Reference values for body proportions and body composition in adult women with Ullrich-Turner syndrome

Transition from pediatric to adult care in patients with Turner syndrome in Italy: a consensus statement by the TRAMITI project

PURPOSE

Transition from pediatric to adult care is associated with significant challenges in patients with Turner syndrome (TS). The objective of the TRansition Age Management In Turner syndrome in Italy (TRAMITI) project was to improve the care provided to patients with TS by harnessing the knowledge and expertise of various Italian centers through a Delphi-like consensus process.

METHODS

A panel of 15 physicians and 1 psychologist discussed 4 key domains: transition and referral, sexual and bone health and oncological risks, social and psychological aspects and systemic and metabolic disorders.

RESULTS

A total of 41 consensus statements were drafted. The transition from pediatric to adult care is a critical period for patients with TS, necessitating tailored approaches and early disclosure of the diagnosis to promote self-reliance and healthcare autonomy. Fertility preservation and bone health strategies are recommended to mitigate long-term complications, and psychiatric evaluations are recommended to address the increased prevalence of anxiety and depression. The consensus also addresses the heightened risk of metabolic, cardiovascular and autoimmune disorders in patients with TS; regular screenings and interventions are advised to manage these conditions effectively. In addition, cardiac abnormalities, including aortic dissections, require regular monitoring and early surgical intervention if certain criteria are met.

CONCLUSIONS

The TRAMITI consensus statement provides valuable insights and evidence-based recommendations to guide healthcare practitioners in delivering comprehensive and patient-centered care for patients with TS. By addressing the complex medical and psychosocial aspects of the condition, this consensus aims to enhance TS management and improve the overall well-being and long-term outcomes of these individuals.

Body proportions in patients with Turner syndrome on growth hormone treatment

BACKGROUND

: In this cross-sectional study, we aimed to evaluate auxological measurements and detailed body proportions of recombinant human growth hormone (GH)-treated patients with Turner syndrome (TS) and compare them with a group of healthy females.

METHODS

We evaluated 42 patients with TS who received GH treatment and 20 healthy controls. Anthropometric measurements were taken and target height, body mass index (BMI), arm span-height difference, extremity-to-trunk ratio, and Manouvrier's skelic index were calculated.

RESULTS

: The median (min-max) age of the patients at the time of evaluation was 13.6 (4.3-20.7) years, and the control group was 12.9 (3.8-23.7) years. Height, sitting height, and arm span of TS patients were significantly lower than those of the control group. Sitting height/height ratio (SHR) was in normal ranges in both groups and BMI was significantly higher in TS patients when compared to the control group. According to Manouvrier's skelic index, TS patients had shorter legs than the control group (p = 0.001). The extremity-trunk ratio was significantly decreased in TS patients compared to healthy controls (p < 0.001). There was no significant difference between the karyotype groups in terms of these indexes.

DISCUSSION

TS patients had short stature, increased BMI and waist circumference, normal head circumference, and decreased extremity-trunk ratio. Sitting height and leg length were short; however, the SHR standard deviation score (SDS) was in the normal range. Despite being treated with GH, TS patients had disproportionate short stature. The disproportion in TS patients was similar to short-stature homeobox-containing gene (SHOX) deficiency, which is considered to be SHOX haploinsufficiency in the etiopathogenesis of short stature.

Hyperglycemia in Turner syndrome: Impact, mechanisms, and areas for future research

Turner syndrome (TS) is a common chromosomal disorder resulting from complete or partial absence of the second sex chromosome. Hyperglycemia, ranging from impaired glucose tolerance (IGT) to diabetes mellitus (DM), is common in TS. DM in individuals with TS is associated with an 11-fold excess in mortality. The reasons for the high prevalence of hyperglycemia in TS are not well understood even though this aspect of TS was initially reported almost 60 years ago. Karyotype, as a proxy for X chromosome (Xchr) gene dosage, has been associated with DM risk in TS - however, no specific Xchr genes or loci have been implicated in the TS hyperglycemia phenotype. The molecular genetic study of TS-related phenotypes is hampered by inability to design analyses based on familial segregation, as TS is a non-heritable genetic disorder. Mechanistic studies are confounded by a lack of adequate TS animal models, small and heterogenous study populations, and the use of medications that alter carbohydrate metabolism in the management of TS. This review summarizes and assesses existing data related to the physiological and genetic mechanisms hypothesized to underlie hyperglycemia in TS, concluding that insulin deficiency is an early defect intrinsic to TS that results in hyperglycemia. Diagnostic criteria and therapeutic options for treatment of hyperglycemia in TS are presented, while emphasizing the pitfalls and complexities of studying glucose metabolism and diagnosing hyperglycemia in the TS population.

Hypertension in Turner syndrome: a review of proposed mechanisms, management and new directions

Acquired cardiovascular diseases account for much of the increased risk of premature death in patients with Turner syndrome (TS). Hypertension is a major modifiable cardiovascular risk factor. It has a high prevalence in TS developing at an early age and thus leading to prolonged exposure to high blood pressure. The aetiology for hypertension in TS is largely unknown. It is likely multifactorial, and recent hypotheses include altered sympathetic tone, vasculopathy and endocrine factors. In this review article we aim to provide a comprehensive review of data on mechanisms of hypertension in TS and their implication for diagnostics and optimal choice of antihypertensive treatments. Ultimately this knowledge should help prevent hypertension-related complications, and improve quality of life and life expectancy for patients with TS.

The Changing Face of Turner Syndrome

Turner syndrome (TS) is a condition in females missing the second sex chromosome (45,X) or parts thereof. It is considered a rare genetic condition and is associated with a wide range of clinical stigmata, such as short stature, ovarian dysgenesis, delayed puberty and infertility, congenital malformations, endocrine disorders, including a range of autoimmune conditions and type 2 diabetes, and neurocognitive deficits. Morbidity and mortality are clearly increased compared with the general population and the average age at diagnosis is quite delayed. During recent years it has become clear that a multidisciplinary approach is necessary toward the patient with TS. A number of clinical advances has been implemented, and these are reviewed. Our understanding of the genomic architecture of TS is advancing rapidly, and these latest developments are reviewed and discussed. Several candidate genes, genomic pathways and mechanisms, including an altered transcriptome and epigenome, are also presented.

Paleopathological diagnosis of a proportionate short stature on a female skeleton from the Coimbra collection: Turner syndrome versus other causes

OBJECTIVE

This paper discusses the possible etiologies for the proportionate short stature of a female individual and provides data to allow the diagnosis of future cases of Turner Syndrome (TS) in paleopathology.

MATERIALS

Skeleton of a 26-years-old maid, from the Coimbra Identified Skeletal Collection, who died of measles in 1920.

METHODS

Macroscopic examination, imaging techniques, and metric analysis.

RESULTS

Her estimated height is 138.91-144.3 cm, approximately three standard deviations below the average female stature for early 20th century Portugal. The crural, brachial, humero-femoral, and intermembral indexes show a proportionate body, uncommon in dwarfism. Small skull with prominent frontal, maxillary prognathism, enamel hypoplasia, cribra orbitalia, porotic hyperostosis, proliferative reaction in the petrous portion of the temporal, obliterated sagittal suture, oval foramen magnum, and small mandible with masculine features. The sternal ends of the ribs are wider and vertebrae present developmental defects (e.g. atlas with both left transverse foramina and posterior tubercle open, absence of the right transverse foramen in the axis, sacrum with six vertebrae).

CONCLUSIONS

The differential diagnosis point to a possible case of Turner Syndrome.

SIGNIFICANCE

This study describes the features of Turner Syndrome and provide detail metric analysis of this individual, which will be useful for future paleopathological diagnoses.

LIMITATIONS

The confirmation of the diagnosis will only be possible through genetic analysis.

SUGGESTIONS FOR FURTHER RESEARCH

Reanalysis of skeletal individuals with short stature to detect possible cases of Turner Syndrome.

Skeletal disproportion in girls with Turner syndrome and longitudinal change with growth-promoting therapy

OBJECTIVE

Short stature in Turner syndrome (TS) may be accompanied by skeletal disproportion. This retrospective study investigates growth and disproportion from early childhood to adult height.

STUDY DESIGN

Data were collected from 59 girls prior to growth hormone (rhGH) treatment and in 30 girls followed up longitudinally. Standard deviation scores (SDS) for height (Ht), sitting height (SH) and sub-ischial leg length (LL) were compared and a disproportion score (SH SDS - LL SDS) calculated.

RESULTS

In 59 girls, mean (SD) age 6.6 (2.1) years prior to rhGH treatment, LL SDS of -3.4 (1.1) was significantly lower than SH SDS of -1.2 (0.8) [p < .001]. In girls with Ht SDS < -2.0, disproportion score was > +2.0 in 27 (63%), cf eight (50%) with Ht SDS ≥ -2.0. For the longitudinal analysis, skeletal disproportion prior to rhGH was +2.4 (1.1) and +1.7 (1.0) on rhGH but prior to introduction of oestrogen [p < .001]. Disproportion at adult height was +1.1 (0.8), which was less marked than at the earlier time points [p < .001 for both comparisons]. Change in disproportion SDS over the first two years of rhGH predicted overall change in disproportion from baseline to adult height [R² 51.7%, p < .001].

CONCLUSION

TS is associated with skeletal disproportion, which is more severe in the shortest girls and present in only half of those with milder degrees of short stature. Growth-promoting therapy may improve disproportion during both the childhood and pubertal phases of growth. Change in disproportion status two years after starting rhGH helps predict disproportion at adult height.

Disproportion and dysmorphism in an adult Belgian population with Turner syndrome: risk factors for chronic diseases?

BACKGROUND

Turner syndrome (TS) is characterized by dysmorphism and body disproportion. TS women are also susceptible to a range of chronic disorders including arterial hypertension (AHT), osteoporosis, sensorineural hearing loss (SNHL), type 2 diabetes mellitus (DM2) and thyroid disease. The association between dysmorphism/body disproportion and chronic disease has never been studied in TS women. The effect of growth hormone treatment on body disproportion is also unclear. Objectives: to analyze dysmorphic features and body disproportion in TS women in relation to the presence of chronic disease and to document the effect of growth hormone therapy on body disproportion.

METHOD

76 adult TS women with a regular follow up at the TS clinic UZ Ghent were invited to participate. Detailed body measurements were performed in 44 volunteering TS women. Scoring systems for overall dysmorphism, craniofacial dysmorphism, thoracic and limb abnormalities and skeletal disproportion were developed.

RESULTS

TS women with a higher dysmorphism score were more at risk for AHT (p = 0.04) as well as those with a higher sitting height/standing height ratio (p < 0.05). Prevalence of AHT, osteoporosis and DM 2 was lower in TS women treated with GH during childhood (p < 0.05).

CONCLUSIONS

Adult TS women with relatively short legs or with more physical dysmorphic stigmata were more at risk for AHT. GH therapy does not seem to increase the risk of chronic disease on the long term.

Turner syndrome: mechanisms and management

Turner syndrome is a rare condition in women that is associated with either complete or partial loss of one X chromosome, often in mosaic karyotypes. Turner syndrome is associated with short stature, delayed puberty, ovarian dysgenesis, hypergonadotropic hypogonadism, infertility, congenital malformations of the heart, endocrine disorders such as type 1 and type 2 diabetes mellitus, osteoporosis and autoimmune disorders. Morbidity and mortality are increased in women with Turner syndrome compared with the general population and the involvement of multiple organs through all stages of life necessitates a multidisciplinary approach to care. Despite an often conspicuous phenotype, the diagnostic delay can be substantial and the average age at diagnosis is around 15 years of age. However, numerous important clinical advances have been achieved, covering all specialty fields involved in the care of girls and women with Turner syndrome. Here, we present an updated Review of Turner syndrome, covering advances in genetic and genomic mechanisms of disease, associated disorders and multidisciplinary approaches to patient management, including growth hormone therapy and hormone replacement therapy.

Glucose Metabolism in Turner Syndrome

Turner syndrome (TS) is one of the most common female chromosomal disorders. The condition is caused by complete or partial loss of a single X chromosome. Adult patients with TS have a high prevalence of diabetes mellitus (DM). Deranged glucose metabolism in this population seems to be genetically triggered. The traditional risk factors for DM in the general population may not play a major role in the pathogenesis of DM in patients with TS. This review focuses on the latest research studies pertaining to abnormalities of glucose metabolism in TS. We extensively review the available evidence pertaining to the influence of insulin secretion and sensitivity, obesity, autoimmunity, lifestyle, growth hormone, and sex hormone replacement therapy on the occurrence of DM in these patients.

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.

Increased arterial stiffness in young normotensive patients with Turner syndrome: associations with vascular biomarkers

OBJECTIVES

Factors contributing to arteriopathy in patients with Turner syndrome (TS) remain unclear. We assessed arterial stiffness in young, normotensive patients with TS and correlated arterial stiffness with vascular biomarkers, GH treatment and oestrogen exposure. Sixty-one patients with TS (mean age, 12·6 years; range 6·6-21·3 years) were matched for age and sex with 61 healthy peers. Associations between arterial stiffness and high-sensitivity C-reactive protein (hsCRP), B-type natriuretic peptide (BNP), atrial NP (ANP), plasma aldosterone/plasma renin activity (PRA), IGF1 and IGFBP3 were examined after adjusting for well-established confounders of vascular disease.

RESULTS

Carotid intima media thickness standard deviation score (SDS), arterial stiffness index SDS and incremental modulus of elasticity SDS were higher, and distensibility coefficient SDS was lower in patients with TS. The duration of GH treatment and oestrogen exposure was not associated with indices of arterial stiffness. TS patients had higher hsCRP, BNP and ANP. Plasma aldosterone/PRA, IGF1 and IGFBP3 were similar in patients and controls. Multivariable regression analyses (R(2) = 0·200-0·668, P < 0·01) showed that BNP was associated with all indices of arterial stiffness. We found that hsCRP was associated with distensibility coefficient SDS (β = -0·16, P < 0·01). TS was independently associated with increased arterial stiffness (β = 0·420-3·424, P < 0·001 for all, R(2) = 0·06-0·31).

CONCLUSIONS

Young, normotensive TS patients had increased arterial stiffness than that of healthy peers. BNP, and possibly hsCRP, was independently associated with arterial stiffness in TS. Further research will determine any causal inference of these relationships.

Association of endogenous sex hormones with adipokines and ghrelin in postmenopausal women

CONTEXT

Sex hormones, adipokines, and ghrelin have been implicated in central control of appetite, energy homeostasis, maintenance of fat mass, and inflammation. Women tend to gain weight after menopause and adipose tissue is a major source of sex steroid postmenopause. Understanding the dynamics of these analytes are of particular importance in postmenopausal women, who are at greater risk for cardiometabolic diseases.

OBJECTIVES

This study sought to evaluate the associations of adipokines and ghrelin with sex hormone concentrations in postmenopausal women.

DESIGN

We conducted a cross-sectional analysis of baseline clinical trial data.

SETTING

The parent trial was conducted at a university clinical research facility.

PARTICIPANTS

Baseline data from 634 postmenopausal women participating in the Early vs Late Intervention Trial with Estradiol (ELITE). PARTICIPANTS had no history of chronic illness in the past 5 years and were not taking exogenous hormone therapy.

MAIN OUTCOME MEASURES

Serum levels of estrone (E1), total estradiol (E2), free estradiol (FE2), free testosterone (FT), total testosterone (T), and sex hormone-binding globulin (SHBG).

RESULTS

Adjusted for age, race, time since menopause, and body mass index (BMI), leptin concentrations were significantly positively associated with E1, E2, FE2, and FT and inversely associated with SHBG levels. Only the associations of adiponectin with FE2 (inverse) and SHBG (positive) remained significant after controlling for BMI. The inverse associations of adiponectin with E1, E2, and FT were substantially mediated by BMI. Associations of ghrelin with E1, E2, FE2, and SHBG were not independent of BMI. Waist-to-hip circumference ratio was not a mediator in any of the associations.

CONCLUSIONS

In postmenopausal women, leptin and adiponectin concentrations are substantially correlated with sex hormone and SHBG concentrations regardless of obesity status.

The sitting height/height ratio for age in healthy and short individuals and its potential role in selecting short children for SHOX analysis

AIMS

To determine the presence of abnormal body proportion, assessed by sitting height/height ratio for age and sex (SH/H SDS) in healthy and short individuals, and to estimate its role in selecting short children for SHOX analysis.

METHODS

Height, sitting height and weight were evaluated in 1,771 healthy children, 128 children with idiopathic short stature (ISS), 58 individuals with SHOX defects (SHOX-D) and 193 females with Turner syndrome (TS).

RESULTS

The frequency of abnormal body proportion, defined as SH/H SDS >2, in ISS children was 16.4% (95% CI 10-22%), which was higher than in controls (1.4%, 95% CI 0.8-1.9%, p < 0.001). The SHOX gene was evaluated in all disproportionate ISS children and defects in this gene were observed in 19%. Among patients with SHOX-D, 88% of children (95% CI 75-100%) and 96% of adults had body disproportion. In contrast, SH/H SDS >2 were less common in children (48%, 95% CI 37-59%) and in adults (28%, 95% CI 20-36%) with TS.

CONCLUSION

Abnormal body proportions were observed in almost all individuals with SHOX-D, 50% of females with TS and 16% of children considered ISS. Defects in SHOX gene were identified in 19% of ISS children with SH/H SDS >2, suggesting that SH/H SDS is a useful tool to select children for undergoing SHOX molecular studies.

An evaluation of early cardiometabolic risk factors in children and adolescents with Turner syndrome

BACKGROUND AND OBJECTIVES

Turner syndrome (TS) confers increased lifetime risk of type 2 diabetes mellitus and cardiovascular disease. We compared cardiometabolic risk factors and measures of subcutaneous, visceral adipose tissue and intra-myocellular lipid between young TS girls and an age- and BMI-standard deviation scores (SDS)-matched healthy female cohort.

PATIENTS AND METHODS

A cross-sectional cohort study was conducted at the Hospital for Sick Children, Toronto. Nineteen TS and 17 control girls (13.7 ± 2.5 vs 12.7 ± 3.4 years of age, respectively, P = 0.30). Multiple-sample oral glucose tolerance test with measurement of fasting insulin, LDL, HDL, triglycerides, adiponectin and highly sensitive C-reactive protein (hsCRP) was performed. Subcutaneous adipose tissue, visceral adipose tissue intramyocellular lipid levels evaluated by magnetic resonance techniques. Insulin secretion (IS), sensitivity (Si) and the insulin secretion-sensitivity index (ISSI-2) were calculated from oral glucose tolerance test data.

RESULTS

Five TS and no controls had impaired fasting glucose or impaired glucose tolerance; none had type 2 diabetes mellitus. Insulin sensitivity and insulin secretion were similar between groups; ISSI-2 was lower in TS (923.5 ± 307.3 vs 659.1 ± 387.3; P = 0.03). TS girls had higher blood pressure (82.5 ± 13.6 vs 73.5 ± 5.5 mmHg; P = 0.0146), waist circumference (76.0 ± 11.8 vs 65.9 ± 9.7; P = 0.0087) and subcutaneous adipose tissue (135.6 ± 88.6 vs 69.3 ± 59.9; P = 0.01) than controls. Visceral adipose tissue, intramyocellular lipid levels and adiponectin were not different between groups. TS girls also had higher triglycerides (1.1 ± 0.6 vs 0.7 ± 0.3; P = 0.003), total cholesterol (4.4 ± 0.7 vs 3.9 ± 0.4; P = 0.02) and hsCRP (2.0 ± 1.9 vs 0.8 ± 0.3; P = 0.01).

CONCLUSIONS

TS girls exhibit more cardiometabolic risk factors and reduced beta cell function compared with age- and BMI-SDS-matched girls. Increased awareness of early risk of type 2 diabetes mellitus and hypertension in TS girls is needed.

Sex hormone replacement in Turner syndrome

The cardinal features of Turner syndrome (TS) are short stature, congenital abnormalities, infertility due to gonadal dysgenesis, with sex hormone insufficiency ensuing from premature ovarian failure, which is involved in lack of proper development of secondary sex characteristics and the frequent osteoporosis seen in Turner syndrome. But sex hormone insufficiency is also involved in the increased cardiovascular risk, state of physical fitness, insulin resistance, body composition, and may play a role in the increased incidence of autoimmunity. Severe morbidity and mortality affects females with Turner syndrome. Recent research emphasizes the need for proper sex hormone replacement therapy (HRT) during the entire lifespan of females with TS and new hypotheses concerning estrogen receptors, genetics and the timing of HRT offers valuable new information. In this review, we will discuss the effects of estrogen and androgen insufficiency as well as the effects of sex HRT on morbidity and mortality with special emphasis on evidence based research and areas needing further studies.

Growth hormone effect on body composition in Turner syndrome

This study analyzes the body composition of young adult women with Turner syndrome (TS) either treated or not treated with recombinant human growth hormone (rhGH) and compares them with a group of healthy women. Fifty-two non-treated TS patients (23.0 ± 5.8 years), 30 treated with rhGH (21.5 ± 1.5 years), and 133 healthy young adult women (22.9 ± 3.2 years) were evaluated regarding height (H) and weight, body mass index (BMI), brachial perimeter and tricipital cutaneous fold (fat and lean areas at the arm), sitting height (SRH = sitting height/H × 100), leg length (leg/H), waist and hip circumferences (waist/hip), and bioimpedance (percentages of water, lean mass, and fat mass). Age at start of rhGH therapy varied from 7.8 to 15.1 years (10.0 ± 1.3 years), duration of treatment from 2.8 to 8.2 years (3.7 ± 1.5 years), and the mean dose was 0.42 mg/kg/w (from 0.32 to 0.50 mg/kg/w). Body composition (except height) did not differ between TS groups, but there were differences when compared to the control group: weight and sitting height were lower in TS patients; and BMI, SHR, and leg/H were higher. There was an association between all groups with regards to BMI, waist, SHR, and leg/H, but not in percentage of fat mass. SHR was positively correlated with BMI, waist, hip, and percentage of fat mass. This sample of TS patients (with and without rhGH therapy) did not differ in BMI or body composition. However, there were differences between patients with TS patients and normal healthy women. Regardless of rhGH therapy, TS patients should be monitored, particularly for sitting height, SHR, leg length, leg/H, and waist/hip.

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.

Effects of growth hormone on body proportions in Turner syndrome compared with non-treated patients and normal women

BACKGROUND

The majority of anthropometric assessments in Turner syndrome (TS) patients has focused on height.

AIM

To analyze body proportions in young adult TS patients either treated or not treated with rhGH, and to compare them with a group of age-matched healthy women.

SUBJECTS AND METHODS

Standing height, sitting height, weight, foot and leg lengths, arm span, head circumference, biliac and biacromial diameters were measured in 52 non-treated TS patients, 30 treated with rhGH and 133 healthy women.

RESULTS

Age at the start of rhGH therapy varied from 7.8 to 15.1 yr (10.0±1.3 yr), the duration of treatment from 2.8 to 8.2 yr (3.7±1.5 yr) and the mean recombinant human GH (rhGH) dose was 0.42 mg/kg/week (from 0.32 to 0.50 mg/kg/week). Nontreated patients did not show any difference in anthropometric variables when compared with the treated ones, except for hand length (p=0.02) and height (p=0.05), which were increased in the treated group. All anthropometric variables, except head circumference, were different when comparing TS patients (either treated or not) with age-matched healthy women.

CONCLUSION

Brazilian TS patients either treated or not with rhGH showed almost no differences in terms of their body proportions. This result is probably due to the late age at the start of treatment, and/or the short period of rhGH administration. Hand length was different between the groups, showing the importance of including the extremities in body proportion assessment during rhGH treatment of TS patients.

A specific bioelectrical impedance equation to predict body composition in Turner's syndrome

INTRODUCTION

Cardiovascular disease is one of the main causes for Turner syndrome (TS) mortality and the evaluation of its risk factors such as excess body fat and its distribution is considered one of the major aspects of the adult patient care.

OBJECTIVE

To develop and validate a specific bioelectrical impedance analysis (BIA) equation to predict body composition in TS patients.

SUBJECTS AND METHODS

Clinical and anthropometric data, dual-energy X-ray absorptiometry (DXA) for total fat-free mass (FFM) and BIA for resistance and reactance were obtained from 50 adult TS patients. Linear regression analysis was performed with multiple clinical and BIA data to obtain a predicting equation.

RESULTS

The equation developed to estimate FFM in adult TS patients showed great consistency with DXA, elevated correlation (r = 0.974) and determination (r(2) = 0.948) coefficients and an adequate standard error estimate (SEE = 1.52 kg).

CONCLUSIONS

The specific equation developed here allowed making an adequate FFM estimate in adult TS patients.

Reduced abdominal adiposity and improved glucose tolerance in growth hormone-treated girls with Turner syndrome

BACKGROUND

Individuals with Turner syndrome (TS) are at increased risk for impaired glucose tolerance and diabetes mellitus. It is unknown whether pharmacological GH treatment commonly used to treat short stature in TS alters this risk.

OBJECTIVE

Our objective was to compare adiposity and glucose tolerance in GH-treated vs. untreated girls with TS.

METHODS

In a cross sectional study, GH-treated girls with TS (n = 76; age 13.6 +/- 3.7 yr) were compared to girls with TS that never received GH (n = 26; age 13.8 +/- 3.5 yr). Protocol studies took place in the NIH Clinical Research Center from 2001-2006 and included oral glucose tolerance tests, body composition analysis by dual-energy x-ray absorptiometry, and abdominal fat quantification by magnetic resonance imaging. GH was not given during testing.

RESULTS

Total body fat (35 +/- 8 vs. 28 +/- 8%, P < 0.0001), sc abdominal fat (183 vs. 100 ml, P = 0.001), and intraabdominal fat (50 vs. 33 ml, P < 0.0001) were significantly greater in untreated girls. Fasting glucose and insulin were similar, but the response to oral glucose was significantly impaired in the untreated group (28 vs. 7% with impaired glucose tolerance, P = 0.006). A specific excess of visceral fat and insulin resistance was apparent only in postpubertal girls that had never received GH. GH-treated girls demonstrated lower adiposity compared with untreated girls for an average of 2 yr after discontinuation of GH.

CONCLUSIONS

Abdominal adiposity is significantly lower and glucose tolerance significantly better in GH-treated vs. untreated girls with TS, suggesting that beneficial effects upon body composition and regional fat deposition outweigh transient insulin antagonism associated with GH administration.

Disproportional geometry of the proximal femur in patients with Turner syndrome: a cross-sectional study

OBJECTIVE

Patients with Turner syndrome (TS) have altered growth and increased risk of osteoporosis due to oestrogen deficiency and possibly a host of other factors. Thus, TS patients have a 4.9-fold increased risk of femoral neck fractures. Most patients are treated with oestrogen during puberty and adolescence to facilitate pubertal development and prevent secondary osteoporosis. The geometry of the hip is a predictor for hip fractures independent of bone mineral density (BMD). The purpose of the present study was to investigate the variation of the geometry of the hip in patients with TS in comparison with healthy controls.

PATIENTS

The study population comprised 58 patients with TS (aged 22-67 years) and 60 age-matched healthy women (aged 21-65 years).

MEASUREMENTS

Hip axis length (HAL), neck width (NW), neck shaft angle (NSA), and femoral head-radius (HR) on dual-energy X-ray absorptiometry (DXA) screen images. These parameters related to age of oestrogen supplementation, menarche, and duration of oestrogen exposure.

RESULTS

Height was 146.6 +/- 6.9 cm and 167.1 +/- 6.2 cm (P < 0.1) and weight 57.4 +/- 13.9 kg and 62.3 +/- 8.3 kg (P < 0.001) in patients and controls, respectively. After adjustment for differences in height, HAL was not significantly different (9.4 +/- 0.5 vs. 9.5 +/- 0.5 cm; NS) in TS compared with controls while NW was significantly increased (3.5 +/- 0.4 cm vs. 3.3 +/- 0.2 cm, P < 0.001), NSA was similar (129 +/- 4 degrees vs. 130 +/- 4 degrees , NS), and HR was significantly decreased (4.1 +/- 0.4 vs. 4.5 +/- 0.3 cm, P < 0.001). The duration of oestrogen exposure was significantly shorter among TS, but did not correlate significantly with the geometrical parameters in either TS or controls.

CONCLUSION

Our data demonstrates that hip geometry is disproportionate in TS compared with normal controls. The altered hip geometry, however, cannot explain the increased risk of hip fracture in TS.

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.

Normal DXA bone mineral density but frail cortical bone in Turner's syndrome

CONTEXT

Patients with Turner's syndrome have normal bone mineral density by dual energy X-ray absorptiometry (DXA), but a predisposition for fractures. Quantitative ultrasonography (QUS) measures cortical bone strength.

OBJECTIVE

To compare QUS with DXA in patients with Turner's syndrome.

PATIENTS AND METHODS

Twenty-seven Turner's syndrome patients, aged 21.1 +/- 6.3 years (mean +/- SD), were evaluated by DXA, measuring two-dimensional bone mineral density (BMD), and QUS, measuring speed of sound (SOS) of the radius and tibia. The results were compared to sex- and age-matched (Ctr A, n = 53) and height-matched (Ctr B, n = 34) control groups.

RESULTS

Fracture incidence per 1000 women years was 4.76 in Ctr A, 5 in Ctr B and 7.69 in Turner's patients. In Turner's syndrome patients, QUS results were significantly lower than in controls, whereas DXA Z-scores were not different from reference values. Correlation between tibia and radius SOS and height and age in controls (P < 0.0001) was not evident in Turner's syndrome. Oestrogen or growth hormone therapy had no effect on either QUS or DXA parameters.

CONCLUSIONS

Bone fragility in Turner's syndrome is reflected by low SOS but not by DXA BMD. Low QUS, which assesses the cortical bone only, supports a defect in cortical bone in Turner's syndrome. Lack of SOS correlation with age, height and hormonal therapy in Turner's syndrome suggests a primary bone defect, rather than enhanced resorption of endocrine origin.

Chromosomal mosaicism mitigates stigmata and cardiovascular risk factors in Turner syndrome

OBJECTIVE

To study genotype-phenotype correlations in Turner syndrome (TS) regarding body composition, cardiovascular risk factors, stigmata and age at diagnosis vs. degree of mosaicism estimated as the percentage of 45,X and 46,XX cells.

METHODS

One hundred and twenty-six TS women, mean age 31 years, were examined by three specialists, who reported stigmata independent of each other. Dual energy X-ray absorptiometry (DXA) was used to measure bone mineral density (BMD). The karyotype was blinded. Fluorescence in situ hybridization (FISH) was performed on buccal cells. A random population sample served as controls.

RESULTS

Forty-four per cent exhibited a 45,X karyotype and 56% a second-cell line, while 27% of all had a 45,X/46,XX mosaicism. Five 45,X cases with a conventional karyotype were 45,X/46,XX mosaic according to FISH. At diagnosis, 45,X cases were younger (P < 0.05) and had more stigmata per person (P < 0.01) than the mosaics. TS with marker chromosome X or Y, iso or ring, did not differ from 45,X in this aspect. The mosaics had higher BMD and SHBG and lower total cholesterol and FSH than TS with 45,X and did not differ compared with controls in terms of body mass index (BMI), waist/hip ratio, BMD, blood pressure, cholesterol, triglycerides, SHBG, diabetes or osteoporosis. The number of stigmata correlated positively to BMI, waist/hip ratio, cholesterol and %45,X and inversely to height and %46,XX according to FISH.

CONCLUSIONS

Mosaicism seems to mitigate the TS phenotype and the cardiovascular risk factor profile. Mosaics were diagnosed 8 years later than 45,X cases. This emphasizes the necessity for a stricter genotype categorization not only in the clinic but also in research on TS than previously adopted.

Growth hormone treatment of non-growth hormone-deficient growth disorders

Although a large body of data on efficacy and safety of growth hormone (GH) treatment for various non-growth hormone-deficient (GHD) growth disorders has accumulated from a combination of clinical trial and postmarketing sources in the last 20 years or more, there remain limitations. Clinical trial data have the advantage of direct comparison of well-matched, randomized patient groups receiving treatment (or not) under comparable conditions and, as such, provide the highest quality evidence of efficacy. Clinical trials, however, are typically too small for any statistically valid assessment for safety, which is more comprehensively addressed using postmarketing data. Consequently, while the efficacy of GH treatment in children with non-GHD growth disorders has been solidly established and, based on the combination of the rigor of the clinical trial data and numerical power of the postmarketing data, no major concerns exist regarding safety, additional long-term data are required.

Clinical practice in Turner syndrome

Turner syndrome (TS) is a common genetic disorder, resulting from the partial or complete absence of one sex chromosome, and occurring in approximately 50 per 100,000 liveborn girls. TS is associated with reduced adult height and with gonadal dysgenesis, leading to insufficient circulating levels of female sex steroids and to infertility. Morbidity and mortality are increased in TS but average intellectual performance is within the normal range. A number of recent studies have allowed new insights to be gained with respect to epidemiology, genetics, cardiology, endocrinology and metabolism. Elucidation of the effects of short stature homeobox protein deficiency has explained some of the phenotypic characteristics in TS, principally short stature. Treatment with growth hormone during childhood and adolescence allows a considerable gain in adult height, although the consequences of this treatment in the very long term are not clear. Puberty must be induced in most cases, and female sex hormone replacement therapy (HRT) is given during adult years. The optimal dose of HRT has not been established and, likewise, the benefits and drawbacks of HRT have not been thoroughly evaluated. The risks of type 2 diabetes, type 1 diabetes, hypothyroidism, osteoporosis, congenital heart disease, hypertension, ischemic heart disease, aortic dilatation and dissection, inflammatory bowel disease and celiac disease are clearly elevated, and proper care during adulthood is important. Currently no firm guidelines for diagnosis exist. In conclusion, TS is a condition associated with a number of diseases and conditions that are reviewed in the present paper. Individuals with TS need life-long medical attention.

Nocturnal hypertension and impaired sympathovagal tone in Turner syndrome

OBJECTIVE

Increased blood pressure (BP), night: day BP ratio, and heart rate is seen in Turner syndrome (TS), and an increased risk of ischaemic heart disease and type 2 diabetes, as well as aortic dilatation and dissection. We hypothesized that altered heart rate variability is present in TS in comparison with controls, and can be influenced by hormonal replacement therapy (HRT).

MATERIAL AND METHODS

We examined the impact of HRT on sympathovagal control of heart rate variability. Patients (n = 8, aged 29.5 +/- 5.3 years; no treatment or HRT) and controls (n = 8, aged 28.5 +/- 4.2 years; no treatment) were examined by short-term spectral analysis (supine-standing), bedside neuropathy tests, and 24-h ambulatory BP. N-terminal pro-brain natriuretic peptide (BNP), renin, aldosterone and urinary albumin excretion was determined. The interaction between position and status (TS or control) was examined for data from spectral analysis.

RESULTS

Low-frequency (LF) power, coefficient of component variation of LF (both measures of sympathetic and vagal activity), and the LF: high-frequency (HF) power ratio (a measure of sympathovagal balance) were diminished in TS compared with controls, especially during standing. Systolic and diastolic night ambulatory BP (both P = 0.03), and systolic and diastolic night: day ratio (P = 0.01; P = 0.004) was increased in TS. During HRT diastolic day (P = 0.05) and 24-h diastolic ambulatory BP (P = 0.08) decreased. N-terminal pro-BNP was elevated in TS.

CONCLUSION

Decreased sympathovagal balance or tone and nocturnal hypertension is present in TS, and N-terminal pro-BNP is elevated. HRT did not modulate the sympathovagal tone, but decreased BP. These changes may be linked to the increased cardiovascular risk and possibly the increased risk of aortic dilatation in TS.

Turner syndrome in adulthood

Turner syndrome is a common genetic disorder associated with abnormalities of the X chromosome and occurs in about 50 per 100,000 liveborn girls. It is associated with reduced adult height, gonadal dysgenesis and thus insufficient circulating levels of female sex steroids and infertility. Morbidity and mortality are increased throughout the lifespan. The average intellectual performance is within the normal range. A number of recent clinical studies have given new insight particularly into the adult phase of Turner syndrome. Treatment with growth hormone during childhood and adolescence enables a considerable gain in adult height. In most cases puberty has to be induced and female sex hormone replacement therapy is given during adulthood. Type 2 diabetes is often seen, and hypertension and associated cardiovascular disorders are frequent. The proper treatments of these disorders have not been firmly established. Since the risk of cardiovascular and endocrinological disease is clearly elevated, proper care during adulthood is crucial. Cognition and social functioning are altered in Turner syndrome.

Microdeletion in the SHOX 3' region associated with skeletal phenotypes of Langer mesomelic dysplasia in a 45,X/46,X,r(X) infant and Leri-Weill dyschondrosteosis in her 46,XX mother: implication for the SHOX enhancer

It is known that SHOX nullizygosity results in Langer mesomelic dysplasia (LMD) and SHOX haploinsufficiency leads to Leri-Weill dyschondrosteosis (LWDC). Here, we report on a microdeletion in the SHOX 3' region identified in a Japanese infant with LMD-compatible skeletal features and a 45,X[191]/46,X,r(X)(p22.3q24)[9] karyotype and in her mother with LWDC-compatible skeletal features and a normal 46,XX karyotype. Physical and auxological examinations revealed mesomelic appearance, ulnarly deviated hands, and borderline micrognathia in the infant, and relatively short forearms and lower legs in the mother. Radiological studies indicated mesomelia, markedly curved radii, hypoplastic ulnas and fibulas, and metaphyseal splaying in the infant, and borderline to mild curvature of the radii, decreased carpal angles, and high-normal triangularization index in the mother. Cytogenetic and molecular studies showed that the ring X chromosome of the infant was missing SHOX and of paternal origin, whereas the cytogenetically normal X chromosomes of the infant and one of the two X chromosomes of the mother, though they retained SHOX with normal coding sequences, had a microdeletion in the SHOX 3' region. The microdeletion started from a position approximately 200 kb from SHOX coding sequences, and spanned 240-350 kb in physical length involving DXYS233. The results, in conjunction with those reported by Flanagan et al. [2002], suggest that a cis-acting enhancer exists in the SHOX 3' region around DXYS233.

Proporções corporais em um grupo de pacientes brasileiras com Síndrome de Turner

OBJETIVO: Trata-se do primeiro estudo brasileiro com o objetivo de avaliar as proporções corporais de pacientes com síndrome de Turner (ST) não tratadas com hormônio de crescimento. MÉTODOS: Estudo transversal de 50 pacientes com ST (5 a 43 anos), avaliando-se idade, cariótipo, desenvolvimento puberal e medidas de estatura em pé e sentada, envergadura, peso, IMC, perímetro cefálico, mão e pé, perna, relação entre cintura e quadril, diâmetros biacromial e bi-ilíaco. Transformação dos dados em escore z de desvio-padrão. Realizada análise descritiva e aplicados o teste de Mann-Whitney e a análise de variância. RESULTADOS: Não foram observadas diferenças das variáveis em relação aos cariótipos: 22 eram impúberes e 28 púberes, e todas as variáveis em valores absolutos foram significativamente maiores na puberdade. Não foram observadas diferenças em relação aos escores z das variáveis analisadas em relação à puberdade. Todas as variáveis apresentaram escores z médios acima de -2, com exceção da estatura em pé e envergadura nas impúberes e também da estatura sentada e da mão nas púberes. O mesmo foi observado quando se analisou as 15 pacientes com idade > 20 anos, sendo apenas o peso, o IMC e os diâmetros biacromial e bi-ilíaco significativamente menores que os dados dinamarqueses de Gravholt e Naeera de 1997. CONCLUSÃO: O comprometimento de crescimento na ST ocorre fundamentalmente no eixo longitudinal, e os resultados observados neste estudo são comparáveis aos dinamarqueses.

Effect of growth hormone and 17beta-oestradiol treatment on metabolism and body composition in girls with Turner syndrome

OBJECTIVE

Girls with Turner syndrome (TS) receive GH treatment during childhood, and in adolescence this treatment may be combined with oestradiol. We have studied the effects of this combined treatment on metabolism and body composition.

MATERIAL AND METHODS

We performed a double-blind, placebo-controlled, randomized, crossover study. All girls with TS (n = 8, 16 +/- 2 years) were treated with placebo + placebo, GH + placebo or GH + 17beta-oestradiol for 2 months, and were studied at the end of each period. Controls (n = 10, 14 +/- 2 years) were studied once without treatment. Twenty-four-hour sampling of oestradiol, growth factors, insulin, glucose, lipolytic and gluconeogenic precursors was performed, followed by an oral glucose tolerance test (OGTT) and assessment of body composition and mineral content.

RESULTS

GH induced insulin resistance, which was not aggravated further by concomitant oestradiol treatment. The 24-h integrated serum 17beta-oestradiol was reduced compared to controls (0.58 +/- 0.32 vs. 2.81 +/- 2.78 nmol/l/24 h, P = 0.032), but increased during GH + oestrogen (E2) treatment without reaching control levels, while GH + placebo caused a further reduction (anova, P = 0.008). Total fat mass was increased in girls with TS compared with controls (P = 0.009), while lean body mass (P = 0.02) and bone mineral content (P = 0.04) was decreased, with specific regional characteristics in body composition.

CONCLUSION

GH treatment induces insulin resistance and changes in body composition in TS, which is not further compromised by concomitant oestradiol treatment. Body composition is changed in TS, with specific regional changes, in comparison with controls. Integrated 24-h oestradiol is low in TS, and is only partially restored during treatment with standard doses of 17beta-oestradiol.

[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.

Endocrine control of body composition in infancy, childhood, and puberty

Body composition exhibits marked variations across the early human lifetime. The precise physiological mechanisms that drive such developmental adaptations are difficult to establish. This clinical challenge reflects an array of potentially confounding factors, such as marked intersubject differences in tissue compartments; the incremental nature of longitudinal intrasubject variations in body composition; technical limitations in quantitating the unobserved mass of mineral, fat, water, and muscle ad seriatim; and the multifold contributions of genetic, dietary, environmental, hormonal, nutritional, and behavioral signals to physical and sexual maturation. From an endocrine perspective (reviewed here), gonadal sex steroids and GH/IGF-I constitute prime determinants of evolving body composition. The present critical review examines hormonal regulation of body composition in infancy, childhood, and puberty.

Impaired insulin secretion in the Turner metabolic syndrome

An increased prevalence of impaired glucose homeostasis (IGH) and diabetes mellitus is reported in monosomy X, or Turner syndrome (TS). To determine whether IGH is an intrinsic feature of this syndrome, independent of obesity or hypogonadism, we compared results of a standard oral glucose challenge in age- and body mass index-matched women with TS and with karyotypically normal premature ovarian failure (POF). Fasting glucose levels were normal in both groups, but glucose values after oral glucose challenge were higher in TS [2-h glucose, 135 +/- 36 mg/dl (7.5 +/- 2.0 mmol/liter) in TS and 97 +/- 18 mg/dl (5.4 +/- 1.0 mmol/liter) in POF; P < 0.0001]. Glucose-stimulated insulin secretion was lower in TS; e.g. the initial insulin response (DeltaI/DeltaG(30)) was decreased by 60% compared with POF (P < 0.0001). We also compared responses to a standard iv glucose tolerance test in women with TS and in age- and body mass index-matched normal women and found that the insulin area under the curve was 50% lower in women with TS (P = 0.003). Insulin sensitivity measured by the quantitative insulin sensitivity check index was higher in women with TS compared with both control groups. Thus, IGH is not secondary to obesity or hypogonadism in TS, but it is a distinct entity characterized by decreased insulin secretion, suggesting that haploinsufficiency for X-chromosome gene(s) impairs beta-cell function and predisposes to diabetes mellitus in TS.

Importance of estrogen on bone health in Turner syndrome: a cross-sectional and longitudinal study using dual-energy X-ray absorptiometry

Osteoporosis and fractures are features in adults with Turner syndrome (TS). Using dual-energy x-ray absorptiometry, correcting bone mineral content (BMC) for height and lean mass (LTM) avoids misclassification of short children as osteopenic. Total body (TB), lumbar spine (LS), and femoral neck (FN) dual-energy x-ray absorptiometry scans were performed on 83 patients with TS (aged 4-24 yr). A prepubertal subgroup (n = 17) receiving GH was followed for 24 months. Age z-scores for height, TB BMC, LTM, the BMC/LTM ratio, and LS volumetric bone mineral density (vBMD) decreased significantly (P < 0.001) with age in prepubertal subjects (n = 51) but were constant in the combined pubertal and postmenarchal group (n = 32). Osteopenia was found in 14.5% (TB), 15.8% (LS), and 28.4% (FN) of patients. In the longitudinal subgroup, TB BMC z-scores decreased by -0.28 (0.31) in subjects remaining prepubertal (n = 11) but increased by 0.71 (0.56) in subjects entering puberty (n = 6; P = 0.007). The z-scores for height and LTM increased in both groups. Our results show a height-independent prepubertal decrease in bone mass accrual, which ceased with puberty. Optimizing bone mass in TS may require earlier induction of puberty than currently recommended. However, reduced FN volumetric bone mineral density and a dissociation of bone and muscle measures were age independent, suggesting an additional intrinsic bone defect.

Short-term growth hormone treatment in girls with Turner syndrome decreases fat mass and insulin sensitivity: a randomized, double-blind, placebo-controlled, crossover study

BACKGROUND

Most girls with Turner syndrome (TS) receive growth hormone (GH) treatment during childhood and adolescence, but controlled data on the effects on body composition and glucose metabolism are lacking.

OBJECTIVE

To study the effects of GH treatment on insulin sensitivity, glucose metabolism, bone turnover, and body composition.

METHODS

A randomized, placebo-controlled, crossover study was conducted with girls with TS. All girls with TS were treated with GH 0.1 IU/kg/d subcutaneously at bedtime or with placebo for 2 months and studied at the end of each period. Control subjects were studied once without treatment. Twelve girls with TS, aged 9.5 to 14.8 years (median: 12.9 years) and 16 age-matched control subjects (10.3-16.0 years; median: 12.1 years) were studied. Twenty-four-hour sampling of blood was performed; GH, insulin-like growth factor I (IGF-I), IGF binding proteins (IGFBPs), insulin, glucose, and lipolytic and gluconeogenic precursors were assayed, followed by an oral glucose tolerance test. Body composition was evaluated by dual-energy x-ray absorptiometry scanning and body mass index (BMI). Fasting bone markers were measured.

RESULTS

Height was reduced in TS as compared with control subjects. In the placebo situation, 24-hour integrated GH as well as IGF-I was significantly reduced in girls with TS compared with control subjects. Controlling for differences in lean body mass (LBM; or fat mass [FM]) and sexual development did not explain the difference in 24-hour integrated GH. Differences in sexual development, BMI, FM, insulin sensitivity, and IGFBP-3 could explain the difference in IGF-I between TS and control subjects. Carbohydrate metabolism in TS was comparable with control subjects. GH treatment induced insulin resistance, with increments in fasting glucose and insulin, as well as 24-hour insulin. Circulating levels of lipid and gluconeogenic substrates were comparable in TS and control subjects and unchanged in response to treatment. Bone markers increased in response to GH. Total FM was increased in girls with TS, accounted for by an increased FM in the arms and trunk, whereas LBM was decreased. Especially LBM in the legs was decreased. Overall, bone mineral content was diminished. Treatment with GH reduced FM in TS, especially in the arms and legs, and likewise increased total LBM, primarily in the trunk.

CONCLUSION

This study documented evidence of impaired GH secretion and action, disproportionate body composition, but a normal carbohydrate metabolism in girls with TS. Short-term GH administration was associated with favorable changes in body composition but also with relative impairment of glucose tolerance and insulin sensitivity. We recommend that glucose metabolism be monitored carefully during long-term GH treatment in these patients.

Marked disproportionality in bone size and mineral, and distinct abnormalities in bone markers and calcitropic hormones in adult turner syndrome: a cross-sectional study

Most women with Turner syndrome (TS) have no gonadal activity and thus lack estrogen. Bone mineral density (BMD) is often reduced, leading to an increased risk of osteoporosis and fractures. However, growth retardation with reduced final height and other endocrine disturbances may compromise interpretation of skeletal measurements. The aim of the present study was to explore skeletal findings, bone metabolism, and calcium homeostasis in TS. Sixty women with TS (age, 37 +/- 9 yr) and 181 normal age-matched female controls were studied. Bone area (A; square centimeters), bone mineral content (BMC; grams), area-adjusted BMD (aBMD; grams/square centimeter), and volumetric BMD (vBMD; grams/cubic centimeter) were measured at lumbar spine, femoral neck, and forearm using dual energy x-ray absorptiometry. Twenty-eight percent had osteopenia, and 23% had osteoporosis, according to World Health Organization criteria. At the lumbar spine, A, BMC, aBMD, and vBMD were reduced by 18, 27, 11, and 6%, respectively; at the femoral neck, A, BMC, and aBMD were reduced by 2, 10, and 8%, respectively, whereas the 9% reduction in vBMD was insignificant (P = 0.07); and in the forearm, A, BMC, and aBMD were reduced by 53, 55, and 9%, respectively. Bone markers indicated an enhanced bone resorption (21 and 23% increase in C-terminal and N-terminal cross-linking telopeptides of type I collagen/creatinine, respectively) with unchanged (osteocalcin, procollagen I N-terminal propeptide) or reduced (54% reduction in bone alkaline phosphatase) bone formation. Plasma levels of calcium and 25-hydroxyvitamin D (26%) were reduced, and PTH levels increased (74%) in TS. IGF-I (30%), IGF binding protein 3 (18%), testosterone (50%), and SHBG (40%) were reduced in TS. In summary, A, BMC, and aBMD were found to be universally reduced in TS, whereas vBMD was slightly reduced in the spine. Increased resorption of bone was present, with normal or blunted bone formation, suggesting uncoupling or imbalance in bone remodeling. Skeletal changes may be induced by chromosome abnormalities or by secondary endocrine or metabolic changes related to a relative estrogen deficiency, testosterone deficiency, reduced IGF-I, low vitamin D status, and secondary hyperparathyroidism.

Kyphosis in a Turner syndrome population

OBJECTIVE

The purpose of this study was to determine the prevalence of kyphosis in a Turner syndrome (TS) population.

METHODS

Standing lateral thoracic spine and standing anterior-posterior (A-P) scoliosis radiographs were obtained on all girls with TS between the ages of 5 and 18 years seen in a TS clinic between July 2000 and March 2001. Medical histories were reviewed, and a pediatric orthopedic surgeon evaluated the radiographs of each patient (N = 25). Excessive kyphosis was defined as an A-P curvature >40 degrees, vertebral wedging as any A-P deformity >5 degrees at an individual vertebral body, and scoliosis as a lateral curvature >10 degrees.

RESULTS

Fifteen (60%) of 25 patients were found to have abnormal radiographic findings: 10 (40%) of 25 with excessive kyphosis, 10 (40%) of 25 with vertebral wedging, and 5 (20%) of 25 with scoliosis. Forty-eight percent of the girls had both excessive kyphosis and/or vertebral body wedging. Two girls had kyphosis > or =55 degrees, and 5 had scoliosis > or =25 degrees. Girls with excessive kyphosis and/or vertebral body wedging were older (13.6 +/- 3.9 years vs 10.6 +/- 2.8 years).

CONCLUSIONS

The prevalence of excessive kyphosis and vertebral body wedging seems to be increased in girls with TS and corresponds with advancing age. Routine radiologic surveillance may facilitate detection of developing deformities so that treatment with a brace can be considered to prevent or slow the process.

Turner's syndrome: a paediatric perspective

In childhood the symptoms with the greatest impact on girls with Turner's syndrome are: (1) congenital cardiac abnormalities (which can be corrected by surgical intervention); (2) short stature (mean adult height between 142 and 147 cm); and (3) ovarian failure (absent spontaneous puberty). Recent studies have shown that growth hormone (GH) treatment in young girls (8 years of age or younger) with Turner's syndrome results in normalization of adult height in most of the girls when using the 'standard' GH dose of about 4 IU/m(2) per day ( approximately 0.045 mg/kg per day). Higher GH doses (6 or 8 IU/m(2) per day) or the use of oxandrolone may be more effective, but their efficacy on adult height and safety in the very long term still have to be proven. If GH treatment is started early, low-dose oestrogens for induction of puberty can be given at 12 years of age without interfering with the capability of the GH treatment to normalize adult height. GH does not seem to have negative side effects on body proportions, cardiac dimensions, blood pressure, carbohydrate metabolism or bone mineral density.

Short bi-iliac distance in prenatal Ullrich-Turner syndrome

The purpose of the present study is to evaluate the bi-iliac distance and the caudo-cranial position of the iliac bones in Ullrich-Turner syndrome (UTS) fetuses compared to recently published standards for normal fetuses. Whole-body radiographs in antero-posterior projections of 24 UTS fetuses (crown-rump lengths, 106-220 mm) were included in the study. From each radiograph, two horizontal (outer and inner bi-iliac distances) and two vertical (caudo-cranial) positions compared to the vertebral column were measured to estimate the position of the iliac bones. The present investigation revealed that both the outer and inner bi-iliac distances were significantly shorter in UTS fetuses than in normal fetuses. We also found that for the inner bi-iliac distance, the growth rate in UTS fetuses was significantly lower than in normal fetuses. This finding suggests not only a lesser growth but also a different growth pattern compared to normal fetuses. Regarding the caudo-cranial position of the iliac bones compared to the lower vertebral column, there was no significant difference for the lower caudo-cranial position, but the upper caudo-cranial position was significantly lower in UTS fetuses than in normal fetuses. The bi-iliac distance and the iliac bone position have not previously been described in Ullrich-Turner syndrome fetuses.

Turner syndrome and the heart: cardiovascular complications and treatment strategies

Turner syndrome is a condition usually associated with reduced final 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. With respect to cardiac function, congenital malformations of the heart and the great vessels, hypertension and ischemic heart disease, and increased risk of aortic dissection are all conditions that the pediatrician or the physician caring for females with Turner syndrome should keep in mind. Many girls and adolescents with Turner syndrome receive growth hormone (GH) treatment, which has so far been an effective and well-tolerated therapy. Nevertheless, because of the experience from acromegaly, the physician should monitor blood pressure and perform echocardiography, together with clinical examinations by a cardiologist at regular intervals. During adulthood most women with Turner syndrome are faced with premature menopause and the need for female hormone replacement therapy (HRT). During clinical evaluation of girls and women with Turner syndrome, these conditions and complications should be kept under surveillance. Here the cardiovascular complications of Turner syndrome are reviewed. The risk of congenital heart defects such as bicuspid aortic valves, aortic coarctation, other valve abnormalities, and septal defect is increased. Likewise, the risk of aortic dissection at a young age is increased, as is the risk of hypertension, ischemic heart disease, and stroke. GH therapy does not seem to adversely affect the heart, although longer-term follow-up studies are needed. In short-term studies, HRT lowers blood pressure, while any effect on the risk of ischemic heart disease has not been evaluated. Treatment with GH and HRT are discussed in relation to the heart and great vessels. Presently, the pathophysiology of the congenital cardiovascular malformation in Turner syndrome is unexplained, although different theories exist. Recommendations for clinical practice are given, including life-long surveillance of cardiac function, aortic diameter and blood pressure.

Aspects of the treatment of Turner syndrome

Several issues have to be considered when taking care of girls and women with Turner syndrome. During childhood, short stature is the primary concern and treatment with growth hormone (GH) is now widely used, often in conjunction with the androgen, oxandrolone. Recent studies indicate that doses used previously in the treatment of short stature have been too small. Induction of puberty should be performed at an appropriate age with reference to the peers of the patient. In adulthood, female sex hormone substitution should be offered to possibly prevent the increased morbidity seen in Turner syndrome, which consists of increased risk of fractures and osteoporosis, a clustering of diseases like ischaemic heart disease, hypertension, stroke and Type 2 diabetes, the latter entities being involved in the insulin resistance syndrome. Furthermore, hypothyreosis are often seen and the risk of Type 1 diabetes may also be increased. Congenital malformations of the heart are frequently seen in Turner syndrome, possibly increasing the risk of dissecting aorta aneurism. Liver enzymes are often elevated in Turner syndrome and there may be an increased risk of cirrhosis of the liver. Mortality does seem to be increased in Turner syndrome and women with the 'pure' 45,X karyotype do seem to be most severely affected. In the clinical practice of Turner syndrome, a careful monitoring of glucose and bone metabolism, weight, thyroid function and blood pressure should be performed. A cardiovascular risk profile should be determined and the patient informed concerning risks and benefits from sex hormone replacement therapy. Based on the available literature, sex hormone replacement therapy is highly recommended, although at present there are no longitudinal data documenting the long-term positive effect of sex steroid substitution. However, hypogonadism is expected to explain at least part of the decreased lifespan found in Turner syndrome. Since general physicians encounter Turner patients infrequently, it is recommended that the care and treatment of Turner syndrome is centralised.

Muscle fiber composition and capillary density in Turner syndrome: evidence of increased muscle fiber size related to insulin resistance

OBJECTIVE

To assess muscle fiber composition and capillary density in Turner syndrome, a condition linked with insulin resistance and increased frequency of type 2 diabetes, and link these findings with insulin sensitivity and physical fitness.

RESEARCH DESIGN AND METHODS

A total of 10 patients with Turner syndrome who were off hormone replacement therapy (aged 32.7 +/- 8.9 years) and a control group of 14 normal women (aged 35.6 +/- 9.3 years) were studied. None of the participants had diabetes or any family history of type 2 diabetes. An oral glucose tolerance test was performed, and insulin sensitivity was assessed by homeostasis model assessment (HOMA) and a composite whole-body insulin sensitivity index (ISI(comp)). Physical fitness was assessed, and a muscle biopsy was obtained.

RESULTS

Women with Turner syndrome were insulin resistant, as seen by a lower ISI(comp) (P = 0.003) and increased glucose (P < 0.0005) and insulin (P = 0.01) levels at 120 min. Impaired glucose tolerance was present in most Turner syndrome patients (6 of 10), but not in the control subjects. Women with Turner syndrome had an increased size of type IIa fibers (P = 0.01), whereas the size of their type I and IIa fibers were comparable with the control group. The groups did not differ in percentage of type I, Iia, or IIx fibers, and there was no difference in the capillary density. Significant correlations were found among ISI(comp), the HOMA index (R(HOMA)), and the mean area of type IIa fibers (ISI(comp): r = -0.632, P = 0.002; R(HOMA): r = 0.570, P = 0.006). Furthermore, capillaries/type IIa fibers correlated significantly with ISI(comp) (r = -0.618, P = 0.01). There were no significant correlations between VO(2max) and muscle fiber composition.

CONCLUSIONS

Healthy women with Turner syndrome are characterized by impaired glucose tolerance, insulin resistance, low physical capacity, and enlarged type IIa muscle fibers, indicating diminished oxygen and substrate supply for metabolic processes. These findings could be indicative of a prediabetic state.