Effect of discontinuation of long-term growth hormone treatment on carbohydrate metabolism and risk factors for cardiovascular disease in girls with Turner syndrome

Clinical practice guidelines for the care of girls and women with Turner syndrome

Turner syndrome (TS) affects 50 per 100 000 females. TS affects multiple organs through all stages of life, necessitating multidisciplinary care. This guideline extends previous ones and includes important new advances, within diagnostics and genetics, estrogen treatment, fertility, co-morbidities, and neurocognition and neuropsychology. Exploratory meetings were held in 2021 in Europe and United States culminating with a consensus meeting in Aarhus, Denmark in June 2023. Prior to this, eight groups addressed important areas in TS care: (1) diagnosis and genetics, (2) growth, (3) puberty and estrogen treatment, (4) cardiovascular health, (5) transition, (6) fertility assessment, monitoring, and counselling, (7) health surveillance for comorbidities throughout the lifespan, and (8) neurocognition and its implications for mental health and well-being. Each group produced proposals for the present guidelines, which were meticulously discussed by the entire group. Four pertinent questions were submitted for formal GRADE (Grading of Recommendations, Assessment, Development and Evaluation) evaluation with systematic review of the literature. The guidelines project was initiated by the European Society for Endocrinology and the Pediatric Endocrine Society, in collaboration with members from the European Society for Pediatric Endocrinology, the European Society of Human Reproduction and Embryology, the European Reference Network on Rare Endocrine Conditions, the Society for Endocrinology, and the European Society of Cardiology, Japanese Society for Pediatric Endocrinology, Australia and New Zealand Society for Pediatric Endocrinology and Diabetes, Latin American Society for Pediatric Endocrinology, Arab Society for Pediatric Endocrinology and Diabetes, and the Asia Pacific Pediatric Endocrine Society. Advocacy groups appointed representatives for pre-meeting discussions and the consensus meeting.

Components of the metabolic syndrome in girls with Turner syndrome treated with growth hormone in a long term prospective study

Background

Components of the metabolic syndrome are more common in patients with Turner syndrome (TS) than in the general population. Long-term growth hormone (GH) treatment also affects the parameters of carbohydrate metabolism. Therefore, all these factors should be monitored in girls with TS.

Objective

To assess the occurrence of metabolic syndrome components in TS girls before GH treatment and to monitor changes in metabolic parameters throughout GH therapy.

Patients and method

89 TS patients were enrolled in the study. Clinical and laboratory data after the 1st (V1), 3rd (V3), 5th (V5) and 10th (V10) year of GH therapy was available respectively in 60, 76, 50 and 22 patients. The patients' biochemical phenotypes were determined by glucose 0', 120', insulin 0', 120', HOMA-IR, Ins/Glu ratio, HDL-cholesterol and triglycerides (TG) concentration.

Results

Obesity was found during V0 in 7.9% of patients,V1 - 5%, V3 - 3.9%, V5 - 2%, V10 - 0%. No patient met diagnostic criteria for diabetes. A significant increase in the basal plasma glucose 0' was found in the first five years of therapy (pV0-V1 < 0.001; pV0-V3 = 0.006; pV0-V5 < 0.001). V10 glucose 120' values were significantly lower than at the onset of GH treatment (pV0-V10 = 0.046). The serum insulin 0' and 120' concentrations as well as insulin resistance increased during treatment. No statistically significant differences in serum TG and HDL-cholesterol levels during GH therapy were found.

Conclusion

The development of insulin resistance and carbohydrate metabolism impairment have the greatest manifestations during GH therapy in girls with TS. Monitoring the basic parameters of carbohydrate-lipid metabolism in girls with TS seems particularly important.

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

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

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.

Progression of Vasculopathy in Young Individuals with Turner Syndrome

Vasculopathy has been identified in young individuals with Turner syndrome (TS). No studies in young individuals with TS have investigated whether this vasculopathy progresses over time. The objective of this study is to describe the changes in vasculopathy over time in a cohort of young individuals with TS. Repeat ultrasound and SphygmoCor CPV® (AtCor Medical) measurements of carotid thickness and peripheral arterial stiffness were performed. Vascular measurements were compared at baseline and follow-up. Follow-up measurements were also compared to historical lean (L) and obese (O) age-, race-, and sex-matched non-TS controls. Thirty-five individuals with TS were studied at a mean age of 19.4 years (range, 13.9-27.5). Mean time to follow-up was 7.2 years (range, 7.1-7.8). Carotid intima media thickness increased by 0.03 ± 0.07 mm (p < 0.01) over time, but was less than L and O controls at follow-up. Pulse wave velocity carotid-femoral increased by 0.51 ± 0.86 m/s (p < 0.01) over time, but was similar to L and less than O controls at follow-up. Augmentation index (AIx) remained unchanged (p = 0.09) over time, but was significantly higher at follow-up than both control groups (p < 0.01 for both). There were no identified differences between 45,X and other TS genotypes. We demonstrate evidence of vascular thickening and stiffening over 7 years in a cohort of young individuals with TS, as well as a persistently increased augmentation index compared to L and O non-TS controls. It is unclear whether the increase in vascular structure and function are related to normal aging or if TS is a risk factor. Higher body mass index seems to be a risk factor. Early estrogen replacement and longer exposure to growth hormone therapy need to be further explored as potential protective factors.

The influence of growth hormone therapy on the cardiovascular system in Turner syndrome

Short stature, ovarian dysgenesis, infertility, and cardiovascular malformations are classic features in Turner syndrome (TS), but the phenotypical spectrum is wide. Through early diagnosis and appropriate treatment, TS patients have a chance to achieve satisfactory adult height and sexual development. The doses of recombinant growth hormone (rGH) used are usually higher than the substitution dose. The safety aspects of this therapy are very important, especially in terms of the cardiovascular system. The presented study aimed to analyze how the rGH therapy may influence the cardiovascular system in TS based on current literature data. We conducted a systematic search for studies related to TS, cardiovascular system, and rGH therapy. The results show that rGH seems to have a positive effect on lipid parameters, reducing the risk of ischemic disease. It is additionally optimized by estradiol therapy. Although rGH may increase insulin resistance, the metabolic derangement is rare, probably due to lower fat content and an increase in lean body mass. Several studies showed that rGH treatment could cause aorta widening or increase the aorta growth rate. IGF-1 can be independently associated with increased aortic diameters. The studies analyzing the impact of GH on blood pressure show conflicting data. The proper cardiovascular imaging before and during rGH treatment and detecting the known risk factors for aorta dissection in every individual is very important. The long-term effects of growth hormone treatment on the heart and arteries are still not available and clearly estimated and have to be monitored in the future.

Recognition and management of adults with Turner syndrome: From the transition of adolescence through the senior years

Turner syndrome is recognized now as a syndrome familiar not only to pediatricians and pediatric specialists, medical geneticists, adult endocrinologists, and cardiologists, but also increasingly to primary care providers, internal medicine specialists, obstetricians, and reproductive medicine specialists. In addition, the care of women with Turner syndrome may involve social services, and various educational and neuropsychologic therapies. This article focuses on the recognition and management of Turner syndrome from adolescents in transition, through adulthood, and into another transition as older women. It can be viewed as an interpretation of recent international guidelines, complementary to those recommendations, and in some instances, an update. An attempt was made to provide an international perspective. Finally, the women and families who live with Turner syndrome and who inspired several sections, are themselves part of the broad readership that may benefit from this review.

Cardiometabolic health in Turner syndrome

Individuals with Turner syndrome (TS) have a higher morbidity and mortality compared to the general population. Diabetes and cardiovascular disease are the major contributors to this burden. Precursors to diabetes and cardiovascular disease make up what is known as metabolic syndrome, including abdominal obesity, hypertension, dyslipidemia, and elevated fasting glucose. These features of poor cardiometabolic health are also prevalent among women with TS. Youth with TS also exhibit many of these features, indicating that the pathogenesis of these cardiometabolic conditions may begin early in life. The etiology of the increased risk of cardiometabolic conditions in TS is likely multifactorial, involving genetics, epigenetics, hypogonadism, medical comorbidities, medications, and lifestyle. Counseling for the increased risk of cardiometabolic diseases as well as efforts to prevent or lower this risk should be routinely provided in the care of all patients with TS. Clinical practice guidelines are now available to guide screening and treatment of cardiometabolic conditions in girls and women with TS.

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

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

Impact of discontinuation of growth hormone treatment on lipids and weight status in adolescents

BACKGROUND

While the main role of growth hormone (GH) replacement therapy in children is to promote linear growth, GH has also an effect on lipids and body composition. There is an ongoing discussion whether discontinuation of GH treatment is associated with deterioration of lipids.

METHODS

We analyzed weight status [as body mass index-standard deviation score (BMI-SDS)], insulin like growth factor (IGF)-1, triglycerides, total, low-density liporptoein (LDL)- and high-density lipoprotein (HDL)-cholesterol at the end of GH treatment and in mean 6 months later in 90 adolescents (53 with GH deficiency, 16 with Turner syndrome [TS] and 21 born small-for-gestational age [SGA]).

RESULTS

After stopping GH treatment, total cholesterol (+10±24 mg/dL vs. -4±13 mg/dL) and LDL-cholesterol (+15±20 mg/dL vs. -6±12 mg/dL) increased significantly higher in severe (defined by GH peak in stimulation test <3 ng/mL) compared to moderate GHD. In patients with TS, total cholesterol (+19±9 mg/dL), LDL-cholesterol (+9±12 mg/dL) and HDL-cholesterol (+4.3±3.5 mg/dL) increased significantly. In adolescents born SGA, triglycerides increased (+34±51 mg/dL) and HDL-cholesterol decreased significantly (-3.8±7.1 mg/dL). In multiple linear regression analyses, changes of total and LDL-cholesterol were significantly negatively related to peak GH in stimulation tests, but not to gender, age at GH start, duration of GH treatment, observation time, changes of BMI-SDS or IGF-1 after the end of GH treatment. The BMI-SDS did not change after the end of GH treatment.

CONCLUSIONS

Discontinuation of GH treatment leads to a deterioration of lipids in TS, SGA and severe but not moderate GHD.

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

BACKGROUND

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

METHODS AND RESULTS

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

CONCLUSION

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

Update on Turner and Noonan syndromes

Turner syndrome (TS) and Noonan syndrome (NS) have short stature as a constant feature; however, both conditions can present clinicians with a challenging array of genetic, cardiovascular, developmental, and psychosocial issues. In recent years, important advances have been achieved in each of these areas. This article reviews these two syndromes and provides updates on recent developments in diagnostic evaluation, growth and development, psychological issues, and treatment options for patients with TS and NS.

Favorable impact of growth hormone treatment on cholesterol levels in turner syndrome

Background: Patients with Turner syndrome (TS) are prone to having metabolic abnormalities, such as obesity, dyslipidemia, hypertension, hyperinsulinemia and type 2 diabetes mellitus, resulting in increased risks of developing atherosclerotic diseases. Objective: To determine the effect of growth hormone (GH) therapy on serum cholesterol levels in prepubertal girls with TS enrolled in the Turner syndrome Research Collaboration (TRC) in Japan. Patients and methods: Eighty-one girls with TS were enrolled in the TRC, and their total cholesterol (TC) levels before GH therapy were compared with reported levels of healthy school-aged Japanese girls. TC levels after 1, 2 and 3 yr of GH treatment were available for 28 of the 81 patients with TS. GH was administered by daily subcutaneous injections, 6 or 7 times/wk, with a weekly dose of 0.35 mg/kg body weight. Results: Baseline TC levels revealed an age-related increase in TS that was in contrast to healthy girls showing unchanged levels. During GH therapy, TC decreased significantly after 1 yr of GH treatment and remained low thereafter. Conclusions: Girls with untreated TS showed an age-related increase in TC that was a striking contrast to healthy girls, who showed unchanged levels. GH therapy in girls with TS brought about a favorable change in TC that indicates the beneficial impact of GH on atherogenic risk.

Turner syndrome and metabolic derangements: another example of fetal programming

BACKGROUND AND AIM

Turner syndrome (TS) patients have an increased risk of weight gain and metabolic syndrome. To date, it is unknown what factors are involved in this metabolic process, even though it is recognized that TS patients are frequently born small-for-gestational age. The aim of this study was to evaluate the correlation between lipid and glucose profiles with being overweight and birth weight and length in TS patients.

STUDY DESIGN

This was a cross-sectional study.

SUBJECTS AND OUTCOME MEASURES

Serum glucose, insulin (HOMA-IR), total cholesterol, and triglycerides were measured in 64 patients with TS. Data regarding birth weight and length and current body mass index (BMI) were also evaluated.

RESULTS

Total cholesterol showed a significant negative correlation with birth weight and a positive correlation with BMI; triglycerides showed significant negative correlation with birth weight and length and a positive correlation with BMI; and HOMA-IR showed a significant negative correlation with birth weight and length. Low birth weight and a high BMI were predictive for 28% of total cholesterol and triglycerides; and low birth weight for 22% of HOMA-IR.

CONCLUSIONS

Lipid profile was correlated with a high current BMI and low birth weight and length in TS patients and glucose profile only with low birth weight. Thus far, growth retardation may play a role in metabolic derangements in this group of patients, being considered another example of fetal programming.

The benefits of growth hormone therapy in patients with Turner syndrome, Noonan syndrome and children born small for gestational age

This review will summarize the effects of growth hormone (GH) on height, body composition, bone and psychosocial parameters in children with Turner syndrome or Noonan syndrome and those born small for gestational age. The safety of GH treatment in children with these diagnoses is also reported. Despite the reported efficacy and safety of GH in these indications, however, not all children achieve their target height potential, due in some part to poor adherence to GH therapy regimens; indeed up to 50% of children are less than fully compliant with treatment. With this in mind the present and future administration of GH therapy is discussed with respect to advances being made in the presentation of GH for injection and advances in GH injection devices. It is hoped that such progress, aimed at making the administration of GH easier and less painful for the patient will improve treatment adherence and outcome benefits.

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

BACKGROUND

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Free dissociable insulin-like growth factor I (IGF-I), total IGF-I and their binding proteins in girls with Turner syndrome during long-term growth hormone treatment

OBJECTIVE

To investigate the effect of GH treatment on free IGF-I levels in girls with Turner syndrome (TS) and to verify relationships between free IGF-I levels and total IGF-I, IGFBP-1, 2 and 3. Additionally, to analyse whether free IGF-I, total IGF-I, IGFBP-3 or its ratio were related to IGF-I bioactivity outcome parameters.

DESIGN

Sixty-five girls with TS were randomly assigned to three different GH-dosage groups (1.3, 2.0 and 2.7 mg/m2/day). Mean duration of GH therapy was mean (SD) 8.7(2.0) years. Free IGF-I, total IGF-I and IGFBP-1, -2, -3 were determined at baseline, first, second, third and fifth year of GH therapy, before the start of oestrogen therapy, during the final year of GH treatment, 6 months after GH and 4.8(2.0) years after GH discontinuation.

MAIN OUTCOME

During GH treatment, mean free IGF-I levels stayed < +2 standard deviation score (sds), whereas mean total IGF-I and IGF-I/IGFBP-3 ratio were > +2 sds. There were no differences in free IGF-I levels between the three GH groups, whereas total IGF-I and ratio levels were significantly higher in the highest GH group. The following variables contributed significantly to predicting the square root of free IGF-I levels: age, GH dose, oestrogen dose, IGFBP-1, IGFBP-3, body mass index and total IGF-I or IGF-I/IGFBP-3 ratio. However, the explaining variance did not exceed 55%. Several IGF-I bioactivity outcome parameters positively correlated with total IGF-I and IGF-I/IGFBP-3 ratio, whereas free IGF-I did not.

CONCLUSIONS

During long-term GH therapy in girls with TS, mean free IGF-I levels stayed within the normal range, whereas mean total IGF-I and IGF-I/IGFBP-3 ratio exceeded the upper normal range. Although total IGF-I and the IGF-I/IGFBP-3 ratio did not accurately represent free IGF-I levels, they seemed to better represent the IGF-I bioactivity than the measured free IGF-I.

Turner Syndrome, Insulin Sensitivity and Growth Hormone Treatment

Mild insulin resistance appears to be an early metabolic defect in girls with Turner syndrome (TS). Impaired glucose tolerance has been reported in 10-34% of patients with TS, and type 2 diabetes mellitus is 2-4 times more common and occurs at a younger age in girls with TS than in the general population. In a mixed longitudinal and cross-sectional study, we analysed carbohydrate tolerance and insulin sensitivity in 46 children and adolescents with TS who reached their final height after long-term treatment (mean 6.3 +/- 2.5 years) with growth hormone (GH: 0.33 mg/kg/week [0.05 mg/kg/day]), and in 36 of these patients who were followed-up after the cessation of GH therapy (mean follow-up, 2.6 +/- 2.5 years; range, 1-9.5 years). Patients with TS were compared with an age-matched female control group. Insulin sensitivity appeared to be lower in patients with TS than in controls, even before the start of GH therapy. As in controls, insulin sensitivity decreased with age in patients with TS, and levels were lower in those aged >12 years than in those aged <12 years. GH therapy resulted in good catch-up growth in patients with TS, with final height significantly higher than projected height evaluated before the initiation of GH therapy. Insulin sensitivity increased after 7-8 years of therapy and, on the cessation of GH therapy, returned to pre-treatment levels. The increase in insulin sensitivity seen on the cessation of GH therapy appeared to be influenced negatively by body mass index and triglyceride levels, and correlated positively with the number of years since cessation of GH therapy. As in the general population, excess weight and an abnormal lipid profile, in particular excess triglyceride levels, worsened insulin sensitivity. In conclusion, our study confirms that GH therapy reduces insulin sensitivity, but at its cessation there is a return to pre-therapy values. We therefore report a progressive improvement in carbohydrate tolerance and insulin function in patients with TS, despite an increase in age.

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

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

CONCLUSION

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