

Epidemiological, endocrine and metabolic features in Turner syndrome

Turner syndrome is one of the more common genetic disorders, associated with abnormalities of the X chromosome, and occurring in about 50 per 100 000 liveborn girls. Turner syndrome is usually associated with reduced adult height, gonadal dysgenesis and thus insufficient circulating levels of female sex steroids, and infertility. A number of other signs and symptoms are seen more frequently with the syndrome. Morbidity and mortality are increased. The average intellectual performance is within the normal range. A number of recent studies have provided new insights with respect to epidemiology, cardiology, endocrinology and metabolism. Treatment with GH during childhood and adolescence allows a considerable gain in adult height, although very-long-term consequences of this treatment are not clear. Puberty has to be induced in most cases, and female sex hormone replacement therapy is given during the adult years. The proper dose of hormone replacement therapy (HRT) has not been established, and, likewise, benefits and/or drawbacks from HRT have not been thoroughly evaluated. Since the risk of cardiovascular and endocrinological disease is clearly elevated, proper care during adulthood is emphasized. In summary, Turner syndrome is a condition associated with a number of diseases and conditions which are reviewed in the present paper.

Oestrogen Deficiency and Growth Hormone Treatment in Childhood Are Not Associated with Hearing in Adults with Turner Syndrome

BACKGROUND/AIMS

Women with Turner syndrome (TS) have an increased prevalence of hearing loss, with conductive (CHL) and sensorineural (SNHL) components. The association between hearing loss and clinical parameters, particularly oestrogen and previous growth hormone (GH) treatment, was investigated.

METHODS

A cross-sectional study of pure tone audiometry tests in an adult TS population. Previous ENT history, karyotype, anthropomorphic measurements and the impact of oestrogen and childhood GH therapy were assessed. One hundred and thirty-eight women (median age 29, range 16-67 years) completed the study.

RESULTS

Normal hearing was found in 20.3% of women, CHL in 18.8%, SNHL in 57.2% and confounding factors in 3.6%. Neither CHL nor SNHL were associated with oestrogen deficiency or GH treatment independent of age. CHL but not SNHL was more common in those with a history of recurrent otitis media (p < 0.01) and monosomy 45,X (p < 0.01).

CONCLUSIONS

Current regimens of oestrogen and GH therapy have no impact on adult hearing loss in TS, independent of age. The prevalence of SNHL increases with age. CHL but not SNHL is associated with ENT history and karyotype. According to present evidence, the only possible intervention to reduce hearing loss in women with TS remains assiduous treatment of ENT problems in childhood.