Coagulation and fibrinolytic disturbances are related to carotid intima thickness and arterial blood pressure in Turner syndrome

OBJECTIVE

Turner syndrome (TS) is characterized by growth retardation, hypogonadism and a high risk of cardiovascular complications and atherosclerosis; case reports suggest that thrombo-embolic complications may be present.

DESIGN

Cross-sectional study.

PATIENTS

Sixty women with TS.

MEASUREMENTS

We characterized the activities of the haemostatic system, elucidated by the assessment of a panel of clotting factors and thrombosis risk factors and related these findings to carotid intima thickness (CIMT) and blood pressure.

RESULTS

Most (81%) received hormone replacement therapy. The medians of all measured factors and inflammatory parameters were not different from normative data, but many cases displayed values of C-reactive protein (CRP) (40%), fibrinogen (15%), fibrin D-dimer (15%), factor VIII (25%), von Willebrand factor (vWF) (15%), cholesterol and liver parameters that were greater than normative limits. CRP, fibrinogen, vWF, factor VIII and liver parameters were highly and positively correlated. Haemostatic variables were positively related to both CIMT and blood pressure. The Factor V Leiden G1691A gene polymorphism heterozygosity was detected in 12·5%.

CONCLUSION

We describe a significant proportion of individual TS females having high levels of vWF, factor VIII, fibrinogen and CRP (15-40%) and an increased frequency of the Leiden mutation, with important associations with CIMT and blood pressure, suggesting that a subset of TS may have an unfavourable haemostatic balance, which may contribute to the increased risk of premature ischaemic heart disease and possibly increase the risk of deep venous and portal vein thrombosis.

Mortality in Cushing's syndrome: a systematic review and meta-analysis

CONTEXT

Data on mortality associated with Cushing's disease (CD) and Cushing's syndrome (CS) are scarce.

OBJECTIVE

To perform a systematic review and meta-analysis of mortality studies in patients with CD and CS secondary to a benign adrenal adenoma.

DATA SOURCES

A search was performed in seven electronic databases. Sixty-six articles were retrieved for analysis and 7 included in the final study. The main outcome measure was standardized mortality ratio (SMR).

STUDY ELIGIBILITY CRITERIA, PARTICIPANTS, AND INTERVENTIONS

Studies reporting SMR for patients diagnosed with CD and/or CS. Outcomes were stratified by subtype of Cushing's syndrome.

STUDY APPRAISAL AND SYNTHESIS METHODS

Studies were appraised by two authors and were synthesized using a weighted estimate based on the standard error of the SMR.

RESULTS

The weighted mean of SMR for patients with CD was 1.84 (95% confidence interval (CI): 1.28-2.65). CD patients with persistent disease after initial surgery had a SMR of 3.73 (95% CI: 2.31-6.01), whereas mortality of CD patients with initial remission did not differ significantly from the general population (SMR: 1.23 (95% CI: 0.51-2.97)). SMR for patients with a benign adrenal adenoma was 1.90 (95% CI: 0.93-3.91). Age, sex and observation time did not significantly impact mortality.

CONCLUSIONS

CD as opposed to CS due to a benign adrenal adenoma is associated with an excess mortality, which is attributed to patients in whom initial surgical cure is not obtained. This underlines the importance of a rigorous and early follow-up of newly operated patients with CD.

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.

Normal tempo of bone formation in Turner syndrome despite signs of accelerated bone resorption

AIMS

To evaluate area bone mineral density (aBMD) and volumetric BMD (vBMD) by dual-energy X-ray absorptiometry, and relations to bone markers and hormones in adolescent women with Turner syndrome (TS).

METHODS

Cross-sectional study in TS patients (n = 37, 16.7 ± 3.4 years) and control group (n = 49), assessed by dual-energy X-ray absorptiometry, bone markers and hormones. TS patients were divided into a young group receiving ('ongoing') GH (n = 15) and an older group previously receiving ('previous') GH (n = 22).

RESULTS

vBMD(spine) was similar in 'ongoing GH' TS, but higher in 'previous GH' TS, compared to controls. vBMD(hip) was lower in 'ongoing GH' TS, but similar in 'previous GH'. z scores for aBMD were uniformly reduced in 'ongoing TS', but near-normalized in 'previous GH' TS. Bone formation and resorption markers were increased in 'ongoing GH' TS, while 'previous GH' TS had elevated bone resorption markers.

CONCLUSION

BMD increased in parallel with age in TS patients receiving optimal estradiol replacement therapy and GH according to consensus guidelines, and in controls. Young TS undergoing pubertal induction and still receiving GH have lower z score BMD than older TS patients receiving hormonal replacement therapy, where a near-normalization of BMD was achieved. TS patients previously receiving GH showed signs of increased bone resorption.

Long-term DHEA substitution in female adrenocortical failure, body composition, muscle function, and bone metabolism: a randomized trial

CONTEXT

Adrenal derived androgens are low in women with adrenal failure. The physiological consequences of substitution therapy are uncertain.

OBJECTIVE

To investigate the effects of DHEA substitution in women with adrenal failure on body composition, fuel metabolism, and inflammatory markers. DESIGN, PARTICIPANTS AND INTERVENTION: In this study, ten female patients (median age 38.5 years, range 28-52) with adrenal failure were treated with DHEA 50 mg for 6 months in a double-blind, randomized, placebo-controlled, and crossover study. The participants underwent dual-energy X-ray absorptiometry (DXA) scan, computed tomography scan of abdominal fat, indirect calorimetry, bicycle ergometry, muscle and fat biopsies, and blood samples.

RESULTS

Baseline androgens were normalized to fertile range during active treatment. Anthropometric data were unaffected, but lean body mass (LBM) slightly increased compared with placebo (delta LBM (kg) placebo versus DHEA: -0.48±6.1 vs 1.6±3.4, P=0.02) with no alterations in total or abdominal fat mass. PTH increased with DHEA, but no significant changes were observed in other bone markers or in bone mineral content. The mRNA levels of markers of tissue inflammation (adiponectin, interleukin 6 (IL6), IL10, monocyte chemoattractant protein 1, and tumor necrosis factor α) in fat and muscle tissue were unaffected by DHEA treatment, as was indirect calorimetry and maximal oxygen uptake. A high proportion of self-reported seborrheic side effects were recorded (60%).

CONCLUSION

In female adrenal failure, normalization of androgens with DHEA 50 mg for 6 months had no effects on muscle, fat, and bone tissue and on fuel metabolism in this small study. A small increase in LBM was observed. Treatment was associated with a high frequency of side effects.

Body composition, metabolic syndrome and type 2 diabetes in Klinefelter syndrome

Klinefelter syndrome (KS) affects 1:660 men, making it the most common sex-chromosome disorder in man, and is a common cause of infertility, hypogonadism and learning disability. Men with KS are described as tall, slim, narrow shouldered, broad hipped, with hypergonadotropic hypogonadism and small testes, and recently the description has been expanded to include increased risk of the metabolic syndrome, type 2 diabetes and an unfavourable change in body composition, with accumulation of body fat and decreased muscle mass and a concomitant decrease in insulin sensitivity, muscle strength and oxygen consumption capacity. Here, we review the data on body composition, bone turnover, liver function, insulin resistance and metabolic syndrome in relation to testosterone in both patients with KS and normal men. Treatment with testosterone in hypogonadal men (other than KS) improves body composition in both clinical and experimental studies. Despite the lack of such studies in KS, we recommend testosterone treatment to patients with KS with low serum testosterone or increased LH and change in body composition and thus possibly prevent common diseases like type 2 diabetes, osteoporosis and heart disease.

CONCLUSION

Preventable causes of the increased morbidity and mortality, such as osteoporosis, chronic obstructive airway disease or type 2 diabetes, should be screened for. Despite the lack of randomized controlled studies, we recommend testosterone treatment in case of increased LH or low serum testosterone, and weight reduction programmes if overweight.

Morbidity and mortality in Klinefelter syndrome (47,XXY)

Klinefelter syndrome (KS) (47,XXY) is the most common sex chromosome disorder in man and is a relatively common cause of male infertility and hypogonadism. The syndrome has been known since 1942, and many reports of different diseases associated with KS have been reported since that, but a more systematic knowledge about the long-term outcome was not described until the last decade, where nation-wide epidemiological studies were reported from Britain and Denmark. We here review the epidemiological data from two cohorts of patients with KS in Denmark and Britain, showing a significant increase in both mortality and morbidity from a variety of different causes. Mortality was increased by 50% (SMR 1.5 or HR 1.4) corresponding to a median loss of approximately 2 years. The risk of being admitted to hospital with any diagnosis was increased by 70%. The underlying reason for the poorer health in KS may be caused by interaction of genetic, hormonal and socio-economic factors.

CONCLUSION

Both morbidity and mortality are significantly increased in Klinefelter syndrome with a 50% increase in mortality risk and a 70% increase in risk of being admitted to hospital.

Bone mineral density in Klinefelter syndrome is reduced and primarily determined by muscle strength and resorptive markers, but not directly by testosterone

SUMMARY

Klinefelter syndrome (KS) patients have lower bone mineral density (BMD) at the spine, hip and forearm compared to healthy subjects, but frank osteoporosis is not common. Muscle strength and bone markers predicted BMD but KS itself and serum testosterone did not. Low vitamin D and high PTH were frequent among KS.

INTRODUCTION

The long-term consequence of KS on bone health is not well described. The objective of this study is to investigate the regional BMD and its determinants in KS.

METHODS

This is a cross-sectional study. BMD at the spine, hip and forearm are measured by DXA and correlated to biochemical markers of bone turnover, vitamin D metabolites, PTH, sex hormones, growth factors as well as muscle strength and anthropometric measures. The setting is at a university clinical research centre. The study involves 70 adult KS patients and 71 age-matched healthy subjects.

RESULTS

In KS, BMD was universally lowered in all regions. Markers of bone formation or bone resorption were not altered in KS, but 25-OH-Dvitamin was lower (55 vs. 82 nmol/L, p < 0.0001) than in healthy subjects. Significantly more KS patients had low BMD (Z-scores below -2) at the forearm (15 KS vs. two healthy subjects, p = 0.001) but not at the spine or hip. Muscle strength (bicep and quadriceps) was lower among KS patients. Multivariate analysis revealed that muscle strength, treatment with testosterone (ever/never), age at diagnosis, SHBG, bone-specific alkaline phosphatase and 1CTP were all independent predictors of BMD, but androgens was not.

CONCLUSIONS

KS patients had lower BMD at the spine, hip and forearm compared to age-matched healthy subjects, but frank osteoporosis was not common. Muscle strength, previous history of testosterone treatment, age at diagnosis and bone markers were predictors of BMD, but testosterone was not. Signs of secondary hyperparathyroidism were present among KS. Dietary intake of vitamin D or sun exposure may be lower in KS patients.

Dilation of the ascending aorta in Turner syndrome - a prospective cardiovascular magnetic resonance study

BACKGROUND

The risk of aortic dissection is 100-fold increased in Turner syndrome (TS). Unfortunately, risk stratification is inadequate due to a lack of insight into the natural course of the syndrome-associated aortopathy. Therefore, this study aimed to prospectively assess aortic dimensions in TS.

METHODS

Eighty adult TS patients were examined twice with a mean follow-up of 2.4 ± 0.4 years, and 67 healthy age and gender-matched controls were examined once. Aortic dimensions were measured at nine predefined positions using 3D, non-contrast and free-breathing cardiovascular magnetic resonance. Transthoracic echocardiography and 24-hour ambulatory blood pressure were also performed.

RESULTS

At baseline, aortic diameters (body surface area indexed) were larger at all positions in TS. Aortic dilation was more prevalent at all positions excluding the distal transverse aortic arch. Aortic diameter increased in the aortic sinus, at the sinotubular junction and in the mid-ascending aorta with growth rates of 0.1 - 0.4 mm/year. Aortic diameters at all other positions were unchanged. The bicuspid aortic valve conferred higher aortic sinus growth rates (p < 0.05). No other predictors of aortic growth were identified.

CONCLUSION

A general aortopathy is present in TS with enlargement of the ascending aorta, which is accelerated in the presence of a bicuspid aortic valve.

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.

Serum levels of anti-Müllerian hormone as a marker of ovarian function in 926 healthy females from birth to adulthood and in 172 Turner syndrome patients

CONTEXT

In adult women, anti-Müllerian hormone (AMH) is related to the ovarian follicle pool. Little is known about AMH in girls.

OBJECTIVE

The objective of the study was to provide a reference range for AMH in girls and adolescents and to evaluate AMH as a marker of ovarian function.

SETTING

The study was conducted at a tertiary referral center for pediatric endocrinology.

MAIN OUTCOME MEASURES

We measured AMH in 926 healthy females (longitudinal values during infancy) as well as in 172 Turner syndrome (TS) patients according to age, karyotype (A: 45,X; B: miscellaneous karyotypes; C: 45,X/46,XX), and ovarian function (1: absent puberty; 2: cessation of ovarian function; 3: ongoing ovarian function).

RESULTS

AMH was undetectable in 54% (38 of 71) of cord blood samples (<2; <2-15 pmol/liter) (median; 2.5th to 97.5th percentile) and increased in all (37 of 37) infants from birth to 3 months (15; 4.5-29.5 pmol/liter). From 8 to 25 yr, AMH levels were stable (19.9; 4.7-60.1 pmol/liter), with the lower level of the reference range clearly above the detection limit. AMH levels were associated with TS-karyotype groups (median A vs. B: <2 vs. 3 pmol/liter, P = 0.044; B vs. C: 3 vs. 16 pmol/liter, P < 0.001) as well as with ovarian function (absent puberty vs. cessation of ovarian function: <2 vs. 6 pmol/liter, P = 0.004; cessation of ovarian function vs. ongoing ovarian function: 6 vs. 14 pmol/liter, P = 0.001). As a screening test of premature ovarian failure in TS, the sensitivity and specificity of AMH less than 8 pmol/liter was 96 and 86%, respectively.

CONCLUSION

AMH seems to be a promising marker of ovarian function in healthy girls and TS patients.

Acute estrogen exposure does not affect basal very low-density lipoprotein-triglyceride production or oxidation in postmenopausal women

CONTEXT

Long-term hormone replacement therapy (HRT) with estradiol (E(2)) is associated with an altered lipid profile including unfavorable increases in triglyceride (TG) concentrations and augmented hepatic very low-density lipoprotein (VLDL)-TG production. There are indications that this effect of estrogens may be immediate.

OBJECTIVE

To study the in vivo effect of a single dose of E(2) on VLDL-TG kinetics and oxidation in humans.

METHODS

Eight healthy, postmenopausal women were given a single dose of either placebo or E(2) (4 mg) orally. VLDL-TG kinetics was assessed by a 240-min primed-continuous infusion of ex vivo labeled [1-(14)C]triolein-labeled VLDL. Fractional and absolute VLDL-TG oxidation was determined by hyamin trapping of exhaled (14)C label. Indirect calorimetry provided measurements of lipid oxidation.

RESULTS

Administration of 4 mg of E(2) orally rapidly increased plasma E(2) concentrations from below detection threshold to premenopausal levels. Free fatty acids (FFA) and TG concentrations were unaltered. No immediate effect was observed on either VLDL-TG production (placebo versus E(2)): 20.0+/-12.4 vs 24.1+/-10.7 micromol/min, P=0.33; VLDL-TG oxidation: 12.3+/-10.9 vs 12.6+/-5.6 micromol/min, P=0.93); or VLDL-TG clearance rates: 51.4+/-16.8 vs 64.9+/-28.8 ml/min, P=0.34).

CONCLUSIONS

Short-term E(2) elevation does not affect VLDL-TG production, oxidation, or clearance in humans. We therefore propose that HRT-associated dyslipidemia has a gradual rather than immediate onset.

Increased number of sex chromosomes affects height in a nonlinear fashion: a study of 305 patients with sex chromosome aneuploidy

Tall stature and eunuchoid body proportions characterize patients with 47,XXY Klinefelter syndrome, whereas patients with 45,X Turner syndrome are characterized by impaired growth. Growth is relatively well characterized in these two syndromes, while few studies describe the growth of patients with higher grade sex chromosome aneuploidies. It has been proposed that tall stature in sex chromosome aneuploidy is related to an overexpression of SHOX, although the copy number of SHOX has not been evaluated in previous studies. Our aims were therefore: (1) to assess stature in 305 patients with sex chromosome aneuploidy and (2) to determine the number of SHOX copies in a subgroup of these patients (n = 255) these patients and 74 healthy controls. Median height standard deviation scores in 46,XX males (n = 6) were -1.2 (-2.8 to 0.3), +0.9 (-2.2 to +4.6) in 47,XXY (n = 129), +1.3 (-1.8 to +4.9) in 47,XYY (n = 44), +1.1 (-1.9 to +3.4) in 48,XXYY (n = 45), +1.8 (-2.0 to +3.2) in 48,XXXY (n = 9), and -1.8 (-4.2 to -0.1) in 49,XXXXY (n = 10). Median height standard deviation scores in patients with 45,X (n = 6) were -2.6 (-4.1 to -1.6), +0.7 (-0.9 to +3.2) in 47,XXX (n = 40), -0.6 (-1.9 to +2.1) in 48,XXXX (n = 13), and -1.0 (-3.5 to -0.8) in 49,XXXXX (n = 3). Height increased with an increasing number of extra X or Y chromosomes, except in males with five, and in females with four or five sex chromosomes, consistent with a nonlinear effect on height.

Diagnosis and mortality in 47,XYY persons: a registry study

Background

Sex chromosomal abnormalities are relatively common, yet many aspects of these syndromes remain unexplored. For instance epidemiological data in 47,XYY persons are still limited.

Methods

Using a national Danish registry, we identified 208 persons with 47,XYY or a compatible karyotype, whereof 36 were deceased; all were diagnosed from 1968 to 2008. For further analyses, we identified age matched controls from the male background population (n = 20,078) in Statistics Denmark. We report nationwide prevalence data, data regarding age at diagnosis, as well as total and cause specific mortality data in these persons.

Results

The average prevalence was 14.2 47,XYY persons per 100,000, which is reduced compared to the expected 98 per 100,000. Their median age at diagnosis was 17.1 years. We found a significantly decreased lifespan from 77.9 years (controls) to 67.5 years (47,XYY persons). Total mortality was significantly increased compared to controls, with a hazard ratio of 3.6 (2.6-5.1). Dividing the causes of deaths according to the International Classification of Diseases, we identified an increased hazard ratio in all informative chapters, with a significantly increased ratio in cancer, pulmonary, neurological and unspecified diseases, and trauma.

Conclusion

We here present national epidemiological data regarding 47,XYY syndrome, including prevalence and mortality data, showing a significantly delay to diagnosis, reduced life expectancy and an increased total and cause specific mortality.

Health status in women with Turner syndrome: a questionnaire study on health status, education, work participation and aspects of sexual functioning

CONTEXT

Turner syndrome (TS) is a complex medical condition with specific cognitive and psychosocial characteristics and frequent medical morbidity. Few studies have investigated the influence this has on health status, education and ability to work.

OBJECTIVE

To explore health status, level of education, work participation, medical conditions, physical activity, satisfaction with life and aspects of sexual functioning in adult TS women and compare with a matched control group.

DESIGN

A questionnaire was sent to 168 adult women with TS >18 years registered in a database of Frambu Resource Centre for Rare Disorders and The TS Association in Norway. We assessed health status with Short Form 36, education with Norwegian Standard Classification of Education, and employment with The General Nordic Questionnaire. Life satisfaction was measured with LiSat-9, and questions on psychological strain during life phases were included.

RESULTS

Eighty women with TS (34.0 +/- 11.7 years) and 214 controls (32.9 +/- 10.6) responded. The TS group reported significantly more health problems and impaired health status in the two subscales "physical functioning" and "general health" (P < 0.001). Level of education and work participation was similar among TS and controls. TS moved away from their parents' home later than controls (20.4 +/- 4.0 vs. 18.7 +/- 2.1, P = 0.001). Age at sexual debut differed significantly (21.2 +/- 4.3 vs. 17.3 +/- 2.4 years, P < 0.001).

CONCLUSION

TS attains the same level of education and level of employment as controls, they report more frequent occurrence of medical conditions, but scored lower on only two subscales in the SF-36. Despite considerable medical morbidity, TS seem to cope well with life.

Aortic dimensions in girls and young women with turner syndrome: a magnetic resonance imaging study

This study aimed to determine the dimensions of the thoracic aorta and the predictors of aortic dimensions in girls and young women with Turner syndrome (TS). A cross-sectional study was performed at a secondary care center. The study compared 41 TS patients with 50 healthy age-matched control subjects. The mean age of the patients was 17 +/- 3.3 years. Magnetic resonance imaging was performed for all the patients. The thoracic aortic diameters of the patients were measured at nine positions. Adjustment for body surface area (BSA) was performed. The outcome for the patients was measured in terms of absolute and BSA-adjusted aortic dilation. In TS, both the absolute and the BSA-adjusted mean aortic diameters were smaller than or comparable with those of the control subjects. However, individual aortic dilation at one to four positions was found in four TS patients according to the uncorrected data and in five TS patients after BSA-adjustment. The aortic diameters correlated with height, weight, body mass index (BMI), and BSA at all positions (R = 0.34-0.60; all p < 0.04). The diameters of the aortic arch and the descending aorta correlated with a history of aortic coarctation (R = 0.35-0.52; p < 0.03). The presence of bicuspid aortic valves correlated at the descending part of the aorta (R = 0.38; p < 0.03). The mean thoracic aortic dimensions were not enlarged in girls or young TS patients. The BSA predicted aortic size at all positions. The prevalence of aortic dilation and aneurysm was lower in this population of girls and younger women with TS than in older TS populations.

Klinefelter's syndrome, type 2 diabetes and the metabolic syndrome: the impact of body composition

Klinefelter's syndrome (KS) is the most common sex-chromosome disorder in men, affecting approximately 1:660 men, and is a rather common cause of infertility, hypogonadism and learning disability. Traditionally, men with KS have been described as tall, slim, narrow shouldered, broad hipped, with hypergonadotrophic hypogonadism and small testes. Recent studies showed an increased risk of diabetes and an unfavourable change in body composition; with accumulation of body fat and decreased muscle mass and a concomitant decrease in insulin sensitivity, muscle strength and oxygen consumption capacity. Here, we review the data on body composition, insulin resistance and metabolic syndrome in relation to testosterone in both KS patients and normal men. Treatment with testosterone in hypogonadal states (other than KS) seems to improve body composition in both clinical and experimental studies. Despite the lack of such studies in KS, we recommend testosterone treatment to KS patients with low serum testosterone or increased LH and change in body composition.

Thoracic aortopathy in Turner syndrome and the influence of bicuspid aortic valves and blood pressure: a CMR study

BACKGROUND

To investigate aortic dimensions in women with Turner syndrome (TS) in relation to aortic valve morphology, blood pressure, karyotype, and clinical characteristics.

METHODS AND RESULTS

A cross sectional study of 102 women with TS (mean age 37.7; 18-62 years) examined by cardiovascular magnetic resonance (CMR- successful in 95), echocardiography, and 24-hour ambulatory blood pressure. Aortic diameters were measured by CMR at 8 positions along the thoracic aorta. Twenty-four healthy females were recruited as controls. In TS, aortic dilatation was present at one or more positions in 22 (23%). Aortic diameter in women with TS and bicuspid aortic valve was significantly larger than in TS with tricuspid valves in both the ascending (32.4 +/- 6.7 vs. 26.0 +/- 4.4 mm; p < 0.001) and descending (21.4 +/- 3.5 vs. 18.8 +/- 2.4 mm; p < 0.001) aorta. Aortic diameter correlated to age (R = 0.2 - 0.5; p < 0.01), blood pressure (R = 0.4; p < 0.05), a history of coarctation (R = 0.3; p = 0.01) and bicuspid aortic valve (R = 0.2-0.5; p < 0.05). Body surface area only correlated with descending aortic diameter (R = 0.23; p = 0.024).

CONCLUSIONS

Aortic dilatation was present in 23% of adult TS women, where aortic valve morphology, age and blood pressure were major determinants of the aortic diameter.

Effect of sex hormone treatment on circulating adiponectin and subforms in Turner and Klinefelter syndrome

BACKGROUND

Sex hormones have been shown to influence levels of adiponectin. Furthermore, testosterone has been shown to alter the subform distribution of adiponectin, whereas the effects of oestradiol are equivocal. We investigated the impact of sex hormone replacement therapy (HRT) on circulating adiponectin and its subforms, fasting lipids and measures of insulin sensitivity in Turner syndrome (TS) and Klinefelter syndrome (KS) respectively.

MATERIALS AND METHODS

We compared eight young TS patients on and off 2 months of HRT vs. eight age- and body mass index (BMI) matched healthy females as well as 19 untreated KS patients vs. 20 testosterone treated KS patients vs. 20 age and BMI matched healthy males. Total adiponectin and adiponectin subforms separated by fast protein liquid chromatography were measured using an in-house assay. In addition, fasting levels of insulin, glucose and homeostasis model assessment estimates were determined.

RESULTS

In TS, total adiponectin levels were 10.5 +/- 3.1 (mean +/- SD) vs. 12.8 +/- 3.5 mg L(-1) (P = 0.02) and high molecular weight (HMW) adiponectin 5.8 +/- 2.7 and 6.8 +/- 1.9 mg L(-1) (P = 0.02) on and off HRT respectively. Irrespective of HRT, total adiponectin and HMW adiponectin were similar to control values. In KS, total adiponectin levels were 6.5 (3.0-24.2) (median and range) and 9.3 (4.3-14.3) mg L(-1) (P = NS) and HMW adiponectin was 2.5 (0.5-16.0) and 4.6 (1.3-8.6) mg L(-1) (P = NS) with and without testosterone treatment respectively, and similar to controls.

CONCLUSION

Short time HRT suppressed HMW and total adiponectin levels in TS patients. Testosterone treatment in KS patients had no effect on these parameters. In both groups of patients either adiponectin or the HMW subform seems to play no greater role in reflecting or mediating insulin sensitivity. Our data indicates that in patients with TS and KS, sex hormones have different effects on circulating adiponectin and its HMW subform than previously reported in other sex hormone deficient patients and healthy subjects.

Discontinuation of hormone replacement therapy in young GH-treated hypopituitary women increases liver enzymes

OBJECTIVE

Hypopituitarism, often characterized by hypogonadism, is associated with central obesity, increased cardiovascular and endocrine morbidity and mortality. In Turner syndrome, which is also characterized by hypogonadism liver enzymes are often elevated, but readily suppressed by a short course of hormone replacement therapy (HRT). We investigated the effect of HRT on liver enzymes, lipid levels and measures of insulin sensitivity 26 in hypopituitary women.

DESIGN

We studied 26 hypopituitary women (age 38.8+/-11.0 (mean+/-SD years), BMI 27.4+/-5.1kg/m(2)) during HRT and 28days off therapy.

METHODS

We measured liver enzymes, fasting levels of lipids, insulin and glucose as well as adiponectin and leptin levels. Body composition was assessed by means of anthropometry and bioimpedance.

RESULTS

Alanine transaminase (ALT) and aspartate transaminase (AST) increased after discontinuation of HRT (ALT; treated: 22.3+/-11.5 vs. untreated: 27.1+/-11.1 (U/L) (P<0.02); AST; treated: 20.4+/-6.1 vs. untreated: 24.6+/-8.9 (U/L) (P<0.002)), whereas other liver function tests remained unchanged. Measures of insulin sensitivity and fasting lipids were also unaffected by HRT, whereas leptin levels decreased with cessation of HRT (leptin; treated: 23 (8-71) vs. untreated: 20 (8-64) (mug/L) (P<0.0005)).

CONCLUSION

Short time discontinuation of HRT in young hypopituitary women increased liver enzymes, whereas measures of insulin sensitivity and lipid levels remained unchanged. We speculate that the estrogen component of HRT has beneficial effects on hepatic metabolism through various pathways. Further studies including liver imaging and with a time-dependent design are needed to clarify the role of HRT on liver enzyme levels, metabolic variables and liver fat content.

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

CONTEXT

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

OBJECTIVE

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

DESIGN

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

SETTING

Tertiary hospital.

PARTICIPANTS

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

RESULTS

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

CONCLUSION

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

Hypothyroidism secondary to hypothalamic-pituitary dysfunction may be part of the phenotype in klinefelter syndrome: a case-control study

CONTEXT

Klinefelter syndrome (KS) may involve a number of abnormalities besides the characteristic testicular insufficiency. Some studies have suggested that thyroid abnormalities may be common, but this has not been clarified.

DESIGN

A case-control study of men with KS (n = 75) compared with age-matched men from the general population (n = 75) was organized, and thyroid function, thyroid volume by ultrasonography, and thyroid antibodies were examined.

RESULTS

Men with KS were on average taller and heavier and tended to have a higher body mass index than the men in the control group. Serum free T(4) (fT4) was lower in men with KS than controls [mean (sd): 16.3 (2.35) vs. 17.6 (1.75) pmol/liter; P < 0.001], with clustering in or just below the lower part of the reference range for the assay. The ratio fT4 to free T(3) was low in KS (P < 0.001), whereas no differences between groups were observed in TSH, free T(3), TSH to fT4 ratio, thyroid volume, or the prevalence of thyroid antibodies. No difference in any of the variables were observed between testosterone-treated and untreated KS men. Adjustment for differences in height, weight, and concomitant disease in multivariate models did not alter the results.

CONCLUSIONS

Men with KS had a general shift toward lower values in distribution of serum fT4 with no compensatory increase in serum TSH. The most likely mechanism is a decrease or change in set point of thyrotroph control of thyroid function.

Increased prevalence of autoimmunity in Turner syndrome--influence of age

Individuals with Turner syndrome (TS) are prone to develop autoimmune conditions such as coeliac disease (CD), thyroiditis and type 1 diabetes (T1DM). The objective of the present study was to examine TS of various karyotypes for autoantibodies and corresponding diseases. This was investigated in a prospective cross-sectional study of Danish TS patients (n = 107, median age 36.7 years, range: 6-60 years). A medical history was recorded and a blood sample was analysed for autoantibodies against gliadin, transglutaminase, adrenal cortex, intrinsic factor, anti-thyroid peroxidase (anti-TPO) and glutamic-acid-decarboxylase 65 (GAD-65). Autoantibodies were present in 58% (n = 61) of all patients, whereof 18% (11) had autoantibodies targeting more than one organ. Patients with autoantibodies were significantly older than those without (P = 0.001). Anti-TPO was present in 45% (48) of patients, of whom 33% (16) were hypothyroid. Overall, 18% (19) presented with CD autoantibodies, of whom 26% (five) had CD. Anti-TPO and CD autoantibodies co-existed in 9% (10). Immunoglobulin A deficiency was found in 3% (three) of patients, who all had CD autoantibodies without disease. Among four patients with anti-GAD-65 none had T1DM, but two were classified as having T2DM. One patient had adrenocortical autoantibodies but not adrenal failure. Autoantibodies against intrinsic factor were absent. Anti-GAD-65 was increased in isochromosomal karyotypes (3/23 versus 1/84, P = 0.008) with no other association found between autoantibodies and karyotype. In conclusion, TS girls and women face a high prevalence of autoimmunity and associated disease with a preponderance towards hypothyroidism and CD. Thus, health care providers dealing with this patient group should be observant and test liberally for these conditions even before clinical symptoms emerge.

Left ventricular dysfunction in Klinefelter syndrome is associated to insulin resistance, abdominal adiposity and hypogonadism

OBJECTIVE

Epidemiological data suggest there is an increased risk of dying from heart disease among patients with Klinefelter syndrome (KS). Due to high prevalence of hypogonadism and metabolic syndrome, we speculated that patients with KS may have subclinical changes in the left ventricular function. Therefore, the aim was to assess left ventricular long axis function by tissue Doppler echocardiography in patients with KS and relate these findings to the metabolic status and testosterone levels.

DESIGN

Cross-sectional study. Out-patient clinic.

PATIENTS

We investigated 25 unselected patients with KS, recruited from endocrine and fertility clinics. Twenty-five age-matched males served as controls.

MEASUREMENTS

Left ventricular systolic long axis function (velocities and strain rate) assessed by tissue Doppler echocardiography related to free testosterone, fasting values of plasma glucose, insulin, homeostasis model assessment (HOMA)-index, cholesterol and triglycerides in addition to dual energy X-ray absorptiometry (DEXA) scan derived assessment of truncal body fat.

RESULTS

The long axis function was significantly reduced in patients with KS (peak systolic velocities 4.4 +/- 1.3 vs. 5.3 +/- 1.0 cm/s, P < 0.01 and strain rate -1.3 +/- 0.3 vs.-1.6 +/- 0.3 s(-1), P < 0.01). However, the ventricular dysfunction was mainly attributed KS patients with metabolic syndrome. The peak systolic velocities were significantly correlated to truncal body fat (r = -0.72, P < 0.01) and free testosterone (r = 0.63, P < 0.01), but uncorrelated to plasma glucose, insulin and HOMA-index.

CONCLUSION

Systolic long axis function is decreased in patients with KS and metabolic syndrome. The decrease in myocardial systolic function was significantly related to truncal body fat and hypogonadism, but not correlated to insulin sensitivity.

Turner syndrome and clinical treatment

BACKGROUND

Turner syndrome (TS) is a genetic disorder associated with abnormalities of the X chromosome, occurring in about 50 per 100,000 liveborn girls. TS is usually associated with reduced adult height, gonadal dysgenesis and thus insufficient circulating levels of female sex steroids leading to premature ovarian failure and infertility. The average intellectual performance is within the normal range. New insight into genetics, epidemiology, cardiology, endocrinology and metabolism from a number of recent studies will be included in this review.

SOURCES OF DATA

For this review we concentrated on all papers published on TS with special emphasis on the most recent literature. Also papers relating to cardiology, especially aortic dissection, paediatrics and the effects of estradiol in other conditions were considered. The main source was PubMed and the major endocrinology and cardiology journals.

AREAS OF AGREEMENT

Treatment with growth hormone (GH) during childhood and adolescence allows a considerable gain in adult height. SHOX deficiency explains some of the phenotypic characteristics in TS, principally short stature. Puberty has to be induced in most cases, and female sex hormone replacement therapy (HRT) is given during adult years. Morbidity and mortality is increased, especially due to the risk of dissection of the aorta and other cardiovascular (CV) diseases, as well as the risk of type 2 diabetes, osteoporosis and thyroid disease.

AREAS OF CONTROVERSY

The proper dose of HRT with female sex steroids has not been established, and, likewise, benefits and/or drawbacks from HRT have not been thoroughly evaluated. In most countries it seems that the transition period from paediatric to adult care is especially vulnerable and the proper framework for transition has not been established. Today, most treatment recommendations are based on expert opinion and are unfortunately not evidence based, although more areas, such as GH treatment for increasing height, are well founded.

GROWING POINTS

The description of adult life with TS has been broadened and medical, social and psychological aspects are being added at a compelling pace.

AREAS TIMELY FOR DEVELOPING RESEARCH

Proper care during adulthood should be studied, since most morbidity potentially is amenable to proper care. Especially, interventional strategy and follow-up with respect to congenital CV malformations, as well as secondary CV disease, have to be developed and new treatment algorithms have to be studied. In summary, TS is a condition associated with a number of diseases and conditions, which need the attention of a multi-disciplinary team.

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.

Effects of cortisol on carbohydrate, lipid, and protein metabolism: studies of acute cortisol withdrawal in adrenocortical failure

CONTEXT

Cortisol is an important catabolic hormone, but little is known about the metabolic effects of acute cortisol deficiency.

OBJECTIVE

The objective of the study was to test whether clinical symptoms of weight loss, fatigue, and hypoglycemia could be explained by altered energy expenditure, protein metabolism, and insulin sensitivity during cortisol withdrawal in adrenocortical failure.

DESIGN, PARTICIPANTS, AND INTERVENTION

We studied seven women after 24-h cortisol withdrawal and during replacement control during a 3-h basal period and a 3-h glucose clamp.

RESULTS

Cortisol withdrawal generated cortisol levels close to zero, a 10% decrease in basal energy expenditure, increased TSH and T(3) levels, and increased glucose oxidation. Whole-body glucose and phenylalanine turnover were unaltered, but forearm phenylalanine turnover was increased. During the clamp glucose, infusion rates rose by 70%, glucose oxidation rates increased, and endogenous glucose production decreased. Urinary urea excretion decreased by 40% over the 6-h study period.

CONCLUSIONS

Cortisol withdrawal increased insulin sensitivity in terms of increased glucose oxidation and decreased endogenous glucose production; this may induce hypoglycemia in adrenocortical failure. Energy expenditure and urea loss decreased, indicating that weight and muscle loss in Addison's disease is caused by other mechanisms, such as decreased appetite. Increased muscle protein breakdown may amplify the loss of muscle protein.

Klinefelter syndrome in clinical practice

Klinefelter syndrome is the most common sex-chromosome disorder; it affects approximately one in every 660 men. This syndrome is characterized by the presence of one or more extra X chromosomes, and the karyotype 47,XXY is the most prevalent type. The 'prototypic' man with Klinefelter syndrome has traditionally been described as tall, with narrow shoulders, broad hips, sparse body hair, gynecomastia, small testicles, androgen deficiency, azoospermia and decreased verbal intelligence. A less distinct phenotype has, however, been described. Klinefelter syndrome is an underdiagnosed condition; only 25% of the expected number of patients are diagnosed, and of these only a minority are diagnosed before puberty. Patients with Klinefelter syndrome should be treated with lifelong testosterone supplementation that begins at puberty, to secure proper masculine development of sexual characteristics, muscle bulk and bone structure, and to prevent the long-term deleterious consequences of hypogonadism; however, the optimal testosterone regimen for patients with Klinefelter syndrome remains to be established.

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.

The metabolic syndrome is frequent in Klinefelter's syndrome and is associated with abdominal obesity and hypogonadism

OBJECTIVE

Klinefelter's syndrome is associated with an increased prevalence of diabetes, but the pathogenesis is unknown. Accordingly, the aim of this study was to investigate measures of insulin sensitivity, the metabolic syndrome, and sex hormones in patients with Klinefelter's syndrome and an age-matched control group. RESEARCH DESIGN AN METHODS: In a cross-sectional study, we examined 71 patients with Klinefelter's syndrome, of whom 35 received testosterone treatment, and 71 control subjects. Body composition was evaluated using dual-energy X-ray absorptiometry scans. Fasting blood samples were analyzed for sex hormones, plasma glucose, insulin, C-reactive protein (CRP), and adipocytokines. We analyzed differences between patients with untreated Klinefelter's syndrome and control subjects and subsequently analyzed differences between testosterone-treated and untreated Klinefelter's syndrome patients.

RESULTS

Of the patients with Klinefelter's syndrome, 44% had metabolic syndrome (according to National Cholesterol Education Program/Adult Treatment Panel III criteria) compared with 10% of control subjects. Insulin sensitivity (assessed by homeostasis model assessment 2 modeling), androgen, and HDL cholesterol levels were significantly decreased, whereas total fat mass and LDL cholesterol, triglyceride, CRP, leptin, and fructosamine levels were significantly increased in untreated Klinefelter's syndrome patients. In treated Klinefelter's syndrome patients, LDL cholesterol and adiponectin were significantly decreased, whereas no difference in body composition was found in comparison with untreated Klinefelter's syndrome patients. Multivariate analyses showed that truncal fat was the major determinant of metabolic syndrome and insulin sensitivity.

CONCLUSIONS

The prevalence of metabolic syndrome was greatly increased, whereas insulin sensitivity was decreased in Klinefelter's syndrome. Both correlated with truncal obesity. Hypogonadism in Klinefelter's syndrome may cause an unfavorable change in body composition, primarily through increased truncal fat and decreased muscle mass. Testosterone treatment in Klinefelter's syndrome only partly corrected the unfavorable changes observed in untreated Klinefelter's syndrome, perhaps due to insufficient testosterone doses.

Incidence of GH deficiency - a nationwide study

OBJECTIVE

Data on incidence rates are scarce in GH deficiency (GHD). Here, we estimate the incidence rate in childhood onset (CO) and adult onset (AO) GHD in Denmark.

DESIGN

We used three national registries to identify 9131 cases with an increased risk of GHD. Date of entry was defined using the date when a registration had taken place and when a date of sufficient information could be defined from a thorough examination of a record of a GHD patient, which ever came last. We considered date of entry as the incident date.

METHODS

Sex-specific incidence rates of GHD in children and adults using the background population as reference.

RESULTS

During 1980-1999, 1823 patients were incident. Three-hundred and three males and 191 females had CO, 744 males and 585 females had AO GHD. The incidence rate over time was stable for females with AO GHD and increasing for the other three subgroups. Average incidence rate for CO males, 2.58 (95% confidence interval (CI), 2.30-2.88), CO females, 1.70 (95% CI, 1.48-1.96), AO males, 1.90 (95% CI, 1.77-2.04), and AO females, 1.42 (95% CI, 1.31-1.54) all per 100 000. The incidence rate was significantly higher in males compared to females in the CO GHD group (P < 0.001) and in the AO GHD group in the age ranges of 45-64 and 65+years (P < 0.001). There was no significant difference in the 18-44 years age group.

CONCLUSIONS

In conclusion, we have identified the incidence rates of GHD in a nationwide study of Denmark. In this population-based study, we have identified in CO GHD and in the two oldest age groups of AO GHD, a statistically significant higher incidence rate in males when compared with females.

Morbidity in Klinefelter syndrome: a Danish register study based on hospital discharge diagnoses

BACKGROUND

Klinefelter syndrome (KS) is the most prevalent sex chromosome disorder in man; it affects approximately one in 660 men and is a common cause of hypogonadism and infertility. Our current knowledge of morbidity in KS is based on observational studies and case reports and therefore is limited.

DESIGN

We used Danish registers to obtain dates of hospital admissions and discharge diagnoses in a cohort of all males diagnosed with KS in Denmark and a randomly selected, age-matched control group. Our cohort consisted of 832 KS subjects and 4033 control subjects, contributing with a total of approximately 100,000 person years. We used stratified Cox regression analysis on main groups of diagnoses. Where significant results were found, subsequent analyses were performed on subgroups of diagnoses.

RESULTS

We found a significantly increased risk of being hospitalized among the KS subjects [hazard ratio (HR), 1.69; 95% confidence interval, 1.54-1.86]. The increased admission risk was present in all but one of the main diagnosis groups, with the highest HRs for congenital malformations (HR, 10.7), psychiatric disorders (HR, 3.7), and endocrine and metabolic disorders (HR, 3.2). We compared hospitalization rates before and after the diagnosis of KS and found that the increased rate was present even before the diagnosis of KS.

CONCLUSIONS

Males suffering from KS experienced an increased hospitalization rate from a variety of disorders. Some are likely to be caused by hypogonadism, and some may be linked to the syndrome per se, whereas others are not readily explained. However, other factors, e.g. socioeconomic, may be involved.

Adenosine concentration in the porcine coronary artery wall and A2A receptor involvement in hypoxia-induced vasodilatation

We tested whether hypoxia-induced coronary artery dilatation could be mediated by an increase in adenosine concentration within the coronary artery wall or by an increase in adenosine sensitivity. Porcine left anterior descendent coronary arteries, precontracted with prostaglandin F(2alpha) (10(-5) M), were mounted in a pressure myograph and microdialysis catheters were inserted into the tunica media. Dialysate adenosine concentrations were analysed by HPLC. Glucose, lactate and pyruvate were measured by an automated spectrophotometric kinetic enzymatic analyser. The exchange fraction of [(14)C]adenosine over the microdialysis membrane increased from 0.32 +/- 0.02 to 0.46 +/- 0.02 (n = 4, P < 0.01) during the study period. At baseline, interstitial adenosine was in the region of 10 nM which is significantly less than previously found myocardial concentrations. Hypoxia (P(O(2)) 30 mmHg for 60 min, n = 5) increased coronary diameters by 20.0 +/- 2.6% (versus continuous oxygenation -3.1 +/- 2.4%, n = 6, P < 0.001) but interstitial adenosine concentration fell. Blockade of adenosine deaminase (with erythro-9-(2-hydroxy-3-nonyl-)-adenine, 5 microM), adenosine kinase (with iodotubericidine, 10 microM) and adenosine transport (with n-nitrobenzylthioinosine, 1 microM) increased interstitial adenosine but the increase was unrelated to hypoxia or diameter. A coronary dilatation similar to that during hypoxia could be obtained with 30 microM of adenosine in the organ bath and the resulting interstitial adenosine concentrations (n = 5) were 20 times higher than the adenosine concentration measured during hypoxia. Adenosine concentration-response experiments showed vasodilatation to be more pronounced during hypoxia (n = 9) than during normoxia (n = 9, P < 0.001) and the A(2A) receptor antagonist ZM241385 (20 nM, n = 5), attenuated hypoxia-induced vasodilatation while the selective A(2B) receptor antagonist MRS1754 (20 nM, n = 4), had no effect. The lactate/pyruvate ratio was significantly increased in hypoxic arteries but did not correlate with adenosine concentration. We conclude that hypoxia-induced coronary artery dilatation is not mediated by increased adenosine produced within the artery wall but might be facilitated by increased adenosine sensitivity at the A(2A) receptor level.

Myocardial injury with biomarker elevation in diabetic ketoacidosis

We report of two patients with severe ketoacidosis, minute elevations of myocardial biomarkers (troponin T and CK-MB) and initial ECG changes compatible with myocardial infarction (MI). All successive investigations, including coronary arteriography, were normal, and the patients recovered fully without further evidence of ischemic heart disease. We suggest that acidosis and very high levels of free fatty acids could cause membrane instability and biomarker leakage. Regardless of the pathogenesis, these two case stories suggest that nonspecific myocardial injury may occur in severe diabetic ketoacidosis and that the presence of minute biomarker elevation and ECG changes does not necessarily signify MI.

Fulminant lactic acidosis in two patients with Type 2 diabetes treated with metformin

Lactic acidosis is a known adverse risk of metformin treatment. We report two cases in whom fulminant lactic acidosis developed during treatment. There were no contraindications to metformin treatment and both were admitted with abdominal discomfort for some days, causing dehydration. Both patients had renal failure on admission, developed multiple organ failure and both suffered a massive stroke. One patient died and the other survived but is severely disabled. We suggest, in both cases, that acute renal failure developed as a result of dehydration, causing metformin accumulation and lactic acidosis. We recommend that all patients on metformin should consider discontinuation of metformin treatment in the event of a severe medical condition causing dehydration.

Insulin increases glycolysis without further vasodilation in porcine coronary arteries exposed to hypoxia

In acute ischaemia, glucose-insulin-potassium administration reduces mortality and beta-adrenoceptor antagonists have favourable effects on the outcome of ischaemic heart disease. The present study was designed to investigate whether insulin (1.4x10(-7) M) and the beta-adrenoceptor antagonist, propranolol (10(-5) M), increase hypoxic vasodilation in correspondence with changes in glycolysis. Porcine coronary arteries, precontracted with 10(-5) M prostaglandin F(2alpha), were mounted in a pressure myograph and a microdialysis catheter was inserted in the tunica media. Hypoxic vasodilation, interstitial lactate/pyruvate ratio and interstitial glucose were measured at low (2 mM) and high (20 mM) glucose concentrations. Hypoxia (60 min) caused vasodilation and doubled the lactate/pyruvate ratio. Treatment with insulin quadrupled the lactate/pyruvate ratio during hypoxia, but did not change hypoxic vasodilation. Propranolol blocked isoprenaline-evoked vasodilation, but hypoxic increases in lactate/pyruvate ratio and vasodilation did not change. The combination of insulin and propranolol did not cause further changes compared with each drug added alone, although the combination increased vasoconstriction during reoxygenation. Interstitial glucose fell during hypoxia at an organ bath glucose concentration of 2 mM, and rose at a glucose concentration of 20 mM. Addition of insulin and propranolol alone or in combination had no effect on interstitial glucose concentration. Accordingly, arteries were found to contain only minute amounts of the glucose transporter isoform GLUT4. Our findings suggest that insulin increases arterial glycolysis, but treatment with insulin, propranolol, or both, is not associated with enhanced coronary vasodilation during hypoxia.

Increased mortality in Klinefelter syndrome

Klinefelter syndrome (KS) is the most prevalent sex chromosome disorder in man and is a common cause of hypogonadism. To describe mortality in KS, we conducted an epidemiological study, using Danish registers covering the entire nation. We constructed a cohort of 781 Danish boys and men diagnosed with KS (from the Danish Cytogenetic Central Register) and a control group of 3803 men, matched by month and year of birth. Vital status was obtained from the Centralized Civil Register, and causes of death were obtained from the National Register of Causes of Death. We used Cox regression with stratification on groups of diagnoses according to International Classification of Diseases, 10th version. Where significant results were found, subsequent analyses were performed on subdivisions of diagnoses. We found that Klinefelter syndrome was associated with a significant increase in mortality risk of 40% (hazard ratio, 1.40; 95% confidence interval, 1.13-1.74), corresponding to a significantly reduced median survival of 2.1 yr. The increased mortality was mainly due to increased mortality from infectious, neurological, circulatory, pulmonary, and urinary tract diseases. Whether this increase is caused by the syndrome per se (i.e. hypogonadism) or other factors, e.g. socioeconomic, are involved is presently unknown.

Additive effects of cortisol and growth hormone on regional and systemic lipolysis in humans

Growth hormone (GH) and cortisol are important to ensure energy supplies during fasting and stress. In vitro experiments have raised the question whether GH and cortisol mutually potentiate lipolysis. In the present study, combined in vivo effects of GH and cortisol on adipose and muscle tissue were explored. Seven lean males were examined four times over 510 min. Microdialysis catheters were inserted in the vastus lateralis muscle and in the subcutaneous adipose tissue of the thigh and abdomen. A pancreatic-pituitary clamp was maintained with somatostatin infusion and replacement of GH, insulin, and glucagon at baseline levels. At t = 150 min, administration was performed of NaCl (I), a 2 microg.kg(-1).min(-1) hydrocortisone infusion (II), a 200-microg bolus of GH (III), or a combination of II and III (IV). Systemic free fatty acid (FFA) turnover was estimated by [9,10-3H]palmitate appearance. Circulating levels of glucose, insulin, and glucagon were comparable in I-IV. GH levels were similar in I and II (0.50 +/- 0.08 microg/l, mean +/- SE). Peak levels during III and IV were approximately 9 microg/l. Cortisol levels rose to approximately 900 nmol/l in II and IV. Systemic (i.e., palmitate fluxes, s-FFA, s-glycerol) and regional (interstitial adipose tissue and skeletal muscle) markers of lipolysis increased in response to both II and III. In IV, they were higher and equal to the isolated additive effects of the two hormones. In conclusion, we find that GH and cortisol stimulate systemic and regional lipolysis independently and in an additive manner when coadministered. On the basis of previous studies, we speculate that the mode of action is mediated though different pathways.

Effects of cortisol on lipolysis and regional interstitial glycerol levels in humans

Cortisol's effects on lipid metabolism are controversial and may involve stimulation of both lipolysis and lipogenesis. This study was undertaken to define the role of physiological hypercortisolemia on systemic and regional lipolysis in humans. We investigated seven healthy young male volunteers after an overnight fast on two occasions by means of microdialysis and palmitate turnover in a placebo-controlled manner with a pancreatic pituitary clamp involving inhibition with somatostatin and substitution of growth hormone, glucagon, and insulin at basal levels. Hydrocortisone infusion increased circulating concentrations of cortisol (888 +/- 12 vs. 245 +/- 7 nmol/l). Interstitial glycerol concentrations rose in parallel in abdominal (327 +/- 35 vs. 156 +/- 30 micromol/l; P = 0.05) and femoral (178 +/- 28 vs. 91 +/- 22 micromol/l; P = 0.02) adipose tissue. Systemic [(3)H]palmitate turnover increased (165 +/- 17 vs. 92 +/- 24 micromol/min; P = 0.01). Levels of insulin, glucagon, and growth hormone were comparable. In conclusion, the present study unmistakably shows that cortisol in physiological concentrations is a potent stimulus of lipolysis and that this effect prevails equally in both femoral and abdominal adipose tissue.

Medical problems of adult Turner's syndrome

Several issues should be addressed when managing women with Turner's syndrome. Female sex hormone substitution should be offered to help prevent the increased morbidity seen in Turner's women, which consists of an increased risk of fractures and osteoporosis, and a clustering of diseases such as ischaemic heart disease, hypertension, stroke and type 2 diabetes, the latter entities being part of the insulin resistance syndrome. Furthermore, hypothyroidism is often seen, and the risk of type 1 diabetes may also be increased. Congenital malformations of the heart are frequently seen in Turner's syndrome, possibly increasing the risk of dissecting aorta aneurysm. Liver enzymes are often elevated and there may be an increased risk of liver cirrhosis. Mortality seems to be increased in Turner's syndrome, women with the "pure" 45,X karyotype being the most severely affected. In clinical practice, careful monitoring of glucose and bone metabolism, weight, thyroid function and blood pressure should be carried out. A cardiovascular risk profile should be determined and the patient informed of the risks and benefits of sex hormone replacement therapy. 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's syndrome. Since general physicians only encounter these patients infrequently, it is recommended that the care and treatment of Turner's syndrome be centralized.

Measurement of interstitial lactate during hypoxia-induced dilatation in isolated pressurised porcine coronary arteries

Lactate is formed in the coronary arterial wall and in the myocardium as a consequence of ischaemia and infarction. We combined direct measurement of coronary artery diameter and interstitial arterial wall lactate concentration ex vivo in order to ascertain the possible role of lactate in hypoxia-induced vasodilatation. The wall of porcine coronary arteries, precontracted during an intraluminal pressure of 40 mmHg by addition of prostaglandin F2alpha, was cannulated using a microdialysis catheter, and exposed to hypoxia for 60 min, followed by 45 min of reoxygenation. The exchange fraction of [14C]lactate over the microdialysis membrane increased from 0.38 +/- 0.04 to 0.52 +/- 0.05 (P < 0.001) during the study period. Coronary artery diameter increased by 15.5 +/- 2.0 % (n = 20) during hypoxia (P < 0.001, compared to normoxic controls) and interstitial lactate concentration rose from 1.07 +/- 0.21 to 2.50 +/- 0.40 mmol x l(-1) during hypoxia (P < 0.01) and was unchanged in controls. The increase in coronary artery diameter correlated with the increase in interstitial lactate concentration in the period between 30 and 60 min of hypoxia (r = 0.62; P = 0.02). Dichloroacetate (10(-5) M), an agent that reduces lactate generation by activating pyruvate dehydrogenase, abolished hypoxia-induced lactate production, but caused a further increase in coronary arterial diameter (30.2 +/- 4.4 %, n = 9; P < 0.001 vs. hypoxia and no dichloroacetate). Under control conditions, the addition of L-lactate (10(-3)-10(-2) M) increased dose-dependently coronary arterial diameter by 22.0 +/- 4.2 % (n = 5) and interstitial lactate concentration from 0.52 +/- 0.04 to 5.70 +/- 0.66 mmol x l(-1) (P < 0.001). There was a correlation between the increase in coronary artery diameter and interstitial lactate concentration (r = 0.60; P = 0.02). The present observations represent the first direct measurements of metabolites by microdialysis in a blood vessel wall. The lactate concentration may affect, but is not essential for, hypoxia-induced vasodilatation in porcine coronary arteries.

Evidence of a normal mean telomere fragment length in patients with Ullrich-Turner syndrome

Clinical and epidemiological studies suggest that premature ageing and increased morbidity and mortality is present in Ullrich-Turner syndrome. We studied telomere restriction fragment length (TRFL) in 30 women with Ullrich-Turner syndrome and 30 age-matched control women. All Turner women had the 45,X karyotype verified by karyotyping. We found no difference in the mean TRFL in the young age group (TS: 7011+/-521 vs C: 7285+/-917 bp, P = 0.3), or in the older age group (TS: 7357+/-573 vs C: 7221+/-621 bp, P = 0.6). In conclusion, our data suggest that Ullrich-Turner syndrome is not associated with excessive telomere loss, at least when studied in peripheral blood leucocytes, and thus quite different from other premature ageing syndromes.

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.

Recommendations for the diagnosis and management of Turner syndrome

Comprehensive recommendations on the diagnosis of Turner syndrome (TS) and the care of affected individuals were published in 1994. In the light of recent advances in diagnosis and treatment of TS, an international multidisciplinary workshop was convened in March 2000, in Naples, Italy, in conjunction with the Fifth International Symposium on Turner Syndrome to update these recommendations. The present paper details the outcome from this workshop. The genetics and diagnosis of the syndrome are described, and practical treatment guidelines are presented.

Physiological levels of glucagon do not influence lipolysis in abdominal adipose tissue as assessed by microdialysis

To determine whether glucagon stimulates lipolysis in adipose tissue, seven healthy young male volunteers were studied, with indwelling microdialysis catheters placed sc in abdominal adipose tissue. Subjects were studied three times: 1) during euglucagonemia (EG; glucagon infusion rate, 0.5 ng/kg.min); 2) during hyperglucagonemia (HG; (glucagon infusion rate, 1.5 ng/kg.min); and 3) during EG and a concomitant glucose infusion mimicking the glucose profile from the day of HG (EG+G). Somatostatin (450 microg/h) was infused to suppress hormonal secretion, and replacement doses of insulin and GH were administered. Sampling was done every 30 min for 420 min. Baseline circulating values of insulin, C-peptide, glucagon, GH, glycerol, and free fatty acids were comparable in all three conditions. During EG and EG+G, plasma glucagon was maintained at fasting level (20-40 ng/L); whereas, during HG, it increased (110-130 ng/L). Interstitial concentrations of glycerol were similar in the three conditions [30,870 +/- 5,946 (EG) vs. 31,074 +/- 7,092 (HG) vs. 29,451 +/- 6,217 (EG+G) micromol/L.120 min, P = 0.98]. Plasma glycerol (ANOVA, P = 0.5) and free fatty acids (ANOVA, P = 0.3) were comparable during the different glucagon challenges. We conclude that HG per se does not increase interstitial glycerol (and thus lipolysis) in abdominal sc adipose tissue; nor does modest hyperglycemia, during basal insulinemia and glucagonemia, influence indices of abdominal sc lipolysis.