Search PubMed⌕ Search

Biomedical subjects

B Nygaard

Publications and source records attributed to B Nygaard.

At least 37 records · Page 2Linked to original sources
PubMed1998

Normalization of serum thyrotrophin by means of radioiodine treatment in subclinical hyperthyroidism: effect on bone loss in postmenopausal women.

BACKGROUND: Patients with subclinical hyperthyroidism (reduced serum TSH and normal free T4 and T3 concentrations) have slightly increased bone turnover and might have reduced bone mass, especially among postmenopausal women (due to concomitantly reduced oestrogen production), as also seen during suppressive L-T4 treatment. OBJECTIVE: We have evaluated whether normalization of serum TSH using radioiodine treatment (RAI) in postmenopausal women with a nodular goitre and subclinical hyperthyroidism, protects against bone loss? DESIGN: Prospective, non-randomized study, outpatients 2 years follow-up. PATIENTS: Postmenopausal women with a nodular goitre, biochemically subclinical hyperthyroidism (TSH < 0.2 mU/I, and signs of a growing goitre or compression symptoms. Sixteen were treated with RAI (median dose 555 MBq) (+RAI), whereas 12 were followed without treatment (-RAI). MEASUREMENTS: Serum TSH (third generation technology), free T4 and T3 indices, and bone mass (BMD) as measured by Dual Photon Absorptiometry (4 in each group) (only spine) or Dual X-ray Absorptiometry (DEXA) (both spine and hip), were measured yearly for up to 2 years. RESULTS: The two groups did not differ regarding age, thyroid hormone parameters, and absolute levels of BMD at spine and hip. RAI resulted in normalization of TSH in all 16 women, and FT4I as well as FT3I decreased to 78% after one year (P < 0.01). These parameters did not change in the untreated group, thus serum TSH remained reduced. BMD at the spine tended to increase (n.s.) after RAI to (median) 101.9% after one year, and 101.5% after 2 years. In contrast the -RAI group experienced a continued fall in BMD to 97.3% after one year, and 95.5% after 2 years, both reduced as compared to the +RAI group (P < 0.02). BMD of the hip also increased after RAI, to 102.3% after one year, and 101.7% after 2 years. In contrast BMD in the -RAI group decreased to 94.8% after one year, and 98.0% after 2 years, both lower than in the +RAI group (P < 0.01). CONCLUSIONS: Subclinical hyperthyroidism due to a nodular goitre in postmenopausal women resulted in a continued loss of bone mass of about 2% per year. Radioiodine treatment resulting in normalization of serum TSH prevented this continued bone loss for at least 2 years. Our study supports earlier intervention in such patients.

Aged↗
PubMed1998

Changes in the thyroid technetium-99m scintigram after antithyroid and subsequent radioiodine treatment for solitary autonomous nodules.

In patients with solitary autonomous thyroid nodules, the treatment of choice is radioiodine (131I) therapy, eventually preceded by antithyroid drugs to avoid aggravation of hyperthyroidism. The aim of this study was to evaluate the scintigraphical results of 131I treatment when using antithyroid pretreatment. Twenty-four patients having a solitary autonomous thyroid nodule were studied. A technetium-99m (99mTc) pertechnetate scintigraphy was performed at the time of diagnosis, when serum thyrotropin (TSH) had been normal for about 3 months on antithyroid drug treatment, and finally when serum TSH was normalized after 131I treatment. The primary scintigram showed suppression of 99mTc pertechnetate in the paranodular thyroid tissue in all patients. The second scintigram showed normal uptake in the paranodular tissue in 22 patients and a continuing suppression of the paranodular tissue in 2 patients. The third scintigram showed a solitary adenoma in 14 patients with none or almost no uptake in the paranodular tissue, resembling the first scintigram. In 6 patients an adenoma was still present, but uptake was seen in the paranodular tissue; in 3 patients a homogenous uptake without any sign of the previous nodule, and in 1 patient very low uptake in the gland was seen. Four patients developed hypothyroidism in the follow-up period of approximately 1 year. Pretreatment with antithyroid drugs induced an increase in serum TSH, stimulating the paranodular tissue. 131I will therefore be distributed in the whole thyroid gland, and not only in the autonomous solitary nodule. After 131I treatment, we continuously found a solitary nodule with low uptake in the paranodular tissue in 20 of 24 patients.

Adenoma↗
PubMed1998

Observer variation in the clinical and laboratory evaluation of patients with thyroid dysfunction and goiter.

Three endocrinologists assessed thyroid function (hypothyroid, possibly hypothyroid, euthyroid, possibly hyperthyroid, or hyperthyroid), thyroid size (small, medium, or large), thyroid type (diffuse, nodular, or solitary nodule), and diagnosis and treatment options in 55 patients (47 women and 8 men) with a median age of 43 years (range 19 to 74) suspected of thyroid disease. The observers were presented stepwise for the (1) patient, clinical examination, and patient history; (2) blood tests; (3) 99mTc-pertechnetate scintigraphy; and (4) ultrasonography. The reproducibility was assessed by means of the K coefficient. Compared with evaluation of the patient alone, agreement on thyroid dysfunction was almost perfect when the results of the blood tests were known. The K values for pairs of observers rose significantly from 0.55 to 0.65 to 0.88 to 0.93. All three observers altered their opinion as to thyroid dysfunction in one third of the patients when the blood tests were known. Compared with evaluation of the patient alone, agreement on the morphology of the thyroid gland did not improve significantly in spite of access to thyroid scintigraphy; with the addition of thyroid ultrasound, agreement improved significantly for some pairs of observers. The three observers agreed on the rough estimate of thyroid size in only 36% of the patients. When all information was available, the three observers agreed on diagnosis and treatment category in 60% of the patients. Doctors should bear in mind the considerable observer variation when they evaluate patients with suspected thyroid disease.

Adult↗
PubMed1997

[Thyroid stimulating antibodies in pregnant women with Graves' disease and neonatal thyrotoxicosis].

Thyroid stimulating antibodies (TSAb) are thought to be involved in the initiation of Graves' disease, and thyrotoxicosis in the neonatal period is often caused by TSAb passing the placental barrier. We wanted to evaluate measurement of TSAb levels as a possible predictor of neonatal thyrotoxicosis in pregnant patients with Graves' disease. We retrospectively evaluated 18 consecutive pregnant patients with Graves' disease. In 16 patients TSAb were measured in early pregnancy, six had increased values. In 14 of 18 patients normal values were found in late pregnancy and none of the children developed neonatal thyrotoxicosis. Two patients had greatly elevated TSAb values, and their children had neonatal thyrotoxicosis. Two patients had slightly elevated TSAb levels and delivered normal children. We conclude that all pregnant patients with an actual or a history of Graves' disease, should have measured TSAb. High TSAb values in late pregnancy indicate a considerable risk of neonatal thyrotoxicosis.

Adult↗
PubMed1997

Thyroid volume and function after 131I treatment of diffuse non-toxic goitre.

OBJECTIVE: Traditional treatment of diffuse non-toxic goitre are thyroid hormone suppression or surgery. When treating nodular non-toxic goitre with 131I treatment a reduction in thyroid volume to about 50% has been observed. In the present study we evaluated the effect of 131I treatment of diffuse non-toxic goitre. DESIGN: Retrospective study of patients treated for a diffuse non-toxic goitre and followed by evaluation of thyroid volume measured by ultrasound. PATIENTS: Ten selected patients from our out-patient clinic with diffuse non-toxic goitre. MEASUREMENTS: Thyroid volume was measured by ultrasound and thyroid function by serum values of T4, T3, T3 uptake ratio, TSH, TSH receptor antibodies and thyroid peroxidase antibodies (anti-TPO). Measurements were performed before and 1, 3, 6 and 12 months (and 18 months (n = 7), thyroid volume measured in six patients)) after 131I treatment. RESULTS: Thyroid volume declined in all patients from median 41 (range 27-160) ml to 20 (range 9-108) ml over 1 year, a reduction of 47%. One patient developed transient and one persistent hypothyroidism in the follow-up period. Both had elevated anti-TPO levels before treatment (331 and 9185 U/ml) and demonstrated titre increases of 2.5 and 30 times after 3 and 6 months, respectively. Pretreatment values were reached after 1 year. The other eight patients had normal anti-TPO levels and free T4 and T3 indices did not change during follow-up, whereas serum TSH levels demonstrated upward trends within the normal range (P < 0.05). TSH receptor antibodies were normal and remained so in all patients. CONCLUSIONS: 131I treatment of diffuse non-toxic goitre reduces thyroid volume by approximately 50% within 12-18 months. Hypothyroidism, during a limited follow-up period, developed only in patients with positive anti-TPO levels before treatment.

Adult↗
PubMed1997

Thyrotropin receptor antibodies and Graves' disease, a side-effect of 131I treatment in patients with nontoxic goiter.

The use of 131I treatment in patients with benign nontoxic goiter is increasing, and the described side-effects are few. In this paper we describe appearance of TSH receptor antibodies (TRAb) and concomitant development of hyperthyroidism as a side-effect of 131I treatment in patients with nontoxic goiter. In this retrospective study, 191 consecutive patients with 131I-treated nontoxic goiter are described. Nine patients (5%) developed hyperthyroidism 3 months after 131I treatment, and 5 patients (3%) developed radiation thyroiditis within the first month. Frozen sera were analyzed for thyroid peroxidase antibodies (anti-TPO) in 130 patients before 131I treatment. In 21% of these, serum levels of anti-TPO were over 200 U/mL. The complication frequency of Graves'-like hyperthyroidism and hypothyroidism was 51% in patients with elevated anti-TPO (n = 27) and 15% in patients with normal serum anti-TPO levels (P < 0.00005). TRAb, anti-TPO, and thyroglobulin were followed in patients developing hyperthyroidism or radiation thyroiditis and in 10 control patients remaining euthyroid. At the time of 131I treatment, all patients had serum TRAb values within the normal range. Three months after administration of 131I, the patients developing hyperthyroidism had a transient extensive rise in serum TRAb and anti-TPO levels parallel to a rise in the serum free T4 index. In patients developing radiation thyroiditis, serum TRAb values were normal. In control patients, serum TRAb and anti-TPO values were both within the normal range throughout the observation period. In conclusion, hyperthyroidism can be triggered by 131I in patients with nontoxic goiter, not only related to radiation thyroiditis but also as a Graves'-like hyperthyroidism induced by TRAb. Elevated anti-TPO pretreatment is a marker of an increased risk of side-effects to 131I treatment in nontoxic goiter.

Adult↗
PubMed1996

Interaction between microwave-induced brain hyperthermia and high dose rate radiation in the BT4 An brain glioma in rats.

The cerebral BT4An glioma model in BD IX rats was used to study the effect of hyperthermia given in combination with radiotherapy (thermoradiotherapy) in the treatment of brain tumours. A single treatment with high dose rate radiation was given to a local brain field. Local brain hyperthermia was given at 42.4 degrees C for 45 min by externally applied microwaves (700 MHz), immediately before radiotherapy (10 Gy). In a pilot study, thermoradiotherapy increased the median life span with 20 days compared to controls, which was significantly better than that observed after radiotherapy alone (7 days). In an extended experiment the corresponding figures for thermoradiotherapy, hyperthermia alone and radiotherapy alone were 12.5, 3.5, and 3.5 days, respectively. Thermoradiotherapy was significantly better than radiotherapy and hyperthermia alone. There was no acute mortality in these experiments. Neurological side-effects were infrequent, of slight degree and reversible. The present study shows that a survival benefit of adding hyperthermia to radiotherapy can be achieved without unacceptable neurological side-effects in an animal glioma model.

Animals↗
PubMed1996

Improvement of upper airway obstruction after 131I-treatment of multinodular nontoxic goiter evaluated by flow volume loop curves.

Symptoms of tracheal-esophageal compression are often related to a large nontoxic goiter. The aim of the present study was to evaluate to what degree upper airway obstruction, as measured by flow volume loops, FIF50% and FEF50%/FIF50% (Forced Expiratory Flow at 50% of the vital capacity/ Forced Inspiratory Flow at 50% of the vital capacity) exists in nontoxic multinodular goiter, and whether changes occur after 131I-treatment. Thirteen patients with large multinodular nontoxic goiters were evaluated by estimation of FIF50%, FEF50%/FIF50% ratio and a graphic plot of the flow volume loop curve before and three, six and 12 months after treatment with 131I. FIF50% increased over 12 months from median 1.79 l/sec (range 1.46-3.02) to 2.84 l/sec (1.13-5.69) (p = 0.01). A progressive increase was seen over time (p = 0.001, trend analysis). The FEF50%/FIF50% ratio decreased from in 1.45 (0.32-2.26) to 1.03 (0.43-2.13) 12 months after treatment (p < 0.001). A progressive decrease was seen over time (p = 0.001, trend analysis). By visual evaluation 11 had a flow volume loop curve typical for an upper airway obstruction and in 9 patients the FEF50%/FIF50% ratio was > 1.2. In conclusion we found that upper airway obstruction is present in patients with multinodular nontoxic goiter, and seems to be reduced after 131I-treatment. Flow volume loop curves and measurement of FEF50% and FIF50% are important estimates for upper airway obstruction in these patients.

Aged↗
PubMed1996

Marked hepatotoxicity associated with losartan treatment.

Losartan represent a novel approach in the treatment of hypertension. Clinical trials have reported a very low incidence of side effects. We describe two patients who developed increases in alanine/aspartate amino transferase of 8 and 15 times the upper normal limit, as well as thoracic pain, after a short time of treatment with losartan. The increase resolved after discontinuing losartan treatment.

Angiotensin Receptor Antagonists↗
PubMed1995

[Does Iodine 131 treatment of goiter result in an acute increase of the volume and function of the thyroid gland?].

Many textbooks claim that radioiodine (131I) treatment should be avoided in treatment of a goitre with substernal extension, due to fear of acute swelling of the gland with resulting respiratory problems. We examined patients with multinodular goitre, either nontoxic (n = 20) or toxic (n = 10) after treatment with 131I. An ultrasonically determined thyroid volume and thyroid function variables were investigated before and two, seven, 14, 21, 28 and 35 days after treatment. In nontoxic goitres the thyroid volume did not increase significantly, the maximum increase in the median volume being 4% on day 7. Serum levels of free T3 and free T4 indices increased by 20% (day 7) and 13% (day 14) (p = 0.002), respectively. Likewise thyroid volume in toxic nodular goitre did not change significantly after 131I treatment. None of the patients presented symptoms of tracheal compression. We conclude that 131I treatment of nontoxic as well as toxic multinodular goitre does not seem to increase thyroid volume.

Adult↗
PubMed1995

[False results on elevated triiodothyronine values in radioimmunoassay].

Five patients with falsely elevated serum triiodothyronine (T3) concentrations (> 9 nmol/l) in a radioimmunoassay are reported. The high T3-values disagreed with the other thyroid variables investigated as well as with the clinical observations. In sera from all patients a normal non-specific binding of T3 was found, thus excluding abnormal serum-protein-binding of the hormone. An ethanol extraction of T3 from serum before RIA reduced the T3 content in serum from all patients to normal levels (2.0-2.4 nmol/l). These findings indicate the presence in the sera of substances, probably of protein nature, that were interfering with the assay by binding the reagent-antibody and not the antigen. Addition of non-immune rabbit serum prevented this interference and normalized the T3-values (1.8-2.4 nmol/l). Thus the interfering substance in T3-RIA could be an anti-rabbit antibody, the interaction of which can be eliminated by a minor modification of the assay making it possible to differentiate true from false T3-values.

Adult↗
PubMed1995

[Problems in thyroid function screening using thyroid stimulating hormone. A case of thyrotoxicosis caused by a thyroid stimulating hormone-secreting pituitary tumor].

UNLABELLED: In a new consensus report from the Danish Society of Internal Medicine a sensitive TSH assay is recommended for screening for thyroid diseases. A patient with thyrotoxicosis, normal serum TSH and a TSH-secreting pituitary adenoma is described. Other reasons for discrepancies between thyroid clinical status and serum TSH are mentioned: Target organ resistance to thyroid hormone, interference in the radioimmunoassay with heterophilic antibodies and insufficient production of TSH because of pituitary disease. IN CONCLUSION: Screening with TSH is acceptable, but if any discrepancy between TSH values and the clinical picture is found, further tests must be made.

Adenoma↗
PubMed1995

Is calculation of the dose in radioiodine therapy of hyperthyroidism worth while?

OBJECTIVE: The persistent controversy as to the best approach to radioiodine dose selection in the treatment of hyperthyroidism led us to perform a study in order to compare a fixed dose regime comprising doses of 185 370 or 555 MBq based on gland size assessment by palpation only, with a calculated 131I dose based on type of thyroid gland (diffuse, multinodular, solitary adenoma), an accurate thyroid volume measurement, and a 24-hour 131I uptake determination. DESIGN: Prospective randomized study. PATIENTS: Two hundred and twenty-one consecutive hyperthyroid patients referred for 131I treatment. Four Patients who died for reasons unrelated to hyperthyroidism, 7 lost to follow-up and 47 who did not receive antithyroid drugs after treatment, were excluded. The remaining 163 patients (143 women) were studied, divided into subgroups according to the type of gland. They all received antithyroid drugs prior to 131I treatment and this was resumed 7 days after treatment for a period of 3 weeks. MEASUREMENTS: Thyroid function variables were determined approximately 2 weeks before 131I treatment, and again 1, 2, 3, 6, 9 and 12 months after treatment. Prior to 131I therapy the size of the thyroid gland was determined by ultrasound and a 24-hour uptake of 131I was carried out. Thyroid volume was also estimated 12 months after 131I therapy in 78 of the 163 patients. Twelve months after the initial 131I dose patients could be classified as euthyroid, hyperthyroid or hypothyroid. RESULTS: Neither in the group of 163 patients nor within the three subgroups of hyperthyroidism could any significant difference in outcome between the two treatment regimes be demonstrated. Thirty-two of 78 patients (41%) in the calculated dose group and 30 of 85 patients (35%, NS) in the fixed group were classified as hyperthyroid. Seven of 78 (9%) in the calculated dose group and 6 out of 85 (7%, NS) in the fixed dose group were classified as permanently hypothyroid. Finally, 39 of 78 (50%) in the calculated dose group and 49 of 85 (58%, NS) in the fixed group were euthyroid at 12 months after 131I treatment. One year after 131I therapy thyroid volume was reduced from 59.3 +/- 9.2 (mean +/- SEM) to 36.2 +/- 6.6 ml (average reduction 39%) in the calculated dose group (P < 0.001). This reduction did not differ significantly from the fixed dose group where thyroid volume declined from 61.6 +/- 6.1 to 41.17 +/- 4.7 ml (average reduction 32%) (P < 0.001). CONCLUSIONS: A semiquantitative approach is probably as good as the more elaborately calculated radioiodine dose for treatment of hyperthyroidism. It is clearly more cost effective and allows the use of predetermined standard doses.

Adult↗
PubMed1995

Influence of compensated radioiodine therapy on thyroid volume and incidence of hypothyroidism in Graves' disease.

OBJECTIVES: To investigate the long-term effect of radioactive iodine (131I) on thyroid function and size in patients with Graves' disease. SETTING: Out-patient clinic in Herlev Hospital. SUBJECTS: One hundred and seventeen consecutive patients (104 women) with Graves' disease selected for 131I treatment and followed for a minimum of 12 months (range 1-10 years, median 5 years). INTERVENTIONS: 131I dose was calculated based on thyroid volume and 24-h 131I uptake. MAIN OUTCOME MEASURES: Standard thyroid function variables and ultrasonically determined thyroid volume before treatment as well as 0.75, 1.5, 3, 6 and 12 months after treatment, and then once a year were investigated. RESULTS: Seventy-eight patients were cured by one 131I dose and 30 by two doses, while the remaining nine patients received additional doses (range one to five doses, median one dose). Within one year, 25% developed hypothyroidism, and hereafter, hypothyroidism developed at a constant rate of 3% per year independent of antithyroid pretreatment. The cumulative 10-year risk of hypothyroidism was 60%. Initial median thyroid volume was 33 mL (range 9-106 mL). At 12 months after the last 131I dose, median thyroid volume was reduced to 14 mL (range 6-36 mL) (P < 0.00001). The median reduction being 58% (range 0-80%), hereafter no further reduction occurred. A significant reduction in thyroid volume was also noted in patients needing subsequent 131I doses and in those developing hypothyroidism within the first year. CONCLUSIONS: 131I normalizes thyroid volume in patients with Graves' disease. Hypothyroidism seems an inevitable end result of this treatment. The present study suggests that it will be impossible to modify 131I therapy in a way to achieve both early control of hyperthyroidism and a low incidence of hypothyroidism.

Adult↗