Physiological and catecholamine response to sympathetic stimulation in turner syndrome

Malignant hypertension in a patient with Turner syndrome: A case report

RATIONALE

Turner syndrome is characterized by complete or partial loss of the second sex chromosome. In patients with Turner syndrome, hypertension is well described. However, the literature regarding malignant hypertension is scarce. Therefore, an accurate and timely diagnosis and treatment are important.

PATIENT CONCERNS

A 13-year-old female with Turner syndrome presented to the emergency department with malignant hypertension, headache, spraying vomiting, convulsion, and loss of consciousness. Considering her medical history, symptoms, and auxiliary examination, secondary hypertension (primary reninism) was suspected, but without any occupying or hyperplasia in renal and adrenal.

DIAGNOSIS

A type of secondary hypertension, primary reninism.

INTERVENTIONS

The patient was immediately transferred to the pediatric intensive care unit. Subsequently, she was given nifedipine 0.35 mg/kg and captopril 0.35mg/kg to reduce blood pressure (BP), mannitol and furosemide to reduce cranial pressure, and phenobarbital and midazolam to terminate restlessness successively. Three hours later, the BP was consistently higher than 170/120 mm Hg, sodium nitroprusside was pumped intravenously, then, giving oral drug transition. Finally, she was given Valsartan-Amlodipine Tablets (I) (80 mg valsartan and 5 mg amlodipine per day) and bisoprolol (2.5 mg per day).

OUTCOMES

For 2.5 years of follow-up, the BP reduced to 110-130/60-85 mm Hg, heart rate ranged between 65 and 80 bpm, and she could go to school without any headache, convulsion, and syncope.

LESSONS

The clinical phenotype of Turner syndrome is complex and varied, affecting multiple systems and organs. Turner syndrome with malignant hypertension is rare, so we should systematically evaluate secondary hypertension, target-organ damage, and accompanied by standard management when Turner syndrome presents with hypertension.

The prevalence of hypertension in paediatric Turner syndrome: a systematic review and meta-analysis

Cardiovascular related deaths account for over 40% of the excess mortality in Turner syndrome (TS). Hypertension, a modifiable risk factor for both aortic dilatation and dissection, is more commonly encountered in TS during childhood and adolescence. Treatment of hypertension is currently recommended beyond the age of 16 years in TS to help reduce the risk of aortic dissection. This study aims to determine the prevalence of hypertension in paediatric patients with TS and explore the associated methodologies of blood pressure evaluation reported in these studies. Three online databases were searched (Medline, Embase and Web of Science) for literature which reported a prevalence, or allowed calculation of prevalence, of hypertension in patients with TS who were 18 years of age or younger. Seventeen studies which met the primary eligibility criteria, with a total of 1948 patients, were included. The estimated pooled prevalence of hypertension in children and adolescents with TS was 16% (95% CI: 8.9-24.6%). There was significant heterogeneity detected between the studies. The prevalence of hypertension in those studies which assessed 24-h Ambulatory Blood Pressure Monitoring (ABPM) was 21.1% (95% CI: 15.2-27.6%) compared those which used another method of blood pressure measurement which was 13.5% (95% CI: 5.2-24.4%). Given the impact of hypertension with long-term health outcomes and the reversibility of these same outcomes by addressing abnormal blood pressure, prompt and early diagnosis of hypertension in young girls with TS should be prioritised. We recommend the use of 24-h ABPM in screening for hypertension in the paediatric 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.

Cardiovascular considerations in management of patients with Turner syndrome

Turner syndrome (TS) is a chromosomal disorder that affects 25-50 per 100,000 live born females. Patients with TS face a heavy burden of cardiovascular disease (congenital and acquired) with an increased risk of mortality and morbidity compared to the general population. Cardiovascular diseases are a major cause of death in females with TS. Approximately 50% of TS patients have a congenital heart abnormality, with a high incidence of bicuspid aortic valve (BAV), coarctation of the aorta (CoA) and generalised arteriopathy. Frequently, females with TS have systemic hypertension, which is also a risk factor for progressive cardiac dysfunction and aortopathy. This paper aims to provide an overview of the cardiovascular assessment, management and follow up strategies in this high-risk population of TS patients.

Cardiovascular Complications in Patients with Turner's Syndrome

Turner's or Turner syndrome (TS) is the most prevalent chromosomal abnormality in live female births. Patients with TS are predisposed to an increased risk of cardiovascular diseases (CVD), mainly due to the frequently observed congenital structural cardiovascular defects, such as valvular and aortic abnormalities (coarctation, dilatation, and dissection). The increased prevalence of cardiometabolic risk factors, such as arterial hypertension, insulin resistance, diabetes mellitus, dyslipidaemia, central obesity, and increased carotid intima-media thickness, also contribute to increased morbidity and mortality in TS patients. Menopausal hormone therapy (MHT) is the treatment of choice, combined with growth hormone (GH). Although MHT may, in general, ameliorate CVD risk factors, its effect on CVD mortality in TS has not yet been established. The exact effect of GH on these parameters has not been clarified. Specific considerations should be provided in TS cases during pregnancy, due to the higher risk of CVD complications, such as aortic dissection. Optimal cardiovascular monitoring, including physical examination, electrocardiogram, CVD risk factor assessment, and transthoracic echocardiography, is recommended. Moreover, the cardiac magnetic resonance from the age of 12 years is recommended due to the high risk of aortic aneurysm and other anatomical vascular complications.

A value-based healthcare approach: Health-related quality of life and psychosocial functioning in women with Turner syndrome

OBJECTIVE

As part of the value-based healthcare programme in our hospital, a set of patient-reported outcome measures was developed together with patients and implemented in the dedicated Turner Syndrome (TS) outpatient clinic. This study aims to investigate different aspects of health-related quality of life (HR-QoL) and psychosocial functioning in women with TS in order to establish new possible targets for therapy.

DESIGN/PARTICIPANTS

A comprehensive set of questionnaires (EQ-5D, PSS-10, CIS-20, Ferti-QoL, FSFI) was developed and used to capture different aspects of HR-QoL and psychosocial functioning in a large cohort of adult women with Turner syndrome. All consecutive women, ≥18 years, who visited the outpatient clinic of our tertiary centre were eligible for inclusion.

RESULTS

Of the eligible 201 women who were invited to participate, 177 women (age 34 ± 12 years, mean ± SD) completed at least one of the validated questionnaires (88%). Women with TS reported a lower health-related quality of life (EQ-5D: 0.857 vs 0.892, P = .003), perceived more stress (PSS-10:14.7 vs 13.3; P = .012) and experienced increased fatigue (CIS-20: P < .001) compared to the general Dutch population. A relationship between noncardiac comorbidities (eg diabetes, orthopaedic complaints) and HR-QoL was found (R = .508).

CONCLUSIONS

We showed that TS women suffer from impaired HR-QoL, more perceived stress and increased fatigue compared to healthy controls. A relationship between noncardiac comorbidities and HR-QoL was found. Especially perceived stress and increased fatigue can be considered targets for improvement of HR-QoL in TS women.

Assessment of left ventricular myocardial work in Turner syndrome patients: insights from the novel non-invasive pressure-strain loop analysis method

Background

Turner syndrome (TS), a relatively rare chromosomal disease, is associated with multiple cardiovascular risk factors that possibly lead to increased left ventricular afterload and functional impairment. The aim of this study was to investigate whether alterations in myocardial work and work efficiency can be found in TS patients through left ventricular pressure-strain loop analysis (PSL).

Methods

Thirty-eight patients with TS and 19 healthy, age-matched controls were recruited for this study. Global peak systolic strain (GLPS) and PSL of the left ventricle was assessed in study participants. TS patients whose history included coarctation of the aorta or prior cardiac surgery were excluded from GLPS and PSL analyses (n=5).

Results

Median age was 16.00 years in the TS group and 16.35 years in the control group (P=0.236). GLPS did not show significant differences between both groups (P=0.524). TS patients demonstrated, compared to controls, a significantly higher global myocardial work index (BSA) (mean ± SD: 1,497±505 vs. 1,214±245 mmHg*%/m²; P=0.027). Heart rate was significantly increased in TS patients, compared to controls (mean ± SD: 90.08±14.79 vs. 73.95±15.05 bpm; P<0.001), and correlated significantly with global myocardial work index [body surface area (BSA)] within the TS cohort (r=0.558, P=0.001).

Conclusions

TS patients showed signs of increased myocardial workload that were only detectable through the novel PSL analysis method and not through GLPS. Moreover, elevated resting heart rate was linked with increased myocardial workload in TS patients. Further studies will have to investigate whether TS patients may develop advanced left ventricular systolic dysfunction later in life.

Left ventricular remodelling among Turner syndrome patients: insights from non-invasive 3D echocardiography-derived pressure-volume loop analysis

BACKGROUND

Turner syndrome (TS) is a X-chromosomal disease affecting one in 2500-3000 female newborns. TS individuals are at high cardiovascular risk and more likely to be overweight or obese. The aim of this study was to assess left ventricular performance in TS patients through three-dimensional speckle tracking echocardiography (3DSTE) and non-invasive left ventricular pressure-volume loop (PVL) analysis. Moreover, this study focused on the impact of excess weight on the left ventricular efficiency in TS patients.

METHODS

Thirty-six TS patients and 19 healthy age-matched controls were included in this study. 3DSTE and non-invasive left ventricular PVL analysis were performed and left ventricular efficiency parameters were calculated.

RESULTS

TS patients had significantly lower values than controls in longitudinal strain (- 16.67 ± 3.23% vs. - 18.47 ± 1.87%; p = 0.029), but significantly higher values for arterial elastance (BSA) (3.31, 1.87-5.88 mmHg/mL vs. 2.99, 2.31-4.61 mmHg/mL; p = 0.011) and cardiac work (BSA) (292,070 ± 71,348 mmHg*mL*HR vs. 248,595 ± 70,510 mmHg*mL*HR; p = 0.036). Compared with normal weight patients, overweight and obese TS subjects demonstrated worse left ventricular efficiency (175.08 ± 17.73 mmHg vs. 157.24 ± 26.75 mmHg; p = 0.037). Even after excluding TS patients with cardiovascular morbidity, arterial elastance (BSA) was compared to healthy peers, significantly increased in TS patients.

CONCLUSIONS

3DSTE and non-invasive left ventricular PVL analysis might be useful tools to detect early cardiac changes in TS. Arterial elastance seems to be significantly increased in TS patients, independent of cardiovascular morbidity. Compared with normal weight TS patients, overweight/obese TS patients displayed lower left ventricular efficiency.

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.

Two-dimensional speckle tracking of the abdominal aorta: a novel approach to evaluate arterial stiffness in patients with Turner syndrome

Background

Turner syndrome (TS) is an X-chromosomal disease affecting one in 2,500-3,000 female newborns. Girls and women with TS show multiple cardiovascular risk factors that all have an impact on arteriosclerosis and thus arterial stiffness. An accurate and non-invasive screening of arterial stiffness is essential to improve the overall outcome in these patients.

Methods

Thirty-five TS patients and 19 healthy, age-matched controls were prospectively recruited for this study. Arterial stiffness was measured at the abdominal aorta in subxiphoid view using two-dimensional speckle tracking (2DST). Acquisition was performed at a frame rate of 60-90 fps. Mean peak circumferential strain (AAO-S, %) was measured offline for respective layers (inner layer = AAO-SENDO, %; middle layer = AAO-SMESO, %; outer layer = AAO-SEPI, %).

Results

Compared with the control group, patients with TS showed significantly lower peak circumferential strain values in each layer [AAO-SENDO (mean ± SD): 10.98%±4.73% vs. 15.32%±4.78%, P=0.002; AAO-SMESO (mean ± SD): 6.36%±2.22% vs. 9.18%±2.83%, P<0.001; AAO-SEPI (mean ± SD): 4.49%±1.76% vs. 6.31%±2.53%, P=0.003]. Abdominal aortic strain values correlated significantly with left ventricular diastolic function assessed by mitral early (E) and late (A) flow ratio (AAO-SENDO and E/A: r=0.475, P<0.001; AAO-SMESO and E/A: r=0.504, P<0.001; AAO-SEPI and E/A: r=0.393, P=0.003). Heart rate correlated significantly negative with 2DST assessed arterial distensibility (r=-0.366; P=0.007). Relative intra- and interobserver variability ranged between 8.67% and 21.03% for 2DST of the abdominal aorta.

Conclusions

2DST of the abdominal aorta might provide additional diagnostic value to detect possible functional vascular impairments in patients with TS. Left ventricular diastolic function is coupled with increased arterial stiffness in TS patients. The relatively high intra- and interobserver variability of 2DST of the abdominal aorta requires further improvement of the speckle tracking algorithm.

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.

Biochemical and Clinical Features of Insulinoma in a Patient with Turner Syndrome

Turner syndrome (TS), i.e., mosaic or nonmosaic states with only one normal X chromosome in females, is characterized by a wide spectrum of somatic, hormonal, and metabolic features. Here we report an unusual case of recurrent hypoglycemia in a 53-year-old woman with TS. Biochemical work-up following a 72h fast revealed detectable, inappropriate for low glucose insulin levels and elevated proinsulin and beta-hydroxybutyrate (BOHB) levels. MR and multiphase CT showed a solid 2.5 cm pancreatic tail mass with absent uptake in the ¹¹¹In-pentetreotide (Octreoscan) scan. Subsequent hepatic vein blood sampling after intra-arterial calcium stimulation showed sharp increase in insulin and modest increase in proinsulin levels. The patient underwent excision of the mass with resolution of symptoms. Histopathologic examination confirmed the neuroendocrine etiology of the tumor. This is, to our knowledge, the third report of TS and concomitant insulinoma. Impaired counterregulatory response to hypoglycemia in patients with TS may result in symptomatic hypoglycemia with only mild insulin elevation and elevated proinsulin in setting of hypoglycemia may be the only indication of insulinoma in these patients. BOHB levels should not be used for ruling out EHH in patients with TS.

The Natural History of Metabolic Comorbidities in Turner Syndrome from Childhood to Early Adulthood: Comparison between 45,X Monosomy and Other Karyotypes

OBJECTIVE

Patients with Turner syndrome (TS) are at increased risk for metabolic disorders. We aimed to delineate the occurrence and evolution of metabolic comorbidities in TS patients and to determine whether these differ in 45,X monosomy and other karyotypes.

METHODS

A longitudinal and cross-sectional retrospective cohort study was conducted in a tertiary pediatric endocrine unit during 1980-2016. Ninety-eight TS patients, 30 with 45,X monosomy were followed from childhood to early adulthood. Outcome measures included weight status, blood pressure (BP), glucose metabolism, and lipid profile.

RESULTS

Longitudinal analysis showed a significant change in body mass index (BMI) percentiles over time [F(3,115) = 4.8, P = 0.003]. Age was associated with evolution of elevated BP [systolic BP: odds ratio (OR) = 0.91, P = 0.003; diastolic BP: OR = 0.93, P = 0.023], impaired glucose metabolism (HbA1c: OR = 1.08, P = 0.029; impaired glucose tolerance: OR = 1.12, P = 0.029), and abnormal lipid profile (cholesterol: OR = 1.06, P = 0.01; low-density lipoprotein cholesterol: OR = 1.07, P = 0.041; high-density lipoprotein cholesterol: OR = 1.07, P = 0.033). The occurrence of metabolic comorbidities was similar in 45,X monosomy and other karyotypes. Coexistence of multiple metabolic comorbidities was significantly higher in 45,X monosomy [F(1,72) = 4.81, P = 0.032]. BMI percentiles were positively correlated with metabolic comorbidities (occurrence and number) in each patient (r = 0.35, P = 0.002 and r = 0.383, P = 0.001, respectively).

CONCLUSION

Our longitudinal study provides unique insights into the evolution of weight gain and metabolic disorders from childhood to early adulthood in TS patients. Since overweight and increasing age aggravate the risk for metabolic comorbidities, careful surveillance is warranted to prevent and control obesity already from childhood. The more prominent clustering of metabolic comorbidities in 45,X monosomy underscores the importance of a more vigorous intervention in this group.

Prolonged QT interval and cardiac arrest after a single dose of amiodarone in a woman with Turner's syndrome

Low‐dose QT‐prolonging drugs may have detrimental effects on women with Turner's syndrome. Preventive measures would be to use potential QT‐prolonging drugs with precaution and ensure that both before and during treatment, ECGs are evaluated and drug treatment stopped if the QT interval increases.

Pilot Study of Blood Pressure in Girls With Turner Syndrome: An Awareness Gap, Clinical Associations, and New Hypotheses

Cardiovascular disease is the major factor that reduces lifespan in Turner syndrome. High blood pressure (BP) is common in Turner syndrome and is the most easily treatable cardiovascular risk factor. We studied the prevalence of elevated screening systemic BP, awareness of the problem, and its clinical associations in a large group of girls attending the annual meeting of the Turner Syndrome Society of the United States. Among 168 girls aged 2 to 17 years, 42% had elevated screening BP (systolic and diastolic), yet only 8% reported a previous diagnosis of hypertension. History of aortic coarctation repair (17%) was positively associated with elevated systolic BP (52% versus 32%; P<0.05). Elevated systolic BP was positively associated with obesity (56% versus 31%; P<0.05). Because the prevalence of obesity in the studied population was similar to Center for Disease Control published data for obesity in all girls and the prevalence of increased BP is approximately twice that of the general population, the Turner syndrome phenotype/genotype probably includes an intrinsic risk for hypertension. Obesity and repaired aortic coarctation increase this risk further. There seems to be a BP awareness gap in girls with Turner syndrome. Because girls living with Turner syndrome are a sensitized population for hypertension, further study may provide clues to genetic factors leading to a better understanding of essential hypertension in the general population.

Arterial hypertension in Turner syndrome: a review of the literature and a practical approach for diagnosis and treatment

Turner syndrome is a rare chromosomal disorder with complete or partial absence of one X chromosome that only occurs in women. Clinical presentation is variable, but congenital and acquired cardiovascular diseases are frequently associated diseases that add significantly to the increased morbidity and mortality in Turner syndrome patients. Arterial hypertension is reported in 13-58% of adult Turner syndrome patients and confers an increased risk for stroke and aortic dissection. Hypertension can be present from childhood on and is reported in one-quarter of the paediatric Turner syndrome patients. This article reviews the prevalence and cause of arterial hypertension in Turner syndrome and describes the relationship between blood pressure, aortic dilation and increased cardiovascular risk. We compare current treatment strategies and also propose an integrated practical approach for the diagnosis and treatment of hypertension in Turner syndrome applicable in daily practice.

Transitions in endocrinology: treatment of Turner's syndrome during transition

Transition in health care for young patients with Turner's syndrome (TS) should be perceived as a staged but uninterrupted process starting in adolescence and moving into adulthood. As a condition associated with high risk of short stature, cardiovascular diseases, ovarian failure, hearing loss and hypothyroidism, TS requires the attention of a multidisciplinary team. In this review paper, we systematically searched the relevant literature from the last decade to discuss the array of problems faced by TS patients and to outline their optimal management during the time of transfer to adult service. The literature search identified 233 potentially relevant articles of which 114 were analysed. The analysis confirmed that all medical problems present during childhood should also be followed in adult life. Additionally, screening for hypertension, diabetes mellitus, dyslipidaemia, and osteoporosis is needed. After discharge from the paediatric clinic, there is still a long way to go.

Doppler-derived strain imaging detects left ventricular systolic dysfunction in children with Turner syndrome

OBJECTIVES

Children with Turner syndrome (TS) are at increased risk of cardiovascular disease (CVD), but associations with subclinical CVD are not well-characterized. The purpose of this study was to assess myocardial function using strain imaging (SI) by echocardiography in children with TS and without known CVD.

METHODS

The study included 48 children with TS aged 4-16 years and 20 healthy control children. Children with TS were excluded if they had a cardiac malformation, a decreased left ventricular (LV) systolic function, or any chronic disease. Each child had an echocardiographic examination with conventional echocardiography and one-dimensional longitudinal strain (1DST) echocardiography.

RESULTS

Septal and lateral systolic strain (S) and strain rate (SR) values, which are indicative of longitudinal myocardial function, were significantly decreased in TS patients. However, LV ejection fraction (LVEF) and LV fractional shortening (LVFS) was not significantly different between groups. LV mass index (LVMi), interventricular septum (IVS) thickness, LV posterior wall (LVPW) thickness, and left atrial (LA) diameter index were significantly higher in TS children compared to controls. Peak transmitral flow velocity in late diastole (peak A) was significantly higher, whereas peak transmitral flow velocity in early diastole (peak E), deceleration time (DT), and the ratio of early to late diastolic filling were significantly lower, in TS patients.

CONCLUSION

Reduced LV systolic S and SR in children with TS may indicate early myocardial dysfunction before any detectable change in LVEF.

Long QT interval in Turner syndrome--a high prevalence of LQTS gene mutations

Objectives

QT-interval prolongation of unknown aetiology is common in Turner syndrome. This study set out to explore the presence of known long QT mutations in Turner syndrome and to examine the corrected QT-interval (QTc) over time and relate the findings to the Turner syndrome phenotype.

Methods

Adult women with Turner syndrome (n = 88) were examined thrice and 68 age-matched healthy controls were examined once. QTc was measured by one blinded reader (intra-reader variability: 0.7%), and adjusted for influence of heart rate by Bazett’s (bQTc) and Hodges’s formula (hQTc). The prevalence of mutations in genes related to Long QT syndrome was determined in women with Turner syndrome and a QTc >432.0 milliseconds (ms). Echocardiographic assessment of aortic valve morphology, 24-hour blood pressures and blood samples were done.

Results

The mean hQTc in women with Turner syndrome (414.0±25.5 ms) compared to controls (390.4±17.8 ms) was prolonged (p<0.001) and did not change over time (416.9±22.6 vs. 415.6±25.5 ms; p = 0.4). 45,X karyotype was associated with increased hQTc prolongation compared to other Turner syndrome karyotypes (418.2±24.8 vs. 407.6±25.5 ms; p = 0.055). In women with Turner syndrome and a bQTc >432 ms, 7 had mutations in major Long QT syndrome genes (SCN5A and KCNH2) and one in a minor Long QT syndrome gene (KCNE2).

Conclusion

There is a high prevalence of mutations in the major LQTS genes in women with TS and prolonged QTc. It remains to be settled, whether these findings are related to the unexplained excess mortality in Turner women.

Clinical Trial Registration

NCT00624949. https://register.clinicaltrials.gov/prs/app/action/SelectProtocol/sid/S0001FLI/selectaction/View/ts/3/uid/U000099E.

Cardiovascular phenotype in Turner syndrome--integrating cardiology, genetics, and endocrinology

Cardiovascular disease is emerging as a cardinal trait of Turner syndrome, being responsible for half of the 3-fold excess mortality. Turner syndrome has been proposed as an independent risk marker for cardiovascular disease that manifests as congenital heart disease, aortic dilation and dissection, valvular heart disease, hypertension, thromboembolism, myocardial infarction, and stroke. Risk stratification is unfortunately not straightforward because risk markers derived from the general population inadequately identify the subset of females with Turner syndrome who will suffer events. A high prevalence of endocrine disorders adds to the complexity, exacerbating cardiovascular prognosis. Mounting knowledge about the prevalence and interplay of cardiovascular and endocrine disease in Turner syndrome is paralleled by improved understanding of the genetics of the X-chromosome in both normal health and disease. At present in Turner syndrome, this is most advanced for the SHOX gene, which partly explains the growth deficit. This review provides an up-to-date condensation of current state-of-the-art knowledge in Turner syndrome, the main focus being cardiovascular morbidity and mortality. The aim is to provide insight into pathogenesis of Turner syndrome with perspectives to advances in the understanding of genetics of the X-chromosome. The review also incorporates important endocrine features, in order to comprehensively explain the cardiovascular phenotype and to highlight how raised attention to endocrinology and genetics is important in the identification and modification of cardiovascular risk.

Cardiopulmonary response to exercise and cardiac assessment in patients with turner syndrome

Turner syndrome (TS) is a chromosomal disorder; however, little is known about the exercise tolerance of patients with this syndrome. The aim of the present study was to measure the maximal aerobic capacity and cardiac function using cardiopulmonary exercise testing and lung function tests and to evaluate the cardiac parameters using echocardiography in patients with TS and control subjects. A total of 50 women with TS (mean age 21.3 ± 8.5 years) and 56 age-matched controls (mean age 21.1 ± 3.7 years) were enrolled from the Pediatric Department of "Sapienza" University of Rome and underwent cardiopulmonary exercise testing, lung function testing, and echocardiography. The maximal oxygen uptake was lower in the patients with TS than in the controls (28.4 ± 4.0 vs 35.6 ± 6.2 ml/min/kg; p <0.0001). Also, the forced expiratory volume in 1 second, expressed as a percentage of the predicted value, was greater in the patients with TS than in the controls (116.2 ± 15.2% vs 102.8 ± 4.8%, p <0.0001). The patients with TS had a smaller left ventricle than did the controls. Tissue Doppler imaging revealed subclinical systolic and diastolic dysfunction in the left ventricle in those with TS but not in the controls. The left ventricular mass index was greater in the patients with TS than in the controls (38.6 ± 9.3 vs 27.2 ± 4.5 g/m(2.7), p <0.0001). In conclusion, the patients with TS had a lower maximal aerobic capacity and exercise tolerance than did the controls. The anatomic and functional cardiac aspects were peculiar to those with TS and might represent a specific cardiac phenotype.

Delayed β-cell response and glucose intolerance in young women with Turner syndrome

BACKGROUND

To investigate glucose homeostasis in detail in Turner syndrome (TS), where impaired glucose tolerance (IGT) and type 2 diabetes are frequent.

METHODS

Cross sectional study of women with Turner syndrome (TS)(n = 13) and age and body mass index matched controls (C) (n = 13), evaluated by glucose tolerance (oral and intravenous glucose tolerance test (OGTT and IVGTT)), insulin sensitivity (hyperinsulinemic, euglycemic clamp), beta-cell function (hyperglycaemic clamp, arginine and GLP-1 stimulation) and insulin pulsatility.

RESULTS

Fasting glucose and insulin levels were similar. Higher glucose responses was seen in TS during OGTT and IVGTT, persisting after correction for body weight or muscle mass, while insulin responses were similar in TS and C, despite the higher glucose level in TS, leading to an insufficient increase in insulin response during dynamic testing. Insulin sensitivity was comparable in the two groups (TS vs. control: 8.6 ± 1.8 vs. 8.9 ± 1.8 mg/kg*30 min; p = 0.6), and the insulin responses to dynamic β-cell function tests were similar. Insulin secretion patterns examined by deconvolution analysis, approximate entropy, spectral analysis and autocorrelation analysis were similar. In addition we found low IGF-I, higher levels of cortisol and norepinephrine and an increased waist-hip ratio in TS.

CONCLUSIONS

Young normal weight TS women show significant glucose intolerance in spite of normal insulin secretion during hyperglycaemic clamping and normal insulin sensitivity. We recommend regularly testing for diabetes in TS.

TRIAL REGISTRATION

Registered with http://clinicaltrials.com, ID nr: NCT00419107.

Cardiac status after childhood growth hormone treatment of Turner syndrome

CONTEXT

In Turner syndrome (TS), GH treatment is well established. Data on cardiac status after discontinuation of treatment are scarce. This study aimed to assess biventricular size and function in TS at least 6 months after discontinuation of GH treatment.

METHODS

TS patients and healthy women prospectively underwent cardiac magnetic resonance imaging. Ventricular two-dimensional tomographic cine data were acquired to obtain biventricular volume, mass, and ejection fraction. Atrioventricular valve flow measurements were performed using a two-dimensional flow-sensitized sequence. Flow velocity curves were calculated and indices of biventricular diastolic filling were derived.

RESULTS

Thirty-one patients [mean (sd) age 20 (2) yr, body surface area 1.75 (0.15) m(2), 5 (2) yr after GH discontinuation] and 23 normal control women [age 21 (2) yr, body surface area 1.80 (0.13) m(2)] were included. Compared with controls, patients had smaller mean end-diastolic volumes [right ventricle (RV), 84 (11) ml/m(2) vs. 79 (10), P = 0.02; left ventricle (LV), 81 (10) vs. 72 (9), P < 0.001], end-systolic volumes [RV 38 (7) ml/m(2) vs. 36 (6), P = 0.04; LV 34 (5) vs. 29 (4), P < 0.001], and stroke volumes [RV 46 (6) ml/m(2) vs. 43 (6), P = 0.03; LV, 47 (7) vs. 44 (4), P = 0.02]. Patients had a higher mean heart rate [79 (13) beats/min vs. 71 (10), P < 0.05]. Biventricular ejection fraction, mass, cardiac output, and diastolic filling pattern were comparable.

CONCLUSION

After discontinuation of GH treatment TS patients showed no myocardial hypertrophy and well-preserved biventricular function. Ventricular volumes were smaller in Turner patients, compared with controls, whereas mean heart rate was higher. These last observations may be part of the natural development in TS and not linked to GH treatment, which at this point we consider safe.