Incidence of hyperthyroidism in Sweden.

INTRODUCTION: The incidence of hyperthyroidism has been reported in various countries to be 23-93/100,000 inhabitants per year. This extended study has evaluated the incidence for ~40% of the Swedish population of 9 million inhabitants. Sweden is considered to be iodine sufficient country. METHODS: All patients including children, who were newly diagnosed with overt hyperthyroidism in the years 2003-2005, were prospectively registered in a multicenter study. The inclusion criteria are as follows: clinical symptoms and/or signs of hyperthyroidism with plasma TSH concentration below 0.2 mIE/l and increased plasma levels of free/total triiodothyronine and/or free/total thyroxine. Patients with relapse of hyperthyroidism or thyroiditis were not included. The diagnosis of Graves' disease (GD), toxic multinodular goiter (TMNG) and solitary toxic adenoma (STA), smoking, initial treatment, occurrence of thyroid-associated eye symptoms/signs, and demographic data were registered. RESULTS: A total of 2916 patients were diagnosed with de novo hyperthyroidism showing the total incidence of 27.6/100,000 inhabitants per year. The incidence of GD was 21.0/100,000 and toxic nodular goiter (TNG=STA+TMNG) occurred in 692 patients, corresponding to an annual incidence of 6.5/100,000. The incidence was higher in women compared with men (4.2:1). Seventy-five percent of the patients were diagnosed with GD, in whom thyroid-associated eye symptoms/signs occurred during diagnosis in every fifth patient. Geographical differences were observed. CONCLUSION: The incidence of hyperthyroidism in Sweden is in a lower range compared with international reports. Seventy-five percent of patients with hyperthyroidism had GD and 20% of them had thyroid-associated eye symptoms/signs during diagnosis. The observed geographical differences require further studies.

Thyroid-associated ophthalmopathy; quality of life follow-up of patients randomized to treatment with antithyroid drugs or radioiodine.

OBJECTIVE: The objective of this study was to investigate quality of life (QoL) in patients with Graves' disease treated with radioiodine or antithyroid drugs. DESIGN AND METHODS: The design of the study consists of an open, prospective, randomized multicenter trial between radioiodine and medical treatment. A total of 308 patients were included in the study group: 145 patients in the medical group and 163 patients in the radioiodine group. QoL was measured with a 36-item Short Form Health Status Survey questionnaire (SF-36) at six time points during the 48-month study period. RESULTS: Patient who developed or got worse of thyroid-associated ophthalmopathy (TAO) at any time point during the 4-year study period (TAO group) had lower QoL when no respect was paid to the mode of treatment. TAO occurred in 75 patients who had radioiodine treatment at some time point during the study period as compared with TAO in 40 medically treated patients (P<0.0009). Comparisons between the group of patients who have had TAO versus the group without TAO, in relation to treatments and time, showed significantly decreased QoL scores for the TAO groups at several time points during the study. In patients without TAO, there were no differences in QoL related to mode of treatment. CONCLUSIONS: The QoL in patients with Graves' ophthalmopathy was similar in radioiodine and medically treated patients, but patients who developed or had worsening of TAO had decreased QoL independent of mode of treatment. Furthermore, patients with TAO recovered physically within 1 year but it took twice as long for them to recover mentally.

Thyroid-associated ophthalmopathy after treatment for Graves' hyperthyroidism with antithyroid drugs or iodine-131.

CONTEXT: Previous randomized trials have suggested an association between radioiodine treatment for Graves' hyperthyroidism and thyroid-associated ophthalmopathy (TAO). OBJECTIVES: The aim of the study was to compare the occurrence of worsening or development of TAO in patients who were treated with radioiodine or antithyroid drugs. DESIGN: We conducted a randomized trial (TT 96) with a follow-up of 4 yr. PATIENTS, SETTING, AND INTERVENTION: Patients with a recent diagnosis of Graves' hyperthyroidism were randomized to treatment with iodine-131 (163 patients) or 18 months of medical treatment (150 patients). Early substitution with T(4) was given in both groups. MAIN OUTCOME MEASURE: Worsening or development of TAO was significantly more common in the iodine-131 treatment group (63 patients; 38.7%) compared with the medical treatment group (32 patients; 21.3%) (P < 0.001). RESULTS: The risk for de novo development of TAO was greater in patients treated with iodine-131 (53 patients) than with medical treatment (23 patients). However, worsening of TAO in the 41 patients who had ophthalmopathy already before the start of treatment was not more common in the radioiodine group (10 patients) than in the medical group (nine patients). Smoking was shown to influence the risk of worsening or development of TAO, and smokers treated with radioiodine had the overall highest risk for TAO. However, in the group of smokers, worsening or development of TAO was not significantly associated with the choice of treatment for hyperthyroidism. CONCLUSIONS: Radioiodine treatment is a significant risk factor for development of TAO in Graves' hyperthyroidism. Smokers run the highest risk for worsening or development of TAO irrespective of treatment modality.

Exploring the use of recombinant human TSH in the diagnosis of central hypothyroidism.

CONTEXT: The diagnosis of central hypothyroidism (CH) is often difficult to establish as serum TSH levels may be low, normal, or slightly increased. OBJECTIVE: To explore the use of recombinant human TSH (rhTSH) in the diagnosis of CH. DESIGN: Randomized single-blind clinical trial. SETTING: Outpatient clinic of a tertiary care referral center. INTERVENTION: A single intramuscular injection of 0.1 and 0.9 mg rhTSH in random order with 1-week interval. PARTICIPANTS: Eighteen adult patients with pituitary insufficiency and six healthy age-, sex-, and body mass index-matched controls. Six patients had untreated CH (newCH), six had treated CH (CH), and six patients were TSH sufficient (nonCH). Five weeks before TSH stimulation, levothyroxine was replaced with tri-iodothyronine (T(3)) for 4 weeks. One week before stimulation, treatment was withdrawn. MAIN OUTCOME MEASURES: Thyroid hormones and thyroglobulin (Tg) before and 2, 3(1/2), 7, 24, 48, and 72 h after each injection. RESULTS: In the newCH group, basal free thyroxine (FT(4)) levels were lower than in controls (P<0.05). After 0.9 mg rhTSH, the increases in FT(4) and reverse T(3) (rT(3)) were less marked in the newCH group than in controls (FT(4)+/-s.e.m. 9.2+/-0.5 to 19.7+/-1.2 vs 11.3+/-0.5 to 27.8.2+/-2.4 pmol/l, P<0.05). The CH group exhibited reduced basal and stimulated FT(4) compared with the TSH-sufficient groups. Tg increased similarly among all study groups after rhTSH injection. CONCLUSION: In this pilot study, patients with untreated CH had lower response to 0.9 mg rhTSH in FT(4) and rT(3) than controls. An rhTSH test may be useful in the diagnosis of CH, but further studies are required.

Consequences of inadvertent radioiodine treatment of Graves' disease and thyroid cancer in undiagnosed pregnancy. Can we rely on routine pregnancy testing?

INTRODUCTION: Radioiodine and most cytostatic treatments are contraindicated in pregnancy. Still, inadvertent therapy does occur. Radioiodine was given to two pregnant women with Graves' disease and thyroid cancer respectively, both in their 20th gestational week. Routine pregnancy tests based on urinary beta-hCG had failed to indicate pregnancy in both cases. METHODS: Estimation of doses to the foetuses and foetal thyroids. Scrutiny of pregnancy testing. RESULTS AND CONCLUSIONS: Doses to foetal thyroids were ablative (250-600 Gy). Total foetal dose in the Graves' patient was 100 mGy and compatible with survival, whereas a foetal dose of approximately 700 mGy together with induced hypothyroidism was fatal for the foetus of the cancer patient. Routine pregnancy tests may fail early and late in pregnancy. The possibility of pregnancy should be considered in all fertile women before therapy with radionuclides or cytostatic regimens, and a clinical investigation undertaken on wide indications with determination of serum beta-hCG, preferably together with an ultrasound examination.

The liquorice effect on the RAAS differs between the genders.

OBJECTIVE: Liquorice-induced increase in blood pressure (BP) is more profound in subjects with essential hypertension (HT) than in healthy individuals. Liquorice induces pseudohyperaldosteronism by inhibiting the 11beta-hydroxysteroid dehydrogenase type 2 and is also known to inhibit the renin-angiotensin-aldosterone system (RAAS). We explored the difference in response in BP, considering the RAAS and the genders. DESIGN: Patients with HT (eight men and three women, mean age 40.7 years) and healthy controls (13 men and 12 women, mean age 31.2 years) consumed 100 g of liquorice (150 mg glycyrrhetinic acid) daily for 4 weeks. METHODS: Blood, urine samples and BP were evaluated before and after 4 weeks of liquorice consumption and 4 weeks after cessation of liquorice consumption. RESULTS: The relative change in serum aldosterone levels differed between the genders (p < 0.02), men being more responsive than women, but not between patients with HT and healthy subjects. CONCLUSION: The liquorice-induced inhibition of aldosterone secretion differs between the genders and is not influenced by the BP levels. This difference between the genders has not been exposed before.

Liquorice in moderate doses does not affect sex steroid hormones of biological importance although the effect differs between the genders.

BACKGROUND/AIM: Liquorice is commonly consumed, at least in the western world, and we have earlier shown that even moderate doses of liquorice have significant effects on the cortisol metabolism by inhibiting 11beta-hydroxysteroid dehydrogenase type 2. The suggestion that liquorice decreases the testosterone levels in men makes it vital to study the effect of moderate doses of liquorice on sex steroid hormones. METHODS: Fifteen women and 21 men (healthy volunteers and subjects with essential hypertension) consumed 100 g of liquorice (150 mg glycyrrhetinic acid) daily in a 9-week, open-treatment trial. Blood and 24-hour urine samples were collected for hormone analysis before and after 4 weeks of liquorice consumption and 4 weeks after cessation of liquorice intake. RESULTS: The liquorice induced a moderate decrease in the serum concentrations of dehydroepiandrostenedione sulphate in men (p = 0.002). The relative change in serum levels of dehydroepiandrosterone sulphate differed between the genders (p = 0.03). No significant changes were observed in the serum testosterone levels after 4 weeks of liquorice consumption, and the urine excretion of androgens (etiocholanolone and androstenedione) did not change. CONCLUSIONS: Liquorice in moderate doses primarily affects the cortisol metabolism and only marginally the androgen hormones. Gender may influence the action of liquorice.

Ser49Gly of beta1-adrenergic receptor is associated with effective beta-blocker dose in dilated cardiomyopathy.

OBJECTIVE: Our objective was to evaluate the influence of polymorphisms at codons 49 and 389 of the beta1-adrenergic receptor (beta1-AR) on the response to beta-blockers and outcome in patients with dilated cardiomyopathy. METHODS: We genotyped both codons of the beta1-AR in 375 patients with dilated cardiomyopathy and 492 control subjects. RESULTS: Neither of the polymorphisms was associated with susceptibility for dilated cardiomyopathy. In a retrospective analysis of patients receiving beta-blockers, there was a significant association between long-term survival rate and codon 49 (P = .014) but not codon 389 (P = .08). Despite a similar mean heart rate (69 beats/min), patients with the Ser49 genotype tended to have higher doses of beta-blockade compared with Gly49 carriers (P = .065). In patients receiving a low dose of beta-blockade (< or = 50% of targeted full dose), the 5-year mortality rate was lower among Gly49 carriers than Ser49 patients (risk ratio [RR], 0.24; 95% confidence interval [CI], 0.07-0.80; P = .020). In patients receiving high doses of beta-blockers, there was no significant difference in outcome between genotypes (P = .20), which was attributable to a better outcome for Ser49 patients treated with a high dose of beta-blockade as compared with a low dose. Gly49 carriers had a similar survival rate with different doses of beta-blockers. With low-dose beta-blockers, both codon 49 (RR, 0.26; 95% CI, 0.08-0.89; P = .029) and codon 389 (RR, 2.42; 95% CI, 1.04-5.63, P = .039) were related to 5-year mortality rate. CONCLUSION: In patients with heart failure, the influence of codon 49 on the outcome and effect of beta-blockers appeared to be more pronounced than that of codon 389. The more common Ser49Ser genotype responded less beneficially to beta-blockade and would motivate genotyping to promote higher doses for the best outcome effect.

[New service for laboratory investigation of problematic cases. Four patients illustrate the value of EQUALIS]. / Ny möjlighet till laboratorieutredning av oklara fall. Fyra patientfall illustrerar värdet av EQUALIS.

In 1996, the Endocrinology Group in EQUALIS, in collaboration with The Thyroid Unit at The Section of Endocrinology at Sahlgrenska University Hospital, introduced a "patient-related" quality assurance program. Serum samples from patients with established or suspected thyroid disorder and/or results from thyroid-related biochemical measurements which were at variance with the clinical presentation, were analyzed by the participants of an external quality assurance program in endocrinology. The results from this program were informative as regards capacity, in the individual laboratories, for the evaluation of analytical and/or biological factors causing unexpected results from the measurement of thyroid-related serum components. We now present four clinical cases, which had offered diagnostic problems. EQUALIS, in collaboration with the participants of the external quality assurance program in endocrinology and on the basis of experiences from this program, now offers a diagnostic service for clinical chemistry laboratories and physicians when they are confronted with unexpected results from the immunochemical measurement of analytes included in the program.

Development of severe thyroid-associated ophthalmopathy in a patient with disseminated thyroid cancer treated with recombinant human thyrotropin/radioiodine and retinoic acid.

We present a case in which a patient with disseminated well-differentiated papillary thyroid cancer developed severe thyroid-associated ophthalmopathy. Eight years after initial surgery and ablative radioiodine therapy the patient was found to have multiple pulmonary metastases. The metastases showed poor uptake of radioiodine. An attempt was made to use 13-cis-retinoic acid in order to achieve a redifferentiation of the thyroid cancer cells before recombinant human thyrotropin (rhTSH) stimulated radioiodine therapy. The treatment did not improve the uptake of radioiodine. However, approximately 2 weeks after completion of the treatment the patient experienced discomfort in her eyes and then over the next months she developed a severe ophthalmopathy. The analyses of TSH receptor antibodies and S-thyroglobulin simultaneously showed a pronounced increase. An association between therapy given and severe ophthalmopathy cannot be excluded.

Epidemiology and primary prevention of thyroid cancer.

The purpose of this review is to provide an account of our present knowledge about the epidemiology of nonmedullary thyroid carcinoma, to discuss the effects of environment, lifestyle and radiation on the risk of developing thyroid cancer, and to discuss aspects on primary prevention of the disease. In areas not associated with nuclear fallout, the annual incidence of thyroid cancer ranges between 2.0-3.8 cases per 100,000 in women and 1.2-2.6 per 100,000 in men, women of childbearing age being at highest risk. Low figures are found in some European countries (Denmark, Holland, Slovakia) and high figures are found in Iceland and Hawaii. Differences in iodine intake may be one factor explaining the geographic variation, high iodine intake being associated with a slightly increased risk of developing thyroid cancer. In general, lifestyle factors have only a small effect on the risk of thyroid cancer, a possible protective effect of tobacco smoking has been recently reported. Because of the (small) increase in risk of thyroid cancer associated with iodination programs, these should be supervised, so that the population does not receive excess iodine. The thyroid gland is highly sensitive to radiation-induced oncogenesis. This is verified by numerous reports from survivors after Hiroshima and Nagasaki, the Nevada, Novaja Semlja and Marshal Island atmospheric tests, and the Chernobyl plant accident, as well as by investigations of earlier medical use of radiation for benign diseases in childhood. These reports are summarized in the review. There appears to be a dose-response relation for the risk of developing cancer after exposure to radioactive radioiodine. The thyroid gland of children is especially vulnerable to the carcinogenic action of ionizing radiation. Thus, the incidence of thyroid cancer in children in the Belarus area was less than 1 case per million per year before the Chernobyl accident, increasing to a peak exceeding 100 per million per year in certain areas after the accident. It is a social obligation of scientists to inform the public and politicians of these risks. All nuclear power plants should have a program in operation for stockpiling potassium iodide for distribution within 1-2 days after an accident.

[Increased risk of bone-fragility-related fractures in TSH--suppressive thyroxine treatment]. / Okad risk för benskörhetsfraktur vid TSH-suppressiv tyroxinbehandling.

Low concentration of serum thyrotropin (TSH) is a common finding in patients attending primary care as well as in apparently healthy elderly individuals. Low TSH concentration in apparently healthy elderly seems to be a significant risk factor for the development of dementia and for premature mortality. In thyroxine-treated women, TSH < 0.10 mlU/L appears to be a significant risk factor for fractures of the hip and vertebrae. Considering also the decrease in anti-thyroid immunoactivity observed in thyroxine treatment of autoimmune thyroiditis, as measured with antithyroperoxidase antibodies, we conclude that TSH concentrations during thyroxine substitution treatment should be held within the lower end of the health-associated reference interval.

Stunning of iodide transport by (131)I irradiation in cultured thyroid epithelial cells.

UNLABELLED: The existence of thyroid stunning (i.e., inhibited thyroidal iodide uptake after administration of diagnostic amounts of (131)I) is controversial and is currently a subject of debate. To our knowledge, the stunning phenomenon has not been investigated previously in vitro. METHODS: Growth-arrested porcine thyroid cells that formed a tight and polarized monolayer in a bicameral chamber were irradiated with 3-80 Gy (131)I present in the surrounding culture medium for 48 h. The iodide transport capacity after irradiation was evaluated 3 d later by measuring the transepithelial (basal to apical) flux of trace amounts of (125)I. RESULTS: The basal-to-apical (125)I transport decreased with increasing absorbed dose acquired from (131)I; a nearly 50% reduction was observed already at 3 Gy. Stable iodide at the same molarity as (131)I (10(-8) mol/L) had no effect on the (125)I transport. Cell number and epithelial integrity were not affected by irradiation. CONCLUSION: Stunning of iodide transport is detected after (131)I irradiation of cultured thyroid cells. The degree of inhibition of transport is dependent on the absorbed dose.