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PubMed2003

Percutaneous ultrasound-guided radiofrequency heat ablation for treatment of hyperthyroidism in cats.

OBJECTIVE: To determine efficacy and safety of percutaneous radiofrequency heat ablation for treatment of hyperthyroidism in cats. DESIGN: Prospective study. ANIMALS: 9 cats. PROCEDURE: Hyperthyroidism was diagnosed via clinical signs and high serum total (TT4) and free thyroxine (fT4) concentrations. One or 2 hyperfunctional cervical thyroid nodules were detected by use of scintigraphy and ultrasonography. If cats had 1 abnormal thyroid lobe, heat ablation was performed on that lobe; if cats had 2 abnormal lobes, heat ablation was applied to the larger lobe. Overall, heat ablation was performed 14 times in the 9 cats. Clinical signs and serum TT4, fT4, and calcium concentrations were monitored daily for 2 days after the procedure, weekly for the first month, and then monthly. Laryngeal function was evaluated and cervical ultrasonography and thyroid scintigraphy were also performed. Monitoring continued for as long as 9 months after heat ablation if a cat became euthyroid or until an owner chose an alternative treatment because of recurrence of hyperthyroidism. RESULTS: Serum TT4 and fT4 concentrations transiently decreased after all 14 heat ablation procedures (< or = reference range after 10 of 14 treatments) within 2 days after the procedure. Cats were euthyroid for 0 to 18 months (mean, 4 months). Hyperthyroidism recurred in all cats. Adverse effects included transient Horner's syndrome (2 cats) and laryngeal paralysis without clinical signs (1 cat). CONCLUSIONS AND CLINICAL RELEVANCE: Percutaneous heat ablation as a treatment for hyperthyroidism in cats is effective transiently but not permanently.

Administration, Cutaneous↗
PubMedDate not supplied

Status asthmaticus associated with hyperthyroidism.

The syndrome of asthma and hyperthyroidism is uncommon and has been reported to occur approximately once every three hundred admissions for asthma. The frequency may be higher with an increased awareness; however, when this syndrome is present, it is usually associated with a very severe form of asthma necessitating frequent emergency treatment and hospitalization. Although severe asthma alone or together with side effects of drugs used in its treatment may mimic many symptoms associated with hyperthyroidism, an awareness of this syndrome will enable one to easily establish the diagnosis. In these cases, the hyperthyroidism may be iodide induced especially in those patients with diffuse or nodule thyroid goiter. Since this form of hyperthyroidism may be self-limiting, initial treatment should include a trial of propylthiouracil or methimazole up to six months. Medical therapy of the hyperthyroid results in dramatic improvement of the asthma.

Asthma↗
PubMed1988

Comparison of covalent binding from halothane metabolism in hepatic microsomes from phenobarbital-induced and hyperthyroid rats.

1. Hepatic microsomal suspensions from rats pretreated with saline, phenobarbital or triiodothyronine were incubated with 14C-halothane under aerobic and anerobic conditions. 2. Metabolism of halothane by microsomes from phenobarbital-induced rats under anaerobic conditions resulted in covalent binding of 14C to microsomal lipids, and to a lesser extent, microsomal proteins, as seen in previous studies. Covalent binding was decreased with incubation under aerobic conditions. 3. Metabolism of halothane by microsomal suspensions from hyperthyroid rats produced much less covalent binding to microsomal lipids and proteins, with binding similar to, or less than, that observed with microsomes from saline-treated rats. The covalent binding of halothane to protein of microsomes from hyperthyroid rats was dependent upon metabolism, and was inhibited by SKF 525A, reduced glutathione, or cytosol. 4. The in vitro observations with respect to covalent binding are inconsistent with previous reports on halothane hepatotoxicity in hyperthyroid rats in vivo. This inconsistency and the relatively small extent of covalent binding with microsomes from hyperthyroid rats observed, suggests that covalent binding is not an important mechanism of halothane hepatotoxicity in the hyperthyroid rat model.

Animals↗
PubMed1989

Pathogenetic role of thyrotropin receptor antibody in the development of hyperthyroidism following primary hypothyroidism.

The authors measured thyrotropin binding inhibitory immunoglobulin (TBII), thyroid stimulating antibody (TSAb), and thyroid stimulation blocking antibody (TSBAb) sequentially in patients who developed hyperthyroidism following primary hypothyroidism, and compared changes in these various functional parameters of thyrotropin receptor antibody (TRAb) with clinical manifestations, in order to investigate the role of TRAb in the development of hyperthyroidism following primary hypothyroidism. In a patient with goitrous chronic thyroiditis, TBII, TSAb and TSBAb were not detected at the initial hypothyroid phase. But with appearance of TBII and TSAb, the patient developed hyperthyroidism. In a patient with primary nongoitrous myxedema, initially high TBII and TSBAb were detected without TSAb activity. His TSBAb disappeared and TSAb appeared with development of goiter growth and hyperthyroidism. These two mechanisms, that is, appearance of previously absent TSAb and conversion of TSBAb to TSAb, might play a causative role in the development of hyperthyroidism following primary hypothyroidism. These phenomena might be evidence that Graves' disease, chronic thyroiditis, and primary nongoitrous myxedema are on a continuing spectrum of a common syndrome sharing similar pathophysiology, at least with respect to TRAb.

Adult↗
PubMedDate not supplied

Duration of the P wave and P wave dispersion in subclinical hyperthyroidism.

OBJECTIVE: To determine whether the values for P wave dispersion (Pdis) and adjusted Pdis, which are simple noninvasive electrocardiographic markers to detect paroxysmal atrial fibrillation, differ in patients with endogenous subclinical hyperthyroidism in comparison with those in healthy control subjects. METHODS: We measured the maximal P wave duration and the difference between the maximal and the minimal P wave duration (Pdis) from the 12-lead surface electrocardiogram of 36 patients with endogenous subclinical hyperthyroidism and of 22 age- and sex-matched healthy control subjects. Adjusted Pdis (Pdis/square root of the number of measured electrocardiographic leads) was also calculated from each electrocardiogram. RESULTS: The minimal P wave duration was significantly shorter in patients with subclinical hyperthyroidism than in healthy control subjects (P<0.001). Pdis and adjusted Pdis were also significantly higher in the patient group than in the control subjects (P<0.05). By univariate analysis, only thyrotropin levels were found to be associated with adjusted Pdis (r = -0.28; P = 0.03). CONCLUSION: Pdis and adjusted Pdis differed in patients with endogenous subclinical hyperthyroidism in comparison with those values in healthy control subjects. Thus, these simple electrocardiographic markers may be useful for identifying patients with endogenous subclinical hyperthyroidism who are at risk for paroxysmal atrial fibrillation.

Adult↗
PubMed2000

Thyroid status and the levels of thyroid auto-antibodies in the sera of hyperthyroid and goitrous subjects.

OBJECTIVES: To determine the prevalence of thyroid auto-antibodies in specimens sent to Parirenyatwa hospital laboratory for thyroid function testing and to compare the thyroid status of these patients with that of apparently healthy subjects. DESIGN: Cross sectional study. SETTING: Immunology and radio-immunoassay laboratories, Parirenyatwa hospital, Department of Chemical Pathology, and Blood Transfusion Services, Harare. SUBJECTS: 212 blood samples submitted for thyroid function testing and 230 blood samples from apparently healthy blood donors. MAIN OUTCOME MEASURES: Serum concentrations of free triiodothyronine (FT3), thyroxine (FT4), thyrotropin (TSH), and thyroid auto-antibodies; anti microsomal (M Ab) and antithyroglobulin (Ag Ab) antibodies. RESULTS: The hyperthyroid subjects had median serum TSH level of 0.027 mIU/L (Q1 = 0.006, Q3 = 0.052), median serum FT3 level of 15.895 pmol/L (Q1 = 10.563; Q3 = 30.111), and a median serum FT4 level of 45.513 pmol/L (Q1 = 30.256; Q3 = 63.910). The goitrous subjects had median serum TSH level of 0.390 mIU/L (Q1 = 0.157; Q3 = 0.745). The blood donor group had median TSH value of 0.724 mIU/L (Q1 = 0.471; Q3 = 1.170). (Normal ranges: TSH = 0.167 to 2.80) Amerlite TSH-30 diagnostic kit; FT3 = 3.4 to 7.2 pmol/L; FT4 = 11 to 24 pmol/L) Amelex-MAB diagnostic kits) Thirty nine percent of the hyperthyroid subjects had either positive M Ab or Tg Ab or both. None of the goitrous subjects and the blood donors tested positive for neither M Ab, nor Tg Ab. No significant difference was found between the blood donors and the goitrous subjects for serum FT4 (P = 0.51). However, significant differences were found between the goitrous, the blood donor and the hyperthyroid groups with regards to serum TSH, serum FT4, and serum FT3 levels (p = 0.001). CONCLUSION: Our findings indicate that the occurrence of thyroid auto-antibodies among the blood donors and the goitrous population was uncommon, but high in the hyperthyroid subjects. The increase of iodine intake through iodine prophylaxis could have had the side effects of iodine induced hyperthyroidism.

Adolescent↗
PubMed1978

[Erythrocyte carbonic anhydrases in patients with hyperthyroidism (author's transl)].

Human erythrocyte carbonic anhydrase B (CA-B) and C (CA-C) were measured by a specific and immunological method and erythrocyte 2,3-diphosphoglycerate (2,3-DPG) concentrations were measured using a kinetical method. The levels of CA-B and CA-C were determined in normal subjects, patients with hyperthyroidism and patients with hypothyroidism, using the method of single radial immunodiffusion. A decrease of CA-B levels and an elevation of 2,3-DPG concentrations were noted in hyperthyroidism. The CA-C levels appeared to be essentially unchanged. Closely negative correlations were observed between CA-B levels and T3 resin sponge uptake T4, protein bound iodine levels, or 2,3-DPG concentrations. Simultaneously, the specific activity of CA-B and CA-C was determined using the immunoadsorbent method. The specific activity of CA-B elevated in hyperthyroidism two times higher than that of normal subjects. The levels of rabbit erythrocyte CA-B, CA-C and 2,3-DPG were measured in experimental hyperthyroidism by the methods employed for human erythrocytes. Thyroxin and 3,5,3'-triiodothyronine were administered orally for 30 days. A significant decrease in CA-B levels was observed after 30 days, although CA-C levels did not change significantly. These findings suggest that the steady state levels of CA-B is affected more readily than that of CA-C by thyroid hormone. An elevation of the specific activity of CA-B or the concentrations of 2,3-DPG was noted as seen in human hyperthyroidism. The effect of thyroid hormone on the biosynthesis of CA-B and CA-C was studied in vitro using rabbit reticulocyte lysates. The biosynthesis of CA-B was inhibited by the addition of thyroxin in this system, although no such an inhibitory effect was observed in the biosynthesis of CA-C. Th e clinical or pathological significances were discussed in relation to the changes in these isozymes and 2,3-DPG in red cells.

Adult↗
PubMed1999

[Hyperthyroidism in a premature infant due to transplacental passage of maternal thyrotropin receptor antibodies].

The duration of the stimulating effect of transplacental transferred thyrotropin-receptor-antibodies (TRAb) is discussed by the example of a 23 years old woman suffering from Graves' disease with a severe hyperthyroidism. She became pregnant six weeks after the diagnosis was obtained and then discontinued her antithyroid medication on her own responsibility. On a check-up in the 20th week of pregnancy, a hyperthyroidism was once more found, leading to a therapy with propylthiouracil, which however, was again interrupted by the patient a few weeks later. In the 32nd week, she gave birth to a male child that already presented with distinct signs of thyrotoxicosis and developed a continuous deterioration of the condition, including a tachycardia with up to 190 beats per minute, fever, tremor and a respiratory disorder. Assay of the newborn serum revealed a severe hyperthyroidism. The TRAb level was 180 U/l (normal range < 15). A therapy with propranolol and prednisolone was initiated, leading to a significant improvement of the general condition. Nevertheless, after 12 days, there was still no notable decrease of the hormone levels. Therefore an antithyroid medication was started, which caused normal thyroid hormone levels within 9 days. However, after the therapy was stopped, a hyperthyroidism was again observed within one week, requiring another, low-dose antithyroid medication, which was administered for 26 days. After this period, the TRAb level was down to 25 U/l and no more hyperthyroidism was found. The biological half-life of the TRAb was 20 days in our case.

Adult↗
PubMed1999

Increased glucose synthesis in renal tubule fragments from hyperthyroid rats.

Rates of glucose synthesis from several substrates were examined in renal tubule fragments from hyperthyroid rats. A hyperthyroid state was induced by daily intraperitoneal injections of thyroxine (T4) (100 microg/100 g body weight) for 14 days. At the end of the experimental period, plasma triiodothyronine and T4 levels were six and eight times higher, respectively, than initial values. Hyperthyroid rats gained less weight and had lower blood glucose despite an increased food intake. In both control and hyperthyroid rats, rates of glucose production by renal tubule fragments were higher with glutamine and glycerol than with lactate, alanine, or glutamate. T4 treatment induced a significant increase in the de novo glucose synthesis from all substrates, except glutamine. The highest percent increase was obtained with alanine (64%), compared with 31-40% for glutamate, lactate, and glycerol. The T4 treatment induced increase in glucose synthesis by renal tubule fragments suggests that renal gluconeogenesis contributes to enhance glucose production in hyperthyroidism.

Animals↗
PubMed2000

[Seasonal variations in the diagnosis of hyperthyroidism].

Seasonal variations in the frequency of thyrotoxicosis are known for a long time. Both, variations in the temperature and in the iodine supplementation are believed to affect the incidence of the diagnosis of hyperthyroidism. Seasonal variation of the incidence of hyperthyroidism was investigated before and after increase of salt iodination in 1990/1991. In the period from January 1987 to December 1995 hyperthyroidism was diagnosed for the first time on 4711 patients in our department. This population was subdivided according to etiology (Graves' disease, autonomous nodular goiter) and grade of hyperthyroidism (preclinical or clinical form). The so formed groups were divided according to the month of diagnosis into further 12 subgroups. Significant differences in month to month variation were found in the patients suffering from Graves' disease and autonomous nodular goiter with preclinical hyperthyroidism after increased iodine supplementation. The peak incidence of the diagnosis occurred in June, July, and August. Our results indicate that improved iodine supplementation may be the main cause of seasonal variations in the incidence of thyrotoxicosis.

Austria↗
PubMed2000

[Treatment of hyperthyroidism with radioiodine: effects of administered dose on complications and thyroid function].

BACKGROUND: Radio-iodine is a definite therapy for Graves disease hyperthyroidism. However, the optimal dosage is still debatable. AIM: To assess the effects of different radioiodine doses on thyroid function and complications in patients with hyperthyroidism. MATERIAL AND METHODS: A retrospective analysis of 139 patients with hyperthyroidism, treated with ratio-iodine between 1988 and 1998. Radio iodine dose used was classified as low (< 10 mCi), intermediate (10-14.9 mCi) or high (> or = 15 mCi). RESULTS: Thirty-five patients were treated with low doses, 33 with intermediate doses and 71 with high doses. There were no differences between these patients in age, disease severity, frequency of post treatment euthyroidism or complications. Patients treated with low doses had a higher frequency of persistent hyperthyroidism than patients treated with high doses (25.7 and 4.2% respectively, p < 0.001). Likewise, the frequency of subsequent hypothyroidism was 60% in patients treated with low doses and 84.5% of those with high doses, in whom it also appeared earlier. Associated complications were clinically irrelevant. In seven patients, Graves ophthalmopathy progressed after treatment, but this progression was not associated with the dose used. CONCLUSIONS: Radio iodine in high doses is useful, safe and effective for the treatment of Graves hyperthyroidism.

Adolescent↗
PubMed2000

[Amiodarone-induced hyperthyroidism].

Amiodarone is extensively used in cardiology practice because of its excellent antiarrhythmic properties. It produces alterations in thyroid functional because it contains 37% iodine and it is structurally similar to the thyroid hormones. Amiodarone inhibits 5'-deiodinase in the liver. The incidence of amiodarone-induced hyperthyroidism is between 6% and 12% of treated patients. The figures for pediatric patients are similar. Determination of tri-iodothyronine (T3), thyroxine (T4) and thyroid-stimulating hormone (TSH) plays an important role in the diagnosis and follow-up of thyroid alterations. Treatment options in amiodarone-induced hyperthyroidism in children include thionamide, potassium perchlorate, and prednisone. We present the case of hyperthyroidism secondary to amiodarone in a 10-year-old boy with Marfan's syndrome who was admitted several times for crises of paroxysmal supraventricular tachycardia and atrial fibrillation. After amiodarone treatment he presented a clinical and analytical picture of hyperthyroidism with very low TSH levels and increased free-T4 levels. Thyroid echography and scintigraphy were normal. Treatment with thiamazole did not alter the clinical picture, which returned to normal after prednisone administration. Currently, prednisone is being slowly withdrawn.Amiodarone. Hyperthyroidism. Antiarrhythmics.

Amiodarone↗
PubMed2000

[Thyroid cancer in patients with hyperthyroidism].

OBJECTIVE: The prevalence of thyroid carcinoma in hyperthyroidism remains controversial. The aim of this retrospective study was to evaluate prevalence. PATIENTS AND METHODS: The prevalence of thyroid carcinoma was studied in 861 patients operated for clinical or infraclinical hyperthyroidism between 1992 and 1999. One hundred and fifty patients had a hot nodule, 13 of them with an associated goiter. Four hundred five patients had Graves' disease and 306 had a multinodular goiter. Multiple sections were made in all surgical specimens for pathology study. RESULTS: Prevalence in solitary nodules was 1.45%. For Graves' disease patients, it was 4.1%. Prevalence among patients with multinodular goiter was 4.9%. Among the cancers, 83% were microcarcinoma. Parathyroid morbidity after subtotal and total thyroidectomy was 0.56% and recurrent hyperthyroidism occurred in 1.6%. CONCLUSIONS: These findings are grossly identical to those observed in simple, nontoxic diffuse multinodular goiter. It would therefore be difficult to incriminate hyperthyroidism as playing a causal role in the development of thyroid cancer. These results do however provide an argument favoring total or near total thyroidectomy when surgery is performed in patients with hyperthyroidism.

Adult↗
PubMed1998

Prognostic significance of thyroid antibodies in hyperthyroid patients treated with antithyroid drugs.

Lymphocytic infiltration of the thyroid gland in patients with hyperthyroidism is associated with the presence of serum antithyroidal microsomal antibodies (TMA) and serum antithyroglobulin antibodies (TGA). The aim of this study was to evaluate the clinical significance of TMA and TGA during and after treatment of hyperthyroidism with antithyroidal drugs. One hundred and fifty-four hyperthyroid patients were treated for 18 months with methimazole and then followed up for 18 months or more (mean, 24.8 +/- 12.6 months). Patients were classified into three group. group I, patients negative for TGA and TMA before and during 18 months of treatment, group II patients positive for TMA but negative for TGA before and during 18 months treatment and group III patients who were positive for both TGA and TMA before and during treatment. The relapse rates after discontinuation of treatment in these group were 44.7% (17 of 38), 29% (18 of 62) and 11.1% (6 of 54), respectively. The value in group I was significantly higher than that in group III (P < 0.01). These results show that presence of TMA and TGA influence the prognosis of patients with hyperthyroidism treated with methimazole with regard to relapse. Those patients who had both antibodies were least likely to have a relapse and those who had neither antibody before and during treatment were most likely to have a relapse of hyperthyroidism.

Adolescent↗
PubMedDate not supplied

Hyperthyroidism with concurrent thyroid cancer.

The occurrence of thyroid malignancy is considered a rare event in hyperthyroid patients. With the aim of assessing the clinical relevance of this association, we have analyzed the incidence of thyroid cancer in hyperthyroid patients treated by surgery. The incidence of thyroid cancer was retrospectively evaluated in 202 hyperthyroid patients who underwent thyroidectomy during a twenty-year period. A thyroid cancer was diagnosed in 12 cases (5.9 per cent). Histologic examination revealed the presence of papillary carcinoma in 9 cases, follicular carcinoma in 1 case and Hürthle cell carcinoma in 2 cases. The association between thyroid cancer and hyperthyroidism was more frequent in toxic adenomas (17.8 per cent) than in toxic diffuse (5.3 per cent) or multinodular goiters (1.7 per cent). In 8 patients they presented as an occult carcinoma (maximum diameter below 1 cm), but unfavourable histologic features, such as local invasiveness and multifocality, were found in 5 of them. Follow-up data indicate that all 12 patients are currently alive and apparently free of disease. Hyperthyroid patients, particularly those affected by toxic adenomas, should be carefully evaluated to exclude the presence of concurrent malignancy. A special attention should be made moreover to the presence of "occult" lesions that, in our study was characterized in a higher proportion (62.5 per cent) of cases, by unfavourable histologic features.

Adult↗
PubMedDate not supplied

[Proceeding: Production rate, metabolic clearance rate and mean plasma concentration of cortisol in hyperthyroidism (author's transl)].

The adrenocortical function was studied in 23 patients with hyperthyroidism and compared with a group of 15 normal subjects. Parameters of adrenal function were determined with 1,2(3)H-cortisol. The half-life of cortisol is significantly shortened in hyperthyroidism, as compared to normal subjects (49,5 +/- 6,6 min vs 68,3 +/- 10,5 min) and metabolic clearance rate is increased (418,5 +/- 89,5 L/24 h vs 237,5 +/- 48,5 L/24 h, for normal subjects). The production rate of cortisol, calculated from specific and cumulate activities of THE and THF is increased in hyperthyroidism expressed as mg/24 h or mg/m2/24 h (respectively : 26,7 +/- 7,8 mg/24 h vs 15,7 +/- 3 mg/24 h and 16,9 +/- 4,6 mg/m2/24 h vs 9,5 +/- 1,8 mg/m2/24 h). The mean plasma concentration, calculated as the radio (see article) is not statiscally different in hyperthyroid and normal subjects (6,8 +/- 2,1 microg/100 ml vs 7,3 +/- 1,9 microg/100 ml). 7 patients were reinvestigated after treatment of thyrotoxicosis when they were clinically and biologically in euthyroid state. All the values were normalized, without statistically significant difference from control (T 1/2 = 65,4 +/- 18 min, Metb Cl. Rate : 255 +/- 64,5 L/24 h, production rate : 15,6 +/- 1,8 mg/24 h and 9 +/- 1,4 mg/m2/24 h. mean plasma concentration : 6,8 +/- 2,8 microg/100 ml). Shortened cortisol half life, increased metabolic clearance rate and production rate, and normal mean plasma concentration have been reported in hyperthyroidism (Peterson, Copinschi, Gallagher). These changes, secondary to thyroid hormone excess, are the consequences of increased hepatic catabolism of cortisol. The activity of 11 OH steroid deshydrogenase is increased, as demonstrated by increased ratio (see article) in normal subjects (0,001 less than p less than 0,005). There is a high proportion of 17 kéto metabolites (E, DHE, THE) whose feed-back effect is weak as compared to 17 OH metabolites (F, DHF, THF). The hypothalamo-hypophyso-adrenal system is stimulated to maintain a normal plasma concentration. The fact that the mean plasma concentration is normal despite the increased production rate suggest that changes are rather due to increased catabolism than to central effect of thyroid hormones.

Hydrocortisone↗
PubMed2002

[Cardiovascular effects of hyperthyroidism and their treatment].

The most striking clinical effects of hyperthyroidism are on the heart. These effects concern both heart rate and function. The increased contractility is mainly based on the indirect inotropic effect of peripheral vasodilation as a consequence of hyperthyroidism. Although contractility at rest is enhanced in hyperthyroidism, cardiac reserve is decreased due to diminished chronotropic, inotropic and vasodilatory reserve. In hyperthyroid patients, the clinical impression is often that of a hyperadrenergic circulation. However, the sensitivity of the heart for catecholamines is not increased. The diminution of palpitations by beta-adrenergic blockers in hyperthyroid patients is due to both a decrease in heart rate and atrial extrasystoles, and is not the consequence of a normalisation of cardiac contractility. Heart failure is almost exclusively found in patients with pre-existing cardiac disease. In the case of serious heart failure a rapid reduction of circulating thyroid hormone by means of thyreostatics is important as well. There is no consensus as to whether patients with thyrotoxic atrial fibrillation should be treated with oral anticoagulants. However, most experts recommend oral anticoagulants for elderly patients (> 60 years) or patients with additional risk factors for embolism.

Adrenergic beta-Antagonists↗
PubMed2002

Changes of arterial pressure in patients with hyperthyroidism during therapy.

BACKGROUND: Hyperthyroidism affects the circulatory system, producing an increase in cardiac output and an enhanced vascular bed volume. These phenomena are important in the regulation of blood pressure. The present study was designed to evaluate the effects of short- and long-term treatment of hyperthyroidism on arterial pressure, taking into account the indices of cardiac function and peripheral vessel resistance. MATERIAL/METHODS: Fifty-one patients with hyperthyroidism and 30 healthy controls were investigated. The patients were examined before treatment, two weeks after initiation of therapy, and after attainment of a euthyroid state. Thiamazole was used as the antithyroid agent. Blood pressure and serum thyroid hormones were determined and ultrasonographic examination was performed on all the subjects, after the application of a diet containing 120 mmol of sodium and 70 mmol of potassium for three days. RESULTS: Patients with hyperthyroidism had higher systolic blood pressure and lower diastolic blood pressure than the healthy controls. After short-term treatment, systolic blood pressure returned to normal, while diastolic blood pressure was normalized only after long-term treatment. CONCLUSIONS: Regulation of blood pressure in patients with hyperthyroidism is a complex process. Systolic blood pressure is mainly related to cardiac output and returns to normal range shortly after the initiation of therapy, while diastolic blood pressure is related to peripheral vascular resistance and is normalized after long-term treatment.

Adolescent↗