Graves' disease

Thyroid function abnormalities in HIV-infected patients

Abnormal thyroid function test results are common among human immunodeficiency virus (HIV)-infected patients. Although the prevalence of overt thyroid disease does not appear to be significantly increased in HIV-infected patients, compared with the general population, specific patterns of abnormal thyroid function test findings are more frequently identified among HIV-infected patients. Among patients with advanced acquired immunodeficiency syndrome, nonthyroidal illness (i.e., euthyroid sick syndrome) is common. During antiretroviral therapy, the prevalence of 2 generally asymptomatic conditions (subclinical hypothyroidism, which is characterized by isolated elevated thyroid-stimulating hormone levels, and isolated low free thyroxine levels) is increased. In addition, Graves disease, which is marked by low thyroid-stimulating hormone and elevated thyroxine levels, may occur during immune reconstitution. Testing for thyroid disease among symptomatic patients should begin with measurement of the thyroid-stimulating hormone level. However, there is insufficient evidence to recommend routine thyroid screening of asymptomatic HIV-infected individuals. This review summarizes the current evidence regarding the optimal laboratory evaluation of thyroid function; highlights the causes, presentation, and treatment of thyroid dysfunction in HIV-infected patients; and discusses the controversies regarding screening.

Propylthiouracil Versus Methimazole in Treatment of Graves' Disease During Pregnancy

OBJECTIVE:

To evaluate the evidence supporting the use of propylthiouracil (PTU) versus methimazole for the treatment of Graves' disease during pregnancy.

DATA SOURCES:

An English-language literature search was conducted using MEDLINE (1966–March 2007). Identified articles were then reviewed for additional sources. Search terms included hyperthyroidism, Graves' disease, pregnancy, propylthiouracil, and methimazole.

STUDY SELECTION AND DATA EXTRACTION:

All clinical trials and case reports that were published in English and reported either subjective or objective outcomes were reviewed.

DATA SYNTHESIS:

Rationale supporting the use of PTU over methimazole in treatment of Graves' disease during pregnancy is limited. Theories suggesting that PTU has less placental transfer to the fetus than methimazole are not supported by current literature. Studies demonstrating a causal relationship between methimazole use during pregnancy and congenital anomalies and/or fetal hypothyroidism do not exist.

CONCLUSIONS:

The selection of PTU versus methimazole for the treatment of Graves' disease during pregnancy should not be based solely on the following assumptions: that PTU crosses the placenta less than methimazole, that PTU leads to less fetal hypothyroidism, or that exposure to methimazole during pregnancy leads to decreased intellectual function in children. However, due to a possible association between the use of methimazole during pregnancy and fetal anomalies such as aplasia cutis, esophageal atresia, and choanal atresia, methimazole may be a less desirable first-line treatment for Graves' disease in pregnancy than PTU. Therefore, in the absence of a compelling indication for the use of methimazole, PTU should still be considered as the first-line agent in the treatment of Graves' disease during pregnancy. Methimazole should be considered a viable second choice if the patient is intolerant to PTU, has an allergic reaction to PTU, or fails to become euthyroid while receiving PTU.

CONCLUSIONES:

La selección de PTU versus metimazole en el tratamiento de enfermedad de Graves durante el embarazo no debe ser basada en la siguiente información: 1que PTU cruza la placenta a un menor grado que metimazole, que PTU se asocia con menos hipotiroidismo fetal, ó que la exposición a metimazole durante el embarazo lleva a una disminución en la función intelectual en niños. Sin embargo, debido a una posible asociación entre el uso de metimazole durante el embarazo y anormalidades fetales tales como aplasia cutis, atresia esofageal y atresia choanal, metimazole podría ser una alternativa de primera línea menos deseable para el tratamiento de enfermedad de Graves durante el embarazo que PTU. Por lo tanto, en la ausencia de indicación contundente para el uso de metimazole, PTU debe considerarse el agente de primera línea en el tratamiento de enfermedad de Graves durante el embarazo. Sin embargo, metimazole puede considerarse un agente alterno si el paciente no tolera el PTU, tiene reacción alérgica a PTU o falla en convertir a eutirodeo con PTU. RÉSUMÉ: Il existe peu de justification à l'utilisation du PTU plutôt que du methimazole. Certaines théories suggérant que le PTU traverse moins la barrière placentaire ne sont pas, à l'heure actuelle, supportées par des évidences. Les études démontrant une relation de cause à effet entre le methimazole et des anomalies congénitales et/ou de l'hypothyroïdisme chez le fétus n'existent pas.

Radioiodine treatment for benign thyroid diseases

Radioiodine has been in use for over 60 years as a treatment for hyperthyroidism. Major changes in clinical practice have occurred with the realization that accurate dosimetry is incapable of avoiding the risks of hypothyroidism, while more accurate assessment of the risks of other adverse effects of radioiodine such as ophthalmopathy and carcinogenesis have become available. More is also known of the potential for pretreatment with an antithyroid drug to affect the outcome of radioiodine treatment. However, we are still uncertain of the benefits of radioiodine treatment in subclinical hyperthyroidism. During the last two decades there has been wider acceptance of radioiodine as a safe and effective therapy for benign, nontoxic goitre, coupled with waning enthusiasm for the use of levothyroxine, as the risks and benefits of this option have become more apparent. The use of recombinant TSH offers the prospect that radioiodine treatment of nontoxic goitre can be simplified and improved, although more studies of this strategy are urgently required.

Effect of lugol solution on thyroid gland blood flow and microvessel density in the patients with Graves' disease

CONTEXT

Although some endocrine surgeons administer Lugol solution to decrease thyroid gland vascularity, there is still not an agreement on its effectiveness.

OBJECTIVE

The aims of this clinical trial are to evaluate thyroid blood flow and microvessel density in patients with Graves' disease who received Lugol solution treatment preoperatively.

DESIGN

This was a prospective clinical trial.

SETTING

This clinical trial took place at a tertiary referral center.

METHOD

Thirty-six patients were randomly assigned to receive either preoperative treatment with Lugol solution (group 1, n = 17) or no preoperative treatment with Lugol solution (group 2, n = 19).

MAIN OUTCOME MEASURES

Blood flow through the thyroid arteries of patients with Graves' disease was measured by color flow Doppler ultrasonography. The microvessel density (MVD) was assessed by immunohistochemical and Western blot analysis of the level of expression of CD-34 in thyroid tissue. The weight and blood loss of the thyroid gland were measured in all patients.

RESULTS

The mean blood flow, MVD, CD-34 expression, and blood loss in group 1 patients were significantly lower than those in group 2 patients. There was a negative correlation between Lugol solution treatment and blood flow (r(s) = -0.629; P = 0.0001), blood loss (r(s) = -0.621; P = 0.0001), MVD (r(s) = -0.865; P = 0.0001), and CD-34 expression (r(s) = -0.865; P = 0.0001). According to logistic regression analysis, Lugol solution treatment resulted in a 9.33-fold decreased rate of intraoperative blood loss.

CONCLUSION

Preoperative Lugol solution treatment decreased the rate of blood flow, thyroid vascularity, and intraoperative blood loss during thyroidectomy.

Circulating mononuclear cells from euthyroid patients with thyroid-associated ophthalmopathy exhibit characteristic phenotypes

Thyroid-associated ophthalmopathy (TAO) is a common yet poorly understood component of Graves' disease involving inflammation, congestion and soft tissue remodelling of the orbit. Unlike most autoimmune disorders, TAO has variable severity but follows a predictable course and is usually self-limited. The objective of this study was to investigate the phenotypic profile of peripheral blood mononuclear cells in euthyroid patients with TAO. The study was a prospective, consecutive analysis of the peripheral blood mononuclear cell phenotype in patients with TAO and normal controls. We demonstrate that the fraction of T cells expressing CD69, CD25 or CXCR4 is significantly greater in patients with TAO compared to control donors. In addition, the fraction of CD19(+) CD25(+) B cells is significantly greater. We did not find differences between the two groups of subjects in monocytes expressing these markers. There is a phenotypic shift in peripheral blood lymphocytes associated with TAO that appears durable and persists beyond the hyperthyroid phase of Graves' disease. These changes may support the immune reaction provoking orbital disease development.

Linkage of Graves' disease to the human leucocyte antigen region in the Chinese-Han population in Taiwan

OBJECTIVE

To investigate whether markers in the candidate chromosome regions, including the human leucocyte antigen (HLA) region, are linked to Graves' disease (GD).

DESIGN

A familial linkage study with a candidate region approach.

PATIENTS

A total of 536 individuals in 122 multiplex Chinese-Han families with a GD proband and at least one other affected sibling, resulting in 270 affected sib-pairs. Subjects with a family history of noniatrogenic hypothyroidism or Hashimoto's thyroiditis were excluded.

MEASUREMENTS

We genotyped eight short tandem repeat polymorphism (STRP) markers in a 13.7 cM region covering the HLA region on chromosome 6p21 and 26 STRPs in four other candidate regions previously reported in the literature.

RESULTS

Multipoint nonparametric linkage (NPL) analysis showed significant linkage to the HLA region [the marker UniSTS:239159, nonparametric log of odds (LOD) score 3.44, P = 0.00003; NPL Z-score 4.1, P = 0.00002] from 270 affected sib-pairs. The 1-LOD support interval comprised the whole HLA region (ca. 4 Mb). By contrast, the maximal NPL Z-scores of the markers of the other candidate regions (2q33, 5q31, 7q22 and 14q31) previously reported were all less than 1.0.

CONCLUSIONS

Our results provide strong support for linkage of GD to the HLA region. Further dissection of this region to identify the candidate gene for GD is warranted in our population.

Chinese herbal medicines for hyperthyroidism

BACKGROUND

Hyperthyroidism is a disease in which excessive amounts of thyroid hormones circulate in the blood. Patients, among other things suffer from tachycardia, warm moist skin and raised body temperature. The treatment of hyperthyroidism includes symptom relief and therapy with antithyroid medications, radioiodine and thyroidectomy. Medicinal herbs are used alone or in combination with antithyroid agents to treat hyperthyroidism in China and some other countries.

OBJECTIVES

To assess the effects of Chinese herbal medicines for treating hyperthyroidism.

SEARCH STRATEGY

Studies were obtained from computerised searches of MEDLINE, EMBASE, The Cochrane Library, the Chinese Biomedical Database.

SELECTION CRITERIA

Randomised controlled trials comparing the effects of Chinese herbal medicines alone with Chinese herbal medicines combined with antithyroid drugs, radioiodine or both.

DATA COLLECTION AND ANALYSIS

Three authors interviewed authors of all potentially relevant studies by telephone to verify randomisation procedures. One author entered data into a data extraction form and another author verified the results of this procedure.

MAIN RESULTS

Thirteen relevant trials with 1770 participants were included. All of them were of low quality. Fifty-two studies still need to be assessed because the original authors could not be interviewed. None of these trials analysed mortality, health related quality of life, economic outcomes or compliance. Compared to antithyroid drugs alone the results showed that Chinese herbal medicines combined with antithyroid drugs may offer benefits in lowering relapse rates, reducing the incidence of adverse effects, relieving symptoms, improving thyroid antibody status and thyroid function. Two trials investigated Chinese herbal medicine versus radioiodine and reported improvements in anxiety, tachycardia and heat intolerance. However, thyroid function - with the exception of restored thyroid stimulating hormone (TSH) - was not significantly altered.

AUTHORS' CONCLUSIONS

The results suggest that traditional Chinese herbal medicines added to other routine treatment have a therapeutic potential for people with hyperthyroidism. However, due to methodological limitations, we could not identify a well-designed trial to provide strong evidence for Chinese traditional herbal medicine in the treatment of hyperthyroidism. Thus, we currently cannot recommend any single preparation or formulation for clinical use.

Intercellular adhesion molecule 1 gene polymorphisms do not contribute to Graves' disease in Chinese patients

OBJECTIVE

In order to study the association of G241R polymorphism of ICAM-1 gene with an earlier onset of Graves' disease (GD) and the susceptibility of K469E polymorphism to Graves' ophthalmopathy (GO) in Chinese population.

STUDY DESIGN

A case-control and replication study was performed in 212 GD patients and 204 healthy subjects to analyze the genotypes. Furthermore the distribution of ICAM-1 genotypes was investigated in subgroups of patients with GD according to the onset age and the ophthalmopathy.

RESULTS

No G241R polymorphism of ICAM-1 gene was detected in Chinese. No significant differences of allele and genotype frequencies regarding K469E polymorphism were found between GD patients and healthy controls (chi2 = 0.092, P = 0.762; chi2 = 1.089, P = 0.580). In addition, the genotype-phenotype correlation was not identified either.

CONCLUSIONS

We found no association of G241R and K469E polymorphisms of the ICAM-1gene with the development of GD in a Chinese population. However, we could not rule out possible contributions of other polymorphisms of the ICAM-1gene to the pathogenesis of GD. Therefore, further studies are needed to elucidate the role of ICAM-1gene in Graves' disease in different population.

Neonatal hyperthyroidism: neonatal clinical course of two brothers born to a mother with Graves-Basedow disease, before and after total thyroidectomy

BACKGROUND

About 1-2% of infants born to mothers with Graves' disease or Hashimoto's thyroiditis develop neonatal hyperthyroidism because of transplacental passage of IgG stimulating TSH receptors (TRAb).

OBJECTIVE

To evaluate the effect of maternal total thyroidectomy on neonatal clinical course.

METHODS

We describe two brothers born to a mother with Graves' disease, before and after total thyroidectomy.

RESULTS

The first child showed persistent tachycardia, the presence of TRAb and a laboratory pattern of hyperthyroidism. Lugol's solution was started and then propylthiouracil was added. Digitalis, furosemide and diazepam were necessary for treatment of heart failure, hypertension and irritability. On the 70th day of life, hormone serum levels normalized and treatment was interrupted. TRAb normalized by the third month of life. The second infant was born 2 years after the mother underwent total thyroidectomy. In spite of a laboratory pattern of hyperthyroidism and positivity to TRAb, he showed only considerable weight loss, and no therapy was required.

CONCLUSIONS

TRAb may persist after total thyroidectomy: clinical and instrumental follow-up of the newborn is recommended.

An optimal treatment for pediatric Graves' disease is radioiodine

CONTEXT

Antithyroid medications, surgery, and radioactive iodine have been used for more than five decades for the treatment of hyperthyroidism due to Graves' disease in children, adolescents, and adults. Despite the widespread use of these different approaches, controversy still exists relative to the merits of each treatment, especially regarding the use of radioactive iodine.

OBJECTIVE

The objective of the study was to address the risk and benefits of (131)I therapy, as compared with other treatment approaches. POSITION: Long-term, spontaneous remission of Graves' disease occurs in less than 30% of children. Thus, the majority of children with Graves' disease will need definitive, curative therapy. There is little evidence that use of antithyroid medications beyond 1 or 2 yr increases the likelihood of spontaneous, long-term remission. Although the use of antithyroid medications is standard practice, the use of antithyroid medications involves definite risks. When used at sufficient doses, radioactive iodine is an effective cure for Graves' disease and is associated with few acute side effects. Potential long-term adverse side effects, including thyroid cancer and genetic damage, have yet to be observed in individuals treated as children or adolescents with (131)I.

CONCLUSION

Properly administered, radioactive iodine remains an ideal form of treatment for Graves' disease in the pediatric population. Because of the increased risk of thyroid cancer associated with low-dose thyroid irradiation in children, larger, rather than smaller, doses of (131)I should be given.

Cytokine promoter polymorphisms in Taiwanese patients with Graves' disease

OBJECTIVES

This study aimed to examine the association between promoter polymorphisms of Th1 and Th2 cytokine genes [interleukin-4 (IL-4 T-34C, A-81G, C-285T and T-589C), IL-6 (G-174C), IL-10 (A-592C and T-819C) and tumour necrosis factor-alpha (TNF-alpha G-238A and G-308A)] and Graves' disease (GD) in Taiwanese population.

DESIGN AND METHODS

Genomic DNA was extracted from peripheral blood cells of 137 GD patients and 189 control subjects. Cytokine gene polymorphisms were analyzed by polymerase chain reaction and restriction fragment length polymorphism.

RESULTS

Genotype frequencies of TNF-alpha G-238A or G-308A between control and GD subjects were significantly different. Frequencies of the high TNF-alpha secreting alleles (-238*A and -308*A) and IL-10 -819*C allele were significantly increased in GD patients. No significant differences regarding IL-4 or IL-6 gene polymorphisms between GD patients and control subjects were found.

CONCLUSIONS

Our data demonstrated that TNF-alpha G-238A and G-308A genotypes were strongly associated with GD incidence.

Psychiatric manifestations of Graves' hyperthyroidism: pathophysiology and treatment options

Graves' disease is an autoimmune disorder that is the most common cause of hyperthyroidism. Other symptoms associated with the disease are goitre, ophthalmopathy, and psychiatric manifestations such as mood and anxiety disorders and, sometimes, cognitive dysfunction. Graves' hyperthyroidism may result in these latter manifestations via the induction of hyperactivity of the adrenergic nervous system. This review addresses the psychiatric presentations, and their pathophysiology and treatment, in patients with hyperthyroidism, based on literature identified by a PubMed/MEDLINE database search. Although the focus is on mental symptoms associated with Graves' disease, it is not always clear from the literature whether patients had Graves' disease: in some studies, the patients were thought to have Graves' disease based on clinical findings such as diffuse goitre or ophthalmopathy or on measurements of thyroid antibodies in serum; however, in other studies, no distinction was made between Graves' hyperthyroidism and hyperthyroidism from other causes. Antithyroid drugs combined with beta-adrenoceptor antagonists are the treatments of choice for hyperthyroidism, as well as for the psychiatric disorders and mental symptoms caused by hyperthyroidism. A substantial proportion of patients have an altered mental state even after successful treatment of hyperthyroidism, suggesting that mechanisms other than hyperthyroidism, including the Graves' autoimmune process per se and ophthalmopathy, may also be involved. When psychiatric disorders remain after restoration of euthyroidism and after treatment with beta-adrenoceptor antagonists, specific treatment for the psychiatric symptoms, especially psychotropic drugs, may be needed.

Benign thyroid disease: what is the role of nuclear medicine?

Nuclear medicine is directly involved in both the diagnosis and treatment of benign thyroid disease, which requires an understanding of the pathophysiology and management of thyroid disorders in addition to expertise in nuclear methodology. Thyroid uptake and imaging, the principal nuclear tests in thyroid disease, may be used as follows: (1) Differential diagnosis of hyperthyroidism: A very low thyroid uptake suggests destructive ("subacute") thyroiditis, a self-limited disorder, whereas a normal or elevated uptake is consistent with toxic nodular goiter and Graves' disease. Scintigraphic characteristics also help differentiate between nodular and Graves' disease. (2) Function of thyroid nodules: Fine-needle aspiration biopsy with cytological examination (FNAB) is used routinely to assess for malignancy in thyroid nodules. Scintigraphy may be of assistance before FNAB. "Hot" nodules are generally benign and do not require FNAB, while "cold" nodules may be malignant. (3) Differential diagnosis of congenital hypothyroidism: Scintigraphy combined with ultrasound examination may be used to identify such conditions as thyroid agenesis, dyshormonogenesis, and incomplete thyroid descent. Treatment of Graves' disease and toxic nodular disease with (131)I may require greater clinical involvement and decision analysis compared with thyroid uptake and imaging. The following aspects of treatment are particularly important: (1) Risk: Radioiodine treatment may occasionally aggravate hyperthyroidism, Graves' ophthalmopathy, and airway obstruction caused by large, nodular goiters. Alternative treatments, including the temporary use of antithyroid drugs, and surgery for nodular goiters, may be considered. (2) Radioiodine dose: Cure of hyperthyroidism with a single (131)I treatment is desirable, though not always possible. Such factors as a large goiter, severe hyperthyroidism, and prior propylthiouracil therapy, may contribute to treatment failure. (3) Informed consent: A detailed discussion with the patient regarding the clinical risks, outcomes, and side effects of (131)I is a critical component of successful management.

Thyroid disease in pregnancy

Thyroid testing during pregnancy should be performed on symptomatic women or those with a personal history of thyroid disease. Overt hypothyroidism complicates up to 3 of 1,000 pregnancies and is characterized by nonspecific signs or symptoms that are easily confused with complaints common to pregnancy itself. Physiologic changes in serum thyroid-stimulating hormone (TSH) and free thyroxine (T(4)) related to pregnancy also confound the diagnosis of hypothyroidism during pregnancy. If the TSH is abnormal, then evaluation of free T(4) is recommended. The diagnosis of overt hypothyroidism is established by an elevated TSH and a low free T(4). The goal of treatment with levothyroxine is to return TSH to the normal range. Overt hyperthyroidism complicates approximately 2 of 1,000 pregnancies. Clinical features of hyperthyroidism can also be confused with those typical of pregnancy. Clinical hyperthyroidism is confirmed by a low TSH and elevation in free T(4) concentration. The goal of treatment with thioamide drugs is to maintain free T(4) in the upper normal range using the lowest possible dosage. Postpartum thyroiditis requiring thyroxine replacement has been reported in 2% to 5% of women. Most women will return to the euthyroid state within 12 months.

Interleukin-12B gene polymorphism does not confer susceptibility to Graves' ophthalmopathy in Japanese population

Graves' disease (GD) is an autoimmune disorder with genetic predisposition and frequently associated with Graves' ophthalmopathy (GO). Interleukin 12 (IL-12) is an important mediator of inflammatory immune responses and is expressed in the thyroid and orbit. IL-12B gene, which encodes the p40 subunit of IL-12, is located at chromosome 5q31-33. The aim of the present study was to investigate whether IL-12B gene polymorphism is associated with the development of GD or GO. IL-12B gene polymorphism was studied in Japanese GD patients (n = 329) and healthy control subjects without anti-thyroid autoantibodies or a family history of autoimmune disorders (n = 226). The A/C polymorphism at position 1188 of the 3' untranslated region (3'UTR) of the IL-12B gene was analyzed using the polymerase chain reaction--restriction fragment length polymorphism method. There was no difference in allele or genotype frequency of the IL-12B gene polymorphism (1188A/C) between GD patients and control subjects. There was no association of the IL-12B gene polymorphism with ophthalmopathy, severity of hyperthyroidism or serum IgE levels. There was no association of the IL-12B gene polymorphism with serum IL-12 levels, which were significantly elevated in hyperthyroid phase of GD. In conclusion, IL-12B gene 1188A/C polymorphism is not associated with GD or GO susceptibility in Japanese.

Thyroidectomy for Graves' Disease: A Case-Control Study

Objectives:

The most common treatment for Graves' disease in the United States is radioactive iodine. Surgery is performed rarely. The surgery for Graves' disease is usually considered technically difficult. Our goal was to assess the differences in outcomes in patients with Graves' disease who underwent thyroidectomy and in patients without Graves' disease who underwent the same procedures.

Methods:

A retrospective chart review was performed of patients who underwent surgery for Graves' disease between 1997 and 2005. A control group of age-matched and thyroid size-matched patients who underwent thyroidectomy for a diagnosis other than Graves' disease was identified. The groups were statistically compared with respect to length of hospital stay, operative time, and estimated blood loss. Comparison with the published literature was also performed.

Results:

Eleven patients underwent thyroidectomy for a diagnosis of Graves' disease. The operative time, estimated blood loss, and length of hospitalization did not differ significantly from those of the control patients. Three of the 4 complications that occurred, however, were in the 3 patients with persistent hyperthyroidism despite medical therapy at the time of surgery.

Conclusions:

Thyroidectomy may be performed relatively safely for selected euthyroid patients with Graves' disease. In those with persistent hyperthyroidism at surgery, there were more complications.

Dysregulation of TNF/TNFR superfamily members: a systemic link between intra- and extrathyroidal manifestations in Graves' disease

Graves' disease (GD) coincides with the occurrence of disease-associated intrathyroidal dendritic cells (DC) and intraorbital inflammatory macrophages (Mphi). Physiologically, tumour necrosis factor-alpha (TNF-alpha) strongly affects the differentiation of DC and Mphi from monocytic precursors; we thus hypothesized that dysregulation of the TNF/TNFR superfamilies may provide a systemic pathogenic link in GD. In patients without eye symptoms, percentages of TNF-alpha-stimulated blood monocytes were highly significantly (P < 0.001) elevated, corresponding to both intrathyroidal DC maturation as well as increases in mature blood DC (MHC-II(hi)/CD40+/RFD1(hi)) and B cells (CD20(hi)/CD40+). GD patients also displaying eye symptoms revealed a striking reduction in blood monocytes, yet significantly (P < 0.05) increased CD40(hi) and TNF-alpha(hi) leucocytes. These findings suggest for GD that excess TNF-alpha induces monocytes to differentiate into hyperactivated thyroidal DC that, once emigrated, initiate systemic humoral autoimmunity associated with CD40/TNF-alpha upregulation. Such overexpression may instigate differentiation of periorbital inflammatory Mphi from CD14(hi)/CD16+ monocytes as a likely precursor subset. These results indicate that dysregulation of TNF/TNFR superfamily members provides a systemic pathogenic link in GD in that hyperactivated circulating monocytic precursors give rise to locally restricted, disease-associated DC and Mphi. Monocytes, therefore, may serve as a suitable target to therapeutically address the common precursor of key promoters of GD.

Spontaneous Hypothyroidism in the Follow up of Graves Hyperthyroid Patients Treated with Antithyroid Drugs

AIM

Spontaneous hypothyroidism may follow the natural course of Graves disease (GD) after treatment with antithyroid drugs (ATD).

METHODS

We studied retrospectively 139 remitted Graves hyperthyroid patients treated with ATD, with a follow-up period of 17.5 years (range 6 to 25 years). Elevated serum concentration of thyroid-stimulating hormone and low serum thyroxine concentrations confirmed the diagnosis.

RESULTS

Thirteen patients (median age, 41 years; 26 to 48 years) developed spontaneous hypothyroidism, 4 to 144 months (median, 48 months ) following withdrawal of ATD. The prevalence of hypothyroidism was 9.3% and the incidence was 2.3% per year (13/ 563.6 patients/year of observation). There was no association with types of drugs used or the regimens. Spontaneous hypothyroid patients showed elevated titers (P = 0.02) of serum antithyroid peroxidase antibody (TPOAb) at the end of treatment with ATD, compared with the titers found at the beginning. These patients also had higher titers of TPOAb (P = 0.01) in relation to euthyroid patients. In contrast, the changes in serum antithyroglobulin antibody titers were not significant.

CONCLUSIONS

Because of the shift from euthyroidism to spontaneous hypothyroidism, GD patients demanded a strict follow up after ATD therapy. It seems that there is an effect of TPOAb on thyroid destruction.

Differential evolution of thyroid peroxidase and thyrotropin receptor antibodies in Graves' disease: thyroid peroxidase antibody activity reverts to pretreatment level after carbimazole withdrawal

In this study, we compared the evolution of thyroid peroxidase antibody (TPOAb) and thyroid-stimulating antibody (TSAb) activities before, during, and after treatment of Graves' disease (GD) with carbimazole. TPOAb and TSAb were measured in sera from 75 patients with GD, during an 18-month block-replace regimen and after drug withdrawal (12, 24, and 36 months). At diagnosis, TPOAb were present in 85% of the patients versus 99% for TSAb. During the treatment, TPOAb values and prevalence significantly decreased, as observed with TSAb. After drug withdrawal, TPOAb levels increased once again to reach the pretreatment values, whereas TSAb remained unchanged. TPOAb values and prevalence at drug withdrawal were not significantly different between patients who remained euthyroid and those who had a relapse of hyperthyroidism. In contrast, TSAb values and prevalence were higher at drug withdrawal in relapse patients. In conclusion, TPOAb and TSAb changes are similar during GD treatment by carbimazole but diverge after drug withdrawal. TPOAb might reflect autoimmune perturbations independently of the clinical status and of the thyroid-stimulating activity.

Subtotal Thyroidectomy: A Reliable Method to Achieve Euthyroidism in Graves’ Disease. Prognostic Factors

BACKGROUND

Subtotal thyroidectomy is a widely accepted surgical procedure for Graves' disease. The purpose of this work is to evaluate functional long-term results and determine predictive prognostic factors of postoperative thyroid function.

STUDY DESIGN

This is a retrospective study conducted on 202 patients with Graves' disease undergoing subtotal thyroidectomy during the period 1979-2002. Predictive prognostic factors of final thyroid status were investigated by logistic ordinal regression, and probability of hypothyroidism during the years of follow-up was obtained by the Kaplan-Meier method.

RESULTS

Surgery controlled hyperthyroidism in 196 out of 202 patients (97%). The probability of hypo-, eu-, and hyperthyroidism at 5 years was 62.1%, 35.5%, and 2.4%, respectively. No statistical change in thyroid function occurred in the follow-up after 60 months. Multivariate analysis by a logistic ordinal regression analysis showed that weight of the remnant, age, and gender seemed to influence long-term thyroid function. The higher rates of euthyroidism were obtained when the remnant weight was between 6 and 8 g. No recurrence or persistence of hyperthyroidism occurred with remnant weights under 5 g.

CONCLUSIONS

Subtotal thyroidectomy controlled hyperfunction symptoms in 97% of our patients. Cure (euthyroidism) of Graves' disease patients should be attempted by leaving a thyroid tissue remnant between 6 and 8 g. Even more significant, our results suggest that euthyroidism rates could be improved by leaving a smaller remnant in elderly women and greater remnants in young men.

Pharmacokinetics and Pharmacotherapy of Thionamides in Pregnancy

Hyperthyroidism occurs in approximately 1 in every 1000 to 2000 pregnancies. Although the signs and symptoms of the disease are similar in the pregnant and nonpregnant patient, the complications of hyperthyroidism can have even more profound consequences for the mother and fetus during gestation. These include maternal heart failure, preeclampsia, miscarriage, and preterm labor; as well as fetal loss and low birth weight. Furthermore, thyroid function and laboratory testing for hyperthyroidism are altered in pregnancy. The gestational increase in thyroid size, increased thyroid-binding globulin levels, increased serum total T4 and total T3 levels, and decreased thyroid stimulating hormone levels often confuses the evaluation of the thyroid status in pregnancy. Worldwide, the thionamides-propylthiouracil, methimazole, and carbimazole-have been used in pregnancy for the treatment of hyperthyroidism. However, propylthiouracil has been the drug of choice in the United States because it is believed to have less potential to induce fetal/neonatal hypothyrodism, to cross the placenta and into breast milk to a lesser degree, and to be less teratogenic than methimazole or carbimazole. None of the above have been substantiated in more recent studies. The pharmacokinetics of the thionamides in the pregnant and nonpregnant states, as well as the pharmacotherapeutic recommendation for hyperthyroidism will be reviewed.

Resistance Training Improves Muscle Function and Body Composition in Patients With Hyperthyroidism

OBJECTIVE

To evaluate the effect of resistance training on skeletal muscle performance and body composition in patients with medically treated hyperthyroidism.

DESIGN

Nonrandomized controlled trial.

SETTING

Large public tertiary hospital.

PARTICIPANTS

Sixteen sedentary patients with recent clinical diagnosis and laboratory confirmation of hyperthyroidism (7 men, 9 women; age, 38+/-11 y; weight, 58.4+/-2.6 kg; height, 1.6+/-0.3m) were assigned to the control group (medical therapy; n=9) or training group (medical therapy associated with resistance training; n=7). An age- and sex-matched healthy group served as controls (3 men, 5 women; age, 40+/-3 y; weight, 68.4+/-4.3 kg; height, 1.6+/-0.3m).

INTERVENTION

Resistance training twice a week for 16 weeks.

MAIN OUTCOME MEASURES

Peak muscular strength (by dynamometry and 1 repetition maximum method) and endurance (30% of peak force) for 7 movements and anthropometric measurements.

RESULTS

The hyperthyroid patients as a group had lower baseline overall strength values when compared with healthy subjects (200.3+/-16.0 kg vs 274.9+/-21.8 kg, respectively; P=.006). Overall absolute increases in strength (49 kg vs 91 kg, P<.05) and endurance (78.5x10(2)kg/s vs 176.9x10(2)kg/s, P<.05) were higher in the training group compared with the control group. Body weight increased in both groups, but the sum of muscular circumference increased only in the training group (training group, 92.6+/-3.3 cm vs 97.1+/-3.8 cm; control group, 94.6+/-2.2 cm vs 94.4+/-2.1cm; P<.05), with no change in the sum of skinfolds.

CONCLUSIONS

Resistance training accelerates the recovery of skeletal muscle function and promotes weight gain based on muscle mass improvement in patients with medically treated hyperthyroidism.

Resistin levels are normal in hypothyroidism and remain unchanged after attainment of euthyroidism: relationship with insulin levels and anthropometric parameters

The aim of this controlled prospective study was to investigate resistin levels in hypothyroidism before and after restoration of euthyroidism and correlate the results with body weight (BW), body fat (BF), waist circumference (WC), body mass index (BMI) and serum insulin levels. Fifty-three hypothyroid patients with Hashimoto's disease (6 males, 47 females) and 30 controls matched for age, BMI and BF were investigated. Anthropometric parameters, resistin and insulin levels were measured. All patients were started on levothyroxine treatment and 4 to 5 months after initiation of treatment the investigations were repeated. Hypothyroid patients exhibited normal resistin values, which were no different from controls (mean+/-SD 7.4+/-4.0 vs 5.1+/-3.5 ng/ml, p=0.063). Normalization of circulating thyroid hormone levels produced no significant change in resistin levels (7.4+/-4.0 vs 6.8+/-4.2 ng/ml, p=ns) and post-treatment resistin levels did not differ from euthyroid controls. Furthermore, no gender difference was demonstrated in resistin levels either before (6.4+/-3.7 for males vs 7.6+/-4.1 ng/ml for females, p=ns) or after therapy (7.9+/-4.3 vs 6.7+/-4.3 ng/ml, for males and females respectively, p=ns), nor was there a difference in resistin levels in either sex induced by treatment of hypothyroidism (6.4+/-3.7 vs 7.9+/-4.3 ng/ml for males, p=ns, and 7.6+/-4.1 vs 6.7+/-4.3 ng/ml for females, p=ns). However, a small but significant difference in resistin levels was found between female patients and female controls (7.6+/-4.1 vs 5.0+/-4.0 ng/ml, p=0.047). Insulin levels and homeostasis model assessment insulin resistance (HOMA-IR) index did not differ before and after treatment in hypothyroid patients (13.0+/-10.2 vs 12.6+/-11.8 microU/ml, 22.7+/-1.4 vs 21.8+/-1.3, respectively, p=ns for both) or between patients and controls. In conclusion, our results demonstrate that resistin levels are normal in hypothyroidism and remain within normal range after attainment of euthyroidism. Resistin is not associated with serum insulin and HOMA-IR index, as well as BMI, BF, WC and BW.

Antibodies targeting the calcium binding skeletal muscle protein calsequestrin are specific markers of ophthalmopathy and sensitive indicators of ocular myopathy in patients with Graves' disease

We have identified several eye muscle antigens and studied the significance of the corresponding serum autoantibodies in patients with Graves' disease. Of these antigens, only calsequestrin is expressed more in eye muscle than other skeletal muscles, which could explain at least partly the specific involvement of eye muscle in patients with Graves' disease. Earlier, we found a modest relationship between anti-calsequestrin antibodies and ophthalmopathy, but in that study we used calsequestrin prepared from rabbit heart muscle and measured antibodies by immunoblotting. We have reinvestigated the prevalences of anti-calsequestrin antibodies in larger groups of well-characterized patients with thyroid autoimmunity with and without ophthalmopathy and control patients and healthy subjects, using standard enzyme-linked immunosorbent assay incorporating highly purified rabbit skeletal muscle calsequestrin, which has a 97% homology with human calsequestrin, as antigen. Anti-calsequestrin antibodies were detected in 78% of patients with active congestive ophthalmopathy, in 92% of those with active inflammation and eye muscle involvement, but in only 22% of patients with chronic, 'burnt out' disease. Tests were also positive in 5% of patients with Graves' hyperthyroidism without evident ophthalmopathy (two patients) and one patient with 'watery eyes' but no other clear signs of congestive ophthalmopathy and IgA nephropathy and no known thyroid disease, but in no patient with Hashimoto's thyroiditis, toxic nodular goitre, non-toxic multi-nodular goitre or diabetes, or age- and sex-matched healthy subjects. In serial studies of all 11 patients with Graves' hyperthyroidism who had active ophthalmopathy at the time of the first clinic visit, or developed eye signs during the first 6 months, and positive anti-calsequestrin antibodies in at least one sample, anti-calsequestrin antibodies correlated with the onset of ocular myopathy in six patients. Antibodies targeting calsequestrin appear to be specific markers for ophthalmopathy and sensitive indicators of the ocular myopathy subtype of ophthalmopathy in patients with thyroid autoimmunity. However, these results must be considered preliminary until a large prospective study of patients with newly diagnosed Graves' hyperthyroidism, in which serum levels of calsequestrin antibodies are correlated with clinical changes and orbital eye muscle and connective tissue/fat volumes, has been carried out.

Profound reduction in T-helper (Th) 1 lymphocytes in peripheral blood from patients with concurrent type 1 diabetes and Graves' disease

Type 1 diabetes likely is mediated by T-helper (Th) 1 lymphocytes, while Graves' disease may involve Th2 predominance. We investigated the balance between Th1 and Th2 cells and between Th1- and Th2-associated chemokine receptor expression on peripheral lymphocytes in subjects including patients with coexisting type 1 diabetes and Graves' disease. Peripheral blood mononuclear cells of all subjects were examined by flow cytometry for intracellular cytokines (IFN-gamma for Th1; IL-4 for Th2) and expression of the chemokine receptors CXCR3 (Th1-associated) and CCR4 (Th2-associated). Plasma concentrations of interferon-inducible protein (IP)-10, a CXCR3 ligand, and thymus and activation-regulated chemokine (TARC), a CCR4 ligand, were measured by enzyme-linked immunosorbent assays. IFN-gamma producing-T lymphocytes were significantly fewer in patients with coexisting type 1 diabetes and Graves' disease (12.4 +/- 6.8%, n = 6) than in healthy control subjects (19.9 +/- 4.1%, n = 6; P < 0.01) or patients with type 2 diabetes (19.1 +/- 4.5%, n = 5; P < 0.05). We found no significant difference in IFN-gamma-producing T lymphocytes between healthy controls and patients with only type 1 diabetes (n = 8) or Graves' disease (n = 5). Plasma IP-10 concentrations were significantly higher in patients with coexisting type 1 diabetes and Graves' disease than in control subjects (106.3 +/- 30.48 vs. 66.7 +/- 25.3 pg/ml, P = 0.0343). Considering only patients with type 1 diabetes alone, duration of diabetes correlated positively with IFN-gamma-producing T lymphocytes (r = 0.773, P = 0.0242) and the ratio of CXCR3 to CCR4 receptor expression (r = 0.947, P = 0.0004). In conclusion, Th1-associated T lymphocytes were fewer in peripheral blood from patients having both type 1 diabetes and Graves' disease than in those with either disease alone. Numbers of peripheral Th1 lymphocytes increased with increasing time from onset of type 1 diabetes in patients with type 1 diabetes alone.

Extensive Thyroidectomy in Graves’ Disease

BACKGROUND

The best surgical treatment for hyperthyroidism caused by Graves' disease remains a controversial subject.

METHODS

Seven hundred fourteen consecutive patients underwent total or near-total thyroidectomy for Graves' disease in a 13-year period. In a first analysis, postoperative rates of suffocating hematoma, wound infection, recurrent laryngeal nerve (RLN) palsy, hypoparathyroidism, and persistence or recurrence of hyperthyroidism, were studied and compared with the same parameters in 4,426 patients who underwent bilateral thyroid gland resection for other conditions. A second analysis identified factors associated with postoperative complications among Graves' disease patients.

RESULTS

Comparing Graves' disease patients with patients who had bilateral thyroid resection for other conditions, the transient morbidity rate was 13.3% versus 8.2% (p < 0.0001), with 10.2% versus 5.0% (p < 0.0001) hypoparathyroidism, 2.2% versus 1.7% (p = 0.35) RLN palsy, 1.7% versus 0.9% (p < 0.05) suffocating hematoma, and 0.3% versus 0.4% (p = 0.67) wound infection, respectively. Permanent morbidity rate was 2% versus 2.2% (p = 0.72), including 0.4% versus 0.6% RLN palsy and 1.5% versus 1.7% hypoparathyroidism. Among the Graves' disease patients, univariate analysis revealed that those who experienced postoperative complications had a higher weight resected thyroid gland (odds ratio = 1.5; 95% CI, 1.0-2.3) and a higher rate of total thyroidectomy (24.4% versus 19.5%, odds ratio = 2.2; 95% CI, 1.4-3.4) than patients without complications. In the multivariable model, these two factors remained independent. There was no recurrence of hyperthyroidism with a median followup of 6.7 years (interquartile range 4.1 to 10.1 years). Persistent hyperthyroidism developed in three patients.

CONCLUSIONS

Total or near-total thyroidectomy is an effective and safe treatment for Graves' disease when performed by an experienced surgeon.

The clinical and physiological spectrum of interferon-alpha induced thyroiditis: toward a new classification

Interferon-alpha (IFNalpha) is a major treatment modality for several malignant and nonmalignant diseases, especially hepatitis C. Prospective studies have shown that up to 15% of patients with hepatitis C receiving IFNalpha develop clinical thyroid disease, and up to 40% were reported to develop thyroid antibodies. Some of these complications may result in discontinuation of interferon therapy. Thus, interferon induced thyroiditis (IIT) is a major clinical problem for patients receiving interferon therapy. IIT can be classified as autoimmune type and non-autoimmune type. Autoimmune IIT may manifest by the development of thyroid antibodies without clinical disease, or by clinical disease which includes both autoimmune hypothyroidism (Hashimoto's thyroiditis) and autoimmune thyrotoxicosis (Graves' disease). Non-autoimmune IIT can manifest as destructive thyroiditis or as hypothyroidism with negative thyroid antibodies. Early detection and therapy of these conditions is important in order to avoid complications of thyroid disease such as cardiac arrhythmias. While it is not clear which factors contribute to the susceptibility to IIT, recent evidence suggests that genetic factors, gender, and hepatitis C virus infection may play a role. In contrast, viral genotype and therapeutic regimen do not influence susceptibility to IIT. The etiology of IIT is unknown and may be secondary to immune modulation by IFNalpha and/or direct effects of interferon on the thyroid. In this review we discuss the clinical and pathophysiological aspects of IIT, and we are proposing a new, etiology-based classification of IIT, as well as an algorithm for diagnosis and treatment of IIT.

Thyroid disorders. Part I: hyperthyroidism

The significant thyroid disorders that may be found in dental patients are presented in a series of 3 articles. This article (part I) deals with hyperthyroidism, part II with hypothyroidism and thyroiditis, and part III with neoplastic lesions of the thyroid. The signs and symptoms, laboratory tests used to diagnoses hyperthyroidism, and the medical management of patients with hyperthyroidism are presented in this paper. The dental management of patients with hyperthyroidism is discussed in detail. The dentist, by detecting the early signs and symptoms of hyperthyroidism, can refer the patient for medical diagnosis and treatment and avoid potential complications of treating patients with uncontrolled disease. These complications include the rare thyrotoxic crisis (thyroid storm) that may be precipitated by dental treatment, acute infection, or trauma in the patient with uncontrolled hyperthyroidism. Also, the use of epinephrine or other pressor ammines can cause a hypertensive crisis in the patient with uncontrolled hyperthyroidism. Patients will benefit from the early detection and referral by reducing the risks of the medical complications such as hypertension, cardiac arrhythmias, and congestive heart failure.

Serum thyrotropin receptor antibodies concentrations in patients with Graves' disease before, at the end of methimazole treatment, and after drug withdrawal: evidence that the activity of thyrotropin receptor antibody and/or thyroid response modify during the observation period

AIM AND METHODS

We performed a quantitative retrospective analysis of serum thyrotropin receptor antibody (TRAb) concentrations measured by a second-generation radioreceptor assay in 58 patients with Graves' disease (GD) at the onset of the disease, at the end of 18 month methimazole (MMI) treatment, and after MMI withdrawal in order to evaluate the correlation between the presence of these antibodies and the relapse of hyperthyroidism. Sixty healthy subjects were enrolled as a control group.

RESULTS

Before MMI treatment the best cutoff TRAb value for identifying patients with GD was 1.45 UI/L (specificity, 100%; sensitivity, 98.3%). At the end of MMI treatment, serum TRAb concentrations were significantly lower (p < 0.001) than those measured at baseline, but they were still significantly higher (p < 0.001) than those found in the control subjects. At the end of MMI treatment, 44 patients (75.9%) had positive TRAb values (>1.45 UI/L). After MMI withdrawal (median, 15 months), 34 patients (58.6%) became hyperthyroid, 4 patients (6.9%) became hypothyroid, and 20 patients (34.5%) remained euthyroid. There was a significant correlation between serum TRAb concentrations at the end of MMI treatment and the percentage of patients who became hyperthyroid (r: 0.56; p < 0.001) and the time of appearance of hyperthyroidism (r: -0.38; p = 0.03). All 4 patients with TRAb values below 0.9 UI/L at the end of MMI treatment remained euthyroid throughout the follow-up period. Among the 27 patients who had serum TRAb values higher than 4.4 UI/L, 23 developed hyperthyroidism and 4 hypothyroidism. The TRAb values between 0.9 and 4.4 UI/L did not discriminate between the 27 patients (46.6%) who remained euthyroid from those who had relapse of hyperthyroidism. Thus a different TRAb end of treatment cutoff was calculated to identify patients who became again hyperthyroid. This TRAb cutoff value was 3.85 UI/L (sensitivity, 85.3%; specificity, 96.5%). All but 1 patient who had serum TRAb values above 3.85 UI/L became hyperthyroid after MMI was withdrawn (positive predictive value, 96.7%). In these patients, relapse of hyperthyroidism was independent of the changes in serum TRAb concentrations (r: 0.27; p = 0.15) and occurred after a median period of 8 weeks (range, 4-48). Hyperthyroidism also developed in 5 of 24 patients who had serum TRAb concentrations lower than 3.85 UI/L at the end of MMI treatment. In these 5 patients the relapse of hyperthyroidism occurred after a median period of 56 weeks (range, 24-120) and was always accompanied by an increase in serum TRAb concentrations.

CONCLUSIONS

TRAb persist in the blood of most patients with GD after 18 months of MMI treatment. Both the frequency and the time of appearance of hyperthyroidism are closely correlated with serum TRAb concentrations at the end of MMI treatment. Our data would suggest that TRAb maintain stimulating activity after a full course of MMI treatment in the large majority of patients with GD. However, it is likely that the potency of these antibodies and/or the thyroid response to them change during treatment, as suggested by the different values measured in euthyroid control subjects and in euthyroid patients after MMI treatment.

Lack of association of interleukin-18 gene polymorphisms with susceptibility of Japanese populations to Graves' disease or Graves' ophthalmopathy

OBJECTIVE

To investigate whether polymorphisms of interleukin (IL)-18 gene confer susceptibility to Graves' disease (GD) and Graves' ophthalmopathy (GO).

DESIGN

We performed a case control study on polymorphisms of IL-18 gene in Japanese patients with GD (n = 435), and healthy control subjects without antithyroid autoantibodies or family history of autoimmune disorders (n = 255). The C-4675G, C-607A, and G-137C polymorphisms in the promoter region and A105C (exon 5) polymorphism were determined by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) using restriction enzymes, sequence-specific PCR, and PCR-direct sequencing methods.

RESULTS

None of the polymorphisms in the IL-18 gene were associated with development of Graves' disease. The CC genotype and C allele frequencies of IL-18 gene G-137C polymorphism tended to be greater in patients with ophthalmopathy than in patients without evident ophthalmopathy. However, the differences were not statistically significant. Although there were three major haplotypes, none of the haplotypes were statistically associated with susceptibility to GD or ophthalmopathy.

CONCLUSIONS

These results suggest that IL-18 gene polymorphisms are not major genetic factors for susceptibility to GD in a Japanese population. Further studies with adequate sized data set in the subset analyses for GO are needed.

The surgical management of Graves' disease

BACKGROUND

The historical aspects of the pathophysiology and treatment of Graves' disease are briefly discussed in this paper.

MATERIALS AND METHODS

The three treatment modalities of Graves' disease are anti-thyroid drug therapy, radioactive iodine therapy, and surgery. Although the majority of patients with Graves' disease in the U.S. are treated with radioactive iodine, surgery still plays an important role when patients cannot tolerate anti-thyroid drug therapy, when medical treatment is rejected by patients, or when surgery is deemed the fastest and safest route in managing the patient.

CONCLUSIONS

The indications for surgical management of Graves' disease are discussed with emphasis on available data supporting the extent of thyroid resection based on the incidences of hypothyroidism, recurrence of hyperthyroidism, recurrent laryngeal nerve injury and hypoparathyroidism.

Hypothesis: Dietary Iodine Intake in the Etiology of Cardiovascular Disease

This paper reviews evidence suggesting that iodine deficiency can have deleterious effects on the cardiovascular system, and correspondingly, that a higher iodine intake may benefit cardiovascular function. In recent years, public health bodies have aggressively promoted sodium restriction as a means of reducing hypertension and the risk of cardiovascular disease. These inducements have led to a general decline in iodine intake in many developed countries. For example, a United States national health survey conducted in the early 1970s observed that 1 in 40 individuals had urinary iodine levels suggestive of moderate or greater iodine deficiency; twenty years later, moderate to severe iodine deficiency was observed in 1 in 9 participants. Regional iodine intake has been shown to be associated with the prevalence of hypothyroidism and hyperthyroidism, where autoimmune hypothyroidism is the more common of the two in regions with moderate to high iodine intake. Both of these thyroid abnormalities have been shown to negatively affect cardiovascular function. Selenium, an important antioxidant in the thyroid and involved in the metabolism of iodine-containing thyroid hormones, may play an interactive role in the development of these thyroid irregularities, and in turn, cardiovascular disease. Iodine and iodine-rich foods have long been used as a treatment for hypertension and cardiovascular disease; yet, modern randomized studies examining the effects of iodine on cardiovascular disease have not been carried out. The time has come for investigations of sodium, hypertension, and cardiovascular disease to also consider the adverse effects that may result from mild or greater iodine deficiency.

Upper airway compromise secondary to edema in Graves’ disease

PURPOSE

We report an unusual case of upper airway compromise in a patient with Graves' disease. We speculate that this complication may be due, in part, to poorly controlled hyperthyroidism.

CLINICAL FEATURES

A 26-yr-old female suffering from Graves' disease underwent a total thyroidectomy. Awake fibreoptic intubation was attempted because of a large goiter and orthopnea. Upper airway edema impeded the passage of an armored 7.5 mm endotracheal tube. She was subsequently intubated awake with a regular 7.5 mm endotracheal tube under direct laryngoscopy over an Eschmann bougie. The patient was extubated in the operating room over a tube exchanger. Two hours later she developed stridor and upper airway obstruction. Using direct laryngoscopy, she was reintubated with difficulty because of upper airway edema. At this time, she manifested signs of thyrotoxicosis which were managed medically. On postoperative day three she underwent a tracheostomy after failing a trial of extubation. The upper airway was edematous with minimal vocal cord movement. On postoperative day nine the tracheostomy was downsized and the patient was sent home. The vocal cords were still edematous with minimal movement. Three weeks later, she demonstrated normal right vocal cord movement and weak left vocal cord movement, and the tracheostomy was decannulated.

CONCLUSIONS

Uncontrolled hyperthyroid patients with large goiters secondary to Graves' disease may develop edema of the upper airway. A high degree of vigilance for airway obstruction is necessary, with a carefully planned approach at each stage of the patient's hospital course to treat this potentially life-threatening situation.

Association of the TSHR gene with Graves' disease: the first disease specific locus

The development of autoimmune thyroid disease (AITD) is associated with autoantibodies directed against the thyroid stimulating hormone receptor (TSHR). Previous studies have failed to demonstrate a consistent association between the TSHR and AITD, or any of its sub-phenotypes. In the present study, we analysed the linkage disequilibrium (LD) structure encompassing the TSHR, to identify LD 'blocks' and SNPs, which capture the majority of intra-block haplotype diversity. The haplotype tagging SNPs, plus all common SNPs reported in previous studies were genotyped in 1,059 AITD Caucasian cases and 971 Caucasian controls. A haplotype, across two LD blocks, showed association (P<1 x 10(-6), OR 1.7) with Graves' disease (GD) but not autoimmune hypothyroidism (AIH). We replicated these findings by genotyping the most associated GD SNP, rs2268458, in a separate UK Caucasian cohort of 1,366 AITD cases and 1,061 controls (GD, P=2 x 10(-6), OR 1.3; AIH, P=NS). These results in two independent Caucasian data sets suggest that the TSHR is the first replicated GD-specific locus meriting further fine mapping and functional analysis to identify the aetiological variants.

Dysphagia as a primary manifestation of hyperthyroidism: a case report

Myopathy effecting mainly skeletal muscles of the limbs are frequently seen in hyperthyroidism. Rarely bulbar muscles may also be involved, causing dysphagia, nasal speech, and aspiration. We report a 70-year-old woman with severe dysphagia and aspiration pneumonia. Clinical examination and laboratory tests showed an underlying Graves' disease. Her dysphagia improved dramatically by antithyroid therapy. Considering its excellent response to medical therapy, hyperthyroidism--being a very rare factor - is well-worth to remember for the unexplained dysphagia cases.

Assisting the Diagnosis of Thyroid Diseases with Bayesian-Type and SOM-Type Neural Networks Making Use of Routine Test Data

Patients with hyperthyroidism sometimes take much time to receive the final diagnosis. To improve patient QOL, simple screening for hyperthyroidism by thyroid non-specialists at the physical check-up is highly expected. Therefore, we applied both Bayesian-type and SOM-type neural networks since we assured the approach useful in analysing thyroid function diagnosis in the previous work. Routine test (14 parameters) data from 66 subjects with a known diagnosis (18 patients with hyperthyroidism and 48 healthy volunteers) were adopted as learning data, and then 142 individuals who also received the same routine tests at the Tohoku University Hospital were screened to predict patients with hyperthyroidism. Both neural networks using 14 parameters predicted several patients as having hyperthyroidism with high probability, including all three hyperthyroid patients diagnosed later by the physician. Further detailed analysis of the routine test parameters that were important for classification found that screening with a set of three parameters (alkaline phosphatase, serum creatinine and total cholesterol) or plus aspartate aminotransferase allowed for quite accurate screening. These results showed that the same neural networks as previous work allows simple screening of patients for hyperthyroidism on the basis of routine test data, and that physicians not specializing in the thyroid can rapidly identify individuals suspected of having hyperthyroidism, to permit a rapid referral for examination and treatment by thyroid specialists.

A 40-year-old woman who developed jaundice during therapy for thyrotoxicosis

Ekpebegh and Levitt discuss the differential diagnosis of jaundice in patients with thyrotoxicosis.

New insights into antibody-mediated hyperthyroidism

The most common cause of hyperthyroidism is Graves' disease, which represents a typical example of an organ-specific autoimmune condition. The exact triggers for the disease remain unknown, but are likely to involve a complex interaction between multiple environmental factors in a genetically predisposed individual. The main feature of the condition is the presence of thyroid-stimulating antibodies, which activate the thyroid- stimulating hormone receptor, resulting in hyperthyroidism. These antibodies may also be involved in the extrathyroidal complications of the disease. The recent generation of thyroid-stimulating antibodies in animal models and the isolation of monoclonal thyroid-stimulating antibodies from a patient with Graves' disease should allow the detailed study of thyroid-stimulating antibodies-thyroid-stimulating hormone receptor interactions. This will help to shed more light on disease pathogenesis and may offer new treatment strategies in difficult cases, particularly in patients with extrathyroidal complications.

Thyrotoxicosis and pregnancy

A 35-year-old woman presented with a neck swelling after a missed abortion. Her thyroid function tests were in the thyrotoxic range. Perros discusses the further investigation and management of this patient.

Elevation of serum adiponectin levels in Basedow disease

The present study was undertaken to determine whether thyroid hormone affects serum adiponectin levels in the patients with Basedow disease. Sixty-four patients with Basedow disease were examined; 32 patients had hyperthyroid state and 32 patients had euthyroid state who had been treated with antithyroid drugs. In addition, 30 age- and sex-matched subjects served as a control. Serum adiponectin, free T4, free T3, thyroid-stimulating hormone, and thyroid-stimulating hormone receptor antibody (TRAb) were measured. Serum adiponectin levels were 12.9+/-1.6 microg/mL in the hyperthyroid state, a value significantly greater than that of 8.2 +/- 0.5 microg/mL in the euthyroid state (P<.05) and that of 8.6+/-0.7 microg/mL in the control subjects (P<.05). Serum adiponectin levels had positive correlations with either of serum free T4 (r=0.453, P<.001), free T3 (r=0.47, P< .001), or TRAb (r= 0.491, P<.001), but not with body mass index. Multiple regression analysis showed TRAb had the strongest contribution to serum adiponectin concentration in the patients with Basedow disease. The present findings indicate that hyper-adiponectinemia is closely associated with increases in serum thyroid hormone levels and TRAb in Basedow disease.

Thyroid function during pregnancy in women with past Graves' disease

Graves' disease and thyroid dysfunction during pregnancy can lead to maternal and fetal complications. No information is available on thyroid function in women with a past history of Graves' disease. We compared free T3, free T4 and TSH in a group of pregnant women with a history of resolved Graves' disease requiring no current treatment (n= 34) and in a group of pregnant controls (n= 102). We found no significant differences in the levels of these hormones between the two groups. Women with a past history of Graves' disease and no current treatment display a normal thyroid function and adaptation during pregnancy.

Management of Graves' disease during pregnancy: the key role of fetal thyroid gland monitoring

BACKGROUND

Fetuses from mothers with Graves' disease may experience hypothyroidism or hyperthyroidism due to transplacental transfer of antithyroid drugs (ATD) or anti-TSH receptor antibodies, respectively. Little is known about the fetal consequences. Early diagnosis is essential to successful management. We investigated a new approach to the fetal diagnosis of thyroid dysfunction and validated the usefulness of fetal thyroid ultrasonograms.

METHODS

Seventy-two mothers with past or present Graves' disease and their fetuses were monitored monthly from 22 wk gestation. Fetal thyroid size and Doppler signals, and fetal bone maturation were determined on ultrasonograms, and thyroid function was evaluated at birth. Thyroid function and ATD dosage were monitored in the mothers.

RESULTS

The 31 fetuses whose mothers were anti-TSH receptor antibody negative and took no ATDs during late pregnancy had normal test results. Of the 41 other fetuses, 30 had normal test results at 32 wk, 29 were euthyroid at birth, and one had moderate hypothyroidism on cord blood tests. In the remaining 11 fetuses, goiter was visualized by ultrasonography at 32 wk, and fetal thyroid dysfunction was diagnosed and treated; there was one death, in a late referral, and 10 good outcomes with normal or slightly altered thyroid function at birth. The sensitivity and specificity of fetal thyroid ultrasound at 32 wk for the diagnosis of clinically relevant fetal thyroid dysfunction were 92 and 100%, respectively.

CONCLUSION

In pregnant women with past or current Graves' disease, ultrasonography of the fetal thyroid gland by an experienced ultrasonographer is an excellent diagnostic tool. This tool in conjunction with close teamwork among internists, endocrinologists, obstetricians, echographists, and pediatricians can ensure normal fetal thyroid function.