CHILDHOOD THYROTOXICOSIS: A LONG-TERM PERSPECTIVE

Thyroid function and long-term outcomes of children born to mothers with Graves' disease: A 20-year review

AIM

Thyroid dysfunction in infants born to mothers with Graves' disease (GD) is influenced by maternal factors including thyroid status, thyroid-stimulating hormone (TSH) receptor antibody (TRAb) concentration and antithyroid drug use. Thyroid dysfunction during early life could affect growth and development later in life. The aim of this study is to evaluate thyroid function tests (TFTs), and long-term growth and development of children born to mothers with GD.

METHODS

A retrospective chart review of children born to mothers with GD at the Faculty of Medicine Ramathibodi Hospital, Mahidol University, between January 2000 and December 2019 was performed. Clinical data including age of children at enrolment, sex, gestational age, birthweight, maternal thyroid status, maternal TRAb level, maternal GD treatment during pregnancy, neonatal TSH screening and TFT results, and growth and development outcomes of children were collected.

RESULTS

There were 262 children (148 males) enrolled. Twelve (4%) infants had neonatal GD. Five (2%) infants had hypothyroidism requiring levothyroxine treatment: four had secondary hypothyroidism and one patient had congenital primary hypothyroidism. Seven (3%) infants had transient TSH elevation, which fell to normal by 2 weeks of age. The remaining 238 children had normal TFT results. Three out of 12 children with neonatal GD had either delayed growth or development.

CONCLUSIONS

A number of infants born to mothers with GD had abnormal TFTs requiring specific management, and some of them had abnormal growth and development. Careful evaluation of TFTs and long-term follow-up are mandatory for those children.

Approach to the Patient: Management and the Long-term Consequences of Graves' Disease in Children

In children, Graves' disease (GD) is the most common cause of hyperthyroidism. Most pediatric patients with GD will not go into lasting remission, even following many years of antidrug therapy. Thus, most pediatric patients will require radioactive iodine (RAI) or surgery. When antithyroid drugs are used, methimazole is the drug of choice. When methimazole is used in children, up to 20% will have minor adverse reactions and serious adverse events occur in up to 1%. RAI is an effective form of therapy when the thyroid size is less than 80 g. Because of concerns of whole-body radiation exposure, it is recommended that RAI be avoided in children under 5 years of age, and dosages less than 10 mCi be used between 5 and 10 years of age. Surgery is an effective treatment in children if performed by a high-volume thyroid surgeon. Because of the scarcity of high-volume pediatric thyroid surgeons, a multidisciplinary approach using pediatric surgeons and endocrine surgeons can be considered. Whereas there is a trend toward long-term antithyroid drug therapy in adults, for several reasons, this approach may not be practical for children. Determining the optimal treatment for the pediatric patient with GD, requires consideration of the risks and benefits relating to age and likelihood of remission.

Evaluating thyroid function in pregnant women

Thyroid hormones are primarily responsible for regulating the basal metabolic rate but also make important contributions to reproductive function and fetal development. Both hyper- and hypothyroidism in pregnancy have been associated with increased risks of complications that include preeclampsia and low birth weight, among others. Furthermore, thyroid hormone deficiency in the developing fetus results in neurodevelopmental delay. As the fetus is exclusively reliant on maternal thyroid hormone for most of the first trimester and requires continued maternal supply until birth, identifying maternal thyroid dysfunction is critically important. However, evaluating thyroid function in pregnancy is challenging because of the many physiological changes that affect concentrations of thyroid-related analytes. Increasing plasma human chorionic gonadotropin (hCG) concentrations in the second half of the first trimester elicit a corresponding transient decrease in thyroid-stimulating hormone (TSH), and continually increasing estradiol concentrations throughout pregnancy cause substantial increases in thyroxine-binding globulin (TBG) and total thyroxine (T4) relative to the nonpregnant state. Lastly, free T4 concentrations gradually decrease with increasing gestational age. For these reasons, it is essential to interpret thyroid function test results in the context of trimester-specific reference intervals to avoid misclassification of thyroid status. This review summarizes the effects of thyroid dysfunction prior to conception and during pregnancy and describes considerations for the laboratory assessment of thyroid function in pregnant women.

Growing up different in Neolithic China: A contextualised case study and differential diagnosis of a young adult with skeletal dysplasia

This paper presents a case study of a young adult from the late Neolithic Yangshao cultural period site (∼3300-2900 years BC) of Guanjia () located in Henan Province on the Central Plains of China, who has evidence for skeletal dysplasia characterised by proportional stunting of the long bones and a small axial skeleton, generalised osteopenia, and non-fusion of epiphyses. We provide a detailed differential diagnosis of skeletal dysplasia with paediatric onset and conclude that this is likely a form of hypopituitarism or hypothyroidism, an extremely rare finding within the archaeological context. This paper highlights the issues of distinguishing the forms of proportional dwarfism in palaeopathology because of the considerable variation in manifestation of these conditions. Finally, we assess whether there were any health and social implications for this person and community through the consideration of a bioarchaeology of care approach across the lifecourse, burial context, and information on social perceptions of 'difference' in the community. ：： （3300～2900）。，，，，。，，。。，。，、、""，。.

The impact of thyroid diseases starting from birth on reproductive function

The aim of this review is to provide relevant information regarding the impact of thyroid disease, starting from birth and mainly concerning hyperthyroidism and hypothyroidism, on reproduction. Hyperthyroidism occurs much less commonly in children than hypothyroidism, with Graves' disease (GD) being the most common cause of thyrotoxicosis in children. Children born with neonatal GD have no defects in the reproductive system that could be related to hyperthyroidism. Current treatment options include antithyroid drugs (ATD), surgery, and radioactive iodine (RAI). In males, normal thyroid function seems important, at least in some parameters, for maintenance of semen quality via genomic or non-genomic mechanisms, either by locally acting on Sertoli cells, Leydig cells, or germ cells, or by affecting crosstalk between the HPT axis and the HPG axis. Sexual behavior may also be affected in thyroxic men, although many of these patients may have normal free testosterone levels. In women, menstrual irregularities are the most common reproduction-related symptoms in thyrotoxicosis, while this disorder is also associated with reduced fertility, although most women remain ovulatory. An increase in sex hormone-binding globulin (SHBG) and androgens, thyroid autoimmunity, and an impact on uterine oxidative stress are the main pathophysiological mechanisms which may influence female fertility. Thyroid hormones are responsible for normal growth and development during pre- and postnatal life, congenital hypothyroidism (CH) being the most common cause of neonatal thyroid disorders, affecting about one newborn infant in 3500. The reproductive tract appears to develop normally in cretins. Today, CH-screening programs allow for early identification and treatment, and, as a result, affected children now achieve normal or near-normal development. Hypothyroidism in males is associated with decreased libido or impotence. Although little is currently known about the effects of hypothyroidism on spermatogenesis and fertility, it has been established that sperm morphology and motility are mainly affected. In women of reproductive age, hypothyroidism results in changes in cycle length and amount of bleeding. Moreover, a negative effect on fertility and higher miscarriage rates has also been described.

Does transient hypothyroxinemia influence metabolic bone disease of prematurity?

OBJECTIVE

To investigate the relationship between Metabolic Bone Disease (MBD) and Transient Hypothyroxinemia of Prematurity (THOP).

METHOD

One hundred twenty-four infants, born in Marmara University Hospital with a gestational age ≤34 weeks, were enrolled. Clinical features were recorded. Serum TSH, free T4, total T4, calcium, phosphorus and total Alkaline Phosphatase (ALP) levels were determined in the first and third postnatal weeks. MBD was defined as a phosphorus level <4.5 mg/dl and/or ALP >900 IU/l. THOP was defined as a serum free and/or total thyroxine level lower than -1 SD for gestational age at the 7th postnatal day.

RESULT

THOP was diagnosed in nineteen (15.3%) patients. MBD was diagnosed in 52 (41.9%) at the 3rd month. Low birth weight, low gestational age and prolonged parenteral nutrition were associated with MBD. Multivariate analysis documented a significant relationship solely between MBD and gestational age.

CONCLUSION

The risk of MBD does not increase significantly in babies with THOP.

Clinical experience with radioactive iodine in the treatment of childhood and adolescent Graves' disease

BACKGROUND/AIMS

Treatments for Graves' disease (GD) in children and adolescents include oral antithyroid drugs (ATDs), near total thyroidectomy, and radioactive iodine (RAI). ATDs remain the preferred choice in this age group, but because persistent remission occurs in 30% of cases, RAI is becoming a common option for definitive therapy.

METHODS

We performed a review of 65 medical records of GD patients under age 19 years who were followed between 1985 and 2005.

RESULTS

The prevalence of GD was higher in females (3:1) and during puberty (for both genders). If no remission was detected during ATD treatment, RAI was indicated when the following criteria were present: non-compliance, relapse, or side effects that were related to ATDs, large goiter, and long-term use of ATDs. The majority of patients developed hypothyroidism within 6 months after RAI. A progressive higher dose regimen was implemented in the last 10 years of the study period. A second RAI dose was necessary in eight cases. During the follow-up period, three pregnancies occurred. One patient with a thyroid nodule and benign cytology was detected.

CONCLUSIONS

RAI therapy is effective and safe in the treatment of GD in children and adolescents.

Female reproduction physiology adversely manipulated by thyroid disorders: a review of literature

Proper thyroid function is vital to have a healthy reproduction system. Female sex hormones are altered due to hypothyroidism and hyperthyroidism. Female reproduction system is negatively manipulated by both hyperthyroidism and hypothyroidism and menstrual disorders are the ultimate consequences. Hypomenorrhea, polymenorrhea and oligomenorrhea are the clinical manifestation associated with hyperthyroidism and hypothyroidism, respectively. The female infertility is also adversely affected by thyrotoxicosis and myxedema, the clinical presentation of hyper and hypothyroidism. The simultaneous existence of autoimmunity which is present among some portion of pregnant women may aggravate the clinical manifestation of thyroid disorders in female reproductive physiology. Abortion, premature infants, low birth infant, are among clinical presentation of overt hypothyroidism. Auto antibody against thyroid stimulating hormone receptor and eventual hyperthyroidism considered as risk factors which require extra attention while the thyroid disorder is clinically managed during pregnancy to prevent the fetus from abnormal metabolism. The aim of this review is to elaborate the adverse role of hyperthyroidism and hypothyroidism in female reproduction physiology.

Prediction of post-treatment hypothyroidism using changes in thyroid volume after radioactive iodine therapy in adolescent patients with Graves' disease

BACKGROUND

The goal of iodine-131 therapy for pediatric Graves' disease is to induce hypothyroidism. However, changes in post-treatment thyroid volume have not been investigated in pediatric and/or adolescent patients.

OBJECTIVE

The aim of this retrospective study was to examine whether changes in thyroid volume predict post-treatment hypothyroidism in adolescent Graves' disease patients.

PATIENTS AND METHODS

We used ultrasonography to examine changes in thyroid volume, and also assessed thyroid functions, at 0, 1, 3, 5, 8 and 12 months after iodine-131 treatment in 49 adolescents ranging in age from 12 to 19 years retrospectively. Based on thyroid function outcome at 12 months, patients were divided into two groups: 29 patients with overt hypothyroidism requiring levothyroxine replacement and 20 without overt hypothyroidism. We compared changes in post-radioiodine thyroid volume between the two groups.

RESULTS

About 90% of patients whose thyroid volume at 3 months after iodine-131 administration was less than 50% of the original volume were hypothyroid by one year after treatment (positive predictive value 88%, sensitivity 75.9%, specificity 85.0%).

CONCLUSIONS

We believe ultrasonographic measurement of thyroid volume at 3 months after iodine-131 to be clinically useful for predicting post-treatment hypothyroidism in adolescent Graves' disease patients.

Serum PBDEs and age at menarche in adolescent girls: analysis of the National Health and Nutrition Examination Survey 2003-2004

BACKGROUND

Polybrominated diphenyl ethers (PBDEs), widely used as flame retardants since the 1970s, have exhibited endocrine disruption in experimental studies. Tetra- to hexa-BDE congeners are estrogenic, while hepta-BDE and 6-OH-BDE-47 are antiestrogenic. Most PBDEs also have antiandrogenic activity. It is not clear, however, whether PBDEs affect human reproduction.

OBJECTIVES

The analysis was designed to investigate the potential endocrine disruption of PBDEs on the age at menarche in adolescent girls.

METHODS

We analyzed the data from a sample of 271 adolescent girls (age 12-19 years) in the National Health and Nutrition Examination Survey (NHANES), 2003-2004. We estimated the associations between individual and total serum BDEs (BDE-28, -47, -99, -100, -153, and -154, lipid adjusted) and mean age at menarche. We also calculated the risk ratios (RRs) and 95% confidence intervals (CI) for menarche prior to age 12 years in relation to PBDE exposure.

RESULTS

The median total serum BDE concentration was 44.7ng/g lipid. Higher serum PBDE concentrations were associated with slightly earlier ages at menarche. Each natural log unit of total BDEs was related to a change of -0.10 (95% CI: -0.33, 0.13) years of age at menarche and a RR of 1.60 (95% CI: 1.12, 2.28) for experiencing menarche before 12 years of age, after adjustment for potential confounders.

CONCLUSION

These data suggest high concentrations of serum PBDEs during adolescence are associated with a younger age of menarche.

Thyroid function and human reproductive health

Via its interaction in several pathways, normal thyroid function is important to maintain normal reproduction. In both genders, changes in SHBG and sex steroids are a consistent feature associated with hyper- and hypothyroidism and were already reported many years ago. Male reproduction is adversely affected by both thyrotoxicosis and hypothyroidism. Erectile abnormalities have been reported. Thyrotoxicosis induces abnormalities in sperm motility, whereas hypothyroidism is associated with abnormalities in sperm morphology; the latter normalize when euthyroidism is reached. In females, thyrotoxicosis and hypothyroidism can cause menstrual disturbances. Thyrotoxicosis is associated mainly with hypomenorrhea and polymenorrhea, whereas hypothyroidism is associated mainly with oligomenorrhea. Thyroid dysfunction has also been linked to reduced fertility. Controlled ovarian hyperstimulation leads to important increases in estradiol, which in turn may have an adverse effect on thyroid hormones and TSH. When autoimmune thyroid disease is present, the impact of controlled ovarian hyperstimulation may become more severe, depending on preexisting thyroid abnormalities. Autoimmune thyroid disease is present in 5-20% of unselected pregnant women. Isolated hypothyroxinemia has been described in approximately 2% of pregnancies, without serum TSH elevation and in the absence of thyroid autoantibodies. Overt hypothyroidism has been associated with increased rates of spontaneous abortion, premature delivery and/or low birth weight, fetal distress in labor, and perhaps gestation-induced hypertension and placental abruption. The links between such obstetrical complications and subclinical hypothyroidism are less evident. Thyrotoxicosis during pregnancy is due to Graves' disease and gestational transient thyrotoxicosis. All antithyroid drugs cross the placenta and may potentially affect fetal thyroid function.

Incidence of thyrotoxicosis in childhood: a national population based study in the UK and Ireland

OBJECTIVE

To measure the UK and Ireland incidence of childhood (<15 years) thyrotoxicosis and to describe the presenting features.

CONTEXT

Incidence data on thyrotoxicosis in childhood are not available for the UK and Ireland. Recent studies have reported an apparent increase in cases in Europe.

DESIGN

A national prospective surveillance study for 12 months from September 2004, co-ordinated by The British Paediatric Surveillance Unit (BPSU).

PATIENTS AND MEASUREMENTS

All paediatricians across the UK and Ireland were requested monthly to report new cases. Details of presenting features were then obtained by questionnaire.

RESULTS

One hundred ten cases of acquired childhood thyrotoxicosis were identified in the UK and Ireland. The incidence of acquired thyrotoxicosis was 0.9 per 100,000 <15 years olds in the UK and Ireland, (95% CI: 0.8-1.1). Autoimmune thyrotoxicosis accounted for 96% of cases. There was an increasing incidence with age in each sex. Females have a significantly higher incidence than males in the 10- to 14-year age group. A variety of presenting symptoms were reported: weight loss (64%), fatigue/tiredness (54%), change in behaviour' (50%) and heat intolerance (47%). 4.5 % cases were asymptomatic. The commonest signs were goitre (78%) and tremor (58%). There were no cases of thyroid storm.

CONCLUSIONS

This national population survey defines the incidence of thyrotoxicosis in children in the UK and Ireland during 2004-2005, which was lower than expected in comparison with other European studies. The survey illustrates contemporary presenting characteristics of the disease.

Radioiodine treatment for pediatric hyperthyroid Grave's disease

Grave's disease (GD) is an autoimmune disease in which excessive amounts of thyroid hormones circulate in the blood. Treatment for pediatric GD includes (1) antithyroid drugs (ATD), (2) radioiodine, and (3) thyroidectomy. Yet, the optimal therapy remains controversial. We collected studies from all electronically available sources as well as from conferences held in China. All studies using radioiodine and/or ATD and/or thyroidectomy were included. Information was found on 1,874 pediatric GD patients treated with radioiodine, 1,279 patients treated with ATD and 1,362 patients treated surgically. The cure rate for radioiodine was 49.8%; the incidence of hypothyroidism, 37.8%; of relapse, 6.3%; of adverse effects, 1.55%; and of drop outs, 0.6%. These data show that radioiodine treatment is safe and effective in pediatric GD with significant lower incidence of relapse and adverse effects but significantly higher incidence of hypothyroidism as compared with both ATD and thyroidectomy. For the time being, radioiodine treatment for pediatric GD remains an excellent first-line therapy and a good second-line therapy for patients with ATD failure, severe complications, or poor compliance.

Pediatric thyroid-associated orbitopathy: the Children's Hospital of Philadelphia experience and literature review

BACKGROUND

As Graves' disease is uncommon in children, Graves' eye disease should be even more unusual. Here we report our experience with Graves' eye disease at the Children's Hospital of Philadelphia and review the literature on ophthalmic findings in children with Graves' disease.

SUMMARY

A retrospective review identified 152 children with Graves' disease seen in the endocrinology clinic of the Children's Hospital of Philadelphia over a 3-year period. Of this cohort, only 26 (17%) were referred to ophthalmology because of prominent ophthalmic manifestations. The ages of the patients ranged from 4 months to 17 years. Sixteen of 26 patients were female. Most patients had mild findings consistent with Graves' disease. Proptosis was noted in 10 of 26 (38%). Lid retraction was present in 6 of 26 (23%). Mild corneal punctuate staining was identified in only 3 of the 26 patients (12%). No patients had strabismus or optic neuropathy. Three newly diagnosed Graves' patients who were seen as the retrospective review was being completed were all girls. All three had normal vision, motility, and fundus exams. Two had mild proptosis, lid retraction, and lid lag on down gaze. None had corneal, motility, or optic nerve pathology. These findings are consistent with previous studies in the literature.

CONCLUSIONS

Eye findings in pediatric Graves' disease are usually mild and typically respond to local measures and control of disturbed thyroid function. Surgery is indicated in a small number of patients for cornea exposure or appearance issues. Graves' disease-associated optic neuropathy has never been reported in the pediatric population.

The treatment of Graves' disease in children

Graves' disease is the most common form of hyperthyroidism in childhood. Current treatment options include antithyroid medications, surgery, and radioactive iodine. Medical therapy is generally associated with long-term remission rates of less than 25% and a small risk of serious adverse reactions that include hepatic failure and bone marrow suppression. Total thyroidectomy is associated with very high cure rates and a small risk of hypoparathyroidism and recurrent laryngeal nerve damage. When radioactive iodine is used at appropriate doses, there is a very high cure rate without increased risks of thyroid cancer or genetic damage. Clinicians caring for the child or adolescent with Graves' disease are thus faced with using medications with potential short-term and long-term toxicity, for a condition in which spontaneous remission occurs in the minority of pediatric patients. Definitive therapy in the form of surgery or radioactive iodine is necessary and unavoidable for the majority of pediatric patients with Graves' disease.

Influence of gender and pubertal stage at diagnosis on growth outcome in childhood thyrotoxicosis: results of a collaborative study

OBJECTIVE

To evaluate the influence of sex as well as pubertal stage at diagnosis on the growth outcome of childhood thyrotoxicosis.

DESIGN

Retrospective, collaborative study.

PATIENTS AND METHODS

Longitudinal auxological evaluation in 101 patients (M/F 23/78) for 4.7 +/- 3.1 years subdivided according to pubertal stage at diagnosis into prepubertal (group I) and pubertal (group II).

RESULTS

At diagnosis height and bone age (BA) standard deviation score (SDS) were positive both in girls and boys of groups I and II. In boys of group II, height SDS was significantly higher than in girls of the same group (P = 0.007) and in boys of group I (P = 0.026). During the follow-up, in group I, height SDS remained positive without significant differences between boys and girls, and in group II, height SDS remained significantly lower in girls than in boys. The age at onset of puberty and the age at menarche were within the normal range. Final height (FH) was within target height (TH) range in all groups The FH SDS and the height gain (FH-TH) were similar in girls and in boys in group I and significantly higher in boys than in girls (P < 0.05) in group II. The boys of group II showed a mean height gain significantly greater than that found in all the other groups.

CONCLUSIONS

Despite the advancement of BA at presentation, there were no adverse effects on subsequent growth and FH; the growth outcome seems to be better in boys than in girls in group II.

Utilização do 131I no tratamento da doença de Basedow-Graves na infância e adolescência

Embora o diagnóstico da Doença de Graves (DG) na infância e adolescência seja relativamente fácil, seu tratamento ainda é controverso. Pode-se utilizar fármacos anti-tireoideanos (MMZ ou PTU), porém a incidência de efeitos adversos nessa faixa etária é maior que nos adultos e a taxa de remissão é baixa, mesmo com o uso prolongado. A cirurgia é pouco indicada como tratamento inicial, sendo realizada mais freqüentemente após recidiva do tratamento medicamentoso e/ou devido aos seus efeitos adversos. A utilização da radioiodoterapia na infância e adolescência vem crescendo. Com doses adequadas, ocorre o desenvolvimento de hipotireoidismo em cerca de 90% dos casos num período de 3 a 6 meses. Os dados iniciais sugerem que o tratamento em crianças acima de 5 anos não parece estar associado a maior risco de carcinoma de tireóide. A prevalência de efeitos adversos é menor que na cirurgia. Pacientes que apresentam fatores clínicos ou laboratoriais de pior prognóstico evolutivo podem ter seu tratamento medicamentoso encurtado, sendo a indicação da radioiodoterapia realizada mais precocemente.

Graves' disease in childhood

The vast majority of thyrotoxicosis cases in children are caused by Graves' disease (GD) and these account for 10-15% of all childhood thyroid diseases. The major clinical features of thyrotoxicosis in children are, in general, similar to those in adults. As in adults, the three conventional methods of treatment are antithyroid drugs (ATD), thyroidectomy and ablative radioiodine (131I). Although ATD are associated with side effects and a high relapse rate even after prolonged therapy, they still seem to be chosen as the first line of therapy for GD in childhood by most pediatric endocrinologists, although some have started using 131I as their first therapeutic modality. However, when ATD therapy has to be discontinued, or after relapse which may occur during or following ATD therapy, a definitive mode of therapy has to be chosen. Since thyroidectomy has the disadvantages of hospitalization and surgical complications, there is now an increasing tendency to advocate radioiodine as a choice of treatment in children older than five years old who achieve a high rate of remission. It should be kept in mind that with both thyroidectomy and radioiodine treatment, permanent hypothyroidism is very common and requires lifelong replacement therapy. According to the long-term follow-up data which have been published, radioiodine treatment in older children and adolescents seems to be safe and effective. Although studies of children with GD treated with ablative doses of radioiodine have not revealed an apparent increased risk of thyroid malignancy, a long-term study of larger populations is needed in order to define the true incidence of thyroid neoplasia, and other possible side effects, in children treated with radioiodine. Although the relatively low risks, low cost and practicability of radioiodine treatment has favored this therapy for children, as it has for adults, in the United States, it is still less attractive for European physicians. Progress in the immunological understanding of GD and of its genetic background will hopefully elucidate the pathways leading to GD, as well as the factors determining who is at high risk of developing GD, and may thus ultimately promote novel strategies for a more successful and safe therapy.

Thyroid disease and female reproduction

OBJECTIVE

To review the menstrual function and fertility in thyroid disease, mainly in hyperthyroidism and hypothyroidism. Also to register the consequences of (131)I therapy, which is used widely in the treatment of Graves' disease and thyroid cancer, on subsequent pregnancies and on fertility in these patients.

DESIGN

A MEDLINE computer search was used to identify relevant studies. The type of menstrual disturbances and the status of fertility were recorded from all the studies found. Also, the fertility and genetic hazard of female patients with Graves' disease and thyroid cancer who were treated with (131)I were registered.

RESULT(S)

Both hyperthyroidism and hypothyroidism may result in menstrual disturbances. Menstrual abnormalities are less common now than in previous series. In a recent study, we found that only 21.5% of 214 thyrotoxic patients had some type of menstrual disturbance, compared to 50 to 60% in some older series. The most common manifestations are hypomenorrhea and oligomenorrhea. According to the results of endometrial biopsies, most thyrotoxic women remain ovulatory. Moreover, the genetic hazard incident to radioiodine therapy in Graves' disease and thyroid carcinoma is very small; exposure to (131)I does not cause reduced fecundity, and the risk of loss of fertility is not a contraindication for its use in these patients. mIn hypothyroidism, the frequency of menstrual irregularities has very recently been reported to be 23.4% among 171 hypothyroid patients studied. This is much less than that reported in previous studies, which showed that 50 to 70% of hypothyroid female patients had menstrual abnormalities. The most common manifestation is oligomenorrhea. Severe hypothyroidism is commonly associated with failure of ovulation. Ovulation and conception can occur in mild hypothyroidism. These pregnancies are, however, often associated with abortions, stillbirths, or prematurity. The latter may be of greater clinical importance in infertile women with unexplained infertility.

CONCLUSION(S)

These new data, mainly concerning menstrual abnormalities in hyperthyroidism and hypothyroidism, are inconsistent with what is generally believed and written in the classic thyroid textbooks and indicate that such opinions should be revised.

The importance of the ligation of the inferior thyroid artery in parathyroid function after subtotal thyroidectomy

We prospectively studied the effects of the ligation of the inferior thyroid artery (ITA) on postoperative hypoparathyroidism in 48 patients who underwent functional subtotal thyroidectomy. Patients were randomized into two groups: A, with bilateral ligation of the ITA and B, without ligation of the ITA. Parathyroid function was checked preoperatively and after surgery by clinical examination and measurement of total calcium, intact PTH, urinary calcium, and AMPc.

RESULTS

A significant incidence of postoperative hypocalcemia occurred: 17% in group A and 13% in B on the 4th postoperative day. Six months later, the incidence was 5% in Group A and 0% in Group B. These differences were not statistically significant between the two groups, and neither were any of the other clinical and laboratory observations.

CONCLUSION

The ligation of the ITA was not an important causal factor for the occurrence of postoperative hypocalcemia after subtotal thyroidectomy.

The hypothalamic-pituitary-thyroid axis and the female reproductive system

Increasing evidence derived from experimental and clinical studies suggests that the hypothalamic-pituitary-thyroid axis (HPT) and the hypothalamic-pituitary-ovarian axis (HPO) are physiologically related and act together as a unified system in a number of pathological conditions. The suggestion that specific thyroid hormone receptors at the ovarian level might regulate reproductive function, as well as the suggested influence of estrogens at the higher levels of the HPT axis, seems to integrate the reciprocal relationship of these two major endocrine axes. Both hyper- and hypothyroidism may result in menstrual disturbances. In hyperthyroidism the most common manifestation is simple oligomenorrhea. Anovulatory cycles are very common. Increased bleeding may also occur, but it is rare. Hypothyroidism in girls can cause alterations in the pubertal process; this is usually a delay, but occasionally it can result in pseudo-precocious puberty. In mature women hypothyroidism usually is associated with abnormal menstrual cycles characterized mainly by polymenorrhea, especially anovulatory cycles, and an increase in fetal wastage.

Neuropsychiatric aspects of pediatric thyrotoxicosis

The neurobehavioural and neuropsychiatric changes associated with thyrotoxicosis are multiple and varied. This association is well recognised although the true incidence of neuropsychiatric symptoms in thyrotoxicosis is not known. Review of available literature suggests that frank psychiatric symptoms in thyrotoxicosis may be in the order of 10%. In pediatric thyrotoxicosis the neuropsychiatric symptoms may be pronounced and may antedate the medical diagnosis by six months to one year. One of the classic presentation is deterioration in school performance. Frequently noticed cognitive and behavioural abnormalities in pediatric thyrotoxicosis are hyperactivity, irritability or anxious dysphoria, and problems of attention. Successful treatment of thyrotoxicosis usually leads to resolution of the major mental disturbances associated with it and delayed treatment possibly results in enduring neuropsychiatric problems. Awareness of neuropsychiatric symptomatology can help in early detection and appropriate management of children with thyrotoxicosis.

Thyroid disorders in lithium-treated patients

BACKGROUND

Little is known about the rate of thyroid disorders prior to lithium treatment, and which patients have a higher risk for developing such disorders during such treatment.

METHOD

Assessment of the thyroid histories and laboratory results of 209 lithium-treated patients with affective disorders from one catchment area.

RESULTS

Six female patients had thyrotoxicosis before starting lithium, a rate of 4.9%. Twenty patients developed hypothyroidism during the treatment: 3.4% of all males and 14.9% of all females. Female patients over the age of 50 were more likely to develop early lithium-induced hypothyroidism.

CONCLUSIONS

(1) Female patients with affective disorders might have an increased rate of thyrotoxicosis. (2) Lithium-induced hypothyroidism might develop earlier in female patients over the age of 50.

LIMITATIONS

Retrospective design of the study.

CLINICAL RELEVANCE

(1) The thyroid status of patients with affective disorders might be more relevant than is appreciated. (2) Guidelines for thyroid tests in lithium-treated patients should reflect the different risks conferred by age and gender.

Thyrotoxicosis in children

Graves' disease is the predominant cause of hyperthyroidism in the pediatric age group. Other disorders must be recognized, however, because adequate management relies on a precise diagnosis. Careful monitoring of the thyroid status is required during this active phase of growth and development.

Childhood goitre in Saudi Arabia

Thirty-two Saudi children (aged 1.5-14 years) with goitre were seen over a 6.5-year period in a paediatric endocrinology clinic. There was a female to male ratio of 1.9:1. Of these, 27 (84.3%) had diffuse thyroid enlargement and five (15.7%) nodular goitre. The commonest causes were dyshormonogenesis (37.5%) followed by Hashimoto's thyroiditis (34.4%). Three boys and one girl had Graves' disease. There were three (9.4%) with simple goitre and one case each of iodine deficiency goitre and tuberculous thyroiditis. Further study of the prevalence and causes of goitre, including iodine deficiency goitre, in Saudi Arabia is suggested.

Atrial flutter: an uncommon pediatric manifestation of hyperthyroidism

OBJECTIVE

Atrial flutter is an uncommon arrhythmia in the pediatric population except for the immediate newborn period or following atrial repair of congenital heart disease. In children the diagnosis of atrial flutter may be difficult, attributable to rapid atrioventricular conduction and superimposition of flutter waves on QRS and T waves. Atrial flutter secondary to hyperthyroidism has been rarely reported in older adults, but there are no reports of children presenting with atrial flutter as the initial manifestation of hyperthyroidism.

CASE REPORT

We report an interesting case of hyperthyroidism in a 3-year-old presenting with congestive heart failure and atrial flutter with 1:1 atrioventricular conduction. The responses to adenosine administration and to cardioversion were unusual and ultimately helpful in suggesting the diagnosis of hyperthyroidism.

CONCLUSION

When atrial flutter is encountered in a pediatric patient in whom there is 1:1 atrioventricular conduction, a lack of a response to adenosine, and persistent sinus tachycardia after cardioversion, the clinician should be alert to the possibility of thyrotoxicosis.

T-cell recognition of residue 158-176 in thyrotropin receptor confers risk for development of thyroid autoimmunity in siblings in a family with Graves' disease

Twenty-two subjects in a family with Graves' Disease and 20 normal subjects unrelated to the family were examined for T-cell responses to rec h TSHR-ECD and its synthetic peptides. Seven of the family members and none of the controls responded positively to rec h TSHR-ECD. Peptide 158-176 was the only residue that showed a high percentage of response among family members, no responses in spouses, and a significant difference compared to unrelated controls. Family members under age of 6 did not differ from spouses in response to rec h TSHR-ECD or any individual peptide. Family members ages 6-12 years were significantly different from spouses in response to peptides 30-49, 158-176, and 172-186. The reactivity of adult family members including 3 Graves' patients was significantly different from spouses in response to peptides 44-62, 132-150, 158-176, and 248-263. The responses of female members of the family were higher than that of the male members and significantly different for peptide 272-291. These data suggest that recognition of peptide 158-176 may be an early event in the pathogenesis of the disease and that recognition of both 158-176 and 248-263 residues may be the cornerstone for establishment of the disease.

Thyroid diseases in a school population with thyromegaly

A survey of 5462 schoolchildren was conducted for signs of thyroid disease in the seaside region of Sibenik, Croatia. In this region, salt is regularly iodised with 0.01% potassium iodide. Thyromegaly was found in 152 children (2.8%). The most common disorder was simple goitre, which was established in 126 of these, 12 boys and 114 girls (combined prevalence of 2.3%, and of 0.45% in boys and 4.07% in girls). Juvenile autoimmune thyroiditis was found in 19 of the children (prevalence 0.35%), with a female:male sex ratio of 8:1. Diagnosis was confirmed in all cases by fine needle biopsy. Thyroglobulin antibodies were detected in all 19 of the patients with juvenile autoimmune thyroiditis, but microsomal antibodies in only eight. Three patients had decreased concentrations of thyroxine and raised concentrations of thyroid stimulating hormone (TSH), one of these also with clinical hypothyroidism. Raised concentrations of TSH but with normal triiodothyronine and thyroxine were seen in two patients. Graves' disease was diagnosed in four children, three girls and one boy (combined 0.07%). Thyroid nodules were identified in three children (0.055%; two benign adenomas and one cyst). Only seven of the 152 patients with thyromegaly (three with hyperthyroidism and four with simple goitre) had previously sought medical advice, which points to the need for careful thyroid examination of apparently healthy children even in regions where the regular iodide intake is assumed to be sufficient.

A rat model of thyroid hormone-induced bone loss: effect of antiresorptive agents on regional bone density and osteocalcin gene expression

Thyroid hormone has been shown to stimulate bone resorption. Both endogenous hyperthyroidism and exogenous thyroxine suppressive therapy have been associated with reduction in bone mineral density (BMD), but the patholophysiology of thyroxine-induced bone loss is not well understood. First we studied the effect of L-T4 (0.1-0.3 microgram/g body weight ip/day) on bone turnover in rats by measuring regional BMDs and osteocalcin mRNA. Next we determined whether antiresorptive agents (calcitonin 1 microU/gip/day or sodium etidronate given cyclically at 10 micrograms/g po for 3 consecutive days out of every week) could prevent bone loss. Groups of 10 male Sprague-Dawley rats each weighing 320-350 g were studied before and after 3 weeks of treatment. L-T4 treatment resulted in reduction in BMDs in the lumbar spine, tail, and femur as measured by dual energy X-ray absorptiometry, but there was no correlation with the dosage of L-T4 or the serum T4 level. Treatment with sodium etidronate or calcitonin alone did not alter the regional BMD. Cyclical sodium etidronate, but not calcitonin, was able to prevent the bone loss induced by L-T4 treatment. L-T4 caused a dose-dependent increase in femur osteocalcin mRNA concentration. Treatment with calcitonin resulted in 50% reduction of osteocalcin mRNA, but sodium etidronate had no effect. In conclusion, cyclical sodium etidronate prevents bone loss induced by exogenous L-T4 in rats and may be useful in preventing osteoporosis in patients given long term TSH-suppressive doses of thyroxine therapy.

Late results of thyroid surgery for hyperthyroidism performed in childhood

The authors report on the complex follow-up of 60 patients operated on for hyperthyroidism in childhood, on average 13.7 years after surgery. In 16.7% of the patients manifest hypothyroidism, in 45% subclinical hypothyroidism was found; 30% of the patients were euthyroid, and manifest hyperthyroidism recurred in 8.3%. Autonomous adenomas were enucleated in two children and three young adults. Severe disorders in thyroid function developed especially after the surgery of diffuse toxic goiters accompanied by ophthalmopathy. The disorders of humoral and cellular immunity were detected most frequently in recurrent manifest hyperthyroidism. There was no case where ophthalmopathy progressed after the operation. In the offspring of the operated patients the incidence of hyperthyroidism was not increased in childhood. The authors call attention to the importance of postoperative follow-up and hormone treatment.

Hyperthyroidism in children and adolescents

Hyperthyroidism in infants and children usually is caused by Graves' disease; however, several other diseases can also produce hyperthyroidism in these age groups. Because the pathophysiology and clinical course of these conditions differ, optimal treatment depends on precise diagnosis.

Alopecia areata, endocrine function, and autoantibodies in patients 16 years of age or younger

Forty-five children with alopecia areata were prospectively studied by means of both clinical and laboratory evaluation for evidence of endocrine diseases and autoantibodies. Twenty-four percent had an abnormality as determined by one or more thyroid function studies (thyroxine, triiodothyronine, and thyroid-stimulating hormone) and/or elevation of microsomal antibody levels. In 16%, smooth muscle antibody was present, and in 4%, parietal cell antibody was present. Routine thyroid function testing is recommended for all children with alopecia areata.

Surgery for thyroid disease

Thyroidectomy is the keystone of management in most patients with thyroid cancer, and has unique advantages in many cases of hyperthyroidism. The role of thyroidectomy in these two conditions is considered, with specific discussion of indications, extent of operation, complications, and technique.

Childhood hyperthyroidism. Results of treatment

40 hyperthyroid children were followed for 0.2--12 (mean 4.5) years. The treatment was antithyroid drugs in 20, subtotal thyroidectomy after a drug trial in 18 and primary thyroidectomy in 2 patients. 4 patients who relapsed (3 after surgery and 1 after a drug trial) were given radioiodide. 11 of the surgically treated glands were nodular. At the follow-up study 24 patients were euthyroid, 7 were on thyroxine therapy and in 5 others hypothyroidism was discovered. 2 subjects were still on antithyroid drugs and 2 relapsed. In 5 euthyroid patients the TRH test revealed a low thyroid reserve. In 28 of 34 subjects examined circulating antibodies to thyroid microsomes were present in high titres. Evidently, regular follow-up is needed because of the high risk of hypothyroidism.

Selection of treatment in the management of thyrotoxicosis in childhood and adolescence

The management of 105 patients between the ages of three and 18 years, 83 females and 22 males, with thyrotoxicosis was reviewed retrospectively (1952-1976) with the intent of identifying criteria that would help predict response to therapy with antithyroid drugs and thereby permit earlier selection of alternative treatment. All patients were initially treated with antithyroid drugs. Twenty-six per cent (27) achieved remission with thioamides, 68% (72) underwent subtotal thyroidectomy with three patients requiring subsequent therapy with radioiodine, 6% (6) received radioiodine with one patient subsequently requiring subtotal thyroidectomy. Failure of remission after thioamide therapy was related to drug toxicity, persistent disease, noncompliance and recurrence after an initial remission. During the last decade there was earlier selection of subtotal thyroidectomy based on prior experience. The most significant discriminants were sex, age, and regression of thyromegaly. Ninety-one per cent of the males, 89% of children over 11 years of age and all patients who had no regression of their thyromegaly after a sustained period of control of their thyrotoxicosis by thioamide therapy received subtotal thyroidectomy or radioiodine therapy for control of their thyrotoxicosis. Recognition of these factors at the time of diagnosis should permit earlier selection of the most suitable treatment and expedite patient care. Subtotal thyroidectomy has a low morbidity and is effective treatment for thyrotoxicosis in adolescence and childhood.

Thryo-endocrine pathology, obstetric morbidity and schizophrenia: survey of a hundred families with a schizophrenic proband

This preliminary communication reports that the mothers of 104 schizophrenic patients had: (1) a significantly higher incidence of thyroid disease than a carefully matched control group; (2) significantly more abortions, still-births and greater infant mortality. The findings and possible relevance of thyroid disease to schizophrenia are discussed. Three prospective studies currently in progress are outlined.

Concurrence of Grave's disease and Hashimoto's thyroiditis

Early histological changes in the thyroid gland were examined in 30 patients with juvenile thyrotoxicosis, by means of needle biopsy. Based on the degree of lymphocytic infiltration and degenerative changes in follicular epithelium, results were classified into four groups. A: hyperplastic changes without cellular infiltration (6 patients, 20%); B: hyperplastic changes with areas of focal thyroiditis less than 30% of specimen (10 patients, 33%); C: those with 30 to 60% areas ot thyroiditis (10 patients, 33%); D: almost diffuse thyroiditis (4 patients, 13%). Moderate to severe lymphocytic thyroiditis was frequently present in the early stage of hyperplastic thyroid glands. The clinical significance of the 4 histological groups was evaluated. Neither clinical signs nor routine laboratory tests could differentiate these groups except group D, in which thyrotoxic signs were mild and transient. However, serum antithyroid antibodies tended to increase in accordance with severity of thyroiditis. The rate of remission was high in groups C and D, whereas relapse was frequent in group A. These results suggest that Grave's disease and chronic lymphocytic thyroiditis are closely related in the early stage of thyrotoxicosis in children, and that the clinical course may be considerably altered by the degree of associated thyroiditis.

Antithyroid drug therapy for toxic diffuse goiter (Graves disease): thirty years experience in children and adolescents

Since 1946 104 children and adolescents with toxic diffuse goiter have been treated. Sixty-seven were treated with a thioamide for more than 12 months. Remission occurred in 61%. Twenty-five patients had a 12-hour perchlorate discharge test to determine the least frequent dose schedule required for disease control: 68% could be controlled on a single daily dose and an additional 25% on an every 12-hour schedule. A one-hour radioiodine uptake on combined therapy and change in thyroid gland size during treatment were found to be highly correlated with the presence of a spontaneous remission. Thirty-six patients have been treated by subtotal thyroidectomy. To date 65% have developed permanent hypothyroidism. In the author's opinion, thoamides are the treatment of choice for the majority of children and adolescents.

Radioactive iodine therapy for thyrotoxicosis

Radioactive iodine has been used to treat over 300,000 thyrotoxic patients since 1946. This paper reviews the knowledge gained in the past 23 years about the efficacy and safety of 131I therapy for thyrotoxicosis. Modifications with reference to case selection, dosage, and follow-up are discussed.